Added st7796.c

drivers/gpu/drm/tiny/Kconfig

@@ -212,3 +212,15 @@ config TINYDRM_ST7735R
 	  * Okaya RH128128T 1.44" 128x128 TFT
 
 	  If M is selected the module will be called st7735r.
+config TINYDRM_ST7796S
+	tristate "DRM support for ST7796(S) LCD Controller"
+	depends on DRM && SPI
+	select DRM_KMS_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_MIPI_DBI
+	help
+	  Choose this option if you have a LCD display with a ST7796(S)
+	  controller. This driver provides the DRM support for the
+	  ST7796(S) controller through the Tiny DRM subsystem.
+
+	  If M is selected the module will be called st7796s.

drivers/gpu/drm/tiny/Makefile

@@ -16,3 +16,4 @@ obj-$(CONFIG_TINYDRM_MI0283QT)		+= mi0283qt.o
 obj-$(CONFIG_TINYDRM_REPAPER)		+= repaper.o
 obj-$(CONFIG_TINYDRM_ST7586)		+= st7586.o
 obj-$(CONFIG_TINYDRM_ST7735R)		+= st7735r.o
+obj-$(CONFIG_TINYDRM_ST7796)		+= st7796.o

drivers/gpu/drm/tiny/st7796.c

@@ -0,0 +1,328 @@
+/*
+ * DRM driver for Sitronix ST7796S panels
+ *
+ * Copyright 2016 Noralf Trønnes
+ *
+ * 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/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_modeset_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/tinydrm/mipi-dbi.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+#include <video/mipi_display.h>
+
+#define ST7796_NOP         0x00
+#define ST7796_SWRESET     0x01
+#define ST7796_RDDID       0x04
+#define ST7796_RDDST       0x09
+
+#define ST7796_SLPIN       0x10
+#define ST7796_SLPOUT      0x11
+#define ST7796_PTLON       0x12
+#define ST7796_NORON       0x13
+
+#define ST7796_RDMODE      0x0A
+#define ST7796_RDMADCTL    0x0B
+#define ST7796_RDPIXFMT    0x0C
+#define ST7796_RDIMGFMT    0x0A
+#define ST7796_RDSELFDIAG  0x0F
+
+#define ST7796_INVOFF      0x20
+#define ST7796_INVON       0x21
+
+#define ST7796_DISPOFF     0x28
+#define ST7796_DISPON      0x29
+
+#define ST7796_CASET       0x2A
+#define ST7796_PASET       0x2B
+#define ST7796_RAMWR       0x2C
+#define ST7796_RAMRD       0x2E
+
+#define ST7796_PTLAR       0x30
+#define ST7796_VSCRDEF     0x33
+#define ST7796_MADCTL      0x36
+#define ST7796_VSCRSADD    0x37
+#define ST7796_PIXFMT      0x3A
+
+#define ST7796_WRDISBV     0x51
+#define ST7796_RDDISBV     0x52
+#define ST7796_WRCTRLD     0x53
+
+#define ST7796_IFMODE      0xB0
+#define ST7796_FRMCTR1     0xB1
+#define ST7796_FRMCTR2     0xB2
+#define ST7796_FRMCTR3     0xB3
+#define ST7796_INVCTR      0xB4
+#define ST7796_BPCCTR      0xB5
+#define ST7796_DFUNCTR     0xB6
+#define ST7796_EMSET       0xB7
+
+#define ST7796_PWCTR1      0xC0
+#define ST7796_PWCTR2      0xC1
+#define ST7796_PWCTR3      0xC2
+
+#define ST7796_VMCTR1      0xC5
+#define ST7796_VMCOFF      0xC6
+
+#define ST7796_RDID4       0xD3
+
+#define ST7796_GMCTRP1     0xE0
+#define ST7796_GMCTRN1     0xE1
+#define ST7796_DOCACTL     0xE8
+
+#define ST7796_CSCONCTL    0xF0
+
+#define ST7796_MADCTL_MH	BIT(2)
+#define ST7796_MADCTL_BGR	BIT(3)
+#define ST7796_MADCTL_ML	BIT(4)
+#define ST7796_MADCTL_MV	BIT(5)
+#define ST7796_MADCTL_MX	BIT(6)
+#define ST7796_MADCTL_MY	BIT(7)
+
+static void st7796_enable(struct drm_simple_display_pipe *pipe,
+			    struct drm_crtc_state *crtc_state,
+			    struct drm_plane_state *plane_state)
+{
+	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+	u8 addr_mode;
+	int ret;
+
+	DRM_DEBUG_KMS("\n");
+
+	ret = mipi_dbi_poweron_conditional_reset(mipi);
+	if (ret < 0)
+		return;
+	if (ret == 1)
+		goto out_enable;
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
+	msleep(120);
+
+	/* Software reset */
+	mipi_dbi_command(mipi, ST7796_SWRESET);
+	msleep(120);
+
+	/* Sleep exit */
+	mipi_dbi_command(mipi, ST7796_SLPOUT);
+	msleep(120);
+
+	/* Command Set control */
+	mipi_dbi_command(mipi, ST7796_CSCONCTL, 0xC3);    //Enable extension command 2 partI
+
+	/* Command Set control */
+	mipi_dbi_command(mipi, ST7796_CSCONCTL, 0x96);    //Enable extension command 2 partII
+
+	/* Memory Data Access Control MX, MY, RGB mode */
+	mipi_dbi_command(mipi, ST7796_MADCTL, 0x48);    //X-Mirror, Top-Left to right-Buttom, RGB  
+
+	/* Interface Pixel Format */
+	mipi_dbi_command(mipi, ST7796_PIXFMT, 0x05);    //Control interface color format set to 16
+
+	mipi_dbi_command(mipi, ST7796_IFMODE, 0x80);
+	mipi_dbi_command(mipi, ST7796_DFUNCTR, 0x00, 0x02);
+	mipi_dbi_command(mipi, ST7796_BPCCTR, 0x02, 0x03, 0x00, 0x04);
+	mipi_dbi_command(mipi, ST7796_FRMCTR1, 0x80, 0x10);
+	mipi_dbi_command(mipi, ST7796_INVCTR, 0x00);
+	mipi_dbi_command(mipi, ST7796_EMSET, 0xC6);
+	mipi_dbi_command(mipi, ST7796_VMCTR1, 0x24);
+	mipi_dbi_command(mipi, 0xE4, 0x31);
+
+	/* Display Output Ctrl Adjust */
+	mipi_dbi_command(mipi, ST7796_DOCACTL, 0x40, 0x8A, 0x00, 0x00, 0x29, 0x19, 0xA5, 0x33);
+
+	/* Power control2 */
+	mipi_dbi_command(mipi, ST7796_PWCTR2, 0x06);    //VAP(GVDD)=3.85+( vcom+vcom offset), VAN(GVCL)=-3.85+( vcom+vcom offset)
+
+	/* Power control 3 */
+	mipi_dbi_command(mipi, ST7796_PWCTR3, 0xA7);    //Source driving current level=low, Gamma driving current level=High
+
+	/* VCOM Control */
+	mipi_dbi_command(mipi, ST7796_VMCTR1, 0x18);    //VCOM=0.9
+	msleep(120);
+
+	/* ST7796 Gamma Sequence */
+	/* Gamma"+" */
+	mipi_dbi_command(mipi, ST7796_GMCTRP1, 0xF0, 0x09, 0x0b, 0x06, 0x04, 0x15, 0x2F, 0x54, 0x42, 0x3C, 0x17, 0x14, 0x18, 0x1B); 
+	/* Gamma"-" */
+	mipi_dbi_command(mipi, ST7796_GMCTRN1, 0xE0, 0x09, 0x0B, 0x06, 0x04, 0x03, 0x2B, 0x43, 0x42, 0x3B, 0x16, 0x14, 0x17, 0x1B);
+	msleep(120);
+
+	/* Command Set control */
+	mipi_dbi_command(mipi, ST7796_CSCONCTL, 0x3C);    //Disable extension command 2 partI
+	mipi_dbi_command(mipi, ST7796_CSCONCTL, 0x69);    //Disable extension command 2 partII
+	msleep(100);
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
+	msleep(100);
+
+out_enable:
+	/* The PiTFT (ili9340) has a hardware reset circuit that
+	 * resets only on power-on and not on each reboot through
+	 * a gpio like the rpi-display does.
+	 * As a result, we need to always apply the rotation value
+	 * regardless of the display "on/off" state.
+	 */
+	switch (mipi->rotation) {
+	default:
+		addr_mode = ST7796_MADCTL_MX;
+		break;
+	case 90:
+		addr_mode = ST7796_MADCTL_MV;
+		break;
+	case 180:
+		addr_mode = ST7796_MADCTL_MY;
+		break;
+	case 270:
+		addr_mode = ST7796_MADCTL_MV | ST7796_MADCTL_MY |
+			    ST7796_MADCTL_MX;
+		break;
+	}
+	addr_mode |= ST7796_MADCTL_BGR;
+	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+	mipi_dbi_enable_flush(mipi, crtc_state, plane_state);
+}
+
+static const struct drm_simple_display_pipe_funcs st7796_pipe_funcs = {
+	.enable = st7796_enable,
+	.disable = mipi_dbi_pipe_disable,
+	.update = tinydrm_display_pipe_update,
+	.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode st7796_mode = {
+	TINYDRM_MODE(320, 480, 56, 84),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(st7796_fops);
+
+static struct drm_driver st7796_driver = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+				  DRIVER_ATOMIC,
+	.fops			= &st7796_fops,
+	TINYDRM_GEM_DRIVER_OPS,
+	.debugfs_init		= mipi_dbi_debugfs_init,
+	.name			= "st7796",
+	.desc			= "Sitronix ST7796",
+	.date			= "20200418",
+	.major			= 1,
+	.minor			= 0,
+};
+
+static const struct of_device_id st7796_of_match[] = {
+	{ .compatible = "sitronix,st7796" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st7796_of_match);
+
+static const struct spi_device_id st7796_id[] = {
+	{ "st7796", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, st7796_id);
+
+static int st7796_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_optional(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_optional(dev, "dc", GPIOD_OUT_LOW);
+	if (IS_ERR(dc)) {
+		DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
+		return PTR_ERR(dc);
+	}
+
+	mipi->regulator = devm_regulator_get(dev, "power");
+	if (IS_ERR(mipi->regulator))
+		return PTR_ERR(mipi->regulator);
+
+	mipi->backlight = devm_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;
+
+	ret = mipi_dbi_init(&spi->dev, mipi, &st7796_pipe_funcs,
+			    &st7796_driver, &st7796_mode, rotation);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, mipi);
+
+	return devm_tinydrm_register(&mipi->tinydrm);
+}
+
+static void st7796_shutdown(struct spi_device *spi)
+{
+	struct mipi_dbi *mipi = spi_get_drvdata(spi);
+
+	tinydrm_shutdown(&mipi->tinydrm);
+}
+
+static int __maybe_unused st7796_pm_suspend(struct device *dev)
+{
+	struct mipi_dbi *mipi = dev_get_drvdata(dev);
+
+	return drm_mode_config_helper_suspend(mipi->tinydrm.drm);
+}
+
+static int __maybe_unused st7796_pm_resume(struct device *dev)
+{
+	struct mipi_dbi *mipi = dev_get_drvdata(dev);
+
+	drm_mode_config_helper_resume(mipi->tinydrm.drm);
+
+	return 0;
+}
+
+static const struct dev_pm_ops st7796_pm_ops = {
+	//SET_SYSTEM_SLEEP_PM_OPS(st7796_pm_suspend, st7796_pm_resume)
+	SET_SYSTEM_SLEEP_PM_OPS(st7796_pm_resume, st7796_pm_suspend)
+};
+
+static struct spi_driver st7796_spi_driver = {
+	.driver = {
+		.name = "st7796",
+		.owner = THIS_MODULE,
+		.of_match_table = st7796_of_match,
+		.pm = &st7796_pm_ops,
+	},
+	.id_table = st7796_id,
+	.probe = st7796_probe,
+	.shutdown = st7796_shutdown,
+};
+module_spi_driver(st7796_spi_driver);
+
+MODULE_DESCRIPTION("Sitronix ST7796 DRM driver");
+MODULE_AUTHOR("BIRD TECHSTEP <[email protected]>");
+MODULE_LICENSE("GPL");