1 files changed, 127 insertions, 156 deletions

diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
index b022dd6e6b6e..09b289f0fcbf 100644
--- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
+++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
@@ -9,6 +9,7 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_probe_helper.h>
 #include <video/mipi_display.h>
+#include <video/videomode.h>
 
 #include <linux/clk.h>
 #include <linux/interrupt.h>
@@ -417,7 +418,8 @@
 #define DSI_OUTPUT_PORT			0
 #define DSI_INPUT_PORT(inputid)		(1 + (inputid))
 
-#define DSI_HBP_FRAME_OVERHEAD		12
+#define DSI_HBP_FRAME_PULSE_OVERHEAD	12
+#define DSI_HBP_FRAME_EVENT_OVERHEAD	16
 #define DSI_HSA_FRAME_OVERHEAD		14
 #define DSI_HFP_FRAME_OVERHEAD		6
 #define DSI_HSS_VSS_VSE_FRAME_OVERHEAD	4
@@ -452,15 +454,6 @@ bridge_to_cdns_dsi_input(struct drm_bridge *bridge)
 	return container_of(bridge, struct cdns_dsi_input, bridge);
 }
 
-static unsigned int mode_to_dpi_hfp(const struct drm_display_mode *mode,
-				    bool mode_valid_check)
-{
-	if (mode_valid_check)
-		return mode->hsync_start - mode->hdisplay;
-
-	return mode->crtc_hsync_start - mode->crtc_hdisplay;
-}
-
 static unsigned int dpi_to_dsi_timing(unsigned int dpi_timing,
 				      unsigned int dpi_bpp,
 				      unsigned int dsi_pkt_overhead)
@@ -476,145 +469,77 @@ static unsigned int dpi_to_dsi_timing(unsigned int dpi_timing,
 }
 
 static int cdns_dsi_mode2cfg(struct cdns_dsi *dsi,
-			     const struct drm_display_mode *mode,
-			     struct cdns_dsi_cfg *dsi_cfg,
-			     bool mode_valid_check)
+			     const struct videomode *vm,
+			     struct cdns_dsi_cfg *dsi_cfg)
 {
 	struct cdns_dsi_output *output = &dsi->output;
-	unsigned int tmp;
-	bool sync_pulse = false;
+	u32 dpi_hsa, dpi_hbp, dpi_hfp, dpi_hact;
+	bool sync_pulse;
 	int bpp;
 
+	dpi_hsa = vm->hsync_len;
+	dpi_hbp = vm->hback_porch;
+	dpi_hfp = vm->hfront_porch;
+	dpi_hact = vm->hactive;
+
 	memset(dsi_cfg, 0, sizeof(*dsi_cfg));
 
-	if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
-		sync_pulse = true;
+	sync_pulse = output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
 
 	bpp = mipi_dsi_pixel_format_to_bpp(output->dev->format);
 
-	if (mode_valid_check)
-		tmp = mode->htotal -
-		      (sync_pulse ? mode->hsync_end : mode->hsync_start);
-	else
-		tmp = mode->crtc_htotal -
-		      (sync_pulse ?
-		       mode->crtc_hsync_end : mode->crtc_hsync_start);
-
-	dsi_cfg->hbp = dpi_to_dsi_timing(tmp, bpp, DSI_HBP_FRAME_OVERHEAD);
-
 	if (sync_pulse) {
-		if (mode_valid_check)
-			tmp = mode->hsync_end - mode->hsync_start;
-		else
-			tmp = mode->crtc_hsync_end - mode->crtc_hsync_start;
+		dsi_cfg->hbp = dpi_to_dsi_timing(dpi_hbp, bpp,
+						 DSI_HBP_FRAME_PULSE_OVERHEAD);
 
-		dsi_cfg->hsa = dpi_to_dsi_timing(tmp, bpp,
+		dsi_cfg->hsa = dpi_to_dsi_timing(dpi_hsa, bpp,
 						 DSI_HSA_FRAME_OVERHEAD);
-	}
+	} else {
+		dsi_cfg->hbp = dpi_to_dsi_timing(dpi_hbp + dpi_hsa, bpp,
+						 DSI_HBP_FRAME_EVENT_OVERHEAD);
 
-	dsi_cfg->hact = dpi_to_dsi_timing(mode_valid_check ?
-					  mode->hdisplay : mode->crtc_hdisplay,
-					  bpp, 0);
-	dsi_cfg->hfp = dpi_to_dsi_timing(mode_to_dpi_hfp(mode, mode_valid_check),
-					 bpp, DSI_HFP_FRAME_OVERHEAD);
-
-	return 0;
-}
-
-static int cdns_dsi_adjust_phy_config(struct cdns_dsi *dsi,
-			      struct cdns_dsi_cfg *dsi_cfg,
-			      struct phy_configure_opts_mipi_dphy *phy_cfg,
-			      const struct drm_display_mode *mode,
-			      bool mode_valid_check)
-{
-	struct cdns_dsi_output *output = &dsi->output;
-	unsigned long long dlane_bps;
-	unsigned long adj_dsi_htotal;
-	unsigned long dsi_htotal;
-	unsigned long dpi_htotal;
-	unsigned long dpi_hz;
-	unsigned int dsi_hfp_ext;
-	unsigned int lanes = output->dev->lanes;
-
-	dsi_htotal = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
-	if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
-		dsi_htotal += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
-
-	dsi_htotal += dsi_cfg->hact;
-	dsi_htotal += dsi_cfg->hfp + DSI_HFP_FRAME_OVERHEAD;
-
-	/*
-	 * Make sure DSI htotal is aligned on a lane boundary when calculating
-	 * the expected data rate. This is done by extending HFP in case of
-	 * misalignment.
-	 */
-	adj_dsi_htotal = dsi_htotal;
-	if (dsi_htotal % lanes)
-		adj_dsi_htotal += lanes - (dsi_htotal % lanes);
+		dsi_cfg->hsa = 0;
+	}
 
-	dpi_hz = (mode_valid_check ? mode->clock : mode->crtc_clock) * 1000;
-	dlane_bps = (unsigned long long)dpi_hz * adj_dsi_htotal;
+	dsi_cfg->hact = dpi_to_dsi_timing(dpi_hact, bpp, 0);
 
-	/* data rate in bytes/sec is not an integer, refuse the mode. */
-	dpi_htotal = mode_valid_check ? mode->htotal : mode->crtc_htotal;
-	if (do_div(dlane_bps, lanes * dpi_htotal))
-		return -EINVAL;
+	dsi_cfg->hfp = dpi_to_dsi_timing(dpi_hfp, bpp, DSI_HFP_FRAME_OVERHEAD);
 
-	/* data rate was in bytes/sec, convert to bits/sec. */
-	phy_cfg->hs_clk_rate = dlane_bps * 8;
+	dsi_cfg->htotal = dsi_cfg->hact + dsi_cfg->hfp + DSI_HFP_FRAME_OVERHEAD;
 
-	dsi_hfp_ext = adj_dsi_htotal - dsi_htotal;
-	dsi_cfg->hfp += dsi_hfp_ext;
-	dsi_cfg->htotal = dsi_htotal + dsi_hfp_ext;
+	if (sync_pulse) {
+		dsi_cfg->htotal += dsi_cfg->hbp + DSI_HBP_FRAME_PULSE_OVERHEAD;
+		dsi_cfg->htotal += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
+	} else {
+		dsi_cfg->htotal += dsi_cfg->hbp + DSI_HBP_FRAME_EVENT_OVERHEAD;
+	}
 
 	return 0;
 }
 
 static int cdns_dsi_check_conf(struct cdns_dsi *dsi,
-			       const struct drm_display_mode *mode,
-			       struct cdns_dsi_cfg *dsi_cfg,
-			       bool mode_valid_check)
+			       const struct videomode *vm,
+			       struct cdns_dsi_cfg *dsi_cfg)
 {
 	struct cdns_dsi_output *output = &dsi->output;
 	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);
+	ret = cdns_dsi_mode2cfg(dsi, vm, dsi_cfg);
 	if (ret)
 		return ret;
 
-	ret = phy_mipi_dphy_get_default_config(mode_clock * 1000,
+	ret = phy_mipi_dphy_get_default_config(vm->pixelclock,
 					       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)
-		return ret;
-
 	ret = phy_validate(dsi->dphy, PHY_MODE_MIPI_DPHY, 0, &output->phy_opts);
 	if (ret)
 		return ret;
 
-	dsi_hss_hsa_hse_hbp = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
-	if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
-		dsi_hss_hsa_hse_hbp += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
-
-	/*
-	 * Make sure DPI(HFP) > DSI(HSS+HSA+HSE+HBP) to guarantee that the FIFO
-	 * is empty before we start a receiving a new line on the DPI
-	 * interface.
-	 */
-	if ((u64)phy_cfg->hs_clk_rate *
-	    mode_to_dpi_hfp(mode, mode_valid_check) * nlanes <
-	    (u64)dsi_hss_hsa_hse_hbp *
-	    (mode_valid_check ? mode->clock : mode->crtc_clock) * 1000)
-		return -EINVAL;
-
 	return 0;
 }
 
@@ -644,8 +569,7 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge,
 	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
 	struct cdns_dsi *dsi = input_to_dsi(input);
 	struct cdns_dsi_output *output = &dsi->output;
-	struct cdns_dsi_cfg dsi_cfg;
-	int bpp, ret;
+	int bpp;
 
 	/*
 	 * VFP_DSI should be less than VFP_DPI and VFP_DSI should be at
@@ -663,20 +587,31 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge,
 	if ((mode->hdisplay * bpp) % 32)
 		return MODE_H_ILLEGAL;
 
-	ret = cdns_dsi_check_conf(dsi, mode, &dsi_cfg, true);
-	if (ret)
-		return MODE_BAD;
-
 	return MODE_OK;
 }
 
-static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
-					   struct drm_atomic_state *state)
+static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
+						struct drm_atomic_state *state)
 {
 	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
 	struct cdns_dsi *dsi = input_to_dsi(input);
 	u32 val;
 
+	/*
+	 * The cdns-dsi controller needs to be disabled after it's DPI source
+	 * has stopped streaming. If this is not followed, there is a brief
+	 * window before DPI source is disabled and after cdns-dsi controller
+	 * has been disabled where the DPI stream is still on, but the cdns-dsi
+	 * controller is not ready anymore to accept the incoming signals. This
+	 * is one of the reasons why a shift in pixel colors is observed on
+	 * displays that have cdns-dsi as one of the bridges.
+	 *
+	 * To mitigate this, disable this bridge from the bridge post_disable()
+	 * hook, instead of the bridge _disable() hook. The bridge post_disable()
+	 * hook gets called after the CRTC disable, where often many DPI sources
+	 * disable their streams.
+	 */
+
 	val = readl(dsi->regs + MCTL_MAIN_DATA_CTL);
 	val &= ~(IF_VID_SELECT_MASK | IF_VID_MODE | VID_EN | HOST_EOT_GEN |
 		 DISP_EOT_GEN);
@@ -688,15 +623,6 @@ static void cdns_dsi_bridge_atomic_disable(struct drm_bridge *bridge,
 	if (dsi->platform_ops && dsi->platform_ops->disable)
 		dsi->platform_ops->disable(dsi);
 
-	pm_runtime_put(dsi->base.dev);
-}
-
-static void cdns_dsi_bridge_atomic_post_disable(struct drm_bridge *bridge,
-						struct drm_atomic_state *state)
-{
-	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);
@@ -774,8 +700,8 @@ static void cdns_dsi_init_link(struct cdns_dsi *dsi)
 	dsi->link_initialized = true;
 }
 
-static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
-					  struct drm_atomic_state *state)
+static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
+					      struct drm_atomic_state *state)
 {
 	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
 	struct cdns_dsi *dsi = input_to_dsi(input);
@@ -792,6 +718,21 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 	u32 tmp, reg_wakeup, div, status;
 	int nlanes;
 
+	/*
+	 * The cdns-dsi controller needs to be enabled before it's DPI source
+	 * has begun streaming. If this is not followed, there is a brief window
+	 * after DPI source enable and before cdns-dsi controller enable where
+	 * the DPI stream is on, but the cdns-dsi controller is not ready to
+	 * accept the incoming signals. This is one of the reasons why a shift
+	 * in pixel colors is observed on displays that have cdns-dsi as one of
+	 * the bridges.
+	 *
+	 * To mitigate this, enable this bridge from the bridge pre_enable()
+	 * hook, instead of the bridge _enable() hook. The bridge pre_enable()
+	 * hook gets called before the CRTC enable, where often many DPI sources
+	 * enable their streams.
+	 */
+
 	if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0))
 		return;
 
@@ -811,8 +752,8 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 	mode = &crtc_state->adjusted_mode;
 	nlanes = output->dev->lanes;
 
-	cdns_dsi_hs_init(dsi);
 	cdns_dsi_init_link(dsi);
+	cdns_dsi_hs_init(dsi);
 
 	/*
 	 * Now that the DSI Link and DSI Phy are initialized,
@@ -861,7 +802,13 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 
 	tx_byte_period = DIV_ROUND_DOWN_ULL((u64)NSEC_PER_SEC * 8,
 					    phy_cfg->hs_clk_rate);
-	reg_wakeup = (phy_cfg->hs_prepare + phy_cfg->hs_zero) / tx_byte_period;
+
+	/*
+	 * Estimated time [in clock cycles] to perform LP->HS on D-PHY.
+	 * It is not clear how to calculate this, so for now,
+	 * set it to 1/10 of the total number of clocks in a line.
+	 */
+	reg_wakeup = dsi_cfg.htotal / nlanes / 10;
 	writel(REG_WAKEUP_TIME(reg_wakeup) | REG_LINE_DURATION(tmp),
 	       dsi->regs + VID_DPHY_TIME);
 
@@ -941,19 +888,6 @@ static void cdns_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
 	writel(tmp, dsi->regs + MCTL_MAIN_EN);
 }
 
-static void cdns_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
-					      struct drm_atomic_state *state)
-{
-	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
-	struct cdns_dsi *dsi = input_to_dsi(input);
-
-	if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0))
-		return;
-
-	cdns_dsi_init_link(dsi);
-	cdns_dsi_hs_init(dsi);
-}
-
 static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
 					       struct drm_bridge_state *bridge_state,
 					       struct drm_crtc_state *crtc_state,
@@ -981,6 +915,28 @@ static u32 *cdns_dsi_bridge_get_input_bus_fmts(struct drm_bridge *bridge,
 	return input_fmts;
 }
 
+static long cdns_dsi_round_pclk(struct cdns_dsi *dsi, unsigned long pclk)
+{
+	struct cdns_dsi_output *output = &dsi->output;
+	unsigned int nlanes = output->dev->lanes;
+	union phy_configure_opts phy_opts = { 0 };
+	u32 bitspp;
+	int ret;
+
+	bitspp = mipi_dsi_pixel_format_to_bpp(output->dev->format);
+
+	ret = phy_mipi_dphy_get_default_config(pclk, bitspp, nlanes,
+					       &phy_opts.mipi_dphy);
+	if (ret)
+		return ret;
+
+	ret = phy_validate(dsi->dphy, PHY_MODE_MIPI_DPHY, 0, &phy_opts);
+	if (ret)
+		return ret;
+
+	return div_u64((u64)phy_opts.mipi_dphy.hs_clk_rate * nlanes, bitspp);
+}
+
 static int cdns_dsi_bridge_atomic_check(struct drm_bridge *bridge,
 					struct drm_bridge_state *bridge_state,
 					struct drm_crtc_state *crtc_state,
@@ -989,10 +945,32 @@ static int cdns_dsi_bridge_atomic_check(struct drm_bridge *bridge,
 	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);
 	struct cdns_dsi *dsi = input_to_dsi(input);
 	struct cdns_dsi_bridge_state *dsi_state = to_cdns_dsi_bridge_state(bridge_state);
-	const struct drm_display_mode *mode = &crtc_state->mode;
+	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
 	struct cdns_dsi_cfg *dsi_cfg = &dsi_state->dsi_cfg;
+	struct videomode vm;
+	long pclk;
+
+	/* cdns-dsi requires negative syncs */
+	adjusted_mode->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
+	adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC;
+
+	/*
+	 * The DPHY PLL has quite a coarsely grained clock rate options. See
+	 * what hsclk rate we can achieve based on the pixel clock, convert it
+	 * back to pixel clock, set that to the adjusted_mode->clock. This is
+	 * all in hopes that the CRTC will be able to provide us the requested
+	 * clock, as otherwise the DPI and DSI clocks will be out of sync.
+	 */
 
-	return cdns_dsi_check_conf(dsi, mode, dsi_cfg, false);
+	pclk = cdns_dsi_round_pclk(dsi, adjusted_mode->clock * 1000);
+	if (pclk < 0)
+		return (int)pclk;
+
+	adjusted_mode->clock = pclk / 1000;
+
+	drm_display_mode_to_videomode(adjusted_mode, &vm);
+
+	return cdns_dsi_check_conf(dsi, &vm, dsi_cfg);
 }
 
 static struct drm_bridge_state *
@@ -1048,9 +1026,7 @@ cdns_dsi_bridge_atomic_reset(struct drm_bridge *bridge)
 static const struct drm_bridge_funcs cdns_dsi_bridge_funcs = {
 	.attach = cdns_dsi_bridge_attach,
 	.mode_valid = cdns_dsi_bridge_mode_valid,
-	.atomic_disable = cdns_dsi_bridge_atomic_disable,
 	.atomic_pre_enable = cdns_dsi_bridge_atomic_pre_enable,
-	.atomic_enable = cdns_dsi_bridge_atomic_enable,
 	.atomic_post_disable = cdns_dsi_bridge_atomic_post_disable,
 	.atomic_check = cdns_dsi_bridge_atomic_check,
 	.atomic_reset = cdns_dsi_bridge_atomic_reset,
@@ -1076,10 +1052,6 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host,
 	if (output->dev)
 		return -EBUSY;
 
-	/* We do not support burst mode yet. */
-	if (dev->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
-		return -ENOTSUPP;
-
 	/*
 	 * The host <-> device link might be described using an OF-graph
 	 * representation, in this case we extract the device of_node from
@@ -1289,9 +1261,10 @@ static int cdns_dsi_drm_probe(struct platform_device *pdev)
 	int ret, irq;
 	u32 val;
 
-	dsi = devm_kzalloc(&pdev->dev, sizeof(*dsi), GFP_KERNEL);
-	if (!dsi)
-		return -ENOMEM;
+	dsi = devm_drm_bridge_alloc(&pdev->dev, struct cdns_dsi, input.bridge,
+				    &cdns_dsi_bridge_funcs);
+	if (IS_ERR(dsi))
+		return PTR_ERR(dsi);
 
 	platform_set_drvdata(pdev, dsi);
 
@@ -1349,7 +1322,6 @@ static int cdns_dsi_drm_probe(struct platform_device *pdev)
 	 * CDNS_DPI_INPUT.
 	 */
 	input->id = CDNS_DPI_INPUT;
-	input->bridge.funcs = &cdns_dsi_bridge_funcs;
 	input->bridge.of_node = pdev->dev.of_node;
 
 	/* Mask all interrupts before registering the IRQ handler. */
@@ -1436,4 +1408,3 @@ MODULE_AUTHOR("Boris Brezillon <boris.brezillon@bootlin.com>");
 MODULE_DESCRIPTION("Cadence DSI driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:cdns-dsi");
-