The PWM period will be set when calling pwm_config. Remove this useless call to pwm_set_period(), which might mess up with the internal PWM state.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com Acked-by: Lee Jones lee.jones@linaro.org --- drivers/video/backlight/pwm_bl.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 64f9e1b..a33a290 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -313,10 +313,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) * via the PWM lookup table. */ pb->period = pwm_get_period(pb->pwm); - if (!pb->period && (data->pwm_period_ns > 0)) { + if (!pb->period && (data->pwm_period_ns > 0)) pb->period = data->pwm_period_ns; - pwm_set_period(pb->pwm, data->pwm_period_ns); - }

pb->lth_brightness = data->lth_brightness * (pb->period / pb->scale);

PWM devices are not protected against concurrent accesses. The lock in pwm_device might let PWM users think it is, but it's actually only protecting the enabled state.

Removing this lock should be fine as long as all PWM users are aware that accesses to the PWM device have to be serialized, which seems to be the case for all of them except the sysfs interface. Patch the sysfs code by adding a lock to the pwm_export struct and making sure it's taken for all accesses to the exported PWM device.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/core.c | 19 ++++-------------- drivers/pwm/sysfs.c | 57 ++++++++++++++++++++++++++++++++++++++++++----------- include/linux/pwm.h | 2 -- 3 files changed, 50 insertions(+), 28 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 7831bc6..7c330ff 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -269,7 +269,6 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->pwm = chip->base + i; pwm->hwpwm = i; pwm->polarity = polarity; - mutex_init(&pwm->lock);

radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } @@ -474,22 +473,16 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (!pwm->chip->ops->set_polarity) return -ENOSYS;

- mutex_lock(&pwm->lock); - - if (pwm_is_enabled(pwm)) { - err = -EBUSY; - goto unlock; - } + if (pwm_is_enabled(pwm)) + return -EBUSY;

err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); if (err) - goto unlock; + return err;

pwm->polarity = polarity;

-unlock: - mutex_unlock(&pwm->lock); - return err; + return 0; } EXPORT_SYMBOL_GPL(pwm_set_polarity);

@@ -506,16 +499,12 @@ int pwm_enable(struct pwm_device *pwm) if (!pwm) return -EINVAL;

- mutex_lock(&pwm->lock); - if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) { err = pwm->chip->ops->enable(pwm->chip, pwm); if (err) clear_bit(PWMF_ENABLED, &pwm->flags); }

- mutex_unlock(&pwm->lock); - return err; } EXPORT_SYMBOL_GPL(pwm_enable); diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 9c90886..ab28c89 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -26,6 +26,7 @@ struct pwm_export { struct device child; struct pwm_device *pwm; + struct mutex lock; };

static struct pwm_export *child_to_pwm_export(struct device *child) @@ -44,16 +45,23 @@ static ssize_t period_show(struct device *child, struct device_attribute *attr, char *buf) { - const struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + const struct pwm_device *pwm = export->pwm; + unsigned int period; + + mutex_lock(&export->lock); + period = pwm_get_period(pwm); + mutex_unlock(&export->lock);

- return sprintf(buf, "%u\n", pwm_get_period(pwm)); + return sprintf(buf, "%u\n", period); }

static ssize_t period_store(struct device *child, struct device_attribute *attr, const char *buf, size_t size) { - struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + struct pwm_device *pwm = export->pwm; unsigned int val; int ret;

@@ -61,7 +69,9 @@ static ssize_t period_store(struct device *child, if (ret) return ret;

+ mutex_lock(&export->lock); ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val); + mutex_unlock(&export->lock);

return ret ? : size; } @@ -70,16 +80,23 @@ static ssize_t duty_cycle_show(struct device *child, struct device_attribute *attr, char *buf) { - const struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + const struct pwm_device *pwm = export->pwm; + unsigned int duty; + + mutex_lock(&export->lock); + duty = pwm_get_duty_cycle(pwm); + mutex_unlock(&export->lock);

- return sprintf(buf, "%u\n", pwm_get_duty_cycle(pwm)); + return sprintf(buf, "%u\n", duty); }

static ssize_t duty_cycle_store(struct device *child, struct device_attribute *attr, const char *buf, size_t size) { - struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + struct pwm_device *pwm = export->pwm; unsigned int val; int ret;

@@ -87,7 +104,9 @@ static ssize_t duty_cycle_store(struct device *child, if (ret) return ret;

+ mutex_lock(&export->lock); ret = pwm_config(pwm, val, pwm_get_period(pwm)); + mutex_unlock(&export->lock);

return ret ? : size; } @@ -96,22 +115,30 @@ static ssize_t enable_show(struct device *child, struct device_attribute *attr, char *buf) { - const struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + const struct pwm_device *pwm = export->pwm; + bool enabled; + + mutex_lock(&export->lock); + enabled = pwm_is_enabled(pwm); + mutex_unlock(&export->lock);

- return sprintf(buf, "%d\n", pwm_is_enabled(pwm)); + return sprintf(buf, "%d\n", enabled); }

static ssize_t enable_store(struct device *child, struct device_attribute *attr, const char *buf, size_t size) { - struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + struct pwm_device *pwm = export->pwm; int val, ret;

ret = kstrtoint(buf, 0, &val); if (ret) return ret;

+ mutex_lock(&export->lock); switch (val) { case 0: pwm_disable(pwm); @@ -123,6 +150,7 @@ static ssize_t enable_store(struct device *child, ret = -EINVAL; break; } + mutex_unlock(&export->lock);

return ret ? : size; } @@ -131,9 +159,11 @@ static ssize_t polarity_show(struct device *child, struct device_attribute *attr, char *buf) { - const struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + const struct pwm_device *pwm = export->pwm; const char *polarity = "unknown";

+ mutex_lock(&export->lock); switch (pwm_get_polarity(pwm)) { case PWM_POLARITY_NORMAL: polarity = "normal"; @@ -143,6 +173,7 @@ static ssize_t polarity_show(struct device *child, polarity = "inversed"; break; } + mutex_unlock(&export->lock);

return sprintf(buf, "%s\n", polarity); } @@ -151,7 +182,8 @@ static ssize_t polarity_store(struct device *child, struct device_attribute *attr, const char *buf, size_t size) { - struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_export *export = child_to_pwm_export(child); + struct pwm_device *pwm = export->pwm; enum pwm_polarity polarity; int ret;

@@ -162,7 +194,9 @@ static ssize_t polarity_store(struct device *child, else return -EINVAL;

+ mutex_lock(&export->lock); ret = pwm_set_polarity(pwm, polarity); + mutex_unlock(&export->lock);

return ret ? : size; } @@ -203,6 +237,7 @@ static int pwm_export_child(struct device *parent, struct pwm_device *pwm) }

export->pwm = pwm; + mutex_init(&export->lock);

export->child.release = pwm_export_release; export->child.parent = parent; diff --git a/include/linux/pwm.h b/include/linux/pwm.h index cfc3ed4..6555f01 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -88,7 +88,6 @@ enum { * @pwm: global index of the PWM device * @chip: PWM chip providing this PWM device * @chip_data: chip-private data associated with the PWM device - * @lock: used to serialize accesses to the PWM device where necessary * @period: period of the PWM signal (in nanoseconds) * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) * @polarity: polarity of the PWM signal @@ -100,7 +99,6 @@ struct pwm_device { unsigned int pwm; struct pwm_chip *chip; void *chip_data; - struct mutex lock;

unsigned int period; unsigned int duty_cycle;

The PWM framework has clarified the concept of reference PWM config (the platform dependent config retrieved from the DT or the PWM lookup table) and real PWM state.

Use pwm_get_args() when the PWM user wants to retrieve this reference config and not the current state.

This is part of the rework allowing the PWM framework to support hardware readout and expose real PWM state even when the PWM has just been requested (before the user calls pwm_config/enable/disable()).

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/clk/clk-pwm.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c index 8830458..ebcd738 100644 --- a/drivers/clk/clk-pwm.c +++ b/drivers/clk/clk-pwm.c @@ -56,6 +56,7 @@ static const struct clk_ops clk_pwm_ops = { static int clk_pwm_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; + struct pwm_args pargs = { }; struct clk_init_data init; struct clk_pwm *clk_pwm; struct pwm_device *pwm; @@ -71,22 +72,23 @@ static int clk_pwm_probe(struct platform_device *pdev) if (IS_ERR(pwm)) return PTR_ERR(pwm);

- if (!pwm->period) { + pwm_get_args(pwm, &pargs); + if (!pargs.period) { dev_err(&pdev->dev, "invalid PWM period\n"); return -EINVAL; }

if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate)) - clk_pwm->fixed_rate = NSEC_PER_SEC / pwm->period; + clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;

- if (pwm->period != NSEC_PER_SEC / clk_pwm->fixed_rate && - pwm->period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) { + if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate && + pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) { dev_err(&pdev->dev, "clock-frequency does not match PWM period\n"); return -EINVAL; }

- ret = pwm_config(pwm, (pwm->period + 1) >> 1, pwm->period); + ret = pwm_config(pwm, (pargs.period + 1) >> 1, pargs.period); if (ret < 0) return ret;

The PWM framework has clarified the concept of reference PWM config (the platform dependent config retrieved from the DT or the PWM lookup table) and real PWM state.

Use pwm_get_args() when the PWM user wants to retrieve this reference config and not the current state.

This is part of the rework allowing the PWM framework to support hardware readout and expose real PWM state even when the PWM has just been requested (before the user calls pwm_config/enable/disable()).

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/hwmon/pwm-fan.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 3e23003..82c5656 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -40,15 +40,18 @@ struct pwm_fan_ctx {

static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { + struct pwm_args pargs = { }; unsigned long duty; int ret = 0;

+ pwm_get_args(ctx->pwm, &pargs); + mutex_lock(&ctx->lock); if (ctx->pwm_value == pwm) goto exit_set_pwm_err;

- duty = DIV_ROUND_UP(pwm * (ctx->pwm->period - 1), MAX_PWM); - ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); + duty = DIV_ROUND_UP(pwm * (pargs.period - 1), MAX_PWM); + ret = pwm_config(ctx->pwm, duty, pargs.period); if (ret) goto exit_set_pwm_err;

@@ -214,6 +217,7 @@ static int pwm_fan_of_get_cooling_data(struct device *dev, static int pwm_fan_probe(struct platform_device *pdev) { struct thermal_cooling_device *cdev; + struct pwm_args pargs = { }; struct pwm_fan_ctx *ctx; struct device *hwmon; int duty_cycle; @@ -234,10 +238,11 @@ static int pwm_fan_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ctx);

/* Set duty cycle to maximum allowed */ - duty_cycle = ctx->pwm->period - 1; + pwm_get_args(ctx->pwm, &pargs); + duty_cycle = pargs.period - 1; ctx->pwm_value = MAX_PWM;

- ret = pwm_config(ctx->pwm, duty_cycle, ctx->pwm->period); + ret = pwm_config(ctx->pwm, duty_cycle, pargs.period); if (ret) { dev_err(&pdev->dev, "Failed to configure PWM\n"); return ret; @@ -303,14 +308,16 @@ static int pwm_fan_suspend(struct device *dev) static int pwm_fan_resume(struct device *dev) { struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); + struct pwm_args pargs = { }; unsigned long duty; int ret;

if (ctx->pwm_value == 0) return 0;

- duty = DIV_ROUND_UP(ctx->pwm_value * (ctx->pwm->period - 1), MAX_PWM); - ret = pwm_config(ctx->pwm, duty, ctx->pwm->period); + pwm_get_args(ctx->pwm, &pargs); + duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM); + ret = pwm_config(ctx->pwm, duty, pargs.period); if (ret) return ret; return pwm_enable(ctx->pwm);

The PWM framework has clarified the concept of reference PWM config (the platform dependent config retrieved from the DT or the PWM lookup table) and real PWM state.

Use pwm_get_args() when the PWM user wants to retrieve this reference config and not the current state.

This is part of the rework allowing the PWM framework to support hardware readout and expose real PWM state even when the PWM has just been requested (before the user calls pwm_config/enable/disable()).

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/input/misc/max77693-haptic.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c index 6d96bff..cf6aac0 100644 --- a/drivers/input/misc/max77693-haptic.c +++ b/drivers/input/misc/max77693-haptic.c @@ -70,10 +70,13 @@ struct max77693_haptic {

static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic) { - int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2; + struct pwm_args pargs = { }; + int delta; int error;

- error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period); + pwm_get_args(haptic->pwm_dev, &pargs); + delta = (pargs.period + haptic->pwm_duty) / 2; + error = pwm_config(haptic->pwm_dev, delta, pargs.period); if (error) { dev_err(haptic->dev, "failed to configure pwm: %d\n", error); return error; @@ -234,6 +237,7 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data, struct ff_effect *effect) { struct max77693_haptic *haptic = input_get_drvdata(dev); + struct pwm_args pargs = { }; u64 period_mag_multi;

haptic->magnitude = effect->u.rumble.strong_magnitude; @@ -245,7 +249,8 @@ static int max77693_haptic_play_effect(struct input_dev *dev, void *data, * The formula to convert magnitude to pwm_duty as follows: * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF) */ - period_mag_multi = (u64)haptic->pwm_dev->period * haptic->magnitude; + pwm_get_args(haptic->pwm_dev, &pargs); + period_mag_multi = (u64)pargs.period * haptic->magnitude; haptic->pwm_duty = (unsigned int)(period_mag_multi >> MAX_MAGNITUDE_SHIFT);

The PWM framework has clarified the concept of reference PWM config (the platform dependent config retrieved from the DT or the PWM lookup table) and real PWM state.

Use pwm_get_args() when the PWM user wants to retrieve this reference config and not the current state.

This is part of the rework allowing the PWM framework to support hardware readout and expose real PWM state even when the PWM has just been requested (before the user calls pwm_config/enable/disable()).

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/regulator/pwm-regulator.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 4689d62..9154c47 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -59,16 +59,16 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, unsigned selector) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); - unsigned int pwm_reg_period; + struct pwm_args pargs = { }; int dutycycle; int ret;

- pwm_reg_period = pwm_get_period(drvdata->pwm); + pwm_get_args(drvdata->pwm, &pargs);

- dutycycle = (pwm_reg_period * + dutycycle = (pargs.period * drvdata->duty_cycle_table[selector].dutycycle) / 100;

- ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period); + ret = pwm_config(drvdata->pwm, dutycycle, pargs.period); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM\n"); return ret; @@ -138,13 +138,15 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev, { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); unsigned int ramp_delay = rdev->constraints->ramp_delay; - unsigned int period = pwm_get_period(drvdata->pwm); + struct pwm_args pargs = { }; int duty_cycle; int ret;

+ pwm_get_args(drvdata->pwm, &pargs); duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV);

- ret = pwm_config(drvdata->pwm, (period / 100) * duty_cycle, period); + ret = pwm_config(drvdata->pwm, (pargs.period / 100) * duty_cycle, + pargs.period); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM\n"); return ret;

The PWM framework has clarified the concept of reference PWM config (the platform dependent config retrieved from the DT or the PWM lookup table) and real PWM state.

Use pwm_get_args() when the PWM user wants to retrieve this reference config and not the current state.

This is part of the rework allowing the PWM framework to support hardware readout and expose real PWM state even when the PWM has just been requested (before the user calls pwm_config/enable/disable()).

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/video/backlight/pwm_bl.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index a33a290..2479c11 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -201,6 +201,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) struct device_node *node = pdev->dev.of_node; struct pwm_bl_data *pb; int initial_blank = FB_BLANK_UNBLANK; + struct pwm_args pargs = { }; int ret;

if (!data) { @@ -312,7 +313,8 @@ static int pwm_backlight_probe(struct platform_device *pdev) * set the period from platform data if it has not already been set * via the PWM lookup table. */ - pb->period = pwm_get_period(pb->pwm); + pwm_get_args(pb->pwm, &pargs); + pb->period = pargs.period; if (!pb->period && (data->pwm_period_ns > 0)) pb->period = data->pwm_period_ns;

The PWM state, represented by its period, duty_cycle and polarity, is currently directly stored in the PWM device. Declare a pwm_state structure embedding those field so that we can later use this struct to atomically update all the PWM parameters at once.

All pwm_get_xxx() helpers are now implemented as wrappers around pwm_get_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/core.c | 8 ++++---- include/linux/pwm.h | 54 +++++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 46 insertions(+), 16 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 6433059..f3f91e7 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -268,7 +268,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->chip = chip; pwm->pwm = chip->base + i; pwm->hwpwm = i; - pwm->polarity = polarity; + pwm->state.polarity = polarity;

radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } @@ -446,8 +446,8 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) if (err) return err;

- pwm->duty_cycle = duty_ns; - pwm->period = period_ns; + pwm->state.duty_cycle = duty_ns; + pwm->state.period = period_ns;

return 0; } @@ -480,7 +480,7 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (err) return err;

- pwm->polarity = polarity; + pwm->state.polarity = polarity;

return 0; } diff --git a/include/linux/pwm.h b/include/linux/pwm.h index ed65354..f0f0f37 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -97,6 +97,18 @@ enum { PWMF_EXPORTED = 1 << 2, };

+/* + * struct pwm_state - state of a PWM channel + * @period: PWM period (in nanoseconds) + * @duty_cycle: PWM duty cycle (in nanoseconds) + * @polarity: PWM polarity + */ +struct pwm_state { + unsigned int period; + unsigned int duty_cycle; + enum pwm_polarity polarity; +}; + /** * struct pwm_device - PWM channel object * @label: name of the PWM device @@ -105,10 +117,8 @@ enum { * @pwm: global index of the PWM device * @chip: PWM chip providing this PWM device * @chip_data: chip-private data associated with the PWM device - * @period: period of the PWM signal (in nanoseconds) - * @duty_cycle: duty cycle of the PWM signal (in nanoseconds) - * @polarity: polarity of the PWM signal * @args: PWM arguments + * @state: curent PWM channel state */ struct pwm_device { const char *label; @@ -118,13 +128,21 @@ struct pwm_device { struct pwm_chip *chip; void *chip_data;

- unsigned int period; - unsigned int duty_cycle; - enum pwm_polarity polarity; - struct pwm_args args; + struct pwm_state state; };

+/** + * pwm_get_state() - retrieve the current PWM state + * @pwm: PWM device + * @state: state to fill with the current PWM state + */ +static inline void pwm_get_state(const struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->state; +} + static inline bool pwm_is_enabled(const struct pwm_device *pwm) { return test_bit(PWMF_ENABLED, &pwm->flags); @@ -133,23 +151,31 @@ static inline bool pwm_is_enabled(const struct pwm_device *pwm) static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period) { if (pwm) - pwm->period = period; + pwm->state.period = period; }

static inline unsigned int pwm_get_period(const struct pwm_device *pwm) { - return pwm ? pwm->period : 0; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate); + + return pstate.period; }

static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty) { if (pwm) - pwm->duty_cycle = duty; + pwm->state.duty_cycle = duty; }

static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm) { - return pwm ? pwm->duty_cycle : 0; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate); + + return pstate.duty_cycle; }

/* @@ -159,7 +185,11 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);

static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) { - return pwm ? pwm->polarity : PWM_POLARITY_NORMAL; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate); + + return pstate.polarity; }

static inline void pwm_get_args(const struct pwm_device *pwm,

Add a ->get_state() function to the pwm_ops struct to let PWM drivers initialize the PWM state attached to a PWM device.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/core.c | 3 +++ include/linux/pwm.h | 5 +++++ 2 files changed, 8 insertions(+)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index c240b54..a909c64 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -270,6 +270,9 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->hwpwm = i; pwm->state.polarity = polarity;

+ if (chip->ops->get_state) + chip->ops->get_state(chip, pwm, &pwm->state); + radix_tree_insert(&pwm_tree, pwm->pwm, pwm); }

diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 55bf463..ceedcf8 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -211,6 +211,9 @@ static inline void pwm_get_args(const struct pwm_device *pwm, * @set_polarity: configure the polarity of this PWM * @enable: enable PWM output toggling * @disable: disable PWM output toggling + * @get_state: get the current PWM state. This function is only + * called once per PWM device when the PWM chip is + * registered. * @dbg_show: optional routine to show contents in debugfs * @owner: helps prevent removal of modules exporting active PWMs */ @@ -223,6 +226,8 @@ struct pwm_ops { enum pwm_polarity polarity); int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm); void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); + void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *pstate); #ifdef CONFIG_DEBUG_FS void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s); #endif

Replace legacy pwm_get/set_xxx() and pwm_config/enable/disable() calls by pwm_get/apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/core.c | 5 ++++- drivers/pwm/sysfs.c | 61 +++++++++++++++++++++++++++++++---------------------- 2 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 62e6b3c..c2b1569 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -882,13 +882,16 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)

for (i = 0; i < chip->npwm; i++) { struct pwm_device *pwm = &chip->pwms[i]; + struct pwm_state pstate; + + pwm_get_state(pwm, &pstate);

seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label);

if (test_bit(PWMF_REQUESTED, &pwm->flags)) seq_puts(s, " requested");

- if (pwm_is_enabled(pwm)) + if (pstate.enabled) seq_puts(s, " enabled");

seq_puts(s, "\n"); diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index ab28c89..7ec1747 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -47,13 +47,13 @@ static ssize_t period_show(struct device *child, { struct pwm_export *export = child_to_pwm_export(child); const struct pwm_device *pwm = export->pwm; - unsigned int period; + struct pwm_state pstate;

mutex_lock(&export->lock); - period = pwm_get_period(pwm); + pwm_get_state(pwm, &pstate); mutex_unlock(&export->lock);

- return sprintf(buf, "%u\n", period); + return sprintf(buf, "%u\n", pstate.period); }

static ssize_t period_store(struct device *child, @@ -62,6 +62,7 @@ static ssize_t period_store(struct device *child, { struct pwm_export *export = child_to_pwm_export(child); struct pwm_device *pwm = export->pwm; + struct pwm_state pstate; unsigned int val; int ret;

@@ -70,7 +71,9 @@ static ssize_t period_store(struct device *child, return ret;

mutex_lock(&export->lock); - ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val); + pwm_get_state(pwm, &pstate); + pstate.period = val; + ret = pwm_apply_state(pwm, &pstate); mutex_unlock(&export->lock);

return ret ? : size; @@ -82,13 +85,13 @@ static ssize_t duty_cycle_show(struct device *child, { struct pwm_export *export = child_to_pwm_export(child); const struct pwm_device *pwm = export->pwm; - unsigned int duty; + struct pwm_state pstate;

mutex_lock(&export->lock); - duty = pwm_get_duty_cycle(pwm); + pwm_get_state(pwm, &pstate); mutex_unlock(&export->lock);

- return sprintf(buf, "%u\n", duty); + return sprintf(buf, "%u\n", pstate.duty_cycle); }

static ssize_t duty_cycle_store(struct device *child, @@ -97,6 +100,7 @@ static ssize_t duty_cycle_store(struct device *child, { struct pwm_export *export = child_to_pwm_export(child); struct pwm_device *pwm = export->pwm; + struct pwm_state pstate; unsigned int val; int ret;

@@ -105,7 +109,9 @@ static ssize_t duty_cycle_store(struct device *child, return ret;

mutex_lock(&export->lock); - ret = pwm_config(pwm, val, pwm_get_period(pwm)); + pwm_get_state(pwm, &pstate); + pstate.duty_cycle = val; + ret = pwm_apply_state(pwm, &pstate); mutex_unlock(&export->lock);

return ret ? : size; @@ -117,13 +123,13 @@ static ssize_t enable_show(struct device *child, { struct pwm_export *export = child_to_pwm_export(child); const struct pwm_device *pwm = export->pwm; - bool enabled; + struct pwm_state pstate;

mutex_lock(&export->lock); - enabled = pwm_is_enabled(pwm); + pwm_get_state(pwm, &pstate); mutex_unlock(&export->lock);

- return sprintf(buf, "%d\n", enabled); + return sprintf(buf, "%d\n", pstate.enabled); }

static ssize_t enable_store(struct device *child, @@ -132,24 +138,20 @@ static ssize_t enable_store(struct device *child, { struct pwm_export *export = child_to_pwm_export(child); struct pwm_device *pwm = export->pwm; + struct pwm_state pstate; int val, ret;

ret = kstrtoint(buf, 0, &val); if (ret) return ret;

+ if (val != 0 && val != 1) + return -EINVAL; + mutex_lock(&export->lock); - switch (val) { - case 0: - pwm_disable(pwm); - break; - case 1: - ret = pwm_enable(pwm); - break; - default: - ret = -EINVAL; - break; - } + pwm_get_state(pwm, &pstate); + pstate.enabled = val; + ret = pwm_apply_state(pwm, &pstate); mutex_unlock(&export->lock);

return ret ? : size; @@ -162,9 +164,13 @@ static ssize_t polarity_show(struct device *child, struct pwm_export *export = child_to_pwm_export(child); const struct pwm_device *pwm = export->pwm; const char *polarity = "unknown"; + struct pwm_state pstate;

mutex_lock(&export->lock); - switch (pwm_get_polarity(pwm)) { + pwm_get_state(pwm, &pstate); + mutex_unlock(&export->lock); + + switch (pstate.polarity) { case PWM_POLARITY_NORMAL: polarity = "normal"; break; @@ -173,7 +179,6 @@ static ssize_t polarity_show(struct device *child, polarity = "inversed"; break; } - mutex_unlock(&export->lock);

return sprintf(buf, "%s\n", polarity); } @@ -185,6 +190,7 @@ static ssize_t polarity_store(struct device *child, struct pwm_export *export = child_to_pwm_export(child); struct pwm_device *pwm = export->pwm; enum pwm_polarity polarity; + struct pwm_state pstate; int ret;

if (sysfs_streq(buf, "normal")) @@ -195,7 +201,12 @@ static ssize_t polarity_store(struct device *child, return -EINVAL;

mutex_lock(&export->lock); - ret = pwm_set_polarity(pwm, polarity); + pwm_get_state(pwm, &pstate); + pstate.polarity = polarity; + if (pstate.enabled) + ret = -EBUSY; + else + ret = pwm_apply_state(pwm, &pstate); mutex_unlock(&export->lock);

return ret ? : size;

Implement the ->get_state() function to expose initial state.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/pwm-rockchip.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+)

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index 7d9cc90..6a1087c 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -51,6 +51,8 @@ struct rockchip_pwm_data {

void (*set_enable)(struct pwm_chip *chip, struct pwm_device *pwm, bool enable); + void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *pstate); };

static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c) @@ -75,6 +77,19 @@ static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, writel_relaxed(val, pc->base + pc->data->regs.ctrl); }

+static void rockchip_pwm_get_state_v1(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *pstate) +{ + struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN; + u32 val; + + val = readl(pc->base + pc->data->regs.ctrl); + if ((val & enable_conf) == enable_conf) + pstate->enabled = true; +} + static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, struct pwm_device *pwm, bool enable) { @@ -98,6 +113,55 @@ static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, writel_relaxed(val, pc->base + pc->data->regs.ctrl); }

+static void rockchip_pwm_get_state_v2(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *pstate) +{ + struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | + PWM_CONTINUOUS; + u32 val; + + val = readl(pc->base + pc->data->regs.ctrl); + if ((val & enable_conf) != enable_conf) + return; + + pstate->enabled = true; + + if (!(val & PWM_DUTY_POSITIVE)) + pstate->polarity = PWM_POLARITY_INVERSED; +} + +static void rockchip_pwm_get_state(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *pstate) +{ + struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + unsigned long clk_rate; + u64 tmp; + int ret; + + ret = clk_enable(pc->clk); + if (ret) + return; + + clk_rate = clk_get_rate(pc->clk); + + tmp = readl(pc->base + pc->data->regs.period); + tmp *= pc->data->prescaler * NSEC_PER_SEC; + do_div(tmp, clk_rate); + pstate->period = tmp; + + tmp = readl(pc->base + pc->data->regs.duty); + tmp *= pc->data->prescaler * NSEC_PER_SEC; + do_div(tmp, clk_rate); + pstate->duty_cycle = tmp; + + pc->data->get_state(chip, pwm, pstate); + + clk_disable(pc->clk); +} + static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { @@ -171,6 +235,7 @@ static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) }

static const struct pwm_ops rockchip_pwm_ops_v1 = { + .get_state = rockchip_pwm_get_state, .config = rockchip_pwm_config, .enable = rockchip_pwm_enable, .disable = rockchip_pwm_disable, @@ -178,6 +243,7 @@ static const struct pwm_ops rockchip_pwm_ops_v1 = { };

static const struct pwm_ops rockchip_pwm_ops_v2 = { + .get_state = rockchip_pwm_get_state, .config = rockchip_pwm_config, .set_polarity = rockchip_pwm_set_polarity, .enable = rockchip_pwm_enable, @@ -195,6 +261,7 @@ static const struct rockchip_pwm_data pwm_data_v1 = { .prescaler = 2, .ops = &rockchip_pwm_ops_v1, .set_enable = rockchip_pwm_set_enable_v1, + .get_state = rockchip_pwm_get_state_v1, };

static const struct rockchip_pwm_data pwm_data_v2 = { @@ -207,6 +274,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = { .prescaler = 1, .ops = &rockchip_pwm_ops_v2, .set_enable = rockchip_pwm_set_enable_v2, + .get_state = rockchip_pwm_get_state_v2, };

static const struct rockchip_pwm_data pwm_data_vop = { @@ -219,6 +287,7 @@ static const struct rockchip_pwm_data pwm_data_vop = { .prescaler = 1, .ops = &rockchip_pwm_ops_v2, .set_enable = rockchip_pwm_set_enable_v2, + .get_state = rockchip_pwm_get_state_v2, };

static const struct of_device_id rockchip_pwm_dt_ids[] = {

Implement the ->apply() function to add support for atomic update.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com Tested-by: Heiko Stuebner heiko@sntech.de --- drivers/pwm/pwm-rockchip.c | 63 ++++++++++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 24 deletions(-)

diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index 5c7e79c..ed27740 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -50,7 +50,8 @@ struct rockchip_pwm_data { const struct pwm_ops *ops;

void (*set_enable)(struct pwm_chip *chip, - struct pwm_device *pwm, bool enable); + struct pwm_device *pwm, bool enable, + enum pwm_polarity polarity); void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *pstate); }; @@ -61,7 +62,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c) }

static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, - struct pwm_device *pwm, bool enable) + struct pwm_device *pwm, bool enable, + enum pwm_polarity polarity) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN; @@ -91,14 +93,15 @@ static void rockchip_pwm_get_state_v1(struct pwm_chip *chip, }

static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, - struct pwm_device *pwm, bool enable) + struct pwm_device *pwm, bool enable, + enum pwm_polarity polarity) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | PWM_CONTINUOUS; u32 val;

- if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED) + if (polarity == PWM_POLARITY_INVERSED) enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE; else enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE; @@ -168,7 +171,6 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); unsigned long period, duty; u64 clk_rate, div; - int ret;

clk_rate = clk_get_rate(pc->clk);

@@ -185,15 +187,8 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, do_div(div, pc->data->prescaler * NSEC_PER_SEC); duty = div;

- ret = clk_enable(pc->clk); - if (ret) - return ret; - writel(period, pc->base + pc->data->regs.period); writel(duty, pc->base + pc->data->regs.duty); - writel(0, pc->base + pc->data->regs.cntr); - - clk_disable(pc->clk);

return 0; } @@ -211,43 +206,63 @@ static int rockchip_pwm_set_polarity(struct pwm_chip *chip, return 0; }

-static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + struct pwm_state curstate; + bool enabled; int ret;

+ pwm_get_state(pwm, &curstate); + enabled = curstate.enabled; + ret = clk_enable(pc->clk); if (ret) return ret;

- pc->data->set_enable(chip, pwm, true); + if (state->polarity != curstate.polarity && enabled) { + pc->data->set_enable(chip, pwm, false, state->polarity); + enabled = false; + }

- return 0; -} + ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period); + if (ret) { + if (enabled != curstate.enabled) + pc->data->set_enable(chip, pwm, !enabled, + state->polarity);

-static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + goto out; + }

- pc->data->set_enable(chip, pwm, false); + if (state->enabled != enabled) + pc->data->set_enable(chip, pwm, state->enabled, + state->polarity);

+ /* + * Update the state with the real hardware, which can differ a bit + * because of period/duty_cycle approximation. + */ + rockchip_pwm_get_state(chip, pwm, state); + +out: clk_disable(pc->clk); + + return ret; }

static const struct pwm_ops rockchip_pwm_ops_v1 = { .get_state = rockchip_pwm_get_state, .config = rockchip_pwm_config, - .enable = rockchip_pwm_enable, - .disable = rockchip_pwm_disable, + .apply = rockchip_pwm_apply, .owner = THIS_MODULE, };

static const struct pwm_ops rockchip_pwm_ops_v2 = { .get_state = rockchip_pwm_get_state, .config = rockchip_pwm_config, + .apply = rockchip_pwm_apply, .set_polarity = rockchip_pwm_set_polarity, - .enable = rockchip_pwm_enable, - .disable = rockchip_pwm_disable, .owner = THIS_MODULE, };

The current logic will disable the PWM clk even if a PWM was left enabled by the bootloader (because it's controlling a critical device like a regulator for example). Keep the PWM clk enabled if at least one PWM is enabled to avoid any glitches.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/pwm-sti.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index 0fbca94..bea1d17 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -343,7 +343,7 @@ static int sti_pwm_probe(struct platform_device *pdev) struct sti_pwm_compat_data *cdata; struct sti_pwm_chip *pc; struct resource *res; - int ret; + int i, ret;

pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL); if (!pc) @@ -394,7 +394,7 @@ static int sti_pwm_probe(struct platform_device *pdev) return -EINVAL; }

- ret = clk_prepare(pc->clk); + ret = clk_prepare_enable(pc->clk); if (ret) { dev_err(dev, "failed to prepare clock\n"); return ret; @@ -412,6 +412,19 @@ static int sti_pwm_probe(struct platform_device *pdev) return ret; }

+ /* + * Keep the PWM clk enabled if some PWMs appear to be up and + * running. + */ + for (i = 0; i < pc->chip.npwm; i++) { + struct pwm_state pstate; + + pwm_get_state(&pc->chip.pwms[i], &pstate); + if (pstate.enabled) + clk_enable(pc->clk); + } + clk_disable(pc->clk); + platform_set_drvdata(pdev, pc);

return 0;

The PWM attached to a PWM regulator device might have been previously configured by the bootloader. Make sure the bootloader and linux config are in sync, and adjust the PWM config if that's not the case.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/regulator/pwm-regulator.c | 50 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 9154c47..9590fb0 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -240,6 +240,52 @@ static int pwm_regulator_init_continuous(struct platform_device *pdev, return 0; }

+static int pwm_regulator_adjust_pwm_config(struct pwm_regulator_data *drvdata) +{ + struct pwm_state pstate = { }; + struct pwm_args pargs = { }; + + pwm_get_args(drvdata->pwm, &pargs); + pwm_get_state(drvdata->pwm, &pstate); + + /* + * if the current period is zero this either means the PWM driver + * does not support initial state retrieval or the PWM was not + * configured. + * In any case, we setup the new period and poloarity, and assign a + * duty_cycle of 0. + */ + if (!pstate.period) { + pstate.duty_cycle = 0; + pstate.period = pargs.period; + pstate.polarity = pargs.polarity; + + return pwm_apply_state(drvdata->pwm, &pstate); + } + + /* + * Adjust the PWM dutycycle/period based on the period value provided + * in PWM args. + */ + if (pargs.period != pstate.period) { + u64 dutycycle = (u64)pstate.duty_cycle * pargs.period; + + do_div(dutycycle, pstate.period); + pstate.duty_cycle = dutycycle; + pstate.period = pargs.period; + } + + /* + * If the polarity changed, we should also change the dutycycle value. + */ + if (pargs.polarity != pstate.polarity) { + pstate.polarity = pargs.polarity; + pstate.duty_cycle = pstate.period - pstate.duty_cycle; + } + + return pwm_apply_state(drvdata->pwm, &pstate); +} + static int pwm_regulator_probe(struct platform_device *pdev) { const struct regulator_init_data *init_data; @@ -283,6 +329,10 @@ static int pwm_regulator_probe(struct platform_device *pdev) return PTR_ERR(drvdata->pwm); }

+ ret = pwm_regulator_adjust_pwm_config(drvdata); + if (ret) + return ret; + regulator = devm_regulator_register(&pdev->dev, &drvdata->desc, &config); if (IS_ERR(regulator)) {

pwm_config/enable/disable() have been deprecated in favor of pwm_apply_state(). Replace all those calls with the equivalent pwm_get/apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/regulator/pwm-regulator.c | 54 ++++++++++++++++++++++++--------------- 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 9590fb0..42cc312 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -59,16 +59,18 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, unsigned selector) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); - struct pwm_args pargs = { }; - int dutycycle; + struct pwm_state pstate = { }; + u64 dutycycle; int ret;

- pwm_get_args(drvdata->pwm, &pargs); + pwm_get_state(drvdata->pwm, &pstate);

- dutycycle = (pargs.period * - drvdata->duty_cycle_table[selector].dutycycle) / 100; + dutycycle = drvdata->duty_cycle_table[selector].dutycycle; + dutycycle *= pstate.period; + do_div(dutycycle, 100); + pstate.duty_cycle = dutycycle;

- ret = pwm_config(drvdata->pwm, dutycycle, pargs.period); + ret = pwm_apply_state(drvdata->pwm, &pstate); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM\n"); return ret; @@ -93,24 +95,39 @@ static int pwm_regulator_list_voltage(struct regulator_dev *rdev, static int pwm_regulator_enable(struct regulator_dev *dev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); + struct pwm_state pstate = { }; + + pwm_get_state(drvdata->pwm, &pstate); + if (pstate.enabled) + return 0; + + pstate.enabled = true;

- return pwm_enable(drvdata->pwm); + return pwm_apply_state(drvdata->pwm, &pstate); }

static int pwm_regulator_disable(struct regulator_dev *dev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); + struct pwm_state pstate = { };

- pwm_disable(drvdata->pwm); + pwm_get_state(drvdata->pwm, &pstate); + if (!pstate.enabled) + return 0;

- return 0; + pstate.enabled = false; + + return pwm_apply_state(drvdata->pwm, &pstate); }

static int pwm_regulator_is_enabled(struct regulator_dev *dev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); + struct pwm_state pstate = { };

- return pwm_is_enabled(drvdata->pwm); + pwm_get_state(drvdata->pwm, &pstate); + + return pstate.enabled; }

/** @@ -138,25 +155,22 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev, { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); unsigned int ramp_delay = rdev->constraints->ramp_delay; - struct pwm_args pargs = { }; - int duty_cycle; + struct pwm_state pstate = { }; + u64 duty_cycle; int ret;

- pwm_get_args(drvdata->pwm, &pargs); + pwm_get_state(drvdata->pwm, &pstate); duty_cycle = pwm_voltage_to_duty_cycle_percentage(rdev, min_uV); + duty_cycle *= pstate.period; + do_div(duty_cycle, 100); + pstate.duty_cycle = duty_cycle;

- ret = pwm_config(drvdata->pwm, (pargs.period / 100) * duty_cycle, - pargs.period); + ret = pwm_apply_state(drvdata->pwm, &pstate); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM\n"); return ret; }

- ret = pwm_enable(drvdata->pwm); - if (ret) { - dev_err(&rdev->dev, "Failed to enable PWM\n"); - return ret; - } drvdata->volt_uV = min_uV;

/* Delay required by PWM regulator to settle to the new voltage */

The ->state field is currently initialized to 0, thus referencing the voltage selector at index 0, which might not reflect the current voltage value. If possible, retrieve the current voltage selector from the PWM state, else return -EINVAL.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com Tested-by: Heiko Stuebner heiko@sntech.de Acked-by: Mark Brown broonie@kernel.org --- drivers/regulator/pwm-regulator.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 42cc312..9374796 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -48,10 +48,35 @@ struct pwm_voltages { /** * Voltage table call-backs */ +static void pwm_regulator_init_state(struct regulator_dev *rdev) +{ + struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev); + struct pwm_state pwm_state; + unsigned int dutycycle; + int i; + + pwm_get_state(drvdata->pwm, &pwm_state); + + if (!pwm_state.period) + return; + + dutycycle = (pwm_state.duty_cycle * 100) / pwm_state.period; + + for (i = 0; i < rdev->desc->n_voltages; i++) { + if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) { + drvdata->state = i; + return; + } + } +} + static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev) { struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);

+ if (drvdata->state < 0) + pwm_regulator_init_state(rdev); + return drvdata->state; }

@@ -234,6 +259,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev, return ret; }

+ drvdata->state = -EINVAL; drvdata->duty_cycle_table = duty_cycle_table; memcpy(&drvdata->ops, &pwm_regulator_voltage_table_ops, sizeof(drvdata->ops));

Update the PWM subsystem documentation to reflect the atomic PWM changes.

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- Documentation/pwm.txt | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/Documentation/pwm.txt b/Documentation/pwm.txt index ca895fd..cb25fca 100644 --- a/Documentation/pwm.txt +++ b/Documentation/pwm.txt @@ -42,9 +42,23 @@ variants of these functions, devm_pwm_get() and devm_pwm_put(), also exist.

After being requested, a PWM has to be configured using:

-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns); +int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *pstate);

-To start/stop toggling the PWM output use pwm_enable()/pwm_disable(). +This API controls both the PWM period/duty_cycle config and the +enable/disable state. + +The legacy pwm_config(), pwm_enable() and pwm_disable() are now deprecated, +and should be replaced by pwm_apply_state() calls. + +The PWM user API also allows one to query the PWM state with pwm_get_state(). + +In addition to the PWM state, the PWM API also exposes PWM arguments, which +are the reference PWM config one should use on this PWM. +PWM arguments are usually platform-specific and allows the PWM user to only +care about dutycycle relatively to the full period (like, duty = 50% of the +period). struct pwm_args contains 2 fields (period and polarity) and should +be used to set the initial PWM config (usually done in the probe function +of the PWM user). PWM arguments are retrieved with pwm_get_args().

Using PWMs with the sysfs interface ----------------------------------- @@ -105,6 +119,15 @@ goes low for the remainder of the period. Conversely, a signal with inversed polarity starts low for the duration of the duty cycle and goes high for the remainder of the period.

+Drivers are encouraged to implement ->apply() instead of the legacy +->enable(), ->disable() and ->config() methods. Doing that should provide +atomicity in the PWM config workflow, which is required when the PWM controls +a critical device (like a regulator). + +The implementation of ->get_state() (a method used to retrieve initial PWM +state) is also encouraged for the same reason: letting the PWM user know +about the current PWM state would allow him to avoid glitches. + Locking -------

Some PWM drivers are calling the deprecated pwm_disable() function in their pwm->free() or pdev->remove() function. Replace those calls by the pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/pwm/pwm-lpc18xx-sct.c | 7 +++++-- drivers/pwm/pwm-lpc32xx.c | 9 +++++++-- drivers/pwm/pwm-spear.c | 9 +++++++-- drivers/pwm/pwm-sti.c | 9 +++++++-- 4 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c index 19dc64c..c4d7cb1 100644 --- a/drivers/pwm/pwm-lpc18xx-sct.c +++ b/drivers/pwm/pwm-lpc18xx-sct.c @@ -305,9 +305,12 @@ static void lpc18xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip); struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm); + struct pwm_state pstate;

- pwm_disable(pwm); - pwm_set_duty_cycle(pwm, 0); + pwm_get_state(pwm, &pstate); + pstate.duty_cycle = 0; + pstate.enabled = false; + pwm_apply_state(pwm, &pstate); clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map); }

diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c index 4d470c1..95870e0 100644 --- a/drivers/pwm/pwm-lpc32xx.c +++ b/drivers/pwm/pwm-lpc32xx.c @@ -138,8 +138,13 @@ static int lpc32xx_pwm_remove(struct platform_device *pdev) struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev); unsigned int i;

- for (i = 0; i < lpc32xx->chip.npwm; i++) - pwm_disable(&lpc32xx->chip.pwms[i]); + for (i = 0; i < lpc32xx->chip.npwm; i++) { + struct pwm_state pstate; + + pwm_get_state(&lpc32xx->chip.pwms[i], &pstate); + pstate.enabled = false; + pwm_apply_state(&lpc32xx->chip.pwms[i], &pstate); + }

return pwmchip_remove(&lpc32xx->chip); } diff --git a/drivers/pwm/pwm-spear.c b/drivers/pwm/pwm-spear.c index 6c6b44f..2ee4cd5 100644 --- a/drivers/pwm/pwm-spear.c +++ b/drivers/pwm/pwm-spear.c @@ -233,8 +233,13 @@ static int spear_pwm_remove(struct platform_device *pdev) struct spear_pwm_chip *pc = platform_get_drvdata(pdev); int i;

- for (i = 0; i < NUM_PWM; i++) - pwm_disable(&pc->chip.pwms[i]); + for (i = 0; i < NUM_PWM; i++) { + struct pwm_state pstate; + + pwm_get_state(&pc->chip.pwms[i], &pstate); + pstate.enabled = false; + pwm_apply_state(&pc->chip.pwms[i], &pstate); + }

/* clk was prepared in probe, hence unprepare it here */ clk_unprepare(pc->clk); diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index bea1d17..0ec44a8 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -435,8 +435,13 @@ static int sti_pwm_remove(struct platform_device *pdev) struct sti_pwm_chip *pc = platform_get_drvdata(pdev); unsigned int i;

- for (i = 0; i < pc->cdata->num_chan; i++) - pwm_disable(&pc->chip.pwms[i]); + for (i = 0; i < pc->cdata->num_chan; i++) { + struct pwm_state pstate; + + pwm_get_state(&pc->chip.pwms[i], &pstate); + pstate.enabled = false; + pwm_apply_state(&pc->chip.pwms[i], &pstate); + }

clk_unprepare(pc->clk);

pwm_config/enable/disable() have been deprecated and should be replaced by pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/input/misc/max77693-haptic.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c index cf6aac0..aef7dc4 100644 --- a/drivers/input/misc/max77693-haptic.c +++ b/drivers/input/misc/max77693-haptic.c @@ -70,13 +70,16 @@ struct max77693_haptic {

static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic) { + struct pwm_state pstate; struct pwm_args pargs = { }; - int delta; int error;

pwm_get_args(haptic->pwm_dev, &pargs); - delta = (pargs.period + haptic->pwm_duty) / 2; - error = pwm_config(haptic->pwm_dev, delta, pargs.period); + pwm_get_state(haptic->pwm_dev, &pstate); + + pstate.period = pargs.period; + pstate.duty_cycle = (pargs.period + haptic->pwm_duty) / 2; + error = pwm_apply_state(haptic->pwm_dev, &pstate); if (error) { dev_err(haptic->dev, "failed to configure pwm: %d\n", error); return error; @@ -161,12 +164,16 @@ static int max77693_haptic_lowsys(struct max77693_haptic *haptic, bool enable)

static void max77693_haptic_enable(struct max77693_haptic *haptic) { + struct pwm_state pstate; int error;

if (haptic->enabled) return;

- error = pwm_enable(haptic->pwm_dev); + pwm_get_state(haptic->pwm_dev, &pstate); + pstate.enabled = true; + + error = pwm_apply_state(haptic->pwm_dev, &pstate); if (error) { dev_err(haptic->dev, "failed to enable haptic pwm device: %d\n", error); @@ -188,11 +195,13 @@ static void max77693_haptic_enable(struct max77693_haptic *haptic) err_enable_config: max77693_haptic_lowsys(haptic, false); err_enable_lowsys: - pwm_disable(haptic->pwm_dev); + pstate.enabled = false; + pwm_apply_state(haptic->pwm_dev, &pstate); }

static void max77693_haptic_disable(struct max77693_haptic *haptic) { + struct pwm_state pstate; int error;

if (!haptic->enabled) @@ -206,7 +215,9 @@ static void max77693_haptic_disable(struct max77693_haptic *haptic) if (error) goto err_disable_lowsys;

- pwm_disable(haptic->pwm_dev); + pwm_get_state(haptic->pwm_dev, &pstate); + pstate.enabled = false; + pwm_apply_state(haptic->pwm_dev, &pstate); haptic->enabled = false;

return;

pwm_config/enable/disable() have been deprecated and should be replaced by pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/input/misc/pwm-beeper.c | 46 +++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c index f2261ab..36c9897 100644 --- a/drivers/input/misc/pwm-beeper.c +++ b/drivers/input/misc/pwm-beeper.c @@ -34,7 +34,7 @@ static int pwm_beeper_event(struct input_dev *input, { int ret = 0; struct pwm_beeper *beeper = input_get_drvdata(input); - unsigned long period; + struct pwm_state pstate;

if (type != EV_SND || value < 0) return -EINVAL; @@ -49,19 +49,22 @@ static int pwm_beeper_event(struct input_dev *input, return -EINVAL; }

+ pwm_get_state(beeper->pwm, &pstate); + if (value == 0) { - pwm_disable(beeper->pwm); + pstate.enabled = false; } else { - period = HZ_TO_NANOSECONDS(value); - ret = pwm_config(beeper->pwm, period / 2, period); - if (ret) - return ret; - ret = pwm_enable(beeper->pwm); - if (ret) - return ret; - beeper->period = period; + pstate.enabled = false; + pstate.period = HZ_TO_NANOSECONDS(value); + pstate.duty_cycle = pstate.period / 2; }

+ ret = pwm_apply_state(beeper->pwm, &pstate); + if (ret) + return ret; + + beeper->period = value ? pstate.period : 0; + return 0; }

@@ -132,10 +135,13 @@ err_free: static int pwm_beeper_remove(struct platform_device *pdev) { struct pwm_beeper *beeper = platform_get_drvdata(pdev); + struct pwm_state pstate;

input_unregister_device(beeper->input);

- pwm_disable(beeper->pwm); + pwm_get_state(beeper->pwm, &pstate); + pstate.enabled = false; + pwm_apply_state(beeper->pwm, &pstate); pwm_free(beeper->pwm);

kfree(beeper); @@ -147,8 +153,13 @@ static int __maybe_unused pwm_beeper_suspend(struct device *dev) { struct pwm_beeper *beeper = dev_get_drvdata(dev);

- if (beeper->period) - pwm_disable(beeper->pwm); + if (beeper->period) { + struct pwm_state pstate; + + pwm_get_state(beeper->pwm, &pstate); + pstate.enabled = false; + pwm_apply_state(beeper->pwm, &pstate); + }

return 0; } @@ -158,8 +169,13 @@ static int __maybe_unused pwm_beeper_resume(struct device *dev) struct pwm_beeper *beeper = dev_get_drvdata(dev);

if (beeper->period) { - pwm_config(beeper->pwm, beeper->period / 2, beeper->period); - pwm_enable(beeper->pwm); + struct pwm_state pstate; + + pwm_get_state(beeper->pwm, &pstate); + pstate.period = beeper->period; + pstate.duty_cycle = beeper->period / 2; + pstate.enabled = true; + pwm_apply_state(beeper->pwm, &pstate); }

return 0;

pwm_config/enable/disable() have been deprecated and should be replaced by pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/video/backlight/lm3630a_bl.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c index 3d16bd6..fdad23c 100644 --- a/drivers/video/backlight/lm3630a_bl.c +++ b/drivers/video/backlight/lm3630a_bl.c @@ -162,14 +162,16 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)

static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max) { - unsigned int period = pchip->pdata->pwm_period; - unsigned int duty = br * period / br_max; + struct pwm_state pstate;

- pwm_config(pchip->pwmd, duty, period); - if (duty) - pwm_enable(pchip->pwmd); + pwm_get_state(pchip->pwmd, &pstate); + pstate.period = pchip->pdata->pwm_period; + pstate.duty_cycle = br * pstate.period / br_max; + if (pstate.duty_cycle) + pstate.enabled = true; else - pwm_disable(pchip->pwmd); + pstate.enabled = false; + pwm_apply_state(pchip->pwmd, &pstate); }

/* update and get brightness */

pwm_config/enable/disable() have been deprecated and should be replaced by pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/video/backlight/lp8788_bl.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/video/backlight/lp8788_bl.c b/drivers/video/backlight/lp8788_bl.c index 5d583d7..521c730 100644 --- a/drivers/video/backlight/lp8788_bl.c +++ b/drivers/video/backlight/lp8788_bl.c @@ -124,16 +124,13 @@ static int lp8788_backlight_configure(struct lp8788_bl *bl)

static void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br) { - unsigned int period; - unsigned int duty; struct device *dev; + struct pwm_state pstate; struct pwm_device *pwm;

if (!bl->pdata) return;

- period = bl->pdata->period_ns; - duty = br * period / max_br; dev = bl->lp->dev;

/* request PWM device with the consumer name */ @@ -147,11 +144,15 @@ static void lp8788_pwm_ctrl(struct lp8788_bl *bl, int br, int max_br) bl->pwm = pwm; }

- pwm_config(bl->pwm, duty, period); - if (duty) - pwm_enable(bl->pwm); + pwm_get_state(bl->pwm, &pstate); + pstate.period = bl->pdata->period_ns; + pstate.duty_cycle = br * pstate.period / max_br; + if (pstate.duty_cycle) + pstate.enabled = true; else - pwm_disable(bl->pwm); + pstate.enabled = false; + + pwm_apply_state(bl->pwm, &pstate); }

static int lp8788_bl_update_status(struct backlight_device *bl_dev)

pwm_config/enable/disable() have been deprecated and should be replaced by pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- drivers/video/fbdev/ssd1307fb.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index df9c63a..ed9a115 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -289,6 +289,8 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) struct pwm_args pargs = { };

if (par->device_info->need_pwm) { + struct pwm_state pstate; + par->pwm = pwm_get(&par->client->dev, NULL); if (IS_ERR(par->pwm)) { dev_err(&par->client->dev, "Could not get PWM from device tree!\n"); @@ -296,10 +298,14 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) }

pwm_get_args(par->pwm, &pargs); + pwm_get_state(par->pwm, &pstate); par->pwm_period = pargs.period; + /* Enable the PWM */ - pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period); - pwm_enable(par->pwm); + pstate.period = pargs.period; + pstate.duty_cycle = pstate.period / 2; + pstate.enabled = true; + pwm_apply_state(par->pwm, &pstate);

dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n", par->pwm->pwm, par->pwm_period); @@ -685,8 +691,12 @@ static int ssd1307fb_probe(struct i2c_client *client, bl_init_error: unregister_framebuffer(info); panel_init_error: - if (par->device_info->need_pwm) { - pwm_disable(par->pwm); + if (par->device_info->need_pwm && par->pwm) { + struct pwm_state pstate; + + pwm_get_state(par->pwm, &pstate); + pstate.enabled = false; + pwm_apply_state(par->pwm, &pstate); pwm_put(par->pwm); }; reset_oled_error: @@ -707,7 +717,11 @@ static int ssd1307fb_remove(struct i2c_client *client)

unregister_framebuffer(info); if (par->device_info->need_pwm) { - pwm_disable(par->pwm); + struct pwm_state pstate; + + pwm_get_state(par->pwm, &pstate); + pstate.enabled = false; + pwm_apply_state(par->pwm, &pstate); pwm_put(par->pwm); }; fb_deferred_io_cleanup(info);

Replace pwm_disable/enable/config() by pwm_apply_state().

Signed-off-by: Boris Brezillon boris.brezillon@free-electrons.com --- arch/arm/mach-s3c24xx/mach-rx1950.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/arm/mach-s3c24xx/mach-rx1950.c b/arch/arm/mach-s3c24xx/mach-rx1950.c index 774c982..2dc9487 100644 --- a/arch/arm/mach-s3c24xx/mach-rx1950.c +++ b/arch/arm/mach-s3c24xx/mach-rx1950.c @@ -384,10 +384,15 @@ static struct pwm_device *lcd_pwm;

static void rx1950_lcd_power(int enable) { + struct pwm_state pstate; int i; static int enabled; + if (enabled == enable) return; + + pwm_get_state(lcd_pwm, &pstate); + if (!enable) {

/* GPC11-GPC15->OUTPUT */ @@ -433,15 +438,21 @@ static void rx1950_lcd_power(int enable)

/* GPB1->OUTPUT, GPB1->0 */ gpio_direction_output(S3C2410_GPB(1), 0); - pwm_config(lcd_pwm, 0, LCD_PWM_PERIOD); + + pstate.enabled = false; + pstate.period = LCD_PWM_PERIOD; + pstate.duty_cycle = 0; + pwm_apply_state(lcd_pwm, &pstate); pwm_disable(lcd_pwm);

/* GPC0->0, GPC10->0 */ gpio_direction_output(S3C2410_GPC(0), 0); gpio_direction_output(S3C2410_GPC(10), 0); } else { - pwm_config(lcd_pwm, LCD_PWM_DUTY, LCD_PWM_PERIOD); - pwm_enable(lcd_pwm); + pstate.enabled = true; + pstate.period = LCD_PWM_PERIOD; + pstate.duty_cycle = LCD_PWM_DUTY; + pwm_apply_state(lcd_pwm, &pstate);

gpio_direction_output(S3C2410_GPC(0), 1); gpio_direction_output(S3C2410_GPC(5), 1);