[PATCH 2/2] drm/bridge: add it6505 driver to read data-lanes and max-pixel-clock-khz from dt

allen
2022-09-13T08:49:07Z

Add driver to read data-lanes and max-pixel-clock-khz from dt property
to restrict output bandwidth.

Signed-off-by: Allen chen <allen.chen@ite.com.tw>
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
---
drivers/gpu/drm/bridge/ite-it6505.c | 35 ++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 2767b70fa2cb..cfa25a176a29 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -436,6 +436,8 @@ 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;
@@ -1475,7 +1477,8 @@ 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",
@@ -2901,7 +2904,7 @@ 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;
@@ -3066,6 +3069,8 @@ static void it6505_parse_dt(struct it6505 *it6505)
{
struct device *dev = &it6505->client->dev;
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");
@@ -3081,7 +3086,31 @@ static void it6505_parse_dt(struct it6505 *it6505)
} else {
*afe_setting = 0;
}
- DRM_DEV_DEBUG_DRIVER(dev, "using afe_setting: %d", *afe_setting);
+
+ if (device_property_read_u32(dev, "data-lanes",
+ max_lane_count) == 0) {
+ if (*max_lane_count > 4 || *max_lane_count == 3) {
+ dev_err(dev, "max lane count error, use default");
+ *max_lane_count = MAX_LANE_COUNT;
+ }
+ } else {
+ *max_lane_count = MAX_LANE_COUNT;
+ }
+
+ if (device_property_read_u32(dev, "max-pixel-clock-khz",
+ max_dpi_pixel_clock) == 0) {
+ if (*max_dpi_pixel_clock > 297000) {
+ dev_err(dev, "max pixel clock error, use default");
+ *max_dpi_pixel_clock = DPI_PIXEL_CLK_MAX;
+ }
+ } else {
+ *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