[Patch net-next v3 01/13] net: dsa: microchip: ptp: add the posix clock support

Arun Ramadoss
2022-12-09T07:25:44Z

From: Christian Eggers <ceggers@arri.de>

This patch implement routines (adjfine, adjtime, gettime and settime)
for manipulating the chip's PTP clock. It registers the ptp caps
to posix clock register.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Co-developed-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>

---
v2 -> v3
- Reverted back to setting 802_1as bit.
- Also set the p2p bit which is required for the updating correction
field.

v1 -> v2
- added arri in copyright message
- Deleted setting 8021_1as bit and added P2P bit in ksz_ptp_clock_register()
- Renamed error_return label to unlock
- Assigned the ptp_clock_info directly instead of const struct
- moved the semicolon in ksz_rmw16 after 0x%x:
- moved ts_info to next patch

RFC v2 -> Patch v1
- Repharsed the Kconfig help text
- Removed IS_ERR_OR_NULL check in ptp_clock_unregister
- Add the check for ptp_data->clock in ksz_ptp_ts_info
- Renamed MAX_DRIFT_CORR to KSZ_MAX_DRIFT_CORR
- Removed the comments
- Variables declaration in reverse christmas tree
- Added the ptp_clock_optional
---
drivers/net/dsa/microchip/Kconfig | 11 ++
drivers/net/dsa/microchip/Makefile | 5 +
drivers/net/dsa/microchip/ksz_common.c | 13 +-
drivers/net/dsa/microchip/ksz_common.h | 16 ++
drivers/net/dsa/microchip/ksz_ptp.c | 240 ++++++++++++++++++++++++
drivers/net/dsa/microchip/ksz_ptp.h | 42 +++++
drivers/net/dsa/microchip/ksz_ptp_reg.h | 52 +++++
7 files changed, 378 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/dsa/microchip/ksz_ptp.c
create mode 100644 drivers/net/dsa/microchip/ksz_ptp.h
create mode 100644 drivers/net/dsa/microchip/ksz_ptp_reg.h

diff --git a/drivers/net/dsa/microchip/Kconfig b/drivers/net/dsa/microchip/Kconfig
index 913f83ef013c..0546c573668a 100644
--- a/drivers/net/dsa/microchip/Kconfig
+++ b/drivers/net/dsa/microchip/Kconfig
@@ -11,6 +11,7 @@ menuconfig NET_DSA_MICROCHIP_KSZ_COMMON
config NET_DSA_MICROCHIP_KSZ9477_I2C
tristate "KSZ series I2C connected switch driver"
depends on NET_DSA_MICROCHIP_KSZ_COMMON && I2C
+ depends on PTP_1588_CLOCK_OPTIONAL
select REGMAP_I2C
help
Select to enable support for registering switches configured through I2C.
@@ -18,10 +19,20 @@ config NET_DSA_MICROCHIP_KSZ9477_I2C
config NET_DSA_MICROCHIP_KSZ_SPI
tristate "KSZ series SPI connected switch driver"
depends on NET_DSA_MICROCHIP_KSZ_COMMON && SPI
+ depends on PTP_1588_CLOCK_OPTIONAL
select REGMAP_SPI
help
Select to enable support for registering switches configured through SPI.

+config NET_DSA_MICROCHIP_KSZ_PTP
+ bool "Support for the PTP clock on the KSZ9563/LAN937x Ethernet Switch"
+ depends on NET_DSA_MICROCHIP_KSZ_COMMON && PTP_1588_CLOCK
+ help
+ Select to enable support for timestamping & PTP clock manipulation in
+ KSZ8563/KSZ9563/LAN937x series of switches. KSZ9563/KSZ8563 supports
+ only one step timestamping. LAN937x switch supports both one step and
+ two step timestamping.
+
config NET_DSA_MICROCHIP_KSZ8863_SMI
tristate "KSZ series SMI connected switch driver"
depends on NET_DSA_MICROCHIP_KSZ_COMMON
diff --git a/drivers/net/dsa/microchip/Makefile b/drivers/net/dsa/microchip/Makefile
index 28873559efc2..48360cc9fc68 100644
--- a/drivers/net/dsa/microchip/Makefile
+++ b/drivers/net/dsa/microchip/Makefile
@@ -4,6 +4,11 @@ ksz_switch-objs := ksz_common.o
ksz_switch-objs += ksz9477.o
ksz_switch-objs += ksz8795.o
ksz_switch-objs += lan937x_main.o
+
+ifdef CONFIG_NET_DSA_MICROCHIP_KSZ_PTP
+ksz_switch-objs += ksz_ptp.o
+endif
+
obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ9477_I2C) += ksz9477_i2c.o
obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ_SPI) += ksz_spi.o
obj-$(CONFIG_NET_DSA_MICROCHIP_KSZ8863_SMI) += ksz8863_smi.o
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 423f944cc34c..a1282347fdc6 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -25,6 +25,7 @@
#include <net/switchdev.h>

#include "ksz_common.h"
+#include "ksz_ptp.h"
#include "ksz8.h"
#include "ksz9477.h"
#include "lan937x.h"
@@ -2103,10 +2104,16 @@ static int ksz_setup(struct dsa_switch *ds)
}
}

+ ret = ksz_ptp_clock_register(ds);
+ if (ret) {
+ dev_err(dev->dev, "Failed to register PTP clock: %d\n", ret);
+ goto out_pirq;
+ }
+
ret = ksz_mdio_register(dev);
if (ret < 0) {
dev_err(dev->dev, "failed to register the mdio");
- goto out_pirq;
+ goto out_ptp_clock_unregister;
}

/* start switch */
@@ -2115,6 +2122,8 @@ static int ksz_setup(struct dsa_switch *ds)

return 0;

+out_ptp_clock_unregister:
+ ksz_ptp_clock_unregister(ds);
out_pirq:
if (dev->irq > 0)
dsa_switch_for_each_user_port(dp, dev->ds)
@@ -2131,6 +2140,8 @@ static void ksz_teardown(struct dsa_switch *ds)
struct ksz_device *dev = ds->priv;
struct dsa_port *dp;

+ ksz_ptp_clock_unregister(ds);
+
if (dev->irq > 0) {
dsa_switch_for_each_user_port(dp, dev->ds)
ksz_irq_free(&dev->ports[dp->index].pirq);
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 055d61ff3fb8..23ed7fa72a3c 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -15,6 +15,8 @@
#include <net/dsa.h>
#include <linux/irq.h>

+#include "ksz_ptp.h"
+
#define KSZ_MAX_NUM_PORTS 8

struct ksz_device;
@@ -140,6 +142,7 @@ struct ksz_device {
u16 port_mask;
struct mutex lock_irq; /* IRQ Access */
struct ksz_irq girq;
+ struct ksz_ptp_data ptp_data;
};

/* List of supported models */
@@ -443,6 +446,19 @@ static inline int ksz_write32(struct ksz_device *dev, u32 reg, u32 value)
return ret;
}

+static inline int ksz_rmw16(struct ksz_device *dev, u32 reg, u16 mask,
+ u16 value)
+{
+ int ret;
+
+ ret = regmap_update_bits(dev->regmap[1], reg, mask, value);
+ if (ret)
+ dev_err(dev->dev, "can't rmw 16bit reg 0x%x: %pe\n", reg,
+ ERR_PTR(ret));
+
+ return ret;
+}
+
static inline int ksz_write64(struct ksz_device *dev, u32 reg, u64 value)
{
u32 val[2];
diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
new file mode 100644
index 000000000000..2da9b2ec0c40
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Microchip KSZ PTP Implementation
+ *
+ * Copyright (C) 2020 ARRI Lighting
+ * Copyright (C) 2022 Microchip Technology Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/ptp_classify.h>
+#include <linux/ptp_clock_kernel.h>
+
+#include "ksz_common.h"
+#include "ksz_ptp.h"
+#include "ksz_ptp_reg.h"
+
+#define ptp_caps_to_data(d) container_of((d), struct ksz_ptp_data, caps)
+#define ptp_data_to_ksz_dev(d) container_of((d), struct ksz_device, ptp_data)
+
+/* Sub-nanoseconds-adj,max * sub-nanoseconds / 40ns * 1ns
+ * = (2^30-1) * (2 ^ 32) / 40 ns * 1 ns = 6249999
+ */
+#define KSZ_MAX_DRIFT_CORR 6249999
+
+#define KSZ_PTP_INC_NS 40 /* HW clock is incremented every 40 ns (by 40) */
+#define KSZ_PTP_SUBNS_BITS 32
+
+static int _ksz_ptp_gettime(struct ksz_device *dev, struct timespec64 *ts)
+{
+ u32 nanoseconds;
+ u32 seconds;
+ u8 phase;
+ int ret;
+
+ /* Copy current PTP clock into shadow registers and read */
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_READ_TIME, PTP_READ_TIME);
+ if (ret)
+ return ret;
+
+ ret = ksz_read8(dev, REG_PTP_RTC_SUB_NANOSEC__2, &phase);
+ if (ret)
+ return ret;
+
+ ret = ksz_read32(dev, REG_PTP_RTC_NANOSEC, &nanoseconds);
+ if (ret)
+ return ret;
+
+ ret = ksz_read32(dev, REG_PTP_RTC_SEC, &seconds);
+ if (ret)
+ return ret;
+
+ ts->tv_sec = seconds;
+ ts->tv_nsec = nanoseconds + phase * 8;
+
+ return 0;
+}
+
+static int ksz_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+ ret = _ksz_ptp_gettime(dev, ts);
+ mutex_unlock(&ptp_data->lock);
+
+ return ret;
+}
+
+static int ksz_ptp_settime(struct ptp_clock_info *ptp,
+ const struct timespec64 *ts)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ /* Write to shadow registers and Load PTP clock */
+ ret = ksz_write16(dev, REG_PTP_RTC_SUB_NANOSEC__2, PTP_RTC_0NS);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_write32(dev, REG_PTP_RTC_NANOSEC, ts->tv_nsec);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_write32(dev, REG_PTP_RTC_SEC, ts->tv_sec);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_LOAD_TIME, PTP_LOAD_TIME);
+
+unlock:
+ mutex_unlock(&ptp_data->lock);
+
+ return ret;
+}
+
+static int ksz_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ if (scaled_ppm) {
+ s64 ppb, adj;
+ u32 data32;
+
+ /* see scaled_ppm_to_ppb() in ptp_clock.c for details */
+ ppb = 1 + scaled_ppm;
+ ppb *= 125;
+ ppb *= KSZ_PTP_INC_NS;
+ ppb <<= KSZ_PTP_SUBNS_BITS - 13;
+ adj = div_s64(ppb, NSEC_PER_SEC);
+
+ data32 = abs(adj);
+ data32 &= PTP_SUBNANOSEC_M;
+ if (adj >= 0)
+ data32 |= PTP_RATE_DIR;
+
+ ret = ksz_write32(dev, REG_PTP_SUBNANOSEC_RATE, data32);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ADJ_ENABLE,
+ PTP_CLK_ADJ_ENABLE);
+ if (ret)
+ goto unlock;
+ } else {
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ADJ_ENABLE, 0);
+ if (ret)
+ goto unlock;
+ }
+
+unlock:
+ mutex_unlock(&ptp_data->lock);
+ return ret;
+}
+
+static int ksz_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ s32 sec, nsec;
+ u16 data16;
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ /* do not use ns_to_timespec64(),
+ * both sec and nsec are subtracted by hw
+ */
+ sec = div_s64_rem(delta, NSEC_PER_SEC, &nsec);
+
+ ret = ksz_write32(dev, REG_PTP_RTC_NANOSEC, abs(nsec));
+ if (ret)
+ goto unlock;
+
+ ret = ksz_write32(dev, REG_PTP_RTC_SEC, abs(sec));
+ if (ret)
+ goto unlock;
+
+ ret = ksz_read16(dev, REG_PTP_CLK_CTRL, &data16);
+ if (ret)
+ goto unlock;
+
+ data16 |= PTP_STEP_ADJ;
+
+ /* PTP_STEP_DIR -- 0: subtract, 1: add */
+ if (delta < 0)
+ data16 &= ~PTP_STEP_DIR;
+ else
+ data16 |= PTP_STEP_DIR;
+
+ ret = ksz_write16(dev, REG_PTP_CLK_CTRL, data16);
+
+unlock:
+ mutex_unlock(&ptp_data->lock);
+ return ret;
+}
+
+static int ksz_ptp_start_clock(struct ksz_device *dev)
+{
+ return ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ENABLE, PTP_CLK_ENABLE);
+}
+
+int ksz_ptp_clock_register(struct dsa_switch *ds)
+{
+ struct ksz_device *dev = ds->priv;
+ struct ksz_ptp_data *ptp_data;
+ int ret;
+
+ ptp_data = &dev->ptp_data;
+ mutex_init(&ptp_data->lock);
+
+ ptp_data->caps.owner = THIS_MODULE;
+ snprintf(ptp_data->caps.name, 16, "Microchip Clock");
+ ptp_data->caps.max_adj = KSZ_MAX_DRIFT_CORR;
+ ptp_data->caps.gettime64 = ksz_ptp_gettime;
+ ptp_data->caps.settime64 = ksz_ptp_settime;
+ ptp_data->caps.adjfine = ksz_ptp_adjfine;
+ ptp_data->caps.adjtime = ksz_ptp_adjtime;
+
+ ret = ksz_ptp_start_clock(dev);
+ if (ret)
+ return ret;
+
+ /* Currently only P2P mode is supported. When 802_1AS bit is set, it
+ * forwards all PTP packets to host port and none to other ports.
+ */
+ ret = ksz_rmw16(dev, REG_PTP_MSG_CONF1, PTP_TC_P2P | PTP_802_1AS,
+ PTP_TC_P2P | PTP_802_1AS);
+ if (ret)
+ return ret;
+
+ ptp_data->clock = ptp_clock_register(&ptp_data->caps, dev->dev);
+ if (IS_ERR_OR_NULL(ptp_data->clock))
+ return PTR_ERR(ptp_data->clock);
+
+ return 0;
+}
+
+void ksz_ptp_clock_unregister(struct dsa_switch *ds)
+{
+ struct ksz_device *dev = ds->priv;
+ struct ksz_ptp_data *ptp_data;
+
+ ptp_data = &dev->ptp_data;
+
+ if (ptp_data->clock)
+ ptp_clock_unregister(ptp_data->clock);
+}
+
+MODULE_AUTHOR("Christian Eggers <ceggers@arri.de>");
+MODULE_AUTHOR("Arun Ramadoss <arun.ramadoss@microchip.com>");
+MODULE_DESCRIPTION("PTP support for KSZ switch");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/dsa/microchip/ksz_ptp.h b/drivers/net/dsa/microchip/ksz_ptp.h
new file mode 100644
index 000000000000..8930047da764
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz_ptp.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip KSZ PTP Implementation
+ *
+ * Copyright (C) 2020 ARRI Lighting
+ * Copyright (C) 2022 Microchip Technology Inc.
+ */
+
+#ifndef _NET_DSA_DRIVERS_KSZ_PTP_H
+#define _NET_DSA_DRIVERS_KSZ_PTP_H
+
+#if IS_ENABLED(CONFIG_NET_DSA_MICROCHIP_KSZ_PTP)
+
+#include <linux/ptp_clock_kernel.h>
+
+struct ksz_ptp_data {
+ struct ptp_clock_info caps;
+ struct ptp_clock *clock;
+ /* Serializes all operations on the PTP hardware clock */
+ struct mutex lock;
+};
+
+int ksz_ptp_clock_register(struct dsa_switch *ds);
+
+void ksz_ptp_clock_unregister(struct dsa_switch *ds);
+
+#else
+
+struct ksz_ptp_data {
+ /* Serializes all operations on the PTP hardware clock */
+ struct mutex lock;
+};
+
+static inline int ksz_ptp_clock_register(struct dsa_switch *ds)
+{
+ return 0;
+}
+
+static inline void ksz_ptp_clock_unregister(struct dsa_switch *ds) { }
+
+#endif /* End of CONFIG_NET_DSA_MICROCHIP_KSZ_PTP */
+
+#endif
diff --git a/drivers/net/dsa/microchip/ksz_ptp_reg.h b/drivers/net/dsa/microchip/ksz_ptp_reg.h
new file mode 100644
index 000000000000..4ca4ad4bba7e
--- /dev/null
+++ b/drivers/net/dsa/microchip/ksz_ptp_reg.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip KSZ PTP register definitions
+ * Copyright (C) 2022 Microchip Technology Inc.
+ */
+
+#ifndef __KSZ_PTP_REGS_H
+#define __KSZ_PTP_REGS_H
+
+/* 5 - PTP Clock */
+#define REG_PTP_CLK_CTRL 0x0500
+
+#define PTP_STEP_ADJ BIT(6)
+#define PTP_STEP_DIR BIT(5)
+#define PTP_READ_TIME BIT(4)
+#define PTP_LOAD_TIME BIT(3)
+#define PTP_CLK_ADJ_ENABLE BIT(2)
+#define PTP_CLK_ENABLE BIT(1)
+#define PTP_CLK_RESET BIT(0)
+
+#define REG_PTP_RTC_SUB_NANOSEC__2 0x0502
+
+#define PTP_RTC_SUB_NANOSEC_M 0x0007
+#define PTP_RTC_0NS 0x00
+
+#define REG_PTP_RTC_NANOSEC 0x0504
+
+#define REG_PTP_RTC_SEC 0x0508
+
+#define REG_PTP_SUBNANOSEC_RATE 0x050C
+
+#define PTP_SUBNANOSEC_M 0x3FFFFFFF
+#define PTP_RATE_DIR BIT(31)
+#define PTP_TMP_RATE_ENABLE BIT(30)
+
+#define REG_PTP_SUBNANOSEC_RATE_L 0x050E
+
+#define REG_PTP_RATE_DURATION 0x0510
+#define REG_PTP_RATE_DURATION_H 0x0510
+#define REG_PTP_RATE_DURATION_L 0x0512
+
+#define REG_PTP_MSG_CONF1 0x0514
+
+#define PTP_802_1AS BIT(7)
+#define PTP_ENABLE BIT(6)
+#define PTP_ETH_ENABLE BIT(5)
+#define PTP_IPV4_UDP_ENABLE BIT(4)
+#define PTP_IPV6_UDP_ENABLE BIT(3)
+#define PTP_TC_P2P BIT(2)
+#define PTP_MASTER BIT(1)
+#define PTP_1STEP BIT(0)
+
+#endif
--
2.36.1