net: ti: icss-iep: Add IEP driver

Add a driver for Industrial Ethernet Peripheral (IEP) block of PRUSS to
support timestamping of ethernet packets and thus support PTP and PPS
for PRU ethernet ports.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/Kconfig

@@ -196,4 +196,15 @@ config TI_ICSSG_PRUETH
 	  to support the Ethernet operation. Currently, it supports Ethernet
 	  with 1G and 100M link speed.
 
+config TI_ICSS_IEP
+	tristate "TI PRU ICSS IEP driver"
+	depends on TI_PRUSS
+	default TI_PRUSS
+	help
+	  This driver enables support for the PRU-ICSS Industrial Ethernet
+	  Peripheral within a PRU-ICSS subsystem present on various TI SoCs.
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called icss_iep.
+
 endif # NET_VENDOR_TI

drivers/net/ethernet/ti/Makefile

@@ -38,3 +38,4 @@ icssg-prueth-y := k3-cppi-desc-pool.o \
 		  icssg/icssg_mii_cfg.o \
 		  icssg/icssg_stats.o \
 		  icssg/icssg_ethtool.o
+obj-$(CONFIG_TI_ICSS_IEP) += icssg/icss_iep.o

drivers/net/ethernet/ti/icssg/icss_iep.c

+// SPDX-License-Identifier: GPL-2.0
+
+/* Texas Instruments ICSSG Industrial Ethernet Peripheral (IEP) Driver
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/timekeeping.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+
+#include "icss_iep.h"
+
+#define IEP_MAX_DEF_INC		0xf
+#define IEP_MAX_COMPEN_INC		0xfff
+#define IEP_MAX_COMPEN_COUNT	0xffffff
+
+#define IEP_GLOBAL_CFG_CNT_ENABLE	BIT(0)
+#define IEP_GLOBAL_CFG_DEFAULT_INC_MASK		GENMASK(7, 4)
+#define IEP_GLOBAL_CFG_DEFAULT_INC_SHIFT	4
+#define IEP_GLOBAL_CFG_COMPEN_INC_MASK		GENMASK(19, 8)
+#define IEP_GLOBAL_CFG_COMPEN_INC_SHIFT		8
+
+#define IEP_GLOBAL_STATUS_CNT_OVF	BIT(0)
+
+#define IEP_CMP_CFG_SHADOW_EN		BIT(17)
+#define IEP_CMP_CFG_CMP0_RST_CNT_EN	BIT(0)
+#define IEP_CMP_CFG_CMP_EN(cmp)		(GENMASK(16, 1) & (1 << ((cmp) + 1)))
+
+#define IEP_CMP_STATUS(cmp)		(1 << (cmp))
+
+#define IEP_SYNC_CTRL_SYNC_EN		BIT(0)
+#define IEP_SYNC_CTRL_SYNC_N_EN(n)	(GENMASK(2, 1) & (BIT(1) << (n)))
+
+#define IEP_MIN_CMP	0
+#define IEP_MAX_CMP	15
+
+#define ICSS_IEP_64BIT_COUNTER_SUPPORT		BIT(0)
+#define ICSS_IEP_SLOW_COMPEN_REG_SUPPORT	BIT(1)
+#define ICSS_IEP_SHADOW_MODE_SUPPORT		BIT(2)
+
+#define LATCH_INDEX(ts_index)			((ts_index) + 6)
+#define IEP_CAP_CFG_CAPNR_1ST_EVENT_EN(n)	BIT(LATCH_INDEX(n))
+#define IEP_CAP_CFG_CAP_ASYNC_EN(n)		BIT(LATCH_INDEX(n) + 10)
+
+enum {
+	ICSS_IEP_GLOBAL_CFG_REG,
+	ICSS_IEP_GLOBAL_STATUS_REG,
+	ICSS_IEP_COMPEN_REG,
+	ICSS_IEP_SLOW_COMPEN_REG,
+	ICSS_IEP_COUNT_REG0,
+	ICSS_IEP_COUNT_REG1,
+	ICSS_IEP_CAPTURE_CFG_REG,
+	ICSS_IEP_CAPTURE_STAT_REG,
+
+	ICSS_IEP_CAP6_RISE_REG0,
+	ICSS_IEP_CAP6_RISE_REG1,
+
+	ICSS_IEP_CAP7_RISE_REG0,
+	ICSS_IEP_CAP7_RISE_REG1,
+
+	ICSS_IEP_CMP_CFG_REG,
+	ICSS_IEP_CMP_STAT_REG,
+	ICSS_IEP_CMP0_REG0,
+	ICSS_IEP_CMP0_REG1,
+	ICSS_IEP_CMP1_REG0,
+	ICSS_IEP_CMP1_REG1,
+
+	ICSS_IEP_CMP8_REG0,
+	ICSS_IEP_CMP8_REG1,
+	ICSS_IEP_SYNC_CTRL_REG,
+	ICSS_IEP_SYNC0_STAT_REG,
+	ICSS_IEP_SYNC1_STAT_REG,
+	ICSS_IEP_SYNC_PWIDTH_REG,
+	ICSS_IEP_SYNC0_PERIOD_REG,
+	ICSS_IEP_SYNC1_DELAY_REG,
+	ICSS_IEP_SYNC_START_REG,
+	ICSS_IEP_MAX_REGS,
+};
+
+/**
+ * struct icss_iep_plat_data - Plat data to handle SoC variants
+ * @config: Regmap configuration data
+ * @reg_offs: register offsets to capture offset differences across SoCs
+ * @flags: Flags to represent IEP properties
+ */
+struct icss_iep_plat_data {
+	struct regmap_config *config;
+	u32 reg_offs[ICSS_IEP_MAX_REGS];
+	u32 flags;
+};
+
+struct icss_iep {
+	struct device *dev;
+	void __iomem *base;
+	const struct icss_iep_plat_data *plat_data;
+	struct regmap *map;
+	struct device_node *client_np;
+	unsigned long refclk_freq;
+	int clk_tick_time;	/* one refclk tick time in ns */
+	struct ptp_clock_info ptp_info;
+	struct ptp_clock *ptp_clock;
+	struct mutex ptp_clk_mutex;	/* PHC access serializer */
+	spinlock_t irq_lock; /* CMP IRQ vs icss_iep_ptp_enable access */
+	u32 def_inc;
+	s16 slow_cmp_inc;
+	u32 slow_cmp_count;
+	const struct icss_iep_clockops *ops;
+	void *clockops_data;
+	u32 cycle_time_ns;
+	u32 perout_enabled;
+	bool pps_enabled;
+	int cap_cmp_irq;
+	u64 period;
+	u32 latch_enable;
+};
+
+/**
+ * icss_iep_get_count_hi() - Get the upper 32 bit IEP counter
+ * @iep: Pointer to structure representing IEP.
+ *
+ * Return: upper 32 bit IEP counter
+ */
+int icss_iep_get_count_hi(struct icss_iep *iep)
+{
+	u32 val = 0;
+
+	if (iep && (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT))
+		val = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG1]);
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(icss_iep_get_count_hi);
+
+/**
+ * icss_iep_get_count_low() - Get the lower 32 bit IEP counter
+ * @iep: Pointer to structure representing IEP.
+ *
+ * Return: lower 32 bit IEP counter
+ */
+int icss_iep_get_count_low(struct icss_iep *iep)
+{
+	u32 val = 0;
+
+	if (iep)
+		val = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG0]);
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(icss_iep_get_count_low);
+
+/**
+ * icss_iep_get_ptp_clock_idx() - Get PTP clock index using IEP driver
+ * @iep: Pointer to structure representing IEP.
+ *
+ * Return: PTP clock index, -1 if not registered
+ */
+int icss_iep_get_ptp_clock_idx(struct icss_iep *iep)
+{
+	if (!iep || !iep->ptp_clock)
+		return -1;
+	return ptp_clock_index(iep->ptp_clock);
+}
+EXPORT_SYMBOL_GPL(icss_iep_get_ptp_clock_idx);
+
+static void icss_iep_set_counter(struct icss_iep *iep, u64 ns)
+{
+	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+		writel(upper_32_bits(ns), iep->base +
+		       iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG1]);
+	writel(upper_32_bits(ns), iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG0]);
+}
+
+static void icss_iep_update_to_next_boundary(struct icss_iep *iep, u64 start_ns);
+
+/**
+ * icss_iep_settime() - Set time of the PTP clock using IEP driver
+ * @iep: Pointer to structure representing IEP.
+ * @ns: Time to be set in nanoseconds
+ *
+ * This API uses writel() instead of regmap_write() for write operations as
+ * regmap_write() is too slow and this API is time sensitive.
+ */
+static void icss_iep_settime(struct icss_iep *iep, u64 ns)
+{
+	unsigned long flags;
+
+	if (iep->ops && iep->ops->settime) {
+		iep->ops->settime(iep->clockops_data, ns);
+		return;
+	}
+
+	spin_lock_irqsave(&iep->irq_lock, flags);
+	if (iep->pps_enabled || iep->perout_enabled)
+		writel(0, iep->base + iep->plat_data->reg_offs[ICSS_IEP_SYNC_CTRL_REG]);
+
+	icss_iep_set_counter(iep, ns);
+
+	if (iep->pps_enabled || iep->perout_enabled) {
+		icss_iep_update_to_next_boundary(iep, ns);
+		writel(IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN,
+		       iep->base + iep->plat_data->reg_offs[ICSS_IEP_SYNC_CTRL_REG]);
+	}
+	spin_unlock_irqrestore(&iep->irq_lock, flags);
+}
+
+/**
+ * icss_iep_gettime() - Get time of the PTP clock using IEP driver
+ * @iep: Pointer to structure representing IEP.
+ * @sts: Pointer to structure representing PTP system timestamp.
+ *
+ * This API uses readl() instead of regmap_read() for read operations as
+ * regmap_read() is too slow and this API is time sensitive.
+ *
+ * Return: The current timestamp of the PTP clock using IEP driver
+ */
+static u64 icss_iep_gettime(struct icss_iep *iep,
+			    struct ptp_system_timestamp *sts)
+{
+	u32 ts_hi = 0, ts_lo;
+	unsigned long flags;
+
+	if (iep->ops && iep->ops->gettime)
+		return iep->ops->gettime(iep->clockops_data, sts);
+
+	/* use local_irq_x() to make it work for both RT/non-RT */
+	local_irq_save(flags);
+
+	/* no need to play with hi-lo, hi is latched when lo is read */
+	ptp_read_system_prets(sts);
+	ts_lo = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG0]);
+	ptp_read_system_postts(sts);
+	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+		ts_hi = readl(iep->base + iep->plat_data->reg_offs[ICSS_IEP_COUNT_REG1]);
+
+	local_irq_restore(flags);
+
+	return (u64)ts_lo | (u64)ts_hi << 32;
+}
+
+static void icss_iep_enable(struct icss_iep *iep)
+{
+	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
+			   IEP_GLOBAL_CFG_CNT_ENABLE,
+			   IEP_GLOBAL_CFG_CNT_ENABLE);
+}
+
+static void icss_iep_disable(struct icss_iep *iep)
+{
+	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
+			   IEP_GLOBAL_CFG_CNT_ENABLE,
+			   0);
+}
+
+static void icss_iep_enable_shadow_mode(struct icss_iep *iep)
+{
+	u32 cycle_time;
+	int cmp;
+
+	cycle_time = iep->cycle_time_ns - iep->def_inc;
+
+	icss_iep_disable(iep);
+
+	/* disable shadow mode */
+	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+			   IEP_CMP_CFG_SHADOW_EN, 0);
+
+	/* enable shadow mode */
+	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+			   IEP_CMP_CFG_SHADOW_EN, IEP_CMP_CFG_SHADOW_EN);
+
+	/* clear counters */
+	icss_iep_set_counter(iep, 0);
+
+	/* clear overflow status */
+	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_STATUS_REG,
+			   IEP_GLOBAL_STATUS_CNT_OVF,
+			   IEP_GLOBAL_STATUS_CNT_OVF);
+
+	/* clear compare status */
+	for (cmp = IEP_MIN_CMP; cmp < IEP_MAX_CMP; cmp++) {
+		regmap_update_bits(iep->map, ICSS_IEP_CMP_STAT_REG,
+				   IEP_CMP_STATUS(cmp), IEP_CMP_STATUS(cmp));
+	}
+
+	/* enable reset counter on CMP0 event */
+	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+			   IEP_CMP_CFG_CMP0_RST_CNT_EN,
+			   IEP_CMP_CFG_CMP0_RST_CNT_EN);
+	/* enable compare */
+	regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+			   IEP_CMP_CFG_CMP_EN(0),
+			   IEP_CMP_CFG_CMP_EN(0));
+
+	/* set CMP0 value to cycle time */
+	regmap_write(iep->map, ICSS_IEP_CMP0_REG0, cycle_time);
+	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+		regmap_write(iep->map, ICSS_IEP_CMP0_REG1, cycle_time);
+
+	icss_iep_set_counter(iep, 0);
+	icss_iep_enable(iep);
+}
+
+static void icss_iep_set_default_inc(struct icss_iep *iep, u8 def_inc)
+{
+	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
+			   IEP_GLOBAL_CFG_DEFAULT_INC_MASK,
+			   def_inc << IEP_GLOBAL_CFG_DEFAULT_INC_SHIFT);
+}
+
+static void icss_iep_set_compensation_inc(struct icss_iep *iep, u16 compen_inc)
+{
+	struct device *dev = regmap_get_device(iep->map);
+
+	if (compen_inc > IEP_MAX_COMPEN_INC) {
+		dev_err(dev, "%s: too high compensation inc %d\n",
+			__func__, compen_inc);
+		compen_inc = IEP_MAX_COMPEN_INC;
+	}
+
+	regmap_update_bits(iep->map, ICSS_IEP_GLOBAL_CFG_REG,
+			   IEP_GLOBAL_CFG_COMPEN_INC_MASK,
+			   compen_inc << IEP_GLOBAL_CFG_COMPEN_INC_SHIFT);
+}
+
+static void icss_iep_set_compensation_count(struct icss_iep *iep,
+					    u32 compen_count)
+{
+	struct device *dev = regmap_get_device(iep->map);
+
+	if (compen_count > IEP_MAX_COMPEN_COUNT) {
+		dev_err(dev, "%s: too high compensation count %d\n",
+			__func__, compen_count);
+		compen_count = IEP_MAX_COMPEN_COUNT;
+	}
+
+	regmap_write(iep->map, ICSS_IEP_COMPEN_REG, compen_count);
+}
+
+static void icss_iep_set_slow_compensation_count(struct icss_iep *iep,
+						 u32 compen_count)
+{
+	regmap_write(iep->map, ICSS_IEP_SLOW_COMPEN_REG, compen_count);
+}
+
+/* PTP PHC operations */
+static int icss_iep_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
+	s32 ppb = scaled_ppm_to_ppb(scaled_ppm);
+	u32 cyc_count;
+	u16 cmp_inc;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+
+	/* ppb is amount of frequency we want to adjust in 1GHz (billion)
+	 * e.g. 100ppb means we need to speed up clock by 100Hz
+	 * i.e. at end of 1 second (1 billion ns) clock time, we should be
+	 * counting 100 more ns.
+	 * We use IEP slow compensation to achieve continuous freq. adjustment.
+	 * There are 2 parts. Cycle time and adjustment per cycle.
+	 * Simplest case would be 1 sec Cycle time. Then adjustment
+	 * pre cycle would be (def_inc + ppb) value.
+	 * Cycle time will have to be chosen based on how worse the ppb is.
+	 * e.g. smaller the ppb, cycle time has to be large.
+	 * The minimum adjustment we can do is +-1ns per cycle so let's
+	 * reduce the cycle time to get 1ns per cycle adjustment.
+	 *	1ppb = 1sec cycle time & 1ns adjust
+	 *	1000ppb = 1/1000 cycle time & 1ns adjust per cycle
+	 */
+
+	if (iep->cycle_time_ns)
+		iep->slow_cmp_inc = iep->clk_tick_time;	/* 4ns adj per cycle */
+	else
+		iep->slow_cmp_inc = 1;	/* 1ns adjust per cycle */
+
+	if (ppb < 0) {
+		iep->slow_cmp_inc = -iep->slow_cmp_inc;
+		ppb = -ppb;
+	}
+
+	cyc_count = NSEC_PER_SEC;		/* 1s cycle time @1GHz */
+	cyc_count /= ppb;		/* cycle time per ppb */
+
+	/* slow_cmp_count is decremented every clock cycle, e.g. @250MHz */
+	if (!iep->cycle_time_ns)
+		cyc_count /= iep->clk_tick_time;
+	iep->slow_cmp_count = cyc_count;
+
+	/* iep->clk_tick_time is def_inc */
+	cmp_inc = iep->clk_tick_time + iep->slow_cmp_inc;
+	icss_iep_set_compensation_inc(iep, cmp_inc);
+	icss_iep_set_slow_compensation_count(iep, iep->slow_cmp_count);
+
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return 0;
+}
+
+static int icss_iep_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
+	s64 ns;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+	if (iep->ops && iep->ops->adjtime) {
+		iep->ops->adjtime(iep->clockops_data, delta);
+	} else {
+		ns = icss_iep_gettime(iep, NULL);
+		ns += delta;
+		icss_iep_settime(iep, ns);
+	}
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return 0;
+}
+
+static int icss_iep_ptp_gettimeex(struct ptp_clock_info *ptp,
+				  struct timespec64 *ts,
+				  struct ptp_system_timestamp *sts)
+{
+	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
+	u64 ns;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+	ns = icss_iep_gettime(iep, sts);
+	*ts = ns_to_timespec64(ns);
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return 0;
+}
+
+static int icss_iep_ptp_settime(struct ptp_clock_info *ptp,
+				const struct timespec64 *ts)
+{
+	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
+	u64 ns;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+	ns = timespec64_to_ns(ts);
+	icss_iep_settime(iep, ns);
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return 0;
+}
+
+static void icss_iep_update_to_next_boundary(struct icss_iep *iep, u64 start_ns)
+{
+	u64 ns, p_ns;
+	u32 offset;
+
+	ns = icss_iep_gettime(iep, NULL);
+	if (start_ns < ns)
+		start_ns = ns;
+	p_ns = iep->period;
+	/* Round up to next period boundary */
+	start_ns += p_ns - 1;
+	offset = do_div(start_ns, p_ns);
+	start_ns = start_ns * p_ns;
+	/* If it is too close to update, shift to next boundary */
+	if (p_ns - offset < 10)
+		start_ns += p_ns;
+
+	regmap_write(iep->map, ICSS_IEP_CMP1_REG0, lower_32_bits(start_ns));
+	if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+		regmap_write(iep->map, ICSS_IEP_CMP1_REG1, upper_32_bits(start_ns));
+}
+
+static int icss_iep_perout_enable_hw(struct icss_iep *iep,
+				     struct ptp_perout_request *req, int on)
+{
+	int ret;
+	u64 cmp;
+
+	if (iep->ops && iep->ops->perout_enable) {
+		ret = iep->ops->perout_enable(iep->clockops_data, req, on, &cmp);
+		if (ret)
+			return ret;
+
+		if (on) {
+			/* Configure CMP */
+			regmap_write(iep->map, ICSS_IEP_CMP1_REG0, lower_32_bits(cmp));
+			if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+				regmap_write(iep->map, ICSS_IEP_CMP1_REG1, upper_32_bits(cmp));
+			/* Configure SYNC, 1ms pulse width */
+			regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG, 1000000);
+			regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
+			regmap_write(iep->map, ICSS_IEP_SYNC_START_REG, 0);
+			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0); /* one-shot mode */
+			/* Enable CMP 1 */
+			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+					   IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
+		} else {
+			/* Disable CMP 1 */
+			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+					   IEP_CMP_CFG_CMP_EN(1), 0);
+
+			/* clear regs */
+			regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
+			if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+				regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
+		}
+	} else {
+		if (on) {
+			u64 start_ns;
+
+			iep->period = ((u64)req->period.sec * NSEC_PER_SEC) +
+				      req->period.nsec;
+			start_ns = ((u64)req->period.sec * NSEC_PER_SEC)
+				   + req->period.nsec;
+			icss_iep_update_to_next_boundary(iep, start_ns);
+
+			/* Enable Sync in single shot mode  */
+			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG,
+				     IEP_SYNC_CTRL_SYNC_N_EN(0) | IEP_SYNC_CTRL_SYNC_EN);
+			/* Enable CMP 1 */
+			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+					   IEP_CMP_CFG_CMP_EN(1), IEP_CMP_CFG_CMP_EN(1));
+		} else {
+			/* Disable CMP 1 */
+			regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+					   IEP_CMP_CFG_CMP_EN(1), 0);
+
+			/* clear CMP regs */
+			regmap_write(iep->map, ICSS_IEP_CMP1_REG0, 0);
+			if (iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT)
+				regmap_write(iep->map, ICSS_IEP_CMP1_REG1, 0);
+
+			/* Disable sync */
+			regmap_write(iep->map, ICSS_IEP_SYNC_CTRL_REG, 0);
+		}
+	}
+
+	return 0;
+}
+
+static int icss_iep_perout_enable(struct icss_iep *iep,
+				  struct ptp_perout_request *req, int on)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+
+	if (iep->pps_enabled) {
+		ret = -EBUSY;
+		goto exit;
+	}
+
+	if (iep->perout_enabled == !!on)
+		goto exit;
+
+	spin_lock_irqsave(&iep->irq_lock, flags);
+	ret = icss_iep_perout_enable_hw(iep, req, on);
+	if (!ret)
+		iep->perout_enabled = !!on;
+	spin_unlock_irqrestore(&iep->irq_lock, flags);
+
+exit:
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return ret;
+}
+
+static int icss_iep_pps_enable(struct icss_iep *iep, int on)
+{
+	struct ptp_clock_request rq;
+	struct timespec64 ts;
+	unsigned long flags;
+	int ret = 0;
+	u64 ns;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+
+	if (iep->perout_enabled) {
+		ret = -EBUSY;
+		goto exit;
+	}
+
+	if (iep->pps_enabled == !!on)
+		goto exit;
+
+	spin_lock_irqsave(&iep->irq_lock, flags);
+
+	rq.perout.index = 0;
+	if (on) {
+		ns = icss_iep_gettime(iep, NULL);
+		ts = ns_to_timespec64(ns);
+		rq.perout.period.sec = 1;
+		rq.perout.period.nsec = 0;
+		rq.perout.start.sec = ts.tv_sec + 2;
+		rq.perout.start.nsec = 0;
+		ret = icss_iep_perout_enable_hw(iep, &rq.perout, on);
+	} else {
+		ret = icss_iep_perout_enable_hw(iep, &rq.perout, on);
+	}
+
+	if (!ret)
+		iep->pps_enabled = !!on;
+
+	spin_unlock_irqrestore(&iep->irq_lock, flags);
+
+exit:
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return ret;
+}
+
+static int icss_iep_extts_enable(struct icss_iep *iep, u32 index, int on)
+{
+	u32 val, cap, ret = 0;
+
+	mutex_lock(&iep->ptp_clk_mutex);
+
+	if (iep->ops && iep->ops->extts_enable) {
+		ret = iep->ops->extts_enable(iep->clockops_data, index, on);
+		goto exit;
+	}
+
+	if (((iep->latch_enable & BIT(index)) >> index) == on)
+		goto exit;
+
+	regmap_read(iep->map, ICSS_IEP_CAPTURE_CFG_REG, &val);
+	cap = IEP_CAP_CFG_CAP_ASYNC_EN(index) | IEP_CAP_CFG_CAPNR_1ST_EVENT_EN(index);
+	if (on) {
+		val |= cap;
+		iep->latch_enable |= BIT(index);
+	} else {
+		val &= ~cap;
+		iep->latch_enable &= ~BIT(index);
+	}
+	regmap_write(iep->map, ICSS_IEP_CAPTURE_CFG_REG, val);
+
+exit:
+	mutex_unlock(&iep->ptp_clk_mutex);
+
+	return ret;
+}
+
+static int icss_iep_ptp_enable(struct ptp_clock_info *ptp,
+			       struct ptp_clock_request *rq, int on)
+{
+	struct icss_iep *iep = container_of(ptp, struct icss_iep, ptp_info);
+
+	switch (rq->type) {
+	case PTP_CLK_REQ_PEROUT:
+		return icss_iep_perout_enable(iep, &rq->perout, on);
+	case PTP_CLK_REQ_PPS:
+		return icss_iep_pps_enable(iep, on);
+	case PTP_CLK_REQ_EXTTS:
+		return icss_iep_extts_enable(iep, rq->extts.index, on);
+	default:
+		break;
+	}
+
+	return -EOPNOTSUPP;
+}
+
+static struct ptp_clock_info icss_iep_ptp_info = {
+	.owner		= THIS_MODULE,
+	.name		= "ICSS IEP timer",
+	.max_adj	= 10000000,
+	.adjfine	= icss_iep_ptp_adjfine,
+	.adjtime	= icss_iep_ptp_adjtime,
+	.gettimex64	= icss_iep_ptp_gettimeex,
+	.settime64	= icss_iep_ptp_settime,
+	.enable		= icss_iep_ptp_enable,
+};
+
+struct icss_iep *icss_iep_get_idx(struct device_node *np, int idx)
+{
+	struct platform_device *pdev;
+	struct device_node *iep_np;
+	struct icss_iep *iep;
+
+	iep_np = of_parse_phandle(np, "ti,iep", idx);
+	if (!iep_np || !of_device_is_available(iep_np))
+		return ERR_PTR(-ENODEV);
+
+	pdev = of_find_device_by_node(iep_np);
+	of_node_put(iep_np);
+
+	if (!pdev)
+		/* probably IEP not yet probed */
+		return ERR_PTR(-EPROBE_DEFER);
+
+	iep = platform_get_drvdata(pdev);
+	if (!iep)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	device_lock(iep->dev);
+	if (iep->client_np) {
+		device_unlock(iep->dev);
+		dev_err(iep->dev, "IEP is already acquired by %s",
+			iep->client_np->name);
+		return ERR_PTR(-EBUSY);
+	}
+	iep->client_np = np;
+	device_unlock(iep->dev);
+	get_device(iep->dev);
+
+	return iep;
+}
+EXPORT_SYMBOL_GPL(icss_iep_get_idx);
+
+struct icss_iep *icss_iep_get(struct device_node *np)
+{
+	return icss_iep_get_idx(np, 0);
+}
+EXPORT_SYMBOL_GPL(icss_iep_get);
+
+void icss_iep_put(struct icss_iep *iep)
+{
+	device_lock(iep->dev);
+	iep->client_np = NULL;
+	device_unlock(iep->dev);
+	put_device(iep->dev);
+}
+EXPORT_SYMBOL_GPL(icss_iep_put);
+
+int icss_iep_init(struct icss_iep *iep, const struct icss_iep_clockops *clkops,
+		  void *clockops_data, u32 cycle_time_ns)
+{
+	int ret = 0;
+
+	iep->cycle_time_ns = cycle_time_ns;
+	iep->clk_tick_time = iep->def_inc;
+	iep->ops = clkops;
+	iep->clockops_data = clockops_data;
+	icss_iep_set_default_inc(iep, iep->def_inc);
+	icss_iep_set_compensation_inc(iep, iep->def_inc);
+	icss_iep_set_compensation_count(iep, 0);
+	regmap_write(iep->map, ICSS_IEP_SYNC_PWIDTH_REG, iep->refclk_freq / 10); /* 100 ms pulse */
+	regmap_write(iep->map, ICSS_IEP_SYNC0_PERIOD_REG, 0);
+	if (iep->plat_data->flags & ICSS_IEP_SLOW_COMPEN_REG_SUPPORT)
+		icss_iep_set_slow_compensation_count(iep, 0);
+
+	if (!(iep->plat_data->flags & ICSS_IEP_64BIT_COUNTER_SUPPORT) ||
+	    !(iep->plat_data->flags & ICSS_IEP_SLOW_COMPEN_REG_SUPPORT))
+		goto skip_perout;
+
+	if (iep->ops && iep->ops->perout_enable) {
+		iep->ptp_info.n_per_out = 1;
+		iep->ptp_info.pps = 1;
+	}
+
+	if (iep->ops && iep->ops->extts_enable)
+		iep->ptp_info.n_ext_ts = 2;
+
+skip_perout:
+	if (cycle_time_ns)
+		icss_iep_enable_shadow_mode(iep);
+	else
+		icss_iep_enable(iep);
+	icss_iep_settime(iep, ktime_get_real_ns());
+
+	iep->ptp_clock = ptp_clock_register(&iep->ptp_info, iep->dev);
+	if (IS_ERR(iep->ptp_clock)) {
+		ret = PTR_ERR(iep->ptp_clock);
+		iep->ptp_clock = NULL;
+		dev_err(iep->dev, "Failed to register ptp clk %d\n", ret);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(icss_iep_init);
+
+int icss_iep_exit(struct icss_iep *iep)
+{
+	if (iep->ptp_clock) {
+		ptp_clock_unregister(iep->ptp_clock);
+		iep->ptp_clock = NULL;
+	}
+	icss_iep_disable(iep);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(icss_iep_exit);
+
+static int icss_iep_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct icss_iep *iep;
+	struct clk *iep_clk;
+
+	iep = devm_kzalloc(dev, sizeof(*iep), GFP_KERNEL);
+	if (!iep)
+		return -ENOMEM;
+
+	iep->dev = dev;
+	iep->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(iep->base))
+		return -ENODEV;
+
+	iep_clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(iep_clk))
+		return PTR_ERR(iep_clk);
+
+	iep->refclk_freq = clk_get_rate(iep_clk);
+
+	iep->def_inc = NSEC_PER_SEC / iep->refclk_freq;	/* ns per clock tick */
+	if (iep->def_inc > IEP_MAX_DEF_INC) {
+		dev_err(dev, "Failed to set def_inc %d.  IEP_clock is too slow to be supported\n",
+			iep->def_inc);
+		return -EINVAL;
+	}
+
+	iep->plat_data = device_get_match_data(dev);
+	if (!iep->plat_data)
+		return -EINVAL;
+
+	iep->map = devm_regmap_init(dev, NULL, iep, iep->plat_data->config);
+	if (IS_ERR(iep->map)) {
+		dev_err(dev, "Failed to create regmap for IEP %ld\n",
+			PTR_ERR(iep->map));
+		return PTR_ERR(iep->map);
+	}
+
+	iep->ptp_info = icss_iep_ptp_info;
+	mutex_init(&iep->ptp_clk_mutex);
+	spin_lock_init(&iep->irq_lock);
+	dev_set_drvdata(dev, iep);
+	icss_iep_disable(iep);
+
+	return 0;
+}
+
+static bool am654_icss_iep_valid_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case ICSS_IEP_GLOBAL_CFG_REG ... ICSS_IEP_SYNC_START_REG:
+		return true;
+	default:
+		return false;
+	}
+
+	return false;
+}
+
+static int icss_iep_regmap_write(void *context, unsigned int reg,
+				 unsigned int val)
+{
+	struct icss_iep *iep = context;
+
+	writel(val, iep->base + iep->plat_data->reg_offs[reg]);
+
+	return 0;
+}
+
+static int icss_iep_regmap_read(void *context, unsigned int reg,
+				unsigned int *val)
+{
+	struct icss_iep *iep = context;
+
+	*val = readl(iep->base + iep->plat_data->reg_offs[reg]);
+
+	return 0;
+}
+
+static struct regmap_config am654_icss_iep_regmap_config = {
+	.name = "icss iep",
+	.reg_stride = 1,
+	.reg_write = icss_iep_regmap_write,
+	.reg_read = icss_iep_regmap_read,
+	.writeable_reg = am654_icss_iep_valid_reg,
+	.readable_reg = am654_icss_iep_valid_reg,
+	.fast_io = 1,
+};
+
+static const struct icss_iep_plat_data am654_icss_iep_plat_data = {
+	.flags = ICSS_IEP_64BIT_COUNTER_SUPPORT |
+		 ICSS_IEP_SLOW_COMPEN_REG_SUPPORT |
+		 ICSS_IEP_SHADOW_MODE_SUPPORT,
+	.reg_offs = {
+		[ICSS_IEP_GLOBAL_CFG_REG] = 0x00,
+		[ICSS_IEP_COMPEN_REG] = 0x08,
+		[ICSS_IEP_SLOW_COMPEN_REG] = 0x0C,
+		[ICSS_IEP_COUNT_REG0] = 0x10,
+		[ICSS_IEP_COUNT_REG1] = 0x14,
+		[ICSS_IEP_CAPTURE_CFG_REG] = 0x18,
+		[ICSS_IEP_CAPTURE_STAT_REG] = 0x1c,
+
+		[ICSS_IEP_CAP6_RISE_REG0] = 0x50,
+		[ICSS_IEP_CAP6_RISE_REG1] = 0x54,
+
+		[ICSS_IEP_CAP7_RISE_REG0] = 0x60,
+		[ICSS_IEP_CAP7_RISE_REG1] = 0x64,
+
+		[ICSS_IEP_CMP_CFG_REG] = 0x70,
+		[ICSS_IEP_CMP_STAT_REG] = 0x74,
+		[ICSS_IEP_CMP0_REG0] = 0x78,
+		[ICSS_IEP_CMP0_REG1] = 0x7c,
+		[ICSS_IEP_CMP1_REG0] = 0x80,
+		[ICSS_IEP_CMP1_REG1] = 0x84,
+
+		[ICSS_IEP_CMP8_REG0] = 0xc0,
+		[ICSS_IEP_CMP8_REG1] = 0xc4,
+		[ICSS_IEP_SYNC_CTRL_REG] = 0x180,
+		[ICSS_IEP_SYNC0_STAT_REG] = 0x188,
+		[ICSS_IEP_SYNC1_STAT_REG] = 0x18c,
+		[ICSS_IEP_SYNC_PWIDTH_REG] = 0x190,
+		[ICSS_IEP_SYNC0_PERIOD_REG] = 0x194,
+		[ICSS_IEP_SYNC1_DELAY_REG] = 0x198,
+		[ICSS_IEP_SYNC_START_REG] = 0x19c,
+	},
+	.config = &am654_icss_iep_regmap_config,
+};
+
+static const struct of_device_id icss_iep_of_match[] = {
+	{
+		.compatible = "ti,am654-icss-iep",
+		.data = &am654_icss_iep_plat_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, icss_iep_of_match);
+
+static struct platform_driver icss_iep_driver = {
+	.driver = {
+		.name = "icss-iep",
+		.of_match_table = icss_iep_of_match,
+	},
+	.probe = icss_iep_probe,
+};
+module_platform_driver(icss_iep_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TI ICSS IEP driver");
+MODULE_AUTHOR("Roger Quadros <rogerq@ti.com>");
+MODULE_AUTHOR("Md Danish Anwar <danishanwar@ti.com>");

drivers/net/ethernet/ti/icssg/icss_iep.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Texas Instruments ICSSG Industrial Ethernet Peripheral (IEP) Driver
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ *
+ */
+
+#ifndef __NET_TI_ICSS_IEP_H
+#define __NET_TI_ICSS_IEP_H
+
+#include <linux/mutex.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/regmap.h>
+
+struct icss_iep;
+
+/* Firmware specific clock operations */
+struct icss_iep_clockops {
+	void (*settime)(void *clockops_data, u64 ns);
+	void (*adjtime)(void *clockops_data, s64 delta);
+	u64 (*gettime)(void *clockops_data, struct ptp_system_timestamp *sts);
+	int (*perout_enable)(void *clockops_data,
+			     struct ptp_perout_request *req, int on,
+			     u64 *cmp);
+	int (*extts_enable)(void *clockops_data, u32 index, int on);
+};
+
+struct icss_iep *icss_iep_get(struct device_node *np);
+struct icss_iep *icss_iep_get_idx(struct device_node *np, int idx);
+void icss_iep_put(struct icss_iep *iep);
+int icss_iep_init(struct icss_iep *iep, const struct icss_iep_clockops *clkops,
+		  void *clockops_data, u32 cycle_time_ns);
+int icss_iep_exit(struct icss_iep *iep);
+int icss_iep_get_count_low(struct icss_iep *iep);
+int icss_iep_get_count_hi(struct icss_iep *iep);
+int icss_iep_get_ptp_clock_idx(struct icss_iep *iep);
+
+#endif /* __NET_TI_ICSS_IEP_H */