drm/panel: add the orisetech ota5601a

Add the orisetech ota5601a ic driver

For now it only supports the focaltech gpt3 3" 640x480 ips panel
found in the ylm rg300x handheld.
Signed-off-by: Christophe Branchereau <cbranchereau@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219195233.375637-2-cbranchereau@gmail.com

drivers/gpu/drm/panel/Kconfig

@@ -400,6 +400,15 @@ config DRM_PANEL_OLIMEX_LCD_OLINUXINO
 	  Say Y here if you want to enable support for Olimex Ltd.
 	  LCD-OLinuXino panel.
 
+config DRM_PANEL_ORISETECH_OTA5601A
+        tristate "Orise Technology ota5601a RGB/SPI panel"
+        depends on SPI
+        depends on BACKLIGHT_CLASS_DEVICE
+        select REGMAP_SPI
+        help
+          Say Y here if you want to enable support for the panels built
+          around the Orise Technology OTA9601A display controller.
+
 config DRM_PANEL_ORISETECH_OTM8009A
 	tristate "Orise Technology otm8009a 480x800 dsi 2dl panel"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -37,6 +37,7 @@ obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672A) += panel-novatek-nt36672a.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
 obj-$(CONFIG_DRM_PANEL_MANTIX_MLAF057WE51) += panel-mantix-mlaf057we51.o
 obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o
+obj-$(CONFIG_DRM_PANEL_ORISETECH_OTA5601A) += panel-orisetech-ota5601a.o
 obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
 obj-$(CONFIG_DRM_PANEL_OSD_OSD101T2587_53TS) += panel-osd-osd101t2587-53ts.o
 obj-$(CONFIG_DRM_PANEL_PANASONIC_VVX10F034N00) += panel-panasonic-vvx10f034n00.o

drivers/gpu/drm/panel/panel-orisetech-ota5601a.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Orisetech OTA5601A TFT LCD panel driver
+ *
+ * Copyright (C) 2021, Christophe Branchereau <cbranchereau@gmail.com>
+ */
+
+#include <linux/bits.h>
+#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.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>
+
+#define OTA5601A_CTL 0x01
+#define OTA5601A_CTL_OFF 0x00
+#define OTA5601A_CTL_ON BIT(0)
+
+struct ota5601a_panel_info {
+	const struct drm_display_mode *display_modes;
+	unsigned int num_modes;
+	u16 width_mm, height_mm;
+	u32 bus_format, bus_flags;
+};
+
+struct ota5601a {
+	struct drm_panel drm_panel;
+	struct regmap *map;
+	struct regulator *supply;
+	const struct ota5601a_panel_info *panel_info;
+
+	struct gpio_desc *reset_gpio;
+};
+
+static inline struct ota5601a *to_ota5601a(struct drm_panel *panel)
+{
+	return container_of(panel, struct ota5601a, drm_panel);
+}
+
+static const struct reg_sequence ota5601a_panel_regs[] = {
+	{ 0xfd, 0x00 }, /* Page Shift */
+	{ 0x02, 0x00 }, /* Reset */
+
+	{ 0x18, 0x00 }, /* Interface Sel: RGB 24 Bits */
+	{ 0x34, 0x20 }, /* Undocumented */
+
+	{ 0x0c, 0x01 }, /* Contrast set by CMD1 == within page 0x00 */
+	{ 0x0d, 0x48 }, /* R Brightness */
+	{ 0x0e, 0x48 }, /* G Brightness */
+	{ 0x0f, 0x48 }, /* B Brightness */
+	{ 0x07, 0x40 }, /* R Contrast */
+	{ 0x08, 0x33 }, /* G Contrast */
+	{ 0x09, 0x3a }, /* B Contrast */
+
+	{ 0x16, 0x01 }, /* NTSC Sel */
+	{ 0x19, 0x8d }, /* VBLK */
+	{ 0x1a, 0x28 }, /* HBLK */
+	{ 0x1c, 0x00 }, /* Scan Shift Dir. */
+
+	{ 0xfd, 0xc5 }, /* Page Shift */
+	{ 0x82, 0x0c }, /* PWR_CTRL Pump */
+	{ 0xa2, 0xb4 }, /* PWR_CTRL VGH/VGL */
+
+	{ 0xfd, 0xc4 }, /* Page Shift - What follows is listed as "RGB 24bit Timing Set" */
+	{ 0x82, 0x45 },
+
+	{ 0xfd, 0xc1 },
+	{ 0x91, 0x02 },
+
+	{ 0xfd, 0xc0 },
+	{ 0xa1, 0x01 },
+	{ 0xa2, 0x1f },
+	{ 0xa3, 0x0b },
+	{ 0xa4, 0x38 },
+	{ 0xa5, 0x00 },
+	{ 0xa6, 0x0a },
+	{ 0xa7, 0x38 },
+	{ 0xa8, 0x00 },
+	{ 0xa9, 0x0a },
+	{ 0xaa, 0x37 },
+
+	{ 0xfd, 0xce },
+	{ 0x81, 0x18 },
+	{ 0x82, 0x43 },
+	{ 0x83, 0x43 },
+	{ 0x91, 0x06 },
+	{ 0x93, 0x38 },
+	{ 0x94, 0x02 },
+	{ 0x95, 0x06 },
+	{ 0x97, 0x38 },
+	{ 0x98, 0x02 },
+	{ 0x99, 0x06 },
+	{ 0x9b, 0x38 },
+	{ 0x9c, 0x02 },
+
+	{ 0xfd, 0x00 }, /* Page Shift */
+};
+
+static const struct regmap_config ota5601a_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int ota5601a_prepare(struct drm_panel *drm_panel)
+{
+	struct ota5601a *panel = to_ota5601a(drm_panel);
+	int err;
+
+	err = regulator_enable(panel->supply);
+	if (err) {
+		dev_err(drm_panel->dev, "Failed to enable power supply: %d\n", err);
+		return err;
+	}
+
+	/* Reset to be held low for 10us min according to the doc, 10ms before sending commands */
+	gpiod_set_value_cansleep(panel->reset_gpio, 1);
+	usleep_range(10, 30);
+	gpiod_set_value_cansleep(panel->reset_gpio, 0);
+	usleep_range(10000, 20000);
+
+	/* Init all registers. */
+	err = regmap_multi_reg_write(panel->map, ota5601a_panel_regs,
+				     ARRAY_SIZE(ota5601a_panel_regs));
+	if (err) {
+		dev_err(drm_panel->dev, "Failed to init registers: %d\n", err);
+		goto err_disable_regulator;
+	}
+
+	msleep(120);
+
+	return 0;
+
+err_disable_regulator:
+	regulator_disable(panel->supply);
+	return err;
+}
+
+static int ota5601a_unprepare(struct drm_panel *drm_panel)
+{
+	struct ota5601a *panel = to_ota5601a(drm_panel);
+
+	gpiod_set_value_cansleep(panel->reset_gpio, 1);
+
+	regulator_disable(panel->supply);
+
+	return 0;
+}
+
+static int ota5601a_enable(struct drm_panel *drm_panel)
+{
+	struct ota5601a *panel = to_ota5601a(drm_panel);
+	int err;
+
+	err = regmap_write(panel->map, OTA5601A_CTL, OTA5601A_CTL_ON);
+
+	if (err) {
+		dev_err(drm_panel->dev, "Unable to enable panel: %d\n", err);
+		return err;
+	}
+
+	if (drm_panel->backlight) {
+		/* Wait for the picture to be ready before enabling backlight */
+		msleep(120);
+	}
+
+	return 0;
+}
+
+static int ota5601a_disable(struct drm_panel *drm_panel)
+{
+	struct ota5601a *panel = to_ota5601a(drm_panel);
+	int err;
+
+	err = regmap_write(panel->map, OTA5601A_CTL, OTA5601A_CTL_OFF);
+
+	if (err) {
+		dev_err(drm_panel->dev, "Unable to disable panel: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int ota5601a_get_modes(struct drm_panel *drm_panel,
+			      struct drm_connector *connector)
+{
+	struct ota5601a *panel = to_ota5601a(drm_panel);
+	const struct ota5601a_panel_info *panel_info = panel->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 ota5601a_funcs = {
+	.prepare	= ota5601a_prepare,
+	.unprepare	= ota5601a_unprepare,
+	.enable		= ota5601a_enable,
+	.disable	= ota5601a_disable,
+	.get_modes	= ota5601a_get_modes,
+};
+
+static int ota5601a_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct device *dev = &spi->dev;
+	struct ota5601a *panel;
+	int err;
+
+	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
+	if (!panel)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, panel);
+
+	panel->panel_info = (const struct ota5601a_panel_info *)id->driver_data;
+	if (!panel->panel_info)
+		return -EINVAL;
+
+	panel->supply = devm_regulator_get(dev, "power");
+	if (IS_ERR(panel->supply)) {
+		dev_err(dev, "Failed to get power supply\n");
+		return PTR_ERR(panel->supply);
+	}
+
+	panel->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(panel->reset_gpio)) {
+		dev_err(dev, "Failed to get reset GPIO\n");
+		return PTR_ERR(panel->reset_gpio);
+	}
+
+	spi->bits_per_word = 8;
+	spi->mode = SPI_MODE_3 | SPI_3WIRE;
+	err = spi_setup(spi);
+	if (err) {
+		dev_err(dev, "Failed to setup SPI\n");
+		return err;
+	}
+
+	panel->map = devm_regmap_init_spi(spi, &ota5601a_regmap_config);
+	if (IS_ERR(panel->map)) {
+		dev_err(dev, "Failed to init regmap\n");
+		return PTR_ERR(panel->map);
+	}
+
+	drm_panel_init(&panel->drm_panel, dev, &ota5601a_funcs,
+		       DRM_MODE_CONNECTOR_DPI);
+
+	err = drm_panel_of_backlight(&panel->drm_panel);
+	if (err) {
+		if (err != -EPROBE_DEFER)
+			dev_err(dev, "Failed to get backlight handle\n");
+		return err;
+	}
+
+	drm_panel_add(&panel->drm_panel);
+
+	return 0;
+}
+
+static void ota5601a_remove(struct spi_device *spi)
+{
+	struct ota5601a *panel = spi_get_drvdata(spi);
+
+	drm_panel_remove(&panel->drm_panel);
+
+	ota5601a_disable(&panel->drm_panel);
+	ota5601a_unprepare(&panel->drm_panel);
+}
+
+static const struct drm_display_mode gpt3_display_modes[] = {
+	{ /* 60 Hz */
+		.clock = 27000,
+		.hdisplay = 640,
+		.hsync_start = 640 + 220,
+		.hsync_end = 640 + 220 + 20,
+		.htotal = 640 + 220 + 20 + 20,
+		.vdisplay = 480,
+		.vsync_start = 480 + 7,
+		.vsync_end = 480 + 7 + 6,
+		.vtotal = 480 + 7 + 6 + 7,
+		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	},
+
+	{ /* 50 Hz */
+		.clock = 24000,
+		.hdisplay = 640,
+		.hsync_start = 640 + 280,
+		.hsync_end = 640 + 280 + 20,
+		.htotal = 640 + 280 + 20 + 20,
+		.vdisplay = 480,
+		.vsync_start = 480 + 7,
+		.vsync_end = 480 + 7 + 6,
+		.vtotal = 480 + 7 + 6 + 7,
+		.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	},
+};
+
+static const struct ota5601a_panel_info gpt3_info = {
+	.display_modes = gpt3_display_modes,
+	.num_modes = ARRAY_SIZE(gpt3_display_modes),
+	.width_mm = 71,
+	.height_mm = 51,
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
+};
+
+static const struct spi_device_id gpt3_id[] = {
+	{ "gpt3", (kernel_ulong_t)&gpt3_info },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, gpt3_id);
+
+static const struct of_device_id ota5601a_of_match[] = {
+	{ .compatible = "focaltech,gpt3" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ota5601a_of_match);
+
+static struct spi_driver ota5601a_driver = {
+	.driver = {
+		.name = "ota5601a",
+		.of_match_table = ota5601a_of_match,
+	},
+	.id_table = gpt3_id,
+	.probe = ota5601a_probe,
+	.remove = ota5601a_remove,
+};
+
+module_spi_driver(ota5601a_driver);
+
+MODULE_AUTHOR("Christophe Branchereau <cbranchereau@gmail.com>");
+MODULE_LICENSE("GPL");