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From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Lee Jones <lee.jones@linaro.org>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Jingoo Han <jingoohan1@gmail.com>
Cc: linux-fbdev@vger.kernel.org,
	Thierry Reding <thierry.reding@gmail.com>,
	dri-devel@lists.freedesktop.org, kernel@pengutronix.de
Subject: [PATCH v3 2/2] backlight: lm3630a: convert to atomic PWM API and check for errors
Date: Mon, 21 Jun 2021 14:21:48 +0200	[thread overview]
Message-ID: <20210621122148.116863-3-u.kleine-koenig@pengutronix.de> (raw)
In-Reply-To: <20210621122148.116863-1-u.kleine-koenig@pengutronix.de>

The practical upside here is that this only needs a single API call to
program the hardware which (depending on the underlaying hardware) can
be more effective and prevents glitches.

Up to now the return value of the pwm functions was ignored. Fix this
and propagate the error to the caller.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/video/backlight/lm3630a_bl.c | 42 +++++++++++++---------------
 1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
index 7140b0d98082..f377dfdd9868 100644
--- a/drivers/video/backlight/lm3630a_bl.c
+++ b/drivers/video/backlight/lm3630a_bl.c
@@ -52,6 +52,7 @@ struct lm3630a_chip {
 	struct gpio_desc *enable_gpio;
 	struct regmap *regmap;
 	struct pwm_device *pwmd;
+	struct pwm_state pwmd_state;
 };
 
 /* i2c access */
@@ -167,16 +168,19 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 	return rval;
 }
 
-static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
+static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 {
-	unsigned int period = pchip->pdata->pwm_period;
-	unsigned int duty = br * period / br_max;
+	int err;
 
-	pwm_config(pchip->pwmd, duty, period);
-	if (duty)
-		pwm_enable(pchip->pwmd);
-	else
-		pwm_disable(pchip->pwmd);
+	pchip->pwmd_state.period = pchip->pdata->pwm_period;
+
+	err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max);
+	if (err)
+		return err;
+
+	pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false;
+
+	return pwm_apply_state(pchip->pwmd, &pchip->pwmd_state);
 }
 
 /* update and get brightness */
@@ -187,11 +191,9 @@ static int lm3630a_bank_a_update_status(struct backlight_device *bl)
 	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 
 	/* pwm control */
-	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
-		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
-				 bl->props.max_brightness);
-		return 0;
-	}
+	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0)
+		return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
+					bl->props.max_brightness);
 
 	/* disable sleep */
 	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
@@ -264,11 +266,9 @@ static int lm3630a_bank_b_update_status(struct backlight_device *bl)
 	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 
 	/* pwm control */
-	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
-		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
-				 bl->props.max_brightness);
-		return 0;
-	}
+	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
+		return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
+					bl->props.max_brightness);
 
 	/* disable sleep */
 	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
@@ -563,11 +563,7 @@ static int lm3630a_probe(struct i2c_client *client,
 			return PTR_ERR(pchip->pwmd);
 		}
 
-		/*
-		 * FIXME: pwm_apply_args() should be removed when switching to
-		 * the atomic PWM API.
-		 */
-		pwm_apply_args(pchip->pwmd);
+		pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
 	}
 
 	/* interrupt enable  : irq 0 is not allowed */
-- 
2.30.2


WARNING: multiple messages have this Message-ID
From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Lee Jones <lee.jones@linaro.org>,
	Daniel Thompson <daniel.thompson@linaro.org>,
	Jingoo Han <jingoohan1@gmail.com>
Cc: linux-fbdev@vger.kernel.org,
	Thierry Reding <thierry.reding@gmail.com>,
	kernel@pengutronix.de, dri-devel@lists.freedesktop.org
Subject: [PATCH v3 2/2] backlight: lm3630a: convert to atomic PWM API and check for errors
Date: Mon, 21 Jun 2021 14:21:48 +0200	[thread overview]
Message-ID: <20210621122148.116863-3-u.kleine-koenig@pengutronix.de> (raw)
In-Reply-To: <20210621122148.116863-1-u.kleine-koenig@pengutronix.de>

The practical upside here is that this only needs a single API call to
program the hardware which (depending on the underlaying hardware) can
be more effective and prevents glitches.

Up to now the return value of the pwm functions was ignored. Fix this
and propagate the error to the caller.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/video/backlight/lm3630a_bl.c | 42 +++++++++++++---------------
 1 file changed, 19 insertions(+), 23 deletions(-)

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
index 7140b0d98082..f377dfdd9868 100644
--- a/drivers/video/backlight/lm3630a_bl.c
+++ b/drivers/video/backlight/lm3630a_bl.c
@@ -52,6 +52,7 @@ struct lm3630a_chip {
 	struct gpio_desc *enable_gpio;
 	struct regmap *regmap;
 	struct pwm_device *pwmd;
+	struct pwm_state pwmd_state;
 };
 
 /* i2c access */
@@ -167,16 +168,19 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 	return rval;
 }
 
-static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
+static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 {
-	unsigned int period = pchip->pdata->pwm_period;
-	unsigned int duty = br * period / br_max;
+	int err;
 
-	pwm_config(pchip->pwmd, duty, period);
-	if (duty)
-		pwm_enable(pchip->pwmd);
-	else
-		pwm_disable(pchip->pwmd);
+	pchip->pwmd_state.period = pchip->pdata->pwm_period;
+
+	err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max);
+	if (err)
+		return err;
+
+	pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false;
+
+	return pwm_apply_state(pchip->pwmd, &pchip->pwmd_state);
 }
 
 /* update and get brightness */
@@ -187,11 +191,9 @@ static int lm3630a_bank_a_update_status(struct backlight_device *bl)
 	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 
 	/* pwm control */
-	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
-		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
-				 bl->props.max_brightness);
-		return 0;
-	}
+	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0)
+		return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
+					bl->props.max_brightness);
 
 	/* disable sleep */
 	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
@@ -264,11 +266,9 @@ static int lm3630a_bank_b_update_status(struct backlight_device *bl)
 	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 
 	/* pwm control */
-	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
-		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
-				 bl->props.max_brightness);
-		return 0;
-	}
+	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
+		return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
+					bl->props.max_brightness);
 
 	/* disable sleep */
 	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
@@ -563,11 +563,7 @@ static int lm3630a_probe(struct i2c_client *client,
 			return PTR_ERR(pchip->pwmd);
 		}
 
-		/*
-		 * FIXME: pwm_apply_args() should be removed when switching to
-		 * the atomic PWM API.
-		 */
-		pwm_apply_args(pchip->pwmd);
+		pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
 	}
 
 	/* interrupt enable  : irq 0 is not allowed */
-- 
2.30.2


  parent reply	other threads:[~2021-06-21 12:22 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-21 12:21 [PATCH v3 0/2] backlight: lm3630a: convert to atomic PWM API Uwe Kleine-König
2021-06-21 12:21 ` [PATCH v3 1/2] backlight: lm3630a: fix return code of .update_status() callback Uwe Kleine-König
2021-06-21 13:06   ` Daniel Thompson
2021-06-22 13:11   ` Lee Jones
2021-06-21 12:21 ` Uwe Kleine-König [this message]
2021-06-21 13:14   ` [PATCH v3 2/2] backlight: lm3630a: convert to atomic PWM API and check for errors Daniel Thompson
2021-06-22 13:12   ` Lee Jones
2021-06-24 20:10     ` Uwe Kleine-König
2021-06-25  8:44       ` Lee Jones

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