drm/msm/dsi: add support for dsi test pattern generator

During board bringups its useful to have a DSI test pattern
generator to isolate a DPU vs a DSI issue and focus on the relevant
hardware block.

To facilitate this, add an API which triggers the DSI controller
test pattern. The expected output is a rectangular checkered pattern.

This has been validated on a single DSI video mode panel by calling it
right after drm_panel_enable() which is also the ideal location to use
this as the DSI host and the panel have been initialized by then.

Further validation on dual DSI and command mode panel is pending.
If there are any fix ups needed for those, it shall be applied on top
of this change.

Changes in v2:
 - generate the new dsi.xml.h and update the bitfield names
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/1626922232-29105-2-git-send-email-abhinavk@codeaurora.orgReviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dsi/dsi.h

@@ -84,6 +84,7 @@ void msm_dsi_manager_setup_encoder(int id);
 int msm_dsi_manager_register(struct msm_dsi *msm_dsi);
 void msm_dsi_manager_unregister(struct msm_dsi *msm_dsi);
 bool msm_dsi_manager_validate_current_config(u8 id);
+void msm_dsi_manager_tpg_enable(void);
 
 /* msm dsi */
 static inline bool msm_dsi_device_connected(struct msm_dsi *msm_dsi)
@@ -148,6 +149,8 @@ int dsi_clk_init_6g_v2(struct msm_dsi_host *msm_host);
 int dsi_calc_clk_rate_v2(struct msm_dsi_host *msm_host, bool is_dual_dsi);
 int dsi_calc_clk_rate_6g(struct msm_dsi_host *msm_host, bool is_dual_dsi);
 void msm_dsi_host_snapshot(struct msm_disp_state *disp_state, struct mipi_dsi_host *host);
+void msm_dsi_host_test_pattern_en(struct mipi_dsi_host *host);
+
 /* dsi phy */
 struct msm_dsi_phy;
 struct msm_dsi_phy_shared_timings {

drivers/gpu/drm/msm/dsi/dsi_host.c

@@ -2505,3 +2505,64 @@ void msm_dsi_host_snapshot(struct msm_disp_state *disp_state, struct mipi_dsi_ho
 
 	pm_runtime_put_sync(&msm_host->pdev->dev);
 }
+
+static void msm_dsi_host_video_test_pattern_setup(struct msm_dsi_host *msm_host)
+{
+	u32 reg;
+
+	reg = dsi_read(msm_host, REG_DSI_TEST_PATTERN_GEN_CTRL);
+
+	dsi_write(msm_host, REG_DSI_TEST_PATTERN_GEN_VIDEO_INIT_VAL, 0xff);
+	/* draw checkered rectangle pattern */
+	dsi_write(msm_host, REG_DSI_TPG_MAIN_CONTROL,
+			DSI_TPG_MAIN_CONTROL_CHECKERED_RECTANGLE_PATTERN);
+	/* use 24-bit RGB test pttern */
+	dsi_write(msm_host, REG_DSI_TPG_VIDEO_CONFIG,
+			DSI_TPG_VIDEO_CONFIG_BPP(VIDEO_CONFIG_24BPP) |
+			DSI_TPG_VIDEO_CONFIG_RGB);
+
+	reg |= DSI_TEST_PATTERN_GEN_CTRL_VIDEO_PATTERN_SEL(VID_MDSS_GENERAL_PATTERN);
+	dsi_write(msm_host, REG_DSI_TEST_PATTERN_GEN_CTRL, reg);
+
+	DBG("Video test pattern setup done\n");
+}
+
+static void msm_dsi_host_cmd_test_pattern_setup(struct msm_dsi_host *msm_host)
+{
+	u32 reg;
+
+	reg = dsi_read(msm_host, REG_DSI_TEST_PATTERN_GEN_CTRL);
+
+	/* initial value for test pattern */
+	dsi_write(msm_host, REG_DSI_TEST_PATTERN_GEN_CMD_MDP_INIT_VAL0, 0xff);
+
+	reg |= DSI_TEST_PATTERN_GEN_CTRL_CMD_MDP_STREAM0_PATTERN_SEL(CMD_MDP_MDSS_GENERAL_PATTERN);
+
+	dsi_write(msm_host, REG_DSI_TEST_PATTERN_GEN_CTRL, reg);
+	/* draw checkered rectangle pattern */
+	dsi_write(msm_host, REG_DSI_TPG_MAIN_CONTROL2,
+			DSI_TPG_MAIN_CONTROL2_CMD_MDP0_CHECKERED_RECTANGLE_PATTERN);
+
+	DBG("Cmd test pattern setup done\n");
+}
+
+void msm_dsi_host_test_pattern_en(struct mipi_dsi_host *host)
+{
+	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+	bool is_video_mode = !!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO);
+	u32 reg;
+
+	if (is_video_mode)
+		msm_dsi_host_video_test_pattern_setup(msm_host);
+	else
+		msm_dsi_host_cmd_test_pattern_setup(msm_host);
+
+	reg = dsi_read(msm_host, REG_DSI_TEST_PATTERN_GEN_CTRL);
+	/* enable the test pattern generator */
+	dsi_write(msm_host, REG_DSI_TEST_PATTERN_GEN_CTRL, (reg | DSI_TEST_PATTERN_GEN_CTRL_EN));
+
+	/* for command mode need to trigger one frame from tpg */
+	if (!is_video_mode)
+		dsi_write(msm_host, REG_DSI_TEST_PATTERN_GEN_CMD_STREAM0_TRIGGER,
+				DSI_TEST_PATTERN_GEN_CMD_STREAM0_TRIGGER_SW_TRIGGER);
+}

drivers/gpu/drm/msm/dsi/dsi_manager.c

@@ -440,6 +440,19 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
 	return;
 }
 
+void msm_dsi_manager_tpg_enable(void)
+{
+	struct msm_dsi *m_dsi = dsi_mgr_get_dsi(DSI_0);
+	struct msm_dsi *s_dsi = dsi_mgr_get_dsi(DSI_1);
+
+	/* if dual dsi, trigger tpg on master first then slave */
+	if (m_dsi) {
+		msm_dsi_host_test_pattern_en(m_dsi->host);
+		if (IS_DUAL_DSI() && s_dsi)
+			msm_dsi_host_test_pattern_en(s_dsi->host);
+	}
+}
+
 static void dsi_mgr_bridge_enable(struct drm_bridge *bridge)
 {
 	int id = dsi_mgr_bridge_get_id(bridge);