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From: dillon.minfei@gmail.com
To: thierry.reding@gmail.com, sam@ravnborg.org, airlied@linux.ie,
 daniel@ffwll.ch, alexandre.torgue@st.com
Subject: [PATCH 3/4] drm/panel: Add Ilitek ILI9341 driver
Date: Wed,  6 May 2020 14:37:17 +0800
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From: dillon min <dillon.minfei@gmail.com>

This adds support for the Ilitek ILI9341 QVGA (240x320)
TFT panel driver.

This panel driver supports parallel RGB input.

The controller is combined with a physical panel and
configured through the device tree.

Signed-off-by: dillon min <dillon.minfei@gmail.com>
---
 drivers/gpu/drm/panel/Kconfig                |   8 +
 drivers/gpu/drm/panel/Makefile               |   1 +
 drivers/gpu/drm/panel/panel-ilitek-ili9341.c | 513 +++++++++++++++++++++++++++
 3 files changed, 522 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9341.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index a1723c1..e42692c 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -95,6 +95,14 @@ config DRM_PANEL_ILITEK_IL9322
 	  Say Y here if you want to enable support for Ilitek IL9322
 	  QVGA (320x240) RGB, YUV and ITU-T BT.656 panels.
 
+config DRM_PANEL_ILITEK_IL9341
+	tristate "Ilitek ILI9341 240x320 QVGA panels"
+	depends on OF && SPI
+	select REGMAP
+	help
+	  Say Y here if you want to enable support for Ilitek IL9341
+	  QVGA (240x320) RGB panels.
+
 config DRM_PANEL_ILITEK_ILI9881C
 	tristate "Ilitek ILI9881C-based panels"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 96a883c..d123543 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) += panel-elida-kd35t133.o
 obj-$(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-$(CONFIG_DRM_PANEL_ILITEK_IL9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
new file mode 100644
index 0000000..e458677
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
@@ -0,0 +1,513 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ilitek ILI9341 TFT LCD drm_panel driver.
+ *
+ * This panel can be configured to support:
+ * - 16-bit parallel RGB interface
+ *
+ * Copyright (C) 2020 Dillon Min <dillon.minfei@gmail.com>
+ * Derived from drivers/drm/gpu/panel/panel-ilitek-ili9322.c
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+#include <video/mipi_display.h>
+#include <video/of_videomode.h>
+#include <video/videomode.h>
+
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+#define DEFAULT_SPI_SPEED	10000000
+
+#define ILI9341_SLEEP_OUT            0x11   /* Sleep out register */
+#define ILI9341_GAMMA                0x26   /* Gamma register */
+#define ILI9341_DISPLAY_OFF          0x28   /* Display off register */
+#define ILI9341_DISPLAY_ON           0x29   /* Display on register */
+#define ILI9341_COLUMN_ADDR          0x2A   /* Colomn address register */
+#define ILI9341_PAGE_ADDR            0x2B   /* Page address register */
+#define ILI9341_GRAM                 0x2C   /* GRAM register */
+#define ILI9341_MAC                  0x36   /* Memory Access Control register*/
+#define ILI9341_PIXEL_FORMAT         0x3A   /* Pixel Format register */
+#define ILI9341_WDB                  0x51   /* Write Brightness Display
+					     * register
+					     */
+#define ILI9341_WCD                  0x53   /* Write Control Display
+					     * register
+					     */
+#define ILI9341_RGB_INTERFACE        0xB0   /* RGB Interface Signal Control */
+#define ILI9341_FRC                  0xB1   /* Frame Rate Control register */
+#define ILI9341_BPC                  0xB5   /* Blanking Porch Control
+					     * register
+					     */
+#define ILI9341_DFC                  0xB6   /* Display Function Control
+					     * register
+					     */
+#define ILI9341_POWER1               0xC0   /* Power Control 1 register */
+#define ILI9341_POWER2               0xC1   /* Power Control 2 register */
+#define ILI9341_VCOM1                0xC5   /* VCOM Control 1 register */
+#define ILI9341_VCOM2                0xC7   /* VCOM Control 2 register */
+#define ILI9341_POWERA               0xCB   /* Power control A register */
+#define ILI9341_POWERB               0xCF   /* Power control B register */
+#define ILI9341_PGAMMA               0xE0   /* Positive Gamma Correction
+					     * register
+					     */
+#define ILI9341_NGAMMA               0xE1   /* Negative Gamma Correction
+					     * register
+					     */
+#define ILI9341_DTCA                 0xE8   /* Driver timing control A */
+#define ILI9341_DTCB                 0xEA   /* Driver timing control B */
+#define ILI9341_POWER_SEQ            0xED   /* Power on sequence register */
+#define ILI9341_3GAMMA_EN            0xF2   /* 3 Gamma enable register */
+#define ILI9341_INTERFACE            0xF6   /* Interface control register */
+#define ILI9341_PRC                  0xF7   /* Pump ratio control register */
+
+static u8 ili9341_cmd0[] = {0xca, 0xc3, 0x08, 0x50};
+static u8 ili9341_powerb[] = {ILI9341_POWERB, 0x00, 0xc1, 0x30};
+static u8 ili9341_power_seq[] = {ILI9341_POWER_SEQ, 0x64, 0x03, 0x12, 0x81};
+static u8 ili9341_dtca[] = {ILI9341_DTCA, 0x85, 0x00, 0x78};
+static u8 ili9341_powera[] = {ILI9341_POWERA, 0x39, 0x2c, 0x00, 0x34, 0x02};
+static u8 ili9341_prc[] = {ILI9341_PRC, 0x20};
+static u8 ili9341_dtcb[] = {ILI9341_DTCB, 0x00, 0x00};
+static u8 ili9341_frc[] = {ILI9341_FRC, 0x00, 0x1b};
+static u8 ili9341_dfc1[] = {ILI9341_DFC, 0x0a, 0xa2};
+static u8 ili9341_power1[] = {ILI9341_POWER1, 0x10};
+static u8 ili9341_power2[] = {ILI9341_POWER2, 0x10};
+static u8 ili9341_vcom1[] = {ILI9341_VCOM1, 0x45, 0x15};
+static u8 ili9341_vcom2[] = {ILI9341_VCOM2, 0x90};
+static u8 ili9341_mac[] = {ILI9341_MAC, 0xc8};
+static u8 ili9341_gamma_en[] = {ILI9341_3GAMMA_EN, 0x00};
+static u8 ili9341_rgb_intr[] = {ILI9341_RGB_INTERFACE, 0xc2};
+static u8 ili9341_dfc2[] = {ILI9341_DFC, 0x0a, 0xa7, 0x27, 0x04};
+static u8 ili9341_column_addr[] = {ILI9341_COLUMN_ADDR, 0x00, 0x00, 0x00,
+					0xef};
+static u8 ili9341_page_addr[] = {ILI9341_PAGE_ADDR, 0x00, 0x00, 0x01, 0x3f};
+static u8 ili9341_intr[] = {ILI9341_INTERFACE, 0x01, 0x00, 0x06};
+static u8 ili9341_gamma[] = {ILI9341_GAMMA, 0x01};
+static u8 ili9341_pgamma[] = {ILI9341_PGAMMA, 0x0f, 0x29, 0x24, 0x0c, 0x0e,
+				0x09, 0x4e, 0x78,
+				0x3c, 0x09, 0x13, 0x05,	0x17, 0x11, 0x00};
+static u8 ili9341_ngamma[] = {ILI9341_NGAMMA, 0x00, 0x16, 0x1b, 0x04, 0x11,
+				0x07, 0x31, 0x33,
+				0x42, 0x05, 0x0c, 0x0a, 0x28, 0x2f, 0x0f};
+static u8 ili9341_gram[] = {ILI9341_GRAM};
+static u8 ili9341_sleep_out[] = {ILI9341_SLEEP_OUT};
+static u8 ili9341_display_on[] = {ILI9341_DISPLAY_ON};
+static u8 ili9341_display_off[] = {ILI9341_DISPLAY_OFF};
+
+/**
+ * enum ili9341_input - the format of the incoming signal to the panel
+ *
+ * The panel can be connected to various input streams and four of them can
+ * be selected by electronic straps on the display. However it is possible
+ * to select another mode or override the electronic default with this
+ * setting.
+ */
+enum ili9341_input {
+	ILI9341_INPUT_PRGB_THROUGH = 0x0,
+	ILI9341_INPUT_PRGB_ALIGNED = 0x1,
+	ILI9341_INPUT_UNKNOWN = 0xf,
+};
+
+/**
+ * struct ili9341_config - the system specific ILI9341 configuration
+ * @width_mm: physical panel width [mm]
+ * @height_mm: physical panel height [mm]
+ * @input: the input/entry type used in this system, if this is set to
+ * ILI9341_INPUT_UNKNOWN the driver will try to figure it out by probing
+ * the hardware
+ * @dclk_active_high: data/pixel clock active high, data will be clocked
+ * in on the rising edge of the DCLK (this is usually the case).
+ * @de_active_high: DE (data entry) is active high
+ * @hsync_active_high: HSYNC is active high
+ * @vsync_active_high: VSYNC is active high
+ */
+struct ili9341_config {
+	u32 width_mm;
+	u32 height_mm;
+	enum ili9341_input input;
+	bool dclk_active_high;
+	bool de_active_high;
+	bool hsync_active_high;
+	bool vsync_active_high;
+};
+
+struct ili9341 {
+	struct device *dev;
+	const struct ili9341_config *conf;
+	struct drm_panel panel;
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *dc_gpio;
+	enum ili9341_input input;
+	struct videomode vm;
+};
+
+static inline struct ili9341 *panel_to_ili9341(struct drm_panel *panel)
+{
+	return container_of(panel, struct ili9341, panel);
+}
+
+int ili9341_spi_transfer(struct spi_device *spi, u32 speed_hz,
+			  u8 bpw, const void *buf, size_t len)
+{
+	size_t max_chunk = spi_max_transfer_size(spi);
+	struct spi_transfer tr = {
+		.bits_per_word = bpw,
+		.speed_hz = speed_hz,
+		.len = len,
+	};
+	struct spi_message m;
+	size_t chunk;
+	int ret;
+
+	spi_message_init_with_transfers(&m, &tr, 1);
+
+	while (len) {
+		chunk = min(len, max_chunk);
+
+		tr.tx_buf = buf;
+		tr.len = chunk;
+		buf += chunk;
+		len -= chunk;
+
+		ret = spi_sync(spi, &m);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+static int ili9341_spi_write(struct ili9341 *ili, const void *data,
+				    size_t count)
+{
+	struct spi_device *spi = to_spi_device(ili->dev);
+	int ret = 0;
+
+	gpiod_set_value_cansleep(ili->dc_gpio, 0);
+
+	ret = ili9341_spi_transfer(spi, DEFAULT_SPI_SPEED, 8, data+0, 1);
+	if (ret || count == 1)
+		return ret;
+
+	gpiod_set_value_cansleep(ili->dc_gpio, 1);
+
+	return ili9341_spi_transfer(spi, DEFAULT_SPI_SPEED, 8,
+		data+1, count-1);
+}
+
+static int ili9341_init(struct ili9341 *ili)
+{
+	ili9341_spi_write(ili, ili9341_cmd0,
+				sizeof(ili9341_cmd0));
+	ili9341_spi_write(ili, ili9341_powerb,
+				sizeof(ili9341_powerb));
+	ili9341_spi_write(ili, ili9341_power_seq,
+				sizeof(ili9341_power_seq));
+	ili9341_spi_write(ili, ili9341_dtca,
+				sizeof(ili9341_dtca));
+	ili9341_spi_write(ili, ili9341_powera,
+				sizeof(ili9341_powera));
+	ili9341_spi_write(ili, ili9341_prc,
+				sizeof(ili9341_prc));
+	ili9341_spi_write(ili, ili9341_dtcb,
+				sizeof(ili9341_dtcb));
+	ili9341_spi_write(ili, ili9341_frc,
+				sizeof(ili9341_frc));
+	ili9341_spi_write(ili, ili9341_dfc1,
+				sizeof(ili9341_dfc1));
+	ili9341_spi_write(ili, ili9341_power1,
+				sizeof(ili9341_power1));
+	ili9341_spi_write(ili, ili9341_power2,
+				sizeof(ili9341_power2));
+	ili9341_spi_write(ili, ili9341_vcom1,
+				sizeof(ili9341_vcom1));
+	ili9341_spi_write(ili, ili9341_vcom2,
+				sizeof(ili9341_vcom2));
+	ili9341_spi_write(ili, ili9341_mac,
+				sizeof(ili9341_mac));
+	ili9341_spi_write(ili, ili9341_gamma_en,
+				sizeof(ili9341_gamma_en));
+	ili9341_spi_write(ili, ili9341_rgb_intr,
+				sizeof(ili9341_rgb_intr));
+	ili9341_spi_write(ili, ili9341_dfc2,
+				sizeof(ili9341_dfc2));
+	ili9341_spi_write(ili, ili9341_column_addr,
+				sizeof(ili9341_column_addr));
+	ili9341_spi_write(ili, ili9341_page_addr,
+				sizeof(ili9341_page_addr));
+	ili9341_spi_write(ili, ili9341_intr,
+				sizeof(ili9341_intr));
+	ili9341_spi_write(ili, ili9341_gram,
+				sizeof(ili9341_gram));
+	msleep(200);
+	ili9341_spi_write(ili, ili9341_gamma,
+				sizeof(ili9341_gamma));
+	ili9341_spi_write(ili, ili9341_pgamma,
+				sizeof(ili9341_pgamma));
+	ili9341_spi_write(ili, ili9341_ngamma,
+				sizeof(ili9341_ngamma));
+	ili9341_spi_write(ili, ili9341_sleep_out,
+				sizeof(ili9341_sleep_out));
+	msleep(200);
+	ili9341_spi_write(ili, ili9341_display_on,
+				sizeof(ili9341_display_on));
+	ili9341_spi_write(ili, ili9341_gram,
+				sizeof(ili9341_gram));
+
+	dev_info(ili->dev, "initialized display\n");
+
+	return 0;
+}
+
+/*
+ * This power-on sequence if from the datasheet, page 57.
+ */
+static int ili9341_power_on(struct ili9341 *ili)
+{
+	/* Assert RESET */
+	gpiod_set_value(ili->reset_gpio, 1);
+
+	msleep(20);
+
+	/* De-assert RESET */
+	gpiod_set_value(ili->reset_gpio, 0);
+
+	msleep(10);
+
+	return 0;
+}
+
+static int ili9341_power_off(struct ili9341 *ili)
+{
+	return 0;
+}
+
+static int ili9341_disable(struct drm_panel *panel)
+{
+	struct ili9341 *ili = panel_to_ili9341(panel);
+
+	ili9341_spi_write(ili, ili9341_display_off,
+				sizeof(ili9341_display_off));
+
+	return 0;
+}
+
+static int ili9341_unprepare(struct drm_panel *panel)
+{
+	struct ili9341 *ili = panel_to_ili9341(panel);
+
+	return ili9341_power_off(ili);
+}
+
+static int ili9341_prepare(struct drm_panel *panel)
+{
+	struct ili9341 *ili = panel_to_ili9341(panel);
+	int ret;
+
+	ret = ili9341_power_on(ili);
+	if (ret < 0)
+		return ret;
+
+	ret = ili9341_init(ili);
+	if (ret < 0)
+		ili9341_unprepare(panel);
+
+	return ret;
+}
+
+static int ili9341_enable(struct drm_panel *panel)
+{
+	struct ili9341 *ili = panel_to_ili9341(panel);
+
+	ili9341_spi_write(ili, ili9341_display_on,
+				sizeof(ili9341_display_on));
+
+	return 0;
+}
+
+/* This is the only mode listed for parallel RGB in the datasheet */
+static const struct drm_display_mode prgb_320x240_mode = {
+	.clock = 6100,
+	.hdisplay = 240,
+	.hsync_start = 240 + 10,
+	.hsync_end = 240 + 10 + 10,
+	.htotal = 280,
+	.vdisplay = 320,
+	.vsync_start = 320 + 4,
+	.vsync_end = 320 + 4 + 2,
+	.vtotal = 328,
+	.vrefresh = 60,
+	.flags = 0,
+};
+
+static int ili9341_get_modes(struct drm_panel *panel,
+				struct drm_connector *connector)
+{
+	struct ili9341 *ili = panel_to_ili9341(panel);
+	struct drm_device *drm = connector->dev;
+	struct drm_display_mode *mode;
+	struct drm_display_info *info;
+
+	info = &connector->display_info;
+	info->width_mm = ili->conf->width_mm;
+	info->height_mm = ili->conf->height_mm;
+	if (ili->conf->dclk_active_high)
+		info->bus_flags |= DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE;
+	else
+		info->bus_flags |= DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
+
+	if (ili->conf->de_active_high)
+		info->bus_flags |= DRM_BUS_FLAG_DE_HIGH;
+	else
+		info->bus_flags |= DRM_BUS_FLAG_DE_LOW;
+
+	switch (ili->input) {
+	case ILI9341_INPUT_PRGB_THROUGH:
+	case ILI9341_INPUT_PRGB_ALIGNED:
+		mode = drm_mode_duplicate(drm, &prgb_320x240_mode);
+		break;
+	default:
+		mode = NULL;
+		break;
+	}
+	if (!mode) {
+		DRM_ERROR("bad mode or failed to add mode\n");
+		return -EINVAL;
+	}
+	drm_mode_set_name(mode);
+	/*
+	 * This is the preferred mode because most people are going
+	 * to want to use the display with VGA type graphics.
+	 */
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+
+	/* Set up the polarity */
+	if (ili->conf->hsync_active_high)
+		mode->flags |= DRM_MODE_FLAG_PHSYNC;
+	else
+		mode->flags |= DRM_MODE_FLAG_NHSYNC;
+	if (ili->conf->vsync_active_high)
+		mode->flags |= DRM_MODE_FLAG_PVSYNC;
+	else
+		mode->flags |= DRM_MODE_FLAG_NVSYNC;
+
+	mode->width_mm = ili->conf->width_mm;
+	mode->height_mm = ili->conf->height_mm;
+	drm_mode_probed_add(connector, mode);
+
+	return 1; /* Number of modes */
+}
+
+static const struct drm_panel_funcs ili9341_drm_funcs = {
+	.disable = ili9341_disable,
+	.unprepare = ili9341_unprepare,
+	.prepare = ili9341_prepare,
+	.enable = ili9341_enable,
+	.get_modes = ili9341_get_modes,
+};
+
+static int ili9341_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct ili9341 *ili;
+	int ret;
+
+	ili = devm_kzalloc(dev, sizeof(struct ili9341), GFP_KERNEL);
+	if (!ili)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, ili);
+
+	ili->dev = dev;
+	/*
+	 * Every new incarnation of this display must have a unique
+	 * data entry for the system in this driver.
+	 */
+	ili->conf = of_device_get_match_data(dev);
+	if (!ili->conf) {
+		dev_err(dev, "missing device configuration\n");
+		return -ENODEV;
+	}
+
+	ili->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+		GPIOD_OUT_HIGH);
+	if (IS_ERR(ili->reset_gpio)) {
+		dev_err(dev, "failed to get RESET GPIO\n");
+		return PTR_ERR(ili->reset_gpio);
+	}
+
+	ili->dc_gpio = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
+	if (IS_ERR(ili->dc_gpio)) {
+		dev_err(dev, "failed to get DC GPIO\n");
+		return PTR_ERR(ili->dc_gpio);
+	}
+
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(dev, "spi setup failed.\n");
+		return ret;
+	}
+
+	ili->input = ili->conf->input;
+
+	drm_panel_init(&ili->panel, dev, &ili9341_drm_funcs,
+		       DRM_MODE_CONNECTOR_DPI);
+
+	return drm_panel_add(&ili->panel);
+}
+
+static int ili9341_remove(struct spi_device *spi)
+{
+	struct ili9341 *ili = spi_get_drvdata(spi);
+
+	ili9341_power_off(ili);
+	drm_panel_remove(&ili->panel);
+
+	return 0;
+}
+
+/*
+ * The Stm32f429-disco board has a panel ili9341 connected to ltdc controller
+ */
+static const struct ili9341_config ili9341_data = {
+	.width_mm = 65,
+	.height_mm = 50,
+	.input = ILI9341_INPUT_PRGB_THROUGH,
+	.dclk_active_high = true,
+	.de_active_high = false,
+	.hsync_active_high = false,
+	.vsync_active_high = false,
+};
+
+static const struct of_device_id ili9341_of_match[] = {
+	{
+		.compatible = "stm32f429-disco,ltdc-panel",
+		.data = &ili9341_data,
+	},
+	{
+		.compatible = "ilitek,ili9341",
+		.data = NULL,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ili9341_of_match);
+
+static struct spi_driver ili9341_driver = {
+	.probe = ili9341_probe,
+	.remove = ili9341_remove,
+	.driver = {
+		.name = "panel-ilitek-ili9341",
+		.of_match_table = ili9341_of_match,
+	},
+};
+module_spi_driver(ili9341_driver);
+
+MODULE_AUTHOR("Dillon Min <dillon.minfei@gmail.com>");
+MODULE_DESCRIPTION("ILI9341 LCD panel driver");
+MODULE_LICENSE("GPL v2");