1 files changed, 551 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-rz-mtu3.c b/drivers/pwm/pwm-rz-mtu3.c
new file mode 100644
index 0000000000..a56cecb0e4
--- /dev/null
+++ b/drivers/pwm/pwm-rz-mtu3.c
@@ -0,0 +1,551 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G2L MTU3a PWM Timer driver
+ *
+ * Copyright (C) 2023 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.
+ * - HW uses one counter and two match components to configure duty_cycle
+ *   and period.
+ * - Multi-Function Timer Pulse Unit (a.k.a MTU) has 7 HW channels for PWM
+ *   operations. (The channels are MTU{0..4, 6, 7}.)
+ * - MTU{1, 2} channels have a single IO, whereas all other HW channels have
+ *   2 IOs.
+ * - Each IO is modelled as an independent PWM channel.
+ * - rz_mtu3_channel_io_map table is used to map the PWM channel to the
+ *   corresponding HW channel as there are difference in number of IOs
+ *   between HW channels.
+ */
+
+#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_MAX_PWM_CHANNELS	12
+#define RZ_MTU3_MAX_HW_CHANNELS		7
+
+/**
+ * struct rz_mtu3_channel_io_map - MTU3 pwm channel map
+ *
+ * @base_pwm_number: First PWM of a channel
+ * @num_channel_ios: number of IOs on the HW channel.
+ */
+struct rz_mtu3_channel_io_map {
+	u8 base_pwm_number;
+	u8 num_channel_ios;
+};
+
+/**
+ * struct rz_mtu3_pwm_channel - MTU3 pwm channel data
+ *
+ * @mtu: MTU3 channel data
+ * @map: MTU3 pwm channel map
+ */
+struct rz_mtu3_pwm_channel {
+	struct rz_mtu3_channel *mtu;
+	const struct rz_mtu3_channel_io_map *map;
+};
+
+/**
+ * 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
+ * @enable_count: MTU3 enable count
+ * @prescale: MTU3 prescale
+ * @channel_data: MTU3 pwm channel data
+ */
+
+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_CHANNELS];
+	u32 enable_count[RZ_MTU3_MAX_HW_CHANNELS];
+	u8 prescale[RZ_MTU3_MAX_HW_CHANNELS];
+	struct rz_mtu3_pwm_channel channel_data[RZ_MTU3_MAX_HW_CHANNELS];
+};
+
+/*
+ * The MTU channels are {0..4, 6, 7} and the number of IO on MTU1
+ * and MTU2 channel is 1 compared to 2 on others.
+ */
+static const struct rz_mtu3_channel_io_map channel_map[] = {
+	{ 0, 2 }, { 2, 1 }, { 3, 1 }, { 4, 2 }, { 6, 2 }, { 8, 2 }, { 10, 2 }
+};
+
+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 void rz_mtu3_pwm_read_tgr_registers(struct rz_mtu3_pwm_channel *priv,
+					   u16 reg_pv_offset, u16 *pv_val,
+					   u16 reg_dc_offset, u16 *dc_val)
+{
+	*pv_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_pv_offset);
+	*dc_val = rz_mtu3_16bit_ch_read(priv->mtu, reg_dc_offset);
+}
+
+static void rz_mtu3_pwm_write_tgr_registers(struct rz_mtu3_pwm_channel *priv,
+					    u16 reg_pv_offset, u16 pv_val,
+					    u16 reg_dc_offset, u16 dc_val)
+{
+	rz_mtu3_16bit_ch_write(priv->mtu, reg_pv_offset, pv_val);
+	rz_mtu3_16bit_ch_write(priv->mtu, reg_dc_offset, dc_val);
+}
+
+static u8 rz_mtu3_pwm_calculate_prescale(struct rz_mtu3_pwm_chip *rz_mtu3,
+					 u64 period_cycles)
+{
+	u32 prescaled_period_cycles;
+	u8 prescale;
+
+	/*
+	 * Supported prescale values are 1, 4, 16 and 64.
+	 * TODO: Support prescale values 2, 8, 32, 256 and 1024.
+	 */
+	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_pwm_channel *
+rz_mtu3_get_channel(struct rz_mtu3_pwm_chip *rz_mtu3_pwm, u32 hwpwm)
+{
+	struct rz_mtu3_pwm_channel *priv = rz_mtu3_pwm->channel_data;
+	unsigned int ch;
+
+	for (ch = 0; ch < RZ_MTU3_MAX_HW_CHANNELS; ch++, priv++) {
+		if (priv->map->base_pwm_number + priv->map->num_channel_ios > hwpwm)
+			break;
+	}
+
+	return priv;
+}
+
+static bool rz_mtu3_pwm_is_ch_enabled(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+				      u32 hwpwm)
+{
+	struct rz_mtu3_pwm_channel *priv;
+	bool is_channel_en;
+	u8 val;
+
+	priv = rz_mtu3_get_channel(rz_mtu3_pwm, hwpwm);
+	is_channel_en = rz_mtu3_is_enabled(priv->mtu);
+	if (!is_channel_en)
+		return false;
+
+	if (priv->map->base_pwm_number == hwpwm)
+		val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORH);
+	else
+		val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TIORL);
+
+	return val & RZ_MTU3_TIOR_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_pwm_channel *priv;
+	bool is_mtu3_channel_available;
+	u32 ch;
+
+	priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch = priv - rz_mtu3_pwm->channel_data;
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	/*
+	 * Each channel must be requested only once, so if the channel
+	 * serves two PWMs and the other is already requested, skip over
+	 * rz_mtu3_request_channel()
+	 */
+	if (!rz_mtu3_pwm->user_count[ch]) {
+		is_mtu3_channel_available = rz_mtu3_request_channel(priv->mtu);
+		if (!is_mtu3_channel_available) {
+			mutex_unlock(&rz_mtu3_pwm->lock);
+			return -EBUSY;
+		}
+	}
+
+	rz_mtu3_pwm->user_count[ch]++;
+	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_pwm_channel *priv;
+	u32 ch;
+
+	priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch = priv - rz_mtu3_pwm->channel_data;
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	rz_mtu3_pwm->user_count[ch]--;
+	if (!rz_mtu3_pwm->user_count[ch])
+		rz_mtu3_release_channel(priv->mtu);
+
+	mutex_unlock(&rz_mtu3_pwm->lock);
+}
+
+static int rz_mtu3_pwm_enable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+			      struct pwm_device *pwm)
+{
+	struct rz_mtu3_pwm_channel *priv;
+	u32 ch;
+	u8 val;
+	int rc;
+
+	rc = pm_runtime_resume_and_get(rz_mtu3_pwm->chip.dev);
+	if (rc)
+		return rc;
+
+	priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch = priv - rz_mtu3_pwm->channel_data;
+	val = RZ_MTU3_TIOR_OC_IOB_TOGGLE | RZ_MTU3_TIOR_OC_IOA_H_COMP_MATCH;
+
+	rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_MD_PWMMODE1);
+	if (priv->map->base_pwm_number == pwm->hwpwm)
+		rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, val);
+	else
+		rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, val);
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	if (!rz_mtu3_pwm->enable_count[ch])
+		rz_mtu3_enable(priv->mtu);
+
+	rz_mtu3_pwm->enable_count[ch]++;
+	mutex_unlock(&rz_mtu3_pwm->lock);
+
+	return 0;
+}
+
+static void rz_mtu3_pwm_disable(struct rz_mtu3_pwm_chip *rz_mtu3_pwm,
+				struct pwm_device *pwm)
+{
+	struct rz_mtu3_pwm_channel *priv;
+	u32 ch;
+
+	priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch = priv - rz_mtu3_pwm->channel_data;
+
+	/* Disable output pins of MTU3 channel */
+	if (priv->map->base_pwm_number == pwm->hwpwm)
+		rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORH, RZ_MTU3_TIOR_OC_RETAIN);
+	else
+		rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TIORL, RZ_MTU3_TIOR_OC_RETAIN);
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	rz_mtu3_pwm->enable_count[ch]--;
+	if (!rz_mtu3_pwm->enable_count[ch])
+		rz_mtu3_disable(priv->mtu);
+
+	mutex_unlock(&rz_mtu3_pwm->lock);
+
+	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);
+	int rc;
+
+	rc = pm_runtime_resume_and_get(chip->dev);
+	if (rc)
+		return rc;
+
+	state->enabled = rz_mtu3_pwm_is_ch_enabled(rz_mtu3_pwm, pwm->hwpwm);
+	if (state->enabled) {
+		struct rz_mtu3_pwm_channel *priv;
+		u8 prescale, val;
+		u16 dc, pv;
+		u64 tmp;
+
+		priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
+		if (priv->map->base_pwm_number == pwm->hwpwm)
+			rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRA, &pv,
+						       RZ_MTU3_TGRB, &dc);
+		else
+			rz_mtu3_pwm_read_tgr_registers(priv, RZ_MTU3_TGRC, &pv,
+						       RZ_MTU3_TGRD, &dc);
+
+		val = rz_mtu3_8bit_ch_read(priv->mtu, RZ_MTU3_TCR);
+		prescale = FIELD_GET(RZ_MTU3_TCR_TPCS, val);
+
+		/* With prescale <= 7 and pv <= 0xffff this doesn't overflow. */
+		tmp = NSEC_PER_SEC * (u64)pv << (2 * prescale);
+		state->period = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate);
+		tmp = NSEC_PER_SEC * (u64)dc << (2 * prescale);
+		state->duty_cycle = DIV_ROUND_UP_ULL(tmp, rz_mtu3_pwm->rate);
+
+		if (state->duty_cycle > state->period)
+			state->duty_cycle = state->period;
+	}
+
+	state->polarity = PWM_POLARITY_NORMAL;
+	pm_runtime_put(chip->dev);
+
+	return 0;
+}
+
+static u16 rz_mtu3_pwm_calculate_pv_or_dc(u64 period_or_duty_cycle, u8 prescale)
+{
+	return min(period_or_duty_cycle >> (2 * prescale), (u64)U16_MAX);
+}
+
+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_pwm_channel *priv;
+	u64 period_cycles;
+	u64 duty_cycles;
+	u8 prescale;
+	u16 pv, dc;
+	u8 val;
+	u32 ch;
+
+	priv = rz_mtu3_get_channel(rz_mtu3_pwm, pwm->hwpwm);
+	ch = priv - rz_mtu3_pwm->channel_data;
+
+	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);
+
+	/*
+	 * Prescalar is shared by multiple channels, so prescale can
+	 * NOT be modified when there are multiple channels in use with
+	 * different settings. Modify prescalar if other PWM is off or handle
+	 * it, if current prescale value is less than the one we want to set.
+	 */
+	if (rz_mtu3_pwm->enable_count[ch] > 1) {
+		if (rz_mtu3_pwm->prescale[ch] > prescale)
+			return -EBUSY;
+
+		prescale = rz_mtu3_pwm->prescale[ch];
+	}
+
+	pv = rz_mtu3_pwm_calculate_pv_or_dc(period_cycles, prescale);
+
+	duty_cycles = mul_u64_u32_div(state->duty_cycle, rz_mtu3_pwm->rate,
+				      NSEC_PER_SEC);
+	dc = rz_mtu3_pwm_calculate_pv_or_dc(duty_cycles, prescale);
+
+	/*
+	 * If the PWM channel is disabled, make sure to turn on the clock
+	 * before writing the register.
+	 */
+	if (!pwm->state.enabled) {
+		int rc;
+
+		rc = pm_runtime_resume_and_get(chip->dev);
+		if (rc)
+			return rc;
+	}
+
+	val = RZ_MTU3_TCR_CKEG_RISING | prescale;
+
+	/* Counter must be stopped while updating TCR register */
+	if (rz_mtu3_pwm->prescale[ch] != prescale && rz_mtu3_pwm->enable_count[ch])
+		rz_mtu3_disable(priv->mtu);
+
+	if (priv->map->base_pwm_number == pwm->hwpwm) {
+		rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR,
+				      RZ_MTU3_TCR_CCLR_TGRA | val);
+		rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRA, pv,
+						RZ_MTU3_TGRB, dc);
+	} else {
+		rz_mtu3_8bit_ch_write(priv->mtu, RZ_MTU3_TCR,
+				      RZ_MTU3_TCR_CCLR_TGRC | val);
+		rz_mtu3_pwm_write_tgr_registers(priv, RZ_MTU3_TGRC, pv,
+						RZ_MTU3_TGRD, dc);
+	}
+
+	if (rz_mtu3_pwm->prescale[ch] != prescale) {
+		/*
+		 * Prescalar is shared by multiple channels, we cache the
+		 * prescalar value from first enabled channel and use the same
+		 * value for both channels.
+		 */
+		rz_mtu3_pwm->prescale[ch] = prescale;
+
+		if (rz_mtu3_pwm->enable_count[ch])
+			rz_mtu3_enable(priv->mtu);
+	}
+
+	/* 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;
+	}
+
+	mutex_lock(&rz_mtu3_pwm->lock);
+	ret = rz_mtu3_pwm_config(chip, pwm, state);
+	mutex_unlock(&rz_mtu3_pwm->lock);
+	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);
+
+	return clk_prepare_enable(rz_mtu3_pwm->clk);
+}
+
+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;
+
+	clk_rate_exclusive_put(rz_mtu3_pwm->clk);
+	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 *parent_ddata = dev_get_drvdata(pdev->dev.parent);
+	struct rz_mtu3_pwm_chip *rz_mtu3_pwm;
+	struct device *dev = &pdev->dev;
+	unsigned int i, j = 0;
+	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 = parent_ddata->clk;
+
+	for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) {
+		if (i == RZ_MTU3_CHAN_5 || i == RZ_MTU3_CHAN_8)
+			continue;
+
+		rz_mtu3_pwm->channel_data[j].mtu = &parent_ddata->channels[i];
+		rz_mtu3_pwm->channel_data[j].mtu->dev = dev;
+		rz_mtu3_pwm->channel_data[j].map = &channel_map[j];
+		j++;
+	}
+
+	mutex_init(&rz_mtu3_pwm->lock);
+	platform_set_drvdata(pdev, rz_mtu3_pwm);
+	ret = clk_prepare_enable(rz_mtu3_pwm->clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "Clock enable failed\n");
+
+	clk_rate_exclusive_get(rz_mtu3_pwm->clk);
+
+	rz_mtu3_pwm->rate = clk_get_rate(rz_mtu3_pwm->clk);
+	/*
+	 * Refuse clk rates > 1 GHz to prevent overflow later for computing
+	 * period and duty cycle.
+	 */
+	if (rz_mtu3_pwm->rate > NSEC_PER_SEC) {
+		ret = -EINVAL;
+		clk_rate_exclusive_put(rz_mtu3_pwm->clk);
+		goto disable_clock;
+	}
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	rz_mtu3_pwm->chip.dev = &pdev->dev;
+	ret = devm_add_action_or_reset(&pdev->dev, rz_mtu3_pwm_pm_disable,
+				       rz_mtu3_pwm);
+	if (ret < 0)
+		return ret;
+
+	rz_mtu3_pwm->chip.ops = &rz_mtu3_pwm_ops;
+	rz_mtu3_pwm->chip.npwm = RZ_MTU3_MAX_PWM_CHANNELS;
+	ret = devm_pwmchip_add(&pdev->dev, &rz_mtu3_pwm->chip);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");
+
+	pm_runtime_idle(&pdev->dev);
+
+	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");