drivers/gpu/drm/tiny/ili9486.c - linux - Git at Google


            
            // SPDX-License-Identifier: GPL-2.0+

            
            /*

            
             * DRM driver for Ilitek ILI9486 panels

            
             *

            
             * Copyright 2020 Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>

            
             */


            #include <linux/backlight.h>

            
            #include <linux/delay.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/clients/drm_client_setup.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>

            
            #include <drm/drm_modeset_helper.h>

            
            #include <drm/drm_print.h>


            #define ILI9486_ITFCTR1         0xb0

            
            #define ILI9486_PWCTRL1         0xc2

            
            #define ILI9486_VMCTRL1         0xc5

            
            #define ILI9486_PGAMCTRL        0xe0

            
            #define ILI9486_NGAMCTRL        0xe1

            
            #define ILI9486_DGAMCTRL        0xe2

            
            #define ILI9486_MADCTL_BGR      BIT(3)

            
            #define ILI9486_MADCTL_MV       BIT(5)

            
            #define ILI9486_MADCTL_MX       BIT(6)

            
            #define ILI9486_MADCTL_MY       BIT(7)


            struct ili9486_device {

            
            	struct mipi_dbi_dev dbidev;


            	struct drm_plane plane;

            
            	struct drm_crtc crtc;

            
            	struct drm_encoder encoder;

            
            	struct drm_connector connector;

            
            };


            static struct ili9486_device *to_ili9486_device(struct drm_device *dev)

            
            {

            
            	return container_of(drm_to_mipi_dbi_dev(dev), struct ili9486_device, dbidev);

            
            }


            /*

            
             * The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter

            
             * in front of the  display controller. This means that 8-bit values have to be

            
             * transferred as 16-bit.

            
             */

            
            static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd, u8 *par,

            
            			     size_t num)

            
            {

            
            	struct spi_device *spi = mipi->spi;

            
            	unsigned int bpw = 8;

            
            	void *data = par;

            
            	u32 speed_hz;

            
            	int i, ret;

            
            	__be16 *buf;


            	buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);

            
            	if (!buf)

            
            		return -ENOMEM;


            	/*

            
            	 * The displays are Raspberry Pi HATs and connected to the 8-bit only

            
            	 * SPI controller, so 16-bit command and parameters need byte swapping

            
            	 * before being transferred as 8-bit on the big endian SPI bus.

            
            	 */

            
            	buf[0] = cpu_to_be16(*cmd);

            
            	spi_bus_lock(spi->controller);

            
            	gpiod_set_value_cansleep(mipi->dc, 0);

            
            	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);

            
            	ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);

            
            	spi_bus_unlock(spi->controller);

            
            	if (ret || !num)

            
            		goto free;


            	/* 8-bit configuration data, not 16-bit pixel data */

            
            	if (num <= 32) {

            
            		for (i = 0; i < num; i++)

            
            			buf[i] = cpu_to_be16(par[i]);

            
            		num *= 2;

            
            		data = buf;

            
            	}


            	/*

            
            	 * Check whether pixel data bytes needs to be swapped or not

            
            	 */

            
            	if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)

            
            		bpw = 16;


            	spi_bus_lock(spi->controller);

            
            	gpiod_set_value_cansleep(mipi->dc, 1);

            
            	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);

            
            	ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);

            
            	spi_bus_unlock(spi->controller);

            
             free:

            
            	kfree(buf);


            	return ret;

            
            }


            static const u32 ili9486_plane_formats[] = {

            
            	DRM_MIPI_DBI_PLANE_FORMATS,

            
            };


            static const u64 ili9486_plane_format_modifiers[] = {

            
            	DRM_MIPI_DBI_PLANE_FORMAT_MODIFIERS,

            
            };


            static const struct drm_plane_helper_funcs ili9486_plane_helper_funcs = {

            
            	DRM_MIPI_DBI_PLANE_HELPER_FUNCS,

            
            };


            static const struct drm_plane_funcs ili9486_plane_funcs = {

            
            	DRM_MIPI_DBI_PLANE_FUNCS,

            
            	.destroy = drm_plane_cleanup,

            
            };


            static void ili9486_crtc_helper_atomic_enable(struct drm_crtc *crtc,

            
            					      struct drm_atomic_commit *state)

            
            {

            
            	struct drm_device *drm = crtc->dev;

            
            	struct ili9486_device *ili9486 = to_ili9486_device(drm);

            
            	struct mipi_dbi_dev *dbidev = &ili9486->dbidev;

            
            	struct mipi_dbi *dbi = &dbidev->dbi;

            
            	u8 addr_mode;

            
            	int ret, idx;


            	if (!drm_dev_enter(drm, &idx))

            
            		return;


            	DRM_DEBUG_KMS("\n");


            	ret = mipi_dbi_poweron_conditional_reset(dbidev);

            
            	if (ret < 0)

            
            		goto out_exit;

            
            	if (ret == 1)

            
            		goto out_enable;


            	mipi_dbi_command(dbi, ILI9486_ITFCTR1);

            
            	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);

            
            	msleep(250);


            	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);


            	mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);


            	mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);


            	mipi_dbi_command(dbi, ILI9486_PGAMCTRL,

            
            			 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,

            
            			 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);

            
            	mipi_dbi_command(dbi, ILI9486_NGAMCTRL,

            
            			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,

            
            			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);

            
            	mipi_dbi_command(dbi, ILI9486_DGAMCTRL,

            
            			 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,

            
            			 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);


            	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);

            
            	msleep(100);


             out_enable:

            
            	switch (dbidev->rotation) {

            
            	case 90:

            
            		addr_mode = ILI9486_MADCTL_MY;

            
            		break;

            
            	case 180:

            
            		addr_mode = ILI9486_MADCTL_MV;

            
            		break;

            
            	case 270:

            
            		addr_mode = ILI9486_MADCTL_MX;

            
            		break;

            
            	default:

            
            		addr_mode = ILI9486_MADCTL_MV | ILI9486_MADCTL_MY |

            
            			ILI9486_MADCTL_MX;

            
            		break;

            
            	}

            
            	addr_mode |= ILI9486_MADCTL_BGR;

            
            	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);


            	backlight_enable(dbidev->backlight);

            
             out_exit:

            
            	drm_dev_exit(idx);

            
            }


            static const struct drm_crtc_helper_funcs ili9486_crtc_helper_funcs = {

            
            	DRM_MIPI_DBI_CRTC_HELPER_FUNCS,

            
            	.atomic_enable = ili9486_crtc_helper_atomic_enable,

            
            };


            static const struct drm_crtc_funcs ili9486_crtc_funcs = {

            
            	DRM_MIPI_DBI_CRTC_FUNCS,

            
            	.destroy = drm_crtc_cleanup,

            
            };


            static const struct drm_encoder_funcs ili9486_encoder_funcs = {

            
            	.destroy = drm_encoder_cleanup,

            
            };


            static const struct drm_connector_helper_funcs ili9486_connector_helper_funcs = {

            
            	DRM_MIPI_DBI_CONNECTOR_HELPER_FUNCS,

            
            };


            static const struct drm_connector_funcs ili9486_connector_funcs = {

            
            	DRM_MIPI_DBI_CONNECTOR_FUNCS,

            
            	.destroy = drm_connector_cleanup,

            
            };


            static const struct drm_mode_config_helper_funcs ili9486_mode_config_helper_funcs = {

            
            	DRM_MIPI_DBI_MODE_CONFIG_HELPER_FUNCS,

            
            };


            static const struct drm_mode_config_funcs ili9486_mode_config_funcs = {

            
            	DRM_MIPI_DBI_MODE_CONFIG_FUNCS,

            
            };


            static const struct drm_display_mode waveshare_mode = {

            
            	DRM_SIMPLE_MODE(480, 320, 73, 49),

            
            };


            DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops);


            static const struct drm_driver ili9486_driver = {

            
            	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,

            
            	.fops			= &ili9486_fops,

            
            	DRM_GEM_DMA_DRIVER_OPS_VMAP,

            
            	DRM_FBDEV_DMA_DRIVER_OPS,

            
            	.debugfs_init		= mipi_dbi_debugfs_init,

            
            	.name			= "ili9486",

            
            	.desc			= "Ilitek ILI9486",

            
            	.major			= 1,

            
            	.minor			= 0,

            
            };


            static const struct of_device_id ili9486_of_match[] = {

            
            	{ .compatible = "waveshare,rpi-lcd-35" },

            
            	{ .compatible = "ozzmaker,piscreen" },

            
            	{},

            
            };

            
            MODULE_DEVICE_TABLE(of, ili9486_of_match);


            static const struct spi_device_id ili9486_id[] = {

            
            	{ "ili9486", 0 },

            
            	{ "rpi-lcd-35", 0 },

            
            	{ "piscreen", 0 },

            
            	{ }

            
            };

            
            MODULE_DEVICE_TABLE(spi, ili9486_id);


            static int ili9486_probe(struct spi_device *spi)

            
            {

            
            	struct device *dev = &spi->dev;

            
            	struct ili9486_device *ili9486;

            
            	struct mipi_dbi_dev *dbidev;

            
            	struct drm_device *drm;

            
            	struct mipi_dbi *dbi;

            
            	struct gpio_desc *dc;

            
            	struct drm_plane *plane;

            
            	struct drm_crtc *crtc;

            
            	struct drm_encoder *encoder;

            
            	struct drm_connector *connector;

            
            	u32 rotation = 0;

            
            	int ret;


            	ili9486 = devm_drm_dev_alloc(dev, &ili9486_driver, struct ili9486_device, dbidev.drm);

            
            	if (IS_ERR(ili9486))

            
            		return PTR_ERR(ili9486);

            
            	dbidev = &ili9486->dbidev;

            
            	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;


            	dbi->command = waveshare_command;

            
            	dbi->read_commands = NULL;


            	ret = drm_mipi_dbi_dev_init(dbidev, &waveshare_mode, ili9486_plane_formats[0],

            
            				    rotation, 0);

            
            	if (ret)

            
            		return ret;


            	ret = drmm_mode_config_init(drm);

            
            	if (ret)

            
            		return ret;


            	drm->mode_config.min_width = dbidev->mode.hdisplay;

            
            	drm->mode_config.max_width = dbidev->mode.hdisplay;

            
            	drm->mode_config.min_height = dbidev->mode.vdisplay;

            
            	drm->mode_config.max_height = dbidev->mode.vdisplay;

            
            	drm->mode_config.funcs = &ili9486_mode_config_funcs;

            
            	drm->mode_config.preferred_depth = 16;

            
            	drm->mode_config.helper_private = &ili9486_mode_config_helper_funcs;


            	plane = &ili9486->plane;

            
            	ret = drm_universal_plane_init(drm, plane, 0, &ili9486_plane_funcs,

            
            				       ili9486_plane_formats, ARRAY_SIZE(ili9486_plane_formats),

            
            				       ili9486_plane_format_modifiers,

            
            				       DRM_PLANE_TYPE_PRIMARY, NULL);

            
            	if (ret)

            
            		return ret;

            
            	drm_plane_helper_add(plane, &ili9486_plane_helper_funcs);

            
            	drm_plane_enable_fb_damage_clips(plane);


            	crtc = &ili9486->crtc;

            
            	ret = drm_crtc_init_with_planes(drm, crtc, plane, NULL, &ili9486_crtc_funcs, NULL);

            
            	if (ret)

            
            		return ret;

            
            	drm_crtc_helper_add(crtc, &ili9486_crtc_helper_funcs);


            	encoder = &ili9486->encoder;

            
            	ret = drm_encoder_init(drm, encoder, &ili9486_encoder_funcs, DRM_MODE_ENCODER_NONE, NULL);

            
            	if (ret)

            
            		return ret;

            
            	encoder->possible_crtcs = drm_crtc_mask(crtc);


            	connector = &ili9486->connector;

            
            	ret = drm_connector_init(drm, connector, &ili9486_connector_funcs,

            
            				 DRM_MODE_CONNECTOR_SPI);

            
            	if (ret)

            
            		return ret;

            
            	drm_connector_helper_add(connector, &ili9486_connector_helper_funcs);


            	ret = drm_connector_attach_encoder(connector, encoder);

            
            	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_client_setup(drm, NULL);


            	return 0;

            
            }


            static void ili9486_remove(struct spi_device *spi)

            
            {

            
            	struct drm_device *drm = spi_get_drvdata(spi);


            	drm_dev_unplug(drm);

            
            	drm_atomic_helper_shutdown(drm);

            
            }


            static void ili9486_shutdown(struct spi_device *spi)

            
            {

            
            	drm_atomic_helper_shutdown(spi_get_drvdata(spi));

            
            }


            static struct spi_driver ili9486_spi_driver = {

            
            	.driver = {

            
            		.name = "ili9486",

            
            		.of_match_table = ili9486_of_match,

            
            	},

            
            	.id_table = ili9486_id,

            
            	.probe = ili9486_probe,

            
            	.remove = ili9486_remove,

            
            	.shutdown = ili9486_shutdown,

            
            };

            
            module_spi_driver(ili9486_spi_driver);


            MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");

            
            MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");

            
            MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* DRM driver for Ilitek ILI9486 panels
	*
	* Copyright 2020 Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>
	*/

	#include <linux/backlight.h>
	#include <linux/delay.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/clients/drm_client_setup.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>
	#include <drm/drm_modeset_helper.h>
	#include <drm/drm_print.h>

	#define ILI9486_ITFCTR1 0xb0
	#define ILI9486_PWCTRL1 0xc2
	#define ILI9486_VMCTRL1 0xc5
	#define ILI9486_PGAMCTRL 0xe0
	#define ILI9486_NGAMCTRL 0xe1
	#define ILI9486_DGAMCTRL 0xe2
	#define ILI9486_MADCTL_BGR BIT(3)
	#define ILI9486_MADCTL_MV BIT(5)
	#define ILI9486_MADCTL_MX BIT(6)
	#define ILI9486_MADCTL_MY BIT(7)

	struct ili9486_device {
	struct mipi_dbi_dev dbidev;

	struct drm_plane plane;
	struct drm_crtc crtc;
	struct drm_encoder encoder;
	struct drm_connector connector;
	};

	static struct ili9486_device to_ili9486_device(struct drm_device dev)
	{
	return container_of(drm_to_mipi_dbi_dev(dev), struct ili9486_device, dbidev);
	}

	/*
	* The PiScreen/waveshare rpi-lcd-35 has a SPI to 16-bit parallel bus converter
	* in front of the display controller. This means that 8-bit values have to be
	* transferred as 16-bit.
	*/
	static int waveshare_command(struct mipi_dbi mipi, u8 cmd, u8 *par,
	size_t num)
	{
	struct spi_device *spi = mipi->spi;
	unsigned int bpw = 8;
	void *data = par;
	u32 speed_hz;
	int i, ret;
	__be16 *buf;

	buf = kmalloc(32 * sizeof(u16), GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	/*
	* The displays are Raspberry Pi HATs and connected to the 8-bit only
	* SPI controller, so 16-bit command and parameters need byte swapping
	* before being transferred as 8-bit on the big endian SPI bus.
	*/
	buf[0] = cpu_to_be16(*cmd);
	spi_bus_lock(spi->controller);
	gpiod_set_value_cansleep(mipi->dc, 0);
	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);
	ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);
	spi_bus_unlock(spi->controller);
	if (ret \|\| !num)
	goto free;

	/* 8-bit configuration data, not 16-bit pixel data */
	if (num <= 32) {
	for (i = 0; i < num; i++)
	buf[i] = cpu_to_be16(par[i]);
	num *= 2;
	data = buf;
	}

	/*
	* Check whether pixel data bytes needs to be swapped or not
	*/
	if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)
	bpw = 16;

	spi_bus_lock(spi->controller);
	gpiod_set_value_cansleep(mipi->dc, 1);
	speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
	ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);
	spi_bus_unlock(spi->controller);
	free:
	kfree(buf);

	return ret;
	}

	static const u32 ili9486_plane_formats[] = {
	DRM_MIPI_DBI_PLANE_FORMATS,
	};

	static const u64 ili9486_plane_format_modifiers[] = {
	DRM_MIPI_DBI_PLANE_FORMAT_MODIFIERS,
	};

	static const struct drm_plane_helper_funcs ili9486_plane_helper_funcs = {
	DRM_MIPI_DBI_PLANE_HELPER_FUNCS,
	};

	static const struct drm_plane_funcs ili9486_plane_funcs = {
	DRM_MIPI_DBI_PLANE_FUNCS,
	.destroy = drm_plane_cleanup,
	};

	static void ili9486_crtc_helper_atomic_enable(struct drm_crtc *crtc,
	struct drm_atomic_commit *state)
	{
	struct drm_device *drm = crtc->dev;
	struct ili9486_device *ili9486 = to_ili9486_device(drm);
	struct mipi_dbi_dev *dbidev = &ili9486->dbidev;
	struct mipi_dbi *dbi = &dbidev->dbi;
	u8 addr_mode;
	int ret, idx;

	if (!drm_dev_enter(drm, &idx))
	return;

	DRM_DEBUG_KMS("\n");

	ret = mipi_dbi_poweron_conditional_reset(dbidev);
	if (ret < 0)
	goto out_exit;
	if (ret == 1)
	goto out_enable;

	mipi_dbi_command(dbi, ILI9486_ITFCTR1);
	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
	msleep(250);

	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);

	mipi_dbi_command(dbi, ILI9486_PWCTRL1, 0x44);

	mipi_dbi_command(dbi, ILI9486_VMCTRL1, 0x00, 0x00, 0x00, 0x00);

	mipi_dbi_command(dbi, ILI9486_PGAMCTRL,
	0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98,
	0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x0);
	mipi_dbi_command(dbi, ILI9486_NGAMCTRL,
	0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
	0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);
	mipi_dbi_command(dbi, ILI9486_DGAMCTRL,
	0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75,
	0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00);

	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
	msleep(100);

	out_enable:
	switch (dbidev->rotation) {
	case 90:
	addr_mode = ILI9486_MADCTL_MY;
	break;
	case 180:
	addr_mode = ILI9486_MADCTL_MV;
	break;
	case 270:
	addr_mode = ILI9486_MADCTL_MX;
	break;
	default:
	addr_mode = ILI9486_MADCTL_MV \| ILI9486_MADCTL_MY \|
	ILI9486_MADCTL_MX;
	break;
	}
	addr_mode \|= ILI9486_MADCTL_BGR;
	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);

	backlight_enable(dbidev->backlight);
	out_exit:
	drm_dev_exit(idx);
	}

	static const struct drm_crtc_helper_funcs ili9486_crtc_helper_funcs = {
	DRM_MIPI_DBI_CRTC_HELPER_FUNCS,
	.atomic_enable = ili9486_crtc_helper_atomic_enable,
	};

	static const struct drm_crtc_funcs ili9486_crtc_funcs = {
	DRM_MIPI_DBI_CRTC_FUNCS,
	.destroy = drm_crtc_cleanup,
	};

	static const struct drm_encoder_funcs ili9486_encoder_funcs = {
	.destroy = drm_encoder_cleanup,
	};

	static const struct drm_connector_helper_funcs ili9486_connector_helper_funcs = {
	DRM_MIPI_DBI_CONNECTOR_HELPER_FUNCS,
	};

	static const struct drm_connector_funcs ili9486_connector_funcs = {
	DRM_MIPI_DBI_CONNECTOR_FUNCS,
	.destroy = drm_connector_cleanup,
	};

	static const struct drm_mode_config_helper_funcs ili9486_mode_config_helper_funcs = {
	DRM_MIPI_DBI_MODE_CONFIG_HELPER_FUNCS,
	};

	static const struct drm_mode_config_funcs ili9486_mode_config_funcs = {
	DRM_MIPI_DBI_MODE_CONFIG_FUNCS,
	};

	static const struct drm_display_mode waveshare_mode = {
	DRM_SIMPLE_MODE(480, 320, 73, 49),
	};

	DEFINE_DRM_GEM_DMA_FOPS(ili9486_fops);

	static const struct drm_driver ili9486_driver = {
	.driver_features = DRIVER_GEM \| DRIVER_MODESET \| DRIVER_ATOMIC,
	.fops = &ili9486_fops,
	DRM_GEM_DMA_DRIVER_OPS_VMAP,
	DRM_FBDEV_DMA_DRIVER_OPS,
	.debugfs_init = mipi_dbi_debugfs_init,
	.name = "ili9486",
	.desc = "Ilitek ILI9486",
	.major = 1,
	.minor = 0,
	};

	static const struct of_device_id ili9486_of_match[] = {
	{ .compatible = "waveshare,rpi-lcd-35" },
	{ .compatible = "ozzmaker,piscreen" },
	{},
	};
	MODULE_DEVICE_TABLE(of, ili9486_of_match);

	static const struct spi_device_id ili9486_id[] = {
	{ "ili9486", 0 },
	{ "rpi-lcd-35", 0 },
	{ "piscreen", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(spi, ili9486_id);

	static int ili9486_probe(struct spi_device *spi)
	{
	struct device *dev = &spi->dev;
	struct ili9486_device *ili9486;
	struct mipi_dbi_dev *dbidev;
	struct drm_device *drm;
	struct mipi_dbi *dbi;
	struct gpio_desc *dc;
	struct drm_plane *plane;
	struct drm_crtc *crtc;
	struct drm_encoder *encoder;
	struct drm_connector *connector;
	u32 rotation = 0;
	int ret;

	ili9486 = devm_drm_dev_alloc(dev, &ili9486_driver, struct ili9486_device, dbidev.drm);
	if (IS_ERR(ili9486))
	return PTR_ERR(ili9486);
	dbidev = &ili9486->dbidev;
	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;

	dbi->command = waveshare_command;
	dbi->read_commands = NULL;

	ret = drm_mipi_dbi_dev_init(dbidev, &waveshare_mode, ili9486_plane_formats[0],
	rotation, 0);
	if (ret)
	return ret;

	ret = drmm_mode_config_init(drm);
	if (ret)
	return ret;

	drm->mode_config.min_width = dbidev->mode.hdisplay;
	drm->mode_config.max_width = dbidev->mode.hdisplay;
	drm->mode_config.min_height = dbidev->mode.vdisplay;
	drm->mode_config.max_height = dbidev->mode.vdisplay;
	drm->mode_config.funcs = &ili9486_mode_config_funcs;
	drm->mode_config.preferred_depth = 16;
	drm->mode_config.helper_private = &ili9486_mode_config_helper_funcs;

	plane = &ili9486->plane;
	ret = drm_universal_plane_init(drm, plane, 0, &ili9486_plane_funcs,
	ili9486_plane_formats, ARRAY_SIZE(ili9486_plane_formats),
	ili9486_plane_format_modifiers,
	DRM_PLANE_TYPE_PRIMARY, NULL);
	if (ret)
	return ret;
	drm_plane_helper_add(plane, &ili9486_plane_helper_funcs);
	drm_plane_enable_fb_damage_clips(plane);

	crtc = &ili9486->crtc;
	ret = drm_crtc_init_with_planes(drm, crtc, plane, NULL, &ili9486_crtc_funcs, NULL);
	if (ret)
	return ret;
	drm_crtc_helper_add(crtc, &ili9486_crtc_helper_funcs);

	encoder = &ili9486->encoder;
	ret = drm_encoder_init(drm, encoder, &ili9486_encoder_funcs, DRM_MODE_ENCODER_NONE, NULL);
	if (ret)
	return ret;
	encoder->possible_crtcs = drm_crtc_mask(crtc);

	connector = &ili9486->connector;
	ret = drm_connector_init(drm, connector, &ili9486_connector_funcs,
	DRM_MODE_CONNECTOR_SPI);
	if (ret)
	return ret;
	drm_connector_helper_add(connector, &ili9486_connector_helper_funcs);

	ret = drm_connector_attach_encoder(connector, encoder);
	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_client_setup(drm, NULL);

	return 0;
	}

	static void ili9486_remove(struct spi_device *spi)
	{
	struct drm_device *drm = spi_get_drvdata(spi);

	drm_dev_unplug(drm);
	drm_atomic_helper_shutdown(drm);
	}

	static void ili9486_shutdown(struct spi_device *spi)
	{
	drm_atomic_helper_shutdown(spi_get_drvdata(spi));
	}

	static struct spi_driver ili9486_spi_driver = {
	.driver = {
	.name = "ili9486",
	.of_match_table = ili9486_of_match,
	},
	.id_table = ili9486_id,
	.probe = ili9486_probe,
	.remove = ili9486_remove,
	.shutdown = ili9486_shutdown,
	};
	module_spi_driver(ili9486_spi_driver);

	MODULE_DESCRIPTION("Ilitek ILI9486 DRM driver");
	MODULE_AUTHOR("Kamlesh Gurudasani <kamlesh.gurudasani@gmail.com>");
	MODULE_LICENSE("GPL");