for (i = 0; i < chip->npwm; i++) {
struct pwm_device *pwm = &chip->pwms[i];
+
radix_tree_delete(&pwm_tree, pwm->pwm);
}
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;
}
if (IS_ERR(pwm))
return pwm;
- pwm_set_period(pwm, args->args[1]);
+ pwm->args.period = args->args[1];
return 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
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);
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;
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);
}
unsigned int i;
int ret = 0;
+ pwmchip_sysfs_unexport_children(chip);
+
mutex_lock(&pwm_lock);
for (i = 0; i < chip->npwm; i++) {
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;
+ if (!memcmp(state, &pwm->state, sizeof(*state)))
+ return 0;
- pwm->duty_cycle = duty_ns;
- pwm->period = period_ns;
+ if (pwm->chip->ops->apply) {
+ err = pwm->chip->ops->apply(pwm->chip, pwm, state);
+ if (err)
+ return 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 (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;
+
+ pwm->state.duty_cycle = state->duty_cycle;
+ pwm->state.period = state->period;
+ }
+
+ 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);
+ }
+
+ pwm->state.enabled = state->enabled;
+ }
+ }
return 0;
}
-EXPORT_SYMBOL_GPL(pwm_config);
+EXPORT_SYMBOL_GPL(pwm_apply_state);
/**
- * pwm_set_polarity() - configure the polarity of a PWM signal
+ * pwm_capture() - capture and report 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.
+ * @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_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
+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->set_polarity)
+ if (!pwm->chip->ops->capture)
return -ENOSYS;
- mutex_lock(&pwm->lock);
-
- if (pwm_is_enabled(pwm)) {
- err = -EBUSY;
- goto unlock;
- }
-
- err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
- if (err)
- goto unlock;
-
- pwm->polarity = polarity;
+ mutex_lock(&pwm_lock);
+ err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout);
+ mutex_unlock(&pwm_lock);
-unlock:
- mutex_unlock(&pwm->lock);
return err;
}
-EXPORT_SYMBOL_GPL(pwm_set_polarity);
+EXPORT_SYMBOL_GPL(pwm_capture);
/**
- * 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)
{
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);
*/
bool pwm_can_sleep(struct pwm_device *pwm)
{
- return pwm->chip->can_sleep;
+ return true;
}
EXPORT_SYMBOL_GPL(pwm_can_sleep);
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");
}
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff