From: Boris Brezillon <boris.brezillon@free-electrons.com> To: Thierry Reding <thierry.reding@gmail.com>, linux-pwm@vger.kernel.org, Mark Brown <broonie@kernel.org>, Liam Girdwood <lgirdwood@gmail.com> Cc: Heiko Stuebner <heiko@sntech.de>, linux-rockchip@lists.infradead.org, Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim <milo.kim@ti.com>, Doug Anderson <dianders@google.com>, Caesar Wang <wxt@rock-chips.com>, Stephen Barber <smbarber@chromium.org>, Brian Norris <briannorris@chromium.org>, Ajit Pal Singh <ajitpal.singh@st.com>, Srinivas Kandagatla <srinivas.kandagatla@gmail.com>, Maxime Coquelin <maxime.coquelin@st.com>, Patrice Chotard <patrice.chotard@st.com>, kernel@stlinux.com, Boris Brezillon <boris.brezillon@free-electrons.com> Subject: [PATCH 01/14] pwm: Add new helpers to create/manipulate PWM states Date: Fri, 3 Jun 2016 10:22:59 +0200 [thread overview] Message-ID: <1464942192-25967-2-git-send-email-boris.brezillon@free-electrons.com> (raw) In-Reply-To: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> The pwm_prepare_new_state() helper prepares a new state object containing the current PWM state except for the polarity and period fields which are set to the reference values. This is particurly useful for PWM users who want to apply a new duty-cycle expressed relatively to the reference period without changing the enable state. The PWM framework expect PWM users to configure the duty cycle in nanosecond, but most users just want to express this duty cycle relatively to the period value (i.e. duty_cycle = 33% of the period). Add pwm_{get,set}_relative_duty_cycle() helpers to ease this kind of conversion. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> --- include/linux/pwm.h | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 17018f3..e09babf 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -148,6 +148,87 @@ static inline void pwm_get_args(const struct pwm_device *pwm, } /** + * pwm_prepare_new_state() - prepare a new state to be applied with + * pwm_apply_state() + * @pwm: PWM device + * @state: state to fill with the prepared PWM state + * + * This functions prepares a state that can later be tweaked and applied + * to the PWM device with pwm_apply_state(). This is a convenient function + * that first retrieves the current PWM state and the replaces the period + * and polarity fields with the reference values defined in pwm->args. + * Once the new state is created you can adjust the ->enable and ->duty_cycle + * according to your need before calling pwm_apply_state(). + */ +static inline void pwm_prepare_new_state(const struct pwm_device *pwm, + struct pwm_state *state) +{ + struct pwm_args args; + + /* First get the current state. */ + pwm_get_state(pwm, state); + + /* Then fill it with the reference config */ + pwm_get_args(pwm, &args); + + state->period = args.period; + state->polarity = args.polarity; + state->duty_cycle = 0; +} + +/** + * pwm_get_relative_duty_cycle() - Get a relative duty_cycle value + * @state: the PWM state to extract period and duty_cycle from + * @scale: the scale you want to use for you relative duty_cycle value + * + * This functions converts the absolute duty_cycle stored in @state + * (expressed in nanosecond) into a relative value. + * For example if you want to get the duty_cycle expressed in nanosecond, + * call: + * + * pwm_get_state(pwm, &state); + * duty = pwm_get_relative_duty_cycle(&state, 100); + */ +static inline unsigned int +pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale) +{ + if (!state->period) + return 0; + + return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale, + state->period); +} + +/** + * pwm_set_relative_duty_cycle() - Set a relative duty_cycle value + * @state: the PWM state to fill + * @val: the relative duty_cycle value + * @scale: the scale you use for you relative duty_cycle value + * + * This functions converts a relative duty_cycle stored into an absolute + * one (expressed in nanoseconds), and put the result in state->duty_cycle. + * For example if you want to change configure a 50% duty_cycle, call: + * + * pwm_prepare_new_state(pwm, &state); + * pwm_set_relative_duty_cycle(&state, 50, 100); + * pwm_apply_state(pwm, &state); + */ +static inline void +pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int val, + unsigned int scale) +{ + if (!scale) + return; + + /* Make sure we don't have duty_cycle > period */ + if (val > scale) + val = scale; + + state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)val * state->period, + scale); +} + +/** * struct pwm_ops - PWM controller operations * @request: optional hook for requesting a PWM * @free: optional hook for freeing a PWM -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: boris.brezillon@free-electrons.com (Boris Brezillon) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 01/14] pwm: Add new helpers to create/manipulate PWM states Date: Fri, 3 Jun 2016 10:22:59 +0200 [thread overview] Message-ID: <1464942192-25967-2-git-send-email-boris.brezillon@free-electrons.com> (raw) In-Reply-To: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> The pwm_prepare_new_state() helper prepares a new state object containing the current PWM state except for the polarity and period fields which are set to the reference values. This is particurly useful for PWM users who want to apply a new duty-cycle expressed relatively to the reference period without changing the enable state. The PWM framework expect PWM users to configure the duty cycle in nanosecond, but most users just want to express this duty cycle relatively to the period value (i.e. duty_cycle = 33% of the period). Add pwm_{get,set}_relative_duty_cycle() helpers to ease this kind of conversion. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> --- include/linux/pwm.h | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 17018f3..e09babf 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -148,6 +148,87 @@ static inline void pwm_get_args(const struct pwm_device *pwm, } /** + * pwm_prepare_new_state() - prepare a new state to be applied with + * pwm_apply_state() + * @pwm: PWM device + * @state: state to fill with the prepared PWM state + * + * This functions prepares a state that can later be tweaked and applied + * to the PWM device with pwm_apply_state(). This is a convenient function + * that first retrieves the current PWM state and the replaces the period + * and polarity fields with the reference values defined in pwm->args. + * Once the new state is created you can adjust the ->enable and ->duty_cycle + * according to your need before calling pwm_apply_state(). + */ +static inline void pwm_prepare_new_state(const struct pwm_device *pwm, + struct pwm_state *state) +{ + struct pwm_args args; + + /* First get the current state. */ + pwm_get_state(pwm, state); + + /* Then fill it with the reference config */ + pwm_get_args(pwm, &args); + + state->period = args.period; + state->polarity = args.polarity; + state->duty_cycle = 0; +} + +/** + * pwm_get_relative_duty_cycle() - Get a relative duty_cycle value + * @state: the PWM state to extract period and duty_cycle from + * @scale: the scale you want to use for you relative duty_cycle value + * + * This functions converts the absolute duty_cycle stored in @state + * (expressed in nanosecond) into a relative value. + * For example if you want to get the duty_cycle expressed in nanosecond, + * call: + * + * pwm_get_state(pwm, &state); + * duty = pwm_get_relative_duty_cycle(&state, 100); + */ +static inline unsigned int +pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale) +{ + if (!state->period) + return 0; + + return DIV_ROUND_CLOSEST_ULL((u64)state->duty_cycle * scale, + state->period); +} + +/** + * pwm_set_relative_duty_cycle() - Set a relative duty_cycle value + * @state: the PWM state to fill + * @val: the relative duty_cycle value + * @scale: the scale you use for you relative duty_cycle value + * + * This functions converts a relative duty_cycle stored into an absolute + * one (expressed in nanoseconds), and put the result in state->duty_cycle. + * For example if you want to change configure a 50% duty_cycle, call: + * + * pwm_prepare_new_state(pwm, &state); + * pwm_set_relative_duty_cycle(&state, 50, 100); + * pwm_apply_state(pwm, &state); + */ +static inline void +pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int val, + unsigned int scale) +{ + if (!scale) + return; + + /* Make sure we don't have duty_cycle > period */ + if (val > scale) + val = scale; + + state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)val * state->period, + scale); +} + +/** * struct pwm_ops - PWM controller operations * @request: optional hook for requesting a PWM * @free: optional hook for freeing a PWM -- 2.7.4
next prev parent reply other threads:[~2016-06-03 8:23 UTC|newest] Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-03 8:22 [PATCH 00/14] regulator: pwm: various improvements Boris Brezillon 2016-06-03 8:22 ` Boris Brezillon 2016-06-03 8:22 ` Boris Brezillon 2016-06-03 8:22 ` Boris Brezillon [this message] 2016-06-03 8:22 ` [PATCH 01/14] pwm: Add new helpers to create/manipulate PWM states Boris Brezillon 2016-06-03 8:23 ` [PATCH 02/14] regulator: pwm: Drop unneeded pwm_enable() call Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 11:08 ` Applied "regulator: pwm: Drop unneeded pwm_enable() call" to the regulator tree Mark Brown 2016-06-03 11:08 ` Mark Brown 2016-06-03 11:08 ` Mark Brown 2016-06-03 11:08 ` Mark Brown 2016-06-03 8:23 ` [PATCH 03/14] pwm: rockchip: Fix period and duty_cycle approximation Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:03 ` Brian Norris 2016-06-03 20:03 ` Brian Norris 2016-06-04 6:19 ` Boris Brezillon 2016-06-04 6:19 ` Boris Brezillon 2016-06-07 17:25 ` Brian Norris 2016-06-07 17:25 ` Brian Norris 2016-06-03 8:23 ` [PATCH 04/14] pwm: rockchip: Add support for hardware readout Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:07 ` Brian Norris 2016-06-03 20:07 ` Brian Norris 2016-06-03 20:20 ` Brian Norris 2016-06-03 20:20 ` Brian Norris 2016-06-04 6:24 ` Boris Brezillon 2016-06-04 6:24 ` Boris Brezillon 2016-06-07 17:26 ` Brian Norris 2016-06-07 17:26 ` Brian Norris 2016-06-03 8:23 ` [PATCH 05/14] pwm: rockchip: Avoid glitches on already running PWMs Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:28 ` Brian Norris 2016-06-03 20:28 ` Brian Norris 2016-06-04 6:26 ` Boris Brezillon 2016-06-04 6:26 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 06/14] pwm: rockchip: Add support for atomic update Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:37 ` Brian Norris 2016-06-03 20:37 ` Brian Norris 2016-06-03 20:37 ` Brian Norris 2016-06-03 8:23 ` [PATCH 07/14] pwm: sti: Add support for hardware readout Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 08/14] pwm: sti: Avoid glitches on already running PWMs Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:38 ` Brian Norris 2016-06-03 20:38 ` Brian Norris 2016-06-03 20:38 ` Brian Norris 2016-06-03 8:23 ` [PATCH 09/14] regulator: pwm: Adjust PWM config at probe time Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:41 ` Brian Norris 2016-06-03 20:41 ` Brian Norris 2016-06-03 8:23 ` [PATCH 10/14] regulator: pwm: Switch to the atomic PWM API Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:50 ` Brian Norris 2016-06-03 20:50 ` Brian Norris 2016-06-03 20:50 ` Brian Norris 2016-06-04 6:28 ` Boris Brezillon 2016-06-04 6:28 ` Boris Brezillon 2016-06-06 6:14 ` Laxman Dewangan 2016-06-06 6:14 ` Laxman Dewangan 2016-06-06 6:14 ` Laxman Dewangan 2016-06-03 8:23 ` [PATCH 11/14] regulator: pwm: properly initialize the ->state field Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:51 ` Brian Norris 2016-06-03 20:51 ` Brian Norris 2016-06-03 8:23 ` [PATCH 12/14] regulator: pwm: Retrieve correct voltage Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 20:55 ` Brian Norris 2016-06-03 20:55 ` Brian Norris 2016-06-03 8:23 ` [PATCH 13/14] regulator: pwm: Support extra continuous mode cases Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 21:03 ` Brian Norris 2016-06-03 21:03 ` Brian Norris 2016-06-04 6:30 ` Boris Brezillon 2016-06-04 6:30 ` Boris Brezillon 2016-06-03 8:23 ` [PATCH 14/14] regulator: pwm: Document pwm-dutycycle-unit and pwm-dutycycle-range Boris Brezillon 2016-06-03 8:23 ` Boris Brezillon 2016-06-03 21:04 ` Brian Norris 2016-06-03 21:04 ` Brian Norris 2016-06-03 21:04 ` Brian Norris 2016-06-06 14:09 ` Rob Herring 2016-06-06 14:09 ` Rob Herring
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