linux-kernel - Re: [PATCH v3 2/2] input: touchscreen: goodix: Hold controller in reset during suspend

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Message-ID: <33b72957-1062-1b66-85eb-c37dc5ca259b@redhat.com>
Date:   Sun, 12 Mar 2023 19:59:03 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Jan Jasper de Kroon <jajadekroon@...il.com>
Cc:     linux-input@...r.kernel.org, megi@....cz, hadess@...ess.net,
        dmitry.torokhov@...il.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/2] input: touchscreen: goodix: Hold controller in
 reset during suspend

Hi,

On 3/12/23 19:40, Jan Jasper de Kroon wrote:
> From: Ondřej Jirman <megi@....cz>
> 
> The Goodix touchscreen controller used in PinePhone is not properly
> suspended during system sleep, leading to high power consumption. This
> commit modifies the driver to hold the controller in reset during
> system sleep, reducing power consumption by around 40mW.
> 
> The original patch also disabled the regulators during system sleep, but
> this could cause issues with other peripherals attached to the same power
> supplies. Hence, this commit only holds the controller in reset during
> system sleep and does not attempt to power it off.
> 
> Separate commit adds a new device tree property "hold-in-reset-in-suspend"
> to control the hold-in-reset behavior of the controller during system
> sleep.
> 
> Signed-off-by: Ondřej Jirman <megi@....cz>
> Signed-off-by: Jan Jasper de Kroon <jajadekroon@...il.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@...hat.com>

Regards,

Hans



> ---
> V1 -> V2: 
> - Rewrote the commit message and function name to better reflect it's 
>   behavior.
> v2 -> V3: Some patch style cleaning up, to confirm to submission standard.
> 
>  drivers/input/touchscreen/goodix.c | 23 +++++++++++++++++++++++
>  drivers/input/touchscreen/goodix.h |  1 +
>  2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
> index b348172f19c3..a35a203e04bf 100644
> --- a/drivers/input/touchscreen/goodix.c
> +++ b/drivers/input/touchscreen/goodix.c
> @@ -1284,6 +1284,7 @@ static void goodix_disable_regulators(void *arg)
>  
>  static int goodix_ts_probe(struct i2c_client *client)
>  {
> +	struct device_node *np = client->dev.of_node;
>  	struct goodix_ts_data *ts;
>  	const char *cfg_name;
>  	int error;
> @@ -1303,6 +1304,7 @@ static int goodix_ts_probe(struct i2c_client *client)
>  	i2c_set_clientdata(client, ts);
>  	init_completion(&ts->firmware_loading_complete);
>  	ts->contact_size = GOODIX_CONTACT_SIZE;
> +	ts->hold_in_reset_in_suspend = of_property_read_bool(np, "hold-in-reset-in-suspend");
>  
>  	error = goodix_get_gpio_config(ts);
>  	if (error)
> @@ -1410,6 +1412,13 @@ static int goodix_suspend(struct device *dev)
>  	if (ts->load_cfg_from_disk)
>  		wait_for_completion(&ts->firmware_loading_complete);
>  
> +	if (ts->hold_in_reset_in_suspend) {
> +		goodix_free_irq(ts);
> +		goodix_irq_direction_output(ts, 0);
> +		gpiod_direction_output(ts->gpiod_rst, 0);
> +		return 0;
> +	}
> +
>  	/* We need gpio pins to suspend/resume */
>  	if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_NONE) {
>  		disable_irq(client->irq);
> @@ -1455,6 +1464,20 @@ static int goodix_resume(struct device *dev)
>  	u8 config_ver;
>  	int error;
>  
> +	if (ts->hold_in_reset_in_suspend) {
> +		error = goodix_reset(ts);
> +		if (error) {
> +			dev_err(dev, "Controller reset failed.\n");
> +			return error;
> +		}
> +
> +		error = goodix_request_irq(ts);
> +		if (error)
> +			return error;
> +
> +		return 0;
> +	}
> +
>  	if (ts->irq_pin_access_method == IRQ_PIN_ACCESS_NONE) {
>  		enable_irq(client->irq);
>  		return 0;
> diff --git a/drivers/input/touchscreen/goodix.h b/drivers/input/touchscreen/goodix.h
> index 87797cc88b32..c515d03b742c 100644
> --- a/drivers/input/touchscreen/goodix.h
> +++ b/drivers/input/touchscreen/goodix.h
> @@ -104,6 +104,7 @@ struct goodix_ts_data {
>  	u8 main_clk[GOODIX_MAIN_CLK_LEN];
>  	int bak_ref_len;
>  	u8 *bak_ref;
> +	bool hold_in_reset_in_suspend;
>  };
>  
>  int goodix_i2c_read(struct i2c_client *client, u16 reg, u8 *buf, int len);