[1/2] pwm: make it possible to apply pwm changes in atomic context

Message ID	1bd5241d584ceb4d6b731c4dc3203fb9686ee1d1.1696156485.git.sean@mess.org
State	Changes Requested
Headers	show Return-Path: <linux-pwm-owner@vger.kernel.org> From: Sean Young <sean@mess.org> To: Thierry Reding <thierry.reding@gmail.com>, =?utf-8?q?Uwe_Kleine-K=C3=B6n?= =?utf-8?q?ig?= <u.kleine-koenig@pengutronix.de>, Shawn Guo <shawnguo@kernel.org>, Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix Kernel Team <kernel@pengutronix.de>, Fabio Estevam <festevam@gmail.com>, NXP Linux Team <linux-imx@nxp.com>, Vladimir Zapolskiy <vz@mleia.com>, Conor Dooley <conor.dooley@microchip.com>, Daire McNamara <daire.mcnamara@microchip.com>, Palmer Dabbelt <palmer@dabbelt.com>, Paul Walmsley <paul.walmsley@sifive.com>, Fabrice Gasnier <fabrice.gasnier@foss.st.com>, Maxime Coquelin <mcoquelin.stm32@gmail.com>, Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Sean Young <sean@mess.org>, Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>, linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH 1/2] pwm: make it possible to apply pwm changes in atomic context Date: Sun, 1 Oct 2023 11:40:29 +0100 Message-ID: <1bd5241d584ceb4d6b731c4dc3203fb9686ee1d1.1696156485.git.sean@mess.org> In-Reply-To: <cover.1696156485.git.sean@mess.org> References: <cover.1696156485.git.sean@mess.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	[1/2] pwm: make it possible to apply pwm changes in atomic context \| expand [1/2] pwm: make it possible to apply pwm changes in atomic context [2/2] media: pwm-ir-tx: trigger edges from hrtimer interrupt context

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index dc66e3405bf5..d9679ae5b2be 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -505,7 +505,7 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) * is a bad idea. So make it explicit that calling this function might * sleep. */ - might_sleep(); + might_sleep_if(pwm_can_sleep(pwm)); if (!pwm || !state || !state->period || state->duty_cycle > state->period) diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c index b7c6045c5d08..b8b9392844e9 100644 --- a/drivers/pwm/pwm-fsl-ftm.c +++ b/drivers/pwm/pwm-fsl-ftm.c @@ -405,6 +405,7 @@ static int fsl_pwm_probe(struct platform_device *pdev) fpc->soc = of_device_get_match_data(&pdev->dev); fpc->chip.dev = &pdev->dev; + fpc->chip.can_sleep = true; base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(base)) diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c index 98ab65c89685..6fd579089240 100644 --- a/drivers/pwm/pwm-imx-tpm.c +++ b/drivers/pwm/pwm-imx-tpm.c @@ -365,6 +365,7 @@ static int pwm_imx_tpm_probe(struct platform_device *pdev) tpm->chip.dev = &pdev->dev; tpm->chip.ops = &imx_tpm_pwm_ops; + tpm->chip.can_sleep = true; /* get number of channels */ val = readl(tpm->base + PWM_IMX_TPM_PARAM); diff --git a/drivers/pwm/pwm-iqs620a.c b/drivers/pwm/pwm-iqs620a.c index 47b3141135f3..ebce9e06b32e 100644 --- a/drivers/pwm/pwm-iqs620a.c +++ b/drivers/pwm/pwm-iqs620a.c @@ -209,6 +209,7 @@ static int iqs620_pwm_probe(struct platform_device *pdev) iqs620_pwm->chip.dev = &pdev->dev; iqs620_pwm->chip.ops = &iqs620_pwm_ops; iqs620_pwm->chip.npwm = 1; + iqs620_pwm->chip.can_sleep = true; mutex_init(&iqs620_pwm->lock); diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c index 7a19a840bca5..e26fc18b5304 100644 --- a/drivers/pwm/pwm-lpc18xx-sct.c +++ b/drivers/pwm/pwm-lpc18xx-sct.c @@ -395,6 +395,7 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev) lpc18xx_pwm->chip.dev = &pdev->dev; lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops; lpc18xx_pwm->chip.npwm = LPC18XX_NUM_PWMS; + lpc18xx_pwm->chip.can_sleep = true; /* SCT counter must be in unify (32 bit) mode */ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG, diff --git a/drivers/pwm/pwm-microchip-core.c b/drivers/pwm/pwm-microchip-core.c index e7525c98105e..503b5b427d69 100644 --- a/drivers/pwm/pwm-microchip-core.c +++ b/drivers/pwm/pwm-microchip-core.c @@ -474,6 +474,7 @@ static int mchp_core_pwm_probe(struct platform_device *pdev) mchp_core_pwm->chip.dev = &pdev->dev; mchp_core_pwm->chip.ops = &mchp_core_pwm_ops; mchp_core_pwm->chip.npwm = 16; + mchp_core_pwm->chip.can_sleep = true; mchp_core_pwm->channel_enabled = readb_relaxed(mchp_core_pwm->base + MCHPCOREPWM_EN(0)); mchp_core_pwm->channel_enabled |= diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c index 4889fbd8a431..438abbb80daf 100644 --- a/drivers/pwm/pwm-omap-dmtimer.c +++ b/drivers/pwm/pwm-omap-dmtimer.c @@ -404,6 +404,7 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev) omap->chip.dev = &pdev->dev; omap->chip.ops = &pwm_omap_dmtimer_ops; omap->chip.npwm = 1; + omap->chip.can_sleep = true; mutex_init(&omap->mutex); diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 3038a68412a7..a47e21977e49 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -571,6 +571,7 @@ static int pca9685_pwm_probe(struct i2c_client *client) pca->chip.npwm = PCA9685_MAXCHAN + 1; pca->chip.dev = &client->dev; + pca->chip.can_sleep = true; ret = pwmchip_add(&pca->chip); if (ret < 0) diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c index d7311614c846..96797a33d8c6 100644 --- a/drivers/pwm/pwm-renesas-tpu.c +++ b/drivers/pwm/pwm-renesas-tpu.c @@ -11,7 +11,6 @@ #include <linux/init.h> #include <linux/ioport.h> #include <linux/module.h> -#include <linux/mutex.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> diff --git a/drivers/pwm/pwm-rz-mtu3.c b/drivers/pwm/pwm-rz-mtu3.c index a56cecb0e46e..6d874a2a8785 100644 --- a/drivers/pwm/pwm-rz-mtu3.c +++ b/drivers/pwm/pwm-rz-mtu3.c @@ -516,6 +516,7 @@ static int rz_mtu3_pwm_probe(struct platform_device *pdev) pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); rz_mtu3_pwm->chip.dev = &pdev->dev; + rz_mtu3_pwm->chip.can_sleep = true; ret = devm_add_action_or_reset(&pdev->dev, rz_mtu3_pwm_pm_disable, rz_mtu3_pwm); if (ret < 0) diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c index eabddb7c7820..5677ed6eb4d5 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -240,6 +240,7 @@ static int pwm_sifive_probe(struct platform_device *pdev) chip->dev = dev; chip->ops = &pwm_sifive_ops; chip->npwm = 4; + chip->can_sleep = true; ddata->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(ddata->regs)) diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index b1d1373648a3..de9fbd570104 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -643,6 +643,7 @@ static int sti_pwm_probe(struct platform_device *pdev) pc->chip.dev = dev; pc->chip.ops = &sti_pwm_ops; pc->chip.npwm = pc->cdata->pwm_num_devs; + pc->chip.can_sleep = true; ret = pwmchip_add(&pc->chip); if (ret < 0) { diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index 3d6be7749e23..cd408158e55b 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -636,6 +636,7 @@ static int stm32_pwm_probe(struct platform_device *pdev) priv->chip.dev = dev; priv->chip.ops = &stm32pwm_ops; priv->chip.npwm = stm32_pwm_detect_channels(priv); + priv->chip.can_sleep = true; ret = devm_pwmchip_add(dev, &priv->chip); if (ret < 0) diff --git a/drivers/pwm/pwm-twl-led.c b/drivers/pwm/pwm-twl-led.c index 8fb84b441853..9e71429ecaed 100644 --- a/drivers/pwm/pwm-twl-led.c +++ b/drivers/pwm/pwm-twl-led.c @@ -362,6 +362,7 @@ static int twl_pwmled_probe(struct platform_device *pdev) } twl->chip.dev = &pdev->dev; + twl->chip.can_sleep = true; mutex_init(&twl->mutex); diff --git a/drivers/pwm/pwm-twl.c b/drivers/pwm/pwm-twl.c index 86567add79db..bd08014fec44 100644 --- a/drivers/pwm/pwm-twl.c +++ b/drivers/pwm/pwm-twl.c @@ -356,6 +356,7 @@ static int twl_pwm_probe(struct platform_device *pdev) twl->chip.dev = &pdev->dev; twl->chip.npwm = 2; + twl->chip.can_sleep = true; mutex_init(&twl->mutex); diff --git a/include/linux/pwm.h b/include/linux/pwm.h index d2f9f690a9c1..c94894ffa4c4 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -287,6 +287,7 @@ struct pwm_ops { * @ops: callbacks for this PWM controller * @base: number of first PWM controlled by this chip * @npwm: number of PWMs controlled by this chip + * @can_sleep: can the driver sleep in pwm_apply_state * @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 * @list: list node for internal use @@ -297,6 +298,7 @@ struct pwm_chip { const struct pwm_ops *ops; int base; unsigned int npwm; + bool can_sleep; struct pwm_device * (*of_xlate)(struct pwm_chip *chip, const struct of_phandle_args *args); @@ -380,6 +382,18 @@ static inline void pwm_disable(struct pwm_device *pwm) pwm_apply_state(pwm, &state); } +/** + * pwm_can_sleep() - can a pwm driver sleep in pwm_apply_state() + * @pwm: PWM device + * + * Returns: true if the driver may sleep, false if pwm_apply_state() + * can be called from atomic context. + */ +static inline bool pwm_can_sleep(struct pwm_device *pwm) +{ + return pwm->chip->can_sleep; +} + /* PWM provider APIs */ int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, unsigned long timeout); @@ -411,7 +425,7 @@ struct pwm_device *devm_fwnode_pwm_get(struct device *dev, static inline int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) { - might_sleep(); + might_sleep_if(pwm_can_sleep(pwm)); return -ENOTSUPP; } @@ -423,19 +437,24 @@ static inline int pwm_adjust_config(struct pwm_device *pwm) static inline int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) { - might_sleep(); + might_sleep_if(pwm_can_sleep(pwm)); return -EINVAL; } static inline int pwm_enable(struct pwm_device *pwm) { - might_sleep(); + might_sleep_if(pwm_can_sleep(pwm)); return -EINVAL; } static inline void pwm_disable(struct pwm_device *pwm) { - might_sleep(); + might_sleep_if(pwm_can_sleep(pwm)); +} + +static inline bool pwm_can_sleep(struct pwm_device *pwm) +{ + return true; } static inline int pwm_capture(struct pwm_device *pwm,

[1/2] pwm: make it possible to apply pwm changes in atomic context

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