[RFC v3 03/12] hte: Add tegra194 HTE kernel provider

Dipen Patel
2021-11-23T19:29:50Z

Tegra194 device has multiple HTE instances also known as GTE
(Generic hardware Timestamping Engine) which can timestamp subset of
SoC lines/signals. This provider driver focuses on IRQ and GPIO lines
and exposes timestamping ability on those lines to the consumers
through HTE subsystem.

Also, with this patch, added:
- documentation about this provider and its capabilities at
Documentation/hte.
- Compilation support in Makefile and Kconfig

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
---
Changes in v3:
- Addressed grammatical/spelling errors.

Documentation/hte/index.rst | 22 ++
Documentation/hte/tegra194-hte.rst | 57 +++
Documentation/index.rst | 1 +
drivers/hte/Kconfig | 12 +
drivers/hte/Makefile | 1 +
drivers/hte/hte-tegra194.c | 545 +++++++++++++++++++++++++++++
6 files changed, 638 insertions(+)
create mode 100644 Documentation/hte/index.rst
create mode 100644 Documentation/hte/tegra194-hte.rst
create mode 100644 drivers/hte/hte-tegra194.c

diff --git a/Documentation/hte/index.rst b/Documentation/hte/index.rst
new file mode 100644
index 000000000000..9f43301c05dc
--- /dev/null
+++ b/Documentation/hte/index.rst
@@ -0,0 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================================
+The Linux Hardware Timestamping Engine (HTE)
+============================================
+
+The HTE Subsystem
+=================
+
+.. toctree::
+ :maxdepth: 1
+
+ hte
+
+HTE Tegra Provider
+==================
+
+.. toctree::
+ :maxdepth: 1
+
+ tegra194-hte
+
diff --git a/Documentation/hte/tegra194-hte.rst b/Documentation/hte/tegra194-hte.rst
new file mode 100644
index 000000000000..3bebcbac5847
--- /dev/null
+++ b/Documentation/hte/tegra194-hte.rst
@@ -0,0 +1,57 @@
+HTE Kernel provider driver
+==========================
+
+Description
+-----------
+The Nvidia tegra194 HTE provider driver implements two GTE
+(Generic Timestamping Engine) instances: 1) GPIO GTE and 2) LIC
+(Legacy Interrupt Controller) IRQ GTE. Both GTEs instances get the
+timestamp from the system counter TSC which has 31.25MHz clock rate, and the
+driver converts clock tick rate to nanoseconds before storing it as timestamp
+value.
+
+GPIO GTE
+--------
+
+This GTE instance timestamps GPIO in real time. For that to happen GPIO
+needs to be configured as input and IRQ needs to be enabled. The only always on
+(AON) GPIO controller instance supports timestamping GPIOs in real time and it
+has 39 GPIO lines. The GPIO GTE and AON GPIO controller are tightly coupled as
+it requires very specific bits to be set in GPIO config register before GPIO
+GTE can be used. The GPIO GTE functionality is accessed from the GPIOLIB
+framework for the in-kernel and userspace consumers. In the latter case,
+requests go through GPIOLIB CDEV framework. The below APIs are added in GPIOLIB
+framework to access HTE subsystem and GPIO GTE.
+
+.. kernel-doc:: drivers/gpio/gpiolib.c
+ :functions: gpiod_req_hw_timestamp_ns gpiod_rel_hw_timestamp_ns
+
+There is hte-tegra194-gpio-test.c, located in ``drivers/hte/`` directory, test
+driver which demonstrates above APIs for the Jetson AGX platform.
+
+For userspace consumers, GPIO_V2_LINE_FLAG_EVENT_CLOCK_HARDWARE flag must be
+specified during IOCTL calls. Refer to ``tools/gpio/gpio-event-mon.c``, which
+returns the timestamp in nanoseconds.
+
+LIC (Legacy Interrupt Controller) IRQ GTE
+-----------------------------------------
+
+This GTE instance timestamps LIC IRQ lines in real time. There are 352 IRQ
+lines which this instance can add timestamps to in real time. The hte
+devicetree binding described at ``Documentation/devicetree/bindings/hte/``
+provides an example of how a consumer can request an IRQ line. Since it is a
+one-to-one mapping, consumers can simply specify the IRQ number that they are
+interested in. There is no userspace consumer support for this GTE instance in
+the hte framework. The sample test code hte-tegra194-irq-test.c, located in
+the ``drivers/hte/`` directory, demonstrates how to use an IRQ GTE instance.
+The below is sample device tree snippet code for the test driver::
+
+ tegra_hte_irq_test {
+ compatible = "nvidia,tegra194-hte-irq-test";
+ htes = <&tegra_hte_lic 0x19>;
+ hte-names = "hte-lic";
+ };
+
+The provider source code of both IRQ and GPIO GTE instances is located at
+``drivers/hte/hte-tegra194.c``.
+
diff --git a/Documentation/index.rst b/Documentation/index.rst
index 1b13c2445e87..b41118577fe6 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -138,6 +138,7 @@ needed).
misc-devices/index
scheduler/index
mhi/index
+ hte/index

Architecture-agnostic documentation
-----------------------------------
diff --git a/drivers/hte/Kconfig b/drivers/hte/Kconfig
index 1fcfe17cf28a..ebd9817651c2 100644
--- a/drivers/hte/Kconfig
+++ b/drivers/hte/Kconfig
@@ -20,3 +20,15 @@ menuconfig HTE

If unsure, say no.

+if HTE
+
+config HTE_TEGRA194
+ tristate "NVIDIA Tegra194 HTE Support"
+ depends on ARCH_TEGRA_194_SOC
+ help
+ Enable this option for integrated hardware timestamping engine also
+ known as generic timestamping engine (GTE) support on NVIDIA Tegra194
+ systems-on-chip. The driver supports 352 LIC IRQs and 39 AON GPIOs
+ lines for timestamping in realtime.
+
+endif
diff --git a/drivers/hte/Makefile b/drivers/hte/Makefile
index fc03bdf44427..3ae7c4029991 100644
--- a/drivers/hte/Makefile
+++ b/drivers/hte/Makefile
@@ -1,2 +1,3 @@
obj-$(CONFIG_HTE) += hte.o
+obj-$(CONFIG_HTE_TEGRA194) += hte-tegra194.o

diff --git a/drivers/hte/hte-tegra194.c b/drivers/hte/hte-tegra194.c
new file mode 100644
index 000000000000..ffe9d0d20b94
--- /dev/null
+++ b/drivers/hte/hte-tegra194.c
@@ -0,0 +1,545 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 NVIDIA Corporation
+ *
+ * Author: Dipen Patel <dipenp@nvidia.com>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/hte.h>
+#include <linux/uaccess.h>
+
+#define HTE_SUSPEND 0
+
+/* HTE source clock TSC is 31.25MHz */
+#define HTE_TS_CLK_RATE_HZ 31250000ULL
+#define HTE_CLK_RATE_NS 32
+#define HTE_TS_NS_SHIFT __builtin_ctz(HTE_CLK_RATE_NS)
+
+#define NV_AON_SLICE_INVALID -1
+#define NV_LINES_IN_SLICE 32
+
+/* AON HTE line map For slice 1 */
+#define NV_AON_HTE_SLICE1_IRQ_GPIO_28 12
+#define NV_AON_HTE_SLICE1_IRQ_GPIO_29 13
+
+/* AON HTE line map For slice 2 */
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_0 0
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_1 1
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_2 2
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_3 3
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_4 4
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_5 5
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_6 6
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_7 7
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_8 8
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_9 9
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_10 10
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_11 11
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_12 12
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_13 13
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_14 14
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_15 15
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_16 16
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_17 17
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_18 18
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_19 19
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_20 20
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_21 21
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_22 22
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_23 23
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_24 24
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_25 25
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_26 26
+#define NV_AON_HTE_SLICE2_IRQ_GPIO_27 27
+
+/* AON GPIO port AA pins */
+#define NV_AON_GPIO_PORT_AA_0 0
+#define NV_AON_GPIO_PORT_AA_1 1
+#define NV_AON_GPIO_PORT_AA_2 2
+#define NV_AON_GPIO_PORT_AA_3 3
+#define NV_AON_GPIO_PORT_AA_4 4
+#define NV_AON_GPIO_PORT_AA_5 5
+#define NV_AON_GPIO_PORT_AA_6 6
+#define NV_AON_GPIO_PORT_AA_7 7
+
+/* AON GPIO port BB pins */
+#define NV_AON_GPIO_PORT_BB_0 8
+#define NV_AON_GPIO_PORT_BB_1 9
+#define NV_AON_GPIO_PORT_BB_2 10
+#define NV_AON_GPIO_PORT_BB_3 11
+
+/* AON GPIO port CC pins */
+#define NV_AON_GPIO_PORT_CC_0 12
+#define NV_AON_GPIO_PORT_CC_1 13
+#define NV_AON_GPIO_PORT_CC_2 14
+#define NV_AON_GPIO_PORT_CC_3 15
+#define NV_AON_GPIO_PORT_CC_4 16
+#define NV_AON_GPIO_PORT_CC_5 17
+#define NV_AON_GPIO_PORT_CC_6 18
+#define NV_AON_GPIO_PORT_CC_7 19
+
+/* AON GPIO port DD pins */
+#define NV_AON_GPIO_PORT_DD_0 20
+#define NV_AON_GPIO_PORT_DD_1 21
+#define NV_AON_GPIO_PORT_DD_2 22
+
+/* AON GPIO port EE pins */
+#define NV_AON_GPIO_PORT_EE_0 23
+#define NV_AON_GPIO_PORT_EE_1 24
+#define NV_AON_GPIO_PORT_EE_2 25
+#define NV_AON_GPIO_PORT_EE_3 26
+#define NV_AON_GPIO_PORT_EE_4 27
+#define NV_AON_GPIO_PORT_EE_5 28
+#define NV_AON_GPIO_PORT_EE_6 29
+
+
+#define HTE_TECTRL 0x0
+#define HTE_TETSCH 0x4
+#define HTE_TETSCL 0x8
+#define HTE_TESRC 0xC
+#define HTE_TECCV 0x10
+#define HTE_TEPCV 0x14
+#define HTE_TECMD 0x1C
+#define HTE_TESTATUS 0x20
+#define HTE_SLICE0_TETEN 0x40
+#define HTE_SLICE1_TETEN 0x60
+
+#define HTE_SLICE_SIZE (HTE_SLICE1_TETEN - HTE_SLICE0_TETEN)
+
+#define HTE_TECTRL_ENABLE_ENABLE 0x1
+
+#define HTE_TECTRL_OCCU_SHIFT 0x8
+#define HTE_TECTRL_INTR_SHIFT 0x1
+#define HTE_TECTRL_INTR_ENABLE 0x1
+
+#define HTE_TESRC_SLICE_SHIFT 16
+#define HTE_TESRC_SLICE_DEFAULT_MASK 0xFF
+
+#define HTE_TECMD_CMD_POP 0x1
+
+#define HTE_TESTATUS_OCCUPANCY_SHIFT 8
+#define HTE_TESTATUS_OCCUPANCY_MASK 0xFF
+
+struct hte_slices {
+ u32 r_val;
+ unsigned long flags;
+ /* to prevent lines mapped to same slice updating its register */
+ spinlock_t s_lock;
+};
+
+struct tegra_hte_line_mapped {
+ int slice;
+ u32 bit_index;
+};
+
+struct tegra_hte_line_table {
+ u32 map_sz;
+ const struct tegra_hte_line_mapped *map;
+};
+
+struct tegra_hte_soc {
+ int hte_irq;
+ u32 itr_thrshld;
+ u32 conf_rval;
+ struct hte_slices *sl;
+ const struct tegra_hte_line_table *line_map;
+ struct hte_chip *chip;
+ void __iomem *regs;
+};
+
+static const struct tegra_hte_line_mapped tegra194_aon_gpio_map[] = {
+ /* gpio, slice, bit_index */
+ [NV_AON_GPIO_PORT_AA_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_11},
+ [NV_AON_GPIO_PORT_AA_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_10},
+ [NV_AON_GPIO_PORT_AA_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_9},
+ [NV_AON_GPIO_PORT_AA_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_8},
+ [NV_AON_GPIO_PORT_AA_4] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_7},
+ [NV_AON_GPIO_PORT_AA_5] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_6},
+ [NV_AON_GPIO_PORT_AA_6] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_5},
+ [NV_AON_GPIO_PORT_AA_7] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_4},
+ [NV_AON_GPIO_PORT_BB_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_3},
+ [NV_AON_GPIO_PORT_BB_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_2},
+ [NV_AON_GPIO_PORT_BB_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_1},
+ [NV_AON_GPIO_PORT_BB_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_0},
+ [NV_AON_GPIO_PORT_CC_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_22},
+ [NV_AON_GPIO_PORT_CC_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_21},
+ [NV_AON_GPIO_PORT_CC_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_20},
+ [NV_AON_GPIO_PORT_CC_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_19},
+ [NV_AON_GPIO_PORT_CC_4] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_18},
+ [NV_AON_GPIO_PORT_CC_5] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_17},
+ [NV_AON_GPIO_PORT_CC_6] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_16},
+ [NV_AON_GPIO_PORT_CC_7] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_15},
+ [NV_AON_GPIO_PORT_DD_0] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_14},
+ [NV_AON_GPIO_PORT_DD_1] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_13},
+ [NV_AON_GPIO_PORT_DD_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_12},
+ [NV_AON_GPIO_PORT_EE_0] = {1, NV_AON_HTE_SLICE1_IRQ_GPIO_29},
+ [NV_AON_GPIO_PORT_EE_1] = {1, NV_AON_HTE_SLICE1_IRQ_GPIO_28},
+ [NV_AON_GPIO_PORT_EE_2] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_27},
+ [NV_AON_GPIO_PORT_EE_3] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_26},
+ [NV_AON_GPIO_PORT_EE_4] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_25},
+ [NV_AON_GPIO_PORT_EE_5] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_24},
+ [NV_AON_GPIO_PORT_EE_6] = {2, NV_AON_HTE_SLICE2_IRQ_GPIO_23},
+};
+
+static const struct tegra_hte_line_table aon_hte_map = {
+ .map_sz = ARRAY_SIZE(tegra194_aon_gpio_map),
+ .map = tegra194_aon_gpio_map,
+};
+
+static inline u32 tegra_hte_readl(struct tegra_hte_soc *hte, u32 reg)
+{
+ return readl(hte->regs + reg);
+}
+
+static inline void tegra_hte_writel(struct tegra_hte_soc *hte, u32 reg,
+ u32 val)
+{
+ writel(val, hte->regs + reg);
+}
+
+static inline int tegra_hte_map_to_line_id(u32 eid, struct tegra_hte_soc *gs,
+ u32 *mapped)
+{
+ const struct tegra_hte_line_mapped *m;
+
+ if (gs->line_map) {
+ m = gs->line_map->map;
+ if (eid > gs->line_map->map_sz)
+ return -EINVAL;
+ if (m[eid].slice == NV_AON_SLICE_INVALID)
+ return -EINVAL;
+
+ *mapped = (m[eid].slice << 5) + m[eid].bit_index;
+ } else {
+ *mapped = eid;
+ }
+
+ return 0;
+}
+
+static int tegra_hte_line_xlate(struct hte_chip *gc,
+ const struct of_phandle_args *args,
+ struct hte_ts_desc *desc, u32 *xlated_id)
+{
+ int ret = 0;
+
+ if (!gc || !desc || !xlated_id)
+ return -EINVAL;
+
+ if (args) {
+ if (gc->of_hte_n_cells < 1)
+ return -EINVAL;
+
+ if (args->args_count != gc->of_hte_n_cells)
+ return -EINVAL;
+
+ desc->con_id = args->args[0];
+ }
+
+ ret = tegra_hte_map_to_line_id(desc->con_id, gc->data,
+ xlated_id);
+ if (ret < 0) {
+ dev_dbg(gc->dev, "con_id:%u mapping failed\n",
+ desc->con_id);
+ return ret;
+ }
+
+ if (*xlated_id > gc->nlines)
+ return -EINVAL;
+
+ dev_dbg(gc->dev, "requested id:%u, xlated id:%u\n",
+ desc->con_id, *xlated_id);
+
+ return 0;
+}
+
+static int tegra_hte_en_dis_common(struct hte_chip *chip, u32 line_id, bool en)
+{
+ u32 slice, sl_bit_shift, line_bit, val, reg;
+ struct tegra_hte_soc *gs;
+
+ sl_bit_shift = __builtin_ctz(HTE_SLICE_SIZE);
+
+ if (!chip)
+ return -EINVAL;
+
+ gs = (struct tegra_hte_soc *)chip->data;
+
+ if (line_id > chip->nlines) {
+ dev_err(chip->dev,
+ "line id: %u is not supported by this controller\n",
+ line_id);
+ return -EINVAL;
+ }
+
+ slice = line_id >> sl_bit_shift;
+ line_bit = line_id & (HTE_SLICE_SIZE - 1);
+ reg = (slice << sl_bit_shift) + HTE_SLICE0_TETEN;
+
+ spin_lock(&gs->sl[slice].s_lock);
+
+ if (test_bit(HTE_SUSPEND, &gs->sl[slice].flags)) {
+ spin_unlock(&gs->sl[slice].s_lock);
+ dev_dbg(chip->dev, "device suspended");
+ return -EBUSY;
+ }
+
+ val = tegra_hte_readl(gs, reg);
+ if (en)
+ val = val | (1 << line_bit);
+ else
+ val = val & (~(1 << line_bit));
+ tegra_hte_writel(gs, reg, val);
+
+ spin_unlock(&gs->sl[slice].s_lock);
+
+ dev_dbg(chip->dev, "line: %u, slice %u, line_bit %u, reg:0x%x\n",
+ line_id, slice, line_bit, reg);
+
+ return 0;
+}
+
+static int tegra_hte_request(struct hte_chip *chip, u32 line_id)
+{
+ return tegra_hte_en_dis_common(chip, line_id, true);
+}
+
+static int tegra_hte_release(struct hte_chip *chip, u32 line_id)
+{
+ return tegra_hte_en_dis_common(chip, line_id, false);
+}
+
+static int tegra_hte_clk_src_info(struct hte_chip *chip,
+ struct hte_clk_info *ci)
+{
+ (void)chip;
+
+ if (!ci)
+ return -EINVAL;
+
+ ci->hz = HTE_TS_CLK_RATE_HZ;
+ ci->type = CLOCK_MONOTONIC;
+
+ return 0;
+}
+
+static void tegra_hte_read_fifo(struct tegra_hte_soc *gs)
+{
+ u32 tsh, tsl, src, pv, cv, acv, slice, bit_index, line_id;
+ u64 tsc;
+ struct hte_ts_data el;
+
+ while ((tegra_hte_readl(gs, HTE_TESTATUS) >>
+ HTE_TESTATUS_OCCUPANCY_SHIFT) &
+ HTE_TESTATUS_OCCUPANCY_MASK) {
+ tsh = tegra_hte_readl(gs, HTE_TETSCH);
+ tsl = tegra_hte_readl(gs, HTE_TETSCL);
+ tsc = (((u64)tsh << 32) | tsl);
+
+ src = tegra_hte_readl(gs, HTE_TESRC);
+ slice = (src >> HTE_TESRC_SLICE_SHIFT) &
+ HTE_TESRC_SLICE_DEFAULT_MASK;
+
+ pv = tegra_hte_readl(gs, HTE_TEPCV);
+ cv = tegra_hte_readl(gs, HTE_TECCV);
+ acv = pv ^ cv;
+ while (acv) {
+ bit_index = __builtin_ctz(acv);
+ el.dir = HTE_DIR_NOSUPP;
+ line_id = bit_index + (slice << 5);
+ el.tsc = tsc << HTE_TS_NS_SHIFT;
+ hte_push_ts_ns(gs->chip, line_id, &el);
+ acv &= ~BIT(bit_index);
+ }
+ tegra_hte_writel(gs, HTE_TECMD, HTE_TECMD_CMD_POP);
+ }
+}
+
+static irqreturn_t tegra_hte_isr(int irq, void *dev_id)
+{
+ struct tegra_hte_soc *gs = dev_id;
+ (void)irq;
+
+ tegra_hte_read_fifo(gs);
+
+ return IRQ_HANDLED;
+}
+
+static const struct of_device_id tegra_hte_of_match[] = {
+ { .compatible = "nvidia,tegra194-gte-lic"},
+ { .compatible = "nvidia,tegra194-gte-aon", .data = &aon_hte_map},
+ { }
+};
+MODULE_DEVICE_TABLE(of, tegra_hte_of_match);
+
+static const struct hte_ops g_ops = {
+ .request = tegra_hte_request,
+ .release = tegra_hte_release,
+ .enable = tegra_hte_request,
+ .disable = tegra_hte_release,
+ .get_clk_src_info = tegra_hte_clk_src_info,
+};
+
+static void tegra_gte_disable(void *data)
+{
+ struct platform_device *pdev = data;
+ struct tegra_hte_soc *gs = dev_get_drvdata(&pdev->dev);
+
+ tegra_hte_writel(gs, HTE_TECTRL, 0);
+}
+
+static int tegra_hte_probe(struct platform_device *pdev)
+{
+ int ret;
+ u32 i, slices, val = 0;
+ struct device *dev;
+ struct tegra_hte_soc *hte_dev;
+ struct hte_chip *gc;
+
+ dev = &pdev->dev;
+
+ hte_dev = devm_kzalloc(dev, sizeof(*hte_dev), GFP_KERNEL);
+ if (!hte_dev)
+ return -ENOMEM;
+
+ gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+ if (!gc)
+ return -ENOMEM;
+
+ dev_set_drvdata(&pdev->dev, hte_dev);
+ hte_dev->line_map = of_device_get_match_data(&pdev->dev);
+
+ hte_dev->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(hte_dev->regs))
+ return PTR_ERR(hte_dev->regs);
+
+ ret = of_property_read_u32(dev->of_node, "nvidia,int-threshold",
+ &hte_dev->itr_thrshld);
+ if (ret != 0)
+ hte_dev->itr_thrshld = 1;
+
+ ret = of_property_read_u32(dev->of_node, "nvidia,slices", &slices);
+ if (ret != 0) {
+ dev_err(dev, "Could not read slices\n");
+ return -EINVAL;
+ }
+
+ hte_dev->sl = devm_kcalloc(dev, slices, sizeof(*hte_dev->sl),
+ GFP_KERNEL);
+ if (!hte_dev->sl)
+ return -ENOMEM;
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret < 0) {
+ dev_err_probe(dev, ret, "failed to get irq\n");
+ return ret;
+ }
+ hte_dev->hte_irq = ret;
+ ret = devm_request_irq(dev, hte_dev->hte_irq, tegra_hte_isr, 0,
+ dev_name(dev), hte_dev);
+ if (ret < 0) {
+ dev_err(dev, "request irq failed.\n");
+ return ret;
+ }
+
+ gc->nlines = slices << 5;
+ gc->ops = &g_ops;
+ gc->dev = dev;
+ hte_dev->chip = gc;
+ gc->data = hte_dev;
+ gc->xlate = tegra_hte_line_xlate;
+ gc->of_hte_n_cells = 1;
+
+ ret = devm_hte_register_chip(hte_dev->chip);
+ if (ret) {
+ dev_err(gc->dev, "hte chip register failed");
+ return ret;
+ }
+
+ for (i = 0; i < slices; i++) {
+ hte_dev->sl[i].flags = 0;
+ spin_lock_init(&hte_dev->sl[i].s_lock);
+ }
+
+ val = HTE_TECTRL_ENABLE_ENABLE |
+ (HTE_TECTRL_INTR_ENABLE << HTE_TECTRL_INTR_SHIFT) |
+ (hte_dev->itr_thrshld << HTE_TECTRL_OCCU_SHIFT);
+ tegra_hte_writel(hte_dev, HTE_TECTRL, val);
+
+ ret = devm_add_action_or_reset(&pdev->dev, tegra_gte_disable, pdev);
+ if (ret)
+ return ret;
+
+ dev_dbg(gc->dev, "lines: %d, slices:%d", gc->nlines, slices);
+
+ return 0;
+}
+
+static int __maybe_unused tegra_hte_resume_early(struct device *dev)
+{
+ u32 i;
+ struct tegra_hte_soc *gs = dev_get_drvdata(dev);
+ u32 slices = gs->chip->nlines / NV_LINES_IN_SLICE;
+ u32 sl_bit_shift = __builtin_ctz(HTE_SLICE_SIZE);
+
+ tegra_hte_writel(gs, HTE_TECTRL, gs->conf_rval);
+
+ for (i = 0; i < slices; i++) {
+ spin_lock(&gs->sl[i].s_lock);
+ tegra_hte_writel(gs,
+ ((i << sl_bit_shift) + HTE_SLICE0_TETEN),
+ gs->sl[i].r_val);
+ clear_bit(HTE_SUSPEND, &gs->sl[i].flags);
+ spin_unlock(&gs->sl[i].s_lock);
+ }
+
+ return 0;
+}
+
+static int __maybe_unused tegra_hte_suspend_late(struct device *dev)
+{
+ u32 i;
+ struct tegra_hte_soc *gs = dev_get_drvdata(dev);
+ u32 slices = gs->chip->nlines / NV_LINES_IN_SLICE;
+ u32 sl_bit_shift = __builtin_ctz(HTE_SLICE_SIZE);
+
+ gs->conf_rval = tegra_hte_readl(gs, HTE_TECTRL);
+ for (i = 0; i < slices; i++) {
+ spin_lock(&gs->sl[i].s_lock);
+ gs->sl[i].r_val = tegra_hte_readl(gs,
+ ((i << sl_bit_shift) + HTE_SLICE0_TETEN));
+ set_bit(HTE_SUSPEND, &gs->sl[i].flags);
+ spin_unlock(&gs->sl[i].s_lock);
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops tegra_hte_pm = {
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(tegra_hte_suspend_late,
+ tegra_hte_resume_early)
+};
+
+static struct platform_driver tegra_hte_driver = {
+ .probe = tegra_hte_probe,
+ .driver = {
+ .name = "tegra_hte",
+ .pm = &tegra_hte_pm,
+ .of_match_table = tegra_hte_of_match,
+ },
+};
+
+module_platform_driver(tegra_hte_driver);
+
+MODULE_AUTHOR("Dipen Patel <dipenp@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra HTE (Hardware Timestamping Engine) driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1