linux-kernel - Re: [PATCH v3 2/4] Input: goodix - Add AVDD28-supply regulator support

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Message-ID: <20190107230009.wfzozb6g6ucymngw@penguin>
Date:   Mon, 7 Jan 2019 23:00:09 +0000
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Jagan Teki <jagan@...rulasolutions.com>
Cc:     Chen-Yu Tsai <wens@...e.org>, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Michael Trimarchi <michael@...rulasolutions.com>,
        linux-amarula@...rulasolutions.com
Subject: Re: [PATCH v3 2/4] Input: goodix - Add AVDD28-supply regulator
 support

Hi Jagan,

On Sat, Dec 15, 2018 at 08:48:00PM +0530, Jagan Teki wrote:
> Goodix CTP controllers have AVDD28 pin connected to voltage
> regulator which may not be turned on by default, like for GT5663.
> 
> Add support for such ctp used boards by adding voltage regulator
> handling code to goodix ctp driver.
> 
> Signed-off-by: Jagan Teki <jagan@...rulasolutions.com>
> ---
>  drivers/input/touchscreen/goodix.c | 33 +++++++++++++++++++++++++-----
>  1 file changed, 28 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index f2d9c2c41885..7371f6946098 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -27,6 +27,7 @@
>  #include <linux/delay.h>
>  #include <linux/irq.h>
>  #include <linux/interrupt.h>
> +#include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
>  #include <linux/acpi.h>
>  #include <linux/of.h>
> @@ -47,6 +48,7 @@ struct goodix_ts_data {
>  	struct touchscreen_properties prop;
>  	unsigned int max_touch_num;
>  	unsigned int int_trigger_type;
> +	struct regulator *avdd28;
>  	struct gpio_desc *gpiod_int;
>  	struct gpio_desc *gpiod_rst;
>  	u16 id;
> @@ -786,25 +788,41 @@ static int goodix_ts_probe(struct i2c_client *client,
>  	if (error)
>  		return error;
>  
> +	ts->avdd28 = devm_regulator_get(&client->dev, "AVDD28");
> +	if (IS_ERR(ts->avdd28)) {
> +		error = PTR_ERR(ts->avdd28);
> +		if (error != -EPROBE_DEFER)
> +			dev_err(&client->dev,
> +				"Failed to get AVDD28 regulator: %d\n", error);
> +		return error;
> +	}
> +
> +	/* power the controller */
> +	error = regulator_enable(ts->avdd28);
> +	if (error) {
> +		dev_err(&client->dev, "Controller fail to enable AVDD28\n");
> +		return error;
> +	}
> +
>  	if (ts->gpiod_int && ts->gpiod_rst) {
>  		/* reset the controller */
>  		error = goodix_reset(ts);
>  		if (error) {
>  			dev_err(&client->dev, "Controller reset failed.\n");
> -			return error;
> +			goto error;
>  		}
>  	}
>  
>  	error = goodix_i2c_test(client);
>  	if (error) {
>  		dev_err(&client->dev, "I2C communication failure: %d\n", error);
> -		return error;
> +		goto error;
>  	}
>  
>  	error = goodix_read_version(ts);
>  	if (error) {
>  		dev_err(&client->dev, "Read version failed.\n");
> -		return error;
> +		goto error;
>  	}
>  
>  	ts->chip = goodix_get_chip_data(ts->id);
> @@ -823,23 +841,28 @@ static int goodix_ts_probe(struct i2c_client *client,
>  			dev_err(&client->dev,
>  				"Failed to invoke firmware loader: %d\n",
>  				error);
> -			return error;
> +			goto error;
>  		}
>  
>  		return 0;
>  	} else {
>  		error = goodix_configure_dev(ts);
>  		if (error)
> -			return error;
> +			goto error;
>  	}
>  
>  	return 0;
> +
> +error:
> +	regulator_disable(ts->avdd28);
> +	return error;
>  }
>  
>  static int goodix_ts_remove(struct i2c_client *client)
>  {
>  	struct goodix_ts_data *ts = i2c_get_clientdata(client);
>  
> +	regulator_disable(ts->avdd28);

This may be disabling the regulator too early. Please use
devm_add_action_or_reset() to install a custom devm handler that would
disable the regulator in line with the rest of devm unwinding flow.

>  	if (ts->gpiod_int && ts->gpiod_rst)
>  		wait_for_completion(&ts->firmware_loading_complete);
>  
> -- 
> 2.18.0.321.gffc6fa0e3
> 

Thanks.

-- 
Dmitry