1 files changed, 573 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
new file mode 100644
index 000000000..2826fc216
--- /dev/null
+++ b/drivers/pwm/pwm-atmel-tcb.c
@@ -0,0 +1,573 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Overkiz SAS 2012
+ *
+ * Author: Boris BREZILLON <b.brezillon@overkiz.com>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <soc/at91/atmel_tcb.h>
+
+#define NPWM	2
+
+#define ATMEL_TC_ACMR_MASK	(ATMEL_TC_ACPA | ATMEL_TC_ACPC |	\
+				 ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG)
+
+#define ATMEL_TC_BCMR_MASK	(ATMEL_TC_BCPB | ATMEL_TC_BCPC |	\
+				 ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG)
+
+struct atmel_tcb_pwm_device {
+	enum pwm_polarity polarity;	/* PWM polarity */
+	unsigned div;			/* PWM clock divider */
+	unsigned duty;			/* PWM duty expressed in clk cycles */
+	unsigned period;		/* PWM period expressed in clk cycles */
+};
+
+struct atmel_tcb_channel {
+	u32 enabled;
+	u32 cmr;
+	u32 ra;
+	u32 rb;
+	u32 rc;
+};
+
+struct atmel_tcb_pwm_chip {
+	struct pwm_chip chip;
+	spinlock_t lock;
+	u8 channel;
+	u8 width;
+	struct regmap *regmap;
+	struct clk *clk;
+	struct clk *gclk;
+	struct clk *slow_clk;
+	struct atmel_tcb_pwm_device *pwms[NPWM];
+	struct atmel_tcb_channel bkup;
+};
+
+static const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128, 0, };
+
+static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct atmel_tcb_pwm_chip, chip);
+}
+
+static int atmel_tcb_pwm_set_polarity(struct pwm_chip *chip,
+				      struct pwm_device *pwm,
+				      enum pwm_polarity polarity)
+{
+	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
+	struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm];
+
+	tcbpwm->polarity = polarity;
+
+	return 0;
+}
+
+static int atmel_tcb_pwm_request(struct pwm_chip *chip,
+				 struct pwm_device *pwm)
+{
+	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
+	struct atmel_tcb_pwm_device *tcbpwm;
+	unsigned cmr;
+	int ret;
+
+	tcbpwm = devm_kzalloc(chip->dev, sizeof(*tcbpwm), GFP_KERNEL);
+	if (!tcbpwm)
+		return -ENOMEM;
+
+	ret = clk_prepare_enable(tcbpwmc->clk);
+	if (ret) {
+		devm_kfree(chip->dev, tcbpwm);
+		return ret;
+	}
+
+	tcbpwm->polarity = PWM_POLARITY_NORMAL;
+	tcbpwm->duty = 0;
+	tcbpwm->period = 0;
+	tcbpwm->div = 0;
+
+	spin_lock(&tcbpwmc->lock);
+	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
+	/*
+	 * Get init config from Timer Counter registers if
+	 * Timer Counter is already configured as a PWM generator.
+	 */
+	if (cmr & ATMEL_TC_WAVE) {
+		if (pwm->hwpwm == 0)
+			regmap_read(tcbpwmc->regmap,
+				    ATMEL_TC_REG(tcbpwmc->channel, RA),
+				    &tcbpwm->duty);
+		else
+			regmap_read(tcbpwmc->regmap,
+				    ATMEL_TC_REG(tcbpwmc->channel, RB),
+				    &tcbpwm->duty);
+
+		tcbpwm->div = cmr & ATMEL_TC_TCCLKS;
+		regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
+			    &tcbpwm->period);
+		cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK |
+			ATMEL_TC_BCMR_MASK);
+	} else
+		cmr = 0;
+
+	cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0;
+	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
+	spin_unlock(&tcbpwmc->lock);
+
+	tcbpwmc->pwms[pwm->hwpwm] = tcbpwm;
+
+	return 0;
+}
+
+static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
+	struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm];
+
+	clk_disable_unprepare(tcbpwmc->clk);
+	tcbpwmc->pwms[pwm->hwpwm] = NULL;
+	devm_kfree(chip->dev, tcbpwm);
+}
+
+static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
+	struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm];
+	unsigned cmr;
+	enum pwm_polarity polarity = tcbpwm->polarity;
+
+	/*
+	 * If duty is 0 the timer will be stopped and we have to
+	 * configure the output correctly on software trigger:
+	 *  - set output to high if PWM_POLARITY_INVERSED
+	 *  - set output to low if PWM_POLARITY_NORMAL
+	 *
+	 * This is why we're reverting polarity in this case.
+	 */
+	if (tcbpwm->duty == 0)
+		polarity = !polarity;
+
+	spin_lock(&tcbpwmc->lock);
+	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
+
+	/* flush old setting and set the new one */
+	if (pwm->hwpwm == 0) {
+		cmr &= ~ATMEL_TC_ACMR_MASK;
+		if (polarity == PWM_POLARITY_INVERSED)
+			cmr |= ATMEL_TC_ASWTRG_CLEAR;
+		else
+			cmr |= ATMEL_TC_ASWTRG_SET;
+	} else {
+		cmr &= ~ATMEL_TC_BCMR_MASK;
+		if (polarity == PWM_POLARITY_INVERSED)
+			cmr |= ATMEL_TC_BSWTRG_CLEAR;
+		else
+			cmr |= ATMEL_TC_BSWTRG_SET;
+	}
+
+	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
+
+	/*
+	 * Use software trigger to apply the new setting.
+	 * If both PWM devices in this group are disabled we stop the clock.
+	 */
+	if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) {
+		regmap_write(tcbpwmc->regmap,
+			     ATMEL_TC_REG(tcbpwmc->channel, CCR),
+			     ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS);
+		tcbpwmc->bkup.enabled = 1;
+	} else {
+		regmap_write(tcbpwmc->regmap,
+			     ATMEL_TC_REG(tcbpwmc->channel, CCR),
+			     ATMEL_TC_SWTRG);
+		tcbpwmc->bkup.enabled = 0;
+	}
+
+	spin_unlock(&tcbpwmc->lock);
+}
+
+static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
+	struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm];
+	u32 cmr;
+	enum pwm_polarity polarity = tcbpwm->polarity;
+
+	/*
+	 * If duty is 0 the timer will be stopped and we have to
+	 * configure the output correctly on software trigger:
+	 *  - set output to high if PWM_POLARITY_INVERSED
+	 *  - set output to low if PWM_POLARITY_NORMAL
+	 *
+	 * This is why we're reverting polarity in this case.
+	 */
+	if (tcbpwm->duty == 0)
+		polarity = !polarity;
+
+	spin_lock(&tcbpwmc->lock);
+	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
+
+	/* flush old setting and set the new one */
+	cmr &= ~ATMEL_TC_TCCLKS;
+
+	if (pwm->hwpwm == 0) {
+		cmr &= ~ATMEL_TC_ACMR_MASK;
+
+		/* Set CMR flags according to given polarity */
+		if (polarity == PWM_POLARITY_INVERSED)
+			cmr |= ATMEL_TC_ASWTRG_CLEAR;
+		else
+			cmr |= ATMEL_TC_ASWTRG_SET;
+	} else {
+		cmr &= ~ATMEL_TC_BCMR_MASK;
+		if (polarity == PWM_POLARITY_INVERSED)
+			cmr |= ATMEL_TC_BSWTRG_CLEAR;
+		else
+			cmr |= ATMEL_TC_BSWTRG_SET;
+	}
+
+	/*
+	 * If duty is 0 or equal to period there's no need to register
+	 * a specific action on RA/RB and RC compare.
+	 * The output will be configured on software trigger and keep
+	 * this config till next config call.
+	 */
+	if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) {
+		if (pwm->hwpwm == 0) {
+			if (polarity == PWM_POLARITY_INVERSED)
+				cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR;
+			else
+				cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET;
+		} else {
+			if (polarity == PWM_POLARITY_INVERSED)
+				cmr |= ATMEL_TC_BCPB_SET | ATMEL_TC_BCPC_CLEAR;
+			else
+				cmr |= ATMEL_TC_BCPB_CLEAR | ATMEL_TC_BCPC_SET;
+		}
+	}
+
+	cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
+
+	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
+
+	if (pwm->hwpwm == 0)
+		regmap_write(tcbpwmc->regmap,
+			     ATMEL_TC_REG(tcbpwmc->channel, RA),
+			     tcbpwm->duty);
+	else
+		regmap_write(tcbpwmc->regmap,
+			     ATMEL_TC_REG(tcbpwmc->channel, RB),
+			     tcbpwm->duty);
+
+	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
+		     tcbpwm->period);
+
+	/* Use software trigger to apply the new setting */
+	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR),
+		     ATMEL_TC_SWTRG | ATMEL_TC_CLKEN);
+	tcbpwmc->bkup.enabled = 1;
+	spin_unlock(&tcbpwmc->lock);
+	return 0;
+}
+
+static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+				int duty_ns, int period_ns)
+{
+	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
+	struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm];
+	struct atmel_tcb_pwm_device *atcbpwm = NULL;
+	int i = 0;
+	int slowclk = 0;
+	unsigned period;
+	unsigned duty;
+	unsigned rate = clk_get_rate(tcbpwmc->clk);
+	unsigned long long min;
+	unsigned long long max;
+
+	/*
+	 * Find best clk divisor:
+	 * the smallest divisor which can fulfill the period_ns requirements.
+	 * If there is a gclk, the first divisor is actually the gclk selector
+	 */
+	if (tcbpwmc->gclk)
+		i = 1;
+	for (; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) {
+		if (atmel_tcb_divisors[i] == 0) {
+			slowclk = i;
+			continue;
+		}
+		min = div_u64((u64)NSEC_PER_SEC * atmel_tcb_divisors[i], rate);
+		max = min << tcbpwmc->width;
+		if (max >= period_ns)
+			break;
+	}
+
+	/*
+	 * If none of the divisor are small enough to represent period_ns
+	 * take slow clock (32KHz).
+	 */
+	if (i == ARRAY_SIZE(atmel_tcb_divisors)) {
+		i = slowclk;
+		rate = clk_get_rate(tcbpwmc->slow_clk);
+		min = div_u64(NSEC_PER_SEC, rate);
+		max = min << tcbpwmc->width;
+
+		/* If period is too big return ERANGE error */
+		if (max < period_ns)
+			return -ERANGE;
+	}
+
+	duty = div_u64(duty_ns, min);
+	period = div_u64(period_ns, min);
+
+	if (pwm->hwpwm == 0)
+		atcbpwm = tcbpwmc->pwms[1];
+	else
+		atcbpwm = tcbpwmc->pwms[0];
+
+	/*
+	 * PWM devices provided by the TCB driver are grouped by 2.
+	 * PWM devices in a given group must be configured with the
+	 * same period_ns.
+	 *
+	 * We're checking the period value of the second PWM device
+	 * in this group before applying the new config.
+	 */
+	if ((atcbpwm && atcbpwm->duty > 0 &&
+			atcbpwm->duty != atcbpwm->period) &&
+		(atcbpwm->div != i || atcbpwm->period != period)) {
+		dev_err(chip->dev,
+			"failed to configure period_ns: PWM group already configured with a different value\n");
+		return -EINVAL;
+	}
+
+	tcbpwm->period = period;
+	tcbpwm->div = i;
+	tcbpwm->duty = duty;
+
+	return 0;
+}
+
+static int atmel_tcb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			       const struct pwm_state *state)
+{
+	int duty_cycle, period;
+	int ret;
+
+	/* This function only sets a flag in driver data */
+	atmel_tcb_pwm_set_polarity(chip, pwm, state->polarity);
+
+	if (!state->enabled) {
+		atmel_tcb_pwm_disable(chip, pwm);
+		return 0;
+	}
+
+	period = state->period < INT_MAX ? state->period : INT_MAX;
+	duty_cycle = state->duty_cycle < INT_MAX ? state->duty_cycle : INT_MAX;
+
+	ret = atmel_tcb_pwm_config(chip, pwm, duty_cycle, period);
+	if (ret)
+		return ret;
+
+	return atmel_tcb_pwm_enable(chip, pwm);
+}
+
+static const struct pwm_ops atmel_tcb_pwm_ops = {
+	.request = atmel_tcb_pwm_request,
+	.free = atmel_tcb_pwm_free,
+	.apply = atmel_tcb_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static struct atmel_tcb_config tcb_rm9200_config = {
+	.counter_width = 16,
+};
+
+static struct atmel_tcb_config tcb_sam9x5_config = {
+	.counter_width = 32,
+};
+
+static struct atmel_tcb_config tcb_sama5d2_config = {
+	.counter_width = 32,
+	.has_gclk = 1,
+};
+
+static const struct of_device_id atmel_tcb_of_match[] = {
+	{ .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
+	{ .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
+	{ .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
+	{ /* sentinel */ }
+};
+
+static int atmel_tcb_pwm_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct atmel_tcb_pwm_chip *tcbpwm;
+	const struct atmel_tcb_config *config;
+	struct device_node *np = pdev->dev.of_node;
+	char clk_name[] = "t0_clk";
+	int err;
+	int channel;
+
+	tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
+	if (tcbpwm == NULL)
+		return -ENOMEM;
+
+	err = of_property_read_u32(np, "reg", &channel);
+	if (err < 0) {
+		dev_err(&pdev->dev,
+			"failed to get Timer Counter Block channel from device tree (error: %d)\n",
+			err);
+		return err;
+	}
+
+	tcbpwm->regmap = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(tcbpwm->regmap))
+		return PTR_ERR(tcbpwm->regmap);
+
+	tcbpwm->slow_clk = of_clk_get_by_name(np->parent, "slow_clk");
+	if (IS_ERR(tcbpwm->slow_clk))
+		return PTR_ERR(tcbpwm->slow_clk);
+
+	clk_name[1] += channel;
+	tcbpwm->clk = of_clk_get_by_name(np->parent, clk_name);
+	if (IS_ERR(tcbpwm->clk))
+		tcbpwm->clk = of_clk_get_by_name(np->parent, "t0_clk");
+	if (IS_ERR(tcbpwm->clk)) {
+		err = PTR_ERR(tcbpwm->clk);
+		goto err_slow_clk;
+	}
+
+	match = of_match_node(atmel_tcb_of_match, np->parent);
+	config = match->data;
+
+	if (config->has_gclk) {
+		tcbpwm->gclk = of_clk_get_by_name(np->parent, "gclk");
+		if (IS_ERR(tcbpwm->gclk)) {
+			err = PTR_ERR(tcbpwm->gclk);
+			goto err_clk;
+		}
+	}
+
+	tcbpwm->chip.dev = &pdev->dev;
+	tcbpwm->chip.ops = &atmel_tcb_pwm_ops;
+	tcbpwm->chip.npwm = NPWM;
+	tcbpwm->channel = channel;
+	tcbpwm->width = config->counter_width;
+
+	err = clk_prepare_enable(tcbpwm->slow_clk);
+	if (err)
+		goto err_gclk;
+
+	spin_lock_init(&tcbpwm->lock);
+
+	err = pwmchip_add(&tcbpwm->chip);
+	if (err < 0)
+		goto err_disable_clk;
+
+	platform_set_drvdata(pdev, tcbpwm);
+
+	return 0;
+
+err_disable_clk:
+	clk_disable_unprepare(tcbpwm->slow_clk);
+
+err_gclk:
+	clk_put(tcbpwm->gclk);
+
+err_clk:
+	clk_put(tcbpwm->clk);
+
+err_slow_clk:
+	clk_put(tcbpwm->slow_clk);
+
+	return err;
+}
+
+static void atmel_tcb_pwm_remove(struct platform_device *pdev)
+{
+	struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
+
+	pwmchip_remove(&tcbpwm->chip);
+
+	clk_disable_unprepare(tcbpwm->slow_clk);
+	clk_put(tcbpwm->gclk);
+	clk_put(tcbpwm->clk);
+	clk_put(tcbpwm->slow_clk);
+}
+
+static const struct of_device_id atmel_tcb_pwm_dt_ids[] = {
+	{ .compatible = "atmel,tcb-pwm", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids);
+
+#ifdef CONFIG_PM_SLEEP
+static int atmel_tcb_pwm_suspend(struct device *dev)
+{
+	struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev);
+	struct atmel_tcb_channel *chan = &tcbpwm->bkup;
+	unsigned int channel = tcbpwm->channel;
+
+	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), &chan->cmr);
+	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), &chan->ra);
+	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), &chan->rb);
+	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), &chan->rc);
+
+	return 0;
+}
+
+static int atmel_tcb_pwm_resume(struct device *dev)
+{
+	struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev);
+	struct atmel_tcb_channel *chan = &tcbpwm->bkup;
+	unsigned int channel = tcbpwm->channel;
+
+	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), chan->cmr);
+	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), chan->ra);
+	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), chan->rb);
+	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), chan->rc);
+
+	if (chan->enabled)
+		regmap_write(tcbpwm->regmap,
+			     ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
+			     ATMEL_TC_REG(channel, CCR));
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(atmel_tcb_pwm_pm_ops, atmel_tcb_pwm_suspend,
+			 atmel_tcb_pwm_resume);
+
+static struct platform_driver atmel_tcb_pwm_driver = {
+	.driver = {
+		.name = "atmel-tcb-pwm",
+		.of_match_table = atmel_tcb_pwm_dt_ids,
+		.pm = &atmel_tcb_pwm_pm_ops,
+	},
+	.probe = atmel_tcb_pwm_probe,
+	.remove_new = atmel_tcb_pwm_remove,
+};
+module_platform_driver(atmel_tcb_pwm_driver);
+
+MODULE_AUTHOR("Boris BREZILLON <b.brezillon@overkiz.com>");
+MODULE_DESCRIPTION("Atmel Timer Counter Pulse Width Modulation Driver");
+MODULE_LICENSE("GPL v2");