Re: [PATCH v4] drm/bridge: ite-it6263: Move chip initialization code from probe to atomic_enable

[Liu Ying]

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> On the RZ/G3L SMARC EVK, suspend to RAM powers down the ITE IT6263 chip.
> The display controller driver's system PM callbacks invoke
> drm_mode_config_helper_{suspend,resume}, which in turn call the bridge's
> atomic_{disable,enable} callbacks to handle suspend/resume for the bridge
> without dedicated PM ops.
> 
> To support proper reinitialization after power loss, move reset_gpio into
> the it6263 struct so it is accessible beyond probe time. Relocate
> it6263_hw_reset(), it6263_lvds_set_i2c_addr(), it6263_lvds_config() and
> it6263_hdmi_config() from probe to atomic_enable, ensuring the chip is
> fully reset and reconfigured on every enable, including after a
> suspend/resume cycle.
> 
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
>
> diff --git a/drivers/gpu/drm/bridge/ite-it6263.c b/drivers/gpu/drm/bridge/ite-it6263.c
> index 2ea49245e700..4a8268d0eac2 100644
> --- a/drivers/gpu/drm/bridge/ite-it6263.c
> +++ b/drivers/gpu/drm/bridge/ite-it6263.c
> @@ -200,6 +200,7 @@ struct it6263 {
>  	struct regmap *lvds_regmap;
>  	struct drm_bridge bridge;
>  	struct drm_bridge *next_bridge;
> +	struct gpio_desc *reset_gpio;
>  	int lvds_data_mapping;
>  	bool lvds_dual_link;
>  	bool lvds_link12_swap;
> @@ -603,6 +604,15 @@ static void it6263_bridge_atomic_enable(struct drm_bridge *bridge,
>  	bool pclk_high;
>  	int i, ret;
>  
> +	it6263_hw_reset(it->reset_gpio);
> +
> +	ret = it6263_lvds_set_i2c_addr(it);
> +	if (ret)
> +		dev_err(it->dev, "failed to set I2C addr\n");
> +
> +	it6263_lvds_config(it);
> +	it6263_hdmi_config(it);
> +
>  	connector = drm_atomic_get_new_connector_for_encoder(state,
>  							     bridge->encoder);
>  	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
> @@ -838,7 +848,6 @@ static const struct drm_bridge_funcs it6263_bridge_funcs = {
>  static int it6263_probe(struct i2c_client *client)
>  {
>  	struct device *dev = &client->dev;
> -	struct gpio_desc *reset_gpio;
>  	struct it6263 *it;
>  	int ret;
>  
> @@ -856,9 +865,9 @@ static int it6263_probe(struct i2c_client *client)
>  		return dev_err_probe(dev, PTR_ERR(it->hdmi_regmap),
>  				     "failed to init I2C regmap for HDMI\n");
>  
> -	reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> -	if (IS_ERR(reset_gpio))
> -		return dev_err_probe(dev, PTR_ERR(reset_gpio),
> +	it->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(it->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(it->reset_gpio),
>  				     "failed to get reset gpio\n");
>  
>  	ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(it6263_supplies),
> @@ -870,12 +879,6 @@ static int it6263_probe(struct i2c_client *client)
>  	if (ret)
>  		return ret;
>  
> -	it6263_hw_reset(reset_gpio);
> -
> -	ret = it6263_lvds_set_i2c_addr(it);
> -	if (ret)
> -		return dev_err_probe(dev, ret, "failed to set I2C addr\n");
> -
>  	it->lvds_i2c = devm_i2c_new_dummy_device(dev, client->adapter,
>  						 LVDS_INPUT_CTRL_I2C_ADDR);
>  	if (IS_ERR(it->lvds_i2c))
> @@ -888,9 +891,6 @@ static int it6263_probe(struct i2c_client *client)
>  		return dev_err_probe(dev, PTR_ERR(it->lvds_regmap),
>  				     "failed to init I2C regmap for LVDS\n");
>  
> -	it6263_lvds_config(it);
> -	it6263_hdmi_config(it);
> -
>  	i2c_set_clientdata(client, it);
>  
>  	it->bridge.of_node = dev->of_node;

Reviewed-by: Liu Ying <victor.liu@xxxxxxx>

-- 
Regards,
Liu Ying