summaryrefslogtreecommitdiffstats
path: root/drivers/pwm/pwm-stm32.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/pwm/pwm-stm32.c')
-rw-r--r--drivers/pwm/pwm-stm32.c710
1 files changed, 710 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
new file mode 100644
index 000000000..bdcdb7f38
--- /dev/null
+++ b/drivers/pwm/pwm-stm32.c
@@ -0,0 +1,710 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2016
+ *
+ * Author: Gerald Baeza <gerald.baeza@st.com>
+ *
+ * Inspired by timer-stm32.c from Maxime Coquelin
+ * pwm-atmel.c from Bo Shen
+ */
+
+#include <linux/bitfield.h>
+#include <linux/mfd/stm32-timers.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#define CCMR_CHANNEL_SHIFT 8
+#define CCMR_CHANNEL_MASK 0xFF
+#define MAX_BREAKINPUT 2
+
+struct stm32_breakinput {
+ u32 index;
+ u32 level;
+ u32 filter;
+};
+
+struct stm32_pwm {
+ struct pwm_chip chip;
+ struct mutex lock; /* protect pwm config/enable */
+ struct clk *clk;
+ struct regmap *regmap;
+ u32 max_arr;
+ bool have_complementary_output;
+ struct stm32_breakinput breakinputs[MAX_BREAKINPUT];
+ unsigned int num_breakinputs;
+ u32 capture[4] ____cacheline_aligned; /* DMA'able buffer */
+};
+
+static inline struct stm32_pwm *to_stm32_pwm_dev(struct pwm_chip *chip)
+{
+ return container_of(chip, struct stm32_pwm, chip);
+}
+
+static u32 active_channels(struct stm32_pwm *dev)
+{
+ u32 ccer;
+
+ regmap_read(dev->regmap, TIM_CCER, &ccer);
+
+ return ccer & TIM_CCER_CCXE;
+}
+
+static int write_ccrx(struct stm32_pwm *dev, int ch, u32 value)
+{
+ switch (ch) {
+ case 0:
+ return regmap_write(dev->regmap, TIM_CCR1, value);
+ case 1:
+ return regmap_write(dev->regmap, TIM_CCR2, value);
+ case 2:
+ return regmap_write(dev->regmap, TIM_CCR3, value);
+ case 3:
+ return regmap_write(dev->regmap, TIM_CCR4, value);
+ }
+ return -EINVAL;
+}
+
+#define TIM_CCER_CC12P (TIM_CCER_CC1P | TIM_CCER_CC2P)
+#define TIM_CCER_CC12E (TIM_CCER_CC1E | TIM_CCER_CC2E)
+#define TIM_CCER_CC34P (TIM_CCER_CC3P | TIM_CCER_CC4P)
+#define TIM_CCER_CC34E (TIM_CCER_CC3E | TIM_CCER_CC4E)
+
+/*
+ * Capture using PWM input mode:
+ * ___ ___
+ * TI[1, 2, 3 or 4]: ........._| |________|
+ * ^0 ^1 ^2
+ * . . .
+ * . . XXXXX
+ * . . XXXXX |
+ * . XXXXX . |
+ * XXXXX . . |
+ * COUNTER: ______XXXXX . . . |_XXX
+ * start^ . . . ^stop
+ * . . . .
+ * v v . v
+ * v
+ * CCR1/CCR3: tx..........t0...........t2
+ * CCR2/CCR4: tx..............t1.........
+ *
+ * DMA burst transfer: | |
+ * v v
+ * DMA buffer: { t0, tx } { t2, t1 }
+ * DMA done: ^
+ *
+ * 0: IC1/3 snapchot on rising edge: counter value -> CCR1/CCR3
+ * + DMA transfer CCR[1/3] & CCR[2/4] values (t0, tx: doesn't care)
+ * 1: IC2/4 snapchot on falling edge: counter value -> CCR2/CCR4
+ * 2: IC1/3 snapchot on rising edge: counter value -> CCR1/CCR3
+ * + DMA transfer CCR[1/3] & CCR[2/4] values (t2, t1)
+ *
+ * DMA done, compute:
+ * - Period = t2 - t0
+ * - Duty cycle = t1 - t0
+ */
+static int stm32_pwm_raw_capture(struct stm32_pwm *priv, struct pwm_device *pwm,
+ unsigned long tmo_ms, u32 *raw_prd,
+ u32 *raw_dty)
+{
+ struct device *parent = priv->chip.dev->parent;
+ enum stm32_timers_dmas dma_id;
+ u32 ccen, ccr;
+ int ret;
+
+ /* Ensure registers have been updated, enable counter and capture */
+ regmap_set_bits(priv->regmap, TIM_EGR, TIM_EGR_UG);
+ regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
+
+ /* Use cc1 or cc3 DMA resp for PWM input channels 1 & 2 or 3 & 4 */
+ dma_id = pwm->hwpwm < 2 ? STM32_TIMERS_DMA_CH1 : STM32_TIMERS_DMA_CH3;
+ ccen = pwm->hwpwm < 2 ? TIM_CCER_CC12E : TIM_CCER_CC34E;
+ ccr = pwm->hwpwm < 2 ? TIM_CCR1 : TIM_CCR3;
+ regmap_set_bits(priv->regmap, TIM_CCER, ccen);
+
+ /*
+ * Timer DMA burst mode. Request 2 registers, 2 bursts, to get both
+ * CCR1 & CCR2 (or CCR3 & CCR4) on each capture event.
+ * We'll get two capture snapchots: { CCR1, CCR2 }, { CCR1, CCR2 }
+ * or { CCR3, CCR4 }, { CCR3, CCR4 }
+ */
+ ret = stm32_timers_dma_burst_read(parent, priv->capture, dma_id, ccr, 2,
+ 2, tmo_ms);
+ if (ret)
+ goto stop;
+
+ /* Period: t2 - t0 (take care of counter overflow) */
+ if (priv->capture[0] <= priv->capture[2])
+ *raw_prd = priv->capture[2] - priv->capture[0];
+ else
+ *raw_prd = priv->max_arr - priv->capture[0] + priv->capture[2];
+
+ /* Duty cycle capture requires at least two capture units */
+ if (pwm->chip->npwm < 2)
+ *raw_dty = 0;
+ else if (priv->capture[0] <= priv->capture[3])
+ *raw_dty = priv->capture[3] - priv->capture[0];
+ else
+ *raw_dty = priv->max_arr - priv->capture[0] + priv->capture[3];
+
+ if (*raw_dty > *raw_prd) {
+ /*
+ * Race beetween PWM input and DMA: it may happen
+ * falling edge triggers new capture on TI2/4 before DMA
+ * had a chance to read CCR2/4. It means capture[1]
+ * contains period + duty_cycle. So, subtract period.
+ */
+ *raw_dty -= *raw_prd;
+ }
+
+stop:
+ regmap_clear_bits(priv->regmap, TIM_CCER, ccen);
+ regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
+
+ return ret;
+}
+
+static int stm32_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_capture *result, unsigned long tmo_ms)
+{
+ struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+ unsigned long long prd, div, dty;
+ unsigned long rate;
+ unsigned int psc = 0, icpsc, scale;
+ u32 raw_prd = 0, raw_dty = 0;
+ int ret = 0;
+
+ mutex_lock(&priv->lock);
+
+ if (active_channels(priv)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ ret = clk_enable(priv->clk);
+ if (ret) {
+ dev_err(priv->chip.dev, "failed to enable counter clock\n");
+ goto unlock;
+ }
+
+ rate = clk_get_rate(priv->clk);
+ if (!rate) {
+ ret = -EINVAL;
+ goto clk_dis;
+ }
+
+ /* prescaler: fit timeout window provided by upper layer */
+ div = (unsigned long long)rate * (unsigned long long)tmo_ms;
+ do_div(div, MSEC_PER_SEC);
+ prd = div;
+ while ((div > priv->max_arr) && (psc < MAX_TIM_PSC)) {
+ psc++;
+ div = prd;
+ do_div(div, psc + 1);
+ }
+ regmap_write(priv->regmap, TIM_ARR, priv->max_arr);
+ regmap_write(priv->regmap, TIM_PSC, psc);
+
+ /* Map TI1 or TI2 PWM input to IC1 & IC2 (or TI3/4 to IC3 & IC4) */
+ regmap_update_bits(priv->regmap,
+ pwm->hwpwm < 2 ? TIM_CCMR1 : TIM_CCMR2,
+ TIM_CCMR_CC1S | TIM_CCMR_CC2S, pwm->hwpwm & 0x1 ?
+ TIM_CCMR_CC1S_TI2 | TIM_CCMR_CC2S_TI2 :
+ TIM_CCMR_CC1S_TI1 | TIM_CCMR_CC2S_TI1);
+
+ /* Capture period on IC1/3 rising edge, duty cycle on IC2/4 falling. */
+ regmap_update_bits(priv->regmap, TIM_CCER, pwm->hwpwm < 2 ?
+ TIM_CCER_CC12P : TIM_CCER_CC34P, pwm->hwpwm < 2 ?
+ TIM_CCER_CC2P : TIM_CCER_CC4P);
+
+ ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
+ if (ret)
+ goto stop;
+
+ /*
+ * Got a capture. Try to improve accuracy at high rates:
+ * - decrease counter clock prescaler, scale up to max rate.
+ * - use input prescaler, capture once every /2 /4 or /8 edges.
+ */
+ if (raw_prd) {
+ u32 max_arr = priv->max_arr - 0x1000; /* arbitrary margin */
+
+ scale = max_arr / min(max_arr, raw_prd);
+ } else {
+ scale = priv->max_arr; /* bellow resolution, use max scale */
+ }
+
+ if (psc && scale > 1) {
+ /* 2nd measure with new scale */
+ psc /= scale;
+ regmap_write(priv->regmap, TIM_PSC, psc);
+ ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd,
+ &raw_dty);
+ if (ret)
+ goto stop;
+ }
+
+ /* Compute intermediate period not to exceed timeout at low rates */
+ prd = (unsigned long long)raw_prd * (psc + 1) * NSEC_PER_SEC;
+ do_div(prd, rate);
+
+ for (icpsc = 0; icpsc < MAX_TIM_ICPSC ; icpsc++) {
+ /* input prescaler: also keep arbitrary margin */
+ if (raw_prd >= (priv->max_arr - 0x1000) >> (icpsc + 1))
+ break;
+ if (prd >= (tmo_ms * NSEC_PER_MSEC) >> (icpsc + 2))
+ break;
+ }
+
+ if (!icpsc)
+ goto done;
+
+ /* Last chance to improve period accuracy, using input prescaler */
+ regmap_update_bits(priv->regmap,
+ pwm->hwpwm < 2 ? TIM_CCMR1 : TIM_CCMR2,
+ TIM_CCMR_IC1PSC | TIM_CCMR_IC2PSC,
+ FIELD_PREP(TIM_CCMR_IC1PSC, icpsc) |
+ FIELD_PREP(TIM_CCMR_IC2PSC, icpsc));
+
+ ret = stm32_pwm_raw_capture(priv, pwm, tmo_ms, &raw_prd, &raw_dty);
+ if (ret)
+ goto stop;
+
+ if (raw_dty >= (raw_prd >> icpsc)) {
+ /*
+ * We may fall here using input prescaler, when input
+ * capture starts on high side (before falling edge).
+ * Example with icpsc to capture on each 4 events:
+ *
+ * start 1st capture 2nd capture
+ * v v v
+ * ___ _____ _____ _____ _____ ____
+ * TI1..4 |__| |__| |__| |__| |__|
+ * v v . . . . . v v
+ * icpsc1/3: . 0 . 1 . 2 . 3 . 0
+ * icpsc2/4: 0 1 2 3 0
+ * v v v v
+ * CCR1/3 ......t0..............................t2
+ * CCR2/4 ..t1..............................t1'...
+ * . . .
+ * Capture0: .<----------------------------->.
+ * Capture1: .<-------------------------->. .
+ * . . .
+ * Period: .<------> . .
+ * Low side: .<>.
+ *
+ * Result:
+ * - Period = Capture0 / icpsc
+ * - Duty = Period - Low side = Period - (Capture0 - Capture1)
+ */
+ raw_dty = (raw_prd >> icpsc) - (raw_prd - raw_dty);
+ }
+
+done:
+ prd = (unsigned long long)raw_prd * (psc + 1) * NSEC_PER_SEC;
+ result->period = DIV_ROUND_UP_ULL(prd, rate << icpsc);
+ dty = (unsigned long long)raw_dty * (psc + 1) * NSEC_PER_SEC;
+ result->duty_cycle = DIV_ROUND_UP_ULL(dty, rate);
+stop:
+ regmap_write(priv->regmap, TIM_CCER, 0);
+ regmap_write(priv->regmap, pwm->hwpwm < 2 ? TIM_CCMR1 : TIM_CCMR2, 0);
+ regmap_write(priv->regmap, TIM_PSC, 0);
+clk_dis:
+ clk_disable(priv->clk);
+unlock:
+ mutex_unlock(&priv->lock);
+
+ return ret;
+}
+
+static int stm32_pwm_config(struct stm32_pwm *priv, int ch,
+ int duty_ns, int period_ns)
+{
+ unsigned long long prd, div, dty;
+ unsigned int prescaler = 0;
+ u32 ccmr, mask, shift;
+
+ /* Period and prescaler values depends on clock rate */
+ div = (unsigned long long)clk_get_rate(priv->clk) * period_ns;
+
+ do_div(div, NSEC_PER_SEC);
+ prd = div;
+
+ while (div > priv->max_arr) {
+ prescaler++;
+ div = prd;
+ do_div(div, prescaler + 1);
+ }
+
+ prd = div;
+
+ if (prescaler > MAX_TIM_PSC)
+ return -EINVAL;
+
+ /*
+ * All channels share the same prescaler and counter so when two
+ * channels are active at the same time we can't change them
+ */
+ if (active_channels(priv) & ~(1 << ch * 4)) {
+ u32 psc, arr;
+
+ regmap_read(priv->regmap, TIM_PSC, &psc);
+ regmap_read(priv->regmap, TIM_ARR, &arr);
+
+ if ((psc != prescaler) || (arr != prd - 1))
+ return -EBUSY;
+ }
+
+ regmap_write(priv->regmap, TIM_PSC, prescaler);
+ regmap_write(priv->regmap, TIM_ARR, prd - 1);
+ regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE);
+
+ /* Calculate the duty cycles */
+ dty = prd * duty_ns;
+ do_div(dty, period_ns);
+
+ write_ccrx(priv, ch, dty);
+
+ /* Configure output mode */
+ shift = (ch & 0x1) * CCMR_CHANNEL_SHIFT;
+ ccmr = (TIM_CCMR_PE | TIM_CCMR_M1) << shift;
+ mask = CCMR_CHANNEL_MASK << shift;
+
+ if (ch < 2)
+ regmap_update_bits(priv->regmap, TIM_CCMR1, mask, ccmr);
+ else
+ regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr);
+
+ regmap_set_bits(priv->regmap, TIM_BDTR, TIM_BDTR_MOE);
+
+ return 0;
+}
+
+static int stm32_pwm_set_polarity(struct stm32_pwm *priv, int ch,
+ enum pwm_polarity polarity)
+{
+ u32 mask;
+
+ mask = TIM_CCER_CC1P << (ch * 4);
+ if (priv->have_complementary_output)
+ mask |= TIM_CCER_CC1NP << (ch * 4);
+
+ regmap_update_bits(priv->regmap, TIM_CCER, mask,
+ polarity == PWM_POLARITY_NORMAL ? 0 : mask);
+
+ return 0;
+}
+
+static int stm32_pwm_enable(struct stm32_pwm *priv, int ch)
+{
+ u32 mask;
+ int ret;
+
+ ret = clk_enable(priv->clk);
+ if (ret)
+ return ret;
+
+ /* Enable channel */
+ mask = TIM_CCER_CC1E << (ch * 4);
+ if (priv->have_complementary_output)
+ mask |= TIM_CCER_CC1NE << (ch * 4);
+
+ regmap_set_bits(priv->regmap, TIM_CCER, mask);
+
+ /* Make sure that registers are updated */
+ regmap_set_bits(priv->regmap, TIM_EGR, TIM_EGR_UG);
+
+ /* Enable controller */
+ regmap_set_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
+
+ return 0;
+}
+
+static void stm32_pwm_disable(struct stm32_pwm *priv, int ch)
+{
+ u32 mask;
+
+ /* Disable channel */
+ mask = TIM_CCER_CC1E << (ch * 4);
+ if (priv->have_complementary_output)
+ mask |= TIM_CCER_CC1NE << (ch * 4);
+
+ regmap_clear_bits(priv->regmap, TIM_CCER, mask);
+
+ /* When all channels are disabled, we can disable the controller */
+ if (!active_channels(priv))
+ regmap_clear_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN);
+
+ clk_disable(priv->clk);
+}
+
+static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ bool enabled;
+ struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+ int ret;
+
+ enabled = pwm->state.enabled;
+
+ if (enabled && !state->enabled) {
+ stm32_pwm_disable(priv, pwm->hwpwm);
+ return 0;
+ }
+
+ if (state->polarity != pwm->state.polarity)
+ stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity);
+
+ ret = stm32_pwm_config(priv, pwm->hwpwm,
+ state->duty_cycle, state->period);
+ if (ret)
+ return ret;
+
+ if (!enabled && state->enabled)
+ ret = stm32_pwm_enable(priv, pwm->hwpwm);
+
+ return ret;
+}
+
+static int stm32_pwm_apply_locked(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+ int ret;
+
+ /* protect common prescaler for all active channels */
+ mutex_lock(&priv->lock);
+ ret = stm32_pwm_apply(chip, pwm, state);
+ mutex_unlock(&priv->lock);
+
+ return ret;
+}
+
+static const struct pwm_ops stm32pwm_ops = {
+ .owner = THIS_MODULE,
+ .apply = stm32_pwm_apply_locked,
+ .capture = IS_ENABLED(CONFIG_DMA_ENGINE) ? stm32_pwm_capture : NULL,
+};
+
+static int stm32_pwm_set_breakinput(struct stm32_pwm *priv,
+ const struct stm32_breakinput *bi)
+{
+ u32 shift = TIM_BDTR_BKF_SHIFT(bi->index);
+ u32 bke = TIM_BDTR_BKE(bi->index);
+ u32 bkp = TIM_BDTR_BKP(bi->index);
+ u32 bkf = TIM_BDTR_BKF(bi->index);
+ u32 mask = bkf | bkp | bke;
+ u32 bdtr;
+
+ bdtr = (bi->filter & TIM_BDTR_BKF_MASK) << shift | bke;
+
+ if (bi->level)
+ bdtr |= bkp;
+
+ regmap_update_bits(priv->regmap, TIM_BDTR, mask, bdtr);
+
+ regmap_read(priv->regmap, TIM_BDTR, &bdtr);
+
+ return (bdtr & bke) ? 0 : -EINVAL;
+}
+
+static int stm32_pwm_apply_breakinputs(struct stm32_pwm *priv)
+{
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < priv->num_breakinputs; i++) {
+ ret = stm32_pwm_set_breakinput(priv, &priv->breakinputs[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int stm32_pwm_probe_breakinputs(struct stm32_pwm *priv,
+ struct device_node *np)
+{
+ int nb, ret, array_size;
+ unsigned int i;
+
+ nb = of_property_count_elems_of_size(np, "st,breakinput",
+ sizeof(struct stm32_breakinput));
+
+ /*
+ * Because "st,breakinput" parameter is optional do not make probe
+ * failed if it doesn't exist.
+ */
+ if (nb <= 0)
+ return 0;
+
+ if (nb > MAX_BREAKINPUT)
+ return -EINVAL;
+
+ priv->num_breakinputs = nb;
+ array_size = nb * sizeof(struct stm32_breakinput) / sizeof(u32);
+ ret = of_property_read_u32_array(np, "st,breakinput",
+ (u32 *)priv->breakinputs, array_size);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < priv->num_breakinputs; i++) {
+ if (priv->breakinputs[i].index > 1 ||
+ priv->breakinputs[i].level > 1 ||
+ priv->breakinputs[i].filter > 15)
+ return -EINVAL;
+ }
+
+ return stm32_pwm_apply_breakinputs(priv);
+}
+
+static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
+{
+ u32 ccer;
+
+ /*
+ * If complementary bit doesn't exist writing 1 will have no
+ * effect so we can detect it.
+ */
+ regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CC1NE);
+ regmap_read(priv->regmap, TIM_CCER, &ccer);
+ regmap_clear_bits(priv->regmap, TIM_CCER, TIM_CCER_CC1NE);
+
+ priv->have_complementary_output = (ccer != 0);
+}
+
+static unsigned int stm32_pwm_detect_channels(struct stm32_pwm *priv,
+ unsigned int *num_enabled)
+{
+ u32 ccer, ccer_backup;
+
+ /*
+ * If channels enable bits don't exist writing 1 will have no
+ * effect so we can detect and count them.
+ */
+ regmap_read(priv->regmap, TIM_CCER, &ccer_backup);
+ regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE);
+ regmap_read(priv->regmap, TIM_CCER, &ccer);
+ regmap_write(priv->regmap, TIM_CCER, ccer_backup);
+
+ *num_enabled = hweight32(ccer_backup & TIM_CCER_CCXE);
+
+ return hweight32(ccer & TIM_CCER_CCXE);
+}
+
+static int stm32_pwm_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent);
+ struct stm32_pwm *priv;
+ unsigned int num_enabled;
+ unsigned int i;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mutex_init(&priv->lock);
+ priv->regmap = ddata->regmap;
+ priv->clk = ddata->clk;
+ priv->max_arr = ddata->max_arr;
+
+ if (!priv->regmap || !priv->clk)
+ return -EINVAL;
+
+ ret = stm32_pwm_probe_breakinputs(priv, np);
+ if (ret)
+ return ret;
+
+ stm32_pwm_detect_complementary(priv);
+
+ priv->chip.dev = dev;
+ priv->chip.ops = &stm32pwm_ops;
+ priv->chip.npwm = stm32_pwm_detect_channels(priv, &num_enabled);
+
+ /* Initialize clock refcount to number of enabled PWM channels. */
+ for (i = 0; i < num_enabled; i++)
+ clk_enable(priv->clk);
+
+ ret = pwmchip_add(&priv->chip);
+ if (ret < 0)
+ return ret;
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static int stm32_pwm_remove(struct platform_device *pdev)
+{
+ struct stm32_pwm *priv = platform_get_drvdata(pdev);
+ unsigned int i;
+
+ for (i = 0; i < priv->chip.npwm; i++)
+ pwm_disable(&priv->chip.pwms[i]);
+
+ pwmchip_remove(&priv->chip);
+
+ return 0;
+}
+
+static int __maybe_unused stm32_pwm_suspend(struct device *dev)
+{
+ struct stm32_pwm *priv = dev_get_drvdata(dev);
+ unsigned int i;
+ u32 ccer, mask;
+
+ /* Look for active channels */
+ ccer = active_channels(priv);
+
+ for (i = 0; i < priv->chip.npwm; i++) {
+ mask = TIM_CCER_CC1E << (i * 4);
+ if (ccer & mask) {
+ dev_err(dev, "PWM %u still in use by consumer %s\n",
+ i, priv->chip.pwms[i].label);
+ return -EBUSY;
+ }
+ }
+
+ return pinctrl_pm_select_sleep_state(dev);
+}
+
+static int __maybe_unused stm32_pwm_resume(struct device *dev)
+{
+ struct stm32_pwm *priv = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pinctrl_pm_select_default_state(dev);
+ if (ret)
+ return ret;
+
+ /* restore breakinput registers that may have been lost in low power */
+ return stm32_pwm_apply_breakinputs(priv);
+}
+
+static SIMPLE_DEV_PM_OPS(stm32_pwm_pm_ops, stm32_pwm_suspend, stm32_pwm_resume);
+
+static const struct of_device_id stm32_pwm_of_match[] = {
+ { .compatible = "st,stm32-pwm", },
+ { /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, stm32_pwm_of_match);
+
+static struct platform_driver stm32_pwm_driver = {
+ .probe = stm32_pwm_probe,
+ .remove = stm32_pwm_remove,
+ .driver = {
+ .name = "stm32-pwm",
+ .of_match_table = stm32_pwm_of_match,
+ .pm = &stm32_pwm_pm_ops,
+ },
+};
+module_platform_driver(stm32_pwm_driver);
+
+MODULE_ALIAS("platform:stm32-pwm");
+MODULE_DESCRIPTION("STMicroelectronics STM32 PWM driver");
+MODULE_LICENSE("GPL v2");