diff options
Diffstat (limited to 'drivers/pwm/core.c')
| -rw-r--r-- | drivers/pwm/core.c | 1686 |
1 files changed, 1443 insertions, 243 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index d70f793ce4b3..4d842c692194 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -6,6 +6,8 @@ * Copyright (C) 2011-2012 Avionic Design GmbH */ +#define DEFAULT_SYMBOL_NAMESPACE "PWM" + #include <linux/acpi.h> #include <linux/module.h> #include <linux/idr.h> @@ -29,6 +31,454 @@ static DEFINE_MUTEX(pwm_lock); static DEFINE_IDR(pwm_chips); +static void pwmchip_lock(struct pwm_chip *chip) +{ + if (chip->atomic) + spin_lock(&chip->atomic_lock); + else + mutex_lock(&chip->nonatomic_lock); +} + +static void pwmchip_unlock(struct pwm_chip *chip) +{ + if (chip->atomic) + spin_unlock(&chip->atomic_lock); + else + mutex_unlock(&chip->nonatomic_lock); +} + +DEFINE_GUARD(pwmchip, struct pwm_chip *, pwmchip_lock(_T), pwmchip_unlock(_T)) + +static bool pwm_wf_valid(const struct pwm_waveform *wf) +{ + /* + * For now restrict waveforms to period_length_ns <= S64_MAX to provide + * some space for future extensions. One possibility is to simplify + * representing waveforms with inverted polarity using negative values + * somehow. + */ + if (wf->period_length_ns > S64_MAX) + return false; + + if (wf->duty_length_ns > wf->period_length_ns) + return false; + + /* + * .duty_offset_ns is supposed to be smaller than .period_length_ns, apart + * from the corner case .duty_offset_ns == 0 && .period_length_ns == 0. + */ + if (wf->duty_offset_ns && wf->duty_offset_ns >= wf->period_length_ns) + return false; + + return true; +} + +static void pwm_wf2state(const struct pwm_waveform *wf, struct pwm_state *state) +{ + if (wf->period_length_ns) { + if (wf->duty_length_ns + wf->duty_offset_ns < wf->period_length_ns) + *state = (struct pwm_state){ + .enabled = true, + .polarity = PWM_POLARITY_NORMAL, + .period = wf->period_length_ns, + .duty_cycle = wf->duty_length_ns, + }; + else + *state = (struct pwm_state){ + .enabled = true, + .polarity = PWM_POLARITY_INVERSED, + .period = wf->period_length_ns, + .duty_cycle = wf->period_length_ns - wf->duty_length_ns, + }; + } else { + *state = (struct pwm_state){ + .enabled = false, + }; + } +} + +static void pwm_state2wf(const struct pwm_state *state, struct pwm_waveform *wf) +{ + if (state->enabled) { + if (state->polarity == PWM_POLARITY_NORMAL) + *wf = (struct pwm_waveform){ + .period_length_ns = state->period, + .duty_length_ns = state->duty_cycle, + .duty_offset_ns = 0, + }; + else + *wf = (struct pwm_waveform){ + .period_length_ns = state->period, + .duty_length_ns = state->period - state->duty_cycle, + .duty_offset_ns = state->duty_cycle, + }; + } else { + *wf = (struct pwm_waveform){ + .period_length_ns = 0, + }; + } +} + +static int pwmwfcmp(const struct pwm_waveform *a, const struct pwm_waveform *b) +{ + if (a->period_length_ns > b->period_length_ns) + return 1; + + if (a->period_length_ns < b->period_length_ns) + return -1; + + if (a->duty_length_ns > b->duty_length_ns) + return 1; + + if (a->duty_length_ns < b->duty_length_ns) + return -1; + + if (a->duty_offset_ns > b->duty_offset_ns) + return 1; + + if (a->duty_offset_ns < b->duty_offset_ns) + return -1; + + return 0; +} + +static bool pwm_check_rounding(const struct pwm_waveform *wf, + const struct pwm_waveform *wf_rounded) +{ + if (!wf->period_length_ns) + return true; + + if (wf->period_length_ns < wf_rounded->period_length_ns) + return false; + + if (wf->duty_length_ns < wf_rounded->duty_length_ns) + return false; + + if (wf->duty_offset_ns < wf_rounded->duty_offset_ns) + return false; + + return true; +} + +static int __pwm_round_waveform_tohw(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_waveform *wf, void *wfhw) +{ + const struct pwm_ops *ops = chip->ops; + int ret; + + ret = ops->round_waveform_tohw(chip, pwm, wf, wfhw); + trace_pwm_round_waveform_tohw(pwm, wf, wfhw, ret); + + return ret; +} + +static int __pwm_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm, + const void *wfhw, struct pwm_waveform *wf) +{ + const struct pwm_ops *ops = chip->ops; + int ret; + + ret = ops->round_waveform_fromhw(chip, pwm, wfhw, wf); + trace_pwm_round_waveform_fromhw(pwm, wfhw, wf, ret); + + return ret; +} + +static int __pwm_read_waveform(struct pwm_chip *chip, struct pwm_device *pwm, void *wfhw) +{ + const struct pwm_ops *ops = chip->ops; + int ret; + + ret = ops->read_waveform(chip, pwm, wfhw); + trace_pwm_read_waveform(pwm, wfhw, ret); + + return ret; +} + +static int __pwm_write_waveform(struct pwm_chip *chip, struct pwm_device *pwm, const void *wfhw) +{ + const struct pwm_ops *ops = chip->ops; + int ret; + + ret = ops->write_waveform(chip, pwm, wfhw); + trace_pwm_write_waveform(pwm, wfhw, ret); + + return ret; +} + +#define WFHWSIZE 20 + +/** + * pwm_round_waveform_might_sleep - Query hardware capabilities + * Cannot be used in atomic context. + * @pwm: PWM device + * @wf: waveform to round and output parameter + * + * Typically a given waveform cannot be implemented exactly by hardware, e.g. + * because hardware only supports coarse period resolution or no duty_offset. + * This function returns the actually implemented waveform if you pass @wf to + * pwm_set_waveform_might_sleep() now. + * + * Note however that the world doesn't stop turning when you call it, so when + * doing:: + * + * pwm_round_waveform_might_sleep(mypwm, &wf); + * pwm_set_waveform_might_sleep(mypwm, &wf, true); + * + * the latter might fail, e.g. because an input clock changed its rate between + * these two calls and the waveform determined by + * pwm_round_waveform_might_sleep() cannot be implemented any more. + * + * Usually all values passed in @wf are rounded down to the nearest possible + * value (in the order period_length_ns, duty_length_ns and then + * duty_offset_ns). Only if this isn't possible, a value might grow. See the + * documentation for pwm_set_waveform_might_sleep() for a more formal + * description. + * + * Returns: 0 on success, 1 if at least one value had to be rounded up or a + * negative errno. + * Context: May sleep. + */ +int pwm_round_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf) +{ + struct pwm_chip *chip = pwm->chip; + const struct pwm_ops *ops = chip->ops; + struct pwm_waveform wf_req = *wf; + char wfhw[WFHWSIZE]; + int ret_tohw, ret_fromhw; + + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); + + if (!pwmchip_supports_waveform(chip)) + return -EOPNOTSUPP; + + if (!pwm_wf_valid(wf)) + return -EINVAL; + + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + + ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, wfhw); + if (ret_tohw < 0) + return ret_tohw; + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_tohw > 1) + dev_err(&chip->dev, "Unexpected return value from __pwm_round_waveform_tohw: requested %llu/%llu [+%llu], return value %d\n", + wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, ret_tohw); + + ret_fromhw = __pwm_round_waveform_fromhw(chip, pwm, wfhw, wf); + if (ret_fromhw < 0) + return ret_fromhw; + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_fromhw > 0) + dev_err(&chip->dev, "Unexpected return value from __pwm_round_waveform_fromhw: requested %llu/%llu [+%llu], return value %d\n", + wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, ret_tohw); + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && + (ret_tohw == 0) != pwm_check_rounding(&wf_req, wf)) + dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu], ret: %d\n", + wf_req.duty_length_ns, wf_req.period_length_ns, wf_req.duty_offset_ns, + wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns, ret_tohw); + + return ret_tohw; +} +EXPORT_SYMBOL_GPL(pwm_round_waveform_might_sleep); + +/** + * pwm_get_waveform_might_sleep - Query hardware about current configuration + * Cannot be used in atomic context. + * @pwm: PWM device + * @wf: output parameter + * + * Stores the current configuration of the PWM in @wf. Note this is the + * equivalent of pwm_get_state_hw() (and not pwm_get_state()) for pwm_waveform. + * + * Returns: 0 on success or a negative errno + * Context: May sleep. + */ +int pwm_get_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf) +{ + struct pwm_chip *chip = pwm->chip; + const struct pwm_ops *ops = chip->ops; + char wfhw[WFHWSIZE]; + int err; + + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); + + if (!pwmchip_supports_waveform(chip) || !ops->read_waveform) + return -EOPNOTSUPP; + + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + + err = __pwm_read_waveform(chip, pwm, &wfhw); + if (err) + return err; + + return __pwm_round_waveform_fromhw(chip, pwm, &wfhw, wf); +} +EXPORT_SYMBOL_GPL(pwm_get_waveform_might_sleep); + +/* Called with the pwmchip lock held */ +static int __pwm_set_waveform(struct pwm_device *pwm, + const struct pwm_waveform *wf, + bool exact) +{ + struct pwm_chip *chip = pwm->chip; + const struct pwm_ops *ops = chip->ops; + char wfhw[WFHWSIZE]; + struct pwm_waveform wf_rounded; + int err, ret_tohw; + + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); + + if (!pwmchip_supports_waveform(chip)) + return -EOPNOTSUPP; + + if (!pwm_wf_valid(wf)) + return -EINVAL; + + ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw); + if (ret_tohw < 0) + return ret_tohw; + + if ((IS_ENABLED(CONFIG_PWM_DEBUG) || exact) && wf->period_length_ns) { + err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded); + if (err) + return err; + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && (ret_tohw == 0) != pwm_check_rounding(wf, &wf_rounded)) + dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu], ret: %d\n", + wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns, + wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns, ret_tohw); + + if (exact && pwmwfcmp(wf, &wf_rounded)) { + dev_dbg(&chip->dev, "Requested no rounding, but %llu/%llu [+%llu] -> %llu/%llu [+%llu]\n", + wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns, + wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns); + + return 1; + } + } + + err = __pwm_write_waveform(chip, pwm, &wfhw); + if (err) + return err; + + /* update .state */ + pwm_wf2state(wf, &pwm->state); + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && ops->read_waveform && wf->period_length_ns) { + struct pwm_waveform wf_set; + + err = __pwm_read_waveform(chip, pwm, &wfhw); + if (err) + /* maybe ignore? */ + return err; + + err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_set); + if (err) + /* maybe ignore? */ + return err; + + if (pwmwfcmp(&wf_set, &wf_rounded) != 0) + dev_err(&chip->dev, + "Unexpected setting: requested %llu/%llu [+%llu], expected %llu/%llu [+%llu], set %llu/%llu [+%llu]\n", + wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns, + wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns, + wf_set.duty_length_ns, wf_set.period_length_ns, wf_set.duty_offset_ns); + } + + return ret_tohw; +} + +/** + * pwm_set_waveform_might_sleep - Apply a new waveform + * Cannot be used in atomic context. + * @pwm: PWM device + * @wf: The waveform to apply + * @exact: If true no rounding is allowed + * + * Typically a requested waveform cannot be implemented exactly, e.g. because + * you requested .period_length_ns = 100 ns, but the hardware can only set + * periods that are a multiple of 8.5 ns. With that hardware passing @exact = + * true results in pwm_set_waveform_might_sleep() failing and returning -EDOM. + * If @exact = false you get a period of 93.5 ns (i.e. the biggest period not + * bigger than the requested value). + * Note that even with @exact = true, some rounding by less than 1 ns is + * possible/needed. In the above example requesting .period_length_ns = 94 and + * @exact = true, you get the hardware configured with period = 93.5 ns. + * + * Let C be the set of possible hardware configurations for a given PWM device, + * consisting of tuples (p, d, o) where p is the period length, d is the duty + * length and o the duty offset. + * + * The following algorithm is implemented to pick the hardware setting + * (p, d, o) ∈ C for a given request (p', d', o') with @exact = false:: + * + * p = max( { ṗ | ∃ ḋ, ȯ : (ṗ, ḋ, ȯ) ∈ C ∧ ṗ ≤ p' } ∪ { min({ ṗ | ∃ ḋ, ȯ : (ṗ, ḋ, ȯ) ∈ C }) }) + * d = max( { ḋ | ∃ ȯ : (p, ḋ, ȯ) ∈ C ∧ ḋ ≤ d' } ∪ { min({ ḋ | ∃ ȯ : (p, ḋ, ȯ) ∈ C }) }) + * o = max( { ȯ | (p, d, ȯ) ∈ C ∧ ȯ ≤ o' } ∪ { min({ ȯ | (p, d, ȯ) ∈ C }) }) + * + * In words: The chosen period length is the maximal possible period length not + * bigger than the requested period length and if that doesn't exist, the + * minimal period length. The chosen duty length is the maximal possible duty + * length that is compatible with the chosen period length and isn't bigger than + * the requested duty length. Again if such a value doesn't exist, the minimal + * duty length compatible with the chosen period is picked. After that the duty + * offset compatible with the chosen period and duty length is chosen in the + * same way. + * + * Returns: 0 on success, -EDOM if setting failed due to the exact waveform not + * being possible (if @exact), or a different negative errno on failure. + * Context: May sleep. + */ +int pwm_set_waveform_might_sleep(struct pwm_device *pwm, + const struct pwm_waveform *wf, bool exact) +{ + struct pwm_chip *chip = pwm->chip; + int err; + + might_sleep(); + + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && chip->atomic) { + /* + * Catch any drivers that have been marked as atomic but + * that will sleep anyway. + */ + non_block_start(); + err = __pwm_set_waveform(pwm, wf, exact); + non_block_end(); + } else { + err = __pwm_set_waveform(pwm, wf, exact); + } + + /* + * map err == 1 to -EDOM for exact requests and 0 for !exact ones. Also + * make sure that -EDOM is only returned in exactly that case. Note that + * __pwm_set_waveform() should never return -EDOM which justifies the + * unlikely(). + */ + if (unlikely(err == -EDOM)) + err = -EINVAL; + else if (exact && err == 1) + err = -EDOM; + else if (err == 1) + err = 0; + + return err; +} +EXPORT_SYMBOL_GPL(pwm_set_waveform_might_sleep); + static void pwm_apply_debug(struct pwm_device *pwm, const struct pwm_state *state) { @@ -73,7 +523,7 @@ static void pwm_apply_debug(struct pwm_device *pwm, state->duty_cycle < state->period) dev_warn(pwmchip_parent(chip), ".apply ignored .polarity\n"); - if (state->enabled && + if (state->enabled && s2.enabled && last->polarity == state->polarity && last->period > s2.period && last->period <= state->period) @@ -81,7 +531,11 @@ static void pwm_apply_debug(struct pwm_device *pwm, ".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n", state->period, s2.period, last->period); - if (state->enabled && state->period < s2.period) + /* + * Rounding period up is fine only if duty_cycle is 0 then, because a + * flat line doesn't have a characteristic period. + */ + if (state->enabled && s2.enabled && state->period < s2.period && s2.duty_cycle) dev_warn(pwmchip_parent(chip), ".apply is supposed to round down period (requested: %llu, applied: %llu)\n", state->period, s2.period); @@ -97,7 +551,7 @@ static void pwm_apply_debug(struct pwm_device *pwm, s2.duty_cycle, s2.period, last->duty_cycle, last->period); - if (state->enabled && state->duty_cycle < s2.duty_cycle) + if (state->enabled && s2.enabled && state->duty_cycle < s2.duty_cycle) dev_warn(pwmchip_parent(chip), ".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n", state->duty_cycle, state->period, @@ -135,21 +589,53 @@ static void pwm_apply_debug(struct pwm_device *pwm, } } -/** - * __pwm_apply() - atomically apply a new state to a PWM device - * @pwm: PWM device - * @state: new state to apply - */ +static bool pwm_state_valid(const struct pwm_state *state) +{ + /* + * For a disabled state all other state description is irrelevant and + * and supposed to be ignored. So also ignore any strange values and + * consider the state ok. + */ + if (state->enabled) + return true; + + if (!state->period) + return false; + + if (state->duty_cycle > state->period) + return false; + + return true; +} + static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state) { struct pwm_chip *chip; + const struct pwm_ops *ops; int err; - if (!pwm || !state || !state->period || - state->duty_cycle > state->period) + if (!pwm || !state) + return -EINVAL; + + if (!pwm_state_valid(state)) { + /* + * Allow to transition from one invalid state to another. + * This ensures that you can e.g. change the polarity while + * the period is zero. (This happens on stm32 when the hardware + * is in its poweron default state.) This greatly simplifies + * working with the sysfs API where you can only change one + * parameter at a time. + */ + if (!pwm_state_valid(&pwm->state)) { + pwm->state = *state; + return 0; + } + return -EINVAL; + } chip = pwm->chip; + ops = chip->ops; if (state->period == pwm->state.period && state->duty_cycle == pwm->state.duty_cycle && @@ -158,18 +644,69 @@ static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state) state->usage_power == pwm->state.usage_power) return 0; - err = chip->ops->apply(chip, pwm, state); - trace_pwm_apply(pwm, state, err); - if (err) - return err; + if (pwmchip_supports_waveform(chip)) { + struct pwm_waveform wf; + char wfhw[WFHWSIZE]; - pwm->state = *state; + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); - /* - * only do this after pwm->state was applied as some - * implementations of .get_state depend on this - */ - pwm_apply_debug(pwm, state); + pwm_state2wf(state, &wf); + + /* + * The rounding is wrong here for states with inverted polarity. + * While .apply() rounds down duty_cycle (which represents the + * time from the start of the period to the inner edge), + * .round_waveform_tohw() rounds down the time the PWM is high. + * Can be fixed if the need arises, until reported otherwise + * let's assume that consumers don't care. + */ + + err = __pwm_round_waveform_tohw(chip, pwm, &wf, &wfhw); + if (err) { + if (err > 0) + /* + * This signals an invalid request, typically + * the requested period (or duty_offset) is + * smaller than possible with the hardware. + */ + return -EINVAL; + + return err; + } + + if (IS_ENABLED(CONFIG_PWM_DEBUG)) { + struct pwm_waveform wf_rounded; + + err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded); + if (err) + return err; + + if (!pwm_check_rounding(&wf, &wf_rounded)) + dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n", + wf.duty_length_ns, wf.period_length_ns, wf.duty_offset_ns, + wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns); + } + + err = __pwm_write_waveform(chip, pwm, &wfhw); + if (err) + return err; + + pwm->state = *state; + + } else { + err = ops->apply(chip, pwm, state); + trace_pwm_apply(pwm, state, err); + if (err) + return err; + + pwm->state = *state; + + /* + * only do this after pwm->state was applied as some + * implementations of .get_state() depend on this + */ + pwm_apply_debug(pwm, state); + } return 0; } @@ -179,10 +716,14 @@ static int __pwm_apply(struct pwm_device *pwm, const struct pwm_state *state) * Cannot be used in atomic context. * @pwm: PWM device * @state: new state to apply + * + * Returns: 0 on success, or a negative errno + * Context: May sleep. */ int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) { int err; + struct pwm_chip *chip = pwm->chip; /* * Some lowlevel driver's implementations of .apply() make use of @@ -193,7 +734,12 @@ int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) */ might_sleep(); - if (IS_ENABLED(CONFIG_PWM_DEBUG) && pwm->chip->atomic) { + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && chip->atomic) { /* * Catch any drivers that have been marked as atomic but * that will sleep anyway. @@ -214,23 +760,85 @@ EXPORT_SYMBOL_GPL(pwm_apply_might_sleep); * Not all PWM devices support this function, check with pwm_might_sleep(). * @pwm: PWM device * @state: new state to apply + * + * Returns: 0 on success, or a negative errno + * Context: Any */ int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state) { - WARN_ONCE(!pwm->chip->atomic, + struct pwm_chip *chip = pwm->chip; + + WARN_ONCE(!chip->atomic, "sleeping PWM driver used in atomic context\n"); + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + return __pwm_apply(pwm, state); } EXPORT_SYMBOL_GPL(pwm_apply_atomic); /** + * pwm_get_state_hw() - get the current PWM state from hardware + * @pwm: PWM device + * @state: state to fill with the current PWM state + * + * Similar to pwm_get_state() but reads the current PWM state from hardware + * instead of the requested state. + * + * Returns: 0 on success or a negative error code on failure. + * Context: May sleep. + */ +int pwm_get_state_hw(struct pwm_device *pwm, struct pwm_state *state) +{ + struct pwm_chip *chip = pwm->chip; + const struct pwm_ops *ops = chip->ops; + int ret = -EOPNOTSUPP; + + might_sleep(); + + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + + if (pwmchip_supports_waveform(chip) && ops->read_waveform) { + char wfhw[WFHWSIZE]; + struct pwm_waveform wf; + + BUG_ON(WFHWSIZE < ops->sizeof_wfhw); + + ret = __pwm_read_waveform(chip, pwm, &wfhw); + if (ret) + return ret; + + ret = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf); + if (ret) + return ret; + + pwm_wf2state(&wf, state); + + } else if (ops->get_state) { + ret = ops->get_state(chip, pwm, state); + trace_pwm_get(pwm, state, ret); + } + + return ret; +} +EXPORT_SYMBOL_GPL(pwm_get_state_hw); + +/** * 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. + * + * Returns: 0 on success or a negative error code on failure. + * Context: May sleep. */ int pwm_adjust_config(struct pwm_device *pwm) { @@ -288,24 +896,29 @@ EXPORT_SYMBOL_GPL(pwm_adjust_config); * * 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) +static int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, + unsigned long timeout) { - int err; - - if (!pwm || !pwm->chip->ops) - return -EINVAL; + struct pwm_chip *chip = pwm->chip; + const struct pwm_ops *ops = chip->ops; - if (!pwm->chip->ops->capture) + if (!ops->capture) return -ENOSYS; - mutex_lock(&pwm_lock); - err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout); - mutex_unlock(&pwm_lock); + /* + * Holding the pwm_lock is probably not needed. If you use pwm_capture() + * and you're interested to speed it up, please convince yourself it's + * really not needed, test and then suggest a patch on the mailing list. + */ + guard(mutex)(&pwm_lock); - return err; + guard(pwmchip)(chip); + + if (!chip->operational) + return -ENODEV; + + return ops->capture(chip, pwm, result, timeout); } -EXPORT_SYMBOL_GPL(pwm_capture); static struct pwm_chip *pwmchip_find_by_name(const char *name) { @@ -315,19 +928,13 @@ static struct pwm_chip *pwmchip_find_by_name(const char *name) if (!name) return NULL; - mutex_lock(&pwm_lock); + guard(mutex)(&pwm_lock); idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) { - const char *chip_name = dev_name(pwmchip_parent(chip)); - - if (chip_name && strcmp(chip_name, name) == 0) { - mutex_unlock(&pwm_lock); + if (device_match_name(pwmchip_parent(chip), name)) return chip; - } } - mutex_unlock(&pwm_lock); - return NULL; } @@ -340,18 +947,33 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) if (test_bit(PWMF_REQUESTED, &pwm->flags)) return -EBUSY; + /* + * This function is called while holding pwm_lock. As .operational only + * changes while holding this lock, checking it here without holding the + * chip lock is fine. + */ + if (!chip->operational) + return -ENODEV; + if (!try_module_get(chip->owner)) return -ENODEV; + if (!get_device(&chip->dev)) { + err = -ENODEV; + goto err_get_device; + } + if (ops->request) { err = ops->request(chip, pwm); if (err) { + put_device(&chip->dev); +err_get_device: module_put(chip->owner); return err; } } - if (ops->get_state) { + if (ops->read_waveform || ops->get_state) { /* * Zero-initialize state because most drivers are unaware of * .usage_power. The other members of state are supposed to be @@ -361,9 +983,7 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) */ struct pwm_state state = { 0, }; - err = ops->get_state(chip, pwm, &state); - trace_pwm_get(pwm, &state, err); - + err = pwm_get_state_hw(pwm, &state); if (!err) pwm->state = state; @@ -387,9 +1007,9 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) * chip. A negative error code is returned if the index is not valid for the * specified PWM chip or if the PWM device cannot be requested. */ -struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, - unsigned int index, - const char *label) +static struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, + unsigned int index, + const char *label) { struct pwm_device *pwm; int err; @@ -397,18 +1017,16 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, if (!chip || index >= chip->npwm) return ERR_PTR(-EINVAL); - mutex_lock(&pwm_lock); + guard(mutex)(&pwm_lock); + pwm = &chip->pwms[index]; err = pwm_device_request(pwm, label); if (err < 0) - pwm = ERR_PTR(err); + return ERR_PTR(err); - mutex_unlock(&pwm_lock); return pwm; } -EXPORT_SYMBOL_GPL(pwm_request_from_chip); - struct pwm_device * of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *args) @@ -434,16 +1052,32 @@ of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *arg } EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); +/* + * This callback is used for PXA PWM chips that only have a single PWM line. + * For such chips you could argue that passing the line number (i.e. the first + * parameter in the common case) is useless as it's always zero. So compared to + * the default xlate function of_pwm_xlate_with_flags() the first parameter is + * the default period and the second are flags. + * + * Note that if #pwm-cells = <3>, the semantic is the same as for + * of_pwm_xlate_with_flags() to allow converting the affected driver to + * #pwm-cells = <3> without breaking the legacy binding. + * + * Don't use for new drivers. + */ struct pwm_device * of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args) { struct pwm_device *pwm; + if (args->args_count >= 3) + return of_pwm_xlate_with_flags(chip, args); + pwm = pwm_request_from_chip(chip, 0, NULL); if (IS_ERR(pwm)) return pwm; - if (args->args_count > 1) + if (args->args_count > 0) pwm->args.period = args->args[0]; pwm->args.polarity = PWM_POLARITY_NORMAL; @@ -454,192 +1088,625 @@ of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args) } EXPORT_SYMBOL_GPL(of_pwm_single_xlate); -#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN +struct pwm_export { + struct device pwm_dev; + struct pwm_device *pwm; + struct mutex lock; + struct pwm_state suspend; +}; -static void *pwmchip_priv(struct pwm_chip *chip) +static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev) { - return (void *)chip + ALIGN(sizeof(*chip), PWMCHIP_ALIGN); + return container_of(pwmchip_dev, struct pwm_chip, dev); } -/* This is the counterpart to pwmchip_alloc() */ -void pwmchip_put(struct pwm_chip *chip) +static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev) { - kfree(chip); + return container_of(pwm_dev, struct pwm_export, pwm_dev); } -EXPORT_SYMBOL_GPL(pwmchip_put); -struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) +static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev) { - struct pwm_chip *chip; - size_t alloc_size; + struct pwm_export *export = pwmexport_from_dev(pwm_dev); - alloc_size = size_add(ALIGN(sizeof(*chip), PWMCHIP_ALIGN), sizeof_priv); + return export->pwm; +} - chip = kzalloc(alloc_size, GFP_KERNEL); - if (!chip) - return ERR_PTR(-ENOMEM); +static ssize_t period_show(struct device *pwm_dev, + struct device_attribute *attr, + char *buf) +{ + const struct pwm_device *pwm = pwm_from_dev(pwm_dev); + struct pwm_state state; - chip->dev = parent; - chip->npwm = npwm; + pwm_get_state(pwm, &state); - pwmchip_set_drvdata(chip, pwmchip_priv(chip)); + return sysfs_emit(buf, "%llu\n", state.period); +} - return chip; +static ssize_t period_store(struct device *pwm_dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pwm_export *export = pwmexport_from_dev(pwm_dev); + struct pwm_device *pwm = export->pwm; + struct pwm_state state; + u64 val; + int ret; + + ret = kstrtou64(buf, 0, &val); + if (ret) + return ret; + + guard(mutex)(&export->lock); + + pwm_get_state(pwm, &state); + state.period = val; + ret = pwm_apply_might_sleep(pwm, &state); + + return ret ? : size; } -EXPORT_SYMBOL_GPL(pwmchip_alloc); -static void devm_pwmchip_put(void *data) +static ssize_t duty_cycle_show(struct device *pwm_dev, + struct device_attribute *attr, + char *buf) { - struct pwm_chip *chip = data; + const struct pwm_device *pwm = pwm_from_dev(pwm_dev); + struct pwm_state state; - pwmchip_put(chip); + pwm_get_state(pwm, &state); + + return sysfs_emit(buf, "%llu\n", state.duty_cycle); } -struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) +static ssize_t duty_cycle_store(struct device *pwm_dev, + struct device_attribute *attr, + const char *buf, size_t size) { - struct pwm_chip *chip; + struct pwm_export *export = pwmexport_from_dev(pwm_dev); + struct pwm_device *pwm = export->pwm; + struct pwm_state state; + u64 val; int ret; - chip = pwmchip_alloc(parent, npwm, sizeof_priv); - if (IS_ERR(chip)) - return chip; - - ret = devm_add_action_or_reset(parent, devm_pwmchip_put, chip); + ret = kstrtou64(buf, 0, &val); if (ret) - return ERR_PTR(ret); + return ret; - return chip; + guard(mutex)(&export->lock); + + pwm_get_state(pwm, &state); + state.duty_cycle = val; + ret = pwm_apply_might_sleep(pwm, &state); + + return ret ? : size; } -EXPORT_SYMBOL_GPL(devm_pwmchip_alloc); -static void of_pwmchip_add(struct pwm_chip *chip) +static ssize_t enable_show(struct device *pwm_dev, + struct device_attribute *attr, + char *buf) { - if (!pwmchip_parent(chip) || !pwmchip_parent(chip)->of_node) - return; + const struct pwm_device *pwm = pwm_from_dev(pwm_dev); + struct pwm_state state; - if (!chip->of_xlate) - chip->of_xlate = of_pwm_xlate_with_flags; + pwm_get_state(pwm, &state); - of_node_get(pwmchip_parent(chip)->of_node); + return sysfs_emit(buf, "%d\n", state.enabled); } -static void of_pwmchip_remove(struct pwm_chip *chip) +static ssize_t enable_store(struct device *pwm_dev, + struct device_attribute *attr, + const char *buf, size_t size) { - if (pwmchip_parent(chip)) - of_node_put(pwmchip_parent(chip)->of_node); + struct pwm_export *export = pwmexport_from_dev(pwm_dev); + struct pwm_device *pwm = export->pwm; + struct pwm_state state; + int val, ret; + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + guard(mutex)(&export->lock); + + pwm_get_state(pwm, &state); + + switch (val) { + case 0: + state.enabled = false; + break; + case 1: + state.enabled = true; + break; + default: + return -EINVAL; + } + + ret = pwm_apply_might_sleep(pwm, &state); + + return ret ? : size; } -static bool pwm_ops_check(const struct pwm_chip *chip) +static ssize_t polarity_show(struct device *pwm_dev, + struct device_attribute *attr, + char *buf) { - const struct pwm_ops *ops = chip->ops; + const struct pwm_device *pwm = pwm_from_dev(pwm_dev); + const char *polarity = "unknown"; + struct pwm_state state; - if (!ops->apply) - return false; + pwm_get_state(pwm, &state); - if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state) - dev_warn(pwmchip_parent(chip), - "Please implement the .get_state() callback\n"); + switch (state.polarity) { + case PWM_POLARITY_NORMAL: + polarity = "normal"; + break; - return true; + case PWM_POLARITY_INVERSED: + polarity = "inversed"; + break; + } + + return sysfs_emit(buf, "%s\n", polarity); } -/** - * __pwmchip_add() - register a new PWM chip - * @chip: the PWM chip to add - * @owner: reference to the module providing the chip. - * - * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the - * pwmchip_add wrapper to do this right. - * - * Returns: 0 on success or a negative error code on failure. - */ -int __pwmchip_add(struct pwm_chip *chip, struct module *owner) +static ssize_t polarity_store(struct device *pwm_dev, + struct device_attribute *attr, + const char *buf, size_t size) { - unsigned int i; + struct pwm_export *export = pwmexport_from_dev(pwm_dev); + struct pwm_device *pwm = export->pwm; + enum pwm_polarity polarity; + struct pwm_state state; int ret; - if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm) + if (sysfs_streq(buf, "normal")) + polarity = PWM_POLARITY_NORMAL; + else if (sysfs_streq(buf, "inversed")) + polarity = PWM_POLARITY_INVERSED; + else return -EINVAL; - if (!pwm_ops_check(chip)) - return -EINVAL; + guard(mutex)(&export->lock); - chip->owner = owner; + pwm_get_state(pwm, &state); + state.polarity = polarity; + ret = pwm_apply_might_sleep(pwm, &state); + + return ret ? : size; +} + +static ssize_t capture_show(struct device *pwm_dev, + struct device_attribute *attr, + char *buf) +{ + struct pwm_device *pwm = pwm_from_dev(pwm_dev); + struct pwm_capture result; + int ret; + + ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ)); + if (ret) + return ret; + + return sysfs_emit(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); + +static void pwm_export_release(struct device *pwm_dev) +{ + struct pwm_export *export = pwmexport_from_dev(pwm_dev); + + kfree(export); +} + +static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm) +{ + struct pwm_export *export; + char *pwm_prop[2]; + int ret; + + if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags)) + return -EBUSY; - chip->pwms = kcalloc(chip->npwm, sizeof(*chip->pwms), GFP_KERNEL); - if (!chip->pwms) + export = kzalloc(sizeof(*export), GFP_KERNEL); + if (!export) { + clear_bit(PWMF_EXPORTED, &pwm->flags); return -ENOMEM; + } - mutex_lock(&pwm_lock); + export->pwm = pwm; + mutex_init(&export->lock); - ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL); - if (ret < 0) { - mutex_unlock(&pwm_lock); - kfree(chip->pwms); + export->pwm_dev.release = pwm_export_release; + export->pwm_dev.parent = pwmchip_dev; + export->pwm_dev.devt = MKDEV(0, 0); + export->pwm_dev.groups = pwm_groups; + dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm); + + ret = device_register(&export->pwm_dev); + if (ret) { + clear_bit(PWMF_EXPORTED, &pwm->flags); + put_device(&export->pwm_dev); + export = NULL; return ret; } + pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm); + pwm_prop[1] = NULL; + kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop); + kfree(pwm_prop[0]); - chip->id = ret; + return 0; +} + +static int pwm_unexport_match(struct device *pwm_dev, const void *data) +{ + return pwm_from_dev(pwm_dev) == data; +} + +static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm) +{ + struct device *pwm_dev; + char *pwm_prop[2]; + + if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags)) + return -ENODEV; + + pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match); + if (!pwm_dev) + return -ENODEV; + + pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm); + pwm_prop[1] = NULL; + kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop); + kfree(pwm_prop[0]); + + /* for device_find_child() */ + put_device(pwm_dev); + device_unregister(pwm_dev); + pwm_put(pwm); + + return 0; +} + +static ssize_t export_store(struct device *pwmchip_dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); + struct pwm_device *pwm; + unsigned int hwpwm; + int ret; + + ret = kstrtouint(buf, 0, &hwpwm); + if (ret < 0) + return ret; + + if (hwpwm >= chip->npwm) + return -ENODEV; + + pwm = pwm_request_from_chip(chip, hwpwm, "sysfs"); + if (IS_ERR(pwm)) + return PTR_ERR(pwm); + + ret = pwm_export_child(pwmchip_dev, pwm); + if (ret < 0) + pwm_put(pwm); + + return ret ? : len; +} +static DEVICE_ATTR_WO(export); + +static ssize_t unexport_store(struct device *pwmchip_dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); + unsigned int hwpwm; + int ret; + + ret = kstrtouint(buf, 0, &hwpwm); + if (ret < 0) + return ret; + + if (hwpwm >= chip->npwm) + return -ENODEV; + + ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]); + + return ret ? : len; +} +static DEVICE_ATTR_WO(unexport); + +static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr, + char *buf) +{ + const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); + + return sysfs_emit(buf, "%u\n", chip->npwm); +} +static DEVICE_ATTR_RO(npwm); + +static struct attribute *pwm_chip_attrs[] = { + &dev_attr_export.attr, + &dev_attr_unexport.attr, + &dev_attr_npwm.attr, + NULL, +}; +ATTRIBUTE_GROUPS(pwm_chip); + +/* takes export->lock on success */ +static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev, + struct pwm_device *pwm, + struct pwm_state *state) +{ + struct device *pwm_dev; + struct pwm_export *export; + + if (!test_bit(PWMF_EXPORTED, &pwm->flags)) + return NULL; + + pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match); + if (!pwm_dev) + return NULL; + + export = pwmexport_from_dev(pwm_dev); + put_device(pwm_dev); /* for device_find_child() */ + + mutex_lock(&export->lock); + pwm_get_state(pwm, state); + + return export; +} + +static int pwm_class_apply_state(struct pwm_export *export, + struct pwm_device *pwm, + struct pwm_state *state) +{ + int ret = pwm_apply_might_sleep(pwm, state); + + /* release lock taken in pwm_class_get_state */ + mutex_unlock(&export->lock); + + return ret; +} + +static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm) +{ + struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); + unsigned int i; + int ret = 0; + + for (i = 0; i < npwm; i++) { + struct pwm_device *pwm = &chip->pwms[i]; + struct pwm_state state; + struct pwm_export *export; + + export = pwm_class_get_state(pwmchip_dev, pwm, &state); + if (!export) + continue; + + /* If pwmchip was not enabled before suspend, do nothing. */ + if (!export->suspend.enabled) { + /* release lock taken in pwm_class_get_state */ + mutex_unlock(&export->lock); + continue; + } + + state.enabled = export->suspend.enabled; + ret = pwm_class_apply_state(export, pwm, &state); + if (ret < 0) + break; + } + + return ret; +} + +static int pwm_class_suspend(struct device *pwmchip_dev) +{ + struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); + unsigned int i; + int ret = 0; for (i = 0; i < chip->npwm; i++) { struct pwm_device *pwm = &chip->pwms[i]; + struct pwm_state state; + struct pwm_export *export; - pwm->chip = chip; - pwm->hwpwm = i; + export = pwm_class_get_state(pwmchip_dev, pwm, &state); + if (!export) + continue; + + /* + * If pwmchip was not enabled before suspend, save + * state for resume time and do nothing else. + */ + export->suspend = state; + if (!state.enabled) { + /* release lock taken in pwm_class_get_state */ + mutex_unlock(&export->lock); + continue; + } + + state.enabled = false; + ret = pwm_class_apply_state(export, pwm, &state); + if (ret < 0) { + /* + * roll back the PWM devices that were disabled by + * this suspend function. + */ + pwm_class_resume_npwm(pwmchip_dev, i); + break; + } } - mutex_unlock(&pwm_lock); + return ret; +} - if (IS_ENABLED(CONFIG_OF)) - of_pwmchip_add(chip); +static int pwm_class_resume(struct device *pwmchip_dev) +{ + struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); - pwmchip_sysfs_export(chip); + return pwm_class_resume_npwm(pwmchip_dev, chip->npwm); +} - return 0; +static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume); + +static struct class pwm_class = { + .name = "pwm", + .dev_groups = pwm_chip_groups, + .pm = pm_sleep_ptr(&pwm_class_pm_ops), +}; + +static void pwmchip_sysfs_unexport(struct pwm_chip *chip) +{ + unsigned int i; + + for (i = 0; i < chip->npwm; i++) { + struct pwm_device *pwm = &chip->pwms[i]; + + if (test_bit(PWMF_EXPORTED, &pwm->flags)) + pwm_unexport_child(&chip->dev, pwm); + } } -EXPORT_SYMBOL_GPL(__pwmchip_add); -/** - * pwmchip_remove() - remove a PWM chip - * @chip: the PWM chip to remove - * - * Removes a PWM chip. - */ -void pwmchip_remove(struct pwm_chip *chip) +#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN + +static void *pwmchip_priv(struct pwm_chip *chip) { - pwmchip_sysfs_unexport(chip); + return (void *)chip + ALIGN(struct_size(chip, pwms, chip->npwm), PWMCHIP_ALIGN); +} - if (IS_ENABLED(CONFIG_OF)) - of_pwmchip_remove(chip); +/* This is the counterpart to pwmchip_alloc() */ +void pwmchip_put(struct pwm_chip *chip) +{ + put_device(&chip->dev); +} +EXPORT_SYMBOL_GPL(pwmchip_put); - mutex_lock(&pwm_lock); +static void pwmchip_release(struct device *pwmchip_dev) +{ + struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); - idr_remove(&pwm_chips, chip->id); + kfree(chip); +} - mutex_unlock(&pwm_lock); +struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) +{ + struct pwm_chip *chip; + struct device *pwmchip_dev; + size_t alloc_size; + unsigned int i; + + alloc_size = size_add(ALIGN(struct_size(chip, pwms, npwm), PWMCHIP_ALIGN), + sizeof_priv); + + chip = kzalloc(alloc_size, GFP_KERNEL); + if (!chip) + return ERR_PTR(-ENOMEM); + + chip->npwm = npwm; + chip->uses_pwmchip_alloc = true; + chip->operational = false; + + pwmchip_dev = &chip->dev; + device_initialize(pwmchip_dev); + pwmchip_dev->class = &pwm_class; + pwmchip_dev->parent = parent; + pwmchip_dev->release = pwmchip_release; + + pwmchip_set_drvdata(chip, pwmchip_priv(chip)); + + for (i = 0; i < chip->npwm; i++) { + struct pwm_device *pwm = &chip->pwms[i]; + pwm->chip = chip; + pwm->hwpwm = i; + } - kfree(chip->pwms); + return chip; } -EXPORT_SYMBOL_GPL(pwmchip_remove); +EXPORT_SYMBOL_GPL(pwmchip_alloc); -static void devm_pwmchip_remove(void *data) +static void devm_pwmchip_put(void *data) { struct pwm_chip *chip = data; - pwmchip_remove(chip); + pwmchip_put(chip); } -int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner) +struct pwm_chip *devm_pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) { + struct pwm_chip *chip; int ret; - ret = __pwmchip_add(chip, owner); + chip = pwmchip_alloc(parent, npwm, sizeof_priv); + if (IS_ERR(chip)) + return chip; + + ret = devm_add_action_or_reset(parent, devm_pwmchip_put, chip); if (ret) - return ret; + return ERR_PTR(ret); - return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip); + return chip; +} +EXPORT_SYMBOL_GPL(devm_pwmchip_alloc); + +static void of_pwmchip_add(struct pwm_chip *chip) +{ + if (!pwmchip_parent(chip) || !pwmchip_parent(chip)->of_node) + return; + + if (!chip->of_xlate) + chip->of_xlate = of_pwm_xlate_with_flags; + + of_node_get(pwmchip_parent(chip)->of_node); +} + +static void of_pwmchip_remove(struct pwm_chip *chip) +{ + if (pwmchip_parent(chip)) + of_node_put(pwmchip_parent(chip)->of_node); +} + +static bool pwm_ops_check(const struct pwm_chip *chip) +{ + const struct pwm_ops *ops = chip->ops; + + if (ops->write_waveform) { + if (!ops->round_waveform_tohw || + !ops->round_waveform_fromhw || + !ops->write_waveform) + return false; + + if (WFHWSIZE < ops->sizeof_wfhw) { + dev_warn(pwmchip_parent(chip), "WFHWSIZE < %zu\n", ops->sizeof_wfhw); + return false; + } + } else { + if (!ops->apply) + return false; + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state) + dev_warn(pwmchip_parent(chip), + "Please implement the .get_state() callback\n"); + } + + return true; } -EXPORT_SYMBOL_GPL(__devm_pwmchip_add); static struct device_link *pwm_device_link_add(struct device *dev, struct pwm_device *pwm) @@ -672,15 +1739,11 @@ static struct pwm_chip *fwnode_to_pwmchip(struct fwnode_handle *fwnode) struct pwm_chip *chip; unsigned long id, tmp; - mutex_lock(&pwm_lock); + guard(mutex)(&pwm_lock); idr_for_each_entry_ul(&pwm_chips, chip, tmp, id) - if (pwmchip_parent(chip) && device_match_fwnode(pwmchip_parent(chip), fwnode)) { - mutex_unlock(&pwm_lock); + if (pwmchip_parent(chip) && device_match_fwnode(pwmchip_parent(chip), fwnode)) return chip; - } - - mutex_unlock(&pwm_lock); return ERR_PTR(-EPROBE_DEFER); } @@ -721,8 +1784,7 @@ static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np, return ERR_PTR(index); } - err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, - &args); + err = of_parse_phandle_with_args_map(np, "pwms", "pwm", index, &args); if (err) { pr_err("%s(): can't parse \"pwms\" property\n", __func__); return ERR_PTR(err); @@ -823,40 +1885,6 @@ static DEFINE_MUTEX(pwm_lookup_lock); static LIST_HEAD(pwm_lookup_list); /** - * pwm_add_table() - register PWM device consumers - * @table: array of consumers to register - * @num: number of consumers in table - */ -void pwm_add_table(struct pwm_lookup *table, size_t num) -{ - mutex_lock(&pwm_lookup_lock); - - while (num--) { - list_add_tail(&table->list, &pwm_lookup_list); - table++; - } - - mutex_unlock(&pwm_lookup_lock); -} - -/** - * pwm_remove_table() - unregister PWM device consumers - * @table: array of consumers to unregister - * @num: number of consumers in table - */ -void pwm_remove_table(struct pwm_lookup *table, size_t num) -{ - mutex_lock(&pwm_lookup_lock); - - while (num--) { - list_del(&table->list); - table++; - } - - mutex_unlock(&pwm_lookup_lock); -} - -/** * pwm_get() - look up and request a PWM device * @dev: device for PWM consumer * @con_id: consumer name @@ -914,36 +1942,33 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id) * Then we take the most specific entry - with the following order * of precedence: dev+con > dev only > con only. */ - mutex_lock(&pwm_lookup_lock); - - list_for_each_entry(p, &pwm_lookup_list, list) { - match = 0; + scoped_guard(mutex, &pwm_lookup_lock) + list_for_each_entry(p, &pwm_lookup_list, list) { + match = 0; - if (p->dev_id) { - if (!dev_id || strcmp(p->dev_id, dev_id)) - continue; + if (p->dev_id) { + if (!dev_id || strcmp(p->dev_id, dev_id)) + continue; - match += 2; - } + match += 2; + } - if (p->con_id) { - if (!con_id || strcmp(p->con_id, con_id)) - continue; + if (p->con_id) { + if (!con_id || strcmp(p->con_id, con_id)) + continue; - match += 1; - } + match += 1; + } - if (match > best) { - chosen = p; + if (match > best) { + chosen = p; - if (match != 3) - best = match; - else - break; + if (match != 3) + best = match; + else + break; + } } - } - - mutex_unlock(&pwm_lookup_lock); if (!chosen) return ERR_PTR(-ENODEV); @@ -988,24 +2013,33 @@ EXPORT_SYMBOL_GPL(pwm_get); */ void pwm_put(struct pwm_device *pwm) { + struct pwm_chip *chip; + if (!pwm) return; - mutex_lock(&pwm_lock); + chip = pwm->chip; - if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { + guard(mutex)(&pwm_lock); + + /* + * Trigger a warning if a consumer called pwm_put() twice. + * If the chip isn't operational, PWMF_REQUESTED was already cleared in + * pwmchip_remove(). So don't warn in this case. + */ + if (chip->operational && !test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { pr_warn("PWM device already freed\n"); - goto out; + return; } - if (pwm->chip->ops->free) + if (chip->operational && chip->ops->free) pwm->chip->ops->free(pwm->chip, pwm); pwm->label = NULL; - module_put(pwm->chip->owner); -out: - mutex_unlock(&pwm_lock); + put_device(&chip->dev); + + module_put(chip->owner); } EXPORT_SYMBOL_GPL(pwm_put); @@ -1076,32 +2110,190 @@ struct pwm_device *devm_fwnode_pwm_get(struct device *dev, } EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get); -#ifdef CONFIG_DEBUG_FS +/** + * __pwmchip_add() - register a new PWM chip + * @chip: the PWM chip to add + * @owner: reference to the module providing the chip. + * + * Register a new PWM chip. @owner is supposed to be THIS_MODULE, use the + * pwmchip_add wrapper to do this right. + * + * Returns: 0 on success or a negative error code on failure. + */ +int __pwmchip_add(struct pwm_chip *chip, struct module *owner) +{ + int ret; + + if (!chip || !pwmchip_parent(chip) || !chip->ops || !chip->npwm) + return -EINVAL; + + /* + * a struct pwm_chip must be allocated using (devm_)pwmchip_alloc, + * otherwise the embedded struct device might disappear too early + * resulting in memory corruption. + * Catch drivers that were not converted appropriately. + */ + if (!chip->uses_pwmchip_alloc) + return -EINVAL; + + if (!pwm_ops_check(chip)) + return -EINVAL; + + chip->owner = owner; + + if (chip->atomic) + spin_lock_init(&chip->atomic_lock); + else + mutex_init(&chip->nonatomic_lock); + + guard(mutex)(&pwm_lock); + + ret = idr_alloc(&pwm_chips, chip, 0, 0, GFP_KERNEL); + if (ret < 0) + return ret; + + chip->id = ret; + + dev_set_name(&chip->dev, "pwmchip%u", chip->id); + + if (IS_ENABLED(CONFIG_OF)) + of_pwmchip_add(chip); + + scoped_guard(pwmchip, chip) + chip->operational = true; + + ret = device_add(&chip->dev); + if (ret) + goto err_device_add; + + return 0; + +err_device_add: + scoped_guard(pwmchip, chip) + chip->operational = false; + + if (IS_ENABLED(CONFIG_OF)) + of_pwmchip_remove(chip); + + idr_remove(&pwm_chips, chip->id); + + return ret; +} +EXPORT_SYMBOL_GPL(__pwmchip_add); + +/** + * pwmchip_remove() - remove a PWM chip + * @chip: the PWM chip to remove + * + * Removes a PWM chip. + */ +void pwmchip_remove(struct pwm_chip *chip) +{ + pwmchip_sysfs_unexport(chip); + + scoped_guard(mutex, &pwm_lock) { + unsigned int i; + + scoped_guard(pwmchip, chip) + chip->operational = false; + + for (i = 0; i < chip->npwm; ++i) { + struct pwm_device *pwm = &chip->pwms[i]; + + if (test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { + dev_warn(&chip->dev, "Freeing requested PWM #%u\n", i); + if (pwm->chip->ops->free) + pwm->chip->ops->free(pwm->chip, pwm); + } + } + + if (IS_ENABLED(CONFIG_OF)) + of_pwmchip_remove(chip); + + idr_remove(&pwm_chips, chip->id); + } + + device_del(&chip->dev); +} +EXPORT_SYMBOL_GPL(pwmchip_remove); + +static void devm_pwmchip_remove(void *data) +{ + struct pwm_chip *chip = data; + + pwmchip_remove(chip); +} + +int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner) +{ + int ret; + + ret = __pwmchip_add(chip, owner); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, devm_pwmchip_remove, chip); +} +EXPORT_SYMBOL_GPL(__devm_pwmchip_add); + +/** + * pwm_add_table() - register PWM device consumers + * @table: array of consumers to register + * @num: number of consumers in table + */ +void pwm_add_table(struct pwm_lookup *table, size_t num) +{ + guard(mutex)(&pwm_lookup_lock); + + while (num--) { + list_add_tail(&table->list, &pwm_lookup_list); + table++; + } +} + +/** + * pwm_remove_table() - unregister PWM device consumers + * @table: array of consumers to unregister + * @num: number of consumers in table + */ +void pwm_remove_table(struct pwm_lookup *table, size_t num) +{ + guard(mutex)(&pwm_lookup_lock); + + while (num--) { + list_del(&table->list); + table++; + } +} + static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) { unsigned int i; for (i = 0; i < chip->npwm; i++) { struct pwm_device *pwm = &chip->pwms[i]; - struct pwm_state state; + struct pwm_state state, hwstate; pwm_get_state(pwm, &state); + pwm_get_state_hw(pwm, &hwstate); seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); if (test_bit(PWMF_REQUESTED, &pwm->flags)) seq_puts(s, " requested"); - if (state.enabled) - seq_puts(s, " enabled"); + seq_puts(s, "\n"); - seq_printf(s, " period: %llu ns", state.period); - seq_printf(s, " duty: %llu ns", state.duty_cycle); - seq_printf(s, " polarity: %s", + seq_printf(s, " requested configuration: %3sabled, %llu/%llu ns, %s polarity", + state.enabled ? "en" : "dis", state.duty_cycle, state.period, state.polarity ? "inverse" : "normal"); - if (state.usage_power) - seq_puts(s, " usage_power"); + seq_puts(s, ", usage_power"); + seq_puts(s, "\n"); + + seq_printf(s, " actual configuration: %3sabled, %llu/%llu ns, %s polarity", + hwstate.enabled ? "en" : "dis", hwstate.duty_cycle, hwstate.period, + hwstate.polarity ? "inverse" : "normal"); seq_puts(s, "\n"); } @@ -1161,11 +2353,19 @@ static const struct seq_operations pwm_debugfs_sops = { DEFINE_SEQ_ATTRIBUTE(pwm_debugfs); -static int __init pwm_debugfs_init(void) +static int __init pwm_init(void) { - debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops); + int ret; + + ret = class_register(&pwm_class); + if (ret) { + pr_err("Failed to initialize PWM class (%pe)\n", ERR_PTR(ret)); + return ret; + } + + if (IS_ENABLED(CONFIG_DEBUG_FS)) + debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops); return 0; } -subsys_initcall(pwm_debugfs_init); -#endif /* CONFIG_DEBUG_FS */ +subsys_initcall(pwm_init); |