[PATCH v2 2/2] drm/tinydrm: add driver for ST7735R panels

[David Lechner]

This adds a new driver for Sitronix ST7735R display panels.

This has been tested using an Adafruit 1.8" TFT.

Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---

v2 changes:
* Change delay from 10ms to 20ms to avoid checkpatch warning
* Use mipi_dbi_pipe_enable()/mipi_dbi_pipe_disable() to reduce duplicated code
* Rebase on drm-misc-next (tinydrm_lastclose => drm_fb_helper_lastclose)
* Use mipi_dbi_debugfs_init
* Add mipi->read_commands = NULL; since this display is write-only


 MAINTAINERS                       |   6 ++
 drivers/gpu/drm/tinydrm/Kconfig   |  10 ++
 drivers/gpu/drm/tinydrm/Makefile  |   1 +
 drivers/gpu/drm/tinydrm/st7735r.c | 219 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 236 insertions(+)
 create mode 100644 drivers/gpu/drm/tinydrm/st7735r.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 0e49099..2ce17f5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4551,6 +4551,12 @@ S:	Maintained
 F:	drivers/gpu/drm/tinydrm/st7586.c
 F:	Documentation/devicetree/bindings/display/st7586.txt
 
+DRM DRIVER FOR SITRONIX ST7735R PANELS
+M:	David Lechner <david@xxxxxxxxxxxxxx>
+S:	Maintained
+F:	drivers/gpu/drm/tinydrm/st7735r.c
+F:	Documentation/devicetree/bindings/display/st7735r.txt
+
 DRM DRIVER FOR TDFX VIDEO CARDS
 S:	Orphan / Obsolete
 F:	drivers/gpu/drm/tdfx/
diff --git a/drivers/gpu/drm/tinydrm/Kconfig b/drivers/gpu/drm/tinydrm/Kconfig
index 90c5bd5..b0e567d 100644
--- a/drivers/gpu/drm/tinydrm/Kconfig
+++ b/drivers/gpu/drm/tinydrm/Kconfig
@@ -52,3 +52,13 @@ config TINYDRM_ST7586
 	  * LEGO MINDSTORMS EV3
 
 	  If M is selected the module will be called st7586.
+
+config TINYDRM_ST7735R
+	tristate "DRM support for Sitronix ST7735R display panels"
+	depends on DRM_TINYDRM && SPI
+	select TINYDRM_MIPI_DBI
+	help
+	  DRM driver Sitronix ST7735R with one of the following LCDs:
+	  * JD-T18003-T01 1.8" 128x160 TFT
+
+	  If M is selected the module will be called st7735r.
diff --git a/drivers/gpu/drm/tinydrm/Makefile b/drivers/gpu/drm/tinydrm/Makefile
index 8aeee53..49a1119 100644
--- a/drivers/gpu/drm/tinydrm/Makefile
+++ b/drivers/gpu/drm/tinydrm/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_TINYDRM_ILI9225)		+= ili9225.o
 obj-$(CONFIG_TINYDRM_MI0283QT)		+= mi0283qt.o
 obj-$(CONFIG_TINYDRM_REPAPER)		+= repaper.o
 obj-$(CONFIG_TINYDRM_ST7586)		+= st7586.o
+obj-$(CONFIG_TINYDRM_ST7735R)		+= st7735r.o
diff --git a/drivers/gpu/drm/tinydrm/st7735r.c b/drivers/gpu/drm/tinydrm/st7735r.c
new file mode 100644
index 0000000..0f5c295
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/st7735r.c
@@ -0,0 +1,219 @@
+/*
+ * DRM driver for Sitronix ST7735R panels
+ *
+ * Copyright 2017 David Lechner <david@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-buf.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/tinydrm/mipi-dbi.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+
+#define ST7735R_FRMCTR1		0xb1
+#define ST7735R_FRMCTR2		0xb2
+#define ST7735R_FRMCTR3		0xb3
+#define ST7735R_INVCTR		0xb4
+#define ST7735R_PWCTR1		0xc0
+#define ST7735R_PWCTR2		0xc1
+#define ST7735R_PWCTR3		0xc2
+#define ST7735R_PWCTR4		0xc3
+#define ST7735R_PWCTR5		0xc4
+#define ST7735R_VMCTR1		0xc5
+#define ST7735R_GAMCTRP1	0xe0
+#define ST7735R_GAMCTRN1	0xe1
+
+#define ST7735R_MY	BIT(7)
+#define ST7735R_MX	BIT(6)
+#define ST7735R_MV	BIT(5)
+
+static void st7735r_pipe_enable(struct drm_simple_display_pipe *pipe,
+				struct drm_crtc_state *crtc_state)
+{
+	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+	struct device *dev = tdev->drm->dev;
+	int ret;
+	u8 addr_mode;
+
+	DRM_DEBUG_KMS("\n");
+
+	mipi_dbi_hw_reset(mipi);
+
+	ret = mipi_dbi_command(mipi, MIPI_DCS_SOFT_RESET);
+	if (ret) {
+		DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
+		return;
+	}
+
+	msleep(150);
+
+	mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
+	msleep(500);
+
+	mipi_dbi_command(mipi, ST7735R_FRMCTR1, 0x01, 0x2c, 0x2d);
+	mipi_dbi_command(mipi, ST7735R_FRMCTR2, 0x01, 0x2c, 0x2d);
+	mipi_dbi_command(mipi, ST7735R_FRMCTR3, 0x01, 0x2c, 0x2d, 0x01, 0x2c,
+			 0x2d);
+	mipi_dbi_command(mipi, ST7735R_INVCTR, 0x07);
+	mipi_dbi_command(mipi, ST7735R_PWCTR1, 0xa2, 0x02, 0x84);
+	mipi_dbi_command(mipi, ST7735R_PWCTR2, 0xc5);
+	mipi_dbi_command(mipi, ST7735R_PWCTR3, 0x0a, 0x00);
+	mipi_dbi_command(mipi, ST7735R_PWCTR4, 0x8a, 0x2a);
+	mipi_dbi_command(mipi, ST7735R_PWCTR5, 0x8a, 0xee);
+	mipi_dbi_command(mipi, ST7735R_VMCTR1, 0x0e);
+	mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
+	switch (mipi->rotation) {
+	default:
+		addr_mode = ST7735R_MX | ST7735R_MY;
+		break;
+	case 90:
+		addr_mode = ST7735R_MX | ST7735R_MV;
+		break;
+	case 180:
+		addr_mode = 0;
+		break;
+	case 270:
+		addr_mode = ST7735R_MY | ST7735R_MV;
+		break;
+	}
+	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_PIXEL_FORMAT,
+			 MIPI_DCS_PIXEL_FMT_16BIT);
+	mipi_dbi_command(mipi, ST7735R_GAMCTRP1, 0x0f, 0x1a, 0x0f, 0x18, 0x2f,
+			 0x28, 0x20, 0x22, 0x1f, 0x1b, 0x23, 0x37, 0x00, 0x07,
+			 0x02, 0x10);
+	mipi_dbi_command(mipi, ST7735R_GAMCTRN1, 0x0f, 0x1b, 0x0f, 0x17, 0x33,
+			 0x2c, 0x29, 0x2e, 0x30, 0x30, 0x39, 0x3f, 0x00, 0x07,
+			 0x03, 0x10);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
+
+	msleep(100);
+
+	mipi_dbi_command(mipi, MIPI_DCS_ENTER_NORMAL_MODE);
+
+	msleep(20);
+
+	mipi_dbi_pipe_enable(pipe, crtc_state);
+}
+
+static const struct drm_simple_display_pipe_funcs st7735r_pipe_funcs = {
+	.enable		= st7735r_pipe_enable,
+	.disable	= mipi_dbi_pipe_disable,
+	.update		= tinydrm_display_pipe_update,
+	.prepare_fb	= tinydrm_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode st7735r_mode = {
+	TINYDRM_MODE(128, 160, 28, 35),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(st7735r_fops);
+
+static struct drm_driver st7735r_driver = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+				  DRIVER_ATOMIC,
+	.fops			= &st7735r_fops,
+	TINYDRM_GEM_DRIVER_OPS,
+	.lastclose		= drm_fb_helper_lastclose,
+	.debugfs_init		= mipi_dbi_debugfs_init,
+	.name			= "st7735r",
+	.desc			= "Sitronix ST7735R",
+	.date			= "20171128",
+	.major			= 1,
+	.minor			= 0,
+};
+
+static const struct of_device_id st7735r_of_match[] = {
+	{ .compatible = "sitronix,st7735r-jd-t18003-t01" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st7735r_of_match);
+
+static const struct spi_device_id st7735r_id[] = {
+	{ "st7735r-jd-t18003-t01", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, st7735r_id);
+
+static int st7735r_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct mipi_dbi *mipi;
+	struct gpio_desc *dc;
+	u32 rotation = 0;
+	int ret;
+
+	mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
+	if (!mipi)
+		return -ENOMEM;
+
+	mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(mipi->reset)) {
+		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
+		return PTR_ERR(mipi->reset);
+	}
+
+	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
+	if (IS_ERR(dc)) {
+		DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
+		return PTR_ERR(dc);
+	}
+
+	mipi->backlight = tinydrm_of_find_backlight(dev);
+	if (IS_ERR(mipi->backlight))
+		return PTR_ERR(mipi->backlight);
+
+	device_property_read_u32(dev, "rotation", &rotation);
+
+	ret = mipi_dbi_spi_init(spi, mipi, dc);
+	if (ret)
+		return ret;
+
+	/* Cannot read from Adafruit 1.8" display via SPI */
+	mipi->read_commands = NULL;
+
+	ret = mipi_dbi_init(&spi->dev, mipi, &st7735r_pipe_funcs,
+			    &st7735r_driver, &st7735r_mode, rotation);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, mipi);
+
+	return devm_tinydrm_register(&mipi->tinydrm);
+}
+
+static void st7735r_shutdown(struct spi_device *spi)
+{
+	struct mipi_dbi *mipi = spi_get_drvdata(spi);
+
+	tinydrm_shutdown(&mipi->tinydrm);
+}
+
+static struct spi_driver st7735r_spi_driver = {
+	.driver = {
+		.name = "st7735r",
+		.owner = THIS_MODULE,
+		.of_match_table = st7735r_of_match,
+	},
+	.id_table = st7735r_id,
+	.probe = st7735r_probe,
+	.shutdown = st7735r_shutdown,
+};
+module_spi_driver(st7735r_spi_driver);
+
+MODULE_DESCRIPTION("Sitronix ST7735R DRM driver");
+MODULE_AUTHOR("David Lechner <david@xxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
-- 
2.7.4