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Merge branch 'for-4.7/pwm-atomic' into for-next

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This commit is contained in:
Thierry Reding
2016-05-17 14:57:58 +02:00
parent d2a3f20684 23e3523f5d
commit 18c588786c
22 changed files with 591 additions and 224 deletions
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244
drivers/pwm/core.c
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@@ -227,6 +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
@@ -245,8 +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);
@@ -269,8 +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);
}
@@ -430,107 +447,138 @@ 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)
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;
return 0;
}
EXPORT_SYMBOL_GPL(pwm_config);
/**
* 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;
if (!pwm || !pwm->chip->ops)
return -EINVAL;
if (!pwm->chip->ops->set_polarity)
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;
unlock:
mutex_unlock(&pwm->lock);
return err;
}
EXPORT_SYMBOL_GPL(pwm_set_polarity);
/**
* pwm_enable() - start a PWM output toggling
* @pwm: PWM device
*
* Returns: 0 on success or a negative error code on failure.
*/
int pwm_enable(struct pwm_device *pwm)
{
int err = 0;
if (!pwm)
return -EINVAL;
mutex_lock(&pwm->lock);
if (!memcmp(state, &pwm->state, sizeof(*state)))
return 0;
if (!test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
err = pwm->chip->ops->enable(pwm->chip, pwm);
if (pwm->chip->ops->apply) {
err = pwm->chip->ops->apply(pwm->chip, pwm, state);
if (err)
clear_bit(PWMF_ENABLED, &pwm->flags);
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;
}
}
mutex_unlock(&pwm->lock);
return err;
return 0;
}
EXPORT_SYMBOL_GPL(pwm_enable);
EXPORT_SYMBOL_GPL(pwm_apply_state);
/**
* pwm_disable() - stop a PWM output toggling
* pwm_adjust_config() - adjust the current PWM config to the PWM arguments
* @pwm: PWM device
*
* 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.
*/
void pwm_disable(struct pwm_device *pwm)
int pwm_adjust_config(struct pwm_device *pwm)
{
if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags))
pwm->chip->ops->disable(pwm->chip, pwm);
struct pwm_state state;
struct pwm_args pargs;
pwm_get_args(pwm, &pargs);
pwm_get_state(pwm, &state);
/*
* 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;
return pwm_apply_state(pwm, &state);
}
/*
* 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;
do_div(dutycycle, state.period);
state.duty_cycle = dutycycle;
state.period = pargs.period;
}
/*
* 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)
{
@@ -621,13 +669,6 @@ struct pwm_device *of_pwm_get(struct device_node *np, const char *con_id)
pwm->label = con_id;
/*
* FIXME: This should be removed once all PWM users properly make use
* of struct pwm_args to initialize the PWM device. As long as this is
* here, the PWM state and hardware state can get out of sync.
*/
pwm_apply_args(pwm);
put:
of_node_put(args.np);
@@ -762,13 +803,6 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id)
pwm->args.period = chosen->period;
pwm->args.polarity = chosen->polarity;
/*
* FIXME: This should be removed once all PWM users properly make use
* of struct pwm_args to initialize the PWM device. As long as this is
* here, the PWM state and hardware state can get out of sync.
*/
pwm_apply_args(pwm);
out:
mutex_unlock(&pwm_lookup_lock);
return pwm;
@@ -915,15 +949,23 @@ 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");
}
}