text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * DRM driver for Ilitek ILI9225 panels
   *
   * Copyright 2017 David Lechner <david@lechnology.com>
   *
   * Some code copied from mipi-dbi.c
   * Copyright 2016 Noralf Trønnes
   */
  
  #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_damage_helper.h>
  #include <drm/drm_drv.h>
  #include <drm/drm_fb_cma_helper.h>
  #include <drm/drm_fb_helper.h>
  #include <drm/drm_fourcc.h>
  #include <drm/drm_gem_cma_helper.h>
  #include <drm/drm_gem_framebuffer_helper.h>
  #include <drm/drm_managed.h>
  #include <drm/drm_mipi_dbi.h>
  #include <drm/drm_rect.h>
  
  #define ILI9225_DRIVER_READ_CODE	0x00
  #define ILI9225_DRIVER_OUTPUT_CONTROL	0x01
  #define ILI9225_LCD_AC_DRIVING_CONTROL	0x02
  #define ILI9225_ENTRY_MODE		0x03
  #define ILI9225_DISPLAY_CONTROL_1	0x07
  #define ILI9225_BLANK_PERIOD_CONTROL_1	0x08
  #define ILI9225_FRAME_CYCLE_CONTROL	0x0b
  #define ILI9225_INTERFACE_CONTROL	0x0c
  #define ILI9225_OSCILLATION_CONTROL	0x0f
  #define ILI9225_POWER_CONTROL_1		0x10
  #define ILI9225_POWER_CONTROL_2		0x11
  #define ILI9225_POWER_CONTROL_3		0x12
  #define ILI9225_POWER_CONTROL_4		0x13
  #define ILI9225_POWER_CONTROL_5		0x14
  #define ILI9225_VCI_RECYCLING		0x15
  #define ILI9225_RAM_ADDRESS_SET_1	0x20
  #define ILI9225_RAM_ADDRESS_SET_2	0x21
  #define ILI9225_WRITE_DATA_TO_GRAM	0x22
  #define ILI9225_SOFTWARE_RESET		0x28
  #define ILI9225_GATE_SCAN_CONTROL	0x30
  #define ILI9225_VERTICAL_SCROLL_1	0x31
  #define ILI9225_VERTICAL_SCROLL_2	0x32
  #define ILI9225_VERTICAL_SCROLL_3	0x33
  #define ILI9225_PARTIAL_DRIVING_POS_1	0x34
  #define ILI9225_PARTIAL_DRIVING_POS_2	0x35
  #define ILI9225_HORIZ_WINDOW_ADDR_1	0x36
  #define ILI9225_HORIZ_WINDOW_ADDR_2	0x37
  #define ILI9225_VERT_WINDOW_ADDR_1	0x38
  #define ILI9225_VERT_WINDOW_ADDR_2	0x39
  #define ILI9225_GAMMA_CONTROL_1		0x50
  #define ILI9225_GAMMA_CONTROL_2		0x51
  #define ILI9225_GAMMA_CONTROL_3		0x52
  #define ILI9225_GAMMA_CONTROL_4		0x53
  #define ILI9225_GAMMA_CONTROL_5		0x54
  #define ILI9225_GAMMA_CONTROL_6		0x55
  #define ILI9225_GAMMA_CONTROL_7		0x56
  #define ILI9225_GAMMA_CONTROL_8		0x57
  #define ILI9225_GAMMA_CONTROL_9		0x58
  #define ILI9225_GAMMA_CONTROL_10	0x59
  
  static inline int ili9225_command(struct mipi_dbi *dbi, u8 cmd, u16 data)
  {
  	u8 par[2] = { data >> 8, data & 0xff };
  
  	return mipi_dbi_command_buf(dbi, cmd, par, 2);
  }
  
  static void ili9225_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
  {
  	struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
  	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
  	unsigned int height = rect->y2 - rect->y1;
  	unsigned int width = rect->x2 - rect->x1;
  	struct mipi_dbi *dbi = &dbidev->dbi;
  	bool swap = dbi->swap_bytes;
  	u16 x_start, y_start;
  	u16 x1, x2, y1, y2;
  	int idx, ret = 0;
  	bool full;
  	void *tr;
  
  	if (!dbidev->enabled)
  		return;
  
  	if (!drm_dev_enter(fb->dev, &idx))
  		return;
  
  	full = width == fb->width && height == fb->height;
  
  	DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
  
  	if (!dbi->dc || !full || swap ||
  	    fb->format->format == DRM_FORMAT_XRGB8888) {
  		tr = dbidev->tx_buf;
  		ret = mipi_dbi_buf_copy(dbidev->tx_buf, fb, rect, swap);
  		if (ret)
  			goto err_msg;
  	} else {
  		tr = cma_obj->vaddr;
  	}
  
  	switch (dbidev->rotation) {
  	default:
  		x1 = rect->x1;
  		x2 = rect->x2 - 1;
  		y1 = rect->y1;
  		y2 = rect->y2 - 1;
  		x_start = x1;
  		y_start = y1;
  		break;
  	case 90:
  		x1 = rect->y1;
  		x2 = rect->y2 - 1;
  		y1 = fb->width - rect->x2;
  		y2 = fb->width - rect->x1 - 1;
  		x_start = x1;
  		y_start = y2;
  		break;
  	case 180:
  		x1 = fb->width - rect->x2;
  		x2 = fb->width - rect->x1 - 1;
  		y1 = fb->height - rect->y2;
  		y2 = fb->height - rect->y1 - 1;
  		x_start = x2;
  		y_start = y2;
  		break;
  	case 270:
  		x1 = fb->height - rect->y2;
  		x2 = fb->height - rect->y1 - 1;
  		y1 = rect->x1;
  		y2 = rect->x2 - 1;
  		x_start = x2;
  		y_start = y1;
  		break;
  	}
  
  	ili9225_command(dbi, ILI9225_HORIZ_WINDOW_ADDR_1, x2);
  	ili9225_command(dbi, ILI9225_HORIZ_WINDOW_ADDR_2, x1);
  	ili9225_command(dbi, ILI9225_VERT_WINDOW_ADDR_1, y2);
  	ili9225_command(dbi, ILI9225_VERT_WINDOW_ADDR_2, y1);
  
  	ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_1, x_start);
  	ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_2, y_start);
  
  	ret = mipi_dbi_command_buf(dbi, ILI9225_WRITE_DATA_TO_GRAM, tr,
  				   width * height * 2);
  err_msg:
  	if (ret)
  		dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
  
  	drm_dev_exit(idx);
  }
  
  static void ili9225_pipe_update(struct drm_simple_display_pipe *pipe,
  				struct drm_plane_state *old_state)
  {
  	struct drm_plane_state *state = pipe->plane.state;
  	struct drm_rect rect;
  
  	if (drm_atomic_helper_damage_merged(old_state, state, &rect))
  		ili9225_fb_dirty(state->fb, &rect);
  }
  
  static void ili9225_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 drm_framebuffer *fb = plane_state->fb;
  	struct device *dev = pipe->crtc.dev->dev;
  	struct mipi_dbi *dbi = &dbidev->dbi;
  	struct drm_rect rect = {
  		.x1 = 0,
  		.x2 = fb->width,
  		.y1 = 0,
  		.y2 = fb->height,
  	};
  	int ret, idx;
  	u8 am_id;
  
  	if (!drm_dev_enter(pipe->crtc.dev, &idx))
  		return;
  
  	DRM_DEBUG_KMS("\n");
  
  	mipi_dbi_hw_reset(dbi);
  
  	/*
  	 * There don't seem to be two example init sequences that match, so
  	 * using the one from the popular Arduino library for this display.
  	 * https://github.com/Nkawu/TFT_22_ILI9225/blob/master/src/TFT_22_ILI9225.cpp
  	 */
  
  	ret = ili9225_command(dbi, ILI9225_POWER_CONTROL_1, 0x0000);
  	if (ret) {
  		DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
  		goto out_exit;
  	}
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x0000);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_3, 0x0000);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_4, 0x0000);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_5, 0x0000);
  
  	msleep(40);
  
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x0018);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_3, 0x6121);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_4, 0x006f);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_5, 0x495f);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_1, 0x0800);
  
  	msleep(10);
  
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x103b);
  
  	msleep(50);
  
  	switch (dbidev->rotation) {
  	default:
  		am_id = 0x30;
  		break;
  	case 90:
  		am_id = 0x18;
  		break;
  	case 180:
  		am_id = 0x00;
  		break;
  	case 270:
  		am_id = 0x28;
  		break;
  	}
  	ili9225_command(dbi, ILI9225_DRIVER_OUTPUT_CONTROL, 0x011c);
  	ili9225_command(dbi, ILI9225_LCD_AC_DRIVING_CONTROL, 0x0100);
  	ili9225_command(dbi, ILI9225_ENTRY_MODE, 0x1000 | am_id);
  	ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x0000);
  	ili9225_command(dbi, ILI9225_BLANK_PERIOD_CONTROL_1, 0x0808);
  	ili9225_command(dbi, ILI9225_FRAME_CYCLE_CONTROL, 0x1100);
  	ili9225_command(dbi, ILI9225_INTERFACE_CONTROL, 0x0000);
  	ili9225_command(dbi, ILI9225_OSCILLATION_CONTROL, 0x0d01);
  	ili9225_command(dbi, ILI9225_VCI_RECYCLING, 0x0020);
  	ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_1, 0x0000);
  	ili9225_command(dbi, ILI9225_RAM_ADDRESS_SET_2, 0x0000);
  
  	ili9225_command(dbi, ILI9225_GATE_SCAN_CONTROL, 0x0000);
  	ili9225_command(dbi, ILI9225_VERTICAL_SCROLL_1, 0x00db);
  	ili9225_command(dbi, ILI9225_VERTICAL_SCROLL_2, 0x0000);
  	ili9225_command(dbi, ILI9225_VERTICAL_SCROLL_3, 0x0000);
  	ili9225_command(dbi, ILI9225_PARTIAL_DRIVING_POS_1, 0x00db);
  	ili9225_command(dbi, ILI9225_PARTIAL_DRIVING_POS_2, 0x0000);
  
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_1, 0x0000);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_2, 0x0808);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_3, 0x080a);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_4, 0x000a);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_5, 0x0a08);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_6, 0x0808);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_7, 0x0000);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_8, 0x0a00);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_9, 0x0710);
  	ili9225_command(dbi, ILI9225_GAMMA_CONTROL_10, 0x0710);
  
  	ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x0012);
  
  	msleep(50);
  
  	ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x1017);
  
  	dbidev->enabled = true;
  	ili9225_fb_dirty(fb, &rect);
  out_exit:
  	drm_dev_exit(idx);
  }
  
  static void ili9225_pipe_disable(struct drm_simple_display_pipe *pipe)
  {
  	struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
  	struct mipi_dbi *dbi = &dbidev->dbi;
  
  	DRM_DEBUG_KMS("\n");
  
  	/*
  	 * This callback is not protected by drm_dev_enter/exit since we want to
  	 * turn off the display on regular driver unload. It's highly unlikely
  	 * that the underlying SPI controller is gone should this be called after
  	 * unplug.
  	 */
  
  	if (!dbidev->enabled)
  		return;
  
  	ili9225_command(dbi, ILI9225_DISPLAY_CONTROL_1, 0x0000);
  	msleep(50);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_2, 0x0007);
  	msleep(50);
  	ili9225_command(dbi, ILI9225_POWER_CONTROL_1, 0x0a02);
  
  	dbidev->enabled = false;
  }
  
  static int ili9225_dbi_command(struct mipi_dbi *dbi, u8 *cmd, u8 *par,
  			       size_t num)
  {
  	struct spi_device *spi = dbi->spi;
  	unsigned int bpw = 8;
  	u32 speed_hz;
  	int ret;
  
  	gpiod_set_value_cansleep(dbi->dc, 0);
  	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1);
  	ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1);
  	if (ret || !num)
  		return ret;
  
  	if (*cmd == ILI9225_WRITE_DATA_TO_GRAM && !dbi->swap_bytes)
  		bpw = 16;
  
  	gpiod_set_value_cansleep(dbi->dc, 1);
  	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
  
  	return mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
  }
  
  static const struct drm_simple_display_pipe_funcs ili9225_pipe_funcs = {
  	.enable		= ili9225_pipe_enable,
  	.disable	= ili9225_pipe_disable,
  	.update		= ili9225_pipe_update,
  	.prepare_fb	= drm_gem_fb_simple_display_pipe_prepare_fb,
  };
  
  static const struct drm_display_mode ili9225_mode = {
  	DRM_SIMPLE_MODE(176, 220, 35, 44),
  };
  
  DEFINE_DRM_GEM_CMA_FOPS(ili9225_fops);
  
  static struct drm_driver ili9225_driver = {
  	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
  	.fops			= &ili9225_fops,
  	DRM_GEM_CMA_VMAP_DRIVER_OPS,
  	.name			= "ili9225",
  	.desc			= "Ilitek ILI9225",
  	.date			= "20171106",
  	.major			= 1,
  	.minor			= 0,
  };
  
  static const struct of_device_id ili9225_of_match[] = {
  	{ .compatible = "vot,v220hf01a-t" },
  	{},
  };
  MODULE_DEVICE_TABLE(of, ili9225_of_match);
  
  static const struct spi_device_id ili9225_id[] = {
  	{ "v220hf01a-t", 0 },
  	{ },
  };
  MODULE_DEVICE_TABLE(spi, ili9225_id);
  
  static int ili9225_probe(struct spi_device *spi)
  {
  	struct device *dev = &spi->dev;
  	struct mipi_dbi_dev *dbidev;
  	struct drm_device *drm;
  	struct mipi_dbi *dbi;
  	struct gpio_desc *rs;
  	u32 rotation = 0;
  	int ret;
  
  	dbidev = devm_drm_dev_alloc(dev, &ili9225_driver,
  				    struct mipi_dbi_dev, drm);
  	if (IS_ERR(dbidev))
  		return PTR_ERR(dbidev);
  
  	dbi = &dbidev->dbi;
  	drm = &dbidev->drm;
  
  	dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
  	if (IS_ERR(dbi->reset)) {
  		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
  		return PTR_ERR(dbi->reset);
  	}
  
  	rs = devm_gpiod_get(dev, "rs", GPIOD_OUT_LOW);
  	if (IS_ERR(rs)) {
  		DRM_DEV_ERROR(dev, "Failed to get gpio 'rs'\n");
  		return PTR_ERR(rs);
  	}
  
  	device_property_read_u32(dev, "rotation", &rotation);
  
  	ret = mipi_dbi_spi_init(spi, dbi, rs);
  	if (ret)
  		return ret;
  
  	/* override the command function set in  mipi_dbi_spi_init() */
  	dbi->command = ili9225_dbi_command;
  
  	ret = mipi_dbi_dev_init(dbidev, &ili9225_pipe_funcs, &ili9225_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_generic_setup(drm, 0);
  
  	return 0;
  }
  
  static int ili9225_remove(struct spi_device *spi)
  {
  	struct drm_device *drm = spi_get_drvdata(spi);
  
  	drm_dev_unplug(drm);
  	drm_atomic_helper_shutdown(drm);
  
  	return 0;
  }
  
  static void ili9225_shutdown(struct spi_device *spi)
  {
  	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
  }
  
  static struct spi_driver ili9225_spi_driver = {
  	.driver = {
  		.name = "ili9225",
  		.owner = THIS_MODULE,
  		.of_match_table = ili9225_of_match,
  	},
  	.id_table = ili9225_id,
  	.probe = ili9225_probe,
  	.remove = ili9225_remove,
  	.shutdown = ili9225_shutdown,
  };
  module_spi_driver(ili9225_spi_driver);
  
  MODULE_DESCRIPTION("Ilitek ILI9225 DRM driver");
  MODULE_AUTHOR("David Lechner <david@lechnology.com>");
  MODULE_LICENSE("GPL");
  