[PATCH 2/2] drm/panel: add Ilitek ILI7836A panel driver

[Aaron Kling via B4 Relay <devnull+webgeek1234.gmail.com@kernel.org>]

From: Aaron Kling <webgeek1234@gmail.com>

This is a DDIC which can be used in various panels. The first
supported panel is the one used in the Retroid Pocket Nova.

Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
---
 drivers/gpu/drm/panel/Kconfig                 |  11 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 drivers/gpu/drm/panel/panel-ilitek-ili7836a.c | 297 ++++++++++++++++++++++++++
 3 files changed, 309 insertions(+)

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index cbdf7b8f7f7af..792d6b92798d9 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -298,6 +298,17 @@ config DRM_PANEL_ILITEK_ILI7807S
 
 	  If M is selected the module will be called panel-ilitek-ili7807s.
 
+config DRM_PANEL_ILITEK_ILI7836A
+	tristate "Ilitek ILI7836A-based panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Ilitek ILI7836A DDIC.
+
+	  If M is selected the module will be called panel-ilitek-ili7836a.
+
 config DRM_PANEL_ILITEK_IL9322
 	tristate "Ilitek ILI9322 320x240 QVGA panels"
 	depends on OF && SPI
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 3b523cf378330..be96f4e8112da 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_DRM_PANEL_HIMAX_HX83121A) += panel-himax-hx83121a.o
 obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
 obj-$(CONFIG_DRM_PANEL_HYDIS_HV101HD1) += panel-hydis-hv101hd1.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI7807S) += panel-ilitek-ili7807s.o
+obj-$(CONFIG_DRM_PANEL_ILITEK_ILI7836A) += panel-ilitek-ili7836a.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9488) += panel-ilitek-ili9488.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili7836a.c b/drivers/gpu/drm/panel/panel-ilitek-ili7836a.c
new file mode 100644
index 0000000000000..f6331129dadf2
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili7836a.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+
+#include <video/mipi_display.h>
+
+static const struct regulator_bulk_data ili7836a_supplies[] = {
+	{ .supply = "vddio", },
+	{ .supply = "avdd", },
+};
+
+struct ili7836a_panel {
+	struct drm_panel panel;
+	struct drm_connector *connector;
+	struct mipi_dsi_device *dsi;
+	struct regulator_bulk_data *supplies;
+	struct gpio_desc *reset_gpio;
+	struct ili7836a_desc *desc;
+	enum drm_panel_orientation orientation;
+};
+
+struct ili7836a_desc {
+	unsigned int width_mm;
+	unsigned int height_mm;
+	unsigned int bpc;
+
+	const struct drm_display_mode *modes;
+	unsigned int num_modes;
+};
+
+static inline struct ili7836a_panel *to_ili7836a_panel(struct drm_panel *panel)
+{
+	return container_of(panel, struct ili7836a_panel, panel);
+}
+
+static void ili7836a_reset(struct ili7836a_panel *ctx)
+{
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	msleep(20);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	msleep(20);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	msleep(20);
+}
+
+static int ili7836a_on(struct ili7836a_panel *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	ctx->dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x08);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xc8, 0x62);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x21);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xa4, 0x38);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x23);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x85, 0x15);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x60, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x6d, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x35);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x53, 0x20);
+
+	mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 120);
+
+	mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 20);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x22);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xe1, 0x01);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xff, 0x5a, 0xa5, 0x00);
+
+	return dsi_ctx.accum_err;
+}
+
+static int ili7836a_disable(struct drm_panel *panel)
+{
+	struct ili7836a_panel *ctx = to_ili7836a_panel(panel);
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	ctx->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 20);
+	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 120);
+
+	return dsi_ctx.accum_err;
+}
+
+static int ili7836a_prepare(struct drm_panel *panel)
+{
+	struct ili7836a_panel *ctx = to_ili7836a_panel(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ili7836a_supplies), ctx->supplies);
+	if (ret < 0) {
+		dev_err(dev, "Failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+
+	ili7836a_reset(ctx);
+
+	ret = ili7836a_on(ctx);
+	if (ret < 0) {
+		dev_err(dev, "Failed to initialize panel: %d\n", ret);
+		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+		regulator_bulk_disable(ARRAY_SIZE(ili7836a_supplies), ctx->supplies);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int ili7836a_unprepare(struct drm_panel *panel)
+{
+	struct ili7836a_panel *ctx = to_ili7836a_panel(panel);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	regulator_bulk_disable(ARRAY_SIZE(ili7836a_supplies), ctx->supplies);
+
+	return 0;
+}
+
+static const struct drm_display_mode nova_modes[] = {
+	{
+		/* 120Hz */
+		.clock = (1280 + 12 + 2 + 8) * (960 + 12 + 2 + 24) * 120 / 1000,
+		.hdisplay = 1280,
+		.hsync_start = 1280 + 12,
+		.hsync_end = 1280 + 12 + 2,
+		.htotal = 1280 + 12 + 2 + 8,
+		.vdisplay = 960,
+		.vsync_start = 960 + 12,
+		.vsync_end = 960 + 12 + 2,
+		.vtotal = 960 + 12 + 2 + 24,
+	}
+};
+
+static struct ili7836a_desc nova_desc = {
+	.modes = nova_modes,
+	.num_modes = ARRAY_SIZE(nova_modes),
+	.width_mm = 91,
+	.height_mm = 68,
+	.bpc = 8,
+};
+
+static int ili7836a_get_modes(struct drm_panel *panel,
+					struct drm_connector *connector)
+{
+	struct ili7836a_panel *ctx = to_ili7836a_panel(panel);
+
+	return drm_connector_helper_get_modes_fixed(connector, ctx->desc->modes);
+}
+
+static enum drm_panel_orientation ili7836a_get_orientation(struct drm_panel *panel)
+{
+	struct ili7836a_panel *ctx = to_ili7836a_panel(panel);
+
+	return ctx->orientation;
+}
+
+static const struct drm_panel_funcs ili7836a_panel_funcs = {
+	.prepare = ili7836a_prepare,
+	.unprepare = ili7836a_unprepare,
+	.disable = ili7836a_disable,
+	.get_modes = ili7836a_get_modes,
+	.get_orientation = ili7836a_get_orientation,
+};
+
+static int ili7836a_bl_update_status(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	u16 brightness = backlight_get_brightness(bl);
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return 0;
+}
+
+static const struct backlight_ops ili7836a_bl_ops = {
+	.update_status = ili7836a_bl_update_status,
+};
+
+static struct backlight_device *
+ili7836a_create_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 3445,
+		.max_brightness = 3445,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &ili7836a_bl_ops, &props);
+}
+
+static int ili7836a_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct ili7836a_panel *ctx;
+	int ret;
+
+	ctx = devm_drm_panel_alloc(dev, __typeof(*ctx), panel,
+				   &ili7836a_panel_funcs,
+				   DRM_MODE_CONNECTOR_DSI);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	ctx->desc = (struct ili7836a_desc *)of_device_get_match_data(dev);
+	if (!ctx->desc)
+		return -ENODEV;
+
+	ret = devm_regulator_bulk_get_const(dev,
+					    ARRAY_SIZE(ili7836a_supplies),
+					    ili7836a_supplies,
+					    &ctx->supplies);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to get regulators\n");
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ctx->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+				     "Failed to get reset-gpios\n");
+
+	ret = drm_of_get_panel_orientation(dev->of_node, &ctx->orientation);
+	if (ret < 0) {
+		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, ret);
+		return ret;
+	}
+
+	ctx->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_HSE |
+			  MIPI_DSI_MODE_NO_EOT_PACKET | MIPI_DSI_CLOCK_NON_CONTINUOUS;
+
+	ctx->panel.prepare_prev_first = true;
+
+	ctx->panel.backlight = ili7836a_create_backlight(dsi);
+	if (IS_ERR(ctx->panel.backlight))
+		return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+				     "Failed to create backlight\n");
+
+	ret = devm_drm_panel_add(dev, &ctx->panel);
+	if (ret)
+		return ret;
+
+	return devm_mipi_dsi_attach(dev, dsi);
+}
+
+static const struct of_device_id ili7836a_of_match[] = {
+	{ .compatible = "retroidpocket,nova-panel", .data = &nova_desc },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ili7836a_of_match);
+
+static struct mipi_dsi_driver ili7836a_driver = {
+	.probe = ili7836a_probe,
+	.driver = {
+		.name = "panel-ili7836a-amoled",
+		.of_match_table = ili7836a_of_match,
+	},
+};
+module_mipi_dsi_driver(ili7836a_driver);
+
+MODULE_DESCRIPTION("DRM driver for ILI7836A DSI panels");
+MODULE_LICENSE("GPL");

-- 
2.54.0