From 380d920b582d0f83852ac6885af868d93c38095b Mon Sep 17 00:00:00 2001 From: allen chen Date: Thu, 3 Nov 2022 17:12:43 +0800 Subject: [PATCH] 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: allen chen Signed-off-by: Pin-yen Lin Signed-off-by: Robert Foss 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 --- 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 dc57a98..9cda2df 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; @@ -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, -- 2.7.4