Re: [RFC PATCH 06/17] drm/exynos: dsi: Handle exynos specifics via driver_data

[Sam Ravnborg <sam@ravnborg.org>]

On Sun, Jul 04, 2021 at 02:32:19PM +0530, Jagan Teki wrote:
> Exynos DSI driver is actually a Samsung MIPI DSIM bridge
> IP which is also used in i.MX8MM platforms.
> 
> Right now the existing driver has some exynos drm specific
> code bases like te_irq, crtc and component_ops.
> 
> In order to switch this driver into a common bridge driver
> We can see 2 options to handle the exynos specific code.
> 
> A. Drop the component_ops, and rework other specifics.
>    This may lead to more foundation work as it requires
>    more changes in exynos drm drivers stack.
> 
> B. Handle the exynos specifics via driver data, and make
>    the common bridge work in different platforms and plan
>    for option A in future.
> 
> So, this patch is trying to add option B) changes to handle
> exynos specifics via driver_data.

We really should find someone that has the time, energy, knowledge and
hardware that can include device_link support once anf for all for
bridges.
Then we would avoid hacks like this.

I see no other options at the moment, but look forward for a better
solution.

	Sam


> 
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c | 37 +++++++++++++++++++------
>  1 file changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> index 99a1b8c22313..53d878d4d2d7 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> @@ -250,6 +250,7 @@ struct exynos_dsi_driver_data {
>  	unsigned int wait_for_reset;
>  	unsigned int num_bits_resol;
>  	const unsigned int *reg_values;
> +	bool exynos_specific;
>  };
>  
>  struct exynos_dsi {
> @@ -459,6 +460,7 @@ static const struct exynos_dsi_driver_data exynos3_dsi_driver_data = {
>  	.wait_for_reset = 1,
>  	.num_bits_resol = 11,
>  	.reg_values = reg_values,
> +	.exynos_specific = true,
>  };
>  
>  static const struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
> @@ -471,6 +473,7 @@ static const struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
>  	.wait_for_reset = 1,
>  	.num_bits_resol = 11,
>  	.reg_values = reg_values,
> +	.exynos_specific = true,
>  };
>  
>  static const struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
> @@ -481,6 +484,7 @@ static const struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
>  	.wait_for_reset = 1,
>  	.num_bits_resol = 11,
>  	.reg_values = reg_values,
> +	.exynos_specific = true,
>  };
>  
>  static const struct exynos_dsi_driver_data exynos5433_dsi_driver_data = {
> @@ -492,6 +496,7 @@ static const struct exynos_dsi_driver_data exynos5433_dsi_driver_data = {
>  	.wait_for_reset = 0,
>  	.num_bits_resol = 12,
>  	.reg_values = exynos5433_reg_values,
> +	.exynos_specific = true,
>  };
>  
>  static const struct exynos_dsi_driver_data exynos5422_dsi_driver_data = {
> @@ -503,6 +508,7 @@ static const struct exynos_dsi_driver_data exynos5422_dsi_driver_data = {
>  	.wait_for_reset = 1,
>  	.num_bits_resol = 12,
>  	.reg_values = exynos5422_reg_values,
> +	.exynos_specific = true,
>  };
>  
>  static const struct of_device_id exynos_dsi_of_match[] = {
> @@ -1484,7 +1490,8 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
>  	 * If attached panel device is for command mode one, dsi should register
>  	 * TE interrupt handler.
>  	 */
> -	if (!(device->mode_flags & MIPI_DSI_MODE_VIDEO)) {
> +	if (dsi->driver_data->exynos_specific &&
> +	    !(device->mode_flags & MIPI_DSI_MODE_VIDEO)) {
>  		int ret = exynos_dsi_register_te_irq(dsi, &device->dev);
>  		if (ret)
>  			return ret;
> @@ -1495,8 +1502,9 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
>  	dsi->lanes = device->lanes;
>  	dsi->format = device->format;
>  	dsi->mode_flags = device->mode_flags;
> -	exynos_drm_crtc_get_by_type(drm, EXYNOS_DISPLAY_TYPE_LCD)->i80_mode =
> -			!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO);
> +	if (dsi->driver_data->exynos_specific)
> +		exynos_drm_crtc_get_by_type(drm, EXYNOS_DISPLAY_TYPE_LCD)->i80_mode =
> +					    !(dsi->mode_flags & MIPI_DSI_MODE_VIDEO);
>  
>  	mutex_unlock(&drm->mode_config.mutex);
>  
> @@ -1515,7 +1523,8 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,
>  	if (drm->mode_config.poll_enabled)
>  		drm_kms_helper_hotplug_event(drm);
>  
> -	exynos_dsi_unregister_te_irq(dsi);
> +	if (dsi->driver_data->exynos_specific)
> +		exynos_dsi_unregister_te_irq(dsi);
>  
>  	return 0;
>  }
> @@ -1737,6 +1746,15 @@ static int exynos_dsi_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	if (!dsi->driver_data->exynos_specific) {
> +		ret = mipi_dsi_host_register(&dsi->dsi_host);
> +		if (ret) {
> +			dev_err(dev, "failed to register mipi dsi host: %d\n",
> +				ret);
> +			return ret;
> +		}
> +	}
> +
>  	platform_set_drvdata(pdev, dsi);
>  
>  	pm_runtime_enable(dev);
> @@ -1747,9 +1765,11 @@ static int exynos_dsi_probe(struct platform_device *pdev)
>  
>  	drm_bridge_add(&dsi->bridge);
>  
> -	ret = component_add(dev, &exynos_dsi_component_ops);
> -	if (ret)
> -		goto err_disable_runtime;
> +	if (dsi->driver_data->exynos_specific) {
> +		ret = component_add(dev, &exynos_dsi_component_ops);
> +		if (ret)
> +			goto err_disable_runtime;
> +	}
>  
>  	return 0;
>  
> @@ -1767,7 +1787,8 @@ static int exynos_dsi_remove(struct platform_device *pdev)
>  
>  	pm_runtime_disable(&pdev->dev);
>  
> -	component_del(&pdev->dev, &exynos_dsi_component_ops);
> +	if (dsi->driver_data->exynos_specific)
> +		component_del(&pdev->dev, &exynos_dsi_component_ops);
>  
>  	return 0;
>  }
> -- 
> 2.25.1

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