[PATCH] drm/amd/display: add HDCP caps debugfs

[Bhawanpreet Lakha]

On 2020-02-24 4:15 p.m., Harry Wentland wrote:
>
> On 2020-02-24 2:55 p.m., Bhawanpreet Lakha wrote:
>> Add debugfs to get HDCP capability. This is also useful for
>> kms_content_protection igt test.
>>
>> Use:
>> 	cat /sys/kernel/debug/dri/0/DP-1/hdcp_sink_capability
>> 	cat /sys/kernel/debug/dri/0/HDMI-A-1/hdcp_sink_capability
>>
>> Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha at amd.com>
>> ---
>>   .../amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 61 +++++++++++++++++++
>>   1 file changed, 61 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>> index ead5c05eec92..52982c8c871f 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
>> @@ -815,6 +815,44 @@ static int vrr_range_show(struct seq_file *m, void *data)
>>   	return 0;
>>   }
>>   
>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>> +/*
>> + * Returns the HDCP capability of the Display (1.4 for now).
>> + *
>> + * NOTE* Not all HDMI displays report their HDCP caps even when they are capable.
>> + * Since its rare for a display to not be HDCP 1.4 capable, we set HDMI as always capable.
>> + *
>> + * Example usage: cat /sys/kernel/debug/dri/0/DP-1/hdcp_sink_capability
>> + *		or cat /sys/kernel/debug/dri/0/HDMI-A-1/hdcp_sink_capability
>> + */
>> +static int hdcp_sink_capability_show(struct seq_file *m, void *data)
>> +{
>> +	struct drm_connector *connector = m->private;
>> +	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
>> +	bool hdcp_cap, hdcp2_cap;
>> +
>> +	if (connector->status != connector_status_connected)
>> +		return -ENODEV;
>> +
>> +	seq_printf(m, "%s:%d HDCP version: ", connector->name, connector->base.id);
>> +
>> +	hdcp_cap = dc_link_is_hdcp14(aconnector->dc_link);
>> +	hdcp2_cap = dc_link_is_hdcp22(aconnector->dc_link);
>> +
>> +
>> +	if (hdcp_cap)
>> +		seq_printf(m, "%s ", "HDCP1.4");
>> +	if (hdcp2_cap)
>> +		seq_printf(m, "%s ", "HDCP2.2");
>> +
>> +	if (!hdcp_cap && !hdcp2_cap)
>> +		seq_printf(m, "%s ", "None");
>> +
>> +	seq_puts(m, "\n");
>> +
>> +	return 0;
>> +}
>> +#endif
>>   /* function description
>>    *
>>    * generic SDP message access for testing
>> @@ -940,6 +978,9 @@ static ssize_t dp_dpcd_data_read(struct file *f, char __user *buf,
>>   DEFINE_SHOW_ATTRIBUTE(dmub_tracebuffer);
>>   DEFINE_SHOW_ATTRIBUTE(output_bpc);
>>   DEFINE_SHOW_ATTRIBUTE(vrr_range);
>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>> +DEFINE_SHOW_ATTRIBUTE(hdcp_sink_capability);
>> +#endif
>>   
>>   static const struct file_operations dp_link_settings_debugfs_fops = {
>>   	.owner = THIS_MODULE,
>> @@ -995,12 +1036,23 @@ static const struct {
>>   		{"test_pattern", &dp_phy_test_pattern_fops},
>>   		{"output_bpc", &output_bpc_fops},
>>   		{"vrr_range", &vrr_range_fops},
>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>> +		{"hdcp_sink_capability", &hdcp_sink_capability_fops},
>> +#endif
>>   		{"sdp_message", &sdp_message_fops},
>>   		{"aux_dpcd_address", &dp_dpcd_address_debugfs_fops},
>>   		{"aux_dpcd_size", &dp_dpcd_size_debugfs_fops},
>>   		{"aux_dpcd_data", &dp_dpcd_data_debugfs_fops}
>>   };
>>   
>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>> +static const struct {
>> +	char *name;
>> +	const struct file_operations *fops;
>> +} hdmi_debugfs_entries[] = {
>> +		{"hdcp_sink_capability", &hdcp_sink_capability_fops}
>> +};
>> +#endif
>>   /*
>>    * Force YUV420 output if available from the given mode
>>    */
>> @@ -1066,6 +1118,15 @@ void connector_debugfs_init(struct amdgpu_dm_connector *connector)
>>   	debugfs_create_file_unsafe("force_yuv420_output", 0644, dir, connector,
>>   				   &force_yuv420_output_fops);
>>   
>> +#ifdef CONFIG_DRM_AMD_DC_HDCP
>> +	if (connector->base.connector_type == DRM_MODE_CONNECTOR_HDMIA) {
> Your patch description mentions DP and HDMI but here you're only
> creating it for HDMI. Should we create it for all HDCP-capable signal
> types, i.e. DP and HDMI?
>
> Harry

There is a loop above that is called for dp_debugfs_entries[]. I have 
added the HDCP debugfs to that struct so no need to recreate the loop.

Bhawan

>> +		for (i = 0; i < ARRAY_SIZE(hdmi_debugfs_entries); i++) {
>> +			debugfs_create_file(hdmi_debugfs_entries[i].name,
>> +					    0644, dir, connector,
>> +					    hdmi_debugfs_entries[i].fops);
>> +		}
>> +	}
>> +#endif
>>   }
>>   
>>   /*
>>