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Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/core.c224
-rw-r--r--drivers/pwm/pwm-atmel-hlcdc.c2
-rw-r--r--drivers/pwm/pwm-clps711x.c2
-rw-r--r--drivers/pwm/pwm-crc.c2
-rw-r--r--drivers/pwm/pwm-lpc18xx-sct.c2
-rw-r--r--drivers/pwm/pwm-omap-dmtimer.c2
-rw-r--r--drivers/pwm/pwm-pxa.c2
-rw-r--r--drivers/pwm/pwm-rcar.c2
-rw-r--r--drivers/pwm/pwm-sun4i.c3
-rw-r--r--drivers/pwm/sysfs.c70
10 files changed, 206 insertions, 105 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 7831bc6b5..ed337a8c3 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -75,6 +75,7 @@ static void free_pwms(struct pwm_chip *chip)
for (i = 0; i < chip->npwm; i++) {
struct pwm_device *pwm = &chip->pwms[i];
+
radix_tree_delete(&pwm_tree, pwm->pwm);
}
@@ -146,12 +147,12 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
if (IS_ERR(pwm))
return pwm;
- pwm_set_period(pwm, args->args[1]);
+ pwm->args.period = args->args[1];
if (args->args[2] & PWM_POLARITY_INVERTED)
- pwm_set_polarity(pwm, PWM_POLARITY_INVERSED);
+ pwm->args.polarity = PWM_POLARITY_INVERSED;
else
- pwm_set_polarity(pwm, PWM_POLARITY_NORMAL);
+ pwm->args.polarity = PWM_POLARITY_NORMAL;
return pwm;
}
@@ -172,7 +173,7 @@ of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
if (IS_ERR(pwm))
return pwm;
- pwm_set_period(pwm, args->args[1]);
+ pwm->args.period = args->args[1];
return pwm;
}
@@ -226,6 +227,19 @@ void *pwm_get_chip_data(struct pwm_device *pwm)
}
EXPORT_SYMBOL_GPL(pwm_get_chip_data);
+static bool pwm_ops_check(const struct pwm_ops *ops)
+{
+ /* driver supports legacy, non-atomic operation */
+ if (ops->config && ops->enable && ops->disable)
+ return true;
+
+ /* driver supports atomic operation */
+ if (ops->apply)
+ return true;
+
+ return false;
+}
+
/**
* pwmchip_add_with_polarity() - register a new PWM chip
* @chip: the PWM chip to add
@@ -244,8 +258,10 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
unsigned int i;
int ret;
- if (!chip || !chip->dev || !chip->ops || !chip->ops->config ||
- !chip->ops->enable || !chip->ops->disable || !chip->npwm)
+ if (!chip || !chip->dev || !chip->ops || !chip->npwm)
+ return -EINVAL;
+
+ if (!pwm_ops_check(chip->ops))
return -EINVAL;
mutex_lock(&pwm_lock);
@@ -254,7 +270,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
if (ret < 0)
goto out;
- chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL);
+ chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
if (!chip->pwms) {
ret = -ENOMEM;
goto out;
@@ -268,8 +284,10 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip,
pwm->chip = chip;
pwm->pwm = chip->base + i;
pwm->hwpwm = i;
- pwm->polarity = polarity;
- mutex_init(&pwm->lock);
+ 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);
}
@@ -429,107 +447,139 @@ void pwm_free(struct pwm_device *pwm)
EXPORT_SYMBOL_GPL(pwm_free);
/**
- * pwm_config() - change a PWM device configuration
+ * pwm_apply_state() - atomically apply a new state to a PWM device
* @pwm: PWM device
- * @duty_ns: "on" time (in nanoseconds)
- * @period_ns: duration (in nanoseconds) of one cycle
- *
- * Returns: 0 on success or a negative error code on failure.
+ * @state: new state to apply. This can be adjusted by the PWM driver
+ * if the requested config is not achievable, for example,
+ * ->duty_cycle and ->period might be approximated.
*/
-int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
+int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state)
{
int err;
- if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
+ if (!pwm || !state || !state->period ||
+ state->duty_cycle > state->period)
return -EINVAL;
- err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
- if (err)
- return err;
-
- pwm->duty_cycle = duty_ns;
- pwm->period = period_ns;
+ if (!memcmp(state, &pwm->state, sizeof(*state)))
+ return 0;
- return 0;
-}
-EXPORT_SYMBOL_GPL(pwm_config);
+ if (pwm->chip->ops->apply) {
+ err = pwm->chip->ops->apply(pwm->chip, pwm, state);
+ if (err)
+ return err;
-/**
- * pwm_set_polarity() - configure the polarity of a PWM signal
- * @pwm: PWM device
- * @polarity: new polarity of the PWM signal
- *
- * Note that the polarity cannot be configured while the PWM device is
- * enabled.
- *
- * Returns: 0 on success or a negative error code on failure.
- */
-int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
-{
- int err;
+ pwm->state = *state;
+ } else {
+ /*
+ * FIXME: restore the initial state in case of error.
+ */
+ if (state->polarity != pwm->state.polarity) {
+ if (!pwm->chip->ops->set_polarity)
+ return -ENOTSUPP;
+
+ /*
+ * Changing the polarity of a running PWM is
+ * only allowed when the PWM driver implements
+ * ->apply().
+ */
+ if (pwm->state.enabled) {
+ pwm->chip->ops->disable(pwm->chip, pwm);
+ pwm->state.enabled = false;
+ }
+
+ err = pwm->chip->ops->set_polarity(pwm->chip, pwm,
+ state->polarity);
+ if (err)
+ return err;
+
+ pwm->state.polarity = state->polarity;
+ }
- if (!pwm || !pwm->chip->ops)
- return -EINVAL;
+ if (state->period != pwm->state.period ||
+ state->duty_cycle != pwm->state.duty_cycle) {
+ err = pwm->chip->ops->config(pwm->chip, pwm,
+ state->duty_cycle,
+ state->period);
+ if (err)
+ return err;
- if (!pwm->chip->ops->set_polarity)
- return -ENOSYS;
+ pwm->state.duty_cycle = state->duty_cycle;
+ pwm->state.period = state->period;
+ }
- mutex_lock(&pwm->lock);
+ if (state->enabled != pwm->state.enabled) {
+ if (state->enabled) {
+ err = pwm->chip->ops->enable(pwm->chip, pwm);
+ if (err)
+ return err;
+ } else {
+ pwm->chip->ops->disable(pwm->chip, pwm);
+ }
- if (pwm_is_enabled(pwm)) {
- err = -EBUSY;
- goto unlock;
+ pwm->state.enabled = state->enabled;
+ }
}
- err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
- if (err)
- goto unlock;
-
- pwm->polarity = polarity;
-
-unlock:
- mutex_unlock(&pwm->lock);
- return err;
+ return 0;
}
-EXPORT_SYMBOL_GPL(pwm_set_polarity);
+EXPORT_SYMBOL_GPL(pwm_apply_state);
/**
- * pwm_enable() - start a PWM output toggling
+ * pwm_adjust_config() - adjust the current PWM config to the PWM arguments
* @pwm: PWM device
*
- * Returns: 0 on success or a negative error code on failure.
+ * This function will adjust the PWM config to the PWM arguments provided
+ * by the DT or PWM lookup table. This is particularly useful to adapt
+ * the bootloader config to the Linux one.
*/
-int pwm_enable(struct pwm_device *pwm)
+int pwm_adjust_config(struct pwm_device *pwm)
{
- int err = 0;
+ struct pwm_state state;
+ struct pwm_args pargs;
- if (!pwm)
- return -EINVAL;
+ pwm_get_args(pwm, &pargs);
+ pwm_get_state(pwm, &state);
- mutex_lock(&pwm->lock);
+ /*
+ * If the current period is zero it means that either the PWM driver
+ * does not support initial state retrieval or the PWM has not yet
+ * been configured.
+ *
+ * In either case, we setup the new period and polarity, and assign a
+ * duty cycle of 0.
+ */
+ if (!state.period) {
+ state.duty_cycle = 0;
+ state.period = pargs.period;
+ state.polarity = pargs.polarity;
- 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);
+ return pwm_apply_state(pwm, &state);
}
- mutex_unlock(&pwm->lock);
+ /*
+ * Adjust the PWM duty cycle/period based on the period value provided
+ * in PWM args.
+ */
+ if (pargs.period != state.period) {
+ u64 dutycycle = (u64)state.duty_cycle * pargs.period;
- return err;
-}
-EXPORT_SYMBOL_GPL(pwm_enable);
+ do_div(dutycycle, state.period);
+ state.duty_cycle = dutycycle;
+ state.period = pargs.period;
+ }
-/**
- * pwm_disable() - stop a PWM output toggling
- * @pwm: PWM device
- */
-void pwm_disable(struct pwm_device *pwm)
-{
- if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
- pwm->chip->ops->disable(pwm->chip, pwm);
+ /*
+ * If the polarity changed, we should also change the duty cycle.
+ */
+ if (pargs.polarity != state.polarity) {
+ state.polarity = pargs.polarity;
+ state.duty_cycle = state.period - state.duty_cycle;
+ }
+
+ return pwm_apply_state(pwm, &state);
}
-EXPORT_SYMBOL_GPL(pwm_disable);
+EXPORT_SYMBOL_GPL(pwm_adjust_config);
static struct pwm_chip *of_node_to_pwmchip(struct device_node *np)
{
@@ -751,8 +801,8 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
if (IS_ERR(pwm))
goto out;
- pwm_set_period(pwm, chosen->period);
- pwm_set_polarity(pwm, chosen->polarity);
+ pwm->args.period = chosen->period;
+ pwm->args.polarity = chosen->polarity;
out:
mutex_unlock(&pwm_lookup_lock);
@@ -900,15 +950,23 @@ 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 state;
+
+ pwm_get_state(pwm, &state);
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 (state.enabled)
seq_puts(s, " enabled");
+ seq_printf(s, " period: %u ns", state.period);
+ seq_printf(s, " duty: %u ns", state.duty_cycle);
+ seq_printf(s, " polarity: %s",
+ state.polarity ? "inverse" : "normal");
+
seq_puts(s, "\n");
}
}
diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
index f994c7eaf..14fc011fa 100644
--- a/drivers/pwm/pwm-atmel-hlcdc.c
+++ b/drivers/pwm/pwm-atmel-hlcdc.c
@@ -272,7 +272,7 @@ static int atmel_hlcdc_pwm_probe(struct platform_device *pdev)
chip->chip.of_pwm_n_cells = 3;
chip->chip.can_sleep = 1;
- ret = pwmchip_add(&chip->chip);
+ ret = pwmchip_add_with_polarity(&chip->chip, PWM_POLARITY_INVERSED);
if (ret) {
clk_disable_unprepare(hlcdc->periph_clk);
return ret;
diff --git a/drivers/pwm/pwm-clps711x.c b/drivers/pwm/pwm-clps711x.c
index a80c10803..7d335422c 100644
--- a/drivers/pwm/pwm-clps711x.c
+++ b/drivers/pwm/pwm-clps711x.c
@@ -60,7 +60,7 @@ static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
return -EINVAL;
/* Store constant period value */
- pwm_set_period(pwm, DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq));
+ pwm->args.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq);
return 0;
}
diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
index 7101c7020..bd0ebd048 100644
--- a/drivers/pwm/pwm-crc.c
+++ b/drivers/pwm/pwm-crc.c
@@ -75,7 +75,7 @@ static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
return -EINVAL;
}
- if (pwm->period != period_ns) {
+ if (pwm_get_period(pwm) != period_ns) {
int clk_div;
/* changing the clk divisor, need to disable fisrt */
diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
index 9861fed4e..19dc64cab 100644
--- a/drivers/pwm/pwm-lpc18xx-sct.c
+++ b/drivers/pwm/pwm-lpc18xx-sct.c
@@ -249,7 +249,7 @@ static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
LPC18XX_PWM_EVSTATEMSK_ALL);
- if (pwm->polarity == PWM_POLARITY_NORMAL) {
+ if (pwm_get_polarity(pwm) == PWM_POLARITY_NORMAL) {
set_event = lpc18xx_pwm->period_event;
clear_event = lpc18xx_data->duty_event;
res_action = LPC18XX_PWM_RES_SET;
diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c
index b7e6ecba7..3e95090cd 100644
--- a/drivers/pwm/pwm-omap-dmtimer.c
+++ b/drivers/pwm/pwm-omap-dmtimer.c
@@ -192,7 +192,7 @@ static int pwm_omap_dmtimer_config(struct pwm_chip *chip,
load_value, load_value, match_value, match_value);
omap->pdata->set_pwm(omap->dm_timer,
- pwm->polarity == PWM_POLARITY_INVERSED,
+ pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED,
true,
PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE);
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
index cb2f7024c..58b709f29 100644
--- a/drivers/pwm/pwm-pxa.c
+++ b/drivers/pwm/pwm-pxa.c
@@ -160,7 +160,7 @@ pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
if (IS_ERR(pwm))
return pwm;
- pwm_set_period(pwm, args->args[0]);
+ pwm->args.period = args->args[0];
return pwm;
}
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index 7b8ac0678..1c85ecc9e 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -157,7 +157,7 @@ static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return div;
/* Let the core driver set pwm->period if disabled and duty_ns == 0 */
- if (!test_bit(PWMF_ENABLED, &pwm->flags) && !duty_ns)
+ if (!pwm_is_enabled(pwm) && !duty_ns)
return 0;
rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR);
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 67af9f623..03a99a53c 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -354,7 +354,8 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
val = sun4i_pwm_readl(pwm, PWM_CTRL_REG);
for (i = 0; i < pwm->chip.npwm; i++)
if (!(val & BIT_CH(PWM_ACT_STATE, i)))
- pwm->chip.pwms[i].polarity = PWM_POLARITY_INVERSED;
+ pwm_set_polarity(&pwm->chip.pwms[i],
+ PWM_POLARITY_INVERSED);
clk_disable_unprepare(pwm->clk);
return 0;
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 9c90886f4..01695d48d 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)
@@ -45,15 +46,20 @@ static ssize_t period_show(struct device *child,
char *buf)
{
const struct pwm_device *pwm = child_to_pwm_device(child);
+ struct pwm_state state;
- return sprintf(buf, "%u\n", pwm_get_period(pwm));
+ pwm_get_state(pwm, &state);
+
+ return sprintf(buf, "%u\n", state.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;
+ struct pwm_state state;
unsigned int val;
int ret;
@@ -61,7 +67,11 @@ static ssize_t period_store(struct device *child,
if (ret)
return ret;
- ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val);
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ state.period = val;
+ ret = pwm_apply_state(pwm, &state);
+ mutex_unlock(&export->lock);
return ret ? : size;
}
@@ -71,15 +81,20 @@ static ssize_t duty_cycle_show(struct device *child,
char *buf)
{
const struct pwm_device *pwm = child_to_pwm_device(child);
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
- return sprintf(buf, "%u\n", pwm_get_duty_cycle(pwm));
+ return sprintf(buf, "%u\n", state.duty_cycle);
}
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;
+ struct pwm_state state;
unsigned int val;
int ret;
@@ -87,7 +102,11 @@ static ssize_t duty_cycle_store(struct device *child,
if (ret)
return ret;
- ret = pwm_config(pwm, val, pwm_get_period(pwm));
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ state.duty_cycle = val;
+ ret = pwm_apply_state(pwm, &state);
+ mutex_unlock(&export->lock);
return ret ? : size;
}
@@ -97,33 +116,46 @@ static ssize_t enable_show(struct device *child,
char *buf)
{
const struct pwm_device *pwm = child_to_pwm_device(child);
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
- return sprintf(buf, "%d\n", pwm_is_enabled(pwm));
+ return sprintf(buf, "%d\n", state.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;
+ struct pwm_state state;
int val, ret;
ret = kstrtoint(buf, 0, &val);
if (ret)
return ret;
+ mutex_lock(&export->lock);
+
+ pwm_get_state(pwm, &state);
+
switch (val) {
case 0:
- pwm_disable(pwm);
+ state.enabled = false;
break;
case 1:
- ret = pwm_enable(pwm);
+ state.enabled = true;
break;
default:
ret = -EINVAL;
- break;
+ goto unlock;
}
+ ret = pwm_apply_state(pwm, &state);
+
+unlock:
+ mutex_unlock(&export->lock);
return ret ? : size;
}
@@ -133,8 +165,11 @@ static ssize_t polarity_show(struct device *child,
{
const struct pwm_device *pwm = child_to_pwm_device(child);
const char *polarity = "unknown";
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
- switch (pwm_get_polarity(pwm)) {
+ switch (state.polarity) {
case PWM_POLARITY_NORMAL:
polarity = "normal";
break;
@@ -151,8 +186,10 @@ 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;
+ struct pwm_state state;
int ret;
if (sysfs_streq(buf, "normal"))
@@ -162,7 +199,11 @@ static ssize_t polarity_store(struct device *child,
else
return -EINVAL;
- ret = pwm_set_polarity(pwm, polarity);
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ state.polarity = polarity;
+ ret = pwm_apply_state(pwm, &state);
+ mutex_unlock(&export->lock);
return ret ? : size;
}
@@ -203,6 +244,7 @@ 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;
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-04 17:02:22 +0000