[v3,2/2] backlight: lm3630a: add an enable gpio for the HWEN pin

Submitted by Andreas Kemnade on Sept. 11, 2019, 5:21 p.m.

Details

Message ID 20190911172106.12843-3-andreas@kemnade.info
State New
Headers show
Series "backlight_lm3630a: add enable_gpios property" ( rev: 1 ) in DRI devel

Not browsing as part of any series.

Commit Message

Andreas Kemnade Sept. 11, 2019, 5:21 p.m.
For now just enable it in the probe function to allow i2c
access. Disabling also means resetting the register values
to default and according to the datasheet does not give
power savings.

Tested on Kobo Clara HD.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
changes in v2:
- simplification
- correct gpio direction initialisation

changes in v3:
- removed legacy include

 drivers/video/backlight/lm3630a_bl.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
index 8f84f3684f04..d9e67b9b2571 100644
--- a/drivers/video/backlight/lm3630a_bl.c
+++ b/drivers/video/backlight/lm3630a_bl.c
@@ -12,6 +12,7 @@ 
 #include <linux/uaccess.h>
 #include <linux/interrupt.h>
 #include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
 #include <linux/pwm.h>
 #include <linux/platform_data/lm3630a_bl.h>
 
@@ -48,6 +49,7 @@  struct lm3630a_chip {
 	struct lm3630a_platform_data *pdata;
 	struct backlight_device *bleda;
 	struct backlight_device *bledb;
+	struct gpio_desc *enable_gpio;
 	struct regmap *regmap;
 	struct pwm_device *pwmd;
 };
@@ -535,6 +537,13 @@  static int lm3630a_probe(struct i2c_client *client,
 	}
 	pchip->pdata = pdata;
 
+	pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
+						GPIOD_OUT_HIGH);
+	if (IS_ERR(pchip->enable_gpio)) {
+		rval = PTR_ERR(pchip->enable_gpio);
+		return rval;
+	}
+
 	/* chip initialize */
 	rval = lm3630a_chip_init(pchip);
 	if (rval < 0) {

Comments

On Wed, Sep 11, 2019 at 07:21:06PM +0200, Andreas Kemnade wrote:
> For now just enable it in the probe function to allow i2c
> access. Disabling also means resetting the register values
> to default and according to the datasheet does not give
> power savings.
> 
> Tested on Kobo Clara HD.
> 
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>

Make sure Dan is happy w.r.t. his review comments but if this driver is
unchanged when you spin v4 (for the DT changes) then feel free to add:

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>


Daniel.

> ---
> changes in v2:
> - simplification
> - correct gpio direction initialisation
> 
> changes in v3:
> - removed legacy include
> 
>  drivers/video/backlight/lm3630a_bl.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
> index 8f84f3684f04..d9e67b9b2571 100644
> --- a/drivers/video/backlight/lm3630a_bl.c
> +++ b/drivers/video/backlight/lm3630a_bl.c
> @@ -12,6 +12,7 @@
>  #include <linux/uaccess.h>
>  #include <linux/interrupt.h>
>  #include <linux/regmap.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/pwm.h>
>  #include <linux/platform_data/lm3630a_bl.h>
>  
> @@ -48,6 +49,7 @@ struct lm3630a_chip {
>  	struct lm3630a_platform_data *pdata;
>  	struct backlight_device *bleda;
>  	struct backlight_device *bledb;
> +	struct gpio_desc *enable_gpio;
>  	struct regmap *regmap;
>  	struct pwm_device *pwmd;
>  };
> @@ -535,6 +537,13 @@ static int lm3630a_probe(struct i2c_client *client,
>  	}
>  	pchip->pdata = pdata;
>  
> +	pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
> +						GPIOD_OUT_HIGH);
> +	if (IS_ERR(pchip->enable_gpio)) {
> +		rval = PTR_ERR(pchip->enable_gpio);
> +		return rval;
> +	}
> +
>  	/* chip initialize */
>  	rval = lm3630a_chip_init(pchip);
>  	if (rval < 0) {
> -- 
> 2.20.1
>
Andreas

On 9/11/19 12:21 PM, Andreas Kemnade wrote:
> For now just enable it in the probe function to allow i2c
> access. Disabling also means resetting the register values
> to default and according to the datasheet does not give
> power savings.
>
> Tested on Kobo Clara HD.
>
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> ---
> changes in v2:
> - simplification
> - correct gpio direction initialisation
>
> changes in v3:
> - removed legacy include
>
>   drivers/video/backlight/lm3630a_bl.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
> index 8f84f3684f04..d9e67b9b2571 100644
> --- a/drivers/video/backlight/lm3630a_bl.c
> +++ b/drivers/video/backlight/lm3630a_bl.c
> @@ -12,6 +12,7 @@
>   #include <linux/uaccess.h>
>   #include <linux/interrupt.h>
>   #include <linux/regmap.h>
> +#include <linux/gpio/consumer.h>
>   #include <linux/pwm.h>
>   #include <linux/platform_data/lm3630a_bl.h>
>   
> @@ -48,6 +49,7 @@ struct lm3630a_chip {
>   	struct lm3630a_platform_data *pdata;
>   	struct backlight_device *bleda;
>   	struct backlight_device *bledb;
> +	struct gpio_desc *enable_gpio;
>   	struct regmap *regmap;
>   	struct pwm_device *pwmd;
>   };
> @@ -535,6 +537,13 @@ static int lm3630a_probe(struct i2c_client *client,
>   	}
>   	pchip->pdata = pdata;
>   
> +	pchip->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable",
> +						GPIOD_OUT_HIGH);
> +	if (IS_ERR(pchip->enable_gpio)) {
> +		rval = PTR_ERR(pchip->enable_gpio);
> +		return rval;
> +	}
> +
>   	/* chip initialize */
>   	rval = lm3630a_chip_init(pchip);
>   	if (rval < 0) {

Thanks for the explanation

It looks good to me

Reviewed-by: Dan Murphy <dmurphy@ti.com>