drm/panel: Add Innolux EJ030NA 3.0" 320x480 panel

Add support for the Innolux/Chimei EJ030NA 3.0"
320x480 TFT panel.

This panel can be found in the LDKs, RS97 V2.1 and RG300 (non IPS)
handheld gaming consoles.

While being 320x480, it is actually a horizontal 4:3
panel with non-square pixels in delta arrangement.
Signed-off-by: Christophe Branchereau <cbranchereau@gmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625121045.81711-2-paul@crapouillou.net

drivers/gpu/drm/panel/Kconfig

@@ -134,6 +134,15 @@ config DRM_PANEL_ILITEK_ILI9881C
 	  Say Y if you want to enable support for panels based on the
 	  Ilitek ILI9881c controller.
 
+config DRM_PANEL_INNOLUX_EJ030NA
+        tristate "Innolux EJ030NA 320x480 LCD panel"
+        depends on OF && SPI
+        select REGMAP_SPI
+        help
+          Say Y here to enable support for the Innolux/Chimei EJ030NA
+          320x480 3.0" panel as found in the RS97 V2.1, RG300(non-ips)
+          and LDK handheld gaming consoles.
+
 config DRM_PANEL_INNOLUX_P079ZCA
 	tristate "Innolux P079ZCA panel"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) += panel-feixin-k101-im2ba02.o
 obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
+obj-$(CONFIG_DRM_PANEL_INNOLUX_EJ030NA) += panel-innolux-ej030na.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_KHADAS_TS050) += panel-khadas-ts050.o

drivers/gpu/drm/panel/panel-innolux-ej030na.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Innolux/Chimei EJ030NA TFT LCD panel driver
+ *
+ * Copyright (C) 2020, Paul Cercueil <paul@crapouillou.net>
+ * Copyright (C) 2020, Christophe Branchereau <cbranchereau@gmail.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+struct ej030na_info {
+	const struct drm_display_mode *display_modes;
+	unsigned int num_modes;
+	u16 width_mm, height_mm;
+	u32 bus_format, bus_flags;
+};
+
+struct ej030na {
+	struct drm_panel panel;
+	struct spi_device *spi;
+	struct regmap *map;
+
+	const struct ej030na_info *panel_info;
+
+	struct regulator *supply;
+	struct gpio_desc *reset_gpio;
+};
+
+static inline struct ej030na *to_ej030na(struct drm_panel *panel)
+{
+	return container_of(panel, struct ej030na, panel);
+}
+
+static const struct reg_sequence ej030na_init_sequence[] = {
+	{ 0x05, 0x1e },
+	{ 0x05, 0x5c },
+	{ 0x02, 0x14 },
+	{ 0x03, 0x40 },
+	{ 0x04, 0x07 },
+	{ 0x06, 0x12 },
+	{ 0x07, 0xd2 },
+	{ 0x0c, 0x06 },
+	{ 0x0d, 0x40 },
+	{ 0x0e, 0x40 },
+	{ 0x0f, 0x40 },
+	{ 0x10, 0x40 },
+	{ 0x11, 0x40 },
+	{ 0x2f, 0x40 },
+	{ 0x5a, 0x02 },
+
+	{ 0x30, 0x07 },
+	{ 0x31, 0x57 },
+	{ 0x32, 0x53 },
+	{ 0x33, 0x77 },
+	{ 0x34, 0xb8 },
+	{ 0x35, 0xbd },
+	{ 0x36, 0xb8 },
+	{ 0x37, 0xe7 },
+	{ 0x38, 0x04 },
+	{ 0x39, 0xff },
+
+	{ 0x40, 0x0b },
+	{ 0x41, 0xb8 },
+	{ 0x42, 0xab },
+	{ 0x43, 0xb9 },
+	{ 0x44, 0x6a },
+	{ 0x45, 0x56 },
+	{ 0x46, 0x61 },
+	{ 0x47, 0x08 },
+	{ 0x48, 0x0f },
+	{ 0x49, 0x0f },
+
+	{ 0x2b, 0x01 },
+};
+
+static int ej030na_prepare(struct drm_panel *panel)
+{
+	struct ej030na *priv = to_ej030na(panel);
+	struct device *dev = &priv->spi->dev;
+	int err;
+
+	err = regulator_enable(priv->supply);
+	if (err) {
+		dev_err(dev, "Failed to enable power supply: %d\n", err);
+		return err;
+	}
+
+	/* Reset the chip */
+	gpiod_set_value_cansleep(priv->reset_gpio, 1);
+	usleep_range(50, 150);
+	gpiod_set_value_cansleep(priv->reset_gpio, 0);
+	usleep_range(50, 150);
+
+	err = regmap_multi_reg_write(priv->map, ej030na_init_sequence,
+				     ARRAY_SIZE(ej030na_init_sequence));
+	if (err) {
+		dev_err(dev, "Failed to init registers: %d\n", err);
+		goto err_disable_regulator;
+	}
+
+	msleep(120);
+
+	return 0;
+
+err_disable_regulator:
+	regulator_disable(priv->supply);
+	return err;
+}
+
+static int ej030na_unprepare(struct drm_panel *panel)
+{
+	struct ej030na *priv = to_ej030na(panel);
+
+	gpiod_set_value_cansleep(priv->reset_gpio, 1);
+	regulator_disable(priv->supply);
+
+	return 0;
+}
+
+static int ej030na_get_modes(struct drm_panel *panel,
+			     struct drm_connector *connector)
+{
+	struct ej030na *priv = to_ej030na(panel);
+	const struct ej030na_info *panel_info = priv->panel_info;
+	struct drm_display_mode *mode;
+	unsigned int i;
+
+	for (i = 0; i < panel_info->num_modes; i++) {
+		mode = drm_mode_duplicate(connector->dev,
+					  &panel_info->display_modes[i]);
+		if (!mode)
+			return -ENOMEM;
+
+		drm_mode_set_name(mode);
+
+		mode->type = DRM_MODE_TYPE_DRIVER;
+		if (panel_info->num_modes == 1)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+		drm_mode_probed_add(connector, mode);
+	}
+
+	connector->display_info.bpc = 8;
+	connector->display_info.width_mm = panel_info->width_mm;
+	connector->display_info.height_mm = panel_info->height_mm;
+
+	drm_display_info_set_bus_formats(&connector->display_info,
+					 &panel_info->bus_format, 1);
+	connector->display_info.bus_flags = panel_info->bus_flags;
+
+	return panel_info->num_modes;
+}
+
+static const struct drm_panel_funcs ej030na_funcs = {
+	.prepare	= ej030na_prepare,
+	.unprepare	= ej030na_unprepare,
+	.get_modes	= ej030na_get_modes,
+};
+
+static const struct regmap_config ej030na_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x5a,
+};
+
+static int ej030na_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct ej030na *priv;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->spi = spi;
+	spi_set_drvdata(spi, priv);
+
+	priv->map = devm_regmap_init_spi(spi, &ej030na_regmap_config);
+	if (IS_ERR(priv->map)) {
+		dev_err(dev, "Unable to init regmap\n");
+		return PTR_ERR(priv->map);
+	}
+
+	priv->panel_info = of_device_get_match_data(dev);
+	if (!priv->panel_info)
+		return -EINVAL;
+
+	priv->supply = devm_regulator_get(dev, "power");
+	if (IS_ERR(priv->supply)) {
+		dev_err(dev, "Failed to get power supply\n");
+		return PTR_ERR(priv->supply);
+	}
+
+	priv->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->reset_gpio)) {
+		dev_err(dev, "Failed to get reset GPIO\n");
+		return PTR_ERR(priv->reset_gpio);
+	}
+
+	drm_panel_init(&priv->panel, dev, &ej030na_funcs,
+		       DRM_MODE_CONNECTOR_DPI);
+
+	err = drm_panel_of_backlight(&priv->panel);
+	if (err)
+		return err;
+
+	drm_panel_add(&priv->panel);
+
+	return 0;
+}
+
+static int ej030na_remove(struct spi_device *spi)
+{
+	struct ej030na *priv = spi_get_drvdata(spi);
+
+	drm_panel_remove(&priv->panel);
+	drm_panel_disable(&priv->panel);
+	drm_panel_unprepare(&priv->panel);
+
+	return 0;
+}
+
+static const struct drm_display_mode ej030na_modes[] = {
+	{ /* 60 Hz */
+		.clock = 14400,
+		.hdisplay = 320,
+		.hsync_start = 320 + 10,
+		.hsync_end = 320 + 10 + 37,
+		.htotal = 320 + 10 + 37 + 33,
+		.vdisplay = 480,
+		.vsync_start = 480 + 102,
+		.vsync_end = 480 + 102 + 9 + 9,
+		.vtotal = 480 + 102 + 9 + 9,
+		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	},
+	{ /* 50 Hz */
+		.clock = 12000,
+		.hdisplay = 320,
+		.hsync_start = 320 + 10,
+		.hsync_end = 320 + 10 + 37,
+		.htotal = 320 + 10 + 37 + 33,
+		.vdisplay = 480,
+		.vsync_start = 480 + 102,
+		.vsync_end = 480 + 102 + 9,
+		.vtotal = 480 + 102 + 9 + 9,
+		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	},
+};
+
+static const struct ej030na_info ej030na_info = {
+	.display_modes = ej030na_modes,
+	.num_modes = ARRAY_SIZE(ej030na_modes),
+	.width_mm = 70,
+	.height_mm = 51,
+	.bus_format = MEDIA_BUS_FMT_RGB888_3X8_DELTA,
+	.bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE | DRM_BUS_FLAG_DE_LOW,
+};
+
+static const struct of_device_id ej030na_of_match[] = {
+	{ .compatible = "innolux,ej030na", .data = &ej030na_info },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ej030na_of_match);
+
+static struct spi_driver ej030na_driver = {
+	.driver = {
+		.name = "panel-innolux-ej030na",
+		.of_match_table = ej030na_of_match,
+	},
+	.probe = ej030na_probe,
+	.remove = ej030na_remove,
+};
+module_spi_driver(ej030na_driver);
+
+MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
+MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
+MODULE_LICENSE("GPL v2");