drm/panel: Add Samsung s6e88a0-ams452ef01 panel driver

Add driver for Samsung AMS452EF01 AMOLED panel, which makes
use of their S6E88A0 controller.

Signed-off-by: Michael Srba <[e-mail]>
Signed-off-by: Sam Ravnborg <[e-mail]>
[fixed checkpatch warnings, added changelog]
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/panel/Kconfig

···
 	  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

drivers/gpu/drm/panel/Makefile

···
 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

drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams452ef01.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019, Michael Srba
+
+#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>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.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
+	// set default Amoled Off Ratio
+	dsi_dcs_write_seq(dsi, 0xb2, 0x40, 0x0a, 0x17, 0x00, 0x0a);
+	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 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_connector *connector)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, &s6e88a0_ams452ef01_mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	connector->display_info.width_mm = mode->width_mm;
+	connector->display_info.height_mm = mode->height_mm;
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_panel_funcs s6e88a0_ams452ef01_panel_funcs = {
+	.unprepare = s6e88a0_ams452ef01_unprepare,
+	.prepare = s6e88a0_ams452ef01_prepare,
+	.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" },
+	{ /* sentinel */ },
+};
+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 <[e-mail]>");
+MODULE_DESCRIPTION("MIPI-DSI based Panel Driver for AMS452EF01 AMOLED LCD with a S6E88A0 controller");
+MODULE_LICENSE("GPL v2");