[PATCH v12 6/6] pwm: Add Renesas RZ/G2L MTU3a PWM driver

[Biju Das <biju.das.jz@bp.renesas.com>]

Add support for RZ/G2L MTU3a PWM driver. The IP supports
following PWM modes

1) PWM mode{1,2}
2) Reset-synchronized PWM mode
3) Complementary PWM mode{1,2,3}

This patch adds basic pwm mode 1 support for RZ/G2L MTU3a pwm driver
by creating separate logical channels for each IOs.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v11->v12:
 * Updated header file to <linux/mfd/rz-mtu3.h> as core driver is in MFD.
 * Reordered get_state()
v10->v11:
 * No change.
v9->v10:
 * No change.
v8->v9:
 * Added prescale/duty_cycle variables to struct rz_mtu3_pwm_chip and
   cached this values in rz_mtu3_pwm_config and used this cached values
   in get_state(), if PWM is disabled.
 * Added return code for get_state()
v7->v8:
 * Simplified rz_mtu3_pwm_request by calling rz_mtu3_request_channel()
 * Simplified rz_mtu3_pwm_free by calling rz_mtu3_release_channel()
v6->v7:
 * Added channel specific mutex lock to avoid race between counter
   device and rz_mtu3_pwm_{request,free}
 * Added pm_runtime_resume_and_get in rz_mtu3_pwm_enable()
 * Added pm_runtime_put_sync in rz_mtu3_pwm_disable()
 * Updated rz_mtu3_pwm_config()
 * Updated rz_mtu3_pwm_apply()
v5->v6:
 * Updated commit and Kconfig description
 * Sorted the header
 * Replaced dev_get_drvdata from rz_mtu3_pwm_pm_disable()
 * Replaced SET_RUNTIME_PM_OPS->DEFINE_RUNTIME_DEV_PM_OPS and removed
   __maybe_unused from suspend/resume()
v4->v5:
 * pwm device is instantiated by mtu3a core driver.
v3->v4:
 * There is no resource associated with "rz-mtu3-pwm" compatible
   and moved the code to mfd subsystem as it binds against "rz-mtu".
 * Removed struct platform_driver rz_mtu3_pwm_driver.
v2->v3:
 * No change.
v1->v2:
 * Modelled as a single PWM device handling multiple channles.
 * Used PM framework to manage the clocks.
---
 drivers/pwm/Kconfig       |  11 +
 drivers/pwm/Makefile      |   1 +
 drivers/pwm/pwm-rz-mtu3.c | 485 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 497 insertions(+)
 create mode 100644 drivers/pwm/pwm-rz-mtu3.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 31cdc9dae3c5..c54cbeabe093 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -492,6 +492,17 @@ config PWM_ROCKCHIP
 	  Generic PWM framework driver for the PWM controller found on
 	  Rockchip SoCs.
 
+config PWM_RZ_MTU3
+	tristate "Renesas RZ/G2L MTU3a PWM Timer support"
+	depends on RZ_MTU3 || COMPILE_TEST
+	depends on HAS_IOMEM
+	help
+	  This driver exposes the MTU3a PWM Timer controller found in Renesas
+	  RZ/G2L like chips through the PWM API.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-rz-mtu3.
+
 config PWM_SAMSUNG
 	tristate "Samsung PWM support"
 	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index a95aabae9115..6b75c0145336 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_PWM_RCAR)		+= pwm-rcar.o
 obj-$(CONFIG_PWM_RENESAS_TPU)	+= pwm-renesas-tpu.o
 obj-$(CONFIG_PWM_RZV2M)		+= pwm-rzv2m.o
 obj-$(CONFIG_PWM_ROCKCHIP)	+= pwm-rockchip.o
+obj-$(CONFIG_PWM_RZ_MTU3)	+= pwm-rz-mtu3.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
 obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
diff --git a/drivers/pwm/pwm-rz-mtu3.c b/drivers/pwm/pwm-rz-mtu3.c
new file mode 100644
index 000000000000..d94e3fc36dfb
--- /dev/null
+++ b/drivers/pwm/pwm-rz-mtu3.c
@@ -0,0 +1,485 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G2L MTU3a PWM Timer driver
+ *
+ * Copyright (C) 2022 Renesas Electronics Corporation
+ *
+ * Hardware manual for this IP can be found here
+ * https://www.renesas.com/eu/en/document/mah/rzg2l-group-rzg2lc-group-users-manual-hardware-0?language=en
+ *
+ * Limitations:
+ * - When PWM is disabled, the output is driven to Hi-Z.
+ * - While the hardware supports both polarities, the driver (for now)
+ *   only handles normal polarity.
+ * - While the hardware supports pwm mode{1,2}, reset-synchronized pwm and
+ *   complementary pwm modes, the driver (for now) only handles pwm mode1.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/limits.h>
+#include <linux/mfd/rz-mtu3.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pwm.h>
+#include <linux/time.h>
+
+#define RZ_MTU3_TMDR1_MD_NORMAL		(0)
+#define RZ_MTU3_TMDR1_MD_PWM_MODE_1	(2)
+
+#define RZ_MTU3_TIOR_OC_RETAIN		(0)
+#define RZ_MTU3_TIOR_OC_0_H_COMP_MATCH	(2)
+#define RZ_MTU3_TIOR_OC_1_TOGGLE	(7)
+#define RZ_MTU3_TIOR_OC_IOA		GENMASK(3, 0)
+
+#define RZ_MTU3_TCR_CCLR_TGRC		(5 << 5)
+#define RZ_MTU3_TCR_CKEG_RISING		(0 << 3)
+
+#define RZ_MTU3_TCR_TPCS		GENMASK(2, 0)
+
+#define RZ_MTU3_MAX_PWM_MODE1_CHANNELS	(12)
+
+#define RZ_MTU3_MAX_HW_PWM_CHANNELS	(7)
+
+static const u8 rz_mtu3_pwm_mode1_num_ios[] = { 2, 1, 1, 2, 2, 2, 2 };
+
+/**
+ * struct rz_mtu3_pwm_chip - MTU3 pwm private data
+ *
+ * @chip: MTU3 pwm chip data
+ * @clk: MTU3 module clock
+ * @lock: Lock to prevent concurrent access for usage count
+ * @rate: MTU3 clock rate
+ * @user_count: MTU3 usage count
+ * @rz_mtu3_channel: HW channels for the PWM
+ */
+
+struct rz_mtu3_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	struct mutex lock;
+	unsigned long rate;
+	u32 user_count[RZ_MTU3_MAX_HW_PWM_CHANNELS];
+	struct rz_mtu3_channel *ch[RZ_MTU3_MAX_HW_PWM_CHANNELS];
+
+	/*
+	 * The driver cannot read the current duty cycle/prescale from the
+	 * hardware if the hardware is disabled. Cache the last programmed
+	 * duty cycle/prescale value to return in that case.
+	 */
+	u8 prescale[RZ_MTU3_MAX_HW_PWM_CHANNELS];
+	unsigned int duty_cycle[RZ_MTU3_MAX_PWM_MODE1_CHANNELS];
+};
+
+static inline struct rz_mtu3_pwm_chip *to_rz_mtu3_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct rz_mtu3_pwm_chip, chip);
+}
+
+static u8 rz_mtu3_pwm_calculate_prescale(struct rz_mtu3_pwm_chip *rz_mtu3,
+					 u64 period_cycles)
+{
+	u32 prescaled_period_cycles;
+	u8 prescale;
+
+	prescaled_period_cycles = period_cycles >> 16;
+	if (prescaled_period_cycles >= 16)
+		prescale = 3;
+	else
+		prescale = (fls(prescaled_period_cycles) + 1) / 2;
+
+	return prescale;
+}
+
+static struct rz_mtu3_channel *
+rz_mtu3_get_hw_channel(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, u32 channel)
+{
+	unsigned int i, ch_index = 0;
+
+	for (i = 0; i < ARRAY_SIZE(rz_mtu3_pwm_mode1_num_ios); i++) {
+		ch_index += rz_mtu3_pwm_mode1_num_ios[i];
+
+		if (ch_index > channel)
+			break;
+	}
+
+	return rz_mtu3_pwm->ch[i];
+}
+
+static u32 rz_mtu3_get_hw_channel_index(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+					struct rz_mtu3_channel *ch)
+{
+	u32 i;
+
+	for (i = 0; i < ARRAY_SIZE(rz_mtu3_pwm_mode1_num_ios); i++) {
+		if (ch == rz_mtu3_pwm->ch[i])
+			break;
+	}
+
+	return i;
+}
+
+static bool rz_mtu3_pwm_is_second_channel(u32 ch_index, u32 hwpwm)
+{
+	u32 i, pwm_ch_index = 0;
+
+	for (i = 0; i < ch_index; i++)
+		pwm_ch_index += rz_mtu3_pwm_mode1_num_ios[i];
+
+	return pwm_ch_index != hwpwm;
+}
+
+static bool rz_mtu3_pwm_is_ch_enabled(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+				      u32 hwpwm)
+{
+	struct rz_mtu3_channel *ch;
+	bool is_channel_en;
+	u32 ch_index;
+	u8 val;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+	is_channel_en = rz_mtu3_is_enabled(ch);
+
+	if (rz_mtu3_pwm_is_second_channel(ch_index, hwpwm))
+		val = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TIORL);
+	else
+		val = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TIORH);
+
+	return (is_channel_en && (val & RZ_MTU3_TIOR_OC_IOA));
+}
+
+static int rz_mtu3_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
+	struct rz_mtu3_channel *ch;
+	u32 ch_index;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+	if (!rz_mtu3_pwm->user_count[ch_index] && !rz_mtu3_request_channel(ch))
+		return -EBUSY;
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	rz_mtu3_pwm->user_count[ch_index]++;
+	mutex_unlock(&rz_mtu3_pwm->lock);
+
+	return 0;
+}
+
+static void rz_mtu3_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
+	struct rz_mtu3_channel *ch;
+	u32 ch_index;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	rz_mtu3_pwm->user_count[ch_index]--;
+	mutex_unlock(&rz_mtu3_pwm->lock);
+
+	if (!rz_mtu3_pwm->user_count[ch_index])
+		rz_mtu3_release_channel(ch);
+}
+
+static int rz_mtu3_pwm_enable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+			      struct pwm_device *pwm)
+{
+	struct rz_mtu3_channel *ch;
+	u32 ch_index;
+	u8 val;
+	int rc;
+
+	rc = pm_runtime_resume_and_get(rz_mtu3_pwm->chip.dev);
+	if (rc)
+		return rc;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+	val = (RZ_MTU3_TIOR_OC_1_TOGGLE << 4) | RZ_MTU3_TIOR_OC_0_H_COMP_MATCH;
+
+	rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_PWM_MODE_1);
+	if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm))
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORL, val);
+	else
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORH, val);
+
+	if (rz_mtu3_pwm->user_count[ch_index] <= 1)
+		rz_mtu3_enable(ch);
+
+	return 0;
+}
+
+static void rz_mtu3_pwm_disable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+				struct pwm_device *pwm)
+{
+	struct rz_mtu3_channel *ch;
+	u32 ch_index;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+
+	/* Return to normal mode and disable output pins of MTU3 channel */
+	if (rz_mtu3_pwm->user_count[ch_index] <= 1)
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_NORMAL);
+
+	if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm))
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORL, RZ_MTU3_TIOR_OC_RETAIN);
+	else
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIORH, RZ_MTU3_TIOR_OC_RETAIN);
+
+	if (rz_mtu3_pwm->user_count[ch_index] <= 1)
+		rz_mtu3_disable(ch);
+
+	pm_runtime_put_sync(rz_mtu3_pwm->chip.dev);
+}
+
+static int rz_mtu3_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
+	struct rz_mtu3_channel *ch;
+	u8 prescale, val;
+	u32 ch_index;
+	u16 dc, pv;
+	u64 tmp;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+	pm_runtime_get_sync(chip->dev);
+	state->enabled = rz_mtu3_pwm_is_ch_enabled(rz_mtu3_pwm, pwm->hwpwm);
+	if (state->enabled) {
+		val = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TCR);
+		prescale = FIELD_GET(RZ_MTU3_TCR_TPCS, val);
+
+		if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm)) {
+			dc = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRD);
+			pv = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRC);
+		} else {
+			dc = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRB);
+			pv = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TGRA);
+		}
+
+		tmp = NSEC_PER_SEC * (u64)pv << (2 * prescale);
+		state->period = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate);
+	} else {
+		/* If the PWM is disabled, use the cached value. */
+		prescale = rz_mtu3_pwm->prescale[ch_index];
+		dc = rz_mtu3_pwm->duty_cycle[pwm->hwpwm];
+	}
+
+	tmp = NSEC_PER_SEC * (u64)dc << (2 * prescale);
+	state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate);
+	state->polarity = PWM_POLARITY_NORMAL;
+	pm_runtime_put(chip->dev);
+
+	return 0;
+}
+
+static int rz_mtu3_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
+	struct rz_mtu3_channel *ch;
+	unsigned long pv, dc;
+	u64 period_cycles;
+	u64 duty_cycles;
+	u32 ch_index;
+	u8 prescale;
+	int err;
+	u8 val;
+
+	/*
+	 * Refuse clk rates > 1 GHz to prevent overflowing the following
+	 * calculation.
+	 */
+	if (rz_mtu3_pwm->rate > NSEC_PER_SEC)
+		return -EINVAL;
+
+	ch = rz_mtu3_get_hw_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch_index = rz_mtu3_get_hw_channel_index(rz_mtu3_pwm, ch);
+	period_cycles = mul_u64_u32_div(state->period, rz_mtu3_pwm->rate,
+					NSEC_PER_SEC);
+	prescale = rz_mtu3_pwm_calculate_prescale(rz_mtu3_pwm, period_cycles);
+
+	if (period_cycles >> (2 * prescale) <= U16_MAX)
+		pv = period_cycles >> (2 * prescale);
+	else
+		pv = U16_MAX;
+
+	duty_cycles = mul_u64_u32_div(state->duty_cycle, rz_mtu3_pwm->rate,
+				      NSEC_PER_SEC);
+	if (duty_cycles >> (2 * prescale) <= U16_MAX)
+		dc = duty_cycles >> (2 * prescale);
+	else
+		dc = U16_MAX;
+
+	/*
+	 * Store the duty cycle/prescale for future reference in cases where the
+	 * corresponding registers can't be read (i.e. when the PWM is disabled).
+	 */
+	rz_mtu3_pwm->prescale[ch_index] = prescale;
+	rz_mtu3_pwm->duty_cycle[pwm->hwpwm] = dc;
+
+	/*
+	 * If the PWM channel is disabled, make sure to turn on the clock
+	 * before writing the register.
+	 */
+	if (!pwm->state.enabled) {
+		err = pm_runtime_resume_and_get(chip->dev);
+		if (err)
+			return err;
+	}
+
+	val = RZ_MTU3_TCR_CKEG_RISING | prescale;
+	if (rz_mtu3_pwm_is_second_channel(ch_index, pwm->hwpwm)) {
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR,
+				      RZ_MTU3_TCR_CCLR_TGRC | val);
+		rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRD, dc);
+		rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRC, pv);
+	} else {
+		rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR,
+				      RZ_MTU3_TCR_CCLR_TGRA | val);
+		rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRB, dc);
+		rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRA, pv);
+	}
+
+	/* If the PWM is not enabled, turn the clock off again to save power. */
+	if (!pwm->state.enabled)
+		pm_runtime_put(chip->dev);
+
+	return 0;
+}
+
+static int rz_mtu3_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			     const struct pwm_state *state)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = to_rz_mtu3_pwm_chip(chip);
+	bool enabled = pwm->state.enabled;
+	int ret;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	if (!state->enabled) {
+		if (enabled)
+			rz_mtu3_pwm_disable(rz_mtu3_pwm, pwm);
+
+		return 0;
+	}
+
+	ret = rz_mtu3_pwm_config(chip, pwm, state);
+	if (ret)
+		return ret;
+
+	if (!enabled)
+		ret = rz_mtu3_pwm_enable(rz_mtu3_pwm, pwm);
+
+	return ret;
+}
+
+static const struct pwm_ops rz_mtu3_pwm_ops = {
+	.request = rz_mtu3_pwm_request,
+	.free = rz_mtu3_pwm_free,
+	.get_state = rz_mtu3_pwm_get_state,
+	.apply = rz_mtu3_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static int rz_mtu3_pwm_pm_runtime_suspend(struct device *dev)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(rz_mtu3_pwm->clk);
+
+	return 0;
+}
+
+static int rz_mtu3_pwm_pm_runtime_resume(struct device *dev)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = dev_get_drvdata(dev);
+
+	clk_prepare_enable(rz_mtu3_pwm->clk);
+
+	return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(rz_mtu3_pwm_pm_ops,
+				 rz_mtu3_pwm_pm_runtime_suspend,
+				 rz_mtu3_pwm_pm_runtime_resume, NULL);
+
+static void rz_mtu3_pwm_pm_disable(void *data)
+{
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm = data;
+
+	pm_runtime_disable(rz_mtu3_pwm->chip.dev);
+	pm_runtime_set_suspended(rz_mtu3_pwm->chip.dev);
+}
+
+static int rz_mtu3_pwm_probe(struct platform_device *pdev)
+{
+	struct rz_mtu3 *ddata = dev_get_drvdata(pdev->dev.parent);
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm;
+	struct device *dev = &pdev->dev;
+	int num_pwm_hw_ch = 0;
+	unsigned int i;
+	int ret;
+
+	rz_mtu3_pwm = devm_kzalloc(&pdev->dev, sizeof(*rz_mtu3_pwm), GFP_KERNEL);
+	if (!rz_mtu3_pwm)
+		return -ENOMEM;
+
+	rz_mtu3_pwm->clk = ddata->clk;
+	rz_mtu3_pwm->rate = clk_get_rate(rz_mtu3_pwm->clk);
+	for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) {
+		if (i == RZ_MTU5 || i == RZ_MTU8)
+			continue;
+
+		rz_mtu3_pwm->ch[num_pwm_hw_ch] = &ddata->channels[i];
+		rz_mtu3_pwm->ch[num_pwm_hw_ch]->dev = dev;
+		num_pwm_hw_ch++;
+	}
+
+	mutex_init(&rz_mtu3_pwm->lock);
+	platform_set_drvdata(pdev, rz_mtu3_pwm);
+	clk_prepare_enable(rz_mtu3_pwm->clk);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	ret = devm_add_action_or_reset(&pdev->dev,
+				       rz_mtu3_pwm_pm_disable,
+				       rz_mtu3_pwm);
+	if (ret < 0)
+		goto disable_clock;
+
+	rz_mtu3_pwm->chip.dev = &pdev->dev;
+	rz_mtu3_pwm->chip.ops = &rz_mtu3_pwm_ops;
+	rz_mtu3_pwm->chip.npwm = RZ_MTU3_MAX_PWM_MODE1_CHANNELS;
+	ret = devm_pwmchip_add(&pdev->dev, &rz_mtu3_pwm->chip);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");
+		goto disable_clock;
+	}
+
+	return 0;
+
+disable_clock:
+	clk_disable_unprepare(rz_mtu3_pwm->clk);
+	return ret;
+}
+
+static struct platform_driver rz_mtu3_pwm_driver = {
+	.driver = {
+		.name = "pwm-rz-mtu3",
+		.pm = pm_ptr(&rz_mtu3_pwm_pm_ops),
+	},
+	.probe = rz_mtu3_pwm_probe,
+};
+module_platform_driver(rz_mtu3_pwm_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_ALIAS("platform:pwm-rz-mtu3");
+MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a PWM Timer Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1