1 files changed, 549 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c
new file mode 100644
index 0000000000..b7c6045c5d
--- /dev/null
+++ b/drivers/pwm/pwm-fsl-ftm.c
@@ -0,0 +1,549 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Freescale FlexTimer Module (FTM) PWM Driver
+ *
+ *  Copyright 2012-2013 Freescale Semiconductor, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/fsl/ftm.h>
+
+#define FTM_SC_CLK(c)	(((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
+
+enum fsl_pwm_clk {
+	FSL_PWM_CLK_SYS,
+	FSL_PWM_CLK_FIX,
+	FSL_PWM_CLK_EXT,
+	FSL_PWM_CLK_CNTEN,
+	FSL_PWM_CLK_MAX
+};
+
+struct fsl_ftm_soc {
+	bool has_enable_bits;
+};
+
+struct fsl_pwm_periodcfg {
+	enum fsl_pwm_clk clk_select;
+	unsigned int clk_ps;
+	unsigned int mod_period;
+};
+
+struct fsl_pwm_chip {
+	struct pwm_chip chip;
+	struct mutex lock;
+	struct regmap *regmap;
+
+	/* This value is valid iff a pwm is running */
+	struct fsl_pwm_periodcfg period;
+
+	struct clk *ipg_clk;
+	struct clk *clk[FSL_PWM_CLK_MAX];
+
+	const struct fsl_ftm_soc *soc;
+};
+
+static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct fsl_pwm_chip, chip);
+}
+
+static void ftm_clear_write_protection(struct fsl_pwm_chip *fpc)
+{
+	u32 val;
+
+	regmap_read(fpc->regmap, FTM_FMS, &val);
+	if (val & FTM_FMS_WPEN)
+		regmap_set_bits(fpc->regmap, FTM_MODE, FTM_MODE_WPDIS);
+}
+
+static void ftm_set_write_protection(struct fsl_pwm_chip *fpc)
+{
+	regmap_set_bits(fpc->regmap, FTM_FMS, FTM_FMS_WPEN);
+}
+
+static bool fsl_pwm_periodcfg_are_equal(const struct fsl_pwm_periodcfg *a,
+					const struct fsl_pwm_periodcfg *b)
+{
+	if (a->clk_select != b->clk_select)
+		return false;
+	if (a->clk_ps != b->clk_ps)
+		return false;
+	if (a->mod_period != b->mod_period)
+		return false;
+	return true;
+}
+
+static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	int ret;
+	struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+
+	ret = clk_prepare_enable(fpc->ipg_clk);
+	if (!ret && fpc->soc->has_enable_bits) {
+		mutex_lock(&fpc->lock);
+		regmap_set_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16));
+		mutex_unlock(&fpc->lock);
+	}
+
+	return ret;
+}
+
+static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+
+	if (fpc->soc->has_enable_bits) {
+		mutex_lock(&fpc->lock);
+		regmap_clear_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16));
+		mutex_unlock(&fpc->lock);
+	}
+
+	clk_disable_unprepare(fpc->ipg_clk);
+}
+
+static unsigned int fsl_pwm_ticks_to_ns(struct fsl_pwm_chip *fpc,
+					  unsigned int ticks)
+{
+	unsigned long rate;
+	unsigned long long exval;
+
+	rate = clk_get_rate(fpc->clk[fpc->period.clk_select]);
+	exval = ticks;
+	exval *= 1000000000UL;
+	do_div(exval, rate >> fpc->period.clk_ps);
+	return exval;
+}
+
+static bool fsl_pwm_calculate_period_clk(struct fsl_pwm_chip *fpc,
+					 unsigned int period_ns,
+					 enum fsl_pwm_clk index,
+					 struct fsl_pwm_periodcfg *periodcfg
+					 )
+{
+	unsigned long long c;
+	unsigned int ps;
+
+	c = clk_get_rate(fpc->clk[index]);
+	c = c * period_ns;
+	do_div(c, 1000000000UL);
+
+	if (c == 0)
+		return false;
+
+	for (ps = 0; ps < 8 ; ++ps, c >>= 1) {
+		if (c <= 0x10000) {
+			periodcfg->clk_select = index;
+			periodcfg->clk_ps = ps;
+			periodcfg->mod_period = c - 1;
+			return true;
+		}
+	}
+	return false;
+}
+
+static bool fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
+				     unsigned int period_ns,
+				     struct fsl_pwm_periodcfg *periodcfg)
+{
+	enum fsl_pwm_clk m0, m1;
+	unsigned long fix_rate, ext_rate;
+	bool ret;
+
+	ret = fsl_pwm_calculate_period_clk(fpc, period_ns, FSL_PWM_CLK_SYS,
+					   periodcfg);
+	if (ret)
+		return true;
+
+	fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
+	ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
+
+	if (fix_rate > ext_rate) {
+		m0 = FSL_PWM_CLK_FIX;
+		m1 = FSL_PWM_CLK_EXT;
+	} else {
+		m0 = FSL_PWM_CLK_EXT;
+		m1 = FSL_PWM_CLK_FIX;
+	}
+
+	ret = fsl_pwm_calculate_period_clk(fpc, period_ns, m0, periodcfg);
+	if (ret)
+		return true;
+
+	return fsl_pwm_calculate_period_clk(fpc, period_ns, m1, periodcfg);
+}
+
+static unsigned int fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
+					   unsigned int duty_ns)
+{
+	unsigned long long duty;
+
+	unsigned int period = fpc->period.mod_period + 1;
+	unsigned int period_ns = fsl_pwm_ticks_to_ns(fpc, period);
+
+	duty = (unsigned long long)duty_ns * period;
+	do_div(duty, period_ns);
+
+	return (unsigned int)duty;
+}
+
+static bool fsl_pwm_is_any_pwm_enabled(struct fsl_pwm_chip *fpc,
+				       struct pwm_device *pwm)
+{
+	u32 val;
+
+	regmap_read(fpc->regmap, FTM_OUTMASK, &val);
+	if (~val & 0xFF)
+		return true;
+	else
+		return false;
+}
+
+static bool fsl_pwm_is_other_pwm_enabled(struct fsl_pwm_chip *fpc,
+					 struct pwm_device *pwm)
+{
+	u32 val;
+
+	regmap_read(fpc->regmap, FTM_OUTMASK, &val);
+	if (~(val | BIT(pwm->hwpwm)) & 0xFF)
+		return true;
+	else
+		return false;
+}
+
+static int fsl_pwm_apply_config(struct fsl_pwm_chip *fpc,
+				struct pwm_device *pwm,
+				const struct pwm_state *newstate)
+{
+	unsigned int duty;
+	u32 reg_polarity;
+
+	struct fsl_pwm_periodcfg periodcfg;
+	bool do_write_period = false;
+
+	if (!fsl_pwm_calculate_period(fpc, newstate->period, &periodcfg)) {
+		dev_err(fpc->chip.dev, "failed to calculate new period\n");
+		return -EINVAL;
+	}
+
+	if (!fsl_pwm_is_any_pwm_enabled(fpc, pwm))
+		do_write_period = true;
+	/*
+	 * The Freescale FTM controller supports only a single period for
+	 * all PWM channels, therefore verify if the newly computed period
+	 * is different than the current period being used. In such case
+	 * we allow to change the period only if no other pwm is running.
+	 */
+	else if (!fsl_pwm_periodcfg_are_equal(&fpc->period, &periodcfg)) {
+		if (fsl_pwm_is_other_pwm_enabled(fpc, pwm)) {
+			dev_err(fpc->chip.dev,
+				"Cannot change period for PWM %u, disable other PWMs first\n",
+				pwm->hwpwm);
+			return -EBUSY;
+		}
+		if (fpc->period.clk_select != periodcfg.clk_select) {
+			int ret;
+			enum fsl_pwm_clk oldclk = fpc->period.clk_select;
+			enum fsl_pwm_clk newclk = periodcfg.clk_select;
+
+			ret = clk_prepare_enable(fpc->clk[newclk]);
+			if (ret)
+				return ret;
+			clk_disable_unprepare(fpc->clk[oldclk]);
+		}
+		do_write_period = true;
+	}
+
+	ftm_clear_write_protection(fpc);
+
+	if (do_write_period) {
+		regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
+				   FTM_SC_CLK(periodcfg.clk_select));
+		regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
+				   periodcfg.clk_ps);
+		regmap_write(fpc->regmap, FTM_MOD, periodcfg.mod_period);
+
+		fpc->period = periodcfg;
+	}
+
+	duty = fsl_pwm_calculate_duty(fpc, newstate->duty_cycle);
+
+	regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
+		     FTM_CSC_MSB | FTM_CSC_ELSB);
+	regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
+
+	reg_polarity = 0;
+	if (newstate->polarity == PWM_POLARITY_INVERSED)
+		reg_polarity = BIT(pwm->hwpwm);
+
+	regmap_update_bits(fpc->regmap, FTM_POL, BIT(pwm->hwpwm), reg_polarity);
+
+	ftm_set_write_protection(fpc);
+
+	return 0;
+}
+
+static int fsl_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			 const struct pwm_state *newstate)
+{
+	struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
+	struct pwm_state *oldstate = &pwm->state;
+	int ret = 0;
+
+	/*
+	 * oldstate to newstate : action
+	 *
+	 * disabled to disabled : ignore
+	 * enabled to disabled : disable
+	 * enabled to enabled : update settings
+	 * disabled to enabled : update settings + enable
+	 */
+
+	mutex_lock(&fpc->lock);
+
+	if (!newstate->enabled) {
+		if (oldstate->enabled) {
+			regmap_set_bits(fpc->regmap, FTM_OUTMASK,
+					BIT(pwm->hwpwm));
+			clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
+			clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
+		}
+
+		goto end_mutex;
+	}
+
+	ret = fsl_pwm_apply_config(fpc, pwm, newstate);
+	if (ret)
+		goto end_mutex;
+
+	/* check if need to enable */
+	if (!oldstate->enabled) {
+		ret = clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
+		if (ret)
+			goto end_mutex;
+
+		ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
+		if (ret) {
+			clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
+			goto end_mutex;
+		}
+
+		regmap_clear_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm));
+	}
+
+end_mutex:
+	mutex_unlock(&fpc->lock);
+	return ret;
+}
+
+static const struct pwm_ops fsl_pwm_ops = {
+	.request = fsl_pwm_request,
+	.free = fsl_pwm_free,
+	.apply = fsl_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
+{
+	int ret;
+
+	ret = clk_prepare_enable(fpc->ipg_clk);
+	if (ret)
+		return ret;
+
+	regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
+	regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
+	regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
+
+	clk_disable_unprepare(fpc->ipg_clk);
+
+	return 0;
+}
+
+static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case FTM_FMS:
+	case FTM_MODE:
+	case FTM_CNT:
+		return true;
+	}
+	return false;
+}
+
+static const struct regmap_config fsl_pwm_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+
+	.max_register = FTM_PWMLOAD,
+	.volatile_reg = fsl_pwm_volatile_reg,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static int fsl_pwm_probe(struct platform_device *pdev)
+{
+	struct fsl_pwm_chip *fpc;
+	void __iomem *base;
+	int ret;
+
+	fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
+	if (!fpc)
+		return -ENOMEM;
+
+	mutex_init(&fpc->lock);
+
+	fpc->soc = of_device_get_match_data(&pdev->dev);
+	fpc->chip.dev = &pdev->dev;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "ftm_sys", base,
+						&fsl_pwm_regmap_config);
+	if (IS_ERR(fpc->regmap)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		return PTR_ERR(fpc->regmap);
+	}
+
+	fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
+	if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
+		dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
+		return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
+	}
+
+	fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
+	if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
+		return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
+
+	fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
+	if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
+		return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
+
+	fpc->clk[FSL_PWM_CLK_CNTEN] =
+				devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
+	if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
+		return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
+
+	/*
+	 * ipg_clk is the interface clock for the IP. If not provided, use the
+	 * ftm_sys clock as the default.
+	 */
+	fpc->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(fpc->ipg_clk))
+		fpc->ipg_clk = fpc->clk[FSL_PWM_CLK_SYS];
+
+
+	fpc->chip.ops = &fsl_pwm_ops;
+	fpc->chip.npwm = 8;
+
+	ret = devm_pwmchip_add(&pdev->dev, &fpc->chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, fpc);
+
+	return fsl_pwm_init(fpc);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int fsl_pwm_suspend(struct device *dev)
+{
+	struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
+	int i;
+
+	regcache_cache_only(fpc->regmap, true);
+	regcache_mark_dirty(fpc->regmap);
+
+	for (i = 0; i < fpc->chip.npwm; i++) {
+		struct pwm_device *pwm = &fpc->chip.pwms[i];
+
+		if (!test_bit(PWMF_REQUESTED, &pwm->flags))
+			continue;
+
+		clk_disable_unprepare(fpc->ipg_clk);
+
+		if (!pwm_is_enabled(pwm))
+			continue;
+
+		clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
+		clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
+	}
+
+	return 0;
+}
+
+static int fsl_pwm_resume(struct device *dev)
+{
+	struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
+	int i;
+
+	for (i = 0; i < fpc->chip.npwm; i++) {
+		struct pwm_device *pwm = &fpc->chip.pwms[i];
+
+		if (!test_bit(PWMF_REQUESTED, &pwm->flags))
+			continue;
+
+		clk_prepare_enable(fpc->ipg_clk);
+
+		if (!pwm_is_enabled(pwm))
+			continue;
+
+		clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
+		clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
+	}
+
+	/* restore all registers from cache */
+	regcache_cache_only(fpc->regmap, false);
+	regcache_sync(fpc->regmap);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops fsl_pwm_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(fsl_pwm_suspend, fsl_pwm_resume)
+};
+
+static const struct fsl_ftm_soc vf610_ftm_pwm = {
+	.has_enable_bits = false,
+};
+
+static const struct fsl_ftm_soc imx8qm_ftm_pwm = {
+	.has_enable_bits = true,
+};
+
+static const struct of_device_id fsl_pwm_dt_ids[] = {
+	{ .compatible = "fsl,vf610-ftm-pwm", .data = &vf610_ftm_pwm },
+	{ .compatible = "fsl,imx8qm-ftm-pwm", .data = &imx8qm_ftm_pwm },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
+
+static struct platform_driver fsl_pwm_driver = {
+	.driver = {
+		.name = "fsl-ftm-pwm",
+		.of_match_table = fsl_pwm_dt_ids,
+		.pm = &fsl_pwm_pm_ops,
+	},
+	.probe = fsl_pwm_probe,
+};
+module_platform_driver(fsl_pwm_driver);
+
+MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
+MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
+MODULE_ALIAS("platform:fsl-ftm-pwm");
+MODULE_LICENSE("GPL");