From f493a1250d55c4a61d94f631757186e8beef9d90 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Wed, 26 Jan 2022 16:02:31 +0000
Subject: [PATCH] drm/panel: Add panel driver for TDO Y17B based panels

The Top DisplayOptoelectronics (TDO) T17B driver chip is used
in the TL040HDS20CT panel (found in the Pimoroni HyperPixel4
Square display) and potentially other displays.
The driver chip supports SPI for  configuration and DPI
video data.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/panel/Kconfig          |  11 +
 drivers/gpu/drm/panel/Makefile         |   1 +
 drivers/gpu/drm/panel/panel-tdo-y17p.c | 279 +++++++++++++++++++++++++
 3 files changed, 291 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-tdo-y17p.c

--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -562,6 +562,17 @@ config DRM_PANEL_SONY_ACX565AKM
 	  Say Y here if you want to enable support for the Sony ACX565AKM
 	  800x600 3.5" panel (found on the Nokia N900).
 
+config DRM_PANEL_TPO_Y17P
+	tristate "TDO Y17P-based panels"
+	depends on OF && SPI
+	depends on DRM_KMS_HELPER
+	depends on DRM_KMS_CMA_HELPER
+	depends on BACKLIGHT_CLASS_DEVICE
+	select DRM_MIPI_DBI
+	help
+	  Say Y if you want to enable support for panels based on the
+	  TDO Y17P controller.
+
 config DRM_PANEL_TDO_TL070WSH30
 	tristate "TDO TL070WSH30 DSI panel"
 	depends on OF
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V)
 obj-$(CONFIG_DRM_PANEL_SONY_ACX424AKP) += panel-sony-acx424akp.o
 obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
 obj-$(CONFIG_DRM_PANEL_TDO_TL070WSH30) += panel-tdo-tl070wsh30.o
+obj-$(CONFIG_DRM_PANEL_TPO_Y17P) += panel-tdo-y17p.o
 obj-$(CONFIG_DRM_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-tdo-y17p.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TDO Y17P TFT LCD drm_panel driver.
+ *
+ * SPI configured DPI display controller
+ * Copyright (C) 2022 Raspberry Pi Ltd
+ *
+ * Derived from drivers/drm/gpu/panel/panel-sitronix-st7789v.c
+ * Copyright (C) 2017 Free Electrons
+ */
+
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+#include <linux/bitops.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 <video/mipi_display.h>
+#include <video/of_videomode.h>
+#include <video/videomode.h>
+
+struct tdo_y17p {
+	struct drm_panel panel;
+	struct spi_device *spi;
+	struct gpio_desc *reset;
+	struct regulator *power;
+	u32 bus_format;
+};
+
+static const u16 panel_init[] = {
+	0x0ff, 0x1ff, 0x198, 0x106, 0x104, 0x101, 0x008, 0x110,
+	0x021, 0x109, 0x030, 0x102, 0x031, 0x100, 0x040, 0x110,
+	0x041, 0x155, 0x042, 0x102, 0x043, 0x109, 0x044, 0x107,
+	0x050, 0x178, 0x051, 0x178, 0x052, 0x100, 0x053, 0x16d,
+	0x060, 0x107, 0x061, 0x100, 0x062, 0x108, 0x063, 0x100,
+	0x0a0, 0x100, 0x0a1, 0x107, 0x0a2, 0x10c, 0x0a3, 0x10b,
+	0x0a4, 0x103, 0x0a5, 0x107, 0x0a6, 0x106, 0x0a7, 0x104,
+	0x0a8, 0x108, 0x0a9, 0x10c, 0x0aa, 0x113, 0x0ab, 0x106,
+	0x0ac, 0x10d, 0x0ad, 0x119, 0x0ae, 0x110, 0x0af, 0x100,
+	0x0c0, 0x100, 0x0c1, 0x107, 0x0c2, 0x10c, 0x0c3, 0x10b,
+	0x0c4, 0x103, 0x0c5, 0x107, 0x0c6, 0x107, 0x0c7, 0x104,
+	0x0c8, 0x108, 0x0c9, 0x10c, 0x0ca, 0x113, 0x0cb, 0x106,
+	0x0cc, 0x10d, 0x0cd, 0x118, 0x0ce, 0x110, 0x0cf, 0x100,
+	0x0ff, 0x1ff, 0x198, 0x106, 0x104, 0x106, 0x000, 0x120,
+	0x001, 0x10a, 0x002, 0x100, 0x003, 0x100, 0x004, 0x101,
+	0x005, 0x101, 0x006, 0x198, 0x007, 0x106, 0x008, 0x101,
+	0x009, 0x180, 0x00a, 0x100, 0x00b, 0x100, 0x00c, 0x101,
+	0x00d, 0x101, 0x00e, 0x100, 0x00f, 0x100, 0x010, 0x1f0,
+	0x011, 0x1f4, 0x012, 0x101, 0x013, 0x100, 0x014, 0x100,
+	0x015, 0x1c0, 0x016, 0x108, 0x017, 0x100, 0x018, 0x100,
+	0x019, 0x100, 0x01a, 0x100, 0x01b, 0x100, 0x01c, 0x100,
+	0x01d, 0x100, 0x020, 0x101, 0x021, 0x123, 0x022, 0x145,
+	0x023, 0x167, 0x024, 0x101, 0x025, 0x123, 0x026, 0x145,
+	0x027, 0x167, 0x030, 0x111, 0x031, 0x111, 0x032, 0x100,
+	0x033, 0x1ee, 0x034, 0x1ff, 0x035, 0x1bb, 0x036, 0x1aa,
+	0x037, 0x1dd, 0x038, 0x1cc, 0x039, 0x166, 0x03a, 0x177,
+	0x03b, 0x122, 0x03c, 0x122, 0x03d, 0x122, 0x03e, 0x122,
+	0x03f, 0x122, 0x040, 0x122, 0x052, 0x110, 0x053, 0x110,
+	0x0ff, 0x1ff, 0x198, 0x106, 0x104, 0x107, 0x018, 0x11d,
+	0x017, 0x122, 0x002, 0x177, 0x026, 0x1b2, 0x0e1, 0x179,
+	0x0ff, 0x1ff, 0x198, 0x106, 0x104, 0x100, 0x03a, 0x160,
+	0x035, 0x100, 0x011, 0x100,
+};
+
+#define NUM_INIT_REGS ARRAY_SIZE(panel_init)
+
+static inline struct tdo_y17p *panel_to_tdo_y17p(struct drm_panel *panel)
+{
+	return container_of(panel, struct tdo_y17p, panel);
+}
+
+static int tdo_y17p_write_msg(struct tdo_y17p *ctx, const u16 *msg, unsigned int len)
+{
+	struct spi_transfer xfer = { };
+	struct spi_message spi;
+
+	spi_message_init(&spi);
+
+	xfer.tx_buf = msg;
+	xfer.bits_per_word = 9;
+	xfer.len = sizeof(u16) * len;
+
+	spi_message_add_tail(&xfer, &spi);
+	return spi_sync(ctx->spi, &spi);
+}
+
+static const struct drm_display_mode tdo_y17pe_720x720_mode = {
+	.clock = 36720,
+	.hdisplay = 720,
+	.hsync_start = 720 + 20,
+	.hsync_end = 720 + 20 + 20,
+	.htotal = 720 + 20 + 20 + 40,
+	.vdisplay = 720,
+	.vsync_start = 720 + 15,
+	.vsync_end = 720 + 15 + 15,
+	.vtotal = 720 + 15 + 15 + 15,
+	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC,
+};
+
+static int tdo_y17p_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct tdo_y17p *ctx = panel_to_tdo_y17p(panel);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, &tdo_y17pe_720x720_mode);
+	if (!mode) {
+		dev_err(panel->dev, "failed to add mode %ux%ux@%u\n",
+			tdo_y17pe_720x720_mode.hdisplay,
+			tdo_y17pe_720x720_mode.vdisplay,
+			drm_mode_vrefresh(&tdo_y17pe_720x720_mode));
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	drm_mode_probed_add(connector, mode);
+
+	connector->display_info.width_mm = 72;
+	connector->display_info.height_mm = 72;
+	drm_display_info_set_bus_formats(&connector->display_info,
+					 &ctx->bus_format, 1);
+	connector->display_info.bus_flags = 0;
+
+	return 1;
+}
+
+static int tdo_y17p_prepare(struct drm_panel *panel)
+{
+	struct tdo_y17p *ctx = panel_to_tdo_y17p(panel);
+	int ret;
+
+	ret = regulator_enable(ctx->power);
+	if (ret)
+		return ret;
+
+	ret = tdo_y17p_write_msg(ctx, panel_init, NUM_INIT_REGS);
+
+	msleep(120);
+
+	return ret;
+}
+
+static int tdo_y17p_enable(struct drm_panel *panel)
+{
+	struct tdo_y17p *ctx = panel_to_tdo_y17p(panel);
+	const u16 msg[] = { MIPI_DCS_SET_DISPLAY_ON };
+	int ret;
+
+	ret = tdo_y17p_write_msg(ctx, msg, ARRAY_SIZE(msg));
+
+	return ret;
+}
+
+static int tdo_y17p_disable(struct drm_panel *panel)
+{
+	struct tdo_y17p *ctx = panel_to_tdo_y17p(panel);
+	const u16 msg[] = { MIPI_DCS_SET_DISPLAY_OFF };
+	int ret;
+
+	ret = tdo_y17p_write_msg(ctx, msg, ARRAY_SIZE(msg));
+
+	return ret;
+}
+
+static int tdo_y17p_unprepare(struct drm_panel *panel)
+{
+	struct tdo_y17p *ctx = panel_to_tdo_y17p(panel);
+	const u16 msg[] = { MIPI_DCS_ENTER_SLEEP_MODE };
+	int ret;
+
+	ret = tdo_y17p_write_msg(ctx, msg, ARRAY_SIZE(msg));
+
+	return ret;
+}
+
+static const struct drm_panel_funcs tdo_y17p_drm_funcs = {
+	.disable	= tdo_y17p_disable,
+	.enable		= tdo_y17p_enable,
+	.get_modes	= tdo_y17p_get_modes,
+	.prepare	= tdo_y17p_prepare,
+	.unprepare	= tdo_y17p_unprepare,
+};
+
+static const struct of_device_id tdo_y17p_of_match[] = {
+	{	.compatible = "tdo,tl040hds20ct",
+		.data = (void *)MEDIA_BUS_FMT_BGR888_1X24,
+	}, {
+		.compatible = "pimoroni,hyperpixel4square",
+		.data = (void *)MEDIA_BUS_FMT_BGR666_1X24_CPADHI,
+	}, {
+		.compatible = "tdo,y17p",
+		.data = (void *)MEDIA_BUS_FMT_BGR888_1X24,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, tdo_y17p_of_match);
+
+static int tdo_y17p_probe(struct spi_device *spi)
+{
+	const struct of_device_id *id;
+	struct tdo_y17p *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(&spi->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	id = of_match_node(tdo_y17p_of_match, spi->dev.of_node);
+	if (!id)
+		return -ENODEV;
+
+	ctx->bus_format = (u32)id->data;
+
+	spi_set_drvdata(spi, ctx);
+	ctx->spi = spi;
+
+	drm_panel_init(&ctx->panel, &spi->dev, &tdo_y17p_drm_funcs,
+		       DRM_MODE_CONNECTOR_DPI);
+
+	ctx->power = devm_regulator_get(&spi->dev, "power");
+	if (IS_ERR(ctx->power))
+		return PTR_ERR(ctx->power);
+
+	ctx->reset = devm_gpiod_get_optional(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset)) {
+		dev_err(&spi->dev, "Couldn't get our reset line\n");
+		return PTR_ERR(ctx->reset);
+	}
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
+	drm_panel_add(&ctx->panel);
+
+	return 0;
+}
+
+static int tdo_y17p_remove(struct spi_device *spi)
+{
+	struct tdo_y17p *ctx = spi_get_drvdata(spi);
+
+	drm_panel_remove(&ctx->panel);
+
+	return 0;
+}
+
+static const struct spi_device_id tdo_y17p_ids[] = {
+	{ "tl040hds20ct", 0 },
+	{ "hyperpixel4square", 0 },
+	{ "y17p", 0 },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(spi, tdo_y17p_ids);
+
+static struct spi_driver tdo_y17p_driver = {
+	.probe = tdo_y17p_probe,
+	.remove = tdo_y17p_remove,
+	.driver = {
+		.name = "tdo_y17p",
+		.of_match_table = tdo_y17p_of_match,
+	},
+	.id_table = tdo_y17p_ids,
+};
+module_spi_driver(tdo_y17p_driver);
+
+MODULE_AUTHOR("Dave Stevenson <dave.stevenson@raspberrypi.com>");
+MODULE_DESCRIPTION("TDO Y17P LCD panel driver");
+MODULE_LICENSE("GPL v2");