Unverified Commit 380d920b authored by allen chen's avatar allen chen Committed by Robert Foss
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drm/bridge: add it6505 driver to read data-lanes and link-frequencies from dt 



Add driver to read data-lanes and link-frequencies from dt property to
restrict output bandwidth.

Signed-off-by: default avatarallen chen <allen.chen@ite.com.tw>
Signed-off-by: default avatarPin-yen Lin <treapking@chromium.org>
Signed-off-by: default avatarRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103091243.96036-3-allen.chen@ite.com.tw
Link: https://patchwork.freedesktop.org/patch/msgid/20221103091243.96036-2-allen.chen@ite.com.tw
Link: https://patchwork.freedesktop.org/patch/msgid/20221103091243.96036-3-allen.chen@ite.com.tw
parent bc809594

drivers/gpu/drm/bridge/ite-it6505.c

+77 −3
Original line number Diff line number Diff line
@@ -437,6 +437,8 @@ struct it6505 { 
	bool powered;

	bool hpd_state;

	u32 afe_setting;

	u32 max_dpi_pixel_clock;

	u32 max_lane_count;

	enum hdcp_state hdcp_status;

	struct delayed_work hdcp_work;

	struct work_struct hdcp_wait_ksv_list;
@@ -1464,7 +1466,8 @@ static void it6505_parse_link_capabilities(struct it6505 *it6505) 
	it6505->lane_count = link->num_lanes;

	DRM_DEV_DEBUG_DRIVER(dev, "Sink support %d lanes training",

			     it6505->lane_count);

	it6505->lane_count = min_t(int, it6505->lane_count, MAX_LANE_COUNT);

	it6505->lane_count = min_t(int, it6505->lane_count,

				   it6505->max_lane_count);



	it6505->branch_device = drm_dp_is_branch(it6505->dpcd);

	DRM_DEV_DEBUG_DRIVER(dev, "Sink %sbranch device",
@@ -2907,7 +2910,7 @@ it6505_bridge_mode_valid(struct drm_bridge *bridge, 
	if (mode->flags & DRM_MODE_FLAG_INTERLACE)

		return MODE_NO_INTERLACE;



	if (mode->clock > DPI_PIXEL_CLK_MAX)

	if (mode->clock > it6505->max_dpi_pixel_clock)

		return MODE_CLOCK_HIGH;



	it6505->video_info.clock = mode->clock;
@@ -3096,10 +3099,32 @@ static int it6505_init_pdata(struct it6505 *it6505) 
	return 0;

}



static int it6505_get_data_lanes_count(const struct device_node *endpoint,

				       const unsigned int min,

				       const unsigned int max)

{

	int ret;



	ret = of_property_count_u32_elems(endpoint, "data-lanes");

	if (ret < 0)

		return ret;



	if (ret < min || ret > max)

		return -EINVAL;



	return ret;

}



static void it6505_parse_dt(struct it6505 *it6505)

{

	struct device *dev = &it6505->client->dev;

	struct device_node *np = dev->of_node, *ep = NULL;

	int len;

	u64 link_frequencies;

	u32 data_lanes[4];

	u32 *afe_setting = &it6505->afe_setting;

	u32 *max_lane_count = &it6505->max_lane_count;

	u32 *max_dpi_pixel_clock = &it6505->max_dpi_pixel_clock;



	it6505->lane_swap_disabled =

		device_property_read_bool(dev, "no-laneswap");
@@ -3115,7 +3140,56 @@ static void it6505_parse_dt(struct it6505 *it6505) 
	} else {

		*afe_setting = 0;

	}

	DRM_DEV_DEBUG_DRIVER(dev, "using afe_setting: %d", *afe_setting);



	ep = of_graph_get_endpoint_by_regs(np, 1, 0);

	of_node_put(ep);



	if (ep) {

		len = it6505_get_data_lanes_count(ep, 1, 4);



		if (len > 0 && len != 3) {

			of_property_read_u32_array(ep, "data-lanes",

						   data_lanes, len);

			*max_lane_count = len;

		} else {

			*max_lane_count = MAX_LANE_COUNT;

			dev_err(dev, "error data-lanes, use default");

		}

	} else {

		*max_lane_count = MAX_LANE_COUNT;

		dev_err(dev, "error endpoint, use default");

	}



	ep = of_graph_get_endpoint_by_regs(np, 0, 0);

	of_node_put(ep);



	if (ep) {

		len = of_property_read_variable_u64_array(ep,

							  "link-frequencies",

							  &link_frequencies, 0,

							  1);

		if (len >= 0) {

			do_div(link_frequencies, 1000);

			if (link_frequencies > 297000) {

				dev_err(dev,

					"max pixel clock error, use default");

				*max_dpi_pixel_clock = DPI_PIXEL_CLK_MAX;

			} else {

				*max_dpi_pixel_clock = link_frequencies;

			}

		} else {

			dev_err(dev, "error link frequencies, use default");

			*max_dpi_pixel_clock = DPI_PIXEL_CLK_MAX;

		}

	} else {

		dev_err(dev, "error endpoint, use default");

		*max_dpi_pixel_clock = DPI_PIXEL_CLK_MAX;

	}



	DRM_DEV_DEBUG_DRIVER(dev, "using afe_setting: %u, max_lane_count: %u",

			     it6505->afe_setting, it6505->max_lane_count);

	DRM_DEV_DEBUG_DRIVER(dev, "using max_dpi_pixel_clock: %u kHz",

			     it6505->max_dpi_pixel_clock);

}



static ssize_t receive_timing_debugfs_show(struct file *file, char __user *buf,