From: allen chen <allen.c...@ite.com.tw>
Add driver to read data-lanes and link-frequencies from dt property to
restrict output bandwidth.
Signed-off-by: Allen chen <allen.c...@ite.com.tw>
Signed-off-by: Pin-yen Lin <treapk...@chromium.org>
---
drivers/gpu/drm/bridge/ite-it6505.c | 80 +++++++++++++++++++++++++++--
1 file changed, 77 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ite-it6505.c
b/drivers/gpu/drm/bridge/ite-it6505.c
index a4302492cf8df..ed4536cde3140 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -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;
@@ -1476,7 +1478,8 @@ 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",
@@ -2912,7 +2915,7 @@ 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;
@@ -3099,10 +3102,32 @@ 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");
@@ -3118,7 +3143,56 @@ 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,
--
2.25.1
