From 6e9d09063a883bd69c84a95f6e854a7dbe7720af Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Tue, 1 Feb 2022 15:27:01 +0000
Subject: [PATCH] drm/panel/panel-sitronix-st7701: Support SPI config
 and RGB data

The ST7701 supports numerous different interface mechanisms for
MIPI DSI, RGB, or SPI. The driver was only implementing DSI input,
so add RGB parallel input with SPI configuration.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/panel/panel-sitronix-st7701.c | 382 ++++++++++++++++--
 1 file changed, 359 insertions(+), 23 deletions(-)

--- a/drivers/gpu/drm/panel/panel-sitronix-st7701.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7701.c
@@ -7,15 +7,20 @@
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_modes.h>
 #include <drm/drm_panel.h>
+#include <drm/drm_print.h>
 
 #include <linux/gpio/consumer.h>
 #include <linux/delay.h>
+#include <linux/media-bus-format.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
 
 #include <video/mipi_display.h>
 
+#define SPI_DATA_FLAG			0x100
+
 /* Command2 BKx selection command */
 #define DSI_CMD2BKX_SEL			0xFF
 
@@ -46,9 +51,14 @@
  * 11 = CMD2BK1, Command2 BK1
  * 00 = Command2 disable
  */
+#define DSI_CMD2BK3_SEL			0x13
 #define DSI_CMD2BK1_SEL			0x11
 #define DSI_CMD2BK0_SEL			0x10
 #define DSI_CMD2BKX_SEL_NONE		0x00
+#define SPI_CMD2BK3_SEL			(SPI_DATA_FLAG | DSI_CMD2BK3_SEL)
+#define SPI_CMD2BK1_SEL			(SPI_DATA_FLAG | DSI_CMD2BK1_SEL)
+#define SPI_CMD2BK0_SEL			(SPI_DATA_FLAG | DSI_CMD2BK0_SEL)
+#define SPI_CMD2BKX_SEL_NONE		(SPI_DATA_FLAG | DSI_CMD2BKX_SEL_NONE)
 
 /* Command2, BK0 bytes */
 #define DSI_LINESET_LINE		0x69
@@ -86,19 +96,34 @@
 #define DSI_MIPISET1_EOT_EN		BIT(3)
 #define DSI_CMD2_BK1_MIPISET1_SET	(BIT(7) | DSI_MIPISET1_EOT_EN)
 
+struct st7701;
+
+enum st7701_ctrl_if {
+	ST7701_CTRL_DSI,
+	ST7701_CTRL_SPI,
+};
+
 struct st7701_panel_desc {
 	const struct drm_display_mode *mode;
 	unsigned int lanes;
 	unsigned long flags;
 	enum mipi_dsi_pixel_format format;
+	u32 mediabus_format;
 	const char *const *supply_names;
 	unsigned int num_supplies;
 	unsigned int panel_sleep_delay;
+	void (*init_sequence)(struct st7701 *st7701);
+	unsigned int conn_type;
+	enum st7701_ctrl_if interface;
+	u32 bus_flags;
 };
 
 struct st7701 {
 	struct drm_panel panel;
 	struct mipi_dsi_device *dsi;
+	struct spi_device *spi;
+	const struct device *dev;
+
 	const struct st7701_panel_desc *desc;
 
 	struct regulator_bulk_data *supplies;
@@ -123,7 +148,23 @@ static inline int st7701_dsi_write(struc
 		st7701_dsi_write(st7701, d, ARRAY_SIZE(d));	\
 	}
 
-static void st7701_init_sequence(struct st7701 *st7701)
+#define ST7701_SPI(st7701, seq...)				\
+	{							\
+		const u16 d[] = { seq };			\
+		struct spi_transfer xfer = { };			\
+		struct spi_message spi;				\
+								\
+		spi_message_init(&spi);				\
+								\
+		xfer.tx_buf = d;				\
+		xfer.bits_per_word = 9;				\
+		xfer.len = sizeof(u16) * ARRAY_SIZE(d);		\
+								\
+		spi_message_add_tail(&xfer, &spi);		\
+		spi_sync((st7701)->spi, &spi);			\
+	}
+
+static void ts8550b_init_sequence(struct st7701 *st7701)
 {
 	const struct drm_display_mode *mode = st7701->desc->mode;
 
@@ -194,6 +235,111 @@ static void st7701_init_sequence(struct
 		   0x77, 0x01, 0x00, 0x00, DSI_CMD2BKX_SEL_NONE);
 }
 
+static void txw210001b0_init_sequence(struct st7701 *st7701)
+{
+	ST7701_SPI(st7701, MIPI_DCS_SOFT_RESET);
+
+	usleep_range(5000, 7000);
+
+	ST7701_SPI(st7701, DSI_CMD2BKX_SEL,
+		   0x177, 0x101, 0x100, 0x100, SPI_CMD2BK0_SEL);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK0_LNESET, 0x13B, 0x100);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK0_PORCTRL, 0x10B, 0x102);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK0_INVSEL, 0x100, 0x102);
+
+	ST7701_SPI(st7701, 0xCC, 0x110);
+
+	/*
+	 * Gamma option B:
+	 * Positive Voltage Gamma Control
+	 */
+	ST7701_SPI(st7701, DSI_CMD2_BK0_PVGAMCTRL,
+		   0x102, 0x113, 0x11B, 0x10D, 0x110, 0x105, 0x108, 0x107,
+		   0x107, 0x124, 0x104, 0x111, 0x10E, 0x12C, 0x133, 0x11D);
+
+	/* Negative Voltage Gamma Control */
+	ST7701_SPI(st7701, DSI_CMD2_BK0_NVGAMCTRL,
+		   0x105, 0x113, 0x11B, 0x10D, 0x111, 0x105, 0x108, 0x107,
+		   0x107, 0x124, 0x104, 0x111, 0x10E, 0x12C, 0x133, 0x11D);
+
+	ST7701_SPI(st7701, DSI_CMD2BKX_SEL,
+		   0x177, 0x101, 0x100, 0x100, SPI_CMD2BK1_SEL);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_VRHS, 0x15D);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_VCOM, 0x143);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_VGHSS, 0x181);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_TESTCMD, 0x180);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_VGLS, 0x143);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_PWCTLR1, 0x185);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_PWCTLR2, 0x120);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_SPD1, 0x178);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_SPD2, 0x178);
+
+	ST7701_SPI(st7701, DSI_CMD2_BK1_MIPISET1, 0x188);
+
+	ST7701_SPI(st7701, 0xE0, 0x100, 0x100, 0x102);
+
+	ST7701_SPI(st7701, 0xE1,
+		   0x103, 0x1A0, 0x100, 0x100, 0x104, 0x1A0, 0x100, 0x100,
+		   0x100, 0x120, 0x120);
+
+	ST7701_SPI(st7701, 0xE2,
+		   0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
+		   0x100, 0x100, 0x100, 0x100, 0x100);
+
+	ST7701_SPI(st7701, 0xE3, 0x100, 0x100, 0x111, 0x100);
+
+	ST7701_SPI(st7701, 0xE4, 0x122, 0x100);
+
+	ST7701_SPI(st7701, 0xE5,
+		   0x105, 0x1EC, 0x1A0, 0x1A0, 0x107, 0x1EE, 0x1A0, 0x1A0,
+		   0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100);
+
+	ST7701_SPI(st7701, 0xE6, 0x100, 0x100, 0x111, 0x100);
+
+	ST7701_SPI(st7701, 0xE7, 0x122, 0x100);
+
+	ST7701_SPI(st7701, 0xE8,
+		   0x106, 0x1ED, 0x1A0, 0x1A0, 0x108, 0x1EF, 0x1A0, 0x1A0,
+		   0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100);
+
+	ST7701_SPI(st7701, 0xEB,
+		   0x100, 0x100, 0x140, 0x140, 0x100, 0x100, 0x100);
+
+	ST7701_SPI(st7701, 0xED,
+		   0x1FF, 0x1FF, 0x1FF, 0x1BA, 0x10A, 0x1BF, 0x145, 0x1FF,
+		   0x1FF, 0x154, 0x1FB, 0x1A0, 0x1AB, 0x1FF, 0x1FF, 0x1FF);
+
+	ST7701_SPI(st7701, 0xEF, 0x110, 0x10D, 0x104, 0x108, 0x13F, 0x11F);
+
+	ST7701_SPI(st7701, DSI_CMD2BKX_SEL,
+		   0x177, 0x101, 0x100, 0x100, SPI_CMD2BK3_SEL);
+
+	ST7701_SPI(st7701, 0xEF, 0x108);
+
+	ST7701_SPI(st7701, DSI_CMD2BKX_SEL,
+		   0x177, 0x101, 0x100, 0x100, SPI_CMD2BKX_SEL_NONE);
+
+	ST7701_SPI(st7701, 0xCD, 0x108);  /* RGB format COLCTRL */
+
+	ST7701_SPI(st7701, 0x36, 0x108); /* MadCtl */
+
+	ST7701_SPI(st7701, 0x3A, 0x166);  /* Colmod */
+
+	ST7701_SPI(st7701, MIPI_DCS_EXIT_SLEEP_MODE);
+}
+
 static int st7701_prepare(struct drm_panel *panel)
 {
 	struct st7701 *st7701 = panel_to_st7701(panel);
@@ -210,7 +356,7 @@ static int st7701_prepare(struct drm_pan
 	gpiod_set_value(st7701->reset, 1);
 	msleep(150);
 
-	st7701_init_sequence(st7701);
+	st7701->desc->init_sequence(st7701);
 
 	return 0;
 }
@@ -219,7 +365,15 @@ static int st7701_enable(struct drm_pane
 {
 	struct st7701 *st7701 = panel_to_st7701(panel);
 
-	ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_ON, 0x00);
+	switch (st7701->desc->interface) {
+	case ST7701_CTRL_DSI:
+		ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_ON, 0x00);
+		break;
+	case ST7701_CTRL_SPI:
+		ST7701_SPI(st7701, MIPI_DCS_SET_DISPLAY_ON);
+		msleep(30);
+		break;
+	}
 
 	return 0;
 }
@@ -228,7 +382,14 @@ static int st7701_disable(struct drm_pan
 {
 	struct st7701 *st7701 = panel_to_st7701(panel);
 
-	ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_OFF, 0x00);
+	switch (st7701->desc->interface) {
+	case ST7701_CTRL_DSI:
+		ST7701_DSI(st7701, MIPI_DCS_SET_DISPLAY_OFF, 0x00);
+		break;
+	case ST7701_CTRL_SPI:
+		ST7701_SPI(st7701, MIPI_DCS_SET_DISPLAY_OFF);
+		break;
+	}
 
 	return 0;
 }
@@ -237,7 +398,14 @@ static int st7701_unprepare(struct drm_p
 {
 	struct st7701 *st7701 = panel_to_st7701(panel);
 
-	ST7701_DSI(st7701, MIPI_DCS_ENTER_SLEEP_MODE, 0x00);
+	switch (st7701->desc->interface) {
+	case ST7701_CTRL_DSI:
+		ST7701_DSI(st7701, MIPI_DCS_ENTER_SLEEP_MODE, 0x00);
+		break;
+	case ST7701_CTRL_SPI:
+		ST7701_SPI(st7701, MIPI_DCS_ENTER_SLEEP_MODE);
+		break;
+	}
 
 	msleep(st7701->sleep_delay);
 
@@ -268,7 +436,7 @@ static int st7701_get_modes(struct drm_p
 
 	mode = drm_mode_duplicate(connector->dev, desc_mode);
 	if (!mode) {
-		dev_err(&st7701->dsi->dev, "failed to add mode %ux%u@%u\n",
+		dev_err(st7701->dev, "failed to add mode %ux%u@%u\n",
 			desc_mode->hdisplay, desc_mode->vdisplay,
 			drm_mode_vrefresh(desc_mode));
 		return -ENOMEM;
@@ -277,9 +445,18 @@ static int st7701_get_modes(struct drm_p
 	drm_mode_set_name(mode);
 	drm_mode_probed_add(connector, mode);
 
+	if (st7701->desc->mediabus_format)
+		drm_display_info_set_bus_formats(&connector->display_info,
+						 &st7701->desc->mediabus_format,
+						 1);
+	connector->display_info.bus_flags = 0;
+
 	connector->display_info.width_mm = desc_mode->width_mm;
 	connector->display_info.height_mm = desc_mode->height_mm;
 
+	if (st7701->desc->bus_flags)
+		connector->display_info.bus_flags = st7701->desc->bus_flags;
+
 	return 1;
 }
 
@@ -323,24 +500,68 @@ static const struct st7701_panel_desc ts
 	.supply_names = ts8550b_supply_names,
 	.num_supplies = ARRAY_SIZE(ts8550b_supply_names),
 	.panel_sleep_delay = 80, /* panel need extra 80ms for sleep out cmd */
+	.init_sequence = ts8550b_init_sequence,
+	.conn_type = DRM_MODE_CONNECTOR_DSI,
+	.interface = ST7701_CTRL_DSI,
 };
 
-static int st7701_dsi_probe(struct mipi_dsi_device *dsi)
+static const struct drm_display_mode txw210001b0_mode = {
+	.clock		= 19200,
+
+	.hdisplay	= 480,
+	.hsync_start	= 480 + 10,
+	.hsync_end	= 480 + 10 + 16,
+	.htotal		= 480 + 10 + 16 + 56,
+
+	.vdisplay	= 480,
+	.vsync_start	= 480 + 15,
+	.vsync_end	= 480 + 15 + 60,
+	.vtotal		= 480 + 15 + 60 + 15,
+
+	.width_mm	= 53,
+	.height_mm	= 53,
+	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static const struct st7701_panel_desc txw210001b0_desc = {
+	.mode = &txw210001b0_mode,
+	.mediabus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.supply_names = ts8550b_supply_names,
+	.num_supplies = ARRAY_SIZE(ts8550b_supply_names),
+	.init_sequence = txw210001b0_init_sequence,
+	.conn_type = DRM_MODE_CONNECTOR_DPI,
+	.interface = ST7701_CTRL_SPI,
+	.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
+};
+
+static const struct st7701_panel_desc hyperpixel2r_desc = {
+	.mode = &txw210001b0_mode,
+	.mediabus_format = MEDIA_BUS_FMT_RGB666_1X24_CPADHI,
+	.supply_names = ts8550b_supply_names,
+	.num_supplies = ARRAY_SIZE(ts8550b_supply_names),
+	.init_sequence = txw210001b0_init_sequence,
+	.conn_type = DRM_MODE_CONNECTOR_DPI,
+	.interface = ST7701_CTRL_SPI,
+	.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
+};
+
+static int st7701_probe(struct device *dev, struct st7701 **ret_st7701)
 {
 	const struct st7701_panel_desc *desc;
 	struct st7701 *st7701;
 	int ret, i;
 
-	st7701 = devm_kzalloc(&dsi->dev, sizeof(*st7701), GFP_KERNEL);
+	st7701 = devm_kzalloc(dev, sizeof(*st7701), GFP_KERNEL);
 	if (!st7701)
 		return -ENOMEM;
 
-	desc = of_device_get_match_data(&dsi->dev);
-	dsi->mode_flags = desc->flags;
-	dsi->format = desc->format;
-	dsi->lanes = desc->lanes;
+	desc = of_device_get_match_data(dev);
+	if (!desc)
+		return -EINVAL;
 
-	st7701->supplies = devm_kcalloc(&dsi->dev, desc->num_supplies,
+	st7701->supplies = devm_kcalloc(dev, desc->num_supplies,
 					sizeof(*st7701->supplies),
 					GFP_KERNEL);
 	if (!st7701->supplies)
@@ -349,19 +570,19 @@ static int st7701_dsi_probe(struct mipi_
 	for (i = 0; i < desc->num_supplies; i++)
 		st7701->supplies[i].supply = desc->supply_names[i];
 
-	ret = devm_regulator_bulk_get(&dsi->dev, desc->num_supplies,
+	ret = devm_regulator_bulk_get(dev, desc->num_supplies,
 				      st7701->supplies);
 	if (ret < 0)
 		return ret;
 
-	st7701->reset = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW);
+	st7701->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(st7701->reset)) {
-		dev_err(&dsi->dev, "Couldn't get our reset GPIO\n");
+		dev_err(dev, "Couldn't get our reset GPIO\n");
 		return PTR_ERR(st7701->reset);
 	}
 
-	drm_panel_init(&st7701->panel, &dsi->dev, &st7701_funcs,
-		       DRM_MODE_CONNECTOR_DSI);
+	drm_panel_init(&st7701->panel, dev, &st7701_funcs,
+		       desc->conn_type);
 
 	/**
 	 * Once sleep out has been issued, ST7701 IC required to wait 120ms
@@ -380,9 +601,30 @@ static int st7701_dsi_probe(struct mipi_
 
 	drm_panel_add(&st7701->panel);
 
+	st7701->desc = desc;
+	st7701->dev = dev;
+
+	*ret_st7701 = st7701;
+
+	return 0;
+}
+
+static int st7701_dsi_probe(struct mipi_dsi_device *dsi)
+{
+	struct st7701 *st7701;
+	int ret;
+
+	ret = st7701_probe(&dsi->dev, &st7701);
+
+	if (ret)
+		return ret;
+
+	dsi->mode_flags = st7701->desc->flags;
+	dsi->format = st7701->desc->format;
+	dsi->lanes = st7701->desc->lanes;
+
 	mipi_dsi_set_drvdata(dsi, st7701);
 	st7701->dsi = dsi;
-	st7701->desc = desc;
 
 	ret = mipi_dsi_attach(dsi);
 	if (ret)
@@ -405,21 +647,115 @@ static int st7701_dsi_remove(struct mipi
 	return 0;
 }
 
-static const struct of_device_id st7701_of_match[] = {
+static const struct of_device_id st7701_dsi_of_match[] = {
 	{ .compatible = "techstar,ts8550b", .data = &ts8550b_desc },
 	{ }
 };
-MODULE_DEVICE_TABLE(of, st7701_of_match);
+MODULE_DEVICE_TABLE(of, st7701_dsi_of_match);
 
 static struct mipi_dsi_driver st7701_dsi_driver = {
 	.probe		= st7701_dsi_probe,
 	.remove		= st7701_dsi_remove,
 	.driver = {
 		.name		= "st7701",
-		.of_match_table	= st7701_of_match,
+		.of_match_table	= st7701_dsi_of_match,
 	},
 };
-module_mipi_dsi_driver(st7701_dsi_driver);
+
+/* SPI display  probe */
+static const struct of_device_id st7701_spi_of_match[] = {
+	{	.compatible = "txw,txw210001b0",
+		.data = &txw210001b0_desc,
+	}, {
+		.compatible = "pimoroni,hyperpixel2round",
+		.data = &hyperpixel2r_desc,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, st7701_spi_of_match);
+
+static int st7701_spi_probe(struct spi_device *spi)
+{
+	struct st7701 *st7701;
+	int ret;
+
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 9;
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to setup SPI: %d\n", ret);
+		return ret;
+	}
+
+	ret = st7701_probe(&spi->dev, &st7701);
+
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, st7701);
+	st7701->spi = spi;
+
+	return 0;
+}
+
+static int st7701_spi_remove(struct spi_device *spi)
+{
+	struct st7701 *ctx = spi_get_drvdata(spi);
+
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct spi_device_id st7701_spi_ids[] = {
+	{ "txw210001b0", 0 },
+	{ "hyperpixel2round", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(spi, st7701_spi_ids);
+
+static struct spi_driver st7701_spi_driver = {
+	.probe = st7701_spi_probe,
+	.remove = st7701_spi_remove,
+	.driver = {
+		.name = "st7701",
+		.of_match_table = st7701_spi_of_match,
+	},
+	.id_table = st7701_spi_ids,
+};
+
+static int __init panel_st7701_init(void)
+{
+	int err;
+
+	err = spi_register_driver(&st7701_spi_driver);
+	if (err < 0)
+		return err;
+
+	if (IS_ENABLED(CONFIG_DRM_MIPI_DSI)) {
+		err = mipi_dsi_driver_register(&st7701_dsi_driver);
+		if (err < 0)
+			goto err_did_spi_register;
+	}
+
+	return 0;
+
+err_did_spi_register:
+	spi_unregister_driver(&st7701_spi_driver);
+
+	return err;
+}
+module_init(panel_st7701_init);
+
+static void __exit panel_st7701_exit(void)
+{
+	if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
+		mipi_dsi_driver_unregister(&st7701_dsi_driver);
+
+	spi_unregister_driver(&st7701_spi_driver);
+}
+module_exit(panel_st7701_exit);
 
 MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
 MODULE_DESCRIPTION("Sitronix ST7701 LCD Panel Driver");