[PATCH v9 11/12] drm: Add DP branch device info on debugfs

[Jim Bride]

On Fri, Sep 09, 2016 at 02:10:57PM +0300, Mika Kahola wrote:
> Read DisplayPort branch device info from through debugfs
> interface.
> 
> v2: use drm_dp_helper routines to collect data
> v3: cleanup to match the drm_dp_helper.c patches introduced
>     earlier in this series
> v4: move DP branch device info to function 'intel_dp_branch_device_info()'
> v5: initial step to move debugging info from intel_dp. to drm_dp_helper.c (Daniel)
> v6: read hw and sw revision without using specific drm_dp_helper routines
> v7: indentation fixes (Jim Bride)
> 
> Signed-off-by: Mika Kahola <mika.kahola at intel.com>

Reviewed-by: Jim Bride <jim.bride at linux.intel.com>

> ---
>  drivers/gpu/drm/drm_dp_helper.c     | 85 +++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_debugfs.c |  3 ++
>  include/drm/drm_dp_helper.h         |  2 +
>  3 files changed, 90 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 01ee7af..a536514 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -526,6 +526,91 @@ int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6])
>  }
>  EXPORT_SYMBOL(drm_dp_downstream_id);
>  
> +/**
> + * drm_dp_downstream_debug() - debug DP branch devices
> + * @m: pointer for debugfs file
> + * @dpcd: DisplayPort configuration data
> + * @port_cap: port capabilities
> + * @aux: DisplayPort AUX channel
> + *
> + */
> +void drm_dp_downstream_debug(struct seq_file *m,
> +			     const u8 dpcd[DP_RECEIVER_CAP_SIZE],
> +			     const u8 port_cap[4], struct drm_dp_aux *aux)
> +{
> +	bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> +				 DP_DETAILED_CAP_INFO_AVAILABLE;
> +	int clk;
> +	int bpc;
> +	char id[6];
> +	int len;
> +	uint8_t rev[2];
> +	int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
> +	bool branch_device = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> +			     DP_DWN_STRM_PORT_PRESENT;
> +
> +	seq_printf(m, "\tDP branch device present: %s\n",
> +		   branch_device ? "yes" : "no");
> +
> +	if (!branch_device)
> +		return;
> +
> +	switch (type) {
> +	case DP_DS_PORT_TYPE_DP:
> +		seq_puts(m, "\t\tType: DisplayPort\n");
> +		break;
> +	case DP_DS_PORT_TYPE_VGA:
> +		seq_puts(m, "\t\tType: VGA\n");
> +		break;
> +	case DP_DS_PORT_TYPE_DVI:
> +		seq_puts(m, "\t\tType: DVI\n");
> +		break;
> +	case DP_DS_PORT_TYPE_HDMI:
> +		seq_puts(m, "\t\tType: HDMI\n");
> +		break;
> +	case DP_DS_PORT_TYPE_NON_EDID:
> +		seq_puts(m, "\t\tType: others without EDID support\n");
> +		break;
> +	case DP_DS_PORT_TYPE_DP_DUALMODE:
> +		seq_puts(m, "\t\tType: DP++\n");
> +		break;
> +	case DP_DS_PORT_TYPE_WIRELESS:
> +		seq_puts(m, "\t\tType: Wireless\n");
> +		break;
> +	default:
> +		seq_puts(m, "\t\tType: N/A\n");
> +	}
> +
> +	drm_dp_downstream_id(aux, id);
> +	seq_printf(m, "\t\tID: %s\n", id);
> +
> +	len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1);
> +	if (len > 0)
> +		seq_printf(m, "\t\tHW: %d.%d\n",
> +			   (rev[0] & 0xf0) >> 4, rev[0] & 0xf);
> +
> +	len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, &rev, 2);
> +	if (len > 0)
> +		seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]);
> +
> +	if (detailed_cap_info) {
> +		clk = drm_dp_downstream_max_clock(dpcd, port_cap);
> +
> +		if (clk > 0) {
> +			if (type == DP_DS_PORT_TYPE_VGA)
> +				seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk);
> +			else
> +				seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk);
> +		}
> +
> +		bpc = drm_dp_downstream_max_bpc(dpcd, port_cap);
> +
> +		if (bpc > 0)
> +			seq_printf(m, "\t\tMax bpc: %d\n", bpc);
> +	}
> +}
> +EXPORT_SYMBOL(drm_dp_downstream_debug);
> +
>  /*
>   * I2C-over-AUX implementation
>   */
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 02b627e..44fab14 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2851,6 +2851,9 @@ static void intel_dp_info(struct seq_file *m,
>  	seq_printf(m, "\taudio support: %s\n", yesno(intel_dp->has_audio));
>  	if (intel_connector->base.connector_type == DRM_MODE_CONNECTOR_eDP)
>  		intel_panel_info(m, &intel_connector->panel);
> +
> +	drm_dp_downstream_debug(m, intel_dp->dpcd, intel_dp->downstream_ports,
> +				&intel_dp->aux);
>  }
>  
>  static void intel_hdmi_info(struct seq_file *m,
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 215202f..2a79882 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -823,6 +823,8 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
>  int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
>  			      const u8 port_cap[4]);
>  int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]);
> +void drm_dp_downstream_debug(struct seq_file *m, const u8 dpcd[DP_RECEIVER_CAP_SIZE],
> +			     const u8 port_cap[4], struct drm_dp_aux *aux);
>  
>  void drm_dp_aux_init(struct drm_dp_aux *aux);
>  int drm_dp_aux_register(struct drm_dp_aux *aux);
> -- 
> 2.7.4