diff mbox

[v4,02/11] drm: Read DP downstream port capabilities

Message ID 1465219753-3737-3-git-send-email-mika.kahola@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mika Kahola June 6, 2016, 1:29 p.m. UTC 
Read DisplayPort downstream port capabilities. Depending on
the DP port the capabilities are defined in length of 1 byte
or 4 bytes depending if the detailed capability information is
available.

Signed-off-by: Mika Kahola <mika.kahola@intel.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 27 +++++++++++++++++++++++++++
 include/drm/drm_dp_helper.h     |  3 +++
 2 files changed, 30 insertions(+)

Comments

kernel test robot June 6, 2016, 4 p.m. UTC | #1 
Hi,

[auto build test WARNING on drm/drm-next]
[also build test WARNING on v4.7-rc2 next-20160606]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Mika-Kahola/drm-i915-DP-branch-devices/20160606-213650
base:   git://people.freedesktop.org/~airlied/linux.git drm-next
reproduce: make htmldocs

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/i915/i915_irq.c:606: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: Excess function parameter 'dev' description in 'i915_enable_asle_pipestat'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: Excess function parameter 'dev' description in 'i915_reset_and_wakeup'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'fmt'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: Excess function parameter 'dev' description in 'i915_handle_error'
   include/drm/drm_crtc.h:374: warning: No description found for parameter 'mode_blob'
   include/drm/drm_crtc.h:789: warning: No description found for parameter 'name'
   include/drm/drm_crtc.h:1248: warning: No description found for parameter 'connector_id'
   include/drm/drm_crtc.h:1248: warning: No description found for parameter 'tile_blob_ptr'
   include/drm/drm_crtc.h:1287: warning: No description found for parameter 'rotation'
   include/drm/drm_crtc.h:1549: warning: No description found for parameter 'name'
   include/drm/drm_crtc.h:1549: warning: No description found for parameter 'mutex'
   include/drm/drm_crtc.h:1549: warning: No description found for parameter 'helper_private'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tile_idr'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'connector_ida'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'delayed_event'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'edid_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'dpms_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'path_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tile_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'plane_type_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'rotation_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_src_x'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_src_y'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_src_w'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_src_h'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_crtc_x'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_crtc_y'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_crtc_w'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_crtc_h'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_fb_id'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_crtc_id'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_active'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'prop_mode_id'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'dvi_i_subconnector_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'dvi_i_select_subconnector_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_subconnector_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_select_subconnector_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_mode_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_left_margin_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_right_margin_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_top_margin_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_bottom_margin_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_brightness_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_contrast_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_flicker_reduction_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_overscan_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_saturation_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'tv_hue_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'scaling_mode_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'aspect_ratio_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'dirty_info_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'suggested_x_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'suggested_y_property'
   include/drm/drm_crtc.h:2185: warning: No description found for parameter 'allow_fb_modifiers'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: No description found for parameter 'nonblock'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: Excess function parameter 'nonblocking' description in 'drm_atomic_helper_commit'
   drivers/gpu/drm/drm_atomic_helper.c:2946: warning: No description found for parameter 'start'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: No description found for parameter 'nonblock'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: Excess function parameter 'nonblocking' description in 'drm_atomic_helper_commit'
   drivers/gpu/drm/drm_atomic_helper.c:2946: warning: No description found for parameter 'start'
   drivers/gpu/drm/drm_atomic_helper.c:1: warning: no structured comments found
       Was looking for 'implementing async commit'.
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: No description found for parameter 'nonblock'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: Excess function parameter 'nonblocking' description in 'drm_atomic_helper_commit'
   drivers/gpu/drm/drm_atomic_helper.c:2946: warning: No description found for parameter 'start'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: No description found for parameter 'nonblock'
   drivers/gpu/drm/drm_atomic_helper.c:1150: warning: Excess function parameter 'nonblocking' description in 'drm_atomic_helper_commit'
   drivers/gpu/drm/drm_atomic_helper.c:2946: warning: No description found for parameter 'start'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'dev'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'file_priv'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'mode_cmd'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'funcs'
   drivers/gpu/drm/drm_fb_cma_helper.c:233: warning: No description found for parameter 'dev'
   drivers/gpu/drm/drm_fb_cma_helper.c:233: warning: No description found for parameter 'file_priv'
   drivers/gpu/drm/drm_fb_cma_helper.c:233: warning: No description found for parameter 'mode_cmd'
   drivers/gpu/drm/drm_fb_cma_helper.c:285: warning: No description found for parameter 'm'
   drivers/gpu/drm/drm_fb_cma_helper.c:285: warning: No description found for parameter 'arg'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'dev'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'file_priv'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'mode_cmd'
   drivers/gpu/drm/drm_fb_cma_helper.c:173: warning: No description found for parameter 'funcs'
   drivers/gpu/drm/drm_fb_cma_helper.c:233: warning: No description found for parameter 'dev'
   drivers/gpu/drm/drm_fb_cma_helper.c:233: warning: No description found for parameter 'file_priv'
   drivers/gpu/drm/drm_fb_cma_helper.c:233: warning: No description found for parameter 'mode_cmd'
   drivers/gpu/drm/drm_fb_cma_helper.c:285: warning: No description found for parameter 'm'
   drivers/gpu/drm/drm_fb_cma_helper.c:285: warning: No description found for parameter 'arg'
>> drivers/gpu/drm/drm_dp_helper.c:451: warning: No description found for parameter 'aux'
   include/drm/drm_dp_helper.h:753: warning: No description found for parameter 'i2c_nack_count'
   include/drm/drm_dp_helper.h:753: warning: No description found for parameter 'i2c_defer_count'
>> drivers/gpu/drm/drm_dp_helper.c:451: warning: No description found for parameter 'aux'
   drivers/gpu/drm/drm_dp_mst_topology.c:2383: warning: No description found for parameter 'connector'
   include/drm/drm_dp_mst_helper.h:92: warning: No description found for parameter 'cached_edid'
   include/drm/drm_dp_mst_helper.h:92: warning: No description found for parameter 'has_audio'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'max_dpcd_transaction_bytes'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'sink_count'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'total_slots'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'avail_slots'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'total_pbn'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'qlock'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'tx_msg_downq'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'tx_down_in_progress'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'payload_lock'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'proposed_vcpis'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'payloads'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'payload_mask'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'vcpi_mask'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'tx_waitq'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'work'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'tx_work'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'destroy_connector_list'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'destroy_connector_lock'
   include/drm/drm_dp_mst_helper.h:466: warning: No description found for parameter 'destroy_connector_work'
   drivers/gpu/drm/drm_dp_mst_topology.c:2383: warning: No description found for parameter 'connector'
   drivers/gpu/drm/drm_irq.c:158: warning: No description found for parameter 'flags'
   include/drm/drmP.h:169: warning: No description found for parameter 'fmt'
   include/drm/drmP.h:185: warning: No description found for parameter 'fmt'
   include/drm/drmP.h:203: warning: No description found for parameter 'fmt'
   include/drm/drmP.h:248: warning: No description found for parameter 'dev'
   include/drm/drmP.h:248: warning: No description found for parameter 'data'
   include/drm/drmP.h:248: warning: No description found for parameter 'file_priv'
   include/drm/drmP.h:281: warning: No description found for parameter 'ioctl'
   include/drm/drmP.h:281: warning: No description found for parameter '_func'
   include/drm/drmP.h:281: warning: No description found for parameter '_flags'
   include/drm/drmP.h:363: warning: cannot understand function prototype: 'struct drm_lock_data '
   include/drm/drmP.h:411: warning: cannot understand function prototype: 'struct drm_driver '
   include/drm/drmP.h:677: warning: cannot understand function prototype: 'struct drm_info_list '
   include/drm/drmP.h:687: warning: cannot understand function prototype: 'struct drm_info_node '
   include/drm/drmP.h:697: warning: cannot understand function prototype: 'struct drm_minor '
   include/drm/drmP.h:745: warning: cannot understand function prototype: 'struct drm_device '
   drivers/gpu/drm/i915/intel_runtime_pm.c:2416: warning: No description found for parameter 'resume'
   drivers/gpu/drm/i915/intel_runtime_pm.c:2416: warning: No description found for parameter 'resume'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: Excess function parameter 'dev' description in 'i915_enable_asle_pipestat'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: Excess function parameter 'dev' description in 'i915_reset_and_wakeup'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'fmt'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: Excess function parameter 'dev' description in 'i915_handle_error'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: Excess function parameter 'dev' description in 'i915_enable_asle_pipestat'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: Excess function parameter 'dev' description in 'i915_reset_and_wakeup'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'fmt'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: Excess function parameter 'dev' description in 'i915_handle_error'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: Excess function parameter 'dev' description in 'i915_enable_asle_pipestat'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: Excess function parameter 'dev' description in 'i915_reset_and_wakeup'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'fmt'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: Excess function parameter 'dev' description in 'i915_handle_error'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:606: warning: Excess function parameter 'dev' description in 'i915_enable_asle_pipestat'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2538: warning: Excess function parameter 'dev' description in 'i915_reset_and_wakeup'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: No description found for parameter 'fmt'
   drivers/gpu/drm/i915/i915_irq.c:2700: warning: Excess function parameter 'dev' description in 'i915_handle_error'
   drivers/gpu/drm/i915/i915_vgpu.c:62: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_vgpu.c:62: warning: Excess function parameter 'dev' description in 'i915_check_vgpu'
   drivers/gpu/drm/i915/i915_vgpu.c:181: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_vgpu.c:181: warning: Excess function parameter 'dev_priv' description in 'intel_vgt_balloon'
   drivers/gpu/drm/i915/i915_vgpu.c:62: warning: No description found for parameter 'dev_priv'
   drivers/gpu/drm/i915/i915_vgpu.c:62: warning: Excess function parameter 'dev' description in 'i915_check_vgpu'
   drivers/gpu/drm/i915/i915_vgpu.c:181: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_vgpu.c:181: warning: Excess function parameter 'dev_priv' description in 'intel_vgt_balloon'
   drivers/gpu/drm/i915/i915_gem.c:416: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_gem.c:416: warning: No description found for parameter 'data'
   drivers/gpu/drm/i915/i915_gem.c:416: warning: No description found for parameter 'file'
   drivers/gpu/drm/i915/i915_gem.c:681: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_gem.c:681: warning: No description found for parameter 'data'
   drivers/gpu/drm/i915/i915_gem.c:681: warning: No description found for parameter 'file'
   drivers/gpu/drm/i915/i915_gem.c:762: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_gem.c:762: warning: No description found for parameter 'obj'
   drivers/gpu/drm/i915/i915_gem.c:762: warning: No description found for parameter 'args'
   drivers/gpu/drm/i915/i915_gem.c:762: warning: No description found for parameter 'file'
   drivers/gpu/drm/i915/i915_gem.c:1025: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_gem.c:1025: warning: No description found for parameter 'data'
   drivers/gpu/drm/i915/i915_gem.c:1025: warning: No description found for parameter 'file'
   drivers/gpu/drm/i915/i915_gem.c:1231: warning: No description found for parameter 'rps'
   drivers/gpu/drm/i915/i915_gem.c:1452: warning: No description found for parameter 'req'
   drivers/gpu/drm/i915/i915_gem.c:1479: warning: No description found for parameter 'obj'
   drivers/gpu/drm/i915/i915_gem.c:1479: warning: No description found for parameter 'readonly'
   drivers/gpu/drm/i915/i915_gem.c:1596: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_gem.c:1596: warning: No description found for parameter 'data'
   drivers/gpu/drm/i915/i915_gem.c:1596: warning: No description found for parameter 'file'
   drivers/gpu/drm/i915/i915_gem.c:1659: warning: No description found for parameter 'dev'
   drivers/gpu/drm/i915/i915_gem.c:1659: warning: No description found for parameter 'data'
   drivers/gpu/drm/i915/i915_gem.c:1659: warning: No description found for parameter 'file'

vim +/aux +451 drivers/gpu/drm/drm_dp_helper.c

   435			return err;
   436	
   437		return 0;
   438	}
   439	EXPORT_SYMBOL(drm_dp_link_configure);
   440	
   441	/**
   442	 * drm_dp_downstream_port_cap() - read downstream port capabilities
   443	 * @dpcd: DisplayPort configuration data
   444	 * @port_cap: port capabilities
   445	 *
   446	 * returns size of the port capabilites
   447	 */
   448	int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
   449				       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
   450				       u8 port_cap[4])
 > 451	{
   452		int size;
   453		bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
   454			DP_DETAILED_CAP_INFO_AVAILABLE;
   455	
   456		if (detailed_cap_info) {
   457			size = 4;
   458			drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, port_cap, size);
   459		} else {

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Ville Syrjälä June 9, 2016, 7:52 a.m. UTC | #2 
On Mon, Jun 06, 2016 at 04:29:04PM +0300, Mika Kahola wrote:
> Read DisplayPort downstream port capabilities. Depending on
> the DP port the capabilities are defined in length of 1 byte
> or 4 bytes depending if the detailed capability information is
> available.
> 
> Signed-off-by: Mika Kahola <mika.kahola@intel.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 27 +++++++++++++++++++++++++++
>  include/drm/drm_dp_helper.h     |  3 +++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index eeaf5a7..c4149fd 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -438,6 +438,33 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
>  }
>  EXPORT_SYMBOL(drm_dp_link_configure);
>  
> +/**
> + * drm_dp_downstream_port_cap() - read downstream port capabilities
> + * @dpcd: DisplayPort configuration data
> + * @port_cap: port capabilities
> + *
> + * returns size of the port capabilites
> + */
> +int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
> +			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
> +			       u8 port_cap[4])
> +{
> +	int size;
> +	bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
> +		DP_DETAILED_CAP_INFO_AVAILABLE;
> +
> +	if (detailed_cap_info) {
> +		size = 4;
> +		drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, port_cap, size);
> +	} else {
> +		size = 1;
> +		drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, &port_cap[0], size);
> +	}

Could avoid a bit of duplicatetion. Eg.:
	if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE)
		size = 4;
	else
		size = 1;

	return drm_dp_dpcd_read(...);

Though perhaps we should just read out the entire 4/16 bytes to get the
caps for all the ports?

> +
> +	return size;
> +}
> +EXPORT_SYMBOL(drm_dp_downstream_port_cap);
> +
>  /*
>   * I2C-over-AUX implementation
>   */
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index e384c7f..db8d3d47 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -806,6 +806,9 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
>  int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
>  int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link);
>  int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
> +int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
> +			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
> +			       u8 port_cap[4]);
>  
>  int drm_dp_aux_register(struct drm_dp_aux *aux);
>  void drm_dp_aux_unregister(struct drm_dp_aux *aux);
> -- 
> 1.9.1
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index eeaf5a7..c4149fd 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -438,6 +438,33 @@  int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link)
 }
 EXPORT_SYMBOL(drm_dp_link_configure);
 
+/**
+ * drm_dp_downstream_port_cap() - read downstream port capabilities
+ * @dpcd: DisplayPort configuration data
+ * @port_cap: port capabilities
+ *
+ * returns size of the port capabilites
+ */
+int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
+			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			       u8 port_cap[4])
+{
+	int size;
+	bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+		DP_DETAILED_CAP_INFO_AVAILABLE;
+
+	if (detailed_cap_info) {
+		size = 4;
+		drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, port_cap, size);
+	} else {
+		size = 1;
+		drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, &port_cap[0], size);
+	}
+
+	return size;
+}
+EXPORT_SYMBOL(drm_dp_downstream_port_cap);
+
 /*
  * I2C-over-AUX implementation
  */
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index e384c7f..db8d3d47 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -806,6 +806,9 @@  int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link);
 int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
+int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
+			       const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+			       u8 port_cap[4]);
 
 int drm_dp_aux_register(struct drm_dp_aux *aux);
 void drm_dp_aux_unregister(struct drm_dp_aux *aux);