[PATCH] drm: bridge: samsung-dsim: Add i.MX8M Plus support

Marek Vasut marex at denx.de
Sat Oct 15 15:07:53 PDT 2022


Add extras to support i.MX8M Plus. The main change is the removal of
HS/VS/DE signal inversion in the LCDIFv3-DSIM glue logic, otherwise
the implementation of this IP in i.MX8M Plus is very much compatible
with the i.MX8M Mini/Nano one.

Signed-off-by: Marek Vasut <marex at denx.de>
---
Cc: Adam Ford <aford173 at gmail.com>
Cc: Andrzej Hajda <andrzej.hajda at intel.com>
Cc: Frieder Schrempf <frieder.schrempf at kontron.de>
Cc: Inki Dae <inki.dae at samsung.com>
Cc: Jagan Teki <jagan at amarulasolutions.com>
Cc: Kyungmin Park <kyungmin.park at samsung.com>
Cc: Laurent Pinchart <Laurent.pinchart at ideasonboard.com>
Cc: Marek Szyprowski <m.szyprowski at samsung.com>
Cc: Matteo Lisi <matteo.lisi at engicam.com>
Cc: Michael Nazzareno Trimarchi <michael at amarulasolutions.com>
Cc: NXP Linux Team <linux-imx at nxp.com>
Cc: Robert Foss <robert.foss at linaro.org>
Cc: Seung-Woo Kim <sw0312.kim at samsung.com>
Cc: Tim Harvey <tharvey at gateworks.com>
Cc: Tommaso Merciai <tommaso.merciai at amarulasolutions.com>
Cc: linux-amarula <linux-amarula at amarulasolutions.com>
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-samsung-soc at vger.kernel.org
To: dri-devel at lists.freedesktop.org
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 55 +++++++++++++++++++++------
 include/drm/bridge/samsung-dsim.h     |  1 +
 2 files changed, 44 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
index 012d8b6463ad6..cf40fd8813ff2 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -465,6 +465,7 @@ samsung_dsim_types[SAMSUNG_DSIM_TYPE_COUNT] = {
 	[SAMSUNG_DSIM_TYPE_EXYNOS5422] = &exynos5422_dsi_driver_data,
 	[SAMSUNG_DSIM_TYPE_EXYNOS5433] = &exynos5433_dsi_driver_data,
 	[SAMSUNG_DSIM_TYPE_IMX8MM] = &imx8mm_dsi_driver_data,
+	[SAMSUNG_DSIM_TYPE_IMX8MP] = &imx8mm_dsi_driver_data,
 };
 
 static inline struct samsung_dsim *host_to_dsi(struct mipi_dsi_host *h)
@@ -1404,18 +1405,26 @@ static int samsung_dsim_atomic_check(struct drm_bridge *bridge,
 	struct samsung_dsim *dsi = bridge_to_dsi(bridge);
 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
 
+	/*
+	 * The i.MX8M Mini/Nano glue logic between LCDIF and DSIM
+	 * inverts HS/VS/DE sync signals polarity, therefore, while
+	 * i.MX 8M Mini Applications Processor Reference Manual Rev. 3, 11/2020
+	 * 13.6.3.5.2 RGB interface
+	 * i.MX 8M Nano Applications Processor Reference Manual Rev. 2, 07/2022
+	 * 13.6.2.7.2 RGB interface
+	 * both claim "Vsync, Hsync, and VDEN are active high signals.", the
+	 * LCDIF must generate inverted HS/VS/DE signals, i.e. active LOW.
+	 *
+	 * The i.MX8M Plus glue logic between LCDIFv3 and DSIM does not
+	 * implement the same behavior, therefore LCDIFv3 must generate
+	 * HS/VS/DE signals active HIGH.
+	 */
 	if (dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MM) {
-		/**
-		 * FIXME:
-		 * At least LCDIF + DSIM needs active low sync,
-		 * but i.MX 8M Mini Applications Processor Reference Manual,
-		 * Rev. 3, 11/2020 says
-		 *
-		 * 13.6.3.5.2 RGB interface
-		 * Vsync, Hsync, and VDEN are active high signals.
-		 */
 		adjusted_mode->flags |= (DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
 		adjusted_mode->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
+	} else if (dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MP) {
+		adjusted_mode->flags &= ~(DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC);
+		adjusted_mode->flags |= (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);
 	}
 
 	return 0;
@@ -1448,7 +1457,8 @@ static int samsung_dsim_attach(struct drm_bridge *bridge,
 	 * Passing NULL to the previous bridge makes Exynos DSI drivers
 	 * work which is exactly done before.
 	 */
-	if (!(dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MM))
+	if (dsi->plat_data->hw_type != SAMSUNG_DSIM_TYPE_IMX8MM &&
+	    dsi->plat_data->hw_type != SAMSUNG_DSIM_TYPE_IMX8MP)
 		previous = NULL;
 
 	return drm_bridge_attach(bridge->encoder, dsi->out_bridge, previous,
@@ -1649,7 +1659,11 @@ static const struct samsung_dsim_host_ops samsung_dsim_generic_host_ops = {
 	.unregister_host = samsung_dsim_unregister_host,
 };
 
-static const struct drm_bridge_timings samsung_dsim_bridge_timings = {
+static const struct drm_bridge_timings samsung_dsim_bridge_timings_de_high = {
+	.input_bus_flags = DRM_BUS_FLAG_DE_HIGH,
+};
+
+static const struct drm_bridge_timings samsung_dsim_bridge_timings_de_low = {
 	.input_bus_flags = DRM_BUS_FLAG_DE_LOW,
 };
 
@@ -1733,9 +1747,17 @@ int samsung_dsim_probe(struct platform_device *pdev)
 
 	dsi->bridge.funcs = &samsung_dsim_bridge_funcs;
 	dsi->bridge.of_node = dev->of_node;
-	dsi->bridge.timings = &samsung_dsim_bridge_timings;
 	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
 
+	/*
+	 * The i.MX8M Mini/Nano LCDIF-DSIM glue logic inverts DE signal
+	 * polarity, see comment in samsung_dsim_atomic_check().
+	 */
+	if (dsi->plat_data->hw_type == SAMSUNG_DSIM_TYPE_IMX8MM)
+		dsi->bridge.timings = &samsung_dsim_bridge_timings_de_low;
+	else
+		dsi->bridge.timings = &samsung_dsim_bridge_timings_de_high;
+
 	if (dsi->plat_data->host_ops && dsi->plat_data->host_ops->register_host)
 		ret = dsi->plat_data->host_ops->register_host(dsi);
 
@@ -1841,11 +1863,20 @@ static const struct samsung_dsim_plat_data samsung_dsim_imx8mm_pdata = {
 	.host_ops = &samsung_dsim_generic_host_ops,
 };
 
+static const struct samsung_dsim_plat_data samsung_dsim_imx8mp_pdata = {
+	.hw_type = SAMSUNG_DSIM_TYPE_IMX8MP,
+	.host_ops = &samsung_dsim_generic_host_ops,
+};
+
 static const struct of_device_id samsung_dsim_of_match[] = {
 	{
 		.compatible = "fsl,imx8mm-mipi-dsim",
 		.data = &samsung_dsim_imx8mm_pdata,
 	},
+	{
+		.compatible = "fsl,imx8mp-mipi-dsim",
+		.data = &samsung_dsim_imx8mp_pdata,
+	},
 	{ /* sentinel. */ }
 };
 MODULE_DEVICE_TABLE(of, samsung_dsim_of_match);
diff --git a/include/drm/bridge/samsung-dsim.h b/include/drm/bridge/samsung-dsim.h
index df3d030daec6a..3789f9dbb238b 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -28,6 +28,7 @@ enum samsung_dsim_type {
 	SAMSUNG_DSIM_TYPE_EXYNOS5422,
 	SAMSUNG_DSIM_TYPE_EXYNOS5433,
 	SAMSUNG_DSIM_TYPE_IMX8MM,
+	SAMSUNG_DSIM_TYPE_IMX8MP,
 	SAMSUNG_DSIM_TYPE_COUNT,
 };
 
-- 
2.35.1




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