From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Wed, 1 Jul 2015 10:21:57 +0200 Subject: [RFC PATCH 11/15] pwm: add the core infrastructure to allow atomic update In-Reply-To: <1435738921-25027-1-git-send-email-boris.brezillon@free-electrons.com> References: <1435738921-25027-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <1435738921-25027-12-git-send-email-boris.brezillon@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Add an ->apply() method to the pwm_ops struct to allow PWM drivers to implement atomic update. This method will be prefered over the ->enable(), ->disable() and ->config() methods if available. Add the pwm_get_state(), pwm_get_default_state() and pwm_apply_state() functions for PWM users to be able to use the atomic update feature. Note that the pwm_apply_state() does not guarantee the atomicity of the update operation, it all depends on the availability and implementation of the ->apply() method. Signed-off-by: Boris Brezillon --- drivers/pwm/core.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++------ include/linux/pwm.h | 26 +++++++++++++ 2 files changed, 124 insertions(+), 12 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 30631f5..6dafd8e 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -238,8 +238,9 @@ 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->ops->apply && + (!chip->ops->config || !chip->ops->enable || + !chip->ops->disable)) || !chip->npwm) return -EINVAL; mutex_lock(&pwm_lock); @@ -430,7 +431,17 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) 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 (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.period = period_ns; + state.duty_cycle = duty_ns; + + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { + err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); + } + if (err) return err; @@ -455,6 +466,17 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (!pwm || !pwm->chip->ops) return -EINVAL; + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.polarity = polarity; + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + if (!err) + pwm->state.polarity = polarity; + + return err; + } + if (!pwm->chip->ops->set_polarity) return -ENOSYS; @@ -477,17 +499,27 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity); */ int pwm_enable(struct pwm_device *pwm) { - if (pwm && !pwm_is_enabled(pwm)) { - int err; + int err; - err = pwm->chip->ops->enable(pwm->chip, pwm); - if (!err) - pwm->state.enabled = true; + if (!pwm) + return -EINVAL; - return err; + if (pwm_is_enabled(pwm)) + return 0; + + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.enabled = true; + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { + err = pwm->chip->ops->enable(pwm->chip, pwm); } - return pwm ? 0 : -EINVAL; + if (!err) + pwm->state.enabled = true; + + return err; } EXPORT_SYMBOL_GPL(pwm_enable); @@ -497,13 +529,67 @@ EXPORT_SYMBOL_GPL(pwm_enable); */ void pwm_disable(struct pwm_device *pwm) { - if (pwm && pwm_is_enabled(pwm)) { + if (!pwm || !pwm_is_enabled(pwm)) + return; + + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.enabled = false; + pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { pwm->chip->ops->disable(pwm->chip, pwm); - pwm->state.enabled = false; } + + pwm->state.enabled = false; } EXPORT_SYMBOL_GPL(pwm_disable); +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) +{ + int err = 0; + + if (!pwm) + return -EINVAL; + + if (!memcmp(state, &pwm->state, sizeof(*state))) + return 0; + + if (pwm->chip->ops->apply) { + err = pwm->chip->ops->apply(pwm->chip, pwm, state); + if (!err) + pwm->state = *state; + } else { + /* + * FIXME: restore the initial state in case of error. + */ + if (state->polarity != pwm->state.polarity) { + pwm_disable(pwm); + err = pwm_set_polarity(pwm, state->polarity); + if (err) + goto out; + } + + if (state->period != pwm->state.period || + state->duty_cycle != pwm->state.duty_cycle) { + err = pwm_config(pwm, state->period, state->duty_cycle); + if (err) + goto out; + } + + if (state->enabled != pwm->state.enabled) { + if (state->enabled) + err = pwm_enable(pwm); + else + pwm_disable(pwm); + } + } + +out: + return err; +} +EXPORT_SYMBOL_GPL(pwm_apply_state); + static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) { struct pwm_chip *chip; diff --git a/include/linux/pwm.h b/include/linux/pwm.h index b47244a..7e99679 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -151,6 +151,29 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) return pwm ? pwm->state.polarity : PWM_POLARITY_NORMAL; } +/* + * pwm_apply_state - apply a new state to the PWM device + */ +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state); + +/* + * pwm_get_state - retrieve the current PWM state + */ +static inline void pwm_get_state(struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->state; +} + +/* + * pwm_get_default_state - retrieve the default PWM state + */ +static inline void pwm_get_default_state(struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->default_state; +} + /** * struct pwm_ops - PWM controller operations * @request: optional hook for requesting a PWM @@ -177,6 +200,9 @@ struct pwm_ops { struct pwm_device *pwm); void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); + int (*apply)(struct pwm_chip *chip, + struct pwm_device *pwm, + const struct pwm_state *state); void (*init_state)(struct pwm_chip *chip, struct pwm_device *pwm); #ifdef CONFIG_DEBUG_FS -- 1.9.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: [RFC PATCH 11/15] pwm: add the core infrastructure to allow atomic update Date: Wed, 1 Jul 2015 10:21:57 +0200 Message-ID: <1435738921-25027-12-git-send-email-boris.brezillon@free-electrons.com> References: <1435738921-25027-1-git-send-email-boris.brezillon@free-electrons.com> Return-path: In-Reply-To: <1435738921-25027-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-pwm-owner@vger.kernel.org To: Thierry Reding , linux-pwm@vger.kernel.org Cc: Mark Brown , Liam Girdwood , Bryan Wu , Richard Purdie , Jacek Anaszewski , linux-leds@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jean-Christophe Plagniol-Villard , Tomi Valkeinen , linux-fbdev@vger.kernel.org, Stephen Warren , Alexandre Courbot , linux-tegra@vger.kernel.org, Maxime Ripard , Jingoo Han , Lee Jones , Doug Anderson , Boris Brezillon List-Id: linux-leds@vger.kernel.org Add an ->apply() method to the pwm_ops struct to allow PWM drivers to implement atomic update. This method will be prefered over the ->enable(), ->disable() and ->config() methods if available. Add the pwm_get_state(), pwm_get_default_state() and pwm_apply_state() functions for PWM users to be able to use the atomic update feature. Note that the pwm_apply_state() does not guarantee the atomicity of the update operation, it all depends on the availability and implementation of the ->apply() method. Signed-off-by: Boris Brezillon --- drivers/pwm/core.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++------ include/linux/pwm.h | 26 +++++++++++++ 2 files changed, 124 insertions(+), 12 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 30631f5..6dafd8e 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -238,8 +238,9 @@ 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->ops->apply && + (!chip->ops->config || !chip->ops->enable || + !chip->ops->disable)) || !chip->npwm) return -EINVAL; mutex_lock(&pwm_lock); @@ -430,7 +431,17 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) 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 (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.period = period_ns; + state.duty_cycle = duty_ns; + + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { + err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); + } + if (err) return err; @@ -455,6 +466,17 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (!pwm || !pwm->chip->ops) return -EINVAL; + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.polarity = polarity; + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + if (!err) + pwm->state.polarity = polarity; + + return err; + } + if (!pwm->chip->ops->set_polarity) return -ENOSYS; @@ -477,17 +499,27 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity); */ int pwm_enable(struct pwm_device *pwm) { - if (pwm && !pwm_is_enabled(pwm)) { - int err; + int err; - err = pwm->chip->ops->enable(pwm->chip, pwm); - if (!err) - pwm->state.enabled = true; + if (!pwm) + return -EINVAL; - return err; + if (pwm_is_enabled(pwm)) + return 0; + + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.enabled = true; + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { + err = pwm->chip->ops->enable(pwm->chip, pwm); } - return pwm ? 0 : -EINVAL; + if (!err) + pwm->state.enabled = true; + + return err; } EXPORT_SYMBOL_GPL(pwm_enable); @@ -497,13 +529,67 @@ EXPORT_SYMBOL_GPL(pwm_enable); */ void pwm_disable(struct pwm_device *pwm) { - if (pwm && pwm_is_enabled(pwm)) { + if (!pwm || !pwm_is_enabled(pwm)) + return; + + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.enabled = false; + pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { pwm->chip->ops->disable(pwm->chip, pwm); - pwm->state.enabled = false; } + + pwm->state.enabled = false; } EXPORT_SYMBOL_GPL(pwm_disable); +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) +{ + int err = 0; + + if (!pwm) + return -EINVAL; + + if (!memcmp(state, &pwm->state, sizeof(*state))) + return 0; + + if (pwm->chip->ops->apply) { + err = pwm->chip->ops->apply(pwm->chip, pwm, state); + if (!err) + pwm->state = *state; + } else { + /* + * FIXME: restore the initial state in case of error. + */ + if (state->polarity != pwm->state.polarity) { + pwm_disable(pwm); + err = pwm_set_polarity(pwm, state->polarity); + if (err) + goto out; + } + + if (state->period != pwm->state.period || + state->duty_cycle != pwm->state.duty_cycle) { + err = pwm_config(pwm, state->period, state->duty_cycle); + if (err) + goto out; + } + + if (state->enabled != pwm->state.enabled) { + if (state->enabled) + err = pwm_enable(pwm); + else + pwm_disable(pwm); + } + } + +out: + return err; +} +EXPORT_SYMBOL_GPL(pwm_apply_state); + static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) { struct pwm_chip *chip; diff --git a/include/linux/pwm.h b/include/linux/pwm.h index b47244a..7e99679 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -151,6 +151,29 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) return pwm ? pwm->state.polarity : PWM_POLARITY_NORMAL; } +/* + * pwm_apply_state - apply a new state to the PWM device + */ +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state); + +/* + * pwm_get_state - retrieve the current PWM state + */ +static inline void pwm_get_state(struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->state; +} + +/* + * pwm_get_default_state - retrieve the default PWM state + */ +static inline void pwm_get_default_state(struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->default_state; +} + /** * struct pwm_ops - PWM controller operations * @request: optional hook for requesting a PWM @@ -177,6 +200,9 @@ struct pwm_ops { struct pwm_device *pwm); void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); + int (*apply)(struct pwm_chip *chip, + struct pwm_device *pwm, + const struct pwm_state *state); void (*init_state)(struct pwm_chip *chip, struct pwm_device *pwm); #ifdef CONFIG_DEBUG_FS -- 1.9.1 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Date: Wed, 01 Jul 2015 08:21:57 +0000 Subject: [RFC PATCH 11/15] pwm: add the core infrastructure to allow atomic update Message-Id: <1435738921-25027-12-git-send-email-boris.brezillon@free-electrons.com> List-Id: References: <1435738921-25027-1-git-send-email-boris.brezillon@free-electrons.com> In-Reply-To: <1435738921-25027-1-git-send-email-boris.brezillon@free-electrons.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Add an ->apply() method to the pwm_ops struct to allow PWM drivers to implement atomic update. This method will be prefered over the ->enable(), ->disable() and ->config() methods if available. Add the pwm_get_state(), pwm_get_default_state() and pwm_apply_state() functions for PWM users to be able to use the atomic update feature. Note that the pwm_apply_state() does not guarantee the atomicity of the update operation, it all depends on the availability and implementation of the ->apply() method. Signed-off-by: Boris Brezillon --- drivers/pwm/core.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++------ include/linux/pwm.h | 26 +++++++++++++ 2 files changed, 124 insertions(+), 12 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 30631f5..6dafd8e 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -238,8 +238,9 @@ 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->ops->apply && + (!chip->ops->config || !chip->ops->enable || + !chip->ops->disable)) || !chip->npwm) return -EINVAL; mutex_lock(&pwm_lock); @@ -430,7 +431,17 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) 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 (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.period = period_ns; + state.duty_cycle = duty_ns; + + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { + err = pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); + } + if (err) return err; @@ -455,6 +466,17 @@ int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) if (!pwm || !pwm->chip->ops) return -EINVAL; + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.polarity = polarity; + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + if (!err) + pwm->state.polarity = polarity; + + return err; + } + if (!pwm->chip->ops->set_polarity) return -ENOSYS; @@ -477,17 +499,27 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity); */ int pwm_enable(struct pwm_device *pwm) { - if (pwm && !pwm_is_enabled(pwm)) { - int err; + int err; - err = pwm->chip->ops->enable(pwm->chip, pwm); - if (!err) - pwm->state.enabled = true; + if (!pwm) + return -EINVAL; - return err; + if (pwm_is_enabled(pwm)) + return 0; + + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.enabled = true; + err = pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { + err = pwm->chip->ops->enable(pwm->chip, pwm); } - return pwm ? 0 : -EINVAL; + if (!err) + pwm->state.enabled = true; + + return err; } EXPORT_SYMBOL_GPL(pwm_enable); @@ -497,13 +529,67 @@ EXPORT_SYMBOL_GPL(pwm_enable); */ void pwm_disable(struct pwm_device *pwm) { - if (pwm && pwm_is_enabled(pwm)) { + if (!pwm || !pwm_is_enabled(pwm)) + return; + + if (pwm->chip->ops->apply) { + struct pwm_state state = pwm->state; + + state.enabled = false; + pwm->chip->ops->apply(pwm->chip, pwm, &state); + } else { pwm->chip->ops->disable(pwm->chip, pwm); - pwm->state.enabled = false; } + + pwm->state.enabled = false; } EXPORT_SYMBOL_GPL(pwm_disable); +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) +{ + int err = 0; + + if (!pwm) + return -EINVAL; + + if (!memcmp(state, &pwm->state, sizeof(*state))) + return 0; + + if (pwm->chip->ops->apply) { + err = pwm->chip->ops->apply(pwm->chip, pwm, state); + if (!err) + pwm->state = *state; + } else { + /* + * FIXME: restore the initial state in case of error. + */ + if (state->polarity != pwm->state.polarity) { + pwm_disable(pwm); + err = pwm_set_polarity(pwm, state->polarity); + if (err) + goto out; + } + + if (state->period != pwm->state.period || + state->duty_cycle != pwm->state.duty_cycle) { + err = pwm_config(pwm, state->period, state->duty_cycle); + if (err) + goto out; + } + + if (state->enabled != pwm->state.enabled) { + if (state->enabled) + err = pwm_enable(pwm); + else + pwm_disable(pwm); + } + } + +out: + return err; +} +EXPORT_SYMBOL_GPL(pwm_apply_state); + static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) { struct pwm_chip *chip; diff --git a/include/linux/pwm.h b/include/linux/pwm.h index b47244a..7e99679 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -151,6 +151,29 @@ static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm) return pwm ? pwm->state.polarity : PWM_POLARITY_NORMAL; } +/* + * pwm_apply_state - apply a new state to the PWM device + */ +int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state); + +/* + * pwm_get_state - retrieve the current PWM state + */ +static inline void pwm_get_state(struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->state; +} + +/* + * pwm_get_default_state - retrieve the default PWM state + */ +static inline void pwm_get_default_state(struct pwm_device *pwm, + struct pwm_state *state) +{ + *state = pwm->default_state; +} + /** * struct pwm_ops - PWM controller operations * @request: optional hook for requesting a PWM @@ -177,6 +200,9 @@ struct pwm_ops { struct pwm_device *pwm); void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm); + int (*apply)(struct pwm_chip *chip, + struct pwm_device *pwm, + const struct pwm_state *state); void (*init_state)(struct pwm_chip *chip, struct pwm_device *pwm); #ifdef CONFIG_DEBUG_FS -- 1.9.1