Re: [PATCH v2] drm/bridge/synopsys: dsi: Allow VPG to be enabled via debugfs

[Philippe CORNU]

Hi Matt,
and many thanks for the patch.

Tested successfully by Yannick on STM32MP1 boards :-)

Tested-by: Yannick Fertrà <yannick.fertre@xxxxxx>
Reviewed-by: Philippe Cornu <philippe.cornu@xxxxxx>

Thank you,
Philippe :-)


On 4/30/19 10:17 AM, Matt Redfearn wrote:
> The Synopsys MIPI DSI IP contains a video test pattern generator which
> is helpful in debugging video timing with connected displays.
> Add a debugfs directory containing files which allow the VPG to be
> enabled and disabled, and its orientation to be changed.
> 
> Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>
> 
> ---
> 
> Changes in v2:
> - Ensure dw_mipi_dsi_video_mode_config() doesn't break without CONFIG_DEBUG_FS
> - Tidy up initialisation / tidy up of debugfs
> 
>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 47 +++++++++++++++++++
>   1 file changed, 47 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 0ee440216b8..bffeef7a6cc 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -10,6 +10,7 @@
>   
>   #include <linux/clk.h>
>   #include <linux/component.h>
> +#include <linux/debugfs.h>
>   #include <linux/iopoll.h>
>   #include <linux/module.h>
>   #include <linux/of_device.h>
> @@ -86,6 +87,8 @@
>   #define VID_MODE_TYPE_NON_BURST_SYNC_EVENTS	0x1
>   #define VID_MODE_TYPE_BURST			0x2
>   #define VID_MODE_TYPE_MASK			0x3
> +#define VID_MODE_VPG_ENABLE		BIT(16)
> +#define VID_MODE_VPG_HORIZONTAL		BIT(24)
>   
>   #define DSI_VID_PKT_SIZE		0x3c
>   #define VID_PKT_SIZE(p)			((p) & 0x3fff)
> @@ -234,6 +237,13 @@ struct dw_mipi_dsi {
>   	u32 format;
>   	unsigned long mode_flags;
>   
> +#ifdef CONFIG_DEBUG_FS
> +	struct dentry *debugfs;
> +
> +	bool vpg;
> +	bool vpg_horizontal;
> +#endif /* CONFIG_DEBUG_FS */
> +
>   	struct dw_mipi_dsi *master; /* dual-dsi master ptr */
>   	struct dw_mipi_dsi *slave; /* dual-dsi slave ptr */
>   
> @@ -525,6 +535,13 @@ static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
>   	else
>   		val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;
>   
> +#ifdef CONFIG_DEBUG_FS
> +	if (dsi->vpg) {
> +		val |= VID_MODE_VPG_ENABLE;
> +		val |= dsi->vpg_horizontal ? VID_MODE_VPG_HORIZONTAL : 0;
> +	}
> +#endif /* CONFIG_DEBUG_FS */
> +
>   	dsi_write(dsi, DSI_VID_MODE_CFG, val);
>   }
>   
> @@ -935,6 +952,33 @@ static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
>   	.attach	      = dw_mipi_dsi_bridge_attach,
>   };
>   
> +#ifdef CONFIG_DEBUG_FS
> +
> +static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi)
> +{
> +	dsi->debugfs = debugfs_create_dir(dev_name(dsi->dev), NULL);
> +	if (IS_ERR(dsi->debugfs)) {
> +		dev_err(dsi->dev, "failed to create debugfs root\n");
> +		return;
> +	}
> +
> +	debugfs_create_bool("vpg", 0660, dsi->debugfs, &dsi->vpg);
> +	debugfs_create_bool("vpg_horizontal", 0660, dsi->debugfs,
> +			    &dsi->vpg_horizontal);
> +}
> +
> +static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi)
> +{
> +	debugfs_remove_recursive(dsi->debugfs);
> +}
> +
> +#else
> +
> +static void dw_mipi_dsi_debugfs_init(struct dw_mipi_dsi *dsi) { }
> +static void dw_mipi_dsi_debugfs_remove(struct dw_mipi_dsi *dsi) { }
> +
> +#endif /* CONFIG_DEBUG_FS */
> +
>   static struct dw_mipi_dsi *
>   __dw_mipi_dsi_probe(struct platform_device *pdev,
>   		    const struct dw_mipi_dsi_plat_data *plat_data)
> @@ -1005,6 +1049,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   		clk_disable_unprepare(dsi->pclk);
>   	}
>   
> +	dw_mipi_dsi_debugfs_init(dsi);
>   	pm_runtime_enable(dev);
>   
>   	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
> @@ -1012,6 +1057,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
>   	ret = mipi_dsi_host_register(&dsi->dsi_host);
>   	if (ret) {
>   		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
> +		dw_mipi_dsi_debugfs_remove(dsi);
>   		return ERR_PTR(ret);
>   	}
>   
> @@ -1029,6 +1075,7 @@ static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>   	mipi_dsi_host_unregister(&dsi->dsi_host);
>   
>   	pm_runtime_disable(dsi->dev);
> +	dw_mipi_dsi_debugfs_remove(dsi);
>   }
>   
>   void dw_mipi_dsi_set_slave(struct dw_mipi_dsi *dsi, struct dw_mipi_dsi *slave)
>