From 688eb4d465484bc2a3471a6a6f06f833b58c7867 Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:12 +0530 Subject: [PATCH 01/16] drm/bridge: cdns-dsi: Fix connecting to next bridge Fix the OF node pointer passed to the of_drm_find_bridge() call to find the next bridge in the display chain. The code to find the next panel (and create its panel-bridge) works fine, but to find the next (non-panel) bridge does not. To find the next bridge in the pipeline, we need to pass "np" - the OF node pointer of the next entity in the devicetree chain. Passing "of_node" to of_drm_find_bridge (which is what the code does currently) will fetch the bridge for the cdns-dsi which is not what's required. Fix that. Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver") Cc: stable@vger.kernel.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Tomi Valkeinen Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-2-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 99d43944fb8f..1cfe17865b06 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -966,7 +966,7 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host, bridge = drm_panel_bridge_add_typed(panel, DRM_MODE_CONNECTOR_DSI); } else { - bridge = of_drm_find_bridge(dev->dev.of_node); + bridge = of_drm_find_bridge(np); if (!bridge) bridge = ERR_PTR(-EINVAL); } -- 2.50.1 From fd2611c13f69cbbc6b81d9fc7502abf4f7031d21 Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:13 +0530 Subject: [PATCH 02/16] drm/bridge: cdns-dsi: Fix phy de-init and flag it so The driver code doesn't have a Phy de-initialization path as yet, and so it does not clear the phy_initialized flag while suspending. This is a problem because after resume the driver looks at this flag to determine if a Phy re-initialization is required or not. It is in fact required because the hardware is resuming from a suspend, but the driver does not carry out any re-initialization causing the D-Phy to not work at all. Call the counterparts of phy_init() and phy_power_on(), that are phy_exit() and phy_power_off(), from _bridge_post_disable(), and clear the flags so that the Phy can be initialized again when required. Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: stable@vger.kernel.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Tomi Valkeinen Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-3-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 1cfe17865b06..3b15528713fe 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -683,6 +683,11 @@ static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge, struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); struct cdns_dsi *dsi = input_to_dsi(input); + dsi->phy_initialized = false; + dsi->link_initialized = false; + phy_power_off(dsi->dphy); + phy_exit(dsi->dphy); + pm_runtime_put(dsi->base.dev); } @@ -1166,7 +1171,6 @@ static int __maybe_unused cdns_dsi_suspend(struct device *dev) clk_disable_unprepare(dsi->dsi_sys_clk); clk_disable_unprepare(dsi->dsi_p_clk); reset_control_assert(dsi->dsi_p_rst); - dsi->link_initialized = false; return 0; } -- 2.50.1 From 132bdcec399be6ae947582249a134b38cf56731c Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:14 +0530 Subject: [PATCH 03/16] drm/bridge: cdns-dsi: Fix the clock variable for mode_valid() The crtc_* mode parameters do not get generated (duplicated in this case) from the regular parameters before the mode validation phase begins. The rest of the code conditionally uses the crtc_* parameters only during the bridge enable phase, but sticks to the regular parameters for mode validation. In this singular instance, however, the driver tries to use the crtc_clock parameter even during the mode validation, causing the validation to fail. Allow the D-Phy config checks to use mode->clock instead of mode->crtc_clock during mode_valid checks, like everywhere else in the driver. Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: stable@vger.kernel.org Reviewed-by: Tomi Valkeinen Reviewed-by: Dmitry Baryshkov Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-4-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 3b15528713fe..02613ba7a05b 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -568,13 +568,14 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi, struct phy_configure_opts_mipi_dphy *phy_cfg = &output->phy_opts.mipi_dphy; unsigned long dsi_hss_hsa_hse_hbp; unsigned int nlanes = output->dev->lanes; + int mode_clock = (mode_valid_check ? mode->clock : mode->crtc_clock); int ret; ret = cdns_dsi_mode2cfg(dsi, mode, dsi_cfg, mode_valid_check); if (ret) return ret; - phy_mipi_dphy_get_default_config(mode->crtc_clock * 1000, + phy_mipi_dphy_get_default_config(mode_clock * 1000, mipi_dsi_pixel_format_to_bpp(output->dev->format), nlanes, phy_cfg); -- 2.50.1 From c6a7ef0d4856b9629df390e9935d7fd67fe39f81 Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:15 +0530 Subject: [PATCH 04/16] drm/bridge: cdns-dsi: Check return value when getting default PHY config Check for the return value of the phy_mipi_dphy_get_default_config() call, and in case of an error, return back the same. Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: stable@vger.kernel.org Reviewed-by: Tomi Valkeinen Reviewed-by: Dmitry Baryshkov Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-5-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 02613ba7a05b..741d676b8266 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -575,9 +575,11 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi, if (ret) return ret; - phy_mipi_dphy_get_default_config(mode_clock * 1000, - mipi_dsi_pixel_format_to_bpp(output->dev->format), - nlanes, phy_cfg); + ret = phy_mipi_dphy_get_default_config(mode_clock * 1000, + mipi_dsi_pixel_format_to_bpp(output->dev->format), + nlanes, phy_cfg); + if (ret) + return ret; ret = cdns_dsi_adjust_phy_config(dsi, dsi_cfg, phy_cfg, mode, mode_valid_check); if (ret) -- 2.50.1 From 47c03e6660e96cbba0239125b1d4a9db3c724b1d Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:16 +0530 Subject: [PATCH 05/16] drm/bridge: cdns-dsi: Wait for Clk and Data Lanes to be ready Once the DSI Link and DSI Phy are initialized, the code needs to wait for Clk and Data Lanes to be ready, before continuing configuration. This is in accordance with the DSI Start-up procedure, found in the Technical Reference Manual of Texas Instrument's J721E SoC[0] which houses this DSI TX controller. If the previous bridge (or crtc/encoder) are configured pre-maturely, the input signal FIFO gets corrupt. This introduces a color-shift on the display. Allow the driver to wait for the clk and data lanes to get ready during DSI enable. [0]: See section 12.6.5.7.3 "Start-up Procedure" in J721E SoC TRM TRM Link: http://www.ti.com/lit/pdf/spruil1 Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver") Cc: stable@vger.kernel.org Tested-by: Dominik Haller Reviewed-by: Tomi Valkeinen Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-6-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 741d676b8266..93c3d5f1651d 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -776,7 +776,7 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge, struct drm_connector *connector; unsigned long tx_byte_period; struct cdns_dsi_cfg dsi_cfg; - u32 tmp, reg_wakeup, div; + u32 tmp, reg_wakeup, div, status; int nlanes; if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0)) @@ -796,6 +796,19 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge, cdns_dsi_hs_init(dsi); cdns_dsi_init_link(dsi); + /* + * Now that the DSI Link and DSI Phy are initialized, + * wait for the CLK and Data Lanes to be ready. + */ + tmp = CLK_LANE_RDY; + for (int i = 0; i < nlanes; i++) + tmp |= DATA_LANE_RDY(i); + + if (readl_poll_timeout(dsi->regs + MCTL_MAIN_STS, status, + (tmp == (status & tmp)), 100, 500000)) + dev_err(dsi->base.dev, + "Timed Out: DSI-DPhy Clock and Data Lanes not ready.\n"); + writel(HBP_LEN(dsi_cfg.hbp) | HSA_LEN(dsi_cfg.hsa), dsi->regs + VID_HSIZE1); writel(HFP_LEN(dsi_cfg.hfp) | HACT_LEN(dsi_cfg.hact), -- 2.50.1 From 7ad8b3441b8ebfc56b439a28328f78c755bbef29 Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:17 +0530 Subject: [PATCH 06/16] drm/bridge: cdns-dsi: Move to devm_drm_of_get_bridge() Instead of manually finding the next bridge/panel, and maintaining the panel-bridge (in-case the next entity is a panel), switch to using the automatically managing devm_drm_of_get_bridge() API. Drop the drm_panel support completely from the driver while at it. Reviewed-by: Tomi Valkeinen Reviewed-by: Dmitry Baryshkov Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-7-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- .../gpu/drm/bridge/cadence/cdns-dsi-core.c | 28 ++----------------- .../gpu/drm/bridge/cadence/cdns-dsi-core.h | 2 -- 2 files changed, 3 insertions(+), 27 deletions(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 93c3d5f1651d..89a3f3efc522 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -955,8 +955,6 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host, struct cdns_dsi_output *output = &dsi->output; struct cdns_dsi_input *input = &dsi->input; struct drm_bridge *bridge; - struct drm_panel *panel; - struct device_node *np; int ret; /* @@ -974,26 +972,10 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host, /* * The host <-> device link might be described using an OF-graph * representation, in this case we extract the device of_node from - * this representation, otherwise we use dsidev->dev.of_node which - * should have been filled by the core. + * this representation. */ - np = of_graph_get_remote_node(dsi->base.dev->of_node, DSI_OUTPUT_PORT, - dev->channel); - if (!np) - np = of_node_get(dev->dev.of_node); - - panel = of_drm_find_panel(np); - if (!IS_ERR(panel)) { - bridge = drm_panel_bridge_add_typed(panel, - DRM_MODE_CONNECTOR_DSI); - } else { - bridge = of_drm_find_bridge(np); - if (!bridge) - bridge = ERR_PTR(-EINVAL); - } - - of_node_put(np); - + bridge = devm_drm_of_get_bridge(dsi->base.dev, dsi->base.dev->of_node, + DSI_OUTPUT_PORT, dev->channel); if (IS_ERR(bridge)) { ret = PTR_ERR(bridge); dev_err(host->dev, "failed to add DSI device %s (err = %d)", @@ -1003,7 +985,6 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host, output->dev = dev; output->bridge = bridge; - output->panel = panel; /* * The DSI output has been properly configured, we can now safely @@ -1019,12 +1000,9 @@ static int cdns_dsi_detach(struct mipi_dsi_host *host, struct mipi_dsi_device *dev) { struct cdns_dsi *dsi = to_cdns_dsi(host); - struct cdns_dsi_output *output = &dsi->output; struct cdns_dsi_input *input = &dsi->input; drm_bridge_remove(&input->bridge); - if (output->panel) - drm_panel_bridge_remove(output->bridge); return 0; } diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h index ca7ea2da635c..5db5dbbbcaad 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h @@ -10,7 +10,6 @@ #include #include -#include #include #include @@ -21,7 +20,6 @@ struct reset_control; struct cdns_dsi_output { struct mipi_dsi_device *dev; - struct drm_panel *panel; struct drm_bridge *bridge; union phy_configure_opts phy_opts; }; -- 2.50.1 From e83967c355d6194c906e7bb3f1c72cb002e14c9d Mon Sep 17 00:00:00 2001 From: Aradhya Bhatia Date: Sat, 29 Mar 2025 17:09:18 +0530 Subject: [PATCH 07/16] drm/mipi-dsi: Add helper to find input format Add a helper API that can be used by the DSI hosts to find the required input bus format for the given output dsi pixel format. Reviewed-by: Dmitry Baryshkov Reviewed-by: Tomi Valkeinen Tested-by: Tomi Valkeinen Signed-off-by: Aradhya Bhatia Signed-off-by: Aradhya Bhatia Link: https://lore.kernel.org/r/20250329113925.68204-8-aradhya.bhatia@linux.dev Signed-off-by: Dmitry Baryshkov --- drivers/gpu/drm/drm_mipi_dsi.c | 37 ++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 1 + 2 files changed, 38 insertions(+) diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index dfa595556320..e5184a0c2465 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -36,6 +36,8 @@ #include #include +#include + #include