Merge branch 'for-4.8/drivers' into for-next
diff --git a/Documentation/ABI/testing/sysfs-class-pwm b/Documentation/ABI/testing/sysfs-class-pwm
index c479d77..c20e613 100644
--- a/Documentation/ABI/testing/sysfs-class-pwm
+++ b/Documentation/ABI/testing/sysfs-class-pwm
@@ -77,3 +77,12 @@
Enable/disable the PWM signal.
0 is disabled
1 is enabled
+
+What: /sys/class/pwm/pwmchipN/pwmX/capture
+Date: June 2016
+KernelVersion: 4.8
+Contact: Lee Jones <lee.jones@linaro.org>
+Description:
+ Capture information about a PWM signal. The output format is a
+ pair unsigned integers (period and duty cycle), separated by a
+ single space.
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index dba3843..0dbd29e 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -457,7 +457,8 @@
{
int err;
- if (!pwm)
+ if (!pwm || !state || !state->period ||
+ state->duty_cycle > state->period)
return -EINVAL;
if (!memcmp(state, &pwm->state, sizeof(*state)))
@@ -525,6 +526,33 @@
EXPORT_SYMBOL_GPL(pwm_apply_state);
/**
+ * pwm_capture() - capture and report a PWM signal
+ * @pwm: PWM device
+ * @result: structure to fill with capture result
+ * @timeout: time to wait, in milliseconds, before giving up on capture
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
+ unsigned long timeout)
+{
+ int err;
+
+ if (!pwm || !pwm->chip->ops)
+ return -EINVAL;
+
+ if (!pwm->chip->ops->capture)
+ return -ENOSYS;
+
+ mutex_lock(&pwm_lock);
+ err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
+ mutex_unlock(&pwm_lock);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(pwm_capture);
+
+/**
* pwm_adjust_config() - adjust the current PWM config to the PWM arguments
* @pwm: PWM device
*
diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c
index f994c7e..14fc011 100644
--- a/drivers/pwm/pwm-atmel-hlcdc.c
+++ b/drivers/pwm/pwm-atmel-hlcdc.c
@@ -272,7 +272,7 @@
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/sysfs.c b/drivers/pwm/sysfs.c
index d985992..18ed725 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -152,7 +152,7 @@
goto unlock;
}
- pwm_apply_state(pwm, &state);
+ ret = pwm_apply_state(pwm, &state);
unlock:
mutex_unlock(&export->lock);
@@ -208,16 +208,33 @@
return ret ? : size;
}
+static ssize_t capture_show(struct device *child,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pwm_device *pwm = child_to_pwm_device(child);
+ struct pwm_capture result;
+ int ret;
+
+ ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
+ if (ret)
+ return ret;
+
+ return sprintf(buf, "%u %u\n", result.period, result.duty_cycle);
+}
+
static DEVICE_ATTR_RW(period);
static DEVICE_ATTR_RW(duty_cycle);
static DEVICE_ATTR_RW(enable);
static DEVICE_ATTR_RW(polarity);
+static DEVICE_ATTR_RO(capture);
static struct attribute *pwm_attrs[] = {
&dev_attr_period.attr,
&dev_attr_duty_cycle.attr,
&dev_attr_enable.attr,
&dev_attr_polarity.attr,
+ &dev_attr_capture.attr,
NULL
};
ATTRIBUTE_GROUPS(pwm);
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 17018f3..f1bbae0 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -5,7 +5,9 @@
#include <linux/mutex.h>
#include <linux/of.h>
+struct pwm_capture;
struct seq_file;
+
struct pwm_chip;
/**
@@ -148,11 +150,100 @@
}
/**
+ * pwm_init_state() - prepare a new state to be applied with pwm_apply_state()
+ * @pwm: PWM device
+ * @state: state to fill with the prepared PWM state
+ *
+ * This functions prepares a state that can later be tweaked and applied
+ * to the PWM device with pwm_apply_state(). This is a convenient function
+ * that first retrieves the current PWM state and the replaces the period
+ * and polarity fields with the reference values defined in pwm->args.
+ * Once the function returns, you can adjust the ->enabled and ->duty_cycle
+ * fields according to your needs before calling pwm_apply_state().
+ *
+ * ->duty_cycle is initially set to zero to avoid cases where the current
+ * ->duty_cycle value exceed the pwm_args->period one, which would trigger
+ * an error if the user calls pwm_apply_state() without adjusting ->duty_cycle
+ * first.
+ */
+static inline void pwm_init_state(const struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct pwm_args args;
+
+ /* First get the current state. */
+ pwm_get_state(pwm, state);
+
+ /* Then fill it with the reference config */
+ pwm_get_args(pwm, &args);
+
+ state->period = args.period;
+ state->polarity = args.polarity;
+ state->duty_cycle = 0;
+}
+
+/**
+ * pwm_get_relative_duty_cycle() - Get a relative duty cycle value
+ * @state: PWM state to extract the duty cycle from
+ * @scale: target scale of the relative duty cycle
+ *
+ * This functions converts the absolute duty cycle stored in @state (expressed
+ * in nanosecond) into a value relative to the period.
+ *
+ * For example if you want to get the duty_cycle expressed in percent, call:
+ *
+ * pwm_get_state(pwm, &state);
+ * duty = pwm_get_relative_duty_cycle(&state, 100);
+ */
+static inline unsigned int
+pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale)
+{
+ if (!state->period)
+ return 0;
+
+ return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale,
+ state->period);
+}
+
+/**
+ * pwm_set_relative_duty_cycle() - Set a relative duty cycle value
+ * @state: PWM state to fill
+ * @duty_cycle: relative duty cycle value
+ * @scale: scale in which @duty_cycle is expressed
+ *
+ * This functions converts a relative into an absolute duty cycle (expressed
+ * in nanoseconds), and puts the result in state->duty_cycle.
+ *
+ * For example if you want to configure a 50% duty cycle, call:
+ *
+ * pwm_init_state(pwm, &state);
+ * pwm_set_relative_duty_cycle(&state, 50, 100);
+ * pwm_apply_state(pwm, &state);
+ *
+ * This functions returns -EINVAL if @duty_cycle and/or @scale are
+ * inconsistent (@scale == 0 or @duty_cycle > @scale).
+ */
+static inline int
+pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle,
+ unsigned int scale)
+{
+ if (!scale || duty_cycle > scale)
+ return -EINVAL;
+
+ state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)duty_cycle *
+ state->period,
+ scale);
+
+ return 0;
+}
+
+/**
* struct pwm_ops - PWM controller operations
* @request: optional hook for requesting a PWM
* @free: optional hook for freeing a PWM
* @config: configure duty cycles and period length for this PWM
* @set_polarity: configure the polarity of this PWM
+ * @capture: capture and report PWM signal
* @enable: enable PWM output toggling
* @disable: disable PWM output toggling
* @apply: atomically apply a new PWM config. The state argument
@@ -172,6 +263,8 @@
int duty_ns, int period_ns);
int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
enum pwm_polarity polarity);
+ int (*capture)(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_capture *result, unsigned long timeout);
int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
int (*apply)(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -212,6 +305,16 @@
bool can_sleep;
};
+/**
+ * struct pwm_capture - PWM capture data
+ * @period: period of the PWM signal (in nanoseconds)
+ * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
+ */
+struct pwm_capture {
+ unsigned int period;
+ unsigned int duty_cycle;
+};
+
#if IS_ENABLED(CONFIG_PWM)
/* PWM user APIs */
struct pwm_device *pwm_request(int pwm_id, const char *label);
@@ -235,6 +338,9 @@
if (!pwm)
return -EINVAL;
+ if (duty_ns < 0 || period_ns < 0)
+ return -EINVAL;
+
pwm_get_state(pwm, &state);
if (state.duty_cycle == duty_ns && state.period == period_ns)
return 0;
@@ -320,8 +426,9 @@
pwm_apply_state(pwm, &state);
}
-
/* PWM provider APIs */
+int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result,
+ unsigned long timeout);
int pwm_set_chip_data(struct pwm_device *pwm, void *data);
void *pwm_get_chip_data(struct pwm_device *pwm);
@@ -373,6 +480,13 @@
return -EINVAL;
}
+static inline int pwm_capture(struct pwm_device *pwm,
+ struct pwm_capture *result,
+ unsigned long timeout)
+{
+ return -EINVAL;
+}
+
static inline int pwm_set_polarity(struct pwm_device *pwm,
enum pwm_polarity polarity)
{
@@ -461,6 +575,8 @@
static inline void pwm_apply_args(struct pwm_device *pwm)
{
+ struct pwm_state state = { };
+
/*
* PWM users calling pwm_apply_args() expect to have a fresh config
* where the polarity and period are set according to pwm_args info.
@@ -473,18 +589,20 @@
* at startup (even if they are actually enabled), thus authorizing
* polarity setting.
*
- * Instead of setting ->enabled to false, we call pwm_disable()
- * before pwm_set_polarity() to ensure that everything is configured
- * as expected, and the PWM is really disabled when the user request
- * it.
+ * To fulfill this requirement, we apply a new state which disables
+ * the PWM device and set the reference period and polarity config.
*
* Note that PWM users requiring a smooth handover between the
* bootloader and the kernel (like critical regulators controlled by
* PWM devices) will have to switch to the atomic API and avoid calling
* pwm_apply_args().
*/
- pwm_disable(pwm);
- pwm_set_polarity(pwm, pwm->args.polarity);
+
+ state.enabled = false;
+ state.polarity = pwm->args.polarity;
+ state.period = pwm->args.period;
+
+ pwm_apply_state(pwm, &state);
}
struct pwm_lookup {