msm8916-openwrt/driver.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * DRM driver for Sitronix ST7735S display panels
 *
 * Based on st7735r driver by David Lechner <david@lechnology.com>
 * Android DTS sequence implementation
 */

#include <linux/backlight.h>
#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_atomic_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_mipi_dbi.h>

#define ST7735S_FRMCTR1		0xb1
#define ST7735S_FRMCTR2		0xb2
#define ST7735S_FRMCTR3		0xb3
#define ST7735S_INVCTR		0xb4
#define ST7735S_PWCTR1		0xc0
#define ST7735S_PWCTR2		0xc1
#define ST7735S_PWCTR3		0xc2
#define ST7735S_PWCTR4		0xc3
#define ST7735S_PWCTR5		0xc4
#define ST7735S_VMCTR1		0xc5
#define ST7735S_GAMCTRP1	0xe0
#define ST7735S_GAMCTRN1	0xe1

#define ST7735S_MY	BIT(7)
#define ST7735S_MX	BIT(6)
#define ST7735S_MV	BIT(5)
#define ST7735S_RGB	BIT(3)

struct st7735s_cfg {
	const struct drm_display_mode mode;
	unsigned int left_offset;
	unsigned int top_offset;
	unsigned int write_only:1;
	unsigned int rgb:1;
};

struct st7735s_priv {
	struct mipi_dbi_dev dbidev;
	const struct st7735s_cfg *cfg;
};

/*
 * Android DTS initialization sequence from MSM8916
 * DO NOT modify order or add extra commands
 */
static void st7735s_pipe_enable(struct drm_simple_display_pipe *pipe,
				struct drm_crtc_state *crtc_state,
				struct drm_plane_state *plane_state)
{
	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
	struct st7735s_priv *priv = container_of(dbidev, struct st7735s_priv,
						 dbidev);
	struct mipi_dbi *dbi = &dbidev->dbi;
	int ret, idx;

	if (!drm_dev_enter(pipe->crtc.dev, &idx))
		return;

	pr_info("st7735s: === BEGIN ANDROID SEQUENCE ===\n");

	ret = mipi_dbi_poweron_reset(dbidev);
	if (ret) {
		pr_err("st7735s: poweron_reset failed: %d\n", ret);
		goto out_exit;
	}

	/* 1. EXIT_SLEEP_MODE (0x11) - delay 150ms (0x96) */
	pr_info("st7735s: [1/19] EXIT_SLEEP_MODE (0x11)\n");
	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
	msleep(150);

	/* 2. SET_ADDRESS_MODE (0x36) - 0x00 */
	pr_info("st7735s: [2/19] SET_ADDRESS_MODE (0x36) = 0x00\n");
	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x00);

	/* 3. SET_COLUMN_ADDRESS (0x2a) - 0,0,0,131 */
	pr_info("st7735s: [3/19] SET_COLUMN_ADDRESS (0x2a) = 0,0,0,131\n");
	mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
			 0x00, 0x00, 0x00, 0x83);

	/* 4. SET_PAGE_ADDRESS (0x2b) - 0,0,0,131 */
	pr_info("st7735s: [4/19] SET_PAGE_ADDRESS (0x2b) = 0,0,0,131\n");
	mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
			 0x00, 0x00, 0x00, 0x83);

	/* 5. SET_PIXEL_FORMAT (0x3a) - 0x05 (16-bit RGB565) */
	pr_info("st7735s: [5/19] SET_PIXEL_FORMAT (0x3a) = 0x05\n");
	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x05);

	/* 6. FRMCTR1 (0xb1) - 0x05,0x3c,0x3c */
	pr_info("st7735s: [6/19] FRMCTR1 (0xb1)\n");
	mipi_dbi_command(dbi, ST7735S_FRMCTR1, 0x05, 0x3c, 0x3c);

	/* 7. FRMCTR2 (0xb2) - 0x05,0x3c,0x3c */
	pr_info("st7735s: [7/19] FRMCTR2 (0xb2)\n");
	mipi_dbi_command(dbi, ST7735S_FRMCTR2, 0x05, 0x3c, 0x3c);

	/* 8. FRMCTR3 (0xb3) - 0x05,0x3c,0x3c,0x05,0x3c,0x3c */
	pr_info("st7735s: [8/19] FRMCTR3 (0xb3)\n");
	mipi_dbi_command(dbi, ST7735S_FRMCTR3, 0x05, 0x3c, 0x3c,
			 0x05, 0x3c, 0x3c);

	/* 9. INVCTR (0xb4) - 0x03 */
	pr_info("st7735s: [9/19] INVCTR (0xb4) = 0x03\n");
	mipi_dbi_command(dbi, ST7735S_INVCTR, 0x03);

	/* 10. PWCTR1 (0xc0) - 0x0e,0x0e,0x04 */
	pr_info("st7735s: [10/19] PWCTR1 (0xc0)\n");
	mipi_dbi_command(dbi, ST7735S_PWCTR1, 0x0e, 0x0e, 0x04);

	/* 11. PWCTR2 (0xc1) - 0xc0 */
	pr_info("st7735s: [11/19] PWCTR2 (0xc1) = 0xc0\n");
	mipi_dbi_command(dbi, ST7735S_PWCTR2, 0xc0);

	/* 12. PWCTR3 (0xc2) - 0x0d,0x00 */
	pr_info("st7735s: [12/19] PWCTR3 (0xc2)\n");
	mipi_dbi_command(dbi, ST7735S_PWCTR3, 0x0d, 0x00);

	/* 13. PWCTR4 (0xc3) - 0x8d,0x2a */
	pr_info("st7735s: [13/19] PWCTR4 (0xc3)\n");
	mipi_dbi_command(dbi, ST7735S_PWCTR4, 0x8d, 0x2a);

	/* 14. PWCTR5 (0xc4) - 0x8d,0xee */
	pr_info("st7735s: [14/19] PWCTR5 (0xc4)\n");
	mipi_dbi_command(dbi, ST7735S_PWCTR5, 0x8d, 0xee);

	/* 15. VMCTR1 (0xc5) - 0x0c */
	pr_info("st7735s: [15/19] VMCTR1 (0xc5) = 0x0c\n");
	mipi_dbi_command(dbi, ST7735S_VMCTR1, 0x0c);

	/* 16. GAMCTRP1 (0xe0) - Positive Gamma */
	pr_info("st7735s: [16/19] GAMCTRP1 (0xe0)\n");
	mipi_dbi_command(dbi, ST7735S_GAMCTRP1,
			 0x0c, 0x1c, 0x0f, 0x18, 0x36, 0x2f, 0x27, 0x2a,
			 0x27, 0x25, 0x2d, 0x3c, 0x00, 0x05, 0x03, 0x10);

	/* 17. GAMCTRN1 (0xe1) - Negative Gamma */
	pr_info("st7735s: [17/19] GAMCTRN1 (0xe1)\n");
	mipi_dbi_command(dbi, ST7735S_GAMCTRN1,
			 0x0c, 0x1a, 0x09, 0x09, 0x26, 0x22, 0x1e, 0x25,
			 0x25, 0x25, 0x2e, 0x3b, 0x00, 0x05, 0x03, 0x10);

	/* 18. ENTER_INVERT_MODE (0x21) */
	pr_info("st7735s: [18/19] ENTER_INVERT_MODE (0x21)\n");
	mipi_dbi_command(dbi, MIPI_DCS_ENTER_INVERT_MODE);

	/* 19. SET_DISPLAY_ON (0x29) - delay 120ms (0x78) */
	pr_info("st7735s: [19/19] SET_DISPLAY_ON (0x29)\n");
	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
	msleep(120);

	pr_info("st7735s: === SEQUENCE COMPLETE, calling flush ===\n");
	mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
	pr_info("st7735s: === FLUSH COMPLETE ===\n");

out_exit:
	drm_dev_exit(idx);
}

static const struct drm_simple_display_pipe_funcs st7735s_pipe_funcs = {
	DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(st7735s_pipe_enable),
};

static const struct st7735s_cfg st7735s_128x128_cfg = {
	.mode		= { DRM_SIMPLE_MODE(128, 128, 22, 22) },
	.left_offset	= 2,
	.top_offset	= 1,
	.write_only	= false,
	.rgb		= false,
};

/* ... resto del driver igual ... */


DEFINE_DRM_GEM_DMA_FOPS(st7735s_fops);

static const struct drm_driver st7735s_driver = {
	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
	.fops			= &st7735s_fops,
	DRM_GEM_DMA_DRIVER_OPS_VMAP,
	.debugfs_init		= mipi_dbi_debugfs_init,
	.name			= "st7735s",
	.desc			= "Sitronix ST7735S",
	.date			= "20251013",
	.major			= 1,
	.minor			= 0,
};

static const struct of_device_id st7735s_of_match[] = {
	{ .compatible = "sitronix,st7735s", .data = &st7735s_128x128_cfg },
	{ },
};
MODULE_DEVICE_TABLE(of, st7735s_of_match);

static const struct spi_device_id st7735s_id[] = {
	{ "st7735s", (uintptr_t)&st7735s_128x128_cfg },
	{ },
};
MODULE_DEVICE_TABLE(spi, st7735s_id);

static int st7735s_probe(struct spi_device *spi)
{
	struct device *dev = &spi->dev;
	const struct st7735s_cfg *cfg;
	struct mipi_dbi_dev *dbidev;
	struct st7735s_priv *priv;
	struct drm_device *drm;
	struct mipi_dbi *dbi;
	struct gpio_desc *dc;
	u32 rotation = 0;
	int ret;

	cfg = device_get_match_data(&spi->dev);
	if (!cfg)
		cfg = (void *)spi_get_device_id(spi)->driver_data;

	priv = devm_drm_dev_alloc(dev, &st7735s_driver,
				  struct st7735s_priv, dbidev.drm);
	if (IS_ERR(priv))
		return PTR_ERR(priv);

	dbidev = &priv->dbidev;
	priv->cfg = cfg;

	dbi = &dbidev->dbi;
	drm = &dbidev->drm;

	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(dbi->reset))
		return dev_err_probe(dev, PTR_ERR(dbi->reset),
				     "Failed to get GPIO 'reset'\n");

	dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
	if (IS_ERR(dc))
		return dev_err_probe(dev, PTR_ERR(dc),
				     "Failed to get GPIO 'dc'\n");

	dbidev->backlight = devm_of_find_backlight(dev);
	if (IS_ERR(dbidev->backlight))
		return PTR_ERR(dbidev->backlight);

	device_property_read_u32(dev, "rotation", &rotation);

	ret = mipi_dbi_spi_init(spi, dbi, dc);
	if (ret)
		return ret;

	if (cfg->write_only)
		dbi->read_commands = NULL;

	dbidev->left_offset = cfg->left_offset;
	dbidev->top_offset = cfg->top_offset;

	ret = mipi_dbi_dev_init(dbidev, &st7735s_pipe_funcs, &cfg->mode,
				rotation);
	if (ret)
		return ret;

	drm_mode_config_reset(drm);

	ret = drm_dev_register(drm, 0);
	if (ret)
		return ret;

	spi_set_drvdata(spi, drm);

	drm_fbdev_dma_setup(drm, 16);

	return 0;
}

static void st7735s_remove(struct spi_device *spi)
{
	struct drm_device *drm = spi_get_drvdata(spi);

	drm_dev_unplug(drm);
	drm_atomic_helper_shutdown(drm);
}

static void st7735s_shutdown(struct spi_device *spi)
{
	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
}

static struct spi_driver st7735s_spi_driver = {
	.driver = {
		.name = "st7735s",
		.of_match_table = st7735s_of_match,
	},
	.id_table = st7735s_id,
	.probe = st7735s_probe,
	.remove = st7735s_remove,
	.shutdown = st7735s_shutdown,
};
module_spi_driver(st7735s_spi_driver);

MODULE_DESCRIPTION("Sitronix ST7735S DRM driver");
MODULE_AUTHOR("Based on st7735r by David Lechner");
MODULE_LICENSE("GPL");