[Intel-gfx] [PATCH] drm/i915: Detect if MIPI panel based on VBT and initialize only if present

[Damien Lespiau]

On Fri, May 23, 2014 at 09:39:28PM +0530, Shobhit Kumar wrote:
> It seems by default the VBT has MIPI configuration block as well. The
> Generic driver will assume always MIPI if MIPI configuration block is found.
> This is causing probelm when actually there is eDP. Fix this by looking
> into general definition block which will have device configurations. From here
> we can figure out what is the LFP type and initialize MIPI only if MIPI
> is found.
> 
> Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h      |  2 ++
>  drivers/gpu/drm/i915/intel_bios.c    | 20 +++++++++++++++++++-
>  drivers/gpu/drm/i915/intel_display.c |  4 +++-
>  3 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 8e78703..5a5225b 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1229,7 +1229,9 @@ struct intel_vbt_data {
>  	} backlight;
>  
>  	/* MIPI DSI */
> +	int is_mipi;

There's a "feature" bitfield near the start of the structure, I think
you should add that field there and maybe rename it to has_mipi.

>  	struct {
> +		u16 port;

We store the port but never use it, is it needed?

>  		u16 panel_id;
>  		struct mipi_config *config;
>  		struct mipi_pps_data *pps;
> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> index 6b65096..b825c80 100644
> --- a/drivers/gpu/drm/i915/intel_bios.c
> +++ b/drivers/gpu/drm/i915/intel_bios.c
> @@ -1059,6 +1059,20 @@ parse_device_mapping(struct drm_i915_private *dev_priv,
>  			/* skip the device block if device type is invalid */
>  			continue;
>  		}
> +
> +#define MIPI_PORT_A	0x15
> +#define MIPI_PORT_B	0x16
> +#define MIPI_PORT_C	0x17
> +#define MIPI_PORT_D	0x18

These should go with the other valid defines for dvo_port in
intel_bios.h and be renamed to match, eg. DEVICE_PORT_MIPI_A.

Also this is not what I have in my copy of the VBT documentation, I have
(in decimal) MIPI PORT_A = 11, .., PORT_D = 14

> +		if (p_child->common.dvo_port >= MIPI_PORT_A && p_child->common.dvo_port <= MIPI_PORT_D) {
> +			/* check the device type and confirm its MIPI */
> +			if (p_child->common.device_type & DEVICE_TYPE_MIPI_OUTPUT) {
> +				DRM_DEBUG_KMS("Found MIPI as LFP\n");
> +				dev_priv->vbt.is_mipi = 1;
> +				dev_priv->vbt.dsi.port = p_child->common.dvo_port;
> +			}
> +		}
> +
>  		child_dev_ptr = dev_priv->vbt.child_dev + count;
>  		count++;
>  		memcpy((void *)child_dev_ptr, (void *)p_child,
> @@ -1230,7 +1244,11 @@ intel_parse_bios(struct drm_device *dev)
>  	parse_device_mapping(dev_priv, bdb);
>  	parse_driver_features(dev_priv, bdb);
>  	parse_edp(dev_priv, bdb);
> -	parse_mipi(dev_priv, bdb);
> +
> +	/* parse MIPI blocks only if LFP type is MIPI */
> +	if (dev_priv->vbt.is_mipi)
> +		parse_mipi(dev_priv, bdb);

Let's put that check inside parse_mipi so we don't break the symetry of
those parse_* calls.

> +
>  	parse_ddi_ports(dev_priv, bdb);
>  
>  	if (bios)
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 3da73ef..a55fa41 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -11151,7 +11151,9 @@ static void intel_setup_outputs(struct drm_device *dev)
>  			}
>  		}
>  
> -		intel_dsi_init(dev);
> +		/* There is no detection method for MIPI so rely on VBT */
> +		if (dev_priv->vbt.is_mipi)
> +			intel_dsi_init(dev);

Can we have that check inside intel_dsi_init() so we don't have to do it
for every platform with DSI?

>  	} else if (SUPPORTS_DIGITAL_OUTPUTS(dev)) {
>  		bool found = false;
>  
> -- 
> 1.8.3.2
>