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path: root/drivers/pwm/pwm-fsl-ftm.c
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-rw-r--r--drivers/pwm/pwm-fsl-ftm.c549
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");