Re: [PATCH v2 2/2] backlight: lm3630a: add an enable gpio for the HWEN pin

From: Daniel Thompson
Date: Wed Sep 11 2019 - 06:25:39 EST


On Tue, Sep 10, 2019 at 11:29:09PM +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@xxxxxxxxxxxx>
> ---
> changes in v2:
> - simplification
> - correct gpio direction initialisation
>
> drivers/video/backlight/lm3630a_bl.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/video/backlight/lm3630a_bl.c b/drivers/video/backlight/lm3630a_bl.c
> index 8f84f3684f04..9d0639d4202d 100644
> --- a/drivers/video/backlight/lm3630a_bl.c
> +++ b/drivers/video/backlight/lm3630a_bl.c
> @@ -12,6 +12,8 @@
> #include <linux/uaccess.h>
> #include <linux/interrupt.h>
> #include <linux/regmap.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/gpio.h>

Nitpicking... but I don't think linux/gpio.h is used anymore.


> #include <linux/pwm.h>
> #include <linux/platform_data/lm3630a_bl.h>
>
> @@ -48,6 +50,7 @@ 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 +538,13 @@ 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
>