From patchwork Wed Nov 29 09:13:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 13472474 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="LoKPPoGM"; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="SexUUXmK" X-Greylist: delayed 309 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Wed, 29 Nov 2023 01:14:06 PST Received: from gofer.mess.org (gofer.mess.org [IPv6:2a02:8011:d000:212::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37A181A5; Wed, 29 Nov 2023 01:14:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1701249244; bh=KpBkbH+c4Cv+OYyJKsCXnXYg/xvIBdkcAJWnSuSnKrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LoKPPoGMtq7Rp7kAXCn1vrI6f0tixAJryH8Tt97bhn1HTWYnrJWLvHfB8DKNWN9rU KOAsc3SDSoOur/KUiUSilJkeyq0xLTQy100K7BvblkInGhgNcOfJjFMwSXSYZFeBrw cjREBCqQQWW+uiu66QjDa6+Pjg73y/hqLUQVmVy/siQ1AX2hNL9szeUPJs9facwEOG jPhodtto5t17RQNkKtMIam0Cb5oq4TkE0FoJeKQ1sRPXSyOo2khEhZjsiY5KnUTzch PCHSYNDrVH0Y/7YCnZuymL/q9eNjBoW1Tiohk9Ny3VWXMdYWpUBOKz8fzNtlnLtc5N NVcXKYUOu8R7A== Received: by gofer.mess.org (Postfix, from userid 501) id C9171100105; Wed, 29 Nov 2023 09:14:04 +0000 (GMT) X-Spam-Level: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1701249228; bh=KpBkbH+c4Cv+OYyJKsCXnXYg/xvIBdkcAJWnSuSnKrM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SexUUXmKGZMDHdT5eX6AGHRNxooQwTa82cvWWFpLmWnV3zJMgmp+Jx4f+PaIgpxW+ OmU7tpy7wOS0irUBFrI2UjGwcRRxbLBffQNxZjXn8KbeLa5tFGgYg29yonApbJJl9j uc/ZlqzSC6ayZAyFuDsuw08EX/c4QAgTaiiKaVPl/mJnBnP2+rPq8sTfkg2lA7t3Xk 6OgNXlK7wPMP9kOI8ZNk9+aIALpQ6Mv3diOOVgo9dgl2+cpNpab3kQKYhF+uQyyyG2 fTyWBVmG/Uaqs+aG/sLP0LBZQ3mHKfs2HhZtXzZIG+L/Cf6lnSRTLOzc9oNoGFI+Za 31kBZf4h0Pnvg== Received: from localhost.localdomain (bigcore-99.local [IPv6:2a02:8011:d000:212:ca7f:54ff:fe51:14d6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by gofer.mess.org (Postfix) with ESMTPSA id 9C1A8100100; Wed, 29 Nov 2023 09:13:48 +0000 (GMT) From: Sean Young To: linux-media@vger.kernel.org, linux-pwm@vger.kernel.org, Ivaylo Dimitrov , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Jonathan Corbet , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , David Airlie , Daniel Vetter , Javier Martinez Canillas , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Jean Delvare , Guenter Roeck , Support Opensource , Dmitry Torokhov , Pavel Machek , Lee Jones , Sean Young , Mauro Carvalho Chehab , Hans de Goede , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Mark Gross , Liam Girdwood , Mark Brown , Daniel Thompson , Jingoo Han , Helge Deller Cc: Jani Nikula , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-hwmon@vger.kernel.org, linux-input@vger.kernel.org, linux-leds@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-fbdev@vger.kernel.org Subject: [PATCH v6 1/4] pwm: rename pwm_apply_state() to pwm_apply_might_sleep() Date: Wed, 29 Nov 2023 09:13:34 +0000 Message-ID: <37090c1d8d8f42f1e12fa84942027d995189a99e.1701248996.git.sean@mess.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In order to introduce a pwm api which can be used from atomic context, we will need two functions for applying pwm changes: int pwm_apply_might_sleep(struct pwm *, struct pwm_state *); int pwm_apply_atomic(struct pwm *, struct pwm_state *); This commit just deals with renaming pwm_apply_state(), a following commit will introduce the pwm_apply_atomic() function. Acked-by: Hans de Goede Acked-by: Jani Nikula Acked-by: Lee Jones Signed-off-by: Sean Young Acked-by: Dmitry Torokhov # for input --- Documentation/driver-api/pwm.rst | 8 +++--- .../gpu/drm/i915/display/intel_backlight.c | 6 ++-- drivers/gpu/drm/solomon/ssd130x.c | 2 +- drivers/hwmon/pwm-fan.c | 8 +++--- drivers/input/misc/da7280.c | 4 +-- drivers/input/misc/pwm-beeper.c | 4 +-- drivers/input/misc/pwm-vibra.c | 8 +++--- drivers/leds/leds-pwm.c | 2 +- drivers/leds/rgb/leds-pwm-multicolor.c | 4 +-- drivers/media/rc/pwm-ir-tx.c | 4 +-- drivers/platform/x86/lenovo-yogabook.c | 2 +- drivers/pwm/core.c | 18 ++++++------ drivers/pwm/pwm-twl-led.c | 2 +- drivers/pwm/pwm-vt8500.c | 2 +- drivers/pwm/sysfs.c | 10 +++---- drivers/regulator/pwm-regulator.c | 4 +-- drivers/video/backlight/lm3630a_bl.c | 2 +- drivers/video/backlight/lp855x_bl.c | 2 +- drivers/video/backlight/pwm_bl.c | 12 ++++---- drivers/video/fbdev/ssd1307fb.c | 2 +- include/linux/pwm.h | 28 +++++++++---------- 21 files changed, 67 insertions(+), 67 deletions(-) diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index bb264490a87a..f1d8197c8c43 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -41,7 +41,7 @@ the getter, devm_pwm_get() and devm_fwnode_pwm_get(), also exist. After being requested, a PWM has to be configured using:: - int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state); + int pwm_apply_might_sleep(struct pwm_device *pwm, struct pwm_state *state); This API controls both the PWM period/duty_cycle config and the enable/disable state. @@ -57,13 +57,13 @@ If supported by the driver, the signal can be optimized, for example to improve EMI by phase shifting the individual channels of a chip. The pwm_config(), pwm_enable() and pwm_disable() functions are just wrappers -around pwm_apply_state() and should not be used if the user wants to change +around pwm_apply_might_sleep() and should not be used if the user wants to change several parameter at once. For example, if you see pwm_config() and pwm_{enable,disable}() calls in the same function, this probably means you -should switch to pwm_apply_state(). +should switch to pwm_apply_might_sleep(). The PWM user API also allows one to query the PWM state that was passed to the -last invocation of pwm_apply_state() using pwm_get_state(). Note this is +last invocation of pwm_apply_might_sleep() using pwm_get_state(). Note this is different to what the driver has actually implemented if the request cannot be satisfied exactly with the hardware in use. There is currently no way for consumers to get the actually implemented settings. diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c index 2e8f17c04522..ff9b9918b0a1 100644 --- a/drivers/gpu/drm/i915/display/intel_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_backlight.c @@ -274,7 +274,7 @@ static void ext_pwm_set_backlight(const struct drm_connector_state *conn_state, struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel; pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100); - pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state); + pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state); } static void @@ -427,7 +427,7 @@ static void ext_pwm_disable_backlight(const struct drm_connector_state *old_conn intel_backlight_set_pwm_level(old_conn_state, level); panel->backlight.pwm_state.enabled = false; - pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state); + pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state); } void intel_backlight_disable(const struct drm_connector_state *old_conn_state) @@ -749,7 +749,7 @@ static void ext_pwm_enable_backlight(const struct intel_crtc_state *crtc_state, pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100); panel->backlight.pwm_state.enabled = true; - pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state); + pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state); } static void __intel_backlight_enable(const struct intel_crtc_state *crtc_state, diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c index e0174f82e353..cce043a4a1dc 100644 --- a/drivers/gpu/drm/solomon/ssd130x.c +++ b/drivers/gpu/drm/solomon/ssd130x.c @@ -319,7 +319,7 @@ static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x) pwm_init_state(ssd130x->pwm, &pwmstate); pwm_set_relative_duty_cycle(&pwmstate, 50, 100); - pwm_apply_state(ssd130x->pwm, &pwmstate); + pwm_apply_might_sleep(ssd130x->pwm, &pwmstate); /* Enable the PWM */ pwm_enable(ssd130x->pwm); diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 6e4516c2ab89..b67bc9e833c0 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -151,7 +151,7 @@ static int pwm_fan_power_on(struct pwm_fan_ctx *ctx) } state->enabled = true; - ret = pwm_apply_state(ctx->pwm, state); + ret = pwm_apply_might_sleep(ctx->pwm, state); if (ret) { dev_err(ctx->dev, "failed to enable PWM\n"); goto disable_regulator; @@ -181,7 +181,7 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx) state->enabled = false; state->duty_cycle = 0; - ret = pwm_apply_state(ctx->pwm, state); + ret = pwm_apply_might_sleep(ctx->pwm, state); if (ret) { dev_err(ctx->dev, "failed to disable PWM\n"); return ret; @@ -207,7 +207,7 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) period = state->period; state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); - ret = pwm_apply_state(ctx->pwm, state); + ret = pwm_apply_might_sleep(ctx->pwm, state); if (ret) return ret; ret = pwm_fan_power_on(ctx); @@ -278,7 +278,7 @@ static int pwm_fan_update_enable(struct pwm_fan_ctx *ctx, long val) state, &enable_regulator); - pwm_apply_state(ctx->pwm, state); + pwm_apply_might_sleep(ctx->pwm, state); pwm_fan_switch_power(ctx, enable_regulator); pwm_fan_update_state(ctx, 0); } diff --git a/drivers/input/misc/da7280.c b/drivers/input/misc/da7280.c index ce82548916bb..c1fa75c0f970 100644 --- a/drivers/input/misc/da7280.c +++ b/drivers/input/misc/da7280.c @@ -352,7 +352,7 @@ static int da7280_haptic_set_pwm(struct da7280_haptic *haptics, bool enabled) state.duty_cycle = period_mag_multi; } - error = pwm_apply_state(haptics->pwm_dev, &state); + error = pwm_apply_might_sleep(haptics->pwm_dev, &state); if (error) dev_err(haptics->dev, "Failed to apply pwm state: %d\n", error); @@ -1175,7 +1175,7 @@ static int da7280_probe(struct i2c_client *client) /* Sync up PWM state and ensure it is off. */ pwm_init_state(haptics->pwm_dev, &state); state.enabled = false; - error = pwm_apply_state(haptics->pwm_dev, &state); + error = pwm_apply_might_sleep(haptics->pwm_dev, &state); if (error) { dev_err(dev, "Failed to apply PWM state: %d\n", error); return error; diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c index 1e731d8397c6..5b9aedf4362f 100644 --- a/drivers/input/misc/pwm-beeper.c +++ b/drivers/input/misc/pwm-beeper.c @@ -39,7 +39,7 @@ static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period) state.period = period; pwm_set_relative_duty_cycle(&state, 50, 100); - error = pwm_apply_state(beeper->pwm, &state); + error = pwm_apply_might_sleep(beeper->pwm, &state); if (error) return error; @@ -138,7 +138,7 @@ static int pwm_beeper_probe(struct platform_device *pdev) /* Sync up PWM state and ensure it is off. */ pwm_init_state(beeper->pwm, &state); state.enabled = false; - error = pwm_apply_state(beeper->pwm, &state); + error = pwm_apply_might_sleep(beeper->pwm, &state); if (error) { dev_err(dev, "failed to apply initial PWM state: %d\n", error); diff --git a/drivers/input/misc/pwm-vibra.c b/drivers/input/misc/pwm-vibra.c index acac79c488aa..3e5ed685ed8f 100644 --- a/drivers/input/misc/pwm-vibra.c +++ b/drivers/input/misc/pwm-vibra.c @@ -56,7 +56,7 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator) pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff); state.enabled = true; - err = pwm_apply_state(vibrator->pwm, &state); + err = pwm_apply_might_sleep(vibrator->pwm, &state); if (err) { dev_err(pdev, "failed to apply pwm state: %d\n", err); return err; @@ -67,7 +67,7 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator) state.duty_cycle = vibrator->direction_duty_cycle; state.enabled = true; - err = pwm_apply_state(vibrator->pwm_dir, &state); + err = pwm_apply_might_sleep(vibrator->pwm_dir, &state); if (err) { dev_err(pdev, "failed to apply dir-pwm state: %d\n", err); pwm_disable(vibrator->pwm); @@ -160,7 +160,7 @@ static int pwm_vibrator_probe(struct platform_device *pdev) /* Sync up PWM state and ensure it is off. */ pwm_init_state(vibrator->pwm, &state); state.enabled = false; - err = pwm_apply_state(vibrator->pwm, &state); + err = pwm_apply_might_sleep(vibrator->pwm, &state); if (err) { dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n", err); @@ -174,7 +174,7 @@ static int pwm_vibrator_probe(struct platform_device *pdev) /* Sync up PWM state and ensure it is off. */ pwm_init_state(vibrator->pwm_dir, &state); state.enabled = false; - err = pwm_apply_state(vibrator->pwm_dir, &state); + err = pwm_apply_might_sleep(vibrator->pwm_dir, &state); if (err) { dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n", err); diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index 2b3bf1353b70..4e3936a39d0e 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -54,7 +54,7 @@ static int led_pwm_set(struct led_classdev *led_cdev, led_dat->pwmstate.duty_cycle = duty; led_dat->pwmstate.enabled = true; - return pwm_apply_state(led_dat->pwm, &led_dat->pwmstate); + return pwm_apply_might_sleep(led_dat->pwm, &led_dat->pwmstate); } __attribute__((nonnull)) diff --git a/drivers/leds/rgb/leds-pwm-multicolor.c b/drivers/leds/rgb/leds-pwm-multicolor.c index 46cd062b8b24..e1a81e0109e8 100644 --- a/drivers/leds/rgb/leds-pwm-multicolor.c +++ b/drivers/leds/rgb/leds-pwm-multicolor.c @@ -51,8 +51,8 @@ static int led_pwm_mc_set(struct led_classdev *cdev, priv->leds[i].state.duty_cycle = duty; priv->leds[i].state.enabled = duty > 0; - ret = pwm_apply_state(priv->leds[i].pwm, - &priv->leds[i].state); + ret = pwm_apply_might_sleep(priv->leds[i].pwm, + &priv->leds[i].state); if (ret) break; } diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c index c5f37c03af9c..cf51e2760975 100644 --- a/drivers/media/rc/pwm-ir-tx.c +++ b/drivers/media/rc/pwm-ir-tx.c @@ -68,7 +68,7 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, for (i = 0; i < count; i++) { state.enabled = !(i % 2); - pwm_apply_state(pwm, &state); + pwm_apply_might_sleep(pwm, &state); edge = ktime_add_us(edge, txbuf[i]); delta = ktime_us_delta(edge, ktime_get()); @@ -77,7 +77,7 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, } state.enabled = false; - pwm_apply_state(pwm, &state); + pwm_apply_might_sleep(pwm, &state); return count; } diff --git a/drivers/platform/x86/lenovo-yogabook.c b/drivers/platform/x86/lenovo-yogabook.c index b8d0239192cb..fd62bf746ebd 100644 --- a/drivers/platform/x86/lenovo-yogabook.c +++ b/drivers/platform/x86/lenovo-yogabook.c @@ -435,7 +435,7 @@ static int yogabook_pdev_set_kbd_backlight(struct yogabook_data *data, u8 level) .enabled = level, }; - pwm_apply_state(data->kbd_bl_pwm, &state); + pwm_apply_might_sleep(data->kbd_bl_pwm, &state); gpiod_set_value(data->kbd_bl_led_enable, level ? 1 : 0); return 0; } diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 29078486534d..fc92ba622e56 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -356,8 +356,8 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, } EXPORT_SYMBOL_GPL(pwm_request_from_chip); -static void pwm_apply_state_debug(struct pwm_device *pwm, - const struct pwm_state *state) +static void pwm_apply_debug(struct pwm_device *pwm, + const struct pwm_state *state) { struct pwm_state *last = &pwm->last; struct pwm_chip *chip = pwm->chip; @@ -463,11 +463,11 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, } /** - * pwm_apply_state() - atomically apply a new state to a PWM device + * pwm_apply_might_sleep() - atomically apply a new state to a PWM device * @pwm: PWM device * @state: new state to apply */ -int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) +int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) { struct pwm_chip *chip; int err; @@ -475,7 +475,7 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) /* * Some lowlevel driver's implementations of .apply() make use of * mutexes, also with some drivers only returning when the new - * configuration is active calling pwm_apply_state() from atomic context + * configuration is active calling pwm_apply_might_sleep() from atomic context * is a bad idea. So make it explicit that calling this function might * sleep. */ @@ -505,11 +505,11 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) * only do this after pwm->state was applied as some * implementations of .get_state depend on this */ - pwm_apply_state_debug(pwm, state); + pwm_apply_debug(pwm, state); return 0; } -EXPORT_SYMBOL_GPL(pwm_apply_state); +EXPORT_SYMBOL_GPL(pwm_apply_might_sleep); /** * pwm_capture() - capture and report a PWM signal @@ -567,7 +567,7 @@ int pwm_adjust_config(struct pwm_device *pwm) state.period = pargs.period; state.polarity = pargs.polarity; - return pwm_apply_state(pwm, &state); + return pwm_apply_might_sleep(pwm, &state); } /* @@ -590,7 +590,7 @@ int pwm_adjust_config(struct pwm_device *pwm) state.duty_cycle = state.period - state.duty_cycle; } - return pwm_apply_state(pwm, &state); + return pwm_apply_might_sleep(pwm, &state); } EXPORT_SYMBOL_GPL(pwm_adjust_config); diff --git a/drivers/pwm/pwm-twl-led.c b/drivers/pwm/pwm-twl-led.c index 625233f4703a..70eec1c66747 100644 --- a/drivers/pwm/pwm-twl-led.c +++ b/drivers/pwm/pwm-twl-led.c @@ -172,7 +172,7 @@ static int twl4030_pwmled_apply(struct pwm_chip *chip, struct pwm_device *pwm, * We cannot skip calling ->config even if state->period == * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle * because we might have exited early in the last call to - * pwm_apply_state because of !state->enabled and so the two values in + * pwm_apply_might_sleep because of !state->enabled and so the two values in * pwm->state might not be configured in hardware. */ ret = twl4030_pwmled_config(pwm->chip, pwm, diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c index 5568d5312d3c..3d1d11062558 100644 --- a/drivers/pwm/pwm-vt8500.c +++ b/drivers/pwm/pwm-vt8500.c @@ -206,7 +206,7 @@ static int vt8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, * We cannot skip calling ->config even if state->period == * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle * because we might have exited early in the last call to - * pwm_apply_state because of !state->enabled and so the two values in + * pwm_apply_might_sleep because of !state->enabled and so the two values in * pwm->state might not be configured in hardware. */ err = vt8500_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period); diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 8d1254761e4d..052ccadbdabf 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -62,7 +62,7 @@ static ssize_t period_store(struct device *child, mutex_lock(&export->lock); pwm_get_state(pwm, &state); state.period = val; - ret = pwm_apply_state(pwm, &state); + ret = pwm_apply_might_sleep(pwm, &state); mutex_unlock(&export->lock); return ret ? : size; @@ -97,7 +97,7 @@ static ssize_t duty_cycle_store(struct device *child, mutex_lock(&export->lock); pwm_get_state(pwm, &state); state.duty_cycle = val; - ret = pwm_apply_state(pwm, &state); + ret = pwm_apply_might_sleep(pwm, &state); mutex_unlock(&export->lock); return ret ? : size; @@ -144,7 +144,7 @@ static ssize_t enable_store(struct device *child, goto unlock; } - ret = pwm_apply_state(pwm, &state); + ret = pwm_apply_might_sleep(pwm, &state); unlock: mutex_unlock(&export->lock); @@ -194,7 +194,7 @@ static ssize_t polarity_store(struct device *child, mutex_lock(&export->lock); pwm_get_state(pwm, &state); state.polarity = polarity; - ret = pwm_apply_state(pwm, &state); + ret = pwm_apply_might_sleep(pwm, &state); mutex_unlock(&export->lock); return ret ? : size; @@ -401,7 +401,7 @@ static int pwm_class_apply_state(struct pwm_export *export, struct pwm_device *pwm, struct pwm_state *state) { - int ret = pwm_apply_state(pwm, state); + int ret = pwm_apply_might_sleep(pwm, state); /* release lock taken in pwm_class_get_state */ mutex_unlock(&export->lock); diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c index 2aff6db748e2..698c420e0869 100644 --- a/drivers/regulator/pwm-regulator.c +++ b/drivers/regulator/pwm-regulator.c @@ -90,7 +90,7 @@ static int pwm_regulator_set_voltage_sel(struct regulator_dev *rdev, pwm_set_relative_duty_cycle(&pstate, drvdata->duty_cycle_table[selector].dutycycle, 100); - ret = pwm_apply_state(drvdata->pwm, &pstate); + ret = pwm_apply_might_sleep(drvdata->pwm, &pstate); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); return ret; @@ -216,7 +216,7 @@ static int pwm_regulator_set_voltage(struct regulator_dev *rdev, pwm_set_relative_duty_cycle(&pstate, dutycycle, duty_unit); - ret = pwm_apply_state(drvdata->pwm, &pstate); + ret = pwm_apply_might_sleep(drvdata->pwm, &pstate); if (ret) { dev_err(&rdev->dev, "Failed to configure PWM: %d\n", ret); return ret; diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c index 8fcb62be597b..a3412c936ca2 100644 --- a/drivers/video/backlight/lm3630a_bl.c +++ b/drivers/video/backlight/lm3630a_bl.c @@ -180,7 +180,7 @@ static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max) pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false; - return pwm_apply_state(pchip->pwmd, &pchip->pwmd_state); + return pwm_apply_might_sleep(pchip->pwmd, &pchip->pwmd_state); } /* update and get brightness */ diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c index da1f124db69c..7075bfab59c4 100644 --- a/drivers/video/backlight/lp855x_bl.c +++ b/drivers/video/backlight/lp855x_bl.c @@ -234,7 +234,7 @@ static int lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br) state.duty_cycle = div_u64(br * state.period, max_br); state.enabled = state.duty_cycle; - return pwm_apply_state(lp->pwm, &state); + return pwm_apply_might_sleep(lp->pwm, &state); } static int lp855x_bl_update_status(struct backlight_device *bl) diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 289bd9ce4d36..35c716e9043c 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -103,7 +103,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) pwm_get_state(pb->pwm, &state); state.duty_cycle = compute_duty_cycle(pb, brightness, &state); state.enabled = true; - pwm_apply_state(pb->pwm, &state); + pwm_apply_might_sleep(pb->pwm, &state); pwm_backlight_power_on(pb); } else { @@ -120,7 +120,7 @@ static int pwm_backlight_update_status(struct backlight_device *bl) * inactive output. */ state.enabled = !pb->power_supply && !pb->enable_gpio; - pwm_apply_state(pb->pwm, &state); + pwm_apply_might_sleep(pb->pwm, &state); } if (pb->notify_after) @@ -528,7 +528,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) if (!state.period && (data->pwm_period_ns > 0)) state.period = data->pwm_period_ns; - ret = pwm_apply_state(pb->pwm, &state); + ret = pwm_apply_might_sleep(pb->pwm, &state); if (ret) { dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n", ret); @@ -633,7 +633,7 @@ static void pwm_backlight_remove(struct platform_device *pdev) pwm_get_state(pb->pwm, &state); state.duty_cycle = 0; state.enabled = false; - pwm_apply_state(pb->pwm, &state); + pwm_apply_might_sleep(pb->pwm, &state); if (pb->exit) pb->exit(&pdev->dev); @@ -649,7 +649,7 @@ static void pwm_backlight_shutdown(struct platform_device *pdev) pwm_get_state(pb->pwm, &state); state.duty_cycle = 0; state.enabled = false; - pwm_apply_state(pb->pwm, &state); + pwm_apply_might_sleep(pb->pwm, &state); } #ifdef CONFIG_PM_SLEEP @@ -673,7 +673,7 @@ static int pwm_backlight_suspend(struct device *dev) pwm_get_state(pb->pwm, &state); state.duty_cycle = 0; state.enabled = false; - pwm_apply_state(pb->pwm, &state); + pwm_apply_might_sleep(pb->pwm, &state); if (pb->notify_after) pb->notify_after(pb->dev, 0); diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index 5ae48e36fccb..1a4f90ea7d5a 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -347,7 +347,7 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) pwm_init_state(par->pwm, &pwmstate); pwm_set_relative_duty_cycle(&pwmstate, 50, 100); - pwm_apply_state(par->pwm, &pwmstate); + pwm_apply_might_sleep(par->pwm, &pwmstate); /* Enable the PWM */ pwm_enable(par->pwm); diff --git a/include/linux/pwm.h b/include/linux/pwm.h index cda3597b84f2..5c5c456948a4 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -93,8 +93,8 @@ struct pwm_device { * @state: state to fill with the current PWM state * * The returned PWM state represents the state that was applied by a previous call to - * pwm_apply_state(). Drivers may have to slightly tweak that state before programming it to - * hardware. If pwm_apply_state() was never called, this returns either the current hardware + * pwm_apply_might_sleep(). Drivers may have to slightly tweak that state before programming it to + * hardware. If pwm_apply_might_sleep() was never called, this returns either the current hardware * state (if supported) or the default settings. */ static inline void pwm_get_state(const struct pwm_device *pwm, @@ -158,20 +158,20 @@ static inline void pwm_get_args(const struct pwm_device *pwm, } /** - * pwm_init_state() - prepare a new state to be applied with pwm_apply_state() + * pwm_init_state() - prepare a new state to be applied with pwm_apply_might_sleep() * @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 + * to the PWM device with pwm_apply_might_sleep(). 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 function returns, you can adjust the ->enabled and ->duty_cycle - * fields according to your needs before calling pwm_apply_state(). + * fields according to your needs before calling pwm_apply_might_sleep(). * * ->duty_cycle is initially set to zero to avoid cases where the current * ->duty_cycle value exceed the pwm_args->period one, which would trigger - * an error if the user calls pwm_apply_state() without adjusting ->duty_cycle + * an error if the user calls pwm_apply_might_sleep() without adjusting ->duty_cycle * first. */ static inline void pwm_init_state(const struct pwm_device *pwm, @@ -227,7 +227,7 @@ pwm_get_relative_duty_cycle(const struct pwm_state *state, unsigned int scale) * * pwm_init_state(pwm, &state); * pwm_set_relative_duty_cycle(&state, 50, 100); - * pwm_apply_state(pwm, &state); + * pwm_apply_might_sleep(pwm, &state); * * This functions returns -EINVAL if @duty_cycle and/or @scale are * inconsistent (@scale == 0 or @duty_cycle > @scale). @@ -307,7 +307,7 @@ struct pwm_chip { #if IS_ENABLED(CONFIG_PWM) /* PWM user APIs */ -int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state); +int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state); int pwm_adjust_config(struct pwm_device *pwm); /** @@ -335,7 +335,7 @@ static inline int pwm_config(struct pwm_device *pwm, int duty_ns, state.duty_cycle = duty_ns; state.period = period_ns; - return pwm_apply_state(pwm, &state); + return pwm_apply_might_sleep(pwm, &state); } /** @@ -356,7 +356,7 @@ static inline int pwm_enable(struct pwm_device *pwm) return 0; state.enabled = true; - return pwm_apply_state(pwm, &state); + return pwm_apply_might_sleep(pwm, &state); } /** @@ -375,7 +375,7 @@ static inline void pwm_disable(struct pwm_device *pwm) return; state.enabled = false; - pwm_apply_state(pwm, &state); + pwm_apply_might_sleep(pwm, &state); } /* PWM provider APIs */ @@ -406,8 +406,8 @@ struct pwm_device *devm_fwnode_pwm_get(struct device *dev, struct fwnode_handle *fwnode, const char *con_id); #else -static inline int pwm_apply_state(struct pwm_device *pwm, - const struct pwm_state *state) +static inline int pwm_apply_might_sleep(struct pwm_device *pwm, + const struct pwm_state *state) { might_sleep(); return -ENOTSUPP; @@ -524,7 +524,7 @@ static inline void pwm_apply_args(struct pwm_device *pwm) state.period = pwm->args.period; state.usage_power = false; - pwm_apply_state(pwm, &state); + pwm_apply_might_sleep(pwm, &state); } struct pwm_lookup { From patchwork Wed Nov 29 09:13:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 13472471 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="CuHPQxsX"; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="doe8Ar56" Received: from gofer.mess.org (gofer.mess.org [IPv6:2a02:8011:d000:212::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E27B85; 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Wed, 29 Nov 2023 09:13:49 +0000 (GMT) From: Sean Young To: linux-media@vger.kernel.org, linux-pwm@vger.kernel.org, Ivaylo Dimitrov , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Jonathan Corbet Cc: Sean Young , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 2/4] pwm: make it possible to apply pwm changes in atomic context Date: Wed, 29 Nov 2023 09:13:35 +0000 Message-ID: <734c9985a6f54d34d9ef20203ba7f962b572cb45.1701248996.git.sean@mess.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Some pwm devices require sleeping, for example if the pwm device is connected over i2c. However, many pwm devices could be used from atomic context, e.g. memmory mapped pwm. This is useful for, for example, the pwm-ir-tx driver which requires precise timing. Sleeping causes havoc with the generated IR signal. Since not all pmw devices can support atomic context, we also add a pwm_is_atomic() function to check if it is supported. Signed-off-by: Sean Young --- Documentation/driver-api/pwm.rst | 9 +++++ drivers/pwm/core.c | 63 ++++++++++++++++++++++++++------ drivers/pwm/pwm-renesas-tpu.c | 1 - include/linux/pwm.h | 29 ++++++++++++++- 4 files changed, 87 insertions(+), 15 deletions(-) diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index f1d8197c8c43..1d4536fdf47c 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -43,6 +43,15 @@ After being requested, a PWM has to be configured using:: int pwm_apply_might_sleep(struct pwm_device *pwm, struct pwm_state *state); +Some PWM devices can be used from atomic context. You can check if this is +supported with:: + + bool pwm_is_atomic(struct pwm_device *pwm); + +If true, the PWM can be configured from atomic context with:: + + int pwm_apply_atomic(struct pwm_device *pwm, struct pwm_state *state); + This API controls both the PWM period/duty_cycle config and the enable/disable state. diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index fc92ba622e56..63174e207400 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -463,24 +463,15 @@ static void pwm_apply_debug(struct pwm_device *pwm, } /** - * pwm_apply_might_sleep() - atomically apply a new state to a PWM device + * pwm_apply_unchecked() - atomically apply a new state to a PWM device * @pwm: PWM device * @state: new state to apply */ -int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) +static int pwm_apply_unchecked(struct pwm_device *pwm, const struct pwm_state *state) { struct pwm_chip *chip; int err; - /* - * Some lowlevel driver's implementations of .apply() make use of - * mutexes, also with some drivers only returning when the new - * configuration is active calling pwm_apply_might_sleep() from atomic context - * is a bad idea. So make it explicit that calling this function might - * sleep. - */ - might_sleep(); - if (!pwm || !state || !state->period || state->duty_cycle > state->period) return -EINVAL; @@ -501,16 +492,64 @@ int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) pwm->state = *state; + return 0; +} + +/** + * pwm_apply_might_sleep() - atomically apply a new state to a PWM device + * Cannot be used in atomic context. + * @pwm: PWM device + * @state: new state to apply + */ +int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) +{ + int err; + + /* + * Some lowlevel driver's implementations of .apply() make use of + * mutexes, also with some drivers only returning when the new + * configuration is active calling pwm_apply_might_sleep() from atomic context + * is a bad idea. So make it explicit that calling this function might + * sleep. + */ + might_sleep(); + + if (IS_ENABLED(CONFIG_PWM_DEBUG) && pwm->chip->atomic) { + /* + * Catch any sleeping drivers when atomic is set. + */ + non_block_start(); + err = pwm_apply_unchecked(pwm, state); + non_block_end(); + } else { + err = pwm_apply_unchecked(pwm, 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; + return err; } EXPORT_SYMBOL_GPL(pwm_apply_might_sleep); +/** + * pwm_apply_atomic() - apply a new state to a PWM device from atomic context + * Not all pwm devices support this function, check with pwm_is_atomic(). + * @pwm: PWM device + * @state: new state to apply + */ +int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state) +{ + WARN_ONCE(!pwm->chip->atomic, + "sleeping pwm driver used in atomic context"); + + return pwm_apply_unchecked(pwm, state); +} +EXPORT_SYMBOL_GPL(pwm_apply_atomic); + /** * pwm_capture() - capture and report a PWM signal * @pwm: PWM device diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c index 4239f2c3e8b2..47ea92cd8c67 100644 --- a/drivers/pwm/pwm-renesas-tpu.c +++ b/drivers/pwm/pwm-renesas-tpu.c @@ -11,7 +11,6 @@ #include #include #include -#include #include #include #include diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 5c5c456948a4..f1fa1243e95a 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -286,6 +286,7 @@ struct pwm_ops { * @npwm: number of PWMs controlled by this chip * @of_xlate: request a PWM device given a device tree PWM specifier * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier + * @atomic: can the driver call pwm_apply_atomic in atomic context * @list: list node for internal use * @pwms: array of PWM devices allocated by the framework */ @@ -299,6 +300,7 @@ struct pwm_chip { struct pwm_device * (*of_xlate)(struct pwm_chip *chip, const struct of_phandle_args *args); unsigned int of_pwm_n_cells; + bool atomic; /* only used internally by the PWM framework */ struct list_head list; @@ -308,6 +310,7 @@ struct pwm_chip { #if IS_ENABLED(CONFIG_PWM) /* PWM user APIs */ int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state); +int pwm_apply_atomic(struct pwm_device *pwm, const struct pwm_state *state); int pwm_adjust_config(struct pwm_device *pwm); /** @@ -378,6 +381,17 @@ static inline void pwm_disable(struct pwm_device *pwm) pwm_apply_might_sleep(pwm, &state); } +/** + * pwm_is_atomic() - is pwm_apply_atomic() supported? + * @pwm: PWM device + * + * Returns: true pwm_apply_atomic() can be called from atomic context. + */ +static inline bool pwm_is_atomic(struct pwm_device *pwm) +{ + return pwm->chip->atomic; +} + /* PWM provider APIs */ int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, unsigned long timeout); @@ -406,16 +420,27 @@ struct pwm_device *devm_fwnode_pwm_get(struct device *dev, struct fwnode_handle *fwnode, const char *con_id); #else +static inline bool pwm_is_atomic(struct pwm_device *pwm) +{ + return false; +} + static inline int pwm_apply_might_sleep(struct pwm_device *pwm, const struct pwm_state *state) { might_sleep(); - return -ENOTSUPP; + return -EOPNOTSUPP; +} + +static inline int pwm_apply_atomic(struct pwm_device *pwm, + const struct pwm_state *state) +{ + return -EOPNOTSUPP; } static inline int pwm_adjust_config(struct pwm_device *pwm) { - return -ENOTSUPP; + return -EOPNOTSUPP; } static inline int pwm_config(struct pwm_device *pwm, int duty_ns, From patchwork Wed Nov 29 09:13:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 13472472 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="IFiTmvyg"; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="HZqr3Bk0" Received: from gofer.mess.org (gofer.mess.org [88.97.38.141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51F7B19BF; Wed, 29 Nov 2023 01:14:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1701249247; bh=GDt/QGFqEdFRkVDZgETPHCj6Jv9POqOqoTfpWoZLvRY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IFiTmvygiy0uzNbZVDFBQ+6YkB4Xw8LjiUtZdUXgHEvQAqNhQ6nXcUDTuacv9OEoM wSZAXPSkX4KeTFdv1eY5eLMfY5fCgz9kpbk4mrne8HWGqYdtEjBhQuXSR+kmEL8JbL OYTY2yT/ZcHpwSFpuylcaI3xSU9puvE16RMiEcPLOg2NZM/7C2XHypCniIcQKZulda a4Q1rlrXCekCFN1q5RVfPbVkEcCk5kqYr85CnPGQSxJIjEhWs7yzGx3/oRIOfqAoWi nIiwEeaBobENupOsD8kSyerYHWNj6XNxVrtNJAqqC3g/gzEr3YzAJ7yfH/JshpQHjV Lk4UY1PfxJBjQ== Received: by gofer.mess.org (Postfix, from userid 501) id 3EC8F10029D; Wed, 29 Nov 2023 09:14:07 +0000 (GMT) X-Spam-Level: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1701249229; bh=GDt/QGFqEdFRkVDZgETPHCj6Jv9POqOqoTfpWoZLvRY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HZqr3Bk07ZBh1TRRzsBJ3LgIh08ANfvAMRdGG3FuykyEvfE4w7BXktSqJKsP7UMLD kjfzaH7uM0BlNWPQuBXRLKAKfc+Cbzgdj0ywskPQsajoOu6SD0eTaEQe7wnunRxXqw brvA3SUE0eXFRXNBUjt+plaCy+58GmBy0Q9IH8aVNiveAilEtBnAVSoiAkDCxR4s3Q BR75PFAIDjXVMvLnvop57oIlOl7A4780cJeg71BPXSq34BDM2hIzgW3DbhTHcl8Ifk hq2HkyeLxjrpUXeoBc7DtaS31j+iZmJZ8XVLxSz3OxnEOvNivOg2hmp+rebjAfduD9 9KfTRtDJw8cGg== Received: from localhost.localdomain (bigcore-99.local [IPv6:2a02:8011:d000:212:ca7f:54ff:fe51:14d6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by gofer.mess.org (Postfix) with ESMTPSA id 49223100101; Wed, 29 Nov 2023 09:13:49 +0000 (GMT) From: Sean Young To: linux-media@vger.kernel.org, linux-pwm@vger.kernel.org, Ivaylo Dimitrov , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Florian Fainelli , Broadcom internal kernel review list , Ray Jui , Scott Branden Cc: Sean Young , linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 3/4] pwm: bcm2835: allow pwm driver to be used in atomic context Date: Wed, 29 Nov 2023 09:13:36 +0000 Message-ID: <179dc1ce85702a8b64b43c0e0df656b0c5e3ce30.1701248996.git.sean@mess.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 clk_get_rate() may do a mutex lock. Fetch the clock rate once, and prevent rate changes using clk_rate_exclusive_get(). Signed-off-by: Sean Young Reviewed-by: Florian Fainelli --- drivers/pwm/pwm-bcm2835.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 9777babd5b95..52748194a3da 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -28,6 +28,7 @@ struct bcm2835_pwm { struct device *dev; void __iomem *base; struct clk *clk; + unsigned long rate; }; static inline struct bcm2835_pwm *to_bcm2835_pwm(struct pwm_chip *chip) @@ -63,17 +64,11 @@ static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, { struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - unsigned long rate = clk_get_rate(pc->clk); unsigned long long period_cycles; u64 max_period; u32 val; - if (!rate) { - dev_err(pc->dev, "failed to get clock rate\n"); - return -EINVAL; - } - /* * period_cycles must be a 32 bit value, so period * rate / NSEC_PER_SEC * must be <= U32_MAX. As U32_MAX * NSEC_PER_SEC < U64_MAX the @@ -88,13 +83,13 @@ static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, * <=> period < ((U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC/2) / rate * <=> period <= ceil((U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC/2) / rate) - 1 */ - max_period = DIV_ROUND_UP_ULL((u64)U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC / 2, rate) - 1; + max_period = DIV_ROUND_UP_ULL((u64)U32_MAX * NSEC_PER_SEC + NSEC_PER_SEC / 2, pc->rate) - 1; if (state->period > max_period) return -EINVAL; /* set period */ - period_cycles = DIV_ROUND_CLOSEST_ULL(state->period * rate, NSEC_PER_SEC); + period_cycles = DIV_ROUND_CLOSEST_ULL(state->period * pc->rate, NSEC_PER_SEC); /* don't accept a period that is too small */ if (period_cycles < PERIOD_MIN) @@ -103,7 +98,7 @@ static int bcm2835_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, writel(period_cycles, pc->base + PERIOD(pwm->hwpwm)); /* set duty cycle */ - val = DIV_ROUND_CLOSEST_ULL(state->duty_cycle * rate, NSEC_PER_SEC); + val = DIV_ROUND_CLOSEST_ULL(state->duty_cycle * pc->rate, NSEC_PER_SEC); writel(val, pc->base + DUTY(pwm->hwpwm)); /* set polarity */ @@ -151,14 +146,29 @@ static int bcm2835_pwm_probe(struct platform_device *pdev) return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk), "clock not found\n"); + ret = clk_rate_exclusive_get(pc->clk); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "fail to get exclusive rate\n"); + + pc->rate = clk_get_rate(pc->clk); + if (!pc->rate) { + clk_rate_exclusive_put(pc->clk); + return dev_err_probe(&pdev->dev, -EINVAL, + "failed to get clock rate\n"); + } + pc->chip.dev = &pdev->dev; pc->chip.ops = &bcm2835_pwm_ops; + pc->chip.atomic = true; pc->chip.npwm = 2; ret = devm_pwmchip_add(&pdev->dev, &pc->chip); - if (ret < 0) + if (ret < 0) { + clk_rate_exclusive_put(pc->clk); return dev_err_probe(&pdev->dev, ret, "failed to add pwmchip\n"); + } return 0; } @@ -167,6 +177,7 @@ static int bcm2835_pwm_suspend(struct device *dev) { struct bcm2835_pwm *pc = dev_get_drvdata(dev); + clk_rate_exclusive_put(pc->clk); clk_disable_unprepare(pc->clk); return 0; From patchwork Wed Nov 29 09:13:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 13472473 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="sFslIrDj"; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="R8A9Ztle" Received: from gofer.mess.org (gofer.mess.org [IPv6:2a02:8011:d000:212::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A0421BCC; Wed, 29 Nov 2023 01:14:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1701249248; bh=86qGc+C1bzoMBqXYz1VUZShwwdjBHm4PTYqZtPorDr8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sFslIrDjvfJCb4xq3/T4HaSHgI9t55wNoziJAJYqxoR3/Hni0b4JfVemz/pNgInLZ V+ET98QqCmaJmgBqFnH+kuwYQBQafRArAGDWP4e4UHhrg9ULfyiiuPfQRoDsxVEwhr Cyo9Hzz+raiwciBrgZlNQ3pTaNPHDk5CzKXyNhfFKpAEt6vHlMm05648ktSLor4Dzr G72+xtM8RiGvRS1hqwWEkAuVDEq4dQCg5DtQcDEKbw3mY6V0mQ3Wmt6wgYJNIzFrbd 0idxXbyyWErrPaNSy/xgst9cudrs39V/G3rd4br09/wzz969pjy05TqSco6siI6xMn gFbvemiaicF7Q== Received: by gofer.mess.org (Postfix, from userid 501) id 2666F100101; Wed, 29 Nov 2023 09:14:08 +0000 (GMT) X-Spam-Level: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1701249229; bh=86qGc+C1bzoMBqXYz1VUZShwwdjBHm4PTYqZtPorDr8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R8A9ZtleLSz6m0a+Q7czGK5fLN87caTL/IXjRTkhfUMhdFa2IHcFcp3bZLf8SibVn +po2ohdU7NHZjN6wIgbWn0gjy388oRYlZKQonlG9d4T8wcwIC32i2WlHXHEoZTW5Wi pHk1tWk2AZwzdnV/MziLXAKskciCQPT010oQVgJ3nlJab6RQTHwl3UuDmE3gAtqvoX mXpgKjX+ypGABaLMRO/0atPtiXe2EXj1ZTvR2SJeLTKKCZXe6E9ZBx+Jrkd6UEXUwD C1sBdy9zY2uanEBfLcTVLWCaxm0DiBZjaqQ/YMwe6SjkVR3AaTsmCUOA/iKm2f8Ezs TT81Agosi5kdQ== Received: from localhost.localdomain (bigcore-99.local [IPv6:2a02:8011:d000:212:ca7f:54ff:fe51:14d6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by gofer.mess.org (Postfix) with ESMTPSA id 82A96100104; Wed, 29 Nov 2023 09:13:49 +0000 (GMT) From: Sean Young To: linux-media@vger.kernel.org, linux-pwm@vger.kernel.org, Ivaylo Dimitrov , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Sean Young , Mauro Carvalho Chehab Cc: linux-kernel@vger.kernel.org Subject: [PATCH v6 4/4] media: pwm-ir-tx: trigger edges from hrtimer interrupt context Date: Wed, 29 Nov 2023 09:13:37 +0000 Message-ID: <88fdb3a200989458c6f95c26fa9bb84c1e864798.1701248996.git.sean@mess.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This makes the generated IR much more precise. Before this change, the driver is unreliable and many users opted to use gpio-ir-tx instead. Signed-off-by: Sean Young --- drivers/media/rc/pwm-ir-tx.c | 79 ++++++++++++++++++++++++++++++++++-- 1 file changed, 76 insertions(+), 3 deletions(-) diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c index cf51e2760975..8575c4596d7b 100644 --- a/drivers/media/rc/pwm-ir-tx.c +++ b/drivers/media/rc/pwm-ir-tx.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include #include #define DRIVER_NAME "pwm-ir-tx" @@ -17,8 +19,14 @@ struct pwm_ir { struct pwm_device *pwm; - unsigned int carrier; - unsigned int duty_cycle; + struct hrtimer timer; + struct completion tx_done; + struct pwm_state *state; + u32 carrier; + u32 duty_cycle; + uint *txbuf; + uint txbuf_len; + uint txbuf_index; }; static const struct of_device_id pwm_ir_of_match[] = { @@ -82,6 +90,62 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, return count; } +static int pwm_ir_tx_atomic(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) +{ + struct pwm_ir *pwm_ir = dev->priv; + struct pwm_device *pwm = pwm_ir->pwm; + struct pwm_state state; + + pwm_init_state(pwm, &state); + + state.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier); + pwm_set_relative_duty_cycle(&state, pwm_ir->duty_cycle, 100); + + pwm_ir->txbuf = txbuf; + pwm_ir->txbuf_len = count; + pwm_ir->txbuf_index = 0; + pwm_ir->state = &state; + + hrtimer_start(&pwm_ir->timer, 0, HRTIMER_MODE_REL); + + wait_for_completion(&pwm_ir->tx_done); + + return count; +} + +static enum hrtimer_restart pwm_ir_timer(struct hrtimer *timer) +{ + struct pwm_ir *pwm_ir = container_of(timer, struct pwm_ir, timer); + ktime_t now; + + /* + * If we happen to hit an odd latency spike, loop through the + * pulses until we catch up. + */ + do { + u64 ns; + + pwm_ir->state->enabled = !(pwm_ir->txbuf_index % 2); + pwm_apply_atomic(pwm_ir->pwm, pwm_ir->state); + + if (pwm_ir->txbuf_index >= pwm_ir->txbuf_len) { + complete(&pwm_ir->tx_done); + + return HRTIMER_NORESTART; + } + + ns = US_TO_NS(pwm_ir->txbuf[pwm_ir->txbuf_index]); + hrtimer_add_expires_ns(timer, ns); + + pwm_ir->txbuf_index++; + + now = timer->base->get_time(); + } while (hrtimer_get_expires_tv64(timer) < now); + + return HRTIMER_RESTART; +} + static int pwm_ir_probe(struct platform_device *pdev) { struct pwm_ir *pwm_ir; @@ -103,10 +167,19 @@ static int pwm_ir_probe(struct platform_device *pdev) if (!rcdev) return -ENOMEM; + if (pwm_is_atomic(pwm_ir->pwm)) { + init_completion(&pwm_ir->tx_done); + hrtimer_init(&pwm_ir->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + pwm_ir->timer.function = pwm_ir_timer; + rcdev->tx_ir = pwm_ir_tx_atomic; + } else { + dev_info(&pdev->dev, "tx will not be accurate as pwm device does not support atomic mode"); + rcdev->tx_ir = pwm_ir_tx; + } + rcdev->priv = pwm_ir; rcdev->driver_name = DRIVER_NAME; rcdev->device_name = DEVICE_NAME; - rcdev->tx_ir = pwm_ir_tx; rcdev->s_tx_duty_cycle = pwm_ir_set_duty_cycle; rcdev->s_tx_carrier = pwm_ir_set_carrier;