[PATCH 2/2] drm/panel: Add a driver for Samsung s6e88a0-ams452ef01 panel

michael.srba at seznam.cz michael.srba at seznam.cz
Sun Jan 26 18:39:11 UTC 2020


From: Michael Srba <Michael.Srba at seznam.cz>

Add a driver for Samsung AMS452EF01 AMOLED panel, which makes use of their
S6E88A0 controller. Basic functionality is supported, with the only notable 
feature missing being backlight control. Backlight control on these panels is 
complex and hard to make look nice, mainly courtesy of magic look up tables. If
it is to be added, it should be with a separate patch.

Signed-off-by: Michael Srba <Michael.Srba at seznam.cz>
---
 drivers/gpu/drm/panel/Kconfig                 |   6 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../panel/panel-samsung-s6e88a0-ams452ef01.c  | 299 ++++++++++++++++++
 3 files changed, 306 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams452ef01.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index ae44ac2ec106..0c7d61f32b0e 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -275,6 +275,12 @@ config DRM_PANEL_SAMSUNG_S6E63M0
 	  Say Y here if you want to enable support for Samsung S6E63M0
 	  AMOLED LCD panel.

+config DRM_PANEL_SAMSUNG_S6E88A0_AMS452EF01
+	tristate "Samsung AMS452EF01 panel with S6E88A0 DSI video mode controller"
+	depends on OF
+	select DRM_MIPI_DSI
+	select VIDEOMODE_HELPERS
+
 config DRM_PANEL_SAMSUNG_S6E8AA0
 	tristate "Samsung S6E8AA0 DSI video mode panel"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 7c4d3c581fd4..5b622fbe4014 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6D16D0) += panel-samsung-s6d16d0.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E3HA2) += panel-samsung-s6e3ha2.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63J0X03) += panel-samsung-s6e63j0x03.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63M0) += panel-samsung-s6e63m0.o
+obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS452EF01) += panel-samsung-s6e88a0-ams452ef01.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
 obj-$(CONFIG_DRM_PANEL_SEIKO_43WVF1G) += panel-seiko-43wvf1g.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams452ef01.c b/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams452ef01.c
new file mode 100644
index 000000000000..10eb1ffc1bba
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams452ef01.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019, Michael Srba
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <video/mipi_display.h>
+
+struct s6e88a0_ams452ef01 {
+	struct drm_panel panel;
+	struct mipi_dsi_device *dsi;
+	struct regulator_bulk_data supplies[2];
+	struct gpio_desc *reset_gpio;
+
+	bool prepared;
+};
+
+static inline struct s6e88a0_ams452ef01 *to_s6e88a0_ams452ef01(struct drm_panel *panel)
+{
+	return container_of(panel, struct s6e88a0_ams452ef01, panel);
+}
+
+#define dsi_dcs_write_seq(dsi, seq...) do {				\
+		static const u8 d[] = { seq };				\
+		int ret;						\
+		ret = mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d));	\
+		if (ret < 0)						\
+			return ret;					\
+	} while (0)
+
+static void s6e88a0_ams452ef01_reset(struct s6e88a0_ams452ef01 *ctx)
+{
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(5000, 6000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(1000, 2000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(10000, 11000);
+}
+
+static int s6e88a0_ams452ef01_on(struct s6e88a0_ams452ef01 *ctx)
+{
+	struct mipi_dsi_device *dsi = ctx->dsi;
+	struct device *dev = &dsi->dev;
+	int ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	dsi_dcs_write_seq(dsi, 0xf0, 0x5a, 0x5a); // enable LEVEL2 commands
+	dsi_dcs_write_seq(dsi, 0xcc, 0x4c); // set Pixel Clock Divider polarity
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		dev_err(dev, "Failed to exit sleep mode: %d\n", ret);
+		return ret;
+	}
+	msleep(120);
+
+	// set default brightness/gama
+	dsi_dcs_write_seq(dsi, 0xca,
+			  0x01, 0x00, 0x01, 0x00, 0x01, 0x00,	// V255 RR,GG,BB
+			  0x80, 0x80, 0x80,			// V203 R,G,B
+			  0x80, 0x80, 0x80,			// V151 R,G,B
+			  0x80, 0x80, 0x80,			// V87  R,G,B
+			  0x80, 0x80, 0x80,			// V51  R,G,B
+			  0x80, 0x80, 0x80,			// V35  R,G,B
+			  0x80, 0x80, 0x80,			// V23  R,G,B
+			  0x80, 0x80, 0x80,			// V11  R,G,B
+			  0x6b, 0x68, 0x71,			// V3   R,G,B
+			  0x00, 0x00, 0x00);			// V1   R,G,B
+	dsi_dcs_write_seq(dsi, 0xb2, 0x40, 0x0a, 0x17, 0x00, 0x0a); // set default Amoled Off Ratio
+	dsi_dcs_write_seq(dsi, 0xb6, 0x2c, 0x0b); // set default elvss voltage
+	dsi_dcs_write_seq(dsi, MIPI_DCS_WRITE_POWER_SAVE, 0x00);
+	dsi_dcs_write_seq(dsi, 0xf7, 0x03); // gamma/aor update
+	dsi_dcs_write_seq(dsi, 0xf0, 0xa5, 0xa5); // disable LEVEL2 commands
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret < 0) {
+		dev_err(dev, "Failed to set display on: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int s6e88a0_ams452ef01_off(struct s6e88a0_ams452ef01 *ctx)
+{
+	struct mipi_dsi_device *dsi = ctx->dsi;
+	struct device *dev = &dsi->dev;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0) {
+		dev_err(dev, "Failed to set display off: %d\n", ret);
+		return ret;
+	}
+	msleep(35);
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0) {
+		dev_err(dev, "Failed to enter sleep mode: %d\n", ret);
+		return ret;
+	}
+	msleep(120);
+
+	return 0;
+}
+
+static int s6e88a0_ams452ef01_prepare(struct drm_panel *panel)
+{
+	struct s6e88a0_ams452ef01 *ctx = to_s6e88a0_ams452ef01(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	if (ctx->prepared)
+		return 0;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	if (ret < 0) {
+		dev_err(dev, "Failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+
+	s6e88a0_ams452ef01_reset(ctx);
+
+	ret = s6e88a0_ams452ef01_on(ctx);
+	if (ret < 0) {
+		dev_err(dev, "Failed to initialize panel: %d\n", ret);
+		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+		regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+		return ret;
+	}
+
+	ctx->prepared = true;
+	return 0;
+}
+
+static int s6e88a0_ams452ef01_unprepare(struct drm_panel *panel)
+{
+	struct s6e88a0_ams452ef01 *ctx = to_s6e88a0_ams452ef01(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	if (!ctx->prepared)
+		return 0;
+
+	ret = s6e88a0_ams452ef01_off(ctx);
+	if (ret < 0)
+		dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+
+	ctx->prepared = false;
+	return 0;
+}
+
+static int s6e88a0_ams452ef01_enable(struct drm_panel *panel)
+{
+	return 0;
+}
+
+static int s6e88a0_ams452ef01_disable(struct drm_panel *panel)
+{
+	return 0;
+}
+
+static const struct drm_display_mode s6e88a0_ams452ef01_mode = {
+	.clock = (540 + 88 + 4 + 20) * (960 + 14 + 2 + 8) * 60 / 1000,
+	.hdisplay = 540,
+	.hsync_start = 540 + 88,
+	.hsync_end = 540 + 88 + 4,
+	.htotal = 540 + 88 + 4 + 20,
+	.vdisplay = 960,
+	.vsync_start = 960 + 14,
+	.vsync_end = 960 + 14 + 2,
+	.vtotal = 960 + 14 + 2 + 8,
+	.vrefresh = 60,
+	.width_mm = 56,
+	.height_mm = 100,
+};
+
+static int s6e88a0_ams452ef01_get_modes(struct drm_panel *panel)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &s6e88a0_ams452ef01_mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	panel->connector->display_info.width_mm = mode->width_mm;
+	panel->connector->display_info.height_mm = mode->height_mm;
+	drm_mode_probed_add(panel->connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs s6e88a0_ams452ef01_panel_funcs = {
+	.disable = s6e88a0_ams452ef01_disable,
+	.unprepare = s6e88a0_ams452ef01_unprepare,
+	.prepare = s6e88a0_ams452ef01_prepare,
+	.enable = s6e88a0_ams452ef01_enable,
+	.get_modes = s6e88a0_ams452ef01_get_modes,
+};
+
+static int s6e88a0_ams452ef01_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct s6e88a0_ams452ef01 *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->supplies[0].supply = "vdd3";
+	ctx->supplies[1].supply = "vci";
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
+				      ctx->supplies);
+	if (ret < 0) {
+		dev_err(dev, "Failed to get regulators: %d\n", ret);
+		return ret;
+	}
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		ret = PTR_ERR(ctx->reset_gpio);
+		dev_err(dev, "Failed to get reset-gpios: %d\n", ret);
+		return ret;
+	}
+
+	ctx->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	dsi->lanes = 2;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST;
+
+	drm_panel_init(&ctx->panel, dev, &s6e88a0_ams452ef01_panel_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+
+	ret = drm_panel_add(&ctx->panel);
+	if (ret < 0) {
+		dev_err(dev, "Failed to add panel: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		dev_err(dev, "Failed to attach to DSI host: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int s6e88a0_ams452ef01_remove(struct mipi_dsi_device *dsi)
+{
+	struct s6e88a0_ams452ef01 *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
+
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct of_device_id s6e88a0_ams452ef01_of_match[] = {
+	{ .compatible = "samsung,s6e88a0-ams452ef01" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, s6e88a0_ams452ef01_of_match);
+
+static struct mipi_dsi_driver s6e88a0_ams452ef01_driver = {
+	.probe = s6e88a0_ams452ef01_probe,
+	.remove = s6e88a0_ams452ef01_remove,
+	.driver = {
+		.name = "panel-s6e88a0-ams452ef01",
+		.of_match_table = s6e88a0_ams452ef01_of_match,
+	},
+};
+module_mipi_dsi_driver(s6e88a0_ams452ef01_driver);
+
+MODULE_AUTHOR("Michael Srba <Michael.Srba at seznam.cz>");
+MODULE_DESCRIPTION("MIPI-DSI based Panel Driver for AMS452EF01 AMOLED LCD with a S6E88A0 controller");
+MODULE_LICENSE("GPL v2");
-- 
2.24.0



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