* [PATCH net-next v7 3/3] dpll: add SiTime SiT9531x DPLL clock driver
2026-08-15 22:19 [PATCH net-next v7 0/3] dpll: add SiTime SiT9531x DPLL clock driver Ali Rouhi
2026-08-15 22:19 ` [PATCH net-next v7 1/3] dt-bindings: vendor-prefixes: add SiTime Corporation Ali Rouhi
2026-08-15 22:19 ` [PATCH net-next v7 2/3] dt-bindings: dpll: add SiTime SiT95316 clock generator Ali Rouhi
@ 2026-08-15 22:19 ` Ali Rouhi
2 siblings, 0 replies; 4+ messages in thread
From: Ali Rouhi @ 2026-08-15 22:19 UTC (permalink / raw)
To: jiri@resnulli.us
Cc: vadim.fedorenko@linux.dev, arkadiusz.kubalewski@intel.com,
robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org,
cjubran@nvidia.com, Oleg.Zadorozhnyi@devoxsoftware.com,
devicetree@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Ali Rouhi
Add a DPLL subsystem driver for the SiTime SiT95316 and SiT95317
clock generators. These devices provide low-jitter clock outputs
commonly used in telecom, networking, and data center timing
applications.
The driver exposes all inputs and outputs through the Linux DPLL
subsystem, supporting:
- Lock status monitoring via register polling or optional INTRB IRQ
- Input priority management for automatic reference switchover
- Per-output frequency readback from hardware state
- Phase offset measurement via TDC (time-to-digital converter)
- Phase adjustment for fine output alignment
- Embedded sync (esync) pulse control on outputs
- Fractional frequency offset of the selected reference
- Optional reset-gpios for hardware reset
The driver reads all configuration from the device's on-chip NVM
at probe time -- no firmware loading is required.
Co-developed-by: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
Signed-off-by: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
Assisted-by: Claude:claude-4-opus [chat]
Signed-off-by: Ali Rouhi <arouhi@sitime.com>
---
MAINTAINERS | 7 +
drivers/dpll/Kconfig | 1 +
drivers/dpll/Makefile | 1 +
drivers/dpll/sit9531x/Kconfig | 17 +
drivers/dpll/sit9531x/Makefile | 4 +
drivers/dpll/sit9531x/core.c | 3111 ++++++++++++++++++++++++++++++++
drivers/dpll/sit9531x/core.h | 372 ++++
drivers/dpll/sit9531x/dpll.c | 1232 +++++++++++++
drivers/dpll/sit9531x/dpll.h | 69 +
drivers/dpll/sit9531x/prop.c | 397 ++++
drivers/dpll/sit9531x/prop.h | 39 +
drivers/dpll/sit9531x/regs.h | 371 ++++
12 files changed, 5621 insertions(+)
create mode 100644 drivers/dpll/sit9531x/Kconfig
create mode 100644 drivers/dpll/sit9531x/Makefile
create mode 100644 drivers/dpll/sit9531x/core.c
create mode 100644 drivers/dpll/sit9531x/core.h
create mode 100644 drivers/dpll/sit9531x/dpll.c
create mode 100644 drivers/dpll/sit9531x/dpll.h
create mode 100644 drivers/dpll/sit9531x/prop.c
create mode 100644 drivers/dpll/sit9531x/prop.h
create mode 100644 drivers/dpll/sit9531x/regs.h
diff --git a/MAINTAINERS b/MAINTAINERS
index a82b6ec9c567..8dfab3ac6a17 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24905,6 +24905,13 @@ S: Maintained
W: http://www.winischhofer.at/linuxsisusbvga.shtml
F: drivers/usb/misc/sisusbvga/
+SITIME SIT9531X DPLL DRIVER
+M: Ali Rouhi <arouhi@sitime.com>
+L: netdev@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/dpll/sitime,sit95316.yaml
+F: drivers/dpll/sit9531x/
+
SL28 CPLD MFD DRIVER
M: Michael Walle <mwalle@kernel.org>
S: Maintained
diff --git a/drivers/dpll/Kconfig b/drivers/dpll/Kconfig
index be98969f040a..ea77b9c11ab1 100644
--- a/drivers/dpll/Kconfig
+++ b/drivers/dpll/Kconfig
@@ -23,6 +23,7 @@ config DPLL_REFCNT_TRACKER
If unsure, say N.
+source "drivers/dpll/sit9531x/Kconfig"
source "drivers/dpll/zl3073x/Kconfig"
endmenu
diff --git a/drivers/dpll/Makefile b/drivers/dpll/Makefile
index 9e7a3a3e592e..4adc50d748d4 100644
--- a/drivers/dpll/Makefile
+++ b/drivers/dpll/Makefile
@@ -8,4 +8,5 @@ dpll-y += dpll_core.o
dpll-y += dpll_netlink.o
dpll-y += dpll_nl.o
+obj-$(CONFIG_SIT9531X_DPLL) += sit9531x/
obj-$(CONFIG_ZL3073X) += zl3073x/
diff --git a/drivers/dpll/sit9531x/Kconfig b/drivers/dpll/sit9531x/Kconfig
new file mode 100644
index 000000000000..47aea8674327
--- /dev/null
+++ b/drivers/dpll/sit9531x/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config SIT9531X_DPLL
+ tristate "SiTime SiT9531x DPLL driver"
+ depends on I2C && NET
+ select DPLL
+ select REGMAP_I2C
+ help
+ Driver for SiTime SiT9531x family clock generators
+ (SiT95317, SiT95316).
+
+ This driver registers each on-chip PLL as a DPLL device
+ and exposes input/output clocks as DPLL pins, providing
+ runtime configuration via Generic Netlink.
+
+ To compile this driver as a module, choose M here: the
+ module will be called sit9531x.
diff --git a/drivers/dpll/sit9531x/Makefile b/drivers/dpll/sit9531x/Makefile
new file mode 100644
index 000000000000..b97d2656a460
--- /dev/null
+++ b/drivers/dpll/sit9531x/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_SIT9531X_DPLL) += sit9531x.o
+sit9531x-y := core.o dpll.o prop.o
diff --git a/drivers/dpll/sit9531x/core.c b/drivers/dpll/sit9531x/core.c
new file mode 100644
index 000000000000..cd283922e7ff
--- /dev/null
+++ b/drivers/dpll/sit9531x/core.c
@@ -0,0 +1,3111 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SiTime SiT9531x DPLL core driver
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ *
+ * Core I2C probe, regmap configuration, hardware state management,
+ * and periodic work thread.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "core.h"
+#include "dpll.h"
+#include "prop.h"
+#include "regs.h"
+
+/* Number of input + output pin positions for pin index allocation */
+#define SIT9531X_NUM_INPUT_PINS (SIT9531X_MAX_INPUTS + 2) /* +xtal +INTSYNC */
+#define SIT9531X_NUM_OUTPUT_PINS (SIT9531X_MAX_OUTPUTS + 1) /* +INTSYNC src */
+#define SIT9531X_NUM_PINS_TOTAL (SIT9531X_NUM_INPUT_PINS + SIT9531X_NUM_OUTPUT_PINS)
+
+#define SIT9531X_CHIP(_id, _nin, _nout, _name, _map) \
+ { .id = (_id), .num_inputs = (_nin), .num_outputs = (_nout), \
+ .name = (_name), .clkout_map = (_map) }
+
+/* Per-variant output index -> physical slot mapping */
+static const u8 clkout_map_95317[] = {0, 3, 4, 5, 7, 8, 9, 11};
+static const u8 clkout_map_95316[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
+
+static const struct sit9531x_chip_info sit9531x_chip_ids[] = {
+ SIT9531X_CHIP(SIT9531X_VARIANT_ID_95317, 8, 8, "SiT95317", clkout_map_95317),
+ SIT9531X_CHIP(SIT9531X_VARIANT_ID_95316, 8, 12, "SiT95316", clkout_map_95316),
+};
+
+#define SIT9531X_RANGE_OFFSET SIT9531X_PAGE_SIZE
+
+static const struct regmap_range_cfg sit9531x_regmap_range = {
+ .range_min = SIT9531X_RANGE_OFFSET,
+ .range_max = SIT9531X_RANGE_OFFSET +
+ (SIT9531X_NUM_PAGES * SIT9531X_PAGE_SIZE) - 1,
+ .selector_reg = SIT9531X_PAGE_SEL,
+ .selector_mask = GENMASK(7, 0),
+ .selector_shift = 0,
+ .window_start = 0,
+ .window_len = SIT9531X_PAGE_SIZE,
+};
+
+const struct regmap_config sit9531x_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = SIT9531X_RANGE_OFFSET +
+ (SIT9531X_NUM_PAGES * SIT9531X_PAGE_SIZE) - 1,
+ .ranges = &sit9531x_regmap_range,
+ .num_ranges = 1,
+ .cache_type = REGCACHE_NONE,
+};
+
+/*
+ * sit9531x_read_u8 - read an 8-bit register
+ * @reg: register in SIT9531X_REG(page, offset) form
+ * @val: output value
+ */
+int sit9531x_read_u8(struct sit9531x_dev *sitdev, unsigned int reg,
+ u8 *val)
+{
+ unsigned int tmp;
+ int rc;
+
+ reg = (SIT9531X_REG_PAGE(reg) * SIT9531X_PAGE_SIZE) +
+ SIT9531X_REG_OFFSET(reg) + SIT9531X_RANGE_OFFSET;
+
+ rc = regmap_read(sitdev->regmap, reg, &tmp);
+ if (rc)
+ dev_err(sitdev->dev, "Failed to read reg 0x%04x: %d\n",
+ reg, rc);
+ else
+ *val = (u8)tmp;
+
+ return rc;
+}
+
+/*
+ * sit9531x_write_u8 - write an 8-bit register
+ * @reg: register in SIT9531X_REG(page, offset) form
+ * @val: value to write
+ */
+int sit9531x_write_u8(struct sit9531x_dev *sitdev, unsigned int reg,
+ u8 val)
+{
+ int rc;
+
+ reg = (SIT9531X_REG_PAGE(reg) * SIT9531X_PAGE_SIZE) +
+ SIT9531X_REG_OFFSET(reg) + SIT9531X_RANGE_OFFSET;
+
+ rc = regmap_write(sitdev->regmap, reg, val);
+ if (rc)
+ dev_err(sitdev->dev, "Failed to write reg 0x%04x: %d\n",
+ reg, rc);
+
+ return rc;
+}
+
+/*
+ * sit9531x_read_pll_u8 - read a register on a PLL page
+ * @val: output value
+ */
+int sit9531x_read_pll_u8(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 offset, u8 *val)
+{
+ return sit9531x_read_u8(sitdev,
+ SIT9531X_REG(sit9531x_pll_page(pll_idx), offset),
+ val);
+}
+
+/*
+ * sit9531x_write_pll_u8 - write a register on a PLL page
+ * @val: value to write
+ */
+int sit9531x_write_pll_u8(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 offset, u8 val)
+{
+ return sit9531x_write_u8(sitdev,
+ SIT9531X_REG(sit9531x_pll_page(pll_idx), offset),
+ val);
+}
+
+/*
+ * sit9531x_update_pll_u8 - read-modify-write a register on a PLL page
+ * @mask: bits to modify
+ * @val: new value for masked bits
+ */
+int sit9531x_update_pll_u8(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 offset, u8 mask, u8 val)
+{
+ unsigned int reg;
+
+ reg = (sit9531x_pll_page(pll_idx) * SIT9531X_PAGE_SIZE) +
+ offset + SIT9531X_RANGE_OFFSET;
+
+ return regmap_update_bits(sitdev->regmap, reg, mask, val);
+}
+
+/*
+ * sit9531x_input_get_regs - get force mask and state register addresses
+ * @index: logical input index
+ * @force_reg: output force mask register address
+ * @state_reg: output state register address
+ *
+ * Selects the correct Page 0x02 register pair based on the pair's
+ * signal mode and the lane (P/N) the index refers to.
+ */
+static void sit9531x_input_get_regs(const struct sit9531x_dev *sitdev,
+ u8 index,
+ unsigned int *force_reg,
+ unsigned int *state_reg)
+{
+ if (sitdev->ref[index].sig_mode == SIT9531X_MODE_DE) {
+ *force_reg = SIT9531X_REG_IN_DE_FORCE;
+ *state_reg = SIT9531X_REG_IN_DE_STATE;
+ } else if (sit9531x_input_is_n(index)) {
+ *force_reg = SIT9531X_REG_IN_SEN_FORCE;
+ *state_reg = SIT9531X_REG_IN_SEN_STATE;
+ } else {
+ *force_reg = SIT9531X_REG_IN_SEP_FORCE;
+ *state_reg = SIT9531X_REG_IN_SEP_STATE;
+ }
+}
+
+/*
+ * sit9531x_input_disable - disable an input reference
+ * @index: logical input index (0-N)
+ *
+ * Sets the force mask bit and clears the state bit for the given
+ * input, effectively disabling it. Register selection depends on
+ * the pair's signal mode (SE/DE) and the lane (P/N); the bit within
+ * each register addresses the input pair.
+ */
+int sit9531x_input_disable(struct sit9531x_dev *sitdev, u8 index)
+{
+ struct sit9531x_ref *ref = &sitdev->ref[index];
+ unsigned int force_reg, state_reg;
+ u8 pair = sit9531x_input_pair(index);
+ u8 val;
+ int rc;
+
+ sit9531x_input_get_regs(sitdev, index, &force_reg, &state_reg);
+
+ rc = sit9531x_read_u8(sitdev, force_reg, &val);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, force_reg, val | BIT(pair));
+ if (rc)
+ return rc;
+
+ rc = sit9531x_read_u8(sitdev, state_reg, &val);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, state_reg, val & ~BIT(pair));
+ if (rc)
+ return rc;
+
+ ref->enabled = false;
+
+ return 0;
+}
+
+/*
+ * sit9531x_input_enable - enable an input reference
+ * @index: logical input index (0-N)
+ *
+ * Clears the force mask bit for the given input, returning it to
+ * hardware default (enabled).
+ */
+int sit9531x_input_enable(struct sit9531x_dev *sitdev, u8 index)
+{
+ struct sit9531x_ref *ref = &sitdev->ref[index];
+ unsigned int force_reg, state_reg;
+ u8 pair = sit9531x_input_pair(index);
+ u8 val;
+ int rc;
+
+ sit9531x_input_get_regs(sitdev, index, &force_reg, &state_reg);
+
+ rc = sit9531x_read_u8(sitdev, force_reg, &val);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, force_reg, val & ~BIT(pair));
+ if (rc)
+ return rc;
+
+ ref->enabled = true;
+
+ return 0;
+}
+
+/*
+ * Output enable / disable (Hi-Z control)
+ *
+ * SiT9531x outputs can be configured as differential (DIFF) or
+ * single-ended (SE) depending on the factory blob. Each output slot
+ * has TWO Hi-Z force/state register pairs on Page 0x03 -- one for the
+ * DIFF path, one for the SE path.
+ *
+ * We write to BOTH pairs so the function mutes the output regardless
+ * of whether it's been configured DIFF or SE on this board.
+ *
+ * slot 0-7 :
+ * DIFF mask=0xF2 state=0xF3 SE mask=0xF8 state=0xF9
+ * slot 8-11:
+ * DIFF mask=0xF4 state=0xF5 SE mask=0xFA state=0xFB
+ *
+ * MASK bit = 1 -> driver takes control of that output's Hi-Z state
+ * STATE bit = 0 -> output is forced to Hi-Z (muted)
+ * STATE bit = 1 -> output is driven (active)
+ *
+ * The output "index" in the driver is logical; the physical slot comes
+ * from info->clkout_map[].
+ */
+
+struct sit9531x_hiz_regs {
+ unsigned int diff_mask;
+ unsigned int diff_state;
+ unsigned int se_mask;
+ unsigned int se_state;
+ u8 bit;
+};
+
+static void sit9531x_output_get_hiz_regs(u8 slot,
+ struct sit9531x_hiz_regs *r)
+{
+ if (slot <= 7) {
+ r->diff_mask = SIT9531X_REG_HIZ_DIFF_07_MASK;
+ r->diff_state = SIT9531X_REG_HIZ_DIFF_07_STATE;
+ r->se_mask = SIT9531X_REG_HIZ_SE_07_MASK;
+ r->se_state = SIT9531X_REG_HIZ_SE_07_STATE;
+ r->bit = slot;
+ } else {
+ r->diff_mask = SIT9531X_REG_HIZ_DIFF_811_MASK;
+ r->diff_state = SIT9531X_REG_HIZ_DIFF_811_STATE;
+ r->se_mask = SIT9531X_REG_HIZ_SE_811_MASK;
+ r->se_state = SIT9531X_REG_HIZ_SE_811_STATE;
+ r->bit = slot - 8;
+ }
+}
+
+/*
+ * Report whether a slot is currently forced into Hi-Z, i.e. the driver
+ * (or the blob) took control of the Hi-Z state (MASK bit set) and drives
+ * it low (STATE bit clear). Either register pair muting the slot counts,
+ * mirroring what sit9531x_output_disable() programs.
+ */
+static int sit9531x_output_forced_hiz(struct sit9531x_dev *sitdev, u8 slot,
+ bool *muted)
+{
+ struct sit9531x_hiz_regs r;
+ u8 mask, state;
+ int rc;
+
+ sit9531x_output_get_hiz_regs(slot, &r);
+
+ rc = sit9531x_read_u8(sitdev, r.diff_mask, &mask);
+ if (rc)
+ return rc;
+ rc = sit9531x_read_u8(sitdev, r.diff_state, &state);
+ if (rc)
+ return rc;
+
+ *muted = (mask & BIT(r.bit)) && !(state & BIT(r.bit));
+ if (*muted)
+ return 0;
+
+ rc = sit9531x_read_u8(sitdev, r.se_mask, &mask);
+ if (rc)
+ return rc;
+ rc = sit9531x_read_u8(sitdev, r.se_state, &state);
+ if (rc)
+ return rc;
+
+ *muted = (mask & BIT(r.bit)) && !(state & BIT(r.bit));
+
+ return 0;
+}
+
+static int sit9531x_hiz_set_bit(struct sit9531x_dev *sitdev,
+ unsigned int reg, u8 bit, bool set)
+{
+ u8 cur, new_val;
+ int rc;
+
+ rc = sit9531x_read_u8(sitdev, reg, &cur);
+ if (rc)
+ return rc;
+
+ new_val = set ? (cur | BIT(bit)) : (cur & ~BIT(bit));
+
+ return sit9531x_write_u8(sitdev, reg, new_val);
+}
+
+/*
+ * Enter the output-system programming state: unlock the debug
+ * registers on Page 3 and issue the PRG_CMD state command. Register
+ * writes that reconfigure the output system only take effect when
+ * they are made inside this state.
+ */
+static int sit9531x_prg_enter(struct sit9531x_dev *sitdev)
+{
+ int rc;
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_OUTSYS_DEBUG,
+ SIT9531X_DEBUG_UNLOCK_VAL);
+ if (rc)
+ return rc;
+
+ return sit9531x_write_u8(sitdev, SIT9531X_REG_PRG_DIR_GEN,
+ SIT9531X_PRG_CMD_STATE);
+}
+
+/*
+ * Commit a programming sequence started by sit9531x_prg_enter():
+ * update the NVM shadow and re-lock the loops. The sleep gives the
+ * hardware its required settling time after the loop-lock command;
+ * it is intentional despite the caller holding multiop_lock, as the
+ * whole NVM + lock sequence must be atomic.
+ */
+static int sit9531x_prg_commit(struct sit9531x_dev *sitdev)
+{
+ int rc;
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_PRG_DIR_GEN,
+ SIT9531X_UPDATE_NVM);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_PRG_DIR_GEN,
+ SIT9531X_LOOP_LOCK);
+ if (rc)
+ return rc;
+
+ msleep(100);
+
+ return 0;
+}
+
+/*
+ * sit9531x_output_disable - mute an output (force Hi-Z)
+ * @index: logical output index (0..info->num_outputs-1)
+ *
+ * Sets MASK+STATE on BOTH the DIFF and SE register pairs so that the
+ * output is muted regardless of its electrical configuration. The
+ * writes are wrapped in the PRG_CMD / NVM update / loop lock sequence
+ * so the new state is applied by the hardware.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_output_disable(struct sit9531x_dev *sitdev, u8 index)
+{
+ const struct sit9531x_chip_info *info = sitdev->info;
+ struct sit9531x_hiz_regs r;
+ u8 slot;
+ int rc, ret;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (index >= info->num_outputs)
+ return -EINVAL;
+
+ slot = info->clkout_map[index];
+ sit9531x_output_get_hiz_regs(slot, &r);
+
+ rc = sit9531x_prg_enter(sitdev);
+ if (rc)
+ return rc;
+
+ /* Take control (MASK=1) and mute (STATE=0) on both DIFF and SE */
+ rc = sit9531x_hiz_set_bit(sitdev, r.diff_mask, r.bit, true);
+ if (rc)
+ goto commit;
+ rc = sit9531x_hiz_set_bit(sitdev, r.diff_state, r.bit, false);
+ if (rc)
+ goto commit;
+ rc = sit9531x_hiz_set_bit(sitdev, r.se_mask, r.bit, true);
+ if (rc)
+ goto commit;
+ rc = sit9531x_hiz_set_bit(sitdev, r.se_state, r.bit, false);
+
+commit:
+ /*
+ * Always leave the PRG_CMD programming state, even on a mid-sequence
+ * write failure: prg_enter() unlocked the output loops, so returning
+ * without prg_commit() would strand the chip in the programming state
+ * with the loops unlocked. Best effort -- keep the first error.
+ */
+ ret = sit9531x_prg_commit(sitdev);
+ if (ret && !rc)
+ rc = ret;
+ if (!rc)
+ sitdev->out[index].enabled = false;
+
+ return rc;
+}
+
+/*
+ * sit9531x_output_enable - un-mute an output (active state)
+ * @index: logical output index (0..info->num_outputs-1)
+ *
+ * Releases MASK on BOTH register pairs so the output returns to
+ * whatever the initial_config blob programmed. The writes are wrapped
+ * in the PRG_CMD / NVM update / loop lock sequence so the new state is
+ * applied by the hardware.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_output_enable(struct sit9531x_dev *sitdev, u8 index)
+{
+ const struct sit9531x_chip_info *info = sitdev->info;
+ struct sit9531x_hiz_regs r;
+ u8 slot;
+ int rc, ret;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (index >= info->num_outputs)
+ return -EINVAL;
+
+ slot = info->clkout_map[index];
+ sit9531x_output_get_hiz_regs(slot, &r);
+
+ rc = sit9531x_prg_enter(sitdev);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_hiz_set_bit(sitdev, r.diff_mask, r.bit, false);
+ if (rc)
+ goto commit;
+ rc = sit9531x_hiz_set_bit(sitdev, r.se_mask, r.bit, false);
+
+commit:
+ /*
+ * Always leave the PRG_CMD programming state, even on a mid-sequence
+ * write failure: prg_enter() unlocked the output loops, so returning
+ * without prg_commit() would strand the chip in the programming state
+ * with the loops unlocked. Best effort -- keep the first error.
+ */
+ ret = sit9531x_prg_commit(sitdev);
+ if (ret && !rc)
+ rc = ret;
+ if (!rc)
+ sitdev->out[index].enabled = true;
+
+ return rc;
+}
+
+/*
+ * Input priority selection
+ *
+ * The SiT9531x has a 12-slot priority table per PLL on Page 1. Each
+ * register holds two slots nibble-packed (even slot in [3:0], odd slot
+ * in [7:4]).
+ *
+ * The procedure:
+ * 1. Force PLL into holdover (PLL page reg 0x6F bit 4)
+ * 2. Write priority slots on Page 1
+ * 3. Small change update (Page 0 reg 0x0F bit 1)
+ * 4. Release holdover
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+
+/* Page-1 register holding priority slot @slot of @pll_idx. */
+static u16 sit9531x_prio_reg(u8 pll_idx, u8 slot)
+{
+ return SIT9531X_REG(SIT9531X_PAGE_PRIOSYS,
+ SIT9531X_PRIO_BASE_REG +
+ SIT9531X_PRIO_REGS_PER_PLL * pll_idx +
+ slot / SIT9531X_PRIO_SLOTS_PER_REG);
+}
+
+/*
+ * Extract priority slot @slot from its register value. The register
+ * holding slots 2n and 2n+1 keeps the earlier slot in the high nibble
+ * (CLK_SPARE<2n>SEL) and the later one in the low nibble.
+ */
+static u8 sit9531x_prio_slot_get(u8 val, u8 slot)
+{
+ if (slot & 1)
+ return val & SIT9531X_PRIO_NIBBLE_MASK;
+
+ return val >> SIT9531X_PRIO_HI_SHIFT;
+}
+
+/* Place source @src in priority slot @slot of a register value. */
+static u8 sit9531x_prio_slot_set(u8 val, u8 slot, u8 src)
+{
+ if (slot & 1)
+ return (val & (SIT9531X_PRIO_NIBBLE_MASK <<
+ SIT9531X_PRIO_HI_SHIFT)) |
+ (src & SIT9531X_PRIO_NIBBLE_MASK);
+
+ return (val & SIT9531X_PRIO_NIBBLE_MASK) |
+ ((src & SIT9531X_PRIO_NIBBLE_MASK) <<
+ SIT9531X_PRIO_HI_SHIFT);
+}
+
+/*
+ * Commit a priority-table programming sequence through the Page-0
+ * programming directive register.
+ *
+ * A small change update is all the table needs. The NVM-bank and
+ * loop-lock directives that the output system issues do not belong
+ * here: the former programs non-volatile storage from the efuse and
+ * the latter only means anything after an escape to the PRG_CMD
+ * state. This matches the vendor input_priority_sel() procedure.
+ */
+static int sit9531x_prio_prg_commit(struct sit9531x_dev *sitdev)
+{
+ int rc;
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_GLOBAL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc)
+ return rc;
+
+ usleep_range(1000, 2000);
+
+ return 0;
+}
+
+/*
+ * sit9531x_input_prio_get - read an input's priority slot for a PLL
+ * @input_idx: input source in hardware encoding (see
+ * sit9531x_input_hw_src())
+ * @prio: output slot position (0 = highest); set to
+ * SIT9531X_PRIO_MAX_SLOTS when the source is not in the table
+ *
+ * Scans the PLL's 12-slot priority table on Page 1 and returns the
+ * highest-priority (lowest-numbered) slot that references the source.
+ * This reads the value the chip actually holds rather than a cached
+ * default, so pin-get reflects the real hardware priority.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_input_prio_get(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx, u8 *prio)
+{
+ u8 val, slot, src;
+ int rc;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ for (slot = 0; slot < SIT9531X_PRIO_MAX_SLOTS; slot++) {
+ rc = sit9531x_read_u8(sitdev,
+ sit9531x_prio_reg(pll_idx, slot), &val);
+ if (rc)
+ return rc;
+
+ src = sit9531x_prio_slot_get(val, slot);
+
+ if (src == input_idx) {
+ *prio = slot;
+ return 0;
+ }
+ }
+
+ *prio = SIT9531X_PRIO_MAX_SLOTS;
+ return 0;
+}
+
+/*
+ * sit9531x_prio_table_commit - write a full priority table for a PLL
+ * @srcs: array of SIT9531X_PRIO_MAX_SLOTS source codes, slot 0 first
+ *
+ * Programs all priority slots (nibble-packed, two per register) for
+ * the PLL using the same holdover / small-update sequence as
+ * sit9531x_input_prio_set(). Caller must hold sitdev->multiop_lock.
+ */
+static int sit9531x_prio_table_commit(struct sit9531x_dev *sitdev, u8 pll_idx,
+ const u8 *srcs)
+{
+ u8 val, slot;
+ int rc, prg_rc, ho_rc;
+ u16 reg;
+
+ rc = sit9531x_update_pll_u8(sitdev, pll_idx, SIT9531X_PLL_REG_HO_CTRL,
+ BIT(SIT9531X_PLL_HO_FORCE_BIT),
+ BIT(SIT9531X_PLL_HO_FORCE_BIT));
+ if (rc)
+ return rc;
+
+ usleep_range(10000, 12000);
+
+ for (slot = 0; slot < SIT9531X_PRIO_MAX_SLOTS; slot++) {
+ reg = sit9531x_prio_reg(pll_idx, slot);
+
+ rc = sit9531x_read_u8(sitdev, reg, &val);
+ if (rc)
+ goto commit;
+
+ val = sit9531x_prio_slot_set(val, slot, srcs[slot]);
+
+ rc = sit9531x_write_u8(sitdev, reg, val);
+ if (rc)
+ goto commit;
+ }
+
+commit:
+ /* Latch unconditionally, as in sit9531x_input_prio_set(). */
+ prg_rc = sit9531x_prio_prg_commit(sitdev);
+ if (prg_rc && !rc)
+ rc = prg_rc;
+
+ ho_rc = sit9531x_update_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_HO_CTRL,
+ BIT(SIT9531X_PLL_HO_FORCE_BIT), 0);
+ if (ho_rc && !rc)
+ rc = ho_rc;
+
+ return rc;
+}
+
+/*
+ * sit9531x_prio_table_read - read a PLL's priority-table source codes
+ * @srcs: output array of SIT9531X_PRIO_MAX_SLOTS source codes
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+static int sit9531x_prio_table_read(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 *srcs)
+{
+ u8 val, slot;
+ int rc;
+
+ for (slot = 0; slot < SIT9531X_PRIO_MAX_SLOTS; slot++) {
+ rc = sit9531x_read_u8(sitdev,
+ sit9531x_prio_reg(pll_idx, slot), &val);
+ if (rc)
+ return rc;
+
+ srcs[slot] = sit9531x_prio_slot_get(val, slot);
+ }
+
+ return 0;
+}
+
+/*
+ * sit9531x_input_prio_set - move an input to a priority slot
+ * @input_idx: input source in hardware encoding (0-11, see
+ * sit9531x_input_hw_src())
+ * @prio: priority slot position (0 = highest)
+ *
+ * Reads the PLL's table, takes the source out of wherever it sits and
+ * reinserts it at @prio, shifting the entries in between. The rest keep
+ * their relative order: a priority change asks about one input, so the
+ * fallbacks configured behind it have to survive it.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ *
+ * Return: 0 on success, <0 on error
+ */
+int sit9531x_input_prio_set(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx, u8 prio)
+{
+ u8 srcs[SIT9531X_PRIO_MAX_SLOTS];
+ u8 slot, from;
+ int rc;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+ if (input_idx >= SIT9531X_PRIO_NUM_SRC)
+ return -EINVAL;
+ if (prio >= SIT9531X_PRIO_MAX_SLOTS)
+ return -EINVAL;
+
+ rc = sit9531x_prio_table_read(sitdev, pll_idx, srcs);
+ if (rc)
+ return rc;
+
+ for (from = 0; from < SIT9531X_PRIO_MAX_SLOTS; from++)
+ if (srcs[from] == input_idx)
+ break;
+
+ if (from == prio)
+ return 0;
+
+ if (from > prio) {
+ /*
+ * Moving up, or not in the table at all: push the tail down
+ * to open the slot. For a source that is new, whatever sat
+ * in the last slot falls off -- the entry the chip would have
+ * tried last.
+ */
+ if (from == SIT9531X_PRIO_MAX_SLOTS)
+ from = SIT9531X_PRIO_MAX_SLOTS - 1;
+ for (slot = from; slot > prio; slot--)
+ srcs[slot] = srcs[slot - 1];
+ } else {
+ for (slot = from; slot < prio; slot++)
+ srcs[slot] = srcs[slot + 1];
+ }
+
+ srcs[prio] = input_idx;
+
+ return sit9531x_prio_table_commit(sitdev, pll_idx, srcs);
+}
+
+/*
+ * sit9531x_input_prio_remove - drop an input from a PLL's priority table
+ * @input_idx: input source in hardware encoding
+ *
+ * Rewrites the priority table with the source removed: the remaining
+ * sources are compacted toward the highest-priority slots and the freed
+ * tail slots are backfilled with the lowest-priority remaining source
+ * (matching sit9531x_input_prio_set()). This makes a disconnected
+ * input ineligible for automatic reference selection, not just gated at
+ * the input buffer. It is a no-op when the source is absent, or when it
+ * is the only source (the buffer disable then drives the PLL to
+ * holdover and the table must not be left empty).
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_input_prio_remove(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx)
+{
+ u8 srcs[SIT9531X_PRIO_MAX_SLOTS];
+ u8 kept[SIT9531X_PRIO_MAX_SLOTS];
+ u8 slot, count = 0;
+ bool found = false;
+ int rc;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ rc = sit9531x_prio_table_read(sitdev, pll_idx, srcs);
+ if (rc)
+ return rc;
+
+ for (slot = 0; slot < SIT9531X_PRIO_MAX_SLOTS; slot++) {
+ if (srcs[slot] == input_idx)
+ found = true;
+ else
+ kept[count++] = srcs[slot];
+ }
+
+ if (!found || count == 0)
+ return 0;
+
+ /* Backfill freed tail slots with the lowest-priority remaining src */
+ while (count < SIT9531X_PRIO_MAX_SLOTS) {
+ kept[count] = kept[count - 1];
+ count++;
+ }
+
+ return sit9531x_prio_table_commit(sitdev, pll_idx, kept);
+}
+
+/*
+ * sit9531x_input_prio_add - make an input eligible in a PLL's table
+ * @input_idx: input source in hardware encoding
+ *
+ * Ensures the source appears in the priority table so it can be picked
+ * by automatic reference selection again after a disconnect. If the
+ * source is already listed the table is left untouched; otherwise it is
+ * placed in the lowest-priority slot. The original priority is not
+ * restored -- use sit9531x_input_prio_set() to reassign it.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_input_prio_add(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx)
+{
+ u8 srcs[SIT9531X_PRIO_MAX_SLOTS];
+ u8 slot;
+ int rc;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ rc = sit9531x_prio_table_read(sitdev, pll_idx, srcs);
+ if (rc)
+ return rc;
+
+ for (slot = 0; slot < SIT9531X_PRIO_MAX_SLOTS; slot++)
+ if (srcs[slot] == input_idx)
+ return 0;
+
+ srcs[SIT9531X_PRIO_MAX_SLOTS - 1] = input_idx;
+
+ return sit9531x_prio_table_commit(sitdev, pll_idx, srcs);
+}
+
+/* Per-slot DIVO base register offsets (6 slots per page) */
+static const u8 clkout_odr_divn_base[] = {
+ 0x14, 0x24, 0x34, 0x44, 0x54, 0x64
+};
+
+/* XO doubler register */
+#define SIT9531X_REG_XO2_GENERIC SIT9531X_REG(0x00, 0x2D)
+#define SIT9531X_XO_DOUBLER_ENB_BIT 7 /* inverted: 0 = enabled */
+
+/* VCO frequency bands (Hz) */
+#define SIT9531X_FVCO_LOWBAND_MIN 4915200000ULL
+#define SIT9531X_FVCO_LOWBAND_MAX 5898240000ULL
+#define SIT9531X_FVCO_HIGHBAND_MIN 6875000000ULL
+#define SIT9531X_FVCO_HIGHBAND_MAX 7812500000ULL
+
+/*
+ * sit9531x_is_xo_doubler_enabled - check if Fref doubler is active
+ *
+ * Register 0x2D bit 7 is active-low: 0 = doubler enabled, 1 = disabled.
+ *
+ * Return: 1 if enabled, 0 if disabled, <0 on error
+ */
+static int sit9531x_is_xo_doubler_enabled(struct sit9531x_dev *sitdev)
+{
+ u8 val;
+ int rc;
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_XO2_GENERIC, &val);
+ if (rc)
+ return rc;
+
+ return (~val >> SIT9531X_XO_DOUBLER_ENB_BIT) & 1u;
+}
+
+/*
+ * sit9531x_dbg_sample - latch and read a signal pathway debug sample
+ * @sitdev: device pointer
+ * @pll_idx: PLL index (0-3)
+ * @read_code: which tap of the pathway to sample
+ * @buf: result, least significant byte first
+ * @len: bytes to read, at most SIT9531X_DBG_DATA_BYTES
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int sit9531x_dbg_sample(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 read_code, u8 *buf, unsigned int len)
+{
+ unsigned int i;
+ int rc;
+ u8 v;
+
+ if (len > SIT9531X_DBG_DATA_BYTES)
+ return -EINVAL;
+
+ rc = sit9531x_write_pll_u8(sitdev, pll_idx, SIT9531X_PLL_REG_DEBUG,
+ SIT9531X_PLL_DEBUG_UNLOCK);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_write_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_READ_CODE, read_code);
+ if (rc)
+ return rc;
+
+ /* Reading the trigger latches a fresh sample of the selected tap. */
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_TRIGGER, &v);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < len; i++) {
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_DATA_0 + i,
+ &buf[i]);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+/*
+ * DIVN as a fixed-point value: int_part plus fracn/fracd, carried with
+ * SIT9531X_DIVN_SCALE steps per unit. The scale keeps a whole DIVN
+ * well inside s64 while resolving far below the parts-per-trillion the
+ * frequency offset is reported in.
+ */
+static s64 sit9531x_divn_fixed(u32 int_part, s64 fracn, u64 fracd)
+{
+ s64 whole = (s64)int_part * SIT9531X_DIVN_SCALE;
+ u64 frac;
+
+ if (!fracd)
+ return whole;
+
+ frac = mul_u64_u64_div_u64(abs(fracn), SIT9531X_DIVN_SCALE, fracd);
+
+ return fracn < 0 ? whole - (s64)frac : whole + (s64)frac;
+}
+
+/*
+ * sit9531x_divn_static - read the configured DIVN of a PLL
+ * @sitdev: device pointer
+ * @pll_idx: PLL index (0-3)
+ * @divn: result, fixed point as per sit9531x_divn_fixed()
+ *
+ * Reads PLL page regs 0x30 (integer part), 0x32-0x35 (numerator) and
+ * 0x38-0x3B (denominator). The numerator is a two's complement 32-bit
+ * value, so DIVN can sit below the integer part, and the denominator
+ * register holds the divisor minus one.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int sit9531x_divn_static(struct sit9531x_dev *sitdev, u8 pll_idx,
+ s64 *divn)
+{
+ u32 int_part, fracn_raw = 0, fracd_raw = 0;
+ int rc, i;
+ u8 v;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DIVN_INT, &v);
+ if (rc)
+ return rc;
+ int_part = v;
+
+ for (i = 3; i >= 0; i--) {
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DIVN_NUM + i, &v);
+ if (rc)
+ return rc;
+ fracn_raw = (fracn_raw << 8) | v;
+ }
+
+ for (i = 3; i >= 0; i--) {
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DIVN_DEN + i, &v);
+ if (rc)
+ return rc;
+ fracd_raw = (fracd_raw << 8) | v;
+ }
+
+ *divn = sit9531x_divn_fixed(int_part, (s32)fracn_raw,
+ (u64)fracd_raw + 1);
+
+ return 0;
+}
+
+/*
+ * sit9531x_divn_runtime - read the DIVN the digital loop is commanding
+ * @sitdev: device pointer
+ * @pll_idx: PLL index (0-3)
+ * @divn: result, fixed point as per sit9531x_divn_fixed()
+ *
+ * Same quantity as sit9531x_divn_static(), but sampled from the running
+ * loop rather than from the configuration registers, and carried at a
+ * wider precision: the numerator is 48 bits, two's complement, the
+ * denominator 49. The integer part shares its tap with the numerator.
+ *
+ * Return: 0 on success, <0 on error
+ */
+static int sit9531x_divn_runtime(struct sit9531x_dev *sitdev, u8 pll_idx,
+ s64 *divn)
+{
+ u8 buf[SIT9531X_DBG_DATA_BYTES];
+ u64 fracn_raw = 0, fracd = 0;
+ u32 int_part;
+ int rc, i;
+
+ rc = sit9531x_dbg_sample(sitdev, pll_idx, SIT9531X_DBG_READ_CODE_DIVN,
+ buf, SIT9531X_DBG_DATA_BYTES);
+ if (rc)
+ return rc;
+
+ for (i = 5; i >= 0; i--)
+ fracn_raw = (fracn_raw << 8) | buf[i];
+
+ int_part = buf[6] | ((u32)(buf[7] & SIT9531X_DIVN_RT_INT_HI_BIT) << 8);
+
+ rc = sit9531x_dbg_sample(sitdev, pll_idx,
+ SIT9531X_DBG_READ_CODE_DIVN_DEN, buf,
+ SIT9531X_DBG_DATA_BYTES);
+ if (rc)
+ return rc;
+
+ for (i = 5; i >= 0; i--)
+ fracd = (fracd << 8) | buf[i];
+
+ fracd |= (u64)(buf[6] & SIT9531X_DIVN_RT_INT_HI_BIT) << 48;
+
+ *divn = sit9531x_divn_fixed(int_part,
+ sign_extend64(fracn_raw,
+ SIT9531X_DIVN_RT_NUM_BITS - 1),
+ fracd);
+
+ return 0;
+}
+
+/**
+ * sit9531x_pll_ffo_ppt - fractional frequency offset of a PLL's reference
+ * @sitdev: device pointer
+ * @pll_idx: PLL index (0-3)
+ * @ffo: result in parts per trillion
+ *
+ * A locked PLL commands whatever DIVN keeps its VCO tracking the
+ * reference. How far that sits from the configured DIVN is how far the
+ * reference sits from the local oscillator, which is the fractional
+ * frequency offset the DPLL ABI reports for the pin feeding the device.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ *
+ * Return: 0 on success, -ENODATA when DIVN is not programmed, <0 on
+ * error.
+ */
+int sit9531x_pll_ffo_ppt(struct sit9531x_dev *sitdev, u8 pll_idx, s64 *ffo)
+{
+ s64 configured, running, delta;
+ u64 magnitude;
+ int rc;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ rc = sit9531x_divn_static(sitdev, pll_idx, &configured);
+ if (rc)
+ return rc;
+ if (configured <= 0)
+ return -ENODATA;
+
+ rc = sit9531x_divn_runtime(sitdev, pll_idx, &running);
+ if (rc)
+ return rc;
+
+ delta = running - configured;
+ magnitude = mul_u64_u64_div_u64(abs(delta), SIT9531X_PPT_PER_UNIT,
+ (u64)configured);
+
+ *ffo = delta < 0 ? -(s64)magnitude : (s64)magnitude;
+
+ return 0;
+}
+
+/*
+ * sit9531x_get_fvco - read VCO frequency from chip's DIVN registers
+ *
+ * Fvco = Fref * DIVN, where DIVN comes from sit9531x_divn_static() and
+ * Fref = xtal_freq << doubler. DIVN is the
+ * steady-state Fvco/Fref target programmed by the NVM blob and is
+ * authoritative in both free-run and sync modes; the previous split
+ * between free-run and sync formulas returned 0 on chips that didn't
+ * have a sync input populated, which broke the TDC phase readback.
+ *
+ * Return: Fvco in Hz, or 0 on error
+ */
+static u64 sit9531x_get_fvco(struct sit9531x_dev *sitdev, u8 pll_idx)
+{
+ int doubler, rc;
+ s64 divn;
+ u64 fref;
+
+ /*
+ * DT board-config override: some configs (e.g. an INTSYNC PLL)
+ * run a VCO that Fref*DIVN does not reproduce. When the board
+ * supplies the measured VCO, use it verbatim.
+ */
+ if (pll_idx < SIT9531X_NUM_PLLS && sitdev->pll_fvco[pll_idx])
+ return sitdev->pll_fvco[pll_idx];
+
+ rc = sit9531x_divn_static(sitdev, pll_idx, &divn);
+ if (rc || divn <= 0)
+ return 0;
+
+ doubler = sit9531x_is_xo_doubler_enabled(sitdev);
+ if (doubler < 0)
+ return 0;
+
+ fref = (u64)sitdev->xtal_freq << doubler;
+
+ return mul_u64_u64_div_u64(fref, (u64)divn, SIT9531X_DIVN_SCALE);
+}
+
+/*
+ * sit9531x_output_phase_flush - flush the output phase of a PLL
+ *
+ * Fires the chip's on-demand phase-flush (PHFL) so every output divider
+ * of @pll_idx restarts aligned to the PLL phase. Without it a rewritten
+ * DIVO keeps counting from an arbitrary point and the output edge lands
+ * with a persistent offset against the tracked reference (only a power
+ * cycle realigned it).
+ *
+ * The sequence mirrors the vendor procedure: arm the on-demand PHFL and
+ * latch it with the PLL-page small-change update, then select the
+ * in-register phase trigger on Page 0 and pulse it. The Page 0 trigger
+ * register is touched read-modify-write so the unrelated OEb bits are
+ * preserved.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+static int sit9531x_output_phase_flush(struct sit9531x_dev *sitdev, u8 pll_idx)
+{
+ u8 ctrl, orig;
+ int rc, ret;
+
+ /* Arm the on-demand phase-flush on the PLL page. */
+ rc = sit9531x_update_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_PHFL_CTRL,
+ SIT9531X_PLL_PHFL_ON_DEMAND_EN,
+ SIT9531X_PLL_PHFL_ON_DEMAND_EN);
+ if (rc)
+ return rc;
+
+ /* Latch it with the PLL small-change update. */
+ rc = sit9531x_update_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_SMALL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc)
+ return rc;
+
+ /*
+ * Select the in-register phase trigger, preserving the OEb bits.
+ * Remember the original register value (with the trigger de-asserted)
+ * so the trigger-source select can be restored once the pulse has
+ * fired.
+ */
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_GPIO_FUNC_CTRL1, &ctrl);
+ if (rc)
+ return rc;
+
+ orig = ctrl & ~SIT9531X_DIVO_PHASE_TRIG;
+ ctrl = orig | SIT9531X_DIVO_PHASE_SEL_REG;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_GPIO_FUNC_CTRL1, ctrl);
+ if (rc)
+ return rc;
+
+ /*
+ * Pulse the phase trigger. No explicit delay is needed between the
+ * set and clear writes: each I2C transaction takes far longer than
+ * any minimum pulse width.
+ */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_GPIO_FUNC_CTRL1,
+ ctrl | SIT9531X_DIVO_PHASE_TRIG);
+
+ /*
+ * Restore the original trigger-source select. The pulse above has
+ * already latched the flush, so a one-shot flush must not leave the
+ * phase trigger permanently pinned to the in-register source. This
+ * runs even when the pulse write failed, otherwise a failed flush
+ * would keep a hardware trigger source hijacked; the restore error
+ * is only surfaced when it would not mask the pulse failure.
+ */
+ ret = sit9531x_write_u8(sitdev, SIT9531X_REG_GPIO_FUNC_CTRL1, orig);
+ if (ret && !rc)
+ rc = ret;
+
+ return rc;
+}
+
+/*
+ * sit9531x_output_freq_set - set output clock frequency
+ * @out_idx: output index (0-N for this chip variant)
+ * @pll_idx: PLL driving this output (0-3)
+ * @frequency: desired output frequency in Hz
+ *
+ * Computes DIVO = Fvco / frequency and writes the 34-bit output divider
+ * to the output system registers on Pages 3/4. The write sequence is:
+ * 1. Unlock debug registers (Page 3)
+ * 2. Enter PRG_CMD state
+ * 3. Write 5-byte DIVO to the correct page/slot
+ * 4. NVM update
+ * 5. Loop lock
+ * 6. Wait for lock to settle
+ * 7. Flush the output phase so the new divider starts aligned
+ *
+ * Caller must hold sitdev->multiop_lock.
+ *
+ * Return: 0 on success, <0 on error. Actual frequency may differ
+ * due to integer division; the output state is updated with
+ * the effective frequency (Fvco / DIVO).
+ */
+int sit9531x_output_freq_set(struct sit9531x_dev *sitdev, u8 out_idx,
+ u8 pll_idx, u64 frequency)
+{
+ const struct sit9531x_chip_info *info = sitdev->info;
+ u8 slot, page, base_reg, divo_bytes[5], msb_old;
+ u64 fvco, divo, fvco_min, fvco_max;
+ int rc, j, ret;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (out_idx >= info->num_outputs || pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ if (!frequency)
+ return -EINVAL;
+
+ /* Determine VCO frequency band limits */
+ if (pll_idx == 1 || pll_idx == 3) {
+ /* PLLB, PLLD: high band */
+ fvco_min = SIT9531X_FVCO_HIGHBAND_MIN;
+ fvco_max = SIT9531X_FVCO_HIGHBAND_MAX;
+ } else {
+ /* PLLA, PLLC: low band */
+ fvco_min = SIT9531X_FVCO_LOWBAND_MIN;
+ fvco_max = SIT9531X_FVCO_LOWBAND_MAX;
+ }
+
+ /*
+ * Read current VCO frequency. When the board supplies an explicit
+ * Fvco via "sitime,pll-fvco" the override is the source of truth
+ * (e.g. a chip variant that runs out of the documented band, or a
+ * mode like INTSYNC where Fref*DIVN does not reproduce the VCO), so
+ * skip the band clamp in that case.
+ */
+ fvco = sit9531x_get_fvco(sitdev, pll_idx);
+ if (!fvco) {
+ fvco = fvco_min;
+ } else if (!sitdev->pll_fvco[pll_idx]) {
+ if (fvco < fvco_min)
+ fvco = fvco_min;
+ else if (fvco > fvco_max)
+ fvco = fvco_max;
+ }
+
+ divo = div64_u64(fvco, frequency);
+ if (!divo)
+ return -EINVAL;
+
+ dev_dbg(sitdev->dev,
+ "out%u: Fvco=%llu freq=%llu DIVO=%llu (effective %llu Hz)\n",
+ out_idx, fvco, frequency, divo, div64_u64(fvco, divo));
+
+ /* Map output index to physical slot */
+ slot = info->clkout_map[out_idx];
+
+ /* Determine page and per-page slot register */
+ if (slot > SIT9531X_PAGE_OUTSYS0_SLOT_MAX)
+ page = SIT9531X_PAGE_OUTSYS1;
+ else
+ page = SIT9531X_PAGE_OUTSYS0;
+ base_reg = clkout_odr_divn_base[slot % 6];
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_OUTSYS_DEBUG,
+ SIT9531X_DEBUG_UNLOCK_VAL);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_PRG_DIR_GEN,
+ SIT9531X_PRG_CMD_STATE);
+ if (rc)
+ return rc;
+
+ divo_bytes[0] = (divo >> 0) & 0xFF;
+ divo_bytes[1] = (divo >> 8) & 0xFF;
+ divo_bytes[2] = (divo >> 16) & 0xFF;
+ divo_bytes[3] = (divo >> 24) & 0xFF;
+ divo_bytes[4] = (divo >> 32) & 0x03; /* only bits [1:0] */
+
+ rc = sit9531x_read_u8(sitdev,
+ SIT9531X_REG(page, base_reg - 4), &msb_old);
+ if (rc)
+ goto commit;
+ divo_bytes[4] |= msb_old & 0xFC;
+
+ for (j = 0; j < 5; j++) {
+ rc = sit9531x_write_u8(sitdev,
+ SIT9531X_REG(page, base_reg - j),
+ divo_bytes[j]);
+ if (rc)
+ goto commit;
+ }
+
+commit:
+ /*
+ * Step 4: NVM update + loop lock. Always run prg_commit() so the chip
+ * leaves the PRG_CMD state with the output loops re-locked, even when a
+ * write above failed; keep the first error to return. It also carries
+ * the required post-lock settling sleep.
+ */
+ ret = sit9531x_prg_commit(sitdev);
+ if (ret && !rc)
+ rc = ret;
+ if (rc)
+ return rc;
+
+ /*
+ * Step 5: flush the PLL's output phase so the new DIVO starts
+ * aligned instead of keeping the arbitrary phase the divider
+ * happened to be at.
+ */
+ rc = sit9531x_output_phase_flush(sitdev, pll_idx);
+ if (rc)
+ return rc;
+
+ sitdev->out[out_idx].freq = (u32)div64_u64(fvco, divo);
+
+ return 0;
+}
+
+/*
+ * sit9531x_output_freq_get - read output clock frequency from hardware
+ * @out_idx: output index (0-N for this chip variant)
+ * @frequency: output frequency in Hz
+ *
+ * Reads the 34-bit DIVO divider back from the output system registers
+ * and computes the live output frequency as Fvco / DIVO. This stays
+ * correct even when the divider was reprogrammed behind the driver's
+ * back (e.g. by a direct-I2C userspace tool), where the cached value
+ * would be stale.
+ *
+ * The cached output state is refreshed with the computed value.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ *
+ * Return: 0 on success, -ENODEV when the output divider or VCO rate
+ * is not resolvable, <0 on register access error
+ */
+int sit9531x_output_freq_get(struct sit9531x_dev *sitdev, u8 out_idx,
+ u64 *frequency)
+{
+ const struct sit9531x_chip_info *info = sitdev->info;
+ u8 slot, page, base_reg, pll_idx, v;
+ u64 fvco, divo = 0;
+ int rc, j;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (out_idx >= info->num_outputs)
+ return -EINVAL;
+
+ pll_idx = sitdev->out[out_idx].pll_idx;
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -ENODEV;
+
+ fvco = sit9531x_get_fvco(sitdev, pll_idx);
+ if (!fvco)
+ return -ENODEV;
+
+ slot = info->clkout_map[out_idx];
+ if (slot > SIT9531X_PAGE_OUTSYS0_SLOT_MAX)
+ page = SIT9531X_PAGE_OUTSYS1;
+ else
+ page = SIT9531X_PAGE_OUTSYS0;
+ base_reg = clkout_odr_divn_base[slot % 6];
+
+ for (j = 4; j >= 0; j--) {
+ rc = sit9531x_read_u8(sitdev,
+ SIT9531X_REG(page, base_reg - j), &v);
+ if (rc)
+ return rc;
+ if (j == 4)
+ v &= 0x03;
+ divo = (divo << 8) | v;
+ }
+
+ if (!divo)
+ return -ENODEV;
+
+ *frequency = div64_u64(fvco, divo);
+ sitdev->out[out_idx].freq = (u32)*frequency;
+
+ return 0;
+}
+
+/*
+ * Phase adjust (PRG_RST_DELAY register-based).
+ *
+ * The chip exposes a per-output 34-bit coarse delay measured in VCO
+ * clock periods plus a 3-bit fine delay in fixed 30 ps steps. The
+ * five bytes PROG6..PROG2 hold the field across registers:
+ * base + 0 PROG6 [7:5] OPSTG_VCASC_BUMP (preserved via RMW)
+ * [4:2] PRG_RST_FINE_DELAY
+ * [1:0] PRG_RST_DELAY[33:32]
+ * base + 1 PROG5 PRG_RST_DELAY[31:24]
+ * base + 2 PROG4 PRG_RST_DELAY[23:16]
+ * base + 3 PROG3 PRG_RST_DELAY[15:8]
+ * base + 4 PROG2 PRG_RST_DELAY[7:0]
+ *
+ * Outputs 0-5 live on Page 3, outputs 6-11 on Page 4, with each
+ * output's block at base = 0x15 + 16 * (out_idx % 6).
+ *
+ * The chip only supports unsigned positive delay. A negative phase
+ * adjustment (advance) is wrapped to (T_out - |phase|) modulo one
+ * output period, which is identical for a periodic signal.
+ */
+
+int sit9531x_output_phase_adjust_set(struct sit9531x_dev *sitdev,
+ u8 out_idx, s32 phase_ps)
+{
+ const struct sit9531x_chip_info *info = sitdev->info;
+ u64 abs_ps, fvco, coarse, coarse_ps, rem_ps;
+ u8 page, base, prog6_val, fine = 0;
+ u8 pll_idx, slot;
+ u32 freq;
+ int rc, ret;
+
+ if (out_idx >= info->num_outputs)
+ return -EINVAL;
+
+ pll_idx = sitdev->out[out_idx].pll_idx;
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ freq = sitdev->out[out_idx].freq;
+ if (!freq)
+ return -EINVAL;
+
+ fvco = sit9531x_get_fvco(sitdev, pll_idx);
+ if (!fvco)
+ return -EIO;
+
+ /*
+ * Convert to unsigned absolute delay. Negative phase (advance)
+ * is rendered as T_out - |phase|, modulo the output period.
+ */
+ if (phase_ps == 0) {
+ abs_ps = 0;
+ } else if (phase_ps > 0) {
+ abs_ps = (u64)phase_ps;
+ } else {
+ u64 t_out_ps = div64_u64(1000000000000ULL, freq);
+ u64 advance = (u64)(-(s64)phase_ps);
+
+ if (t_out_ps == 0)
+ return -EINVAL;
+ advance %= t_out_ps;
+ abs_ps = (advance == 0) ? 0 : (t_out_ps - advance);
+ }
+
+ /*
+ * coarse_cycles = abs_ps * Fvco / 1e12 ps/s.
+ * mul_u64_u64_div_u64() avoids overflow when abs_ps approaches
+ * one second of 1 PPS wrap-around.
+ */
+ coarse = mul_u64_u64_div_u64(abs_ps, fvco, 1000000000000ULL);
+ if (coarse >= (1ULL << SIT9531X_OUT_PRG_COARSE_BITS))
+ return -ERANGE;
+
+ /* Fine delay = round((abs_ps - coarse * vco_period_ps) / 30 ps) */
+ coarse_ps = mul_u64_u64_div_u64(coarse, 1000000000000ULL, fvco);
+ rem_ps = (abs_ps > coarse_ps) ? (abs_ps - coarse_ps) : 0;
+ if (rem_ps) {
+ u64 steps;
+
+ steps = div64_u64(rem_ps + SIT9531X_OUT_PRG_FINE_STEP_PS / 2,
+ SIT9531X_OUT_PRG_FINE_STEP_PS);
+ if (steps > SIT9531X_OUT_PRG_FINE_MAX)
+ steps = SIT9531X_OUT_PRG_FINE_MAX;
+ fine = (u8)steps;
+ }
+
+ /*
+ * Map logical output index to the chip's physical output slot.
+ * On SiT95317 the eight logical outputs land on chip slots
+ * {0, 3, 4, 5, 7, 8, 9, 11}; on SiT95316 the map is identity.
+ * Page/base must address the slot, not the logical index.
+ */
+ slot = info->clkout_map[out_idx];
+ page = (slot > SIT9531X_PAGE_OUTSYS0_SLOT_MAX) ?
+ SIT9531X_PAGE_OUTSYS1 : SIT9531X_PAGE_OUTSYS0;
+ base = SIT9531X_OUT_PRG_DELAY_BASE +
+ SIT9531X_OUT_PRG_SLOT_STRIDE * (slot % 6);
+
+ /* Caller (dpll.c) holds multiop_lock around the whole sequence. */
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ /*
+ * The PRG_RST_DELAY bytes live in the output system, so the writes
+ * only take effect when made inside the PRG_CMD programming state and
+ * committed to the NVM shadow, exactly like sit9531x_output_freq_set().
+ */
+ rc = sit9531x_prg_enter(sitdev);
+ if (rc)
+ return rc;
+
+ /* PROG6 RMW: preserve OPSTG_VCASC_BUMP in [7:5] */
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG(page, base),
+ &prog6_val);
+ if (rc)
+ goto commit;
+
+ prog6_val &= SIT9531X_OUT_PRG_OPSTG_MASK;
+ prog6_val |= (fine << SIT9531X_OUT_PRG_FINE_SHIFT) &
+ SIT9531X_OUT_PRG_FINE_MASK;
+ prog6_val |= (u8)((coarse >> 32) & SIT9531X_OUT_PRG_COARSE_HI_MASK);
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(page, base),
+ prog6_val);
+ if (rc)
+ goto commit;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(page, base + 1),
+ (u8)((coarse >> 24) & 0xFF));
+ if (rc)
+ goto commit;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(page, base + 2),
+ (u8)((coarse >> 16) & 0xFF));
+ if (rc)
+ goto commit;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(page, base + 3),
+ (u8)((coarse >> 8) & 0xFF));
+ if (rc)
+ goto commit;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(page, base + 4),
+ (u8)(coarse & 0xFF));
+
+commit:
+ /*
+ * Always leave the PRG_CMD state via prg_commit(), even on a
+ * mid-sequence write failure, so the output loops are re-locked rather
+ * than stranded unlocked; keep the first error.
+ */
+ ret = sit9531x_prg_commit(sitdev);
+ if (ret && !rc)
+ rc = ret;
+ if (rc)
+ return rc;
+
+ /*
+ * Restart the output divider phase so the freshly programmed delay is
+ * applied against a known edge instead of the divider's arbitrary
+ * running phase.
+ */
+ return sit9531x_output_phase_flush(sitdev, pll_idx);
+}
+
+/*
+ * sit9531x_clear_notifications - clear all notification registers
+ *
+ * Clears all write-1-to-clear notification registers:
+ * - PLL outer LOL notification (Page 0, reg 0x07)
+ * - PLL holdover freeze notification (Page 0, reg 0x0B)
+ * - PLL inner LOL notification (Page 0, reg 0x93)
+ * - Clock monitor XO/PLL notification (Page 0, reg 0x9E)
+ * - Clock input notifications (Page 6, regs 0x03/0x07/0x93/0x97)
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_clear_notifications(struct sit9531x_dev *sitdev)
+{
+ int rc;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ /* Page 0x00 W1C notification registers */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_OUTER_LOL_NOTIF, 0xFF);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_HO_FREEZE_NOTIF, 0xFF);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_PLL_INNER_LOL_NOTIF, 0xFF);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_CMON_NOTIF, 0xFF);
+ if (rc)
+ return rc;
+
+ /* Page 0x06 clock input monitor notifications */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_CLKMON_P_NOTIF_01, 0xFF);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_CLKMON_P_NOTIF_23, 0xFF);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_CLKMON_N_NOTIF_01, 0xFF);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_CLKMON_N_NOTIF_23, 0xFF);
+ if (rc)
+ return rc;
+
+ dev_dbg(sitdev->dev, "All notification registers cleared\n");
+ return 0;
+}
+
+/*
+ * INTSYNC configuration register values.
+ * These are written to the source PLL's EXT page to enable/disable
+ * inter-PLL synchronization (lock frequency PLL to phase PLL).
+ */
+struct sit9531x_intsync_reg {
+ u8 offset;
+ u8 en_val;
+ u8 dis_val;
+};
+
+static const struct sit9531x_intsync_reg intsync_config[] = {
+ { 0x2D, 0x02, 0x00 },
+ { 0x50, 0x08, 0x00 },
+ { 0x51, 0x04, 0x00 },
+ { 0x54, 0x02, 0x00 },
+ { 0x55, 0x28, 0x20 },
+ { 0x5C, 0x0F, 0x00 },
+ { 0x5D, 0xFF, 0x00 },
+ { 0x6C, 0xDD, 0x00 },
+};
+
+/*
+ * sit9531x_intsync_enable - enable inter-PLL synchronization
+ * @src_pll_idx: source (frequency) PLL index (0-3)
+ *
+ * Enables INTSYNC global bit, unlocks the source PLL's EXT page
+ * debug registers, writes configuration, and triggers a small
+ * update on the source PLL.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_intsync_enable(struct sit9531x_dev *sitdev, u8 src_pll_idx)
+{
+ u8 ext_page, val;
+ int rc, i;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (src_pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ ext_page = SIT9531X_PLL_EXT_PAGE(src_pll_idx);
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_INTSYNC_GLOBAL, &val);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_INTSYNC_GLOBAL,
+ val | BIT(SIT9531X_INTSYNC_EN_BIT));
+ if (rc)
+ return rc;
+
+ /* Small update on Page 0 */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_GLOBAL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc)
+ return rc;
+
+ /* Unlock debug on EXT page */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(ext_page, SIT9531X_PLL_REG_DEBUG),
+ SIT9531X_PLL_DEBUG_UNLOCK);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < ARRAY_SIZE(intsync_config); i++) {
+ rc = sit9531x_write_u8(sitdev,
+ SIT9531X_REG(ext_page,
+ intsync_config[i].offset),
+ intsync_config[i].en_val);
+ if (rc)
+ return rc;
+ }
+
+ /* Small update on source PLL */
+ rc = sit9531x_write_pll_u8(sitdev, src_pll_idx,
+ SIT9531X_PLL_REG_SMALL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+/*
+ * sit9531x_intsync_disable - disable inter-PLL synchronization
+ * @src_pll_idx: source (frequency) PLL index (0-3)
+ *
+ * Clears INTSYNC global bit, writes disable values to the source
+ * PLL's EXT page, and triggers a small update.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_intsync_disable(struct sit9531x_dev *sitdev, u8 src_pll_idx)
+{
+ u8 ext_page, val;
+ int rc, i;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (src_pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ ext_page = SIT9531X_PLL_EXT_PAGE(src_pll_idx);
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_INTSYNC_GLOBAL, &val);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_INTSYNC_GLOBAL,
+ val & ~BIT(SIT9531X_INTSYNC_EN_BIT));
+ if (rc)
+ return rc;
+
+ /* Small update on Page 0 */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG_GLOBAL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc)
+ return rc;
+
+ /* Unlock debug on EXT page */
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(ext_page, SIT9531X_PLL_REG_DEBUG),
+ SIT9531X_PLL_DEBUG_UNLOCK);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < ARRAY_SIZE(intsync_config); i++) {
+ rc = sit9531x_write_u8(sitdev,
+ SIT9531X_REG(ext_page,
+ intsync_config[i].offset),
+ intsync_config[i].dis_val);
+ if (rc)
+ return rc;
+ }
+
+ /* Small update on source PLL */
+ rc = sit9531x_write_pll_u8(sitdev, src_pll_idx,
+ SIT9531X_PLL_REG_SMALL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+/*
+ * sit9531x_output_pulse_ctrl_set - program per-output PULSE_CTRL byte
+ * @out_idx: logical output index (translated to chip slot internally)
+ * @pulse_ctrl: 8-bit PULSE_CTRL value (PROG0)
+ *
+ * Writes ODRn_PROG0 on the output page (Page 3 for slots 0..5,
+ * Page 4 for slots 6..11) at offset 0x1B + 16 * (slot % 6).
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_output_pulse_ctrl_set(struct sit9531x_dev *sitdev,
+ u8 out_idx, u8 pulse_ctrl)
+{
+ const struct sit9531x_chip_info *info = sitdev->info;
+ u8 slot, page, reg;
+ int rc, ret;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (out_idx >= info->num_outputs)
+ return -EINVAL;
+
+ slot = info->clkout_map[out_idx];
+ page = (slot > SIT9531X_PAGE_OUTSYS0_SLOT_MAX) ?
+ SIT9531X_PAGE_OUTSYS1 : SIT9531X_PAGE_OUTSYS0;
+ reg = SIT9531X_OUT_PROG0_BASE +
+ SIT9531X_OUT_PRG_SLOT_STRIDE * (slot % 6);
+
+ /*
+ * PROG0 lives in the output system, so like the DIVO and
+ * PRG_RST_DELAY writes it only takes effect inside the PRG_CMD
+ * programming state committed to the NVM shadow.
+ */
+ rc = sit9531x_prg_enter(sitdev);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_write_u8(sitdev, SIT9531X_REG(page, reg), pulse_ctrl);
+
+ /*
+ * Always leave the PRG_CMD state via prg_commit(), even if the write
+ * failed, so the output loops are re-locked rather than stranded
+ * unlocked; keep the first error.
+ */
+ ret = sit9531x_prg_commit(sitdev);
+ if (ret && !rc)
+ rc = ret;
+
+ return rc;
+}
+
+/* Retries (at 1 s each) to wait for a PLL to reach its active state. */
+#define SIT9531X_PLL_ACTIVE_RETRIES 90
+
+/*
+ * sit9531x_phase_offset_read - read phase difference via TDC
+ * @phase_ps: output phase difference in picoseconds
+ *
+ * Reads the Time-to-Digital Converter (TDC) 40-bit code from the
+ * PLL page registers, then converts to picoseconds using the VCO
+ * frequency: phase_diff = tdc_code / fvco.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+int sit9531x_phase_offset_read(struct sit9531x_dev *sitdev, u8 pll_idx,
+ s64 *phase_ps)
+{
+ u64 fvco, fvco_mhz;
+ s64 tdc_signed;
+ u64 tdc_raw;
+ int rc, i;
+ bool sign;
+ u8 v;
+
+ lockdep_assert_held(&sitdev->multiop_lock);
+
+ if (pll_idx >= SIT9531X_NUM_PLLS)
+ return -EINVAL;
+
+ /* Unlock the debug page so the TDC registers are accessible. */
+ rc = sit9531x_write_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DEBUG,
+ SIT9531X_PLL_DEBUG_UNLOCK);
+ if (rc)
+ return rc;
+
+ /*
+ * Select the debug clock for taps below 200 kHz, then point the
+ * readback at the TDC. Only the one bit is touched: writing the
+ * modifier register whole would clear the fields belonging to
+ * other taps.
+ */
+ rc = sit9531x_update_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_WRITE_CODE,
+ SIT9531X_DBG_LOW_FREQ_CLK_BIT,
+ SIT9531X_DBG_LOW_FREQ_CLK_BIT);
+ if (rc)
+ return rc;
+ rc = sit9531x_write_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_READ_CODE,
+ SIT9531X_DBG_READ_CODE_TDC);
+ if (rc)
+ return rc;
+
+ /* Latch a sample by reading the trigger register 3 times. */
+ for (i = 0; i < 3; i++) {
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_TRIGGER, &v);
+ if (rc)
+ return rc;
+ }
+
+ tdc_raw = 0;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_DATA_4, &v);
+ if (rc)
+ return rc;
+ sign = !!(v & BIT(SIT9531X_TDC_SIGN_BIT));
+ tdc_raw = (u64)(v & 0x07) << 32;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_DATA_3, &v);
+ if (rc)
+ return rc;
+ tdc_raw |= (u64)v << 24;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_DATA_2, &v);
+ if (rc)
+ return rc;
+ tdc_raw |= (u64)v << 16;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_DATA_1, &v);
+ if (rc)
+ return rc;
+ tdc_raw |= (u64)v << 8;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_DBG_DATA_0, &v);
+ if (rc)
+ return rc;
+ tdc_raw |= v;
+
+ /*
+ * Apply sign. Per the vendor reference the sign bit is active-high
+ * for a positive offset: bit set -> +code, bit clear -> -code.
+ */
+ tdc_signed = sign ? (s64)tdc_raw : -(s64)tdc_raw;
+
+ /*
+ * Get VCO frequency for conversion. Fvco==0 means DIVN is not
+ * programmed (PLL unused on this board) -- skip silently rather
+ * than spamming the log on every poll cycle.
+ */
+ fvco = sit9531x_get_fvco(sitdev, pll_idx);
+ if (!fvco) {
+ dev_dbg(sitdev->dev, "PLL%c: Fvco unknown, skip TDC\n",
+ 'A' + pll_idx);
+ return -ENODEV;
+ }
+
+ /*
+ * phase_diff (seconds) = tdc_code / fvco
+ * phase_diff (ps) = tdc_code * 1e12 / fvco
+ *
+ * To avoid 64-bit overflow:
+ * phase_ps = tdc_code * 1e6 / (fvco / 1e6)
+ */
+ fvco_mhz = div64_u64(fvco, 1000000ULL);
+ if (!fvco_mhz)
+ return -EIO;
+
+ *phase_ps = div64_s64(tdc_signed * 1000000LL, (s64)fvco_mhz);
+
+ return 0;
+}
+
+/*
+ * sit9531x_ref_state_fetch - read input reference status from hardware
+ * @index: logical input index
+ *
+ * Reads LOS and OOF status for the given input lane from the Page 0x06
+ * clock monitor registers. P and N lanes have separate register banks;
+ * each register carries two input pairs nibble-packed (even pair in
+ * bits [3:0], odd pair in [7:4]).
+ */
+static int sit9531x_ref_state_fetch(struct sit9531x_dev *sitdev, u8 index)
+{
+ unsigned int reg, force_reg, state_reg;
+ u8 pair, status, force, state;
+ struct sit9531x_ref *ref;
+ int rc;
+
+ /*
+ * The XTAL/XO reference (index SIT9531X_MAX_INPUTS) is the on-chip
+ * oscillator that feeds every PLL. It cannot be routed or deselected,
+ * so its pin is modelled as permanently connected (see
+ * sit9531x_dpll_xo_pin_ops) and its LOS/OOF flags are never consulted.
+ * Only the routable per-lane inputs (0..num_inputs-1) are polled here.
+ */
+ if (index >= SIT9531X_MAX_INPUTS)
+ return -EINVAL;
+
+ ref = &sitdev->ref[index];
+ pair = sit9531x_input_pair(index);
+
+ if (sit9531x_input_is_n(index))
+ reg = pair < 2 ? SIT9531X_CLKMON_N_STATUS_01
+ : SIT9531X_CLKMON_N_STATUS_23;
+ else
+ reg = pair < 2 ? SIT9531X_CLKMON_P_STATUS_01
+ : SIT9531X_CLKMON_P_STATUS_23;
+
+ rc = sit9531x_read_u8(sitdev, reg, &status);
+ if (rc)
+ return rc;
+
+ if (pair & 1)
+ status >>= 4;
+
+ ref->los = !!(status & (BIT(SIT9531X_CLKMON_CLK_LOSS) |
+ BIT(SIT9531X_CLKMON_CLK_LOSS_FD)));
+ ref->oof = !!(status & (BIT(SIT9531X_CLKMON_FREQ_FINE) |
+ BIT(SIT9531X_CLKMON_FREQ_COARSE)));
+
+ /*
+ * Whether the receiver is on. This has to come from the chip: it
+ * is the loaded configuration that decides, and without reading it
+ * back every input would look disabled until something called
+ * sit9531x_input_enable(). A lane counts as disabled only while
+ * the force bit overrides it to the off state; with the force bit
+ * clear it follows the configuration, which is the enabled case.
+ */
+ sit9531x_input_get_regs(sitdev, index, &force_reg, &state_reg);
+
+ rc = sit9531x_read_u8(sitdev, force_reg, &force);
+ if (rc)
+ return rc;
+ rc = sit9531x_read_u8(sitdev, state_reg, &state);
+ if (rc)
+ return rc;
+
+ ref->enabled = !((force & BIT(pair)) && !(state & BIT(pair)));
+
+ return 0;
+}
+
+/*
+ * sit9531x_input_mode_fetch - detect SE/DE configuration of an input pair
+ * @pair: input pair number (0-3)
+ *
+ * Reads CLKINx_INPUT_MODE and stores the detected signal mode on both
+ * lanes of the pair. A pair with neither SE lane enabled is running
+ * differential.
+ */
+static int sit9531x_input_mode_fetch(struct sit9531x_dev *sitdev, u8 pair)
+{
+ enum sit9531x_signal_mode sig_mode;
+ u8 mode;
+ int rc;
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_IN_MODE(pair), &mode);
+ if (rc)
+ return rc;
+
+ if (mode & (SIT9531X_IN_MODE_SE_P_EN | SIT9531X_IN_MODE_SE_N_EN))
+ sig_mode = SIT9531X_MODE_SE;
+ else
+ sig_mode = SIT9531X_MODE_DE;
+
+ sitdev->ref[pair * 2].sig_mode = sig_mode;
+ sitdev->ref[pair * 2 + 1].sig_mode = sig_mode;
+
+ dev_dbg(sitdev->dev, "CLKIN%u mode reg 0x%02x -> %s\n", pair, mode,
+ sig_mode == SIT9531X_MODE_DE ? "differential" : "single-ended");
+
+ return 0;
+}
+
+/*
+ * sit9531x_chan_state_fetch - read PLL channel status from hardware
+ *
+ * Reads lock status and mode from the PLL status register.
+ */
+/* Read the PLL active-state bit (PLL page reg 0x02 bit 0). */
+static int sit9531x_pll_is_active(struct sit9531x_dev *sitdev, u8 pll_idx,
+ bool *active)
+{
+ u8 v;
+ int rc;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx, SIT9531X_PLL_REG_ACTIVE, &v);
+ if (rc)
+ return rc;
+
+ *active = !!(v & SIT9531X_PLL_ACTIVE_BIT);
+
+ return 0;
+}
+
+static int sit9531x_chan_state_fetch(struct sit9531x_dev *sitdev, u8 pll_idx)
+{
+ u8 status, outer_lol, input_sel, inner_lol, ho_freeze, activesel_reg;
+ struct sit9531x_chan *chan = &sitdev->chan[pll_idx];
+ bool active;
+ int rc;
+
+ /*
+ * Whether the PLL is running at all. The loss-of-lock bit read
+ * below is driven by the PLL itself, so on one the loaded
+ * configuration leaves unused it simply stays clear and would
+ * otherwise read as a lock.
+ */
+ rc = sit9531x_pll_is_active(sitdev, pll_idx, &active);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_STATUS, &status);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_OUTER_LOL_STATUS,
+ &outer_lol);
+ if (rc)
+ return rc;
+
+ /*
+ * Read the input source the PLL has currently selected as its
+ * active reference. This lives in the low nibble of the last
+ * register of the PLL's page-1 priority block (CLK_ACTIVESEL_PLL),
+ * not on the PLL page -- PLL-page 0x29 is a config register.
+ */
+ activesel_reg = SIT9531X_PRIO_BASE_REG +
+ SIT9531X_PRIO_REGS_PER_PLL * pll_idx +
+ SIT9531X_PRIO_ACTIVESEL_OFF;
+ rc = sit9531x_read_u8(sitdev,
+ SIT9531X_REG(SIT9531X_PAGE_PRIOSYS,
+ activesel_reg),
+ &input_sel);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_PLL_INNER_LOL_STATUS,
+ &inner_lol);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_read_u8(sitdev, SIT9531X_REG_HO_FREEZE_STATUS, &ho_freeze);
+ if (rc)
+ return rc;
+
+ /* STATUS_1_GENERIC reports loss of lock, so invert it. */
+ chan->active = active;
+ chan->locked = active && !(outer_lol & BIT(pll_idx));
+ chan->mode = !!(status & SIT9531X_PLL_STATUS_OUTER_DIS);
+ chan->selected_ref =
+ sit9531x_hw_src_input(input_sel & SIT9531X_PRIO_NIBBLE_MASK);
+ chan->inner_lol = !!(inner_lol & BIT(pll_idx));
+ chan->ho_freeze = !!(ho_freeze & BIT(pll_idx));
+
+ return 0;
+}
+
+/*
+ * sit9531x_out_state_fetch - read output status from hardware
+ *
+ * Reads the output PLL association from the PLL page output map
+ * registers into out->routed / out->pll_idx, and the current drive
+ * state from the Hi-Z force bits into out->enabled. The two are
+ * separate: routing decides whether the output gets a DPLL pin at all,
+ * while a muted but routed output keeps its pin and reports
+ * DPLL_PIN_STATE_DISCONNECTED until it is un-muted.
+ */
+static int sit9531x_out_state_fetch(struct sit9531x_dev *sitdev, u8 index)
+{
+ struct sit9531x_out *out = &sitdev->out[index];
+ u8 map_lo, map_hi, slot;
+ int pll_idx;
+ bool muted;
+ int rc;
+
+ slot = sitdev->info->clkout_map[index];
+
+ rc = sit9531x_output_forced_hiz(sitdev, slot, &muted);
+ if (rc)
+ return rc;
+
+ /*
+ * DT board-config override: the per-PLL OUTPUT_ENABLE bitmaps
+ * (0x27/0x28) do not unambiguously express output->PLL routing on
+ * every config (overlaps, and some outputs routed outside that
+ * path). When the board supplies an explicit map, trust it.
+ */
+ if (sitdev->out_pll_map_valid) {
+ u8 m = sitdev->out_pll_map[index];
+
+ if (m < SIT9531X_NUM_PLLS) {
+ out->pll_idx = m;
+ out->routed = true;
+ out->enabled = !muted;
+ } else {
+ out->pll_idx = 0;
+ out->routed = false;
+ out->enabled = false;
+ }
+ return 0;
+ }
+
+ /*
+ * The OUT_MAP_LO/HI bitmaps are indexed by the physical slot the
+ * output occupies on the chip, not by the driver's logical output
+ * index (translated above via the chip-info clkout_map[]: identity
+ * on SiT95316, non-contiguous on SiT95317).
+ *
+ * Determine which PLL drives this output by checking each PLL's
+ * output map registers (0x27 = slots 8-11, 0x28 = slots 0-7).
+ */
+ for (pll_idx = 0; pll_idx < SIT9531X_NUM_PLLS; pll_idx++) {
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_OUT_MAP_LO, &map_lo);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_read_pll_u8(sitdev, pll_idx,
+ SIT9531X_PLL_REG_OUT_MAP_HI, &map_hi);
+ if (rc)
+ return rc;
+
+ if (slot < 8) {
+ if (map_lo & BIT(slot)) {
+ out->pll_idx = pll_idx;
+ out->routed = true;
+ out->enabled = !muted;
+ return 0;
+ }
+ } else {
+ if (map_hi & BIT(slot - 8)) {
+ out->pll_idx = pll_idx;
+ out->routed = true;
+ out->enabled = !muted;
+ return 0;
+ }
+ }
+ }
+
+ /* Output not mapped to any PLL */
+ out->pll_idx = 0;
+ out->routed = false;
+ out->enabled = false;
+
+ return 0;
+}
+
+/*
+ * sit9531x_ref_pll_mask_fetch - seed the input-to-PLL usage masks
+ *
+ * ref->pll_mask is the refcount the disconnect path uses to decide when
+ * an input receiver may be powered down: the physical input is only
+ * disabled once the last DPLL has released it. It therefore has to
+ * start out matching the hardware. Without this pass every mask starts
+ * at zero, and disconnecting an input from one DPLL drops the mask to
+ * zero and disables a receiver the other DPLLs are still locked to.
+ *
+ * An input is counted for a PLL when it appears in that PLL's Page-1
+ * priority table, which is exactly the condition the connect and
+ * disconnect callbacks maintain. Sources that are not physical inputs
+ * (OCXO, INTSYNC) and reserved codes are skipped.
+ *
+ * Caller must hold sitdev->multiop_lock.
+ */
+static int sit9531x_ref_pll_mask_fetch(struct sit9531x_dev *sitdev)
+{
+ u8 srcs[SIT9531X_PRIO_MAX_SLOTS];
+ u8 pll_idx, slot, index;
+ int rc;
+
+ for (pll_idx = 0; pll_idx < SIT9531X_NUM_PLLS; pll_idx++) {
+ rc = sit9531x_prio_table_read(sitdev, pll_idx, srcs);
+ if (rc)
+ return rc;
+
+ for (slot = 0; slot < SIT9531X_PRIO_MAX_SLOTS; slot++) {
+ index = sit9531x_hw_src_input(srcs[slot]);
+ if (index >= sitdev->info->num_inputs)
+ continue;
+
+ /*
+ * On a differentially configured pair only the P lane
+ * has a DPLL pin, so that is the lane the connect and
+ * disconnect callbacks account for. Fold an N-lane
+ * table entry onto its P lane, otherwise the count
+ * would land on a lane nothing ever releases. The
+ * signalling mode is already known here:
+ * sit9531x_input_mode_fetch() runs first.
+ */
+ if (sit9531x_input_is_n(index) &&
+ sitdev->ref[index].sig_mode == SIT9531X_MODE_DE)
+ index--;
+
+ sitdev->ref[index].pll_mask |= BIT(pll_idx);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * sit9531x_dev_state_fetch - read all hardware state at startup
+ *
+ * Called once during probe to populate the initial state cache.
+ */
+static int sit9531x_dev_state_fetch(struct sit9531x_dev *sitdev)
+{
+ int rc;
+ u8 i;
+
+ /* Detect SE/DE configuration before any per-lane access */
+ for (i = 0; i < sitdev->info->num_inputs / 2; i++) {
+ rc = sit9531x_input_mode_fetch(sitdev, i);
+ if (rc) {
+ dev_err(sitdev->dev,
+ "Failed to fetch CLKIN%u mode: %d\n", i, rc);
+ return rc;
+ }
+ }
+
+ for (i = 0; i < sitdev->info->num_inputs; i++) {
+ rc = sit9531x_ref_state_fetch(sitdev, i);
+ if (rc) {
+ dev_err(sitdev->dev,
+ "Failed to fetch input %u state: %d\n", i, rc);
+ return rc;
+ }
+ }
+
+ /*
+ * The priority-table read walks the Page-1 registers, so it runs
+ * with multiop_lock held like every other multi-register sequence.
+ * Nothing can race with it here -- the DPLLs are not registered and
+ * the monitor is not running yet -- but the page handling stays
+ * serialized the same way as at runtime.
+ */
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_ref_pll_mask_fetch(sitdev);
+ mutex_unlock(&sitdev->multiop_lock);
+ if (rc) {
+ dev_err(sitdev->dev,
+ "Failed to fetch input priority tables: %d\n", rc);
+ return rc;
+ }
+
+ for (i = 0; i < sitdev->info->num_outputs; i++) {
+ rc = sit9531x_out_state_fetch(sitdev, i);
+ if (rc) {
+ dev_err(sitdev->dev,
+ "Failed to fetch output %u state: %d\n", i, rc);
+ return rc;
+ }
+ }
+
+ for (i = 0; i < SIT9531X_NUM_PLLS; i++) {
+ rc = sit9531x_chan_state_fetch(sitdev, i);
+ if (rc) {
+ dev_err(sitdev->dev,
+ "Failed to fetch PLL%c state: %d\n",
+ 'A' + i, rc);
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+static void sit9531x_dev_ref_states_update(struct sit9531x_dev *sitdev)
+{
+ int i, rc;
+
+ for (i = 0; i < sitdev->info->num_inputs; i++) {
+ rc = sit9531x_ref_state_fetch(sitdev, i);
+ if (rc)
+ dev_warn(sitdev->dev,
+ "Failed to get REF%u status: %d\n", i, rc);
+ }
+}
+
+static void sit9531x_dev_chan_states_update(struct sit9531x_dev *sitdev)
+{
+ int i, rc;
+
+ for (i = 0; i < SIT9531X_NUM_PLLS; i++) {
+ rc = sit9531x_chan_state_fetch(sitdev, i);
+ if (rc)
+ dev_warn(sitdev->dev,
+ "Failed to get PLL%c state: %d\n",
+ 'A' + i, rc);
+ }
+}
+
+/*
+ * sit9531x_dev_periodic_work - periodic hardware state polling
+ * @work: kthread_work pointer
+ *
+ * Polls hardware state at SIT9531X_STATUS_POLL_MS intervals.
+ * Updates reference and channel states, then delegates change
+ * detection to sit9531x_dpll_changes_check() for each registered DPLL.
+ */
+static void sit9531x_dev_periodic_work(struct kthread_work *work)
+{
+ struct sit9531x_dev *sitdev = container_of(work, struct sit9531x_dev,
+ work.work);
+ struct sit9531x_dpll *sitdpll;
+ int rc;
+
+ /*
+ * Update the cached ref[]/chan[] arrays under multiop_lock so the
+ * fetches are serialized against the DPLL callbacks that read
+ * these fields and against the chip's page selector.
+ *
+ * The lock is then dropped before sit9531x_dpll_changes_check(),
+ * which calls dpll_pin_change_ntf() / dpll_device_change_ntf().
+ * Those notification helpers take DPLL-subsystem locks that are
+ * already held when our callbacks are invoked from netlink
+ * context, and nesting multiop_lock around them would invert the
+ * lock order. changes_check() reads the cache published above,
+ * which is already consistent.
+ */
+ mutex_lock(&sitdev->multiop_lock);
+ sit9531x_dev_ref_states_update(sitdev);
+ sit9531x_dev_chan_states_update(sitdev);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ list_for_each_entry(sitdpll, &sitdev->dplls, list)
+ sit9531x_dpll_changes_check(sitdpll);
+
+ /*
+ * Acknowledge the chip's notification latches after the tick has
+ * read and acted on them. Without this, the W1C bits remain set
+ * and -- on boards that wire INTRB -- the line stays asserted,
+ * re-firing the threaded handler back to back. The helper writes
+ * W1C bits across page 0 and page 6 and must run under
+ * multiop_lock to serialize the page selector against userspace
+ * dpll ops. Failure is non-fatal: status was already consumed
+ * for this tick and the next tick re-processes whatever stayed
+ * latched.
+ */
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_clear_notifications(sitdev);
+ mutex_unlock(&sitdev->multiop_lock);
+ if (rc)
+ dev_warn_ratelimited(sitdev->dev,
+ "Failed to clear notifications: %d\n",
+ rc);
+
+ /* Run twice a second */
+ kthread_queue_delayed_work(sitdev->kworker, &sitdev->work,
+ msecs_to_jiffies(SIT9531X_STATUS_POLL_MS));
+}
+
+/*
+ * sit9531x_irq_thread_fn - threaded IRQ handler for the chip's INTRB line
+ *
+ * Triggered when the chip asserts INTRB (and only when DT wires up the
+ * client interrupt; absent property == handler never installed). The
+ * action mirrors a periodic-work tick: queue an immediate run so status
+ * registers are read and DPLL changes_check fires without waiting for
+ * the next poll deadline. Polling continues to run as a fallback.
+ */
+static irqreturn_t sit9531x_irq_thread_fn(int irq, void *data)
+{
+ struct sit9531x_dev *sitdev = data;
+ int rc;
+
+ /*
+ * Acknowledge the chip's notification latches from the threaded
+ * handler itself. With IRQF_ONESHOT the line is unmasked on
+ * return, so deferring the W1C clear to the async kworker would
+ * let a still-asserted INTRB re-fire immediately (interrupt storm).
+ * Clear here, then kick the poll worker to read state and run
+ * changes_check.
+ */
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_clear_notifications(sitdev);
+ mutex_unlock(&sitdev->multiop_lock);
+ if (rc)
+ dev_warn_ratelimited(sitdev->dev,
+ "IRQ: failed to clear notifications: %d\n",
+ rc);
+
+ kthread_mod_delayed_work(sitdev->kworker, &sitdev->work, 0);
+ return IRQ_HANDLED;
+}
+
+/*
+ * sit9531x_dev_start - start normal operation
+ *
+ * Fetches initial hardware state, registers all DPLL devices and
+ * their pins, and starts the periodic monitoring thread.
+ */
+int sit9531x_dev_start(struct sit9531x_dev *sitdev)
+{
+ struct sit9531x_dpll *sitdpll;
+ int rc;
+
+ /* Fetch device state */
+ rc = sit9531x_dev_state_fetch(sitdev);
+ if (rc)
+ return rc;
+
+ list_for_each_entry(sitdpll, &sitdev->dplls, list) {
+ rc = sit9531x_dpll_register(sitdpll);
+ if (rc) {
+ dev_err_probe(sitdev->dev, rc,
+ "Failed to register DPLL%u\n",
+ sitdpll->id);
+ goto err_unregister;
+ }
+ }
+
+ kthread_queue_delayed_work(sitdev->kworker, &sitdev->work, 0);
+
+ return 0;
+
+err_unregister:
+ /*
+ * Unregister what did register. The caller frees the list on this
+ * path, so leaving a DPLL registered would hand the subsystem a
+ * pointer to freed memory.
+ */
+ list_for_each_entry_continue_reverse(sitdpll, &sitdev->dplls, list)
+ sit9531x_dpll_unregister(sitdpll);
+
+ return rc;
+}
+
+/*
+ * sit9531x_dev_stop - stop normal operation
+ *
+ * Cancels the monitoring thread and unregisters all DPLL devices
+ * and their pins.
+ */
+void sit9531x_dev_stop(struct sit9531x_dev *sitdev)
+{
+ struct sit9531x_dpll *sitdpll;
+
+ kthread_cancel_delayed_work_sync(&sitdev->work);
+
+ list_for_each_entry(sitdpll, &sitdev->dplls, list) {
+ if (sitdpll->dpll_dev)
+ sit9531x_dpll_unregister(sitdpll);
+ }
+}
+
+static struct sit9531x_dpll_pin *
+sit9531x_dpll_pin_alloc(struct sit9531x_dpll *sitdpll,
+ enum dpll_pin_direction dir, u8 id)
+{
+ struct sit9531x_dpll_pin *pin;
+
+ pin = kzalloc_obj(*pin, GFP_KERNEL);
+ if (!pin)
+ return ERR_PTR(-ENOMEM);
+
+ pin->dpll = sitdpll;
+ pin->dir = dir;
+ pin->id = id;
+
+ return pin;
+}
+
+/*
+ * sit9531x_dpll_pin_register - register a DPLL pin with the subsystem
+ * @index: absolute pin index for clock_id namespace
+ *
+ * Gets pin properties from firmware, creates or gets a dpll_pin,
+ * and registers it with the parent DPLL device.
+ */
+static int sit9531x_dpll_pin_register(struct sit9531x_dpll_pin *pin,
+ u32 index)
+{
+ struct sit9531x_dpll *sitdpll = pin->dpll;
+ struct sit9531x_pin_props *props;
+ const struct dpll_pin_ops *ops;
+ int rc;
+
+ props = sit9531x_pin_props_get(sitdpll->dev, pin->dir, pin->id);
+ if (IS_ERR(props))
+ return PTR_ERR(props);
+
+ strscpy(pin->label, props->package_label, sizeof(pin->label));
+ pin->fwnode = fwnode_handle_get(props->fwnode);
+ pin->esync_control = props->esync_control;
+
+ pin->dpll_pin = dpll_pin_get(sitdpll->dev->clock_id, index,
+ THIS_MODULE, &props->dpll_props,
+ &pin->tracker);
+ if (IS_ERR(pin->dpll_pin)) {
+ rc = PTR_ERR(pin->dpll_pin);
+ goto err_pin_get;
+ }
+ dpll_pin_fwnode_set(pin->dpll_pin, props->fwnode);
+
+ ops = sit9531x_dpll_pin_ops_get(pin);
+
+ rc = dpll_pin_register(sitdpll->dpll_dev, pin->dpll_pin, ops, pin);
+ if (rc)
+ goto err_register;
+
+ sit9531x_pin_props_put(props);
+
+ return 0;
+
+err_register:
+ dpll_pin_put(pin->dpll_pin, &pin->tracker);
+err_pin_get:
+ /* dpll_pin_get() left an ERR_PTR here. */
+ pin->dpll_pin = NULL;
+ fwnode_handle_put(pin->fwnode);
+ pin->fwnode = NULL;
+ sit9531x_pin_props_put(props);
+
+ return rc;
+}
+
+static void sit9531x_dpll_pin_unregister(struct sit9531x_dpll_pin *pin)
+{
+ struct sit9531x_dpll *sitdpll = pin->dpll;
+ const struct dpll_pin_ops *ops;
+
+ ops = sit9531x_dpll_pin_ops_get(pin);
+
+ dpll_pin_unregister(sitdpll->dpll_dev, pin->dpll_pin, ops, pin);
+ dpll_pin_put(pin->dpll_pin, &pin->tracker);
+ pin->dpll_pin = NULL;
+
+ fwnode_handle_put(pin->fwnode);
+ pin->fwnode = NULL;
+}
+
+static void sit9531x_dpll_pins_unregister(struct sit9531x_dpll *sitdpll)
+{
+ struct sit9531x_dpll_pin *pin, *next;
+
+ list_for_each_entry_safe(pin, next, &sitdpll->pins, list) {
+ sit9531x_dpll_pin_unregister(pin);
+ list_del(&pin->list);
+ kfree(pin);
+ }
+}
+
+/*
+ * sit9531x_input_pin_is_registrable - check if an input pin is registrable
+ *
+ * Split out so input-model changes stay local to this helper.
+ *
+ * Return: true if the input pin should be registered, false otherwise
+ */
+static bool sit9531x_input_pin_is_registrable(struct sit9531x_dev *sitdev,
+ u8 index)
+{
+ if (index >= sitdev->info->num_inputs)
+ return false;
+
+ /*
+ * The N lane of a differentially-configured pair is not a
+ * standalone input and is skipped (zl3073x model).
+ */
+ if (sit9531x_input_is_n(index) &&
+ sitdev->ref[index].sig_mode == SIT9531X_MODE_DE)
+ return false;
+
+ return true;
+}
+
+/*
+ * sit9531x_dpll_pin_is_registrable - check if a pin should be registered
+ * @dir: pin direction
+ * @index: pin hardware index
+ *
+ * For input pins: delegate to sit9531x_input_pin_is_registrable().
+ * For output pins: the pin is registrable if this DPLL is routed to it,
+ * whether or not it is currently driving.
+ *
+ * Return: true if pin should be registered, false otherwise
+ */
+static bool sit9531x_dpll_pin_is_registrable(struct sit9531x_dpll *sitdpll,
+ enum dpll_pin_direction dir,
+ u8 index)
+{
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+
+ if (dir == DPLL_PIN_DIRECTION_INPUT) {
+ /* The internal INTSYNC and XO pins are always registrable */
+ if (index == SIT9531X_INTSYNC_PIN_ID ||
+ index == SIT9531X_MAX_INPUTS)
+ return true;
+
+ return sit9531x_input_pin_is_registrable(sitdev, index);
+ }
+
+ /* The internal INTSYNC source pin is always registrable */
+ if (index == SIT9531X_INTSYNC_OUT_PIN_ID)
+ return true;
+
+ /* Output -- check if driven by this DPLL */
+ if (index >= sitdev->info->num_outputs)
+ return false;
+
+ /*
+ * Routing, not the current drive state: an output the initial
+ * configuration muted still gets a pin, so userspace can see it and
+ * un-mute it. Only outputs no PLL drives are left unregistered.
+ */
+ return sitdev->out[index].pll_idx == sitdpll->id &&
+ sitdev->out[index].routed;
+}
+
+/*
+ * sit9531x_dpll_pins_register - register all registrable pins
+ *
+ * Enumerates all possible input and output pins, checks registrability,
+ * and registers each one. Input pins come first, then output pins,
+ * with input pins first, then output pins.
+ */
+static int sit9531x_dpll_pins_register(struct sit9531x_dpll *sitdpll)
+{
+ struct sit9531x_dpll_pin *pin;
+ enum dpll_pin_direction dir;
+ u8 id, index;
+ int rc;
+
+ for (index = 0; index < SIT9531X_NUM_PINS_TOTAL; index++) {
+ if (index < SIT9531X_NUM_INPUT_PINS) {
+ id = index;
+ dir = DPLL_PIN_DIRECTION_INPUT;
+ } else {
+ id = index - SIT9531X_NUM_INPUT_PINS;
+ dir = DPLL_PIN_DIRECTION_OUTPUT;
+ }
+
+ if (!sit9531x_dpll_pin_is_registrable(sitdpll, dir, id))
+ continue;
+
+ pin = sit9531x_dpll_pin_alloc(sitdpll, dir, id);
+ if (IS_ERR(pin)) {
+ rc = PTR_ERR(pin);
+ goto error;
+ }
+
+ rc = sit9531x_dpll_pin_register(pin, index);
+ if (rc) {
+ kfree(pin);
+ goto error;
+ }
+
+ list_add(&pin->list, &sitdpll->pins);
+ }
+
+ return 0;
+
+error:
+ sit9531x_dpll_pins_unregister(sitdpll);
+ return rc;
+}
+
+static int sit9531x_dpll_device_register(struct sit9531x_dpll *sitdpll)
+{
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc;
+
+ sitdpll->ops = sit9531x_dpll_device_ops;
+
+ sitdpll->dpll_dev = dpll_device_get(sitdev->clock_id, sitdpll->id,
+ THIS_MODULE, &sitdpll->tracker);
+ if (IS_ERR(sitdpll->dpll_dev)) {
+ rc = PTR_ERR(sitdpll->dpll_dev);
+ sitdpll->dpll_dev = NULL;
+ return rc;
+ }
+
+ rc = dpll_device_register(sitdpll->dpll_dev,
+ sit9531x_prop_dpll_type_get(sitdev,
+ sitdpll->id),
+ &sitdpll->ops, sitdpll);
+ if (rc) {
+ dpll_device_put(sitdpll->dpll_dev, &sitdpll->tracker);
+ sitdpll->dpll_dev = NULL;
+ }
+
+ return rc;
+}
+
+static void sit9531x_dpll_device_unregister(struct sit9531x_dpll *sitdpll)
+{
+ dpll_device_unregister(sitdpll->dpll_dev, &sitdpll->ops, sitdpll);
+ dpll_device_put(sitdpll->dpll_dev, &sitdpll->tracker);
+ sitdpll->dpll_dev = NULL;
+}
+
+/*
+ * sit9531x_dpll_alloc - allocate a DPLL device structure
+ * @sitdev: parent device
+ * @ch: PLL channel number (0-3)
+ *
+ * Return: pointer to allocated DPLL on success, error pointer on error
+ */
+struct sit9531x_dpll *sit9531x_dpll_alloc(struct sit9531x_dev *sitdev, u8 ch)
+{
+ struct sit9531x_dpll *sitdpll;
+
+ sitdpll = kzalloc_obj(*sitdpll, GFP_KERNEL);
+ if (!sitdpll)
+ return ERR_PTR(-ENOMEM);
+
+ sitdpll->dev = sitdev;
+ sitdpll->id = ch;
+ sitdpll->lock_status = DPLL_LOCK_STATUS_UNLOCKED;
+ INIT_LIST_HEAD(&sitdpll->pins);
+
+ return sitdpll;
+}
+
+/*
+ * sit9531x_dpll_free - deallocate a DPLL device structure
+ * @sitdpll: DPLL to free
+ */
+void sit9531x_dpll_free(struct sit9531x_dpll *sitdpll)
+{
+ kfree(sitdpll);
+}
+
+/*
+ * sit9531x_dpll_register - register DPLL device and all its pins
+ *
+ * Registers the DPLL device with the subsystem and then registers
+ * all input and output pins that are connected to this PLL.
+ */
+int sit9531x_dpll_register(struct sit9531x_dpll *sitdpll)
+{
+ int rc;
+
+ rc = sit9531x_dpll_device_register(sitdpll);
+ if (rc)
+ return rc;
+
+ rc = sit9531x_dpll_pins_register(sitdpll);
+ if (rc) {
+ sit9531x_dpll_device_unregister(sitdpll);
+ return rc;
+ }
+
+ return 0;
+}
+
+/* sit9531x_dpll_unregister - unregister DPLL device and its pins */
+void sit9531x_dpll_unregister(struct sit9531x_dpll *sitdpll)
+{
+ sit9531x_dpll_pins_unregister(sitdpll);
+ sit9531x_dpll_device_unregister(sitdpll);
+}
+
+static void sit9531x_dpll_list_free(struct sit9531x_dev *sitdev)
+{
+ struct sit9531x_dpll *sitdpll, *next;
+
+ list_for_each_entry_safe(sitdpll, next, &sitdev->dplls, list) {
+ list_del(&sitdpll->list);
+ sit9531x_dpll_free(sitdpll);
+ }
+}
+
+/* Runs only once the device is fully started, see the caller. */
+static void sit9531x_dev_dpll_fini(void *ptr)
+{
+ struct sit9531x_dev *sitdev = ptr;
+
+ sit9531x_dev_stop(sitdev);
+ kthread_destroy_worker(sitdev->kworker);
+ sit9531x_dpll_list_free(sitdev);
+}
+
+static int sit9531x_devm_dpll_init(struct sit9531x_dev *sitdev)
+{
+ struct kthread_worker *kworker;
+ struct sit9531x_dpll *sitdpll;
+ unsigned int i;
+ int rc;
+
+ INIT_LIST_HEAD(&sitdev->dplls);
+ kthread_init_delayed_work(&sitdev->work, sit9531x_dev_periodic_work);
+
+ for (i = 0; i < SIT9531X_NUM_PLLS; i++) {
+ sitdpll = sit9531x_dpll_alloc(sitdev, i);
+ if (IS_ERR(sitdpll)) {
+ rc = dev_err_probe(sitdev->dev, PTR_ERR(sitdpll),
+ "Failed to alloc DPLL%u\n", i);
+ goto err_free_dplls;
+ }
+
+ list_add_tail(&sitdpll->list, &sitdev->dplls);
+ }
+
+ kworker = kthread_run_worker(0, "sit9531x-%s", dev_name(sitdev->dev));
+ if (IS_ERR(kworker)) {
+ rc = PTR_ERR(kworker);
+ goto err_free_dplls;
+ }
+ sitdev->kworker = kworker;
+
+ rc = sit9531x_dev_start(sitdev);
+ if (rc) {
+ rc = dev_err_probe(sitdev->dev, rc, "Failed to start device\n");
+ goto err_destroy_worker;
+ }
+
+ /*
+ * Only now is every field the cleanup touches valid, so this is the
+ * first point at which the action may be registered. On failure it
+ * runs the action itself, which is correct here and only here.
+ */
+ return devm_add_action_or_reset(sitdev->dev, sit9531x_dev_dpll_fini,
+ sitdev);
+
+err_destroy_worker:
+ kthread_destroy_worker(sitdev->kworker);
+err_free_dplls:
+ sit9531x_dpll_list_free(sitdev);
+
+ return rc;
+}
+
+/*
+ * sit9531x_read_variant_id - read chip variant ID byte from hardware
+ * @id: output variant ID byte
+ *
+ * Reads the single-byte variant identification register from Page 0
+ * reg 0x02 (95317 = 0x17, 95316 = 0x31). Reg 0x03 holds a separate
+ * revision byte and is intentionally not consumed here.
+ */
+static int sit9531x_read_variant_id(struct sit9531x_dev *sitdev, u8 *id)
+{
+ return sit9531x_read_u8(sitdev, SIT9531X_REG_VARIANT_ID, id);
+}
+
+static const struct sit9531x_chip_info *sit9531x_match_variant(u8 id)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(sit9531x_chip_ids); i++) {
+ if (sit9531x_chip_ids[i].id == id)
+ return &sit9531x_chip_ids[i];
+ }
+
+ return NULL;
+}
+
+/*
+ * sit9531x_derive_clock_id - build EUI-64 clock identifier
+ *
+ * Generates a deterministic 64-bit identifier from the SiTime OUI,
+ * the chip ID, and the I2C address. This provides a stable clock_id
+ * across reboots.
+ *
+ * Return: 64-bit clock identifier
+ */
+static u64 sit9531x_derive_clock_id(struct sit9531x_dev *sitdev)
+{
+ u64 clkid;
+
+ clkid = SIT9531X_OUI << 24;
+ clkid |= (u64)sitdev->info->id << 8;
+ clkid |= (u64)sitdev->client->addr;
+
+ return clkid;
+}
+
+/*
+ * Board-config overrides for fixed efuse/blob routing the chip registers do
+ * not describe unambiguously. Absent properties leave pll_fvco[] zeroed
+ * (derive from DIVN) and out_pll_map_valid false (use the OUT_MAP registers).
+ */
+static void sit9531x_parse_board_config(struct sit9531x_dev *sitdev)
+{
+ u32 map[SIT9531X_MAX_OUTPUTS];
+ int n, i;
+
+ device_property_read_u64_array(sitdev->dev, "sitime,pll-fvco",
+ sitdev->pll_fvco, SIT9531X_NUM_PLLS);
+
+ if (!device_property_present(sitdev->dev, "sitime,output-pll-map"))
+ return;
+
+ /*
+ * Any 1..MAX_OUTPUTS length is accepted so the 8-output SiT95317 need
+ * not pad to 12; variant detection has not run yet and entries past
+ * the detected num_outputs are never indexed. Trailing entries of a
+ * short map must read as unmapped rather than 0 (== PLLA), which
+ * would mark unrouted outputs active in sit9531x_out_state_fetch().
+ */
+ memset(sitdev->out_pll_map, SIT9531X_OUT_PLL_UNMAPPED,
+ sizeof(sitdev->out_pll_map));
+
+ n = device_property_count_u32(sitdev->dev, "sitime,output-pll-map");
+ if (n <= 0 || n > SIT9531X_MAX_OUTPUTS ||
+ device_property_read_u32_array(sitdev->dev, "sitime,output-pll-map",
+ map, n))
+ return;
+
+ for (i = 0; i < n; i++)
+ sitdev->out_pll_map[i] = map[i];
+ sitdev->out_pll_map_valid = true;
+}
+
+int sit9531x_dev_probe(struct sit9531x_dev *sitdev)
+{
+ struct clk *xtal_clk;
+ u8 variant_id;
+ int rc;
+
+ /*
+ * Fvco = Fref * (DIVN + frac/2^32) with Fref = xtal_freq << doubler,
+ * so every freq_set and phase_adjust path divides by a rate derived
+ * from the XO feeding XIN/XO_CLK.
+ */
+ xtal_clk = devm_clk_get_enabled(sitdev->dev, "xtal");
+ if (IS_ERR(xtal_clk))
+ return dev_err_probe(sitdev->dev, PTR_ERR(xtal_clk),
+ "Failed to get xtal clock\n");
+ sitdev->xtal_freq = clk_get_rate(xtal_clk);
+ if (!sitdev->xtal_freq)
+ return dev_err_probe(sitdev->dev, -EINVAL,
+ "xtal clock has no rate\n");
+
+ /*
+ * Held deasserted, never pulsed: the chip configuration comes from
+ * efuse or an NVM blob applied before probe, and a reset would
+ * discard it. Must precede the first I2C access, as a board that
+ * powers up asserted keeps the chip unreachable until released.
+ */
+ sitdev->reset_gpio = devm_gpiod_get_optional(sitdev->dev, "reset",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(sitdev->reset_gpio))
+ return dev_err_probe(sitdev->dev, PTR_ERR(sitdev->reset_gpio),
+ "Failed to request reset gpio\n");
+ if (sitdev->reset_gpio)
+ fsleep(10000); /* internal boot after release */
+
+ sit9531x_parse_board_config(sitdev);
+
+ rc = sit9531x_read_variant_id(sitdev, &variant_id);
+ if (rc)
+ return rc;
+
+ sitdev->info = sit9531x_match_variant(variant_id);
+ if (!sitdev->info)
+ return dev_err_probe(sitdev->dev, -ENODEV,
+ "Unknown variant ID: 0x%02x\n", variant_id);
+
+ sitdev->clock_id = sit9531x_derive_clock_id(sitdev);
+ sitdev->intsync_src = -1;
+
+ rc = devm_mutex_init(sitdev->dev, &sitdev->multiop_lock);
+ if (rc)
+ return dev_err_probe(sitdev->dev, rc,
+ "Failed to initialize mutex\n");
+
+ /*
+ * Before the IRQ: the handler reaches sitdev->kworker through
+ * kthread_mod_delayed_work(), so the worker has to exist before an
+ * INTRB assertion can land.
+ */
+ rc = sit9531x_devm_dpll_init(sitdev);
+ if (rc)
+ return rc;
+
+ /* Absent "interrupts" leaves client->irq 0 and the poll in charge. */
+ sitdev->irq = sitdev->client ? sitdev->client->irq : 0;
+ if (sitdev->irq > 0) {
+ rc = devm_request_threaded_irq(sitdev->dev, sitdev->irq,
+ NULL, sit9531x_irq_thread_fn,
+ IRQF_ONESHOT,
+ dev_name(sitdev->dev), sitdev);
+ if (rc)
+ return dev_err_probe(sitdev->dev, rc,
+ "Failed to request IRQ %d\n",
+ sitdev->irq);
+ }
+
+ return 0;
+}
+
+static int sit9531x_i2c_probe(struct i2c_client *client)
+{
+ struct sit9531x_dev *sitdev;
+ struct regmap *regmap;
+
+ regmap = devm_regmap_init_i2c(client, &sit9531x_regmap_config);
+ if (IS_ERR(regmap))
+ return dev_err_probe(&client->dev, PTR_ERR(regmap),
+ "Failed to initialize regmap\n");
+
+ sitdev = devm_kzalloc(&client->dev, sizeof(*sitdev), GFP_KERNEL);
+ if (!sitdev)
+ return -ENOMEM;
+
+ sitdev->dev = &client->dev;
+ sitdev->client = client;
+ sitdev->regmap = regmap;
+ i2c_set_clientdata(client, sitdev);
+
+ return sit9531x_dev_probe(sitdev);
+}
+
+static const struct of_device_id sit9531x_of_match[] = {
+ { .compatible = "sitime,sit95316" },
+ { .compatible = "sitime,sit95317" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sit9531x_of_match);
+
+static struct i2c_driver sit9531x_i2c_driver = {
+ .driver = {
+ .name = "sit9531x",
+ .of_match_table = sit9531x_of_match,
+ },
+ .probe = sit9531x_i2c_probe,
+};
+module_i2c_driver(sit9531x_i2c_driver);
+
+MODULE_AUTHOR("Ali Rouhi <arouhi@sitime.com>");
+MODULE_AUTHOR("Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>");
+MODULE_DESCRIPTION("SiTime SiT9531x DPLL subsystem driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/dpll/sit9531x/core.h b/drivers/dpll/sit9531x/core.h
new file mode 100644
index 000000000000..05d4ee0c712e
--- /dev/null
+++ b/drivers/dpll/sit9531x/core.h
@@ -0,0 +1,372 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SiTime SiT9531x DPLL core driver
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ *
+ * Device structure, register access helpers, and core function
+ * declarations.
+ */
+
+#ifndef _SIT9531X_CORE_H
+#define _SIT9531X_CORE_H
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include "regs.h"
+
+#define SIT9531X_NUM_PLLS 4
+#define SIT9531X_MAX_INPUTS 8
+#define SIT9531X_NUM_INPUT_PAIRS (SIT9531X_MAX_INPUTS / 2)
+#define SIT9531X_MAX_OUTPUTS 12
+/* out_pll_map[] entry meaning "this output is not routed to any PLL" */
+#define SIT9531X_OUT_PLL_UNMAPPED 0xFF
+/*
+ * INTSYNC (the inter-PLL sync net) is modelled as two pins. The
+ * destination PLL that locks to INTSYNC sees an input pin
+ * (SIT9531X_INTSYNC_PIN_ID, in the input id namespace after the physical
+ * inputs and the xtal); the source PLL that drives INTSYNC sees an output
+ * pin (SIT9531X_INTSYNC_OUT_PIN_ID, appended after the physical outputs).
+ */
+#define SIT9531X_INTSYNC_PIN_ID (SIT9531X_MAX_INPUTS + 1)
+#define SIT9531X_INTSYNC_OUT_PIN_ID SIT9531X_MAX_OUTPUTS
+#define SIT9531X_NUM_PINS (SIT9531X_MAX_INPUTS + 2 + SIT9531X_MAX_OUTPUTS + 1)
+#define SIT9531X_STATUS_POLL_MS 500
+
+/* selected_ref value when the active source is not a registered input */
+#define SIT9531X_REF_INVALID 0xFF
+
+/* SiTime IEEE OUI for EUI-64 generation */
+#define SIT9531X_OUI 0x0090C2FFFEULL
+
+struct sit9531x_dpll;
+
+/*
+ * struct sit9531x_chip_info - chip variant identification
+ * @id: variant ID byte read from register
+ * @num_inputs: number of input clock pins
+ * @num_outputs: number of output clock pins
+ * @name: human-readable variant name
+ * @clkout_map: per-output slot mapping (output index -> physical slot)
+ */
+struct sit9531x_chip_info {
+ u8 id;
+ u8 num_inputs;
+ u8 num_outputs;
+ const char *name;
+ const u8 *clkout_map;
+};
+
+/*
+ * enum sit9531x_signal_mode - input signal electrical mode
+ * @SIT9531X_MODE_SE: single-ended
+ * @SIT9531X_MODE_DE: differential
+ */
+enum sit9531x_signal_mode {
+ SIT9531X_MODE_SE = 0,
+ SIT9531X_MODE_DE,
+};
+
+/*
+ * struct sit9531x_ref - input reference state
+ * @freq: configured frequency in Hz
+ * @enabled: reference is enabled for monitoring
+ * @los: loss-of-signal detected
+ * @oof: out-of-frequency detected
+ * @pll_mask: bitmask of PLLs this input feeds (bit 0 = PLLA)
+ * @label: board label from DT or default
+ * @sig_mode: signal mode of the pair this lane belongs to
+ * (detected from CLKINx_INPUT_MODE at probe)
+ */
+struct sit9531x_ref {
+ u32 freq;
+ bool enabled;
+ bool los;
+ bool oof;
+ u8 pll_mask;
+ const char *label;
+ enum sit9531x_signal_mode sig_mode;
+};
+
+/*
+ * struct sit9531x_out - output state
+ * @enabled: output is driving, i.e. not forced into Hi-Z
+ * @routed: output is mapped to @pll_idx by the initial
+ * configuration; an unrouted output has no DPLL pin
+ * @pll_idx: PLL driving this output (0-3)
+ * @label: board label from DT or default
+ */
+struct sit9531x_out {
+ u32 freq;
+ bool enabled;
+ bool routed;
+ u8 pll_idx;
+ const char *label;
+};
+
+/*
+ * struct sit9531x_chan - per-PLL channel state
+ * @active: PLL has reached its active state; a PLL the loaded
+ * configuration leaves unused never does, and its
+ * loss-of-lock bit stays clear because nothing drives it
+ * @locked: PLL is locked (raw status register bit)
+ * @mode: 0 = sync (outer loop enabled), 1 = free-run
+ * @selected_ref: logical input index of the currently selected
+ * reference (the INTSYNC net maps to
+ * SIT9531X_INTSYNC_PIN_ID), or SIT9531X_REF_INVALID
+ * when the hardware source encoding is reserved
+ * @inner_lol: PLL inner loop loss-of-lock detected
+ * @ho_freeze: holdover freeze active
+ */
+struct sit9531x_chan {
+ bool active;
+ bool locked;
+ u8 mode;
+ u8 selected_ref;
+ bool inner_lol;
+ bool ho_freeze;
+};
+
+/*
+ * struct sit9531x_dev - SiT9531x device instance
+ * @info: detected chip variant info
+ * @multiop_lock: mutex for multi-register atomic operations
+ * @ref: array of input reference states
+ * @out: array of output states
+ * @chan: array of per-PLL channel states
+ * @xtal_freq: crystal oscillator frequency in Hz
+ * @kworker: kthread worker for periodic polling
+ * @work: delayed work for periodic state checks
+ * @clock_id: IEEE 1588 EUI-64 clock identifier
+ * @reset_gpio: optional reset line (DT "reset-gpios"), NULL if absent
+ * @irq: optional INTRB IRQ number (from DT "interrupts" via the
+ * I2C client), 0 if no IRQ is wired
+ * @pll_fvco: optional per-PLL VCO in Hz from DT
+ * "sitime,pll-fvco"; 0 means derive from DIVN
+ * @out_pll_map: optional per-output source PLL (0-3, 0xff =
+ * unmapped) from DT "sitime,output-pll-map"
+ * @out_pll_map_valid: true when out_pll_map[] was populated from DT;
+ * false means use the chip's OUT_MAP registers
+ * @intsync_src: PLL index currently sourcing inter-PLL
+ * synchronization (INTSYNC), or -1 when disabled
+ */
+struct sit9531x_dev {
+ struct device *dev;
+ struct i2c_client *client;
+ struct regmap *regmap;
+ const struct sit9531x_chip_info *info;
+ /* Serializes multi-step register sequences */
+ struct mutex multiop_lock;
+
+ /* Hardware state */
+ struct sit9531x_ref ref[SIT9531X_MAX_INPUTS + 1]; /* +1 for xtal */
+ struct sit9531x_out out[SIT9531X_MAX_OUTPUTS];
+ struct sit9531x_chan chan[SIT9531X_NUM_PLLS];
+ u32 xtal_freq;
+
+ /* DPLL channels */
+ struct list_head dplls;
+
+ /* Monitor */
+ struct kthread_worker *kworker;
+ struct kthread_delayed_work work;
+
+ /* Device identity */
+ u64 clock_id;
+
+ /* Optional DT-described GPIO / IRQ lines */
+ struct gpio_desc *reset_gpio;
+ int irq;
+
+ /* Optional DT board-config overrides */
+ u64 pll_fvco[SIT9531X_NUM_PLLS];
+ u8 out_pll_map[SIT9531X_MAX_OUTPUTS];
+ bool out_pll_map_valid;
+
+ /* Inter-PLL synchronization state */
+ s8 intsync_src;
+
+};
+
+extern const struct regmap_config sit9531x_regmap_config;
+
+/* ---- Core lifecycle ---- */
+int sit9531x_dev_probe(struct sit9531x_dev *sitdev);
+int sit9531x_dev_start(struct sit9531x_dev *sitdev);
+void sit9531x_dev_stop(struct sit9531x_dev *sitdev);
+
+/* ---- Register access ---- */
+int sit9531x_read_u8(struct sit9531x_dev *sitdev, unsigned int reg,
+ u8 *val);
+int sit9531x_write_u8(struct sit9531x_dev *sitdev, unsigned int reg,
+ u8 val);
+int sit9531x_read_pll_u8(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 offset, u8 *val);
+int sit9531x_write_pll_u8(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 offset, u8 val);
+int sit9531x_update_pll_u8(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 offset, u8 mask, u8 val);
+
+/* ---- Input enable/disable ---- */
+int sit9531x_input_disable(struct sit9531x_dev *sitdev, u8 index);
+int sit9531x_input_enable(struct sit9531x_dev *sitdev, u8 index);
+
+/* ---- Input priority ---- */
+int sit9531x_input_prio_set(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx, u8 prio);
+int sit9531x_input_prio_get(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx, u8 *prio);
+int sit9531x_input_prio_remove(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx);
+int sit9531x_input_prio_add(struct sit9531x_dev *sitdev, u8 pll_idx,
+ u8 input_idx);
+
+/* ---- Output enable/disable (Hi-Z control) ---- */
+int sit9531x_output_disable(struct sit9531x_dev *sitdev, u8 index);
+int sit9531x_output_enable(struct sit9531x_dev *sitdev, u8 index);
+
+/* ---- Output frequency ---- */
+int sit9531x_output_freq_set(struct sit9531x_dev *sitdev, u8 out_idx,
+ u8 pll_idx, u64 frequency);
+int sit9531x_output_freq_get(struct sit9531x_dev *sitdev, u8 out_idx,
+ u64 *frequency);
+
+/* ---- Output phase adjust (PRG_RST_DELAY register-based) ---- */
+int sit9531x_output_phase_adjust_set(struct sit9531x_dev *sitdev,
+ u8 out_idx, s32 phase_ps);
+
+/* ---- Notification clear ---- */
+int sit9531x_clear_notifications(struct sit9531x_dev *sitdev);
+
+/* ---- INTSYNC (inter-PLL synchronization) ---- */
+int sit9531x_intsync_enable(struct sit9531x_dev *sitdev, u8 src_pll_idx);
+int sit9531x_intsync_disable(struct sit9531x_dev *sitdev, u8 src_pll_idx);
+
+/* ---- Output pulse control ---- */
+int sit9531x_output_pulse_ctrl_set(struct sit9531x_dev *sitdev,
+ u8 out_idx, u8 pulse_ctrl);
+
+/* ---- Phase offset (TDC readback) ---- */
+int sit9531x_pll_ffo_ppt(struct sit9531x_dev *sitdev, u8 pll_idx, s64 *ffo);
+int sit9531x_phase_offset_read(struct sit9531x_dev *sitdev, u8 pll_idx,
+ s64 *phase_ps);
+
+/* ---- State helpers ---- */
+
+/*
+ * sit9531x_pll_page - get register page for PLL index
+ * @pll_idx: PLL index (0 = PLLA, 3 = PLLD)
+ */
+static inline u8 sit9531x_pll_page(u8 pll_idx)
+{
+ return SIT9531X_PAGE_PLLA + pll_idx;
+}
+
+/*
+ * Logical input pins are interleaved: even index = P lane, odd
+ * index = N lane of pair index/2 (IN0P, IN0N, IN1P, IN1N, ...).
+ * Index SIT9531X_MAX_INPUTS is the XO input.
+ */
+
+/*
+ * sit9531x_input_pair - get input pair number for a logical input index
+ * @index: logical input pin index
+ */
+static inline u8 sit9531x_input_pair(u8 index)
+{
+ return index >> 1;
+}
+
+/*
+ * sit9531x_input_is_n - check if a logical input index is an N lane
+ * @index: logical input pin index
+ */
+static inline bool sit9531x_input_is_n(u8 index)
+{
+ return index & 1;
+}
+
+/*
+ * sit9531x_input_hw_src - translate logical input index to source encoding
+ * @index: logical input pin index
+ *
+ * The priority table and CLK_ACTIVESEL registers use a non-contiguous
+ * source encoding: 0-3 = CLK0P..CLK3P, 5 = OCXO, 6 = INTSYNC,
+ * 7-10 = CLK0N..CLK3N.
+ */
+static inline u8 sit9531x_input_hw_src(u8 index)
+{
+ if (index == SIT9531X_MAX_INPUTS)
+ return SIT9531X_PRIO_SRC_OCXO;
+ if (index == SIT9531X_INTSYNC_PIN_ID)
+ return SIT9531X_PRIO_SRC_INTSYNC;
+ if (sit9531x_input_is_n(index))
+ return SIT9531X_PRIO_SRC_N_BASE + sit9531x_input_pair(index);
+ return sit9531x_input_pair(index);
+}
+
+/*
+ * sit9531x_hw_src_input - translate source encoding to logical input index
+ * @src: 4-bit hardware source encoding
+ *
+ * Return: logical input index (INTSYNC maps to SIT9531X_INTSYNC_PIN_ID),
+ * or SIT9531X_REF_INVALID if @src is a reserved value
+ */
+static inline u8 sit9531x_hw_src_input(u8 src)
+{
+ if (src < SIT9531X_NUM_INPUT_PAIRS)
+ return src * 2;
+ if (src == SIT9531X_PRIO_SRC_OCXO)
+ return SIT9531X_MAX_INPUTS;
+ if (src == SIT9531X_PRIO_SRC_INTSYNC)
+ return SIT9531X_INTSYNC_PIN_ID;
+ if (src >= SIT9531X_PRIO_SRC_N_BASE &&
+ src < SIT9531X_PRIO_SRC_N_BASE + SIT9531X_NUM_INPUT_PAIRS)
+ return (src - SIT9531X_PRIO_SRC_N_BASE) * 2 + 1;
+ return SIT9531X_REF_INVALID;
+}
+
+/*
+ * sit9531x_ref_state_get - get reference state by index
+ * @index: logical input index
+ *
+ * Return: pointer to the cached input reference state
+ */
+static inline const struct sit9531x_ref *
+sit9531x_ref_state_get(const struct sit9531x_dev *sitdev, u8 index)
+{
+ return &sitdev->ref[index];
+}
+
+/*
+ * sit9531x_out_state_get - get output state by index
+ * @index: logical output index
+ *
+ * Return: pointer to the cached output state
+ */
+static inline const struct sit9531x_out *
+sit9531x_out_state_get(const struct sit9531x_dev *sitdev, u8 index)
+{
+ return &sitdev->out[index];
+}
+
+/*
+ * sit9531x_chan_state_get - get channel state by PLL index
+ *
+ * Return: pointer to the cached per-PLL channel state
+ */
+static inline const struct sit9531x_chan *
+sit9531x_chan_state_get(const struct sit9531x_dev *sitdev, u8 pll_idx)
+{
+ return &sitdev->chan[pll_idx];
+}
+
+#endif /* _SIT9531X_CORE_H */
diff --git a/drivers/dpll/sit9531x/dpll.c b/drivers/dpll/sit9531x/dpll.c
new file mode 100644
index 000000000000..e258beceffdd
--- /dev/null
+++ b/drivers/dpll/sit9531x/dpll.c
@@ -0,0 +1,1232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SiTime SiT9531x DPLL subsystem callbacks and registration
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ *
+ * DPLL device ops, pin ops (separate input/output), pin registration,
+ * and periodic change detection.
+ */
+
+#include <linux/dpll.h>
+#include <linux/err.h>
+#include <linux/kthread.h>
+#include <linux/list.h>
+#include <linux/netlink.h>
+#include <linux/slab.h>
+
+#include "core.h"
+#include "dpll.h"
+#include "prop.h"
+#include "regs.h"
+
+#define SIT9531X_ESYNC_FREQ_10MHZ 10000000ULL
+#define SIT9531X_ESYNC_PULSE_DEFAULT 50
+
+static const struct dpll_pin_frequency sit9531x_esync_ranges[] = {
+ DPLL_PIN_FREQUENCY(0),
+ DPLL_PIN_FREQUENCY(SIT9531X_ESYNC_FREQ_10MHZ),
+};
+
+static inline bool
+sit9531x_dpll_esync_pin_supported(const struct sit9531x_dpll_pin *dpin)
+{
+ return dpin->esync_control;
+}
+
+static inline bool sit9531x_dpll_is_input_pin(const struct sit9531x_dpll_pin *pin)
+{
+ return pin->dir == DPLL_PIN_DIRECTION_INPUT;
+}
+
+static inline bool
+sit9531x_dpll_is_intsync_pin(const struct sit9531x_dpll_pin *pin)
+{
+ return sit9531x_dpll_is_input_pin(pin) &&
+ pin->id == SIT9531X_INTSYNC_PIN_ID;
+}
+
+static inline bool
+sit9531x_dpll_is_intsync_src_pin(const struct sit9531x_dpll_pin *pin)
+{
+ return !sit9531x_dpll_is_input_pin(pin) &&
+ pin->id == SIT9531X_INTSYNC_OUT_PIN_ID;
+}
+
+static inline bool
+sit9531x_dpll_is_xo_pin(const struct sit9531x_dpll_pin *pin)
+{
+ return sit9531x_dpll_is_input_pin(pin) &&
+ pin->id == SIT9531X_MAX_INPUTS;
+}
+
+/*
+ * The cached state this reports comes from the outer loss-of-lock byte
+ * (page 0, reg 0x06), the PLL mode bit (PLL page, reg 0x31), inner LOL
+ * (reg 0x92) and the holdover freeze byte (reg 0x0A).
+ */
+static int
+sit9531x_dpll_lock_status_get(const struct dpll_device *dpll, void *dpll_priv,
+ enum dpll_lock_status *status,
+ enum dpll_lock_status_error *status_error,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ const struct sit9531x_chan *chan;
+
+ if (status_error)
+ *status_error = DPLL_LOCK_STATUS_ERROR_NONE;
+
+ chan = sit9531x_chan_state_get(sitdev, sitdpll->id);
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ if (!chan->active) {
+ /*
+ * A PLL the loaded configuration leaves unused never reaches
+ * its active state. Nothing drives its loss-of-lock bit, so
+ * without this it would report a lock it does not have.
+ */
+ *status = DPLL_LOCK_STATUS_UNLOCKED;
+ } else if (chan->locked) {
+ if (chan->mode)
+ *status = DPLL_LOCK_STATUS_LOCKED; /* free-run */
+ else
+ *status = DPLL_LOCK_STATUS_LOCKED_HO_ACQ; /* sync */
+ } else if (chan->ho_freeze) {
+ *status = DPLL_LOCK_STATUS_HOLDOVER;
+ } else {
+ *status = DPLL_LOCK_STATUS_UNLOCKED;
+ }
+
+ /* Report inner LOL as an error condition */
+ if (status_error && chan->inner_lol)
+ *status_error = DPLL_LOCK_STATUS_ERROR_UNDEFINED;
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_mode_get - report current PLL operating mode
+ *
+ * reads outer loop disable bit (PLL page reg 0x31[5]).
+ * Free-run -> MANUAL, sync -> AUTOMATIC.
+ */
+static int
+sit9531x_dpll_mode_get(const struct dpll_device *dpll, void *dpll_priv,
+ enum dpll_mode *mode, struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ const struct sit9531x_chan *chan;
+
+ chan = sit9531x_chan_state_get(sitdev, sitdpll->id);
+
+ mutex_lock(&sitdev->multiop_lock);
+ *mode = chan->mode ? DPLL_MODE_MANUAL : DPLL_MODE_AUTOMATIC;
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_mode_set - switch PLL between free-run and sync mode
+ *
+ * writes PLL page reg 0x31[5] to enable/disable the
+ * outer loop, then triggers a small update via reg 0x0F.
+ *
+ * The driver maps AUTOMATIC to sync mode (outer loop enabled; the PLL
+ * selects its reference automatically from the priority table) and
+ * MANUAL to free-run (outer loop disabled via bit 0x31[5]). The chip
+ * also has a separate manual-active-select path (MANUAL_ACTIVE_SEL_PLL
+ * plus the per-PLL man_in_sel registers) that can pin one reference
+ * while still syncing; that path is not wired to a DPLL callback here.
+ */
+static int
+sit9531x_dpll_mode_set(const struct dpll_device *dpll, void *dpll_priv,
+ enum dpll_mode mode, struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ u8 val;
+ int rc;
+
+ /*
+ * Outer loop disable bit:
+ * 0 = sync mode (outer loop enabled) -> AUTOMATIC
+ * 1 = free-run (outer loop disabled) -> MANUAL
+ */
+ val = (mode == DPLL_MODE_MANUAL) ? SIT9531X_PLL_STATUS_OUTER_DIS : 0;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ rc = sit9531x_update_pll_u8(sitdev, sitdpll->id,
+ SIT9531X_PLL_REG_STATUS,
+ SIT9531X_PLL_STATUS_OUTER_DIS, val);
+ if (rc) {
+ NL_SET_ERR_MSG(extack, "Failed to write PLL mode register");
+ goto unlock;
+ }
+
+ /* Trigger small update to apply without full NVM cycle */
+ rc = sit9531x_write_pll_u8(sitdev, sitdpll->id,
+ SIT9531X_PLL_REG_SMALL_UPDATE,
+ SIT9531X_SMALL_UPDATE_CMD);
+ if (rc) {
+ NL_SET_ERR_MSG(extack, "Failed to trigger small update");
+ goto unlock;
+ }
+
+ /*
+ * Keep the cached mode in step with the register. The periodic
+ * monitor refreshes it too, but mode_get and the reference-selection
+ * path read this cache and would otherwise report or act on the
+ * pre-switch mode until the next poll.
+ */
+ sitdev->chan[sitdpll->id].mode = !!val;
+
+unlock:
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return rc;
+}
+
+static int
+sit9531x_dpll_supported_modes_get(const struct dpll_device *dpll,
+ void *dpll_priv, unsigned long *modes,
+ struct netlink_ext_ack *extack)
+{
+ __set_bit(DPLL_MODE_AUTOMATIC, modes);
+ __set_bit(DPLL_MODE_MANUAL, modes);
+
+ return 0;
+}
+
+const struct dpll_device_ops sit9531x_dpll_device_ops = {
+ .lock_status_get = sit9531x_dpll_lock_status_get,
+ .mode_get = sit9531x_dpll_mode_get,
+ .mode_set = sit9531x_dpll_mode_set,
+ .supported_modes_get = sit9531x_dpll_supported_modes_get,
+ /* temp_get not available -- SiT9531x has no on-die temp sensor */
+};
+
+static int
+sit9531x_dpll_input_pin_direction_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_direction *direction,
+ struct netlink_ext_ack *extack)
+{
+ *direction = DPLL_PIN_DIRECTION_INPUT;
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_input_pin_frequency_get - read input pin frequency
+ *
+ * returns cached frequency from DT or last set.
+ */
+static int
+sit9531x_dpll_input_pin_frequency_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, u64 *frequency,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ const struct sit9531x_ref *ref;
+
+ ref = sit9531x_ref_state_get(sitdpll->dev, dpin->id);
+ *frequency = ref->freq;
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_input_pin_state_on_dpll_get - get input pin DPLL state
+ *
+ * determines pin state from channel state: connected
+ * if this input is the selected reference on a locked PLL, selectable
+ * if enabled in automatic mode, disconnected otherwise.
+ */
+static int
+sit9531x_dpll_input_pin_state_on_dpll_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state *state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ const struct sit9531x_chan *chan;
+ const struct sit9531x_ref *ref;
+
+ chan = sit9531x_chan_state_get(sitdev, sitdpll->id);
+ ref = sit9531x_ref_state_get(sitdev, dpin->id);
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ /*
+ * Report CONNECTED only when the PLL is genuinely locked to this
+ * input. chan->locked already excludes a PLL the configuration
+ * leaves unused, which would otherwise claim its default source as
+ * connected right after probe; the inner loop has to be locked as
+ * well before the reference can be called connected.
+ */
+ if (chan->locked && !chan->inner_lol &&
+ chan->selected_ref == dpin->id)
+ *state = DPLL_PIN_STATE_CONNECTED;
+ /*
+ * Selectable means this DPLL may choose the input, so it has to be
+ * in this DPLL's priority table -- ref->enabled only says the
+ * receiver is powered, which is shared by every DPLL fed from the
+ * same lane. Signal quality is reported through the pin's own
+ * attributes rather than by demoting the state, so a lane that is
+ * routed here but momentarily in LOS stays selectable.
+ */
+ else if (!chan->mode && (ref->pll_mask & BIT(sitdpll->id)))
+ *state = DPLL_PIN_STATE_SELECTABLE;
+ else
+ *state = DPLL_PIN_STATE_DISCONNECTED;
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_input_pin_state_on_dpll_set - set input pin DPLL state
+ *
+ * Enables or disables the physical input receiver via Page 0x02
+ * force/state registers (sit9531x_input_disable/enable()) and updates
+ * this DPLL's Page 1 priority table so the state is honoured by the
+ * PLL's automatic reference selection, not just at the input buffer.
+ * DISCONNECTED -> drop the input from this DPLL's priority table and
+ * release this DPLL's claim on the input
+ * SELECTABLE -> claim the input for this DPLL and make it eligible
+ * again in the priority table
+ * CONNECTED -> same as SELECTABLE (the PLL auto-switch logic does
+ * the actual selection)
+ *
+ * The priority table is per PLL, so it is always updated for this DPLL.
+ * A single physical input feeds every DPLL, so the hardware receiver is
+ * only cut off once the last DPLL has released it: ref->pll_mask tracks
+ * which DPLLs currently claim the input, and the physical disable
+ * happens on the transition to an empty mask.
+ */
+static int
+sit9531x_dpll_input_pin_state_on_dpll_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ struct sit9531x_ref *ref = &sitdev->ref[dpin->id];
+ u8 hw_src = sit9531x_input_hw_src(dpin->id);
+ u8 pll_bit = BIT(sitdpll->id);
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ switch (state) {
+ case DPLL_PIN_STATE_DISCONNECTED:
+ rc = sit9531x_input_prio_remove(sitdev, sitdpll->id, hw_src);
+ if (rc)
+ break;
+ ref->pll_mask &= ~pll_bit;
+ if (ref->pll_mask)
+ rc = 0; /* another DPLL still uses this input */
+ else
+ rc = sit9531x_input_disable(sitdev, dpin->id);
+ break;
+ case DPLL_PIN_STATE_CONNECTED:
+ /*
+ * CONNECTED asks for this input and no other. The chip has
+ * no such mode: MANUAL disables the outer loop rather than
+ * pinning a reference, so honouring the request would mean
+ * emptying the priority table of every other source, which
+ * is not what the caller asked for. Refuse instead of
+ * quietly behaving like SELECTABLE.
+ */
+ NL_SET_ERR_MSG(extack,
+ "Device selects its reference by priority; use selectable");
+ rc = -EOPNOTSUPP;
+ break;
+ case DPLL_PIN_STATE_SELECTABLE:
+ rc = sit9531x_input_enable(sitdev, dpin->id);
+ if (rc)
+ break;
+ rc = sit9531x_input_prio_add(sitdev, sitdpll->id, hw_src);
+ if (rc)
+ break;
+ /*
+ * Claim the input for this DPLL only once it is both enabled
+ * and present in the priority table. Setting the mask before
+ * prio_add would leak the claim if prio_add failed, keeping the
+ * shared input receiver powered even after every DPLL released
+ * it.
+ */
+ ref->pll_mask |= pll_bit;
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc)
+ NL_SET_ERR_MSG(extack, "Failed to set input pin state");
+
+ return rc;
+}
+
+/*
+ * sit9531x_dpll_input_pin_prio_get - read input pin priority
+ *
+ * reads the PLL's priority table on Page 1 (via
+ * sit9531x_input_prio_get()) and returns the slot the input
+ * occupies, so pin-get reports the real hardware priority rather
+ * than a software default.
+ */
+static int
+sit9531x_dpll_input_pin_prio_get(const struct dpll_pin *pin, void *pin_priv,
+ const struct dpll_device *dpll, void *dpll_priv,
+ u32 *prio, struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ u8 slot;
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_input_prio_get(sitdev, sitdpll->id,
+ sit9531x_input_hw_src(dpin->id), &slot);
+ mutex_unlock(&sitdev->multiop_lock);
+ if (rc)
+ return rc;
+
+ dpin->prio = slot;
+ *prio = slot;
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_input_pin_prio_set - set input pin priority
+ *
+ * writes input priority table on Page 1 via
+ * core.c sit9531x_input_prio_set(). Forces holdover during update.
+ */
+static int
+sit9531x_dpll_input_pin_prio_set(const struct dpll_pin *pin, void *pin_priv,
+ const struct dpll_device *dpll, void *dpll_priv,
+ u32 prio, struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc;
+
+ if (dpin->dir != DPLL_PIN_DIRECTION_INPUT) {
+ NL_SET_ERR_MSG(extack, "Priority applies only to input pins");
+ return -EINVAL;
+ }
+
+ if (prio >= SIT9531X_PRIO_MAX_SLOTS) {
+ NL_SET_ERR_MSG(extack, "Priority out of range (0-10)");
+ return -EINVAL;
+ }
+
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_input_prio_set(sitdev, sitdpll->id,
+ sit9531x_input_hw_src(dpin->id),
+ (u8)prio);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc) {
+ NL_SET_ERR_MSG(extack, "Failed to set input priority");
+ return rc;
+ }
+
+ dpin->prio = (u8)prio;
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_input_pin_phase_adjust_get - read phase adjustment
+ *
+ * returns cached phase adjustment value (in ps).
+ */
+static int
+sit9531x_dpll_input_pin_phase_adjust_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, s32 *phase_adjust,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+
+ *phase_adjust = dpin->phase_adjust;
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_input_pin_phase_offset_get - read phase offset
+ *
+ * reads the TDC (Time-to-Digital Converter) hardware
+ * to measure the phase difference in picoseconds via
+ * sit9531x_phase_offset_read().
+ */
+/*
+ * sit9531x_dpll_input_pin_ffo_get - read the input's frequency offset
+ *
+ * The offset is derived from how far the PLL's running DIVN sits from
+ * its configured one, which only says something about the reference the
+ * PLL is actually tracking. For every other input there is no
+ * measurement, and -ENODATA leaves the attribute out rather than
+ * reporting the active reference's figure against the wrong pin.
+ */
+static int
+sit9531x_dpll_input_pin_ffo_get(const struct dpll_pin *pin, void *pin_priv,
+ const struct dpll_device *dpll, void *dpll_priv,
+ struct dpll_ffo_param *ffo,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc;
+
+ if (sitdev->chan[sitdpll->id].selected_ref != dpin->id)
+ return -ENODATA;
+
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_pll_ffo_ppt(sitdev, sitdpll->id, &ffo->ffo);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return rc;
+}
+
+static int
+sit9531x_dpll_input_pin_phase_offset_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, s64 *phase_offset,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ s64 offset;
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ /*
+ * The on-chip TDC is a per-PLL resource that always measures the
+ * phase difference between the VCO and the PLL's currently
+ * selected reference; it cannot be pointed at an arbitrary input.
+ * For any input that is not the active reference there is no
+ * meaningful per-pin phase offset, so report 0 instead of the
+ * active reference's value.
+ */
+ if (sitdev->chan[sitdpll->id].selected_ref != dpin->id) {
+ mutex_unlock(&sitdev->multiop_lock);
+ dpin->phase_offset = 0;
+ *phase_offset = 0;
+ return 0;
+ }
+
+ rc = sit9531x_phase_offset_read(sitdev, sitdpll->id, &offset);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ /*
+ * -ENODEV means the PLL has no programmed DIVN (unused on this
+ * board); report phase_offset = 0 so a full pin-get dump does not
+ * fail just because one DPLL is dormant.
+ */
+ if (rc == -ENODEV) {
+ dpin->phase_offset = 0;
+ *phase_offset = 0;
+ return 0;
+ }
+ if (rc) {
+ NL_SET_ERR_MSG(extack, "TDC phase readback failed");
+ return rc;
+ }
+
+ /*
+ * The ABI reports phase offset in units of 1/DPLL_PHASE_OFFSET_DIVIDER
+ * picoseconds: the integer part of the attribute is the value divided
+ * by the divider, the remainder is the fraction. The TDC resolves one
+ * VCO period (hundreds of picoseconds), so the fractional digits are
+ * always zero here, but the magnitude still has to be scaled or every
+ * reading would be reported a thousand times too small.
+ */
+ offset *= DPLL_PHASE_OFFSET_DIVIDER;
+
+ dpin->phase_offset = offset;
+ *phase_offset = offset;
+ return 0;
+}
+
+static const struct dpll_pin_ops sit9531x_dpll_input_pin_ops = {
+ .direction_get = sit9531x_dpll_input_pin_direction_get,
+ .frequency_get = sit9531x_dpll_input_pin_frequency_get,
+ .state_on_dpll_get = sit9531x_dpll_input_pin_state_on_dpll_get,
+ .state_on_dpll_set = sit9531x_dpll_input_pin_state_on_dpll_set,
+ .prio_get = sit9531x_dpll_input_pin_prio_get,
+ .prio_set = sit9531x_dpll_input_pin_prio_set,
+ .phase_adjust_get = sit9531x_dpll_input_pin_phase_adjust_get,
+ .phase_offset_get = sit9531x_dpll_input_pin_phase_offset_get,
+ /*
+ * The measurement compares the PLL's running feedback divider with
+ * its configured one, so it describes the device's own reference
+ * rather than a port rate.
+ */
+ .supported_ffo = BIT(DPLL_FFO_PIN_DEVICE),
+ .ffo_get = sit9531x_dpll_input_pin_ffo_get,
+};
+
+/*
+ * INTSYNC pin ops
+ *
+ * INTSYNC is the chip's inter-PLL sync net: one PLL drives it and other
+ * PLLs may lock to it instead of to an external reference. The two
+ * roles are exposed as two separate pins so neither overloads the other:
+ *
+ * - a source (output) pin registered on every DPLL. Connecting it on a
+ * DPLL makes that DPLL drive INTSYNC; only one DPLL may drive it at a
+ * time. It has no priority ops -- driving the net is not a reference
+ * selection.
+ * - a destination (input) pin registered on every DPLL. Connecting it
+ * on a DPLL makes that DPLL eligible to lock to INTSYNC as a
+ * reference, so it carries the priority ops.
+ */
+
+/* ---- INTSYNC source (output) pin ---- */
+
+/* The INTSYNC source pin is an output; its direction_get is defined below. */
+static int
+sit9531x_dpll_output_pin_direction_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_direction *direction,
+ struct netlink_ext_ack *extack);
+
+static int
+sit9531x_dpll_intsync_src_state_on_dpll_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state *state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+
+ mutex_lock(&sitdev->multiop_lock);
+ if (sitdev->intsync_src == sitdpll->id)
+ *state = DPLL_PIN_STATE_CONNECTED;
+ else
+ *state = DPLL_PIN_STATE_DISCONNECTED;
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_intsync_src_state_on_dpll_set - drive INTSYNC from a PLL
+ *
+ * CONNECTED -> this PLL drives the INTSYNC net
+ * DISCONNECTED -> stop driving INTSYNC if this PLL drives it
+ *
+ * SELECTABLE is rejected: driving the net is an explicit output routing,
+ * not an automatic-selection candidate, matching the regular output pin.
+ */
+static int
+sit9531x_dpll_intsync_src_state_on_dpll_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc = 0;
+ u8 prio;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ switch (state) {
+ case DPLL_PIN_STATE_CONNECTED:
+ if (sitdev->intsync_src == sitdpll->id)
+ break;
+ if (sitdev->intsync_src >= 0) {
+ NL_SET_ERR_MSG(extack,
+ "INTSYNC is already sourced by another PLL");
+ rc = -EBUSY;
+ break;
+ }
+ /*
+ * A PLL that already lists INTSYNC among its references must
+ * not also drive it: the destination side refuses the mirror
+ * of this, and without the check here the net could be routed
+ * back into the PLL feeding it.
+ */
+ rc = sit9531x_input_prio_get(sitdev, sitdpll->id,
+ sit9531x_input_hw_src(SIT9531X_INTSYNC_PIN_ID),
+ &prio);
+ if (rc)
+ break;
+ if (prio < SIT9531X_PRIO_MAX_SLOTS) {
+ NL_SET_ERR_MSG(extack,
+ "PLL selects INTSYNC as a reference; it cannot drive it");
+ rc = -EBUSY;
+ break;
+ }
+ rc = sit9531x_intsync_enable(sitdev, sitdpll->id);
+ if (!rc)
+ sitdev->intsync_src = sitdpll->id;
+ break;
+ case DPLL_PIN_STATE_DISCONNECTED:
+ if (sitdev->intsync_src != sitdpll->id)
+ break;
+ rc = sit9531x_intsync_disable(sitdev, sitdpll->id);
+ if (!rc)
+ sitdev->intsync_src = -1;
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc && rc != -EBUSY)
+ NL_SET_ERR_MSG(extack, "Failed to set INTSYNC source state");
+
+ return rc;
+}
+
+static const struct dpll_pin_ops sit9531x_dpll_intsync_src_pin_ops = {
+ .direction_get = sit9531x_dpll_output_pin_direction_get,
+ .state_on_dpll_get = sit9531x_dpll_intsync_src_state_on_dpll_get,
+ .state_on_dpll_set = sit9531x_dpll_intsync_src_state_on_dpll_set,
+};
+
+/* ---- INTSYNC destination (input) pin ---- */
+
+/*
+ * sit9531x_dpll_intsync_dst_state_on_dpll_get - INTSYNC reference state
+ *
+ * CONNECTED when this PLL is locked to INTSYNC as its reference,
+ * SELECTABLE when it runs in automatic mode and a source PLL is driving
+ * INTSYNC, DISCONNECTED otherwise. The PLL that drives INTSYNC can never
+ * be its own destination.
+ */
+static int
+sit9531x_dpll_intsync_dst_state_on_dpll_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state *state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ const struct sit9531x_chan *chan;
+
+ chan = sit9531x_chan_state_get(sitdev, sitdpll->id);
+
+ mutex_lock(&sitdev->multiop_lock);
+ if (sitdev->intsync_src == sitdpll->id)
+ *state = DPLL_PIN_STATE_DISCONNECTED;
+ else if (chan->locked && !chan->inner_lol &&
+ chan->selected_ref == SIT9531X_INTSYNC_PIN_ID)
+ *state = DPLL_PIN_STATE_CONNECTED;
+ else if (!chan->mode && sitdev->intsync_src >= 0)
+ *state = DPLL_PIN_STATE_SELECTABLE;
+ else
+ *state = DPLL_PIN_STATE_DISCONNECTED;
+ mutex_unlock(&sitdev->multiop_lock);
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_intsync_dst_state_on_dpll_set - lock a PLL to INTSYNC
+ *
+ * CONNECTED/SELECTABLE -> add INTSYNC to this PLL's priority table
+ * DISCONNECTED -> drop INTSYNC from this PLL's priority table
+ *
+ * INTSYNC is an internal net with no physical receiver, so only the
+ * per-PLL priority table is touched; the source pin controls generation.
+ */
+static int
+sit9531x_dpll_intsync_dst_state_on_dpll_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ u8 hw_src = sit9531x_input_hw_src(SIT9531X_INTSYNC_PIN_ID);
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ switch (state) {
+ case DPLL_PIN_STATE_DISCONNECTED:
+ rc = sit9531x_input_prio_remove(sitdev, sitdpll->id, hw_src);
+ break;
+ case DPLL_PIN_STATE_SELECTABLE:
+ case DPLL_PIN_STATE_CONNECTED:
+ if (sitdev->intsync_src == sitdpll->id) {
+ NL_SET_ERR_MSG(extack,
+ "PLL cannot lock to the INTSYNC it drives");
+ rc = -EINVAL;
+ break;
+ }
+ rc = sit9531x_input_prio_add(sitdev, sitdpll->id, hw_src);
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc && rc != -EINVAL)
+ NL_SET_ERR_MSG(extack, "Failed to set INTSYNC input state");
+
+ return rc;
+}
+
+/*
+ * Do not add .frequency_get / the generic input state getter here: the
+ * destination pin id is SIT9531X_INTSYNC_PIN_ID, one past the end of the
+ * ref[] array (INTSYNC is an internal net with no ref[] entry). The ops
+ * below only ever key on chan[] and the priority table, never ref[id].
+ */
+static const struct dpll_pin_ops sit9531x_dpll_intsync_dst_pin_ops = {
+ .direction_get = sit9531x_dpll_input_pin_direction_get,
+ .state_on_dpll_get = sit9531x_dpll_intsync_dst_state_on_dpll_get,
+ .state_on_dpll_set = sit9531x_dpll_intsync_dst_state_on_dpll_set,
+ .prio_get = sit9531x_dpll_input_pin_prio_get,
+ .prio_set = sit9531x_dpll_input_pin_prio_set,
+};
+
+/*
+ * XO (crystal oscillator) pin ops
+ *
+ * The XO is the chip's internal reference oscillator that feeds every
+ * PLL. It is exposed so userspace can see the on-chip reference, but it
+ * cannot be routed or disconnected, so it is reported permanently
+ * connected and offers no state_on_dpll_set / prio ops.
+ */
+
+static int
+sit9531x_dpll_xo_pin_state_on_dpll_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state *state,
+ struct netlink_ext_ack *extack)
+{
+ *state = DPLL_PIN_STATE_CONNECTED;
+ return 0;
+}
+
+static const struct dpll_pin_ops sit9531x_dpll_xo_pin_ops = {
+ .direction_get = sit9531x_dpll_input_pin_direction_get,
+ .frequency_get = sit9531x_dpll_input_pin_frequency_get,
+ .state_on_dpll_get = sit9531x_dpll_xo_pin_state_on_dpll_get,
+};
+
+static int
+sit9531x_dpll_output_pin_direction_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_direction *direction,
+ struct netlink_ext_ack *extack)
+{
+ *direction = DPLL_PIN_DIRECTION_OUTPUT;
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_output_pin_frequency_get - read output pin frequency
+ *
+ * Reads the DIVO divider back from the chip and computes the live
+ * frequency as Fvco / DIVO. Falls back to the cached value when the
+ * output is not resolvable through the divider chain (e.g. not mapped
+ * to a PLL), so a netlink dump never fails on such pins.
+ */
+static int
+sit9531x_dpll_output_pin_frequency_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, u64 *frequency,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_output_freq_get(sitdev, dpin->id, frequency);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc)
+ *frequency = sit9531x_out_state_get(sitdev, dpin->id)->freq;
+
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_output_pin_frequency_set - set output pin frequency
+ *
+ * computes DIVO = Fvco / frequency and writes the
+ * 34-bit output divider to the output system registers via
+ * sit9531x_output_freq_set().
+ */
+static int
+sit9531x_dpll_output_pin_frequency_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, u64 frequency,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ u8 actual_pll;
+ int rc;
+
+ /*
+ * Read the PLL that drives this output from its OUT_MAP state
+ * (populated by out_state_fetch from the chip's OUT_MAP registers).
+ * That is the index the output register programming below is keyed
+ * by; the output is registered under the DPLL matching this PLL.
+ */
+ actual_pll = sitdev->out[dpin->id].pll_idx;
+
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_output_freq_set(sitdev, dpin->id, actual_pll,
+ frequency);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc)
+ NL_SET_ERR_MSG(extack, "Output frequency set failed");
+
+ return rc;
+}
+
+/*
+ * sit9531x_dpll_output_pin_state_on_dpll_get - get output pin state
+ *
+ * reports CONNECTED when the output is driven and
+ * DISCONNECTED when it has been muted via sit9531x_output_disable().
+ */
+static int
+sit9531x_dpll_output_pin_state_on_dpll_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state *state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ const struct sit9531x_out *out;
+
+ out = sit9531x_out_state_get(sitdpll->dev, dpin->id);
+ *state = out->enabled ? DPLL_PIN_STATE_CONNECTED
+ : DPLL_PIN_STATE_DISCONNECTED;
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_output_pin_state_on_dpll_set - mute/un-mute an output
+ *
+ * forces Hi-Z on the output pin via the Page 0x03
+ * force/state register pair.
+ * CONNECTED -> enable (release force, back to factory default)
+ * DISCONNECTED -> disable (force Hi-Z)
+ */
+static int
+sit9531x_dpll_output_pin_state_on_dpll_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ enum dpll_pin_state state,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ switch (state) {
+ case DPLL_PIN_STATE_CONNECTED:
+ rc = sit9531x_output_enable(sitdev, dpin->id);
+ break;
+ case DPLL_PIN_STATE_DISCONNECTED:
+ rc = sit9531x_output_disable(sitdev, dpin->id);
+ break;
+ default:
+ rc = -EINVAL;
+ break;
+ }
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc)
+ NL_SET_ERR_MSG(extack, "Failed to set output pin state");
+
+ return rc;
+}
+
+/*
+ * sit9531x_dpll_output_pin_phase_adjust_get - read output phase adjustment
+ *
+ * returns cached value.
+ */
+static int
+sit9531x_dpll_output_pin_phase_adjust_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, s32 *phase_adjust,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+
+ *phase_adjust = dpin->phase_adjust;
+ return 0;
+}
+
+/*
+ * sit9531x_dpll_output_pin_phase_adjust_set - set output phase adjustment
+ *
+ * Programs the per-output PRG_RST_DELAY registers for deterministic
+ * phase offset; see sit9531x_output_phase_adjust_set() in core.c.
+ */
+static int
+sit9531x_dpll_output_pin_phase_adjust_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv, s32 phase_adjust,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ int rc;
+
+ mutex_lock(&sitdev->multiop_lock);
+ rc = sit9531x_output_phase_adjust_set(sitdev, dpin->id, phase_adjust);
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (rc) {
+ NL_SET_ERR_MSG(extack, "Phase adjust failed");
+ return rc;
+ }
+
+ dpin->phase_adjust = phase_adjust;
+ return 0;
+}
+
+static int
+sit9531x_dpll_output_pin_esync_get(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ struct dpll_pin_esync *esync,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+
+ if (!sit9531x_dpll_esync_pin_supported(dpin))
+ return -EOPNOTSUPP;
+
+ esync->range = sit9531x_esync_ranges;
+ esync->range_num = ARRAY_SIZE(sit9531x_esync_ranges);
+ esync->pulse = SIT9531X_ESYNC_PULSE_DEFAULT;
+ esync->freq = dpin->esync_freq;
+
+ return 0;
+}
+
+static int
+sit9531x_dpll_output_pin_esync_set(const struct dpll_pin *pin,
+ void *pin_priv,
+ const struct dpll_device *dpll,
+ void *dpll_priv,
+ u64 freq,
+ struct netlink_ext_ack *extack)
+{
+ struct sit9531x_dpll_pin *dpin = pin_priv;
+ struct sit9531x_dpll *sitdpll = dpll_priv;
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ u8 actual_pll;
+ int rc;
+
+ if (!sit9531x_dpll_esync_pin_supported(dpin)) {
+ NL_SET_ERR_MSG(extack,
+ "Embedded sync not enabled for this pin");
+ return -EOPNOTSUPP;
+ }
+
+ actual_pll = sitdev->out[dpin->id].pll_idx;
+
+ mutex_lock(&sitdev->multiop_lock);
+
+ /*
+ * This output is a dedicated embedded-sync pin.
+ * Treat freq=0 as a request to disable the entire output.
+ */
+ if (!freq) {
+ rc = sit9531x_output_disable(sitdev, dpin->id);
+ if (!rc)
+ dpin->esync_freq = 0;
+ mutex_unlock(&sitdev->multiop_lock);
+ return rc;
+ }
+
+ if (freq != SIT9531X_ESYNC_FREQ_10MHZ) {
+ mutex_unlock(&sitdev->multiop_lock);
+ NL_SET_ERR_MSG(extack,
+ "Only 10 MHz esync frequency is supported");
+ return -EINVAL;
+ }
+
+ rc = sit9531x_output_freq_set(sitdev, dpin->id, actual_pll,
+ SIT9531X_ESYNC_FREQ_10MHZ);
+ /*
+ * Program the pulse generator (PROG0 PULSE_CTRL) so the embedded-sync
+ * pulse is actually emitted; without it the output carries the clock
+ * but no esync marker. SIT9531X_ESYNC_PULSE_DEFAULT is the same duty
+ * the esync_get callback advertises.
+ */
+ if (!rc)
+ rc = sit9531x_output_pulse_ctrl_set(sitdev, dpin->id,
+ SIT9531X_ESYNC_PULSE_DEFAULT);
+ if (!rc)
+ rc = sit9531x_output_enable(sitdev, dpin->id);
+
+ mutex_unlock(&sitdev->multiop_lock);
+
+ if (!rc)
+ dpin->esync_freq = SIT9531X_ESYNC_FREQ_10MHZ;
+
+ return rc;
+}
+
+static const struct dpll_pin_ops sit9531x_dpll_output_pin_ops = {
+ .direction_get = sit9531x_dpll_output_pin_direction_get,
+ .frequency_get = sit9531x_dpll_output_pin_frequency_get,
+ .frequency_set = sit9531x_dpll_output_pin_frequency_set,
+ .state_on_dpll_get = sit9531x_dpll_output_pin_state_on_dpll_get,
+ .state_on_dpll_set = sit9531x_dpll_output_pin_state_on_dpll_set,
+ .phase_adjust_get = sit9531x_dpll_output_pin_phase_adjust_get,
+ .phase_adjust_set = sit9531x_dpll_output_pin_phase_adjust_set,
+ .esync_get = sit9531x_dpll_output_pin_esync_get,
+ .esync_set = sit9531x_dpll_output_pin_esync_set,
+};
+
+const struct dpll_pin_ops *
+sit9531x_dpll_pin_ops_get(const struct sit9531x_dpll_pin *pin)
+{
+ if (!sit9531x_dpll_is_input_pin(pin)) {
+ if (sit9531x_dpll_is_intsync_src_pin(pin))
+ return &sit9531x_dpll_intsync_src_pin_ops;
+ return &sit9531x_dpll_output_pin_ops;
+ }
+ if (sit9531x_dpll_is_intsync_pin(pin))
+ return &sit9531x_dpll_intsync_dst_pin_ops;
+ if (sit9531x_dpll_is_xo_pin(pin))
+ return &sit9531x_dpll_xo_pin_ops;
+ return &sit9531x_dpll_input_pin_ops;
+}
+
+/*
+ * sit9531x_dpll_changes_check - check for state changes and notify
+ *
+ * Called from sit9531x_dev_periodic_work(). Compares current hardware
+ * state against cached values and sends netlink notifications on changes.
+ */
+void sit9531x_dpll_changes_check(struct sit9531x_dpll *sitdpll)
+{
+ struct sit9531x_dev *sitdev = sitdpll->dev;
+ enum dpll_lock_status lock_status;
+ struct sit9531x_dpll_pin *pin;
+ int rc;
+
+ rc = sit9531x_dpll_lock_status_get(sitdpll->dpll_dev, sitdpll,
+ &lock_status, NULL, NULL);
+ if (rc) {
+ dev_err(sitdev->dev, "Failed to get DPLL%u lock status: %d\n",
+ sitdpll->id, rc);
+ return;
+ }
+
+ /* If lock status changed, notify DPLL core */
+ if (sitdpll->lock_status != lock_status) {
+ sitdpll->lock_status = lock_status;
+ dpll_device_change_ntf(sitdpll->dpll_dev);
+ }
+
+ list_for_each_entry(pin, &sitdpll->pins, list) {
+ const struct dpll_pin_ops *ops;
+ enum dpll_pin_state state;
+
+ /*
+ * Poll input pins whose state can change autonomously: regular
+ * references and the INTSYNC destination pin. Outputs (incl.
+ * the INTSYNC source) change only through their own set
+ * callback and the XO is permanently connected, so skip those.
+ * Each pin's own state_on_dpll_get resolves to the right getter.
+ */
+ if (!sit9531x_dpll_is_input_pin(pin) ||
+ sit9531x_dpll_is_xo_pin(pin))
+ continue;
+
+ ops = sit9531x_dpll_pin_ops_get(pin);
+ rc = ops->state_on_dpll_get(pin->dpll_pin, pin,
+ sitdpll->dpll_dev, sitdpll,
+ &state, NULL);
+ if (rc)
+ continue;
+
+ if (state != pin->pin_state) {
+ dev_dbg(sitdev->dev, "%s state changed: %u->%u\n",
+ pin->label, pin->pin_state, state);
+ pin->pin_state = state;
+ dpll_pin_change_ntf(pin->dpll_pin);
+ }
+ }
+}
diff --git a/drivers/dpll/sit9531x/dpll.h b/drivers/dpll/sit9531x/dpll.h
new file mode 100644
index 000000000000..e5eef4514bcd
--- /dev/null
+++ b/drivers/dpll/sit9531x/dpll.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SiTime SiT9531x DPLL subsystem interface
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ *
+ * DPLL device and pin structures, and function declarations for
+ * the DPLL registration and callback layer.
+ */
+
+#ifndef _SIT9531X_DPLL_H
+#define _SIT9531X_DPLL_H
+
+#include <linux/dpll.h>
+#include <linux/list.h>
+#include <linux/types.h>
+
+struct sit9531x_dev;
+
+/* Per-pin DPLL state. */
+struct sit9531x_dpll_pin {
+ struct list_head list;
+ struct sit9531x_dpll *dpll;
+ struct dpll_pin *dpll_pin;
+ dpll_tracker tracker;
+ struct fwnode_handle *fwnode;
+ char label[8]; /* "IN0", "OUT3" */
+ enum dpll_pin_direction dir;
+ u8 id; /* hardware index */
+ u8 prio;
+ enum dpll_pin_state pin_state;
+ s32 phase_adjust; /* picoseconds */
+ s64 phase_offset; /* picoseconds */
+ bool esync_control;
+ u64 esync_freq; /* 0 == disabled */
+};
+
+/* Per-PLL DPLL device state. */
+struct sit9531x_dpll {
+ struct list_head list;
+ struct sit9531x_dev *dev;
+ struct dpll_device *dpll_dev;
+ dpll_tracker tracker;
+ struct dpll_device_ops ops; /* per-instance copy */
+ struct list_head pins;
+ u8 id; /* 0 = PLLA .. 3 = PLLD */
+ enum dpll_lock_status lock_status;
+};
+
+/* ---- DPLL allocation and registration ---- */
+/*
+ * The callback tables stay with the callbacks; the registration code that
+ * hands them to the subsystem lives next to probe() in core.c.
+ */
+extern const struct dpll_device_ops sit9531x_dpll_device_ops;
+const struct dpll_pin_ops *
+sit9531x_dpll_pin_ops_get(const struct sit9531x_dpll_pin *pin);
+
+struct sit9531x_dpll *sit9531x_dpll_alloc(struct sit9531x_dev *sitdev, u8 ch);
+void sit9531x_dpll_free(struct sit9531x_dpll *sitdpll);
+int sit9531x_dpll_register(struct sit9531x_dpll *sitdpll);
+void sit9531x_dpll_unregister(struct sit9531x_dpll *sitdpll);
+
+/* ---- Periodic change detection ---- */
+void sit9531x_dpll_changes_check(struct sit9531x_dpll *sitdpll);
+
+#endif /* _SIT9531X_DPLL_H */
diff --git a/drivers/dpll/sit9531x/prop.c b/drivers/dpll/sit9531x/prop.c
new file mode 100644
index 000000000000..8a0105c8c647
--- /dev/null
+++ b/drivers/dpll/sit9531x/prop.c
@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SiTime SiT9531x firmware node property parsing
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ *
+ * Retrieves pin properties from Device Tree firmware nodes (or
+ * applies defaults when no firmware node exists).
+ */
+
+#include <linux/dev_printk.h>
+#include <linux/dpll.h>
+#include <linux/err.h>
+#include <linux/fwnode.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "core.h"
+#include "prop.h"
+
+/*
+ * sit9531x_input_pin_label - fill the package label for an input pin
+ *
+ * Split out so input-naming changes stay local to this helper.
+ */
+static void sit9531x_input_pin_label(struct sit9531x_dev *sitdev,
+ struct sit9531x_pin_props *props, u8 id)
+{
+ u8 pair = sit9531x_input_pair(id);
+
+ if (sitdev->ref[id].sig_mode == SIT9531X_MODE_DE)
+ snprintf(props->package_label,
+ sizeof(props->package_label), "IN%u", pair);
+ else
+ snprintf(props->package_label,
+ sizeof(props->package_label), "IN%u%c", pair,
+ sit9531x_input_is_n(id) ? 'N' : 'P');
+}
+
+/*
+ * sit9531x_prop_pin_package_label_set - generate package label
+ * @dir: pin direction
+ * @id: pin index
+ *
+ * Generates a package label string. Output pins are named "OUT0",
+ * "OUT1", ... Input pins are named after the physical pair and lane:
+ * "IN0P", "IN0N", "IN1P", ... for single-ended lanes, or "IN0",
+ * "IN1", ... when the pair is configured differential (the N lane is
+ * not registered in that case).
+ */
+static void
+sit9531x_prop_pin_package_label_set(struct sit9531x_dev *sitdev,
+ struct sit9531x_pin_props *props,
+ enum dpll_pin_direction dir, u8 id)
+{
+ /* The internal INTSYNC pin has a fixed label */
+ if (dir == DPLL_PIN_DIRECTION_INPUT &&
+ id == SIT9531X_INTSYNC_PIN_ID) {
+ strscpy(props->package_label, "INTSYNC",
+ sizeof(props->package_label));
+ props->dpll_props.package_label = props->package_label;
+ return;
+ }
+
+ /* The internal XO reference has a fixed label */
+ if (dir == DPLL_PIN_DIRECTION_INPUT && id == SIT9531X_MAX_INPUTS) {
+ strscpy(props->package_label, "XO",
+ sizeof(props->package_label));
+ props->dpll_props.package_label = props->package_label;
+ return;
+ }
+
+ /* The internal INTSYNC source (output) pin has a fixed label */
+ if (dir == DPLL_PIN_DIRECTION_OUTPUT &&
+ id == SIT9531X_INTSYNC_OUT_PIN_ID) {
+ strscpy(props->package_label, "SYNCOUT",
+ sizeof(props->package_label));
+ props->dpll_props.package_label = props->package_label;
+ return;
+ }
+
+ if (dir == DPLL_PIN_DIRECTION_INPUT)
+ sit9531x_input_pin_label(sitdev, props, id);
+ else
+ snprintf(props->package_label, sizeof(props->package_label),
+ "OUT%u", id);
+
+ props->dpll_props.package_label = props->package_label;
+}
+
+/*
+ * sit9531x_prop_pin_fwnode_get - find firmware node for a pin
+ * @dir: pin direction
+ * @id: pin index
+ *
+ * Searches for input-pins/output-pins child nodes in DT, looking
+ * for a child whose "reg" property matches @id.
+ *
+ * Return: 0 on success, -ENOENT if no firmware node exists
+ */
+static int
+sit9531x_prop_pin_fwnode_get(struct sit9531x_dev *sitdev,
+ struct sit9531x_pin_props *props,
+ enum dpll_pin_direction dir, u8 id)
+{
+ struct fwnode_handle *pins_node, *pin_node;
+ const char *node_name;
+
+ if (dir == DPLL_PIN_DIRECTION_INPUT)
+ node_name = "input-pins";
+ else
+ node_name = "output-pins";
+
+ pins_node = device_get_named_child_node(sitdev->dev, node_name);
+ if (!pins_node) {
+ dev_dbg(sitdev->dev, "'%s' sub-node is missing\n", node_name);
+ return -ENOENT;
+ }
+
+ /* Enumerate child pin nodes and find the requested one */
+ fwnode_for_each_child_node(pins_node, pin_node) {
+ u32 reg;
+
+ if (fwnode_property_read_u32(pin_node, "reg", ®))
+ continue;
+
+ if (id == reg)
+ break;
+ }
+
+ fwnode_handle_put(pins_node);
+
+ props->fwnode = pin_node;
+
+ dev_dbg(sitdev->dev, "Firmware node for %s %sfound\n",
+ props->package_label, pin_node ? "" : "NOT ");
+
+ return pin_node ? 0 : -ENOENT;
+}
+
+/*
+ * sit9531x_pin_props_get - get pin properties for a given pin
+ * @dir: pin direction (INPUT or OUTPUT)
+ * @index: pin index
+ *
+ * Allocates a pin properties structure, generates a package label,
+ * looks up the firmware node if available, and reads optional
+ * properties (label, connection-type, supported-frequencies-hz,
+ * esync-control).
+ *
+ * Call sit9531x_pin_props_put() to free the returned structure.
+ *
+ * Return: pointer to pin properties on success, error pointer on error
+ */
+struct sit9531x_pin_props *
+sit9531x_pin_props_get(struct sit9531x_dev *sitdev,
+ enum dpll_pin_direction dir, u8 index)
+{
+ struct dpll_pin_frequency *ranges;
+ struct sit9531x_pin_props *props;
+ int i, j, num_freqs = 0, rc;
+ u64 *freqs = NULL;
+ const char *type;
+ u32 curr_freq;
+
+ props = kzalloc_obj(*props, GFP_KERNEL);
+ if (!props)
+ return ERR_PTR(-ENOMEM);
+
+ if (dir == DPLL_PIN_DIRECTION_INPUT &&
+ index == SIT9531X_INTSYNC_PIN_ID) {
+ /*
+ * INTSYNC destination pin: a PLL locks to the INTSYNC net as a
+ * reference, so it can be connected and re-prioritised.
+ */
+ props->dpll_props.type = DPLL_PIN_TYPE_INT_OSCILLATOR;
+ props->dpll_props.capabilities =
+ DPLL_PIN_CAPABILITIES_PRIORITY_CAN_CHANGE |
+ DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
+ curr_freq = 0;
+ } else if (dir == DPLL_PIN_DIRECTION_OUTPUT &&
+ index == SIT9531X_INTSYNC_OUT_PIN_ID) {
+ /*
+ * INTSYNC source pin: a PLL drives the INTSYNC net. It can be
+ * connected/disconnected but carries no priority (driving the
+ * net is not a reference selection) and no frequency.
+ */
+ props->dpll_props.type = DPLL_PIN_TYPE_INT_OSCILLATOR;
+ props->dpll_props.capabilities =
+ DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
+ curr_freq = 0;
+ } else if (dir == DPLL_PIN_DIRECTION_INPUT &&
+ index == SIT9531X_MAX_INPUTS) {
+ /* The XO reference is fixed: no state or priority control. */
+ props->dpll_props.type = DPLL_PIN_TYPE_INT_OSCILLATOR;
+ props->dpll_props.capabilities = 0;
+ sitdev->ref[index].freq = sitdev->xtal_freq;
+ curr_freq = sitdev->xtal_freq;
+ } else if (dir == DPLL_PIN_DIRECTION_INPUT) {
+ props->dpll_props.type = DPLL_PIN_TYPE_EXT;
+ props->dpll_props.capabilities =
+ DPLL_PIN_CAPABILITIES_PRIORITY_CAN_CHANGE |
+ DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
+ curr_freq = sitdev->ref[index].freq;
+ } else {
+ props->dpll_props.type = DPLL_PIN_TYPE_GNSS;
+ props->dpll_props.capabilities =
+ DPLL_PIN_CAPABILITIES_STATE_CAN_CHANGE;
+ curr_freq = sitdev->out[index].freq;
+ }
+
+ /* Allow phase-adjust over +/-1 ms window. The subsystem rejects
+ * pin_set(phase-adjust, X) when X falls outside [min, max], so
+ * leaving these at 0 silently blocks every netlink call. 1 ms is
+ * well beyond the DCO dynamic range but costs nothing.
+ */
+ props->dpll_props.phase_range.min = -1000000000; /* -1 ms in ps */
+ props->dpll_props.phase_range.max = 1000000000; /* +1 ms in ps */
+
+ /* Generate package label */
+ sit9531x_prop_pin_package_label_set(sitdev, props, dir, index);
+
+ /*
+ * Both INTSYNC pins are internal to the chip and have no board-level
+ * wiring, so they take no properties from the firmware node.
+ */
+ if (dir == DPLL_PIN_DIRECTION_INPUT &&
+ index == SIT9531X_INTSYNC_PIN_ID)
+ goto skip_fwnode_props;
+ if (dir == DPLL_PIN_DIRECTION_OUTPUT &&
+ index == SIT9531X_INTSYNC_OUT_PIN_ID)
+ goto skip_fwnode_props;
+
+ rc = sit9531x_prop_pin_fwnode_get(sitdev, props, dir, index);
+ if (rc)
+ goto skip_fwnode_props;
+
+ /* Look for "label" property -> board label */
+ fwnode_property_read_string(props->fwnode, "label",
+ &props->dpll_props.board_label);
+
+ /* Look for "connection-type" property -> pin type enum */
+ if (!fwnode_property_read_string(props->fwnode, "connection-type",
+ &type)) {
+ if (!strcmp(type, "ext"))
+ props->dpll_props.type = DPLL_PIN_TYPE_EXT;
+ else if (!strcmp(type, "gnss"))
+ props->dpll_props.type = DPLL_PIN_TYPE_GNSS;
+ else if (!strcmp(type, "int") ||
+ !strcmp(type, "int-oscillator"))
+ props->dpll_props.type = DPLL_PIN_TYPE_INT_OSCILLATOR;
+ else if (!strcmp(type, "synce") ||
+ !strcmp(type, "synce-eth-port"))
+ props->dpll_props.type = DPLL_PIN_TYPE_SYNCE_ETH_PORT;
+ else if (!strcmp(type, "mux"))
+ props->dpll_props.type = DPLL_PIN_TYPE_MUX;
+ else
+ dev_warn(sitdev->dev,
+ "Unknown pin type '%s'\n", type);
+ }
+
+ props->esync_control =
+ fwnode_property_read_bool(props->fwnode, "esync-control");
+
+ num_freqs = fwnode_property_count_u64(props->fwnode,
+ "supported-frequencies-hz");
+ if (num_freqs <= 0) {
+ num_freqs = 0;
+ goto skip_fwnode_props;
+ }
+
+ freqs = kcalloc(num_freqs, sizeof(*freqs), GFP_KERNEL);
+ if (!freqs) {
+ rc = -ENOMEM;
+ goto err_alloc_freqs;
+ }
+
+ fwnode_property_read_u64_array(props->fwnode,
+ "supported-frequencies-hz",
+ freqs, num_freqs);
+
+ /*
+ * Seed the runtime ref->freq / out->freq with the first DT-listed
+ * supported frequency so the netlink frequency_get callback reports
+ * a sane initial value before any pin_set occurs. DT lists the
+ * physically-wired reference frequency for each input pin and the
+ * default output frequency for each output pin.
+ */
+ if (num_freqs > 0) {
+ if (dir == DPLL_PIN_DIRECTION_INPUT)
+ sitdev->ref[index].freq = (u32)freqs[0];
+ else
+ sitdev->out[index].freq = (u32)freqs[0];
+ curr_freq = (u32)freqs[0];
+ }
+
+skip_fwnode_props:
+ /* Neither INTSYNC pin carries a frequency attribute */
+ if (dir == DPLL_PIN_DIRECTION_INPUT &&
+ index == SIT9531X_INTSYNC_PIN_ID)
+ return props;
+ if (dir == DPLL_PIN_DIRECTION_OUTPUT &&
+ index == SIT9531X_INTSYNC_OUT_PIN_ID)
+ return props;
+
+ /* Allocate frequency ranges list -- DT discrete entries + current
+ * freq + one catch-all wide range so the subsystem never pre-
+ * rejects a frequency_set call. The chip's real admissible set
+ * is bounded by VCO / divider math in sit9531x_output_freq_set().
+ */
+ ranges = kcalloc(num_freqs + 2, sizeof(*ranges), GFP_KERNEL);
+ if (!ranges) {
+ rc = -ENOMEM;
+ goto err_alloc_ranges;
+ }
+
+ /* Current freq as first entry */
+ ranges[0] = (struct dpll_pin_frequency)DPLL_PIN_FREQUENCY(curr_freq);
+ j = 1;
+
+ for (i = 0; i < num_freqs; i++) {
+ struct dpll_pin_frequency freq = DPLL_PIN_FREQUENCY(freqs[i]);
+
+ if (freqs[i] == curr_freq)
+ continue;
+ ranges[j++] = freq;
+ }
+
+ /* Always append a wide catch-all range */
+ ranges[j].min = 1;
+ ranges[j].max = 1000000000ULL; /* 1 GHz */
+ j++;
+
+ props->dpll_props.freq_supported = ranges;
+ props->dpll_props.freq_supported_num = j;
+
+ kfree(freqs);
+
+ return props;
+
+err_alloc_ranges:
+ kfree(freqs);
+err_alloc_freqs:
+ fwnode_handle_put(props->fwnode);
+ kfree(props);
+
+ return ERR_PTR(rc);
+}
+
+/*
+ * sit9531x_pin_props_put - release pin properties
+ * @props: pin properties to free
+ */
+void sit9531x_pin_props_put(struct sit9531x_pin_props *props)
+{
+ kfree(props->dpll_props.freq_supported);
+
+ if (props->fwnode)
+ fwnode_handle_put(props->fwnode);
+
+ kfree(props);
+}
+
+/*
+ * sit9531x_prop_dpll_type_get - get DPLL channel type from firmware
+ * @index: DPLL channel index (0-3)
+ *
+ * Reads the "dpll-types" string array property from the firmware node
+ * and returns the corresponding DPLL type enum.
+ *
+ * Return: DPLL type for the given channel (default: DPLL_TYPE_PPS)
+ */
+enum dpll_type
+sit9531x_prop_dpll_type_get(struct sit9531x_dev *sitdev, u8 index)
+{
+ const char *types[SIT9531X_NUM_PLLS];
+ int count;
+
+ count = device_property_read_string_array(sitdev->dev, "dpll-types",
+ types, ARRAY_SIZE(types));
+
+ if (index >= count)
+ return DPLL_TYPE_PPS;
+
+ if (!strcmp(types[index], "pps"))
+ return DPLL_TYPE_PPS;
+ else if (!strcmp(types[index], "eec"))
+ return DPLL_TYPE_EEC;
+
+ dev_warn(sitdev->dev, "Unknown DPLL type '%s', using default\n",
+ types[index]);
+
+ return DPLL_TYPE_PPS;
+}
diff --git a/drivers/dpll/sit9531x/prop.h b/drivers/dpll/sit9531x/prop.h
new file mode 100644
index 000000000000..f7f1c854b955
--- /dev/null
+++ b/drivers/dpll/sit9531x/prop.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SiTime SiT9531x firmware node property parsing
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ */
+
+#ifndef _SIT9531X_PROP_H
+#define _SIT9531X_PROP_H
+
+#include <linux/dpll.h>
+#include <linux/fwnode.h>
+
+struct sit9531x_dev;
+
+/*
+ * struct sit9531x_pin_props - pin properties from firmware
+ * @fwnode: firmware node handle (NULL if no DT node)
+ * @dpll_props: DPLL core pin properties
+ * @package_label: pin package label (e.g. "IN0", "OUT3")
+ * @esync_control: embedded sync is controllable
+ */
+struct sit9531x_pin_props {
+ struct fwnode_handle *fwnode;
+ struct dpll_pin_properties dpll_props;
+ char package_label[8];
+ bool esync_control;
+};
+
+enum dpll_type sit9531x_prop_dpll_type_get(struct sit9531x_dev *sitdev,
+ u8 index);
+struct sit9531x_pin_props *sit9531x_pin_props_get(struct sit9531x_dev *sitdev,
+ enum dpll_pin_direction dir,
+ u8 index);
+void sit9531x_pin_props_put(struct sit9531x_pin_props *props);
+
+#endif /* _SIT9531X_PROP_H */
diff --git a/drivers/dpll/sit9531x/regs.h b/drivers/dpll/sit9531x/regs.h
new file mode 100644
index 000000000000..5c3dbeefd86b
--- /dev/null
+++ b/drivers/dpll/sit9531x/regs.h
@@ -0,0 +1,371 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * SiTime SiT9531x register definitions
+ *
+ * Copyright (C) 2026 SiTime Corp.
+ * Author: Ali Rouhi <arouhi@sitime.com>
+ * Author: Oleg Zadorozhnyi <Oleg.Zadorozhnyi@devoxsoftware.com>
+ */
+
+#ifndef _SIT9531X_REGS_H
+#define _SIT9531X_REGS_H
+
+/*
+ * I2C register model:
+ * - Page select register at offset 0x01
+ * - Each page has 128 registers (0x00-0x7F)
+ * - Some pages are paired (e.g. 0x0A/0x1A for PLLA)
+ */
+#define SIT9531X_PAGE_SEL 0xFF
+#define SIT9531X_PAGE_SIZE 0x100
+#define SIT9531X_NUM_PAGES 32
+
+/* Helper macros for page:offset addressing */
+#define SIT9531X_REG(_page, _offset) (((_page) << 8) | (_offset))
+#define SIT9531X_REG_PAGE(_reg) ((_reg) >> 8)
+#define SIT9531X_REG_OFFSET(_reg) ((_reg) & 0xFF)
+
+/* ---- Page definitions ---- */
+#define SIT9531X_PAGE_MAINSYS0 0x00
+#define SIT9531X_PAGE_MAINSYS1 0x01
+#define SIT9531X_PAGE_INPUTSYS 0x02
+#define SIT9531X_PAGE_OUTSYS0 0x03
+#define SIT9531X_PAGE_OUTSYS1 0x04
+#define SIT9531X_PAGE_CLKMON0 0x06
+#define SIT9531X_PAGE_CLKMON1 0x07
+#define SIT9531X_PAGE_PLLA 0x0A
+#define SIT9531X_PAGE_PLLA_EXT 0x1A
+#define SIT9531X_PAGE_PLLB 0x0B
+#define SIT9531X_PAGE_PLLB_EXT 0x1B
+#define SIT9531X_PAGE_PLLC 0x0C
+#define SIT9531X_PAGE_PLLC_EXT 0x1C
+#define SIT9531X_PAGE_PLLD 0x0D
+#define SIT9531X_PAGE_PLLD_EXT 0x1D
+
+/* PLL index to page mapping */
+#define SIT9531X_PLL_PAGE(_idx) \
+ (SIT9531X_PAGE_PLLA + (_idx))
+
+/*
+ * VARIANT_ID is a single byte at page 0 reg 0x02 (95317 = 0x17, 95316 = 0x31).
+ * Reg 0x03 carries an unrelated revision byte and must not be combined into
+ * the variant identifier.
+ */
+#define SIT9531X_REG_VARIANT_ID SIT9531X_REG(0x00, 0x02)
+
+/* DCO trigger pulse timing: minimum 6 ns required by hardware */
+
+#define SIT9531X_REG_HOLDOVER_HISTORY SIT9531X_REG(0x00, 0x58)
+
+/* Page 0 -- PLL inner loop loss-of-lock */
+#define SIT9531X_REG_PLL_INNER_LOL_STATUS SIT9531X_REG(0x00, 0x92)
+#define SIT9531X_REG_PLL_INNER_LOL_NOTIF SIT9531X_REG(0x00, 0x93)
+
+/* Page 0 -- Clock monitor PLL / XO status */
+#define SIT9531X_REG_CMON_NOTIF SIT9531X_REG(0x00, 0x9E)
+
+/* Page 0 -- PLL outer-loop loss-of-lock */
+#define SIT9531X_REG_OUTER_LOL_STATUS SIT9531X_REG(0x00, 0x06)
+#define SIT9531X_REG_OUTER_LOL_NOTIF SIT9531X_REG(0x00, 0x07)
+
+/* Page 0 -- PLL holdover freeze status */
+#define SIT9531X_REG_HO_FREEZE_STATUS SIT9531X_REG(0x00, 0x0A)
+#define SIT9531X_REG_HO_FREEZE_NOTIF SIT9531X_REG(0x00, 0x0B)
+
+/* Page 0 -- INTSYNC (inter-PLL synchronization) global enable */
+#define SIT9531X_REG_INTSYNC_GLOBAL SIT9531X_REG(0x00, 0x40)
+#define SIT9531X_INTSYNC_EN_BIT 6
+
+/*
+ * Priority table: 6 registers per PLL, each holds two priority slots
+ * nibble-packed. The register holding slots 2n and 2n+1 keeps the
+ * earlier slot (CLK_SPARE<2n>SEL_PLL) in [7:4] and the later one in
+ * [3:0].
+ *
+ * Base registers for PLLA: 0x16-0x1B (slots 0-10 plus the
+ * active-reference nibble).
+ * For PLL N: base + 6 * N (e.g. PLLB starts at 0x1C).
+ *
+ * Input source encoding (4-bit value):
+ * 0=IN0P, 1=IN1P, 2=IN2P, 3=IN3P, 4=IN4P,
+ * 5=OCXO, 6=INTSYNC,
+ * 7=IN0N, 8=IN1N, 9=IN2N, 10=IN3N, 11=IN4N
+ */
+#define SIT9531X_PAGE_PRIOSYS 0x01
+#define SIT9531X_PRIO_BASE_REG 0x16
+#define SIT9531X_PRIO_REGS_PER_PLL 6
+#define SIT9531X_PRIO_SLOTS_PER_REG 2
+/*
+ * 11 priority slots, CLK_SPARE0SEL_PLL through CLK_SPARE10SEL_PLL.
+ * The twelfth nibble of the block is not a slot: it is
+ * CLK_ACTIVESEL_PLL, see SIT9531X_PRIO_ACTIVESEL_OFF below.
+ */
+#define SIT9531X_PRIO_MAX_SLOTS 11
+/* Number of source encodings (0-11), unrelated to the slot count */
+#define SIT9531X_PRIO_NUM_SRC 12
+#define SIT9531X_PRIO_NIBBLE_MASK 0x0F
+#define SIT9531X_PRIO_HI_SHIFT 4
+/* Input source encoding values (see table above) */
+#define SIT9531X_PRIO_SRC_OCXO 5
+#define SIT9531X_PRIO_SRC_INTSYNC 6
+#define SIT9531X_PRIO_SRC_N_BASE 7
+/*
+ * The last register of each PLL's priority block holds, in its low
+ * nibble, the input source the PLL has currently selected as its
+ * active reference (CLK_ACTIVESEL_PLL, same 4-bit encoding as above).
+ */
+#define SIT9531X_PRIO_ACTIVESEL_OFF 5
+
+/*
+ * Page 0 -- PRG_Directives_GENERIC_0, the main system's programming
+ * directive register. Every page carries its own copy of this
+ * register at offset 0x0F with the same bit layout:
+ *
+ * bit 6 proceed to loop lock / active state from the PRG_CMD state
+ * bit 4 update the NVM bank from the efuse contents
+ * bit 3 read the efuse
+ * bit 2 program the efuse
+ * bit 1 small change update (SIT9531X_SMALL_UPDATE_CMD)
+ * bit 0 escape to the PRG_CMD state
+ *
+ * Only the small change update belongs in a runtime path; the efuse
+ * and NVM directives touch non-volatile storage.
+ */
+#define SIT9531X_REG_GLOBAL_UPDATE SIT9531X_REG(0x00, 0x0F)
+#define SIT9531X_SMALL_UPDATE_CMD 0x02
+
+/* PLL holdover control (PLL page offset) */
+#define SIT9531X_PLL_REG_HO_CTRL 0x6F
+#define SIT9531X_PLL_HO_FORCE_BIT 4
+
+/* One bit per input PAIR (bit 0 = CLKIN0, ..., bit 3 = CLKIN3) */
+#define SIT9531X_REG_IN_DE_FORCE SIT9531X_REG(0x02, 0xE8)
+#define SIT9531X_REG_IN_DE_STATE SIT9531X_REG(0x02, 0xE9)
+#define SIT9531X_REG_IN_SEP_FORCE SIT9531X_REG(0x02, 0xEA)
+#define SIT9531X_REG_IN_SEP_STATE SIT9531X_REG(0x02, 0xEB)
+#define SIT9531X_REG_IN_SEN_FORCE SIT9531X_REG(0x02, 0xF2)
+#define SIT9531X_REG_IN_SEN_STATE SIT9531X_REG(0x02, 0xF3)
+
+/*
+ * One register per input pair at 0x1B + 0x10 * pair
+ * (CLKIN0 = 0x1B, CLKIN1 = 0x2B, CLKIN2 = 0x3B, CLKIN3 = 0x4B).
+ * SE_P_EN/SE_N_EN set means the corresponding lane is configured
+ * single-ended; both clear means the pair runs differential.
+ */
+#define SIT9531X_REG_IN_MODE(_pair) \
+ SIT9531X_REG(0x02, 0x1B + 0x10 * (_pair))
+#define SIT9531X_IN_MODE_SE_P_EN BIT(0)
+#define SIT9531X_IN_MODE_SE_N_EN BIT(1)
+
+/* ---- Page 0x03 (Output System) registers -- Hi-Z control ---- */
+#define SIT9531X_REG_HIZ_DIFF_07_MASK SIT9531X_REG(0x03, 0xF2)
+#define SIT9531X_REG_HIZ_DIFF_07_STATE SIT9531X_REG(0x03, 0xF3)
+#define SIT9531X_REG_HIZ_DIFF_811_MASK SIT9531X_REG(0x03, 0xF4)
+#define SIT9531X_REG_HIZ_DIFF_811_STATE SIT9531X_REG(0x03, 0xF5)
+#define SIT9531X_REG_HIZ_SE_07_MASK SIT9531X_REG(0x03, 0xF8)
+#define SIT9531X_REG_HIZ_SE_07_STATE SIT9531X_REG(0x03, 0xF9)
+#define SIT9531X_REG_HIZ_SE_811_MASK SIT9531X_REG(0x03, 0xFA)
+#define SIT9531X_REG_HIZ_SE_811_STATE SIT9531X_REG(0x03, 0xFB)
+
+/*
+ * Output divider registers in Pages 3/4. Each output has a 34-bit
+ * integer divider mapped to 5 bytes (LSB at base reg, MSB at base-4).
+ * Outputs 0-5 are on Page 3, outputs 6-11 are on Page 4.
+ *
+ * The base register for slot N within a page is:
+ * clkout_odr_divn_base[slot] = { 0x14, 0x24, 0x34, 0x44, 0x54, 0x64 }
+ *
+ * Layout: base=LSB, base-1, base-2, base-3, base-4[1:0]=MSB.
+ *
+ * Per-chip clkout_map[] translates output index to slot position.
+ */
+#define SIT9531X_PAGE_OUTSYS0_SLOT_MAX 5 /* slots 0-5 on Page 0x03 */
+
+/* Misc output system registers */
+#define SIT9531X_REG_PRG_DIR_GEN SIT9531X_REG(0x03, 0x0F)
+#define SIT9531X_PRG_CMD_STATE 0x01
+#define SIT9531X_UPDATE_NVM 0x10
+#define SIT9531X_LOOP_LOCK 0x40
+
+/* Debug register (same offset, per-page) */
+#define SIT9531X_REG_OUTSYS_DEBUG SIT9531X_REG(0x03, 0xBD)
+#define SIT9531X_DEBUG_UNLOCK_VAL 0xC3
+
+/*
+ * Per-output programmable phase delay: 34-bit coarse (in VCO clock
+ * cycles) plus a 3-bit fine field with fixed 30 ps steps. Each output
+ * has a five-byte block PROG6..PROG2:
+ *
+ * base + 0 PROG6 [7:5] OPSTG_VCASC_BUMP (preserve via RMW)
+ * [4:2] PRG_RST_FINE_DELAY[2:0]
+ * [1:0] PRG_RST_DELAY[33:32]
+ * base + 1 PROG5 [7:0] PRG_RST_DELAY[31:24]
+ * base + 2 PROG4 [7:0] PRG_RST_DELAY[23:16]
+ * base + 3 PROG3 [7:0] PRG_RST_DELAY[15:8]
+ * base + 4 PROG2 [7:0] PRG_RST_DELAY[7:0]
+ *
+ * Outputs 0-5 are on Page 3, outputs 6-11 on Page 4. The block base
+ * within a page is 0x15 + 16 * (out_idx % 6).
+ */
+#define SIT9531X_OUT_PRG_DELAY_BASE 0x15
+#define SIT9531X_OUT_PRG_SLOT_STRIDE 0x10
+#define SIT9531X_OUT_PRG_OPSTG_MASK 0xE0 /* bits [7:5], preserve */
+#define SIT9531X_OUT_PRG_FINE_SHIFT 2
+#define SIT9531X_OUT_PRG_FINE_MASK 0x1C /* bits [4:2] */
+#define SIT9531X_OUT_PRG_COARSE_HI_MASK 0x03 /* bits [1:0] */
+#define SIT9531X_OUT_PRG_FINE_STEP_PS 30
+#define SIT9531X_OUT_PRG_FINE_MAX 7 /* 3-bit field */
+#define SIT9531X_OUT_PRG_COARSE_BITS 34
+
+/*
+ * Per-output pulse-count control byte used in SYSREF / SYNCB modes.
+ * Slot N within a page sits at 0x1B + 16 * (slot % 6). Same page
+ * mapping as PRG_RST_DELAY: slots 0-5 on Page 3, slots 6-11 on Page 4.
+ */
+#define SIT9531X_OUT_PROG0_BASE 0x1B
+
+/*
+ * On-demand phase-flush fired from a register rather than a GPIO pin.
+ * DIVO_PHASE_SEL_REG selects the in-register trigger source and
+ * DIVO_PHASE_TRIG flushes the output phase when pulsed high then low.
+ * The unrelated OEb trigger pair in bits [7:6] must be preserved.
+ */
+#define SIT9531X_REG_GPIO_FUNC_CTRL1 SIT9531X_REG(0x00, 0x65)
+#define SIT9531X_DIVO_PHASE_SEL_REG BIT(5)
+#define SIT9531X_DIVO_PHASE_TRIG BIT(4)
+
+/* ---- PLL page registers (apply to pages 0x0A-0x0D) ---- */
+#define SIT9531X_PLL_REG_SMALL_UPDATE 0x0F
+
+/* On-demand phase-flush enable (PLL page reg 0x3D bit 7) */
+#define SIT9531X_PLL_REG_PHFL_CTRL 0x3D
+#define SIT9531X_PLL_PHFL_ON_DEMAND_EN BIT(7)
+
+/*
+ * Loop-filter coefficients on PLL_PAGE regs 0x10-0x15 (3 normal +
+ * 3 fast-lock) are GUI/NVM-generated by the timing configurator and must not be
+ * reprogrammed at runtime; the register map flags them as
+ * "GUI generated configuration should not change manually".
+ */
+
+#define SIT9531X_PLL_REG_OUT_MAP_HI 0x27
+#define SIT9531X_PLL_REG_OUT_MAP_LO 0x28
+#define SIT9531X_PLL_REG_STATUS 0x31
+#define SIT9531X_PLL_REG_NVM_UPDATE 0x3F
+
+/* DIVN registers (free-run divider readback) */
+#define SIT9531X_PLL_REG_DIVN_INT 0x30
+#define SIT9531X_PLL_REG_DIVN_NUM 0x32 /* 4 bytes (0x32-0x35) */
+#define SIT9531X_PLL_REG_DIVN_DEN 0x38 /* 4 bytes (0x38-0x3B) */
+
+/* DIVN2 registers (sync divider readback) */
+#define SIT9531X_PLL_REG_DIVN2_INT 0x3E /* 5 bytes (0x3E-0x42) */
+#define SIT9531X_PLL_REG_DIVN2_FRAC_NUM 0x43 /* 4 bytes (0x43-0x46) */
+#define SIT9531X_PLL_REG_DIVN2_FRAC_DEN 0x49 /* 4 bytes (0x49-0x4C) */
+
+/* Debug register unlock */
+#define SIT9531X_PLL_REG_DEBUG 0xBD
+#define SIT9531X_PLL_DEBUG_UNLOCK 0xC3
+
+/*
+ * Signal pathway debug readback -- PLL page. Dig_Sys_ReadCode selects
+ * which point of the pathway is tapped, Dig_Sys_WriteCode carries the
+ * modifiers for that read, Dig_Sys_read7..read0 hold the sampled bytes
+ * and the trigger register latches a sample. The TDC phase
+ * measurement is one tap among several, reached through read code 69.
+ */
+#define SIT9531X_PLL_REG_DBG_READ_CODE 0xB3
+#define SIT9531X_PLL_REG_DBG_WRITE_CODE 0xB4
+#define SIT9531X_DBG_LOW_FREQ_CLK_BIT BIT(7)
+#define SIT9531X_PLL_REG_DBG_DATA_0 0xB5 /* [7:0] */
+#define SIT9531X_PLL_REG_DBG_DATA_1 0xB6 /* [15:8] */
+#define SIT9531X_PLL_REG_DBG_DATA_2 0xB7 /* [23:16] */
+#define SIT9531X_PLL_REG_DBG_DATA_3 0xB8 /* [31:24] */
+#define SIT9531X_PLL_REG_DBG_DATA_4 0xB9 /* [39:32] + sign */
+#define SIT9531X_PLL_REG_DBG_DATA_5 0xBA /* [47:40] */
+#define SIT9531X_PLL_REG_DBG_DATA_6 0xBB
+#define SIT9531X_PLL_REG_DBG_DATA_7 0xBC
+#define SIT9531X_PLL_REG_DBG_TRIGGER 0xD0 /* read to latch a sample */
+#define SIT9531X_DBG_DATA_BYTES 8
+
+/* Read code of the TDC phase tap, and the sign bit of its sample */
+#define SIT9531X_DBG_READ_CODE_TDC 69
+#define SIT9531X_TDC_SIGN_BIT 3
+
+/*
+ * Read codes of the running DIVN taps. Unlike the configuration
+ * registers these report what the digital loop currently commands, so
+ * they carry the correction the loop applies to track its reference.
+ * The integer part and the numerator share one tap, the denominator
+ * has its own.
+ */
+#define SIT9531X_DBG_READ_CODE_DIVN 0x57
+#define SIT9531X_DBG_READ_CODE_DIVN_DEN 0x56
+#define SIT9531X_DIVN_RT_NUM_BITS 48
+#define SIT9531X_DIVN_RT_INT_HI_BIT BIT(0)
+
+/*
+ * DIVN carried as fixed point, and the unit the DPLL ABI wants the
+ * fractional frequency offset in. Equal in value, distinct in meaning.
+ */
+#define SIT9531X_DIVN_SCALE 1000000000000ULL
+#define SIT9531X_PPT_PER_UNIT 1000000000000ULL
+
+/*
+ * TDC phase-difference measurement setup (PLL page). Per the vendor
+ * PhaseDifferenceReader reference procedure, a valid TDC reading needs
+ * the digital loop filter frozen (so the VCO does not track out the
+ * measured offset mid-sample) and, on PLLA (the 1PPS phase DPLL), the
+ * automatic phase/frequency-lock helpers held off.
+ */
+#define SIT9531X_PLL_REG_DLPF_FREEZE0 0x8A
+#define SIT9531X_PLL_REG_DLPF_FREEZE1 0x8B
+#define SIT9531X_PLL_DLPF_FREEZE_BIT BIT(5) /* freeze DLPF (hitless HO) */
+#define SIT9531X_PLL_REG_APL_CTRL 0x4D
+#define SIT9531X_PLL_APL_WAKEUP_DIS_BIT BIT(7) /* disable APL at wake-up */
+#define SIT9531X_PLL_APL_SWITCH_EN_BIT BIT(5) /* APL on switchover */
+#define SIT9531X_PLL_REG_AFL_CTRL 0x4E
+#define SIT9531X_PLL_AFL_WAKEUP_DIS_BIT BIT(5) /* disable AFL at wake-up */
+#define SIT9531X_PLL_CONFIG47_PHFL_BIT BIT(7) /* PHFL enable (reg 0x47) */
+#define SIT9531X_PLL_REG_ACTIVE 0x02
+#define SIT9531X_PLL_ACTIVE_BIT BIT(0) /* PLL reached active state */
+#define SIT9531X_PLL_REG_RESTART 0x05
+#define SIT9531X_PLL_RESTART_BIT BIT(0) /* restart the PLL */
+#define SIT9531X_PLL_REG_ZDB0 0x2B
+#define SIT9531X_PLL_REG_ZDB1 0x1E
+#define SIT9531X_PLL_ZDB_EN_BIT BIT(4) /* zero-delay buffer enabled */
+
+/* PLL EXT page INTSYNC configuration registers */
+#define SIT9531X_PLL_EXT_PAGE(_idx) (SIT9531X_PAGE_PLLA_EXT + (_idx))
+
+/* PLL STATUS register bits */
+#define SIT9531X_PLL_STATUS_LOCK BIT(0)
+#define SIT9531X_PLL_STATUS_OUTER_DIS BIT(5)
+
+/* P-polarity status registers */
+#define SIT9531X_CLKMON_P_STATUS_01 SIT9531X_REG(0x06, 0x02) /* inputs 0,1 */
+#define SIT9531X_CLKMON_P_NOTIF_01 SIT9531X_REG(0x06, 0x03)
+#define SIT9531X_CLKMON_P_STATUS_23 SIT9531X_REG(0x06, 0x06) /* inputs 2,3 */
+#define SIT9531X_CLKMON_P_NOTIF_23 SIT9531X_REG(0x06, 0x07)
+
+/* N-polarity status registers */
+#define SIT9531X_CLKMON_N_STATUS_01 SIT9531X_REG(0x06, 0x92) /* inputs 0,1 */
+#define SIT9531X_CLKMON_N_NOTIF_01 SIT9531X_REG(0x06, 0x93)
+#define SIT9531X_CLKMON_N_STATUS_23 SIT9531X_REG(0x06, 0x96) /* inputs 2,3 */
+#define SIT9531X_CLKMON_N_NOTIF_23 SIT9531X_REG(0x06, 0x97)
+
+/* Per-input bit offsets within clock monitor nibble */
+#define SIT9531X_CLKMON_FREQ_FINE 0 /* bit 0 / bit 4 */
+#define SIT9531X_CLKMON_FREQ_COARSE 1 /* bit 1 / bit 5 */
+#define SIT9531X_CLKMON_CLK_LOSS 2 /* bit 2 / bit 6 */
+#define SIT9531X_CLKMON_CLK_LOSS_FD 3 /* bit 3 / bit 7 */
+
+/* ---- Debug / NVM unlock registers ---- */
+#define SIT9531X_REG_DBG_UNLOCK1 0x24
+#define SIT9531X_REG_DBG_UNLOCK2 0x25
+
+/* ---- Variant ID values (single byte read from SIT9531X_REG_VARIANT_ID) ---- */
+#define SIT9531X_VARIANT_ID_95317 0x17
+#define SIT9531X_VARIANT_ID_95316 0x31
+
+#endif /* _SIT9531X_REGS_H */
--
2.34.1
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