diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/core.c | 222 | ||||
| -rw-r--r-- | drivers/pwm/pwm-crc.c | 2 | ||||
| -rw-r--r-- | drivers/pwm/pwm-lpc18xx-sct.c | 2 | ||||
| -rw-r--r-- | drivers/pwm/pwm-omap-dmtimer.c | 2 | ||||
| -rw-r--r-- | drivers/pwm/pwm-rcar.c | 2 | ||||
| -rw-r--r-- | drivers/pwm/pwm-sun4i.c | 3 | ||||
| -rw-r--r-- | drivers/pwm/sysfs.c | 70 |
7 files changed, 194 insertions, 109 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index e4de9156974d..dba3843c53b8 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -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) + if (!pwm) 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) { @@ -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"); } } diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c index 7101c7020bf4..bd0ebd04856a 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 9861fed4e67d..19dc64cab2f0 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 b7e6ecba7d5c..3e95090cd7cf 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-rcar.c b/drivers/pwm/pwm-rcar.c index 7b8ac0678137..1c85ecc9e7ac 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 67af9f62361f..03a99a53c39e 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 9c90886f4123..d98599249a05 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; } + 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; |