Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 419 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
new file mode 100644
index 000000000..530d7dc5f
--- /dev/null
+++ b/drivers/pwm/pwm-atmel.c
@@ -0,0 +1,419 @@
+/*
+ * Driver for Atmel Pulse Width Modulation Controller
+ *
+ * Copyright (C) 2013 Atmel Corporation
+ *		 Bo Shen <voice.shen@atmel.com>
+ *
+ * Licensed under GPLv2.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+
+/* The following is global registers for PWM controller */
+#define PWM_ENA			0x04
+#define PWM_DIS			0x08
+#define PWM_SR			0x0C
+#define PWM_ISR			0x1C
+/* Bit field in SR */
+#define PWM_SR_ALL_CH_ON	0x0F
+
+/* The following register is PWM channel related registers */
+#define PWM_CH_REG_OFFSET	0x200
+#define PWM_CH_REG_SIZE		0x20
+
+#define PWM_CMR			0x0
+/* Bit field in CMR */
+#define PWM_CMR_CPOL		(1 << 9)
+#define PWM_CMR_UPD_CDTY	(1 << 10)
+#define PWM_CMR_CPRE_MSK	0xF
+
+/* The following registers for PWM v1 */
+#define PWMV1_CDTY		0x04
+#define PWMV1_CPRD		0x08
+#define PWMV1_CUPD		0x10
+
+/* The following registers for PWM v2 */
+#define PWMV2_CDTY		0x04
+#define PWMV2_CDTYUPD		0x08
+#define PWMV2_CPRD		0x0C
+#define PWMV2_CPRDUPD		0x10
+
+/*
+ * Max value for duty and period
+ *
+ * Although the duty and period register is 32 bit,
+ * however only the LSB 16 bits are significant.
+ */
+#define PWM_MAX_DTY		0xFFFF
+#define PWM_MAX_PRD		0xFFFF
+#define PRD_MAX_PRES		10
+
+struct atmel_pwm_registers {
+	u8 period;
+	u8 period_upd;
+	u8 duty;
+	u8 duty_upd;
+};
+
+struct atmel_pwm_chip {
+	struct pwm_chip chip;
+	struct clk *clk;
+	void __iomem *base;
+	const struct atmel_pwm_registers *regs;
+
+	unsigned int updated_pwms;
+	/* ISR is cleared when read, ensure only one thread does that */
+	struct mutex isr_lock;
+};
+
+static inline struct atmel_pwm_chip *to_atmel_pwm_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct atmel_pwm_chip, chip);
+}
+
+static inline u32 atmel_pwm_readl(struct atmel_pwm_chip *chip,
+				  unsigned long offset)
+{
+	return readl_relaxed(chip->base + offset);
+}
+
+static inline void atmel_pwm_writel(struct atmel_pwm_chip *chip,
+				    unsigned long offset, unsigned long val)
+{
+	writel_relaxed(val, chip->base + offset);
+}
+
+static inline u32 atmel_pwm_ch_readl(struct atmel_pwm_chip *chip,
+				     unsigned int ch, unsigned long offset)
+{
+	unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE;
+
+	return readl_relaxed(chip->base + base + offset);
+}
+
+static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip,
+				       unsigned int ch, unsigned long offset,
+				       unsigned long val)
+{
+	unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE;
+
+	writel_relaxed(val, chip->base + base + offset);
+}
+
+static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
+					     const struct pwm_state *state,
+					     unsigned long *cprd, u32 *pres)
+{
+	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+	unsigned long long cycles = state->period;
+
+	/* Calculate the period cycles and prescale value */
+	cycles *= clk_get_rate(atmel_pwm->clk);
+	do_div(cycles, NSEC_PER_SEC);
+
+	for (*pres = 0; cycles > PWM_MAX_PRD; cycles >>= 1)
+		(*pres)++;
+
+	if (*pres > PRD_MAX_PRES) {
+		dev_err(chip->dev, "pres exceeds the maximum value\n");
+		return -EINVAL;
+	}
+
+	*cprd = cycles;
+
+	return 0;
+}
+
+static void atmel_pwm_calculate_cdty(const struct pwm_state *state,
+				     unsigned long cprd, unsigned long *cdty)
+{
+	unsigned long long cycles = state->duty_cycle;
+
+	cycles *= cprd;
+	do_div(cycles, state->period);
+	*cdty = cprd - cycles;
+}
+
+static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,
+				  unsigned long cdty)
+{
+	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+	u32 val;
+
+	if (atmel_pwm->regs->duty_upd ==
+	    atmel_pwm->regs->period_upd) {
+		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+		val &= ~PWM_CMR_UPD_CDTY;
+		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
+	}
+
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
+			    atmel_pwm->regs->duty_upd, cdty);
+}
+
+static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
+				    struct pwm_device *pwm,
+				    unsigned long cprd, unsigned long cdty)
+{
+	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
+			    atmel_pwm->regs->duty, cdty);
+	atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
+			    atmel_pwm->regs->period, cprd);
+}
+
+static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,
+			      bool disable_clk)
+{
+	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+	unsigned long timeout = jiffies + 2 * HZ;
+
+	/*
+	 * Wait for at least a complete period to have passed before disabling a
+	 * channel to be sure that CDTY has been updated
+	 */
+	mutex_lock(&atmel_pwm->isr_lock);
+	atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+
+	while (!(atmel_pwm->updated_pwms & (1 << pwm->hwpwm)) &&
+	       time_before(jiffies, timeout)) {
+		usleep_range(10, 100);
+		atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+	}
+
+	mutex_unlock(&atmel_pwm->isr_lock);
+	atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm);
+
+	/*
+	 * Wait for the PWM channel disable operation to be effective before
+	 * stopping the clock.
+	 */
+	timeout = jiffies + 2 * HZ;
+
+	while ((atmel_pwm_readl(atmel_pwm, PWM_SR) & (1 << pwm->hwpwm)) &&
+	       time_before(jiffies, timeout))
+		usleep_range(10, 100);
+
+	if (disable_clk)
+		clk_disable(atmel_pwm->clk);
+}
+
+static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			   struct pwm_state *state)
+{
+	struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+	struct pwm_state cstate;
+	unsigned long cprd, cdty;
+	u32 pres, val;
+	int ret;
+
+	pwm_get_state(pwm, &cstate);
+
+	if (state->enabled) {
+		if (cstate.enabled &&
+		    cstate.polarity == state->polarity &&
+		    cstate.period == state->period) {
+			cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
+						  atmel_pwm->regs->period);
+			atmel_pwm_calculate_cdty(state, cprd, &cdty);
+			atmel_pwm_update_cdty(chip, pwm, cdty);
+			return 0;
+		}
+
+		ret = atmel_pwm_calculate_cprd_and_pres(chip, state, &cprd,
+							&pres);
+		if (ret) {
+			dev_err(chip->dev,
+				"failed to calculate cprd and prescaler\n");
+			return ret;
+		}
+
+		atmel_pwm_calculate_cdty(state, cprd, &cdty);
+
+		if (cstate.enabled) {
+			atmel_pwm_disable(chip, pwm, false);
+		} else {
+			ret = clk_enable(atmel_pwm->clk);
+			if (ret) {
+				dev_err(chip->dev, "failed to enable clock\n");
+				return ret;
+			}
+		}
+
+		/* It is necessary to preserve CPOL, inside CMR */
+		val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+		val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK);
+		if (state->polarity == PWM_POLARITY_NORMAL)
+			val &= ~PWM_CMR_CPOL;
+		else
+			val |= PWM_CMR_CPOL;
+		atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
+		atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty);
+		mutex_lock(&atmel_pwm->isr_lock);
+		atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+		atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm);
+		mutex_unlock(&atmel_pwm->isr_lock);
+		atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);
+	} else if (cstate.enabled) {
+		atmel_pwm_disable(chip, pwm, true);
+	}
+
+	return 0;
+}
+
+static const struct pwm_ops atmel_pwm_ops = {
+	.apply = atmel_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static const struct atmel_pwm_registers atmel_pwm_regs_v1 = {
+	.period		= PWMV1_CPRD,
+	.period_upd	= PWMV1_CUPD,
+	.duty		= PWMV1_CDTY,
+	.duty_upd	= PWMV1_CUPD,
+};
+
+static const struct atmel_pwm_registers atmel_pwm_regs_v2 = {
+	.period		= PWMV2_CPRD,
+	.period_upd	= PWMV2_CPRDUPD,
+	.duty		= PWMV2_CDTY,
+	.duty_upd	= PWMV2_CDTYUPD,
+};
+
+static const struct platform_device_id atmel_pwm_devtypes[] = {
+	{
+		.name = "at91sam9rl-pwm",
+		.driver_data = (kernel_ulong_t)&atmel_pwm_regs_v1,
+	}, {
+		.name = "sama5d3-pwm",
+		.driver_data = (kernel_ulong_t)&atmel_pwm_regs_v2,
+	}, {
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(platform, atmel_pwm_devtypes);
+
+static const struct of_device_id atmel_pwm_dt_ids[] = {
+	{
+		.compatible = "atmel,at91sam9rl-pwm",
+		.data = &atmel_pwm_regs_v1,
+	}, {
+		.compatible = "atmel,sama5d3-pwm",
+		.data = &atmel_pwm_regs_v2,
+	}, {
+		.compatible = "atmel,sama5d2-pwm",
+		.data = &atmel_pwm_regs_v2,
+	}, {
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
+
+static inline const struct atmel_pwm_registers *
+atmel_pwm_get_driver_data(struct platform_device *pdev)
+{
+	const struct platform_device_id *id;
+
+	if (pdev->dev.of_node)
+		return of_device_get_match_data(&pdev->dev);
+
+	id = platform_get_device_id(pdev);
+
+	return (struct atmel_pwm_registers *)id->driver_data;
+}
+
+static int atmel_pwm_probe(struct platform_device *pdev)
+{
+	const struct atmel_pwm_registers *regs;
+	struct atmel_pwm_chip *atmel_pwm;
+	struct resource *res;
+	int ret;
+
+	regs = atmel_pwm_get_driver_data(pdev);
+	if (!regs)
+		return -ENODEV;
+
+	atmel_pwm = devm_kzalloc(&pdev->dev, sizeof(*atmel_pwm), GFP_KERNEL);
+	if (!atmel_pwm)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	atmel_pwm->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(atmel_pwm->base))
+		return PTR_ERR(atmel_pwm->base);
+
+	atmel_pwm->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(atmel_pwm->clk))
+		return PTR_ERR(atmel_pwm->clk);
+
+	ret = clk_prepare(atmel_pwm->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to prepare PWM clock\n");
+		return ret;
+	}
+
+	atmel_pwm->chip.dev = &pdev->dev;
+	atmel_pwm->chip.ops = &atmel_pwm_ops;
+
+	if (pdev->dev.of_node) {
+		atmel_pwm->chip.of_xlate = of_pwm_xlate_with_flags;
+		atmel_pwm->chip.of_pwm_n_cells = 3;
+	}
+
+	atmel_pwm->chip.base = -1;
+	atmel_pwm->chip.npwm = 4;
+	atmel_pwm->regs = regs;
+	atmel_pwm->updated_pwms = 0;
+	mutex_init(&atmel_pwm->isr_lock);
+
+	ret = pwmchip_add(&atmel_pwm->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add PWM chip %d\n", ret);
+		goto unprepare_clk;
+	}
+
+	platform_set_drvdata(pdev, atmel_pwm);
+
+	return ret;
+
+unprepare_clk:
+	clk_unprepare(atmel_pwm->clk);
+	return ret;
+}
+
+static int atmel_pwm_remove(struct platform_device *pdev)
+{
+	struct atmel_pwm_chip *atmel_pwm = platform_get_drvdata(pdev);
+
+	clk_unprepare(atmel_pwm->clk);
+	mutex_destroy(&atmel_pwm->isr_lock);
+
+	return pwmchip_remove(&atmel_pwm->chip);
+}
+
+static struct platform_driver atmel_pwm_driver = {
+	.driver = {
+		.name = "atmel-pwm",
+		.of_match_table = of_match_ptr(atmel_pwm_dt_ids),
+	},
+	.id_table = atmel_pwm_devtypes,
+	.probe = atmel_pwm_probe,
+	.remove = atmel_pwm_remove,
+};
+module_platform_driver(atmel_pwm_driver);
+
+MODULE_ALIAS("platform:atmel-pwm");
+MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
+MODULE_DESCRIPTION("Atmel PWM driver");
+MODULE_LICENSE("GPL v2");