DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C0BF6120A
Date: Wed, 21 Jul 2021 18:56:53 +0200
From: Sam Ravnborg <sam@ravnborg.org>
To: dillon.minfei@gmail.com
Subject: Re: [PATCH v2 3/3] drm/panel: Add ilitek ili9341 panel driver
Message-ID: <YPhR1citK6Nodep/@ravnborg.org>
References: <1626853288-31223-1-git-send-email-dillon.minfei@gmail.com>
 <1626853288-31223-4-git-send-email-dillon.minfei@gmail.com>
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Hi Dillon,

On Wed, Jul 21, 2021 at 03:41:28PM +0800, dillon.minfei@gmail.com wrote:
> From: Dillon Min <dillon.minfei@gmail.com>
> 
> This driver combine tiny/ili9341.c mipi_dbi_interface driver
> with mipi_dpi_interface driver, can support ili9341 with serial
> mode or parallel rgb interface mode by register configuration.
> 
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Dillon Min <dillon.minfei@gmail.com>

I have not looked at the driver before, sorry for being late.
A few nits in the following.

	Sam

> +#include <linux/bitops.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
> +#include <linux/delay.h>
> +#include <video/mipi_display.h>
> +#include <drm/drm_mipi_dbi.h>
> +#include <drm/drm_gem_framebuffer_helper.h>
> +#include <drm/drm_gem_cma_helper.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_gem_atomic_helper.h>
> +
> +#include <drm/drm_drv.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>

Spaces between blocks of includes.
So linux/* goes in one block, video/* in next block, drm/* in the last
block.
Sort alphabetically in each block.

> +
> +/**
> + * struct ili9341_config - the system specific ILI9341 configuration
> + * @max_spi_speed: 10000000
> + */
Unless you plan to pull this into our kernel-doc there is really no need
for a kernel-doc marker. On the other hand W=1 builds will tell if you
missed something. So there are arguments both ways.

> +struct ili9341_config {
> +	u32 max_spi_speed;
> +	/** @mode: the drm display mode */
> +	const struct drm_display_mode mode;
> +	/** @ca: TODO: need comments for this register */
> +	u8 ca[ILI9341_CA_LEN];
> +	/** @power_b: TODO: need comments for this register */
> +	u8 power_b[ILI9341_POWER_B_LEN];
> +	/** @power_seq: TODO: need comments for this register */
> +	u8 power_seq[ILI9341_POWER_SEQ_LEN];
> +	/** @dtca: TODO: need comments for this register */
> +	u8 dtca[ILI9341_DTCA_LEN];
> +	/** @dtcb: TODO: need comments for this register */
> +	u8 dtcb[ILI9341_DTCB_LEN];
> +	/** @power_a: TODO: need comments for this register */
> +	u8 power_a[ILI9341_POWER_A_LEN];
> +	/** @frc: Frame Rate Control (In Normal Mode/Full Colors) (B1h) */
> +	u8 frc[ILI9341_FRC_LEN];
> +	/** @prc: TODO: need comments for this register */
> +	u8 prc;
> +	/** @dfc_1: B6h DISCTRL (Display Function Control) */
> +	u8 dfc_1[ILI9341_DFC_1_LEN];
> +	/** @power_1: Power Control 1 (C0h) */
> +	u8 power_1;
> +	/** @power_2: Power Control 2 (C1h) */
> +	u8 power_2;
> +	/** @vcom_1: VCOM Control 1(C5h) */
> +	u8 vcom_1[ILI9341_VCOM_1_LEN];
> +	/** @vcom_2: VCOM Control 2(C7h) */
> +	u8 vcom_2;
> +	/** @address_mode: Memory Access Control (36h) */
> +	u8 address_mode;
> +	/** @g3amma_en: TODO: need comments for this register */
> +	u8 g3amma_en;
> +	/** @rgb_interface: RGB Interface Signal Control (B0h) */
> +	u8 rgb_interface;
> +	/** @dfc_2: refer to dfc_1 */
> +	u8 dfc_2[ILI9341_DFC_2_LEN];
> +	/** @column_addr: Column Address Set (2Ah) */
> +	u8 column_addr[ILI9341_COLUMN_ADDR_LEN];
> +	/** @page_addr: Page Address Set (2Bh) */
> +	u8 page_addr[ILI9341_PAGE_ADDR_LEN];
> +	/** @interface: Interface Control (F6h) */
> +	u8 interface[ILI9341_INTERFACE_LEN];
> +	/** @pixel_format: This command sets the pixel format for the RGB */
> +	/* image data used by
> +	 */
> +	u8 pixel_format;
> +	/** @gamma_curve: This command is used to select the desired Gamma */
> +	/* curve for the
> +	 */
Make this a single comment block.

> +	u8 gamma_curve;
> +	/** @pgamma: Positive Gamma Correction (E0h) */
> +	u8 pgamma[ILI9341_PGAMMA_LEN];
> +	/** @ngamma: Negative Gamma Correction (E1h) */
> +	u8 ngamma[ILI9341_NGAMMA_LEN];
> +};
> +
> +struct ili9341 {
> +	struct device *dev;
We will have struct device * both in drm_panel and in ili9341.
You could brop the one in ili9341.

> +	const struct ili9341_config *conf;
> +	struct drm_panel panel;
> +	struct gpio_desc *reset_gpio;
> +	struct gpio_desc *dc_gpio;
> +	struct mipi_dbi *dbi;
> +	u32 max_spi_speed;
> +	struct regulator_bulk_data supplies[3];
> +};
> +
> +/*
> + * The Stm32f429-disco board has a panel ili9341 connected to ltdc controller
> + */
> +static const struct ili9341_config ili9341_stm32f429_disco_data = {
> +	.max_spi_speed = 10000000,
> +	.mode = {
> +		.clock = 6100,
> +		.hdisplay = 240,
> +		.hsync_start = 240 + 10,/* hfp 10 */
> +		.hsync_end = 240 + 10 + 10,/* hsync 10 */
> +		.htotal = 240 + 10 + 10 + 20,/* hbp 20 */
> +		.vdisplay = 320,
> +		.vsync_start = 320 + 4,/* vfp 4 */
> +		.vsync_end = 320 + 4 + 2,/* vsync 2 */
> +		.vtotal = 320 + 4 + 2 + 2,/* vbp 2 */
> +		.flags = 0,
> +		.width_mm = 65,
> +		.height_mm = 50,
> +		.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +	},
> +	.ca = {0xc3, 0x08, 0x50},
> +	.power_b = {0x00, 0xc1, 0x30},
> +	.power_seq = {0x64, 0x03, 0x12, 0x81},
> +	.dtca = {0x85, 0x00, 0x78},
> +	.power_a = {0x39, 0x2c, 0x00, 0x34, 0x02},
> +	.prc = 0x20,
> +	.dtcb = {0x00, 0x00},
> +	/* 0x00 fosc, 0x1b 70hz */
> +	.frc = {0x00, 0x1b},
> +	/* 0x0a Interval scan, AGND AGND AGND AGND
> +	 * 0xa2 Normally white, G1 -> G320, S720 -> S1,
> +	 *	Scan Cycle 5 frames,85ms
> +	 */
> +	.dfc_1 = {0x0a, 0xa2},
> +	/* 0x10 3.65v */
> +	.power_1 = 0x10,
> +	/* 0x10 AVDD=vci*2, VGH=vci*7, VGL=-vci*4 */
> +	.power_2 = 0x10,
> +	/* 0x45 VCOMH 4.425v, 0x15 VCOML -1.975*/
> +	.vcom_1 = {0x45, 0x15},
> +	/* 0x90 offset voltage, VMH-48, VML-48 */
> +	.vcom_2 = 0x90,
> +	/* 0xc8 Row Address Order, Column Address Order
> +	 * BGR 1
> +	 */
> +	.address_mode = 0xc8,
> +	.g3amma_en = 0x00,
> +	/* 0xc2
> +	 * Display Data Path: Memory
> +	 * RGB: DE mode
> +	 * DOTCLK polarity set (data fetched at the falling time)
> +	 */
> +	.rgb_interface = ILI9341_RGB_DISP_PATH_MEM |
> +			ILI9341_RGB_DE_MODE |
> +			ILI9341_RGB_DPL,
> +	/*
> +	 * 0x0a
> +	 * Gate outputs in non-display area: Interval scan
> +	 * Determine source/VCOM output in a non-display area in the partial
> +	 * display mode: AGND AGND AGND AGND
> +	 *
> +	 * 0xa7
> +	 * Scan Cycle: 15 frames
> +	 * fFLM = 60Hz: 255ms
> +	 * Liquid crystal type: Normally white
> +	 * Gate Output Scan Direction: G1 -> G320
> +	 * Source Output Scan Direction: S720 -> S1
> +	 *
> +	 * 0x27
> +	 * LCD Driver Line: 320 lines
> +	 *
> +	 * 0x04
> +	 * PCDIV: 4
> +	 */
> +	.dfc_2 = {0x0a, 0xa7, 0x27, 0x04},
> +	/* column address: 240 */
> +	.column_addr = {0x00, 0x00, (ILI9341_COLUMN_ADDR >> 4) & 0xff,
> +				ILI9341_COLUMN_ADDR & 0xff},
> +	/* page address: 320 */
> +	.page_addr = {0x00, 0x00, (ILI9341_PAGE_ADDR >> 4) & 0xff,
> +				ILI9341_PAGE_ADDR & 0xff},
> +	/* Memory write control: When the transfer number of data exceeds
> +	 * (EC-SC+1)*(EP-SP+1), the column and page number will be
> +	 * reset, and the exceeding data will be written into the following
> +	 * column and page.
> +	 * Display Operation Mode: RGB Interface Mode
> +	 * Interface for RAM Access: RGB interface
> +	 * 16- bit RGB interface (1 transfer/pixel)
> +	 */
> +	.interface = {ILI9341_IF_WE_MODE, 0x00,
> +			ILI9341_IF_DM_RGB | ILI9341_IF_RM_RGB},
> +	/* DPI: 16 bits / pixel */
> +	.pixel_format = ILI9341_PIXEL_DPI_16_BITS,
> +	/* Curve Selected: Gamma curve 1 (G2.2) */
> +	.gamma_curve = ILI9341_GAMMA_CURVE_1,
> +	.pgamma = {0x0f, 0x29, 0x24, 0x0c, 0x0e,
> +			0x09, 0x4e, 0x78, 0x3c, 0x09,
> +			0x13, 0x05, 0x17, 0x11, 0x00},
> +	.ngamma = {0x00, 0x16, 0x1b, 0x04, 0x11,
> +			0x07, 0x31, 0x33, 0x42, 0x05,
> +			0x0c, 0x0a, 0x28, 0x2f, 0x0f},
> +};
> +
> +static inline struct ili9341 *panel_to_ili9341(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct ili9341, panel);
> +}
> +
> +static void ili9341_dpi_init(struct ili9341 *ili)
> +{
> +	struct mipi_dbi *dbi = ili->dbi;
> +	struct ili9341_config *cfg = (struct ili9341_config *)ili->conf;
> +
> +	/* Power Control */
> +	mipi_dbi_command_stackbuf(dbi, 0xca, cfg->ca, ILI9341_CA_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_POWERB, cfg->power_b,
> +				  ILI9341_POWER_B_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_POWER_SEQ, cfg->power_seq,
> +				  ILI9341_POWER_SEQ_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_DTCA, cfg->dtca,
> +				  ILI9341_DTCA_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_POWERA, cfg->power_a,
> +				  ILI9341_POWER_A_LEN);
> +	mipi_dbi_command(ili->dbi, ILI9341_PRC, cfg->prc);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_DTCB, cfg->dtcb,
> +				  ILI9341_DTCB_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_FRC, cfg->frc, ILI9341_FRC_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_DFC, cfg->dfc_1,
> +				  ILI9341_DFC_1_LEN);
> +	mipi_dbi_command(dbi, ILI9341_POWER1, cfg->power_1);
> +	mipi_dbi_command(dbi, ILI9341_POWER2, cfg->power_2);
> +
> +	/* VCOM */
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_VCOM1, cfg->vcom_1,
> +				  ILI9341_VCOM_1_LEN);
> +	mipi_dbi_command(dbi, ILI9341_VCOM2, cfg->vcom_2);
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, cfg->address_mode);
> +
> +	/* Gamma */
> +	mipi_dbi_command(dbi, ILI9341_3GAMMA_EN, cfg->g3amma_en);
> +	mipi_dbi_command(dbi, ILI9341_RGB_INTERFACE, cfg->rgb_interface);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_DFC, cfg->dfc_2,
> +				  ILI9341_DFC_2_LEN);
> +
> +	/* Colomn address set */
> +	mipi_dbi_command_stackbuf(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
> +				  cfg->column_addr, ILI9341_COLUMN_ADDR_LEN);
> +
> +	/* Page address set */
> +	mipi_dbi_command_stackbuf(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
> +				  cfg->page_addr, ILI9341_PAGE_ADDR_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_INTERFACE, cfg->interface,
> +				  ILI9341_INTERFACE_LEN);
> +
> +	/* Format */
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, cfg->pixel_format);
> +	mipi_dbi_command(dbi, MIPI_DCS_WRITE_MEMORY_START);
> +	msleep(200);
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_GAMMA_CURVE, cfg->gamma_curve);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_PGAMMA, cfg->pgamma,
> +				  ILI9341_PGAMMA_LEN);
> +	mipi_dbi_command_stackbuf(dbi, ILI9341_NGAMMA, cfg->ngamma,
> +				  ILI9341_NGAMMA_LEN);
> +	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
> +	msleep(200);
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
> +	mipi_dbi_command(dbi, MIPI_DCS_WRITE_MEMORY_START);
> +
> +	dev_info(ili->dev, "initialized display rgb interface\n");
> +}
> +
> +static int ili9341_dpi_power_on(struct ili9341 *ili)
> +{
> +	int ret = 0;
> +
> +	/* Assert RESET */
> +	gpiod_set_value(ili->reset_gpio, 1);
> +
> +	/* Enable power */
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ili->supplies),
> +				    ili->supplies);
> +	if (ret < 0) {
> +		dev_err(ili->dev, "unable to enable vcc\n");
> +		return ret;
> +	}
> +	msleep(20);
> +
> +	/* De-assert RESET */
> +	gpiod_set_value(ili->reset_gpio, 0);
> +	msleep(20);
> +
> +	return 0;
> +}
> +
> +static int ili9341_dpi_power_off(struct ili9341 *ili)
> +{
> +	/* Assert RESET */
> +	gpiod_set_value(ili->reset_gpio, 1);
> +
> +	/* Disable power */
> +	return regulator_bulk_disable(ARRAY_SIZE(ili->supplies),
> +				      ili->supplies);
> +}
> +
> +static int ili9341_dpi_disable(struct drm_panel *panel)
> +{
> +	struct ili9341 *ili = panel_to_ili9341(panel);
> +
> +	mipi_dbi_command(ili->dbi, MIPI_DCS_SET_DISPLAY_OFF);
> +	return 0;
> +}
> +
> +static int ili9341_dpi_unprepare(struct drm_panel *panel)
> +{
> +	struct ili9341 *ili = panel_to_ili9341(panel);
> +
> +	return ili9341_dpi_power_off(ili);
> +}
> +
> +static int ili9341_dpi_prepare(struct drm_panel *panel)
> +{
> +	struct ili9341 *ili = panel_to_ili9341(panel);
> +	int ret;
> +
> +	ret = ili9341_dpi_power_on(ili);
> +	if (ret < 0)
> +		return ret;
> +
> +	ili9341_dpi_init(ili);
> +
> +	return ret;
> +}
> +
> +static int ili9341_dpi_enable(struct drm_panel *panel)
> +{
> +	struct ili9341 *ili = panel_to_ili9341(panel);
> +
> +	mipi_dbi_command(ili->dbi, MIPI_DCS_SET_DISPLAY_ON);
> +	return 0;
> +}
> +
> +static int ili9341_dpi_get_modes(struct drm_panel *panel,
> +				 struct drm_connector *connector)
> +{
> +	struct ili9341 *ili = panel_to_ili9341(panel);
> +	struct drm_device *drm = connector->dev;
> +	struct drm_display_mode *mode;
> +	struct drm_display_info *info;
> +
> +	info = &connector->display_info;
> +	info->width_mm = ili->conf->mode.width_mm;
> +	info->height_mm = ili->conf->mode.height_mm;
> +
> +	if (ili->conf->rgb_interface & ILI9341_RGB_DPL)
> +		info->bus_flags |= DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE;
> +	else
> +		info->bus_flags |= DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
> +
> +	if (ili->conf->rgb_interface & ILI9341_RGB_EPL)
> +		info->bus_flags |= DRM_BUS_FLAG_DE_LOW;
> +	else
> +		info->bus_flags |= DRM_BUS_FLAG_DE_HIGH;
> +
> +	mode = drm_mode_duplicate(drm, &ili->conf->mode);
> +	if (!mode) {
> +		DRM_ERROR("bad mode or failed to add mode\n");

DRM_ERROR and friends are not used in panel/* - the new variants
drm_err() shall be used.
This goes for the other uses of DRM_* as well.

> +		return -EINVAL;
> +	}
> +	drm_mode_set_name(mode);
> +
> +	/* Set up the polarity */
> +	if (ili->conf->rgb_interface & ILI9341_RGB_HSPL)
> +		mode->flags |= DRM_MODE_FLAG_PHSYNC;
> +	else
> +		mode->flags |= DRM_MODE_FLAG_NHSYNC;
> +
> +	if (ili->conf->rgb_interface & ILI9341_RGB_VSPL)
> +		mode->flags |= DRM_MODE_FLAG_PVSYNC;
> +	else
> +		mode->flags |= DRM_MODE_FLAG_NVSYNC;
> +
> +	drm_mode_probed_add(connector, mode);
> +
> +	return 1; /* Number of modes */
> +}
> +
> +static const struct drm_panel_funcs ili9341_dpi_funcs = {
> +	.disable = ili9341_dpi_disable,
> +	.unprepare = ili9341_dpi_unprepare,
> +	.prepare = ili9341_dpi_prepare,
> +	.enable = ili9341_dpi_enable,
> +	.get_modes = ili9341_dpi_get_modes,
> +};
> +
> +static void ili9341_dbi_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 mipi_dbi *dbi = &dbidev->dbi;
> +	u8 addr_mode;
> +	int ret, idx;
> +
> +	if (!drm_dev_enter(pipe->crtc.dev, &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, MIPI_DCS_SET_DISPLAY_OFF);
> +
> +	mipi_dbi_command(dbi, ILI9341_POWERB, 0x00, 0xc1, 0x30);
> +	mipi_dbi_command(dbi, ILI9341_POWER_SEQ, 0x64, 0x03, 0x12, 0x81);
> +	mipi_dbi_command(dbi, ILI9341_DTCA, 0x85, 0x00, 0x78);
> +	mipi_dbi_command(dbi, ILI9341_POWERA, 0x39, 0x2c, 0x00, 0x34, 0x02);
> +	mipi_dbi_command(dbi, ILI9341_PRC, ILI9341_DBI_PRC_NORMAL);
> +	mipi_dbi_command(dbi, ILI9341_DTCB, 0x00, 0x00);
> +
> +	/* Power Control */
> +	mipi_dbi_command(dbi, ILI9341_POWER1, ILI9341_DBI_VCOMH_4P6V);
> +	mipi_dbi_command(dbi, ILI9341_POWER2, ILI9341_DBI_PWR_2_DEFAULT);
> +	/* VCOM */
> +	mipi_dbi_command(dbi, ILI9341_VCOM1, ILI9341_DBI_VCOM_1_VMH_4P25V,
> +			 ILI9341_DBI_VCOM_1_VML_1P5V);
> +	mipi_dbi_command(dbi, ILI9341_VCOM2, ILI9341_DBI_VCOM_2_DEC_58);
> +
> +	/* Memory Access Control */
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT,
> +			 MIPI_DCS_PIXEL_FMT_16BIT);
> +
> +	/* Frame Rate */
> +	mipi_dbi_command(dbi, ILI9341_FRC, ILI9341_DBI_FRC_DIVA & 0x03,
> +			 ILI9341_DBI_FRC_RTNA & 0x1f);
> +
> +	/* Gamma */
> +	mipi_dbi_command(dbi, ILI9341_3GAMMA_EN, 0x00);
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_GAMMA_CURVE, ILI9341_GAMMA_CURVE_1);
> +	mipi_dbi_command(dbi, ILI9341_PGAMMA,
> +			 0x0f, 0x31, 0x2b, 0x0c, 0x0e, 0x08, 0x4e, 0xf1,
> +			 0x37, 0x07, 0x10, 0x03, 0x0e, 0x09, 0x00);
> +	mipi_dbi_command(dbi, ILI9341_NGAMMA,
> +			 0x00, 0x0e, 0x14, 0x03, 0x11, 0x07, 0x31, 0xc1,
> +			 0x48, 0x08, 0x0f, 0x0c, 0x31, 0x36, 0x0f);
> +
> +	/* DDRAM */
> +	mipi_dbi_command(dbi, ILI9341_ETMOD, ILI9341_DBI_EMS_GAS |
> +			 ILI9341_DBI_EMS_DTS |
> +			 ILI9341_DBI_EMS_GON);
> +
> +	/* Display */
> +	mipi_dbi_command(dbi, ILI9341_DFC, 0x08, 0x82, 0x27, 0x00);
> +	mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
> +	msleep(100);
> +
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
> +	msleep(100);
> +
> +out_enable:
> +	switch (dbidev->rotation) {
> +	default:
> +		addr_mode = ILI9341_MADCTL_MX;
> +		break;
> +	case 90:
> +		addr_mode = ILI9341_MADCTL_MV;
> +		break;
> +	case 180:
> +		addr_mode = ILI9341_MADCTL_MY;
> +		break;
> +	case 270:
> +		addr_mode = ILI9341_MADCTL_MV | ILI9341_MADCTL_MY |
> +			    ILI9341_MADCTL_MX;
> +		break;
> +	}
> +	addr_mode |= ILI9341_MADCTL_BGR;
> +	mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
> +	mipi_dbi_enable_flush(dbidev, crtc_state, plane_state);
> +	DRM_DEBUG_KMS("initialized display serial interface\n");
> +out_exit:
> +	drm_dev_exit(idx);
> +}
> +
> +static const struct drm_simple_display_pipe_funcs ili9341_dbi_funcs = {
> +	.enable = ili9341_dbi_enable,
> +	.disable = mipi_dbi_pipe_disable,
> +	.update = mipi_dbi_pipe_update,
> +	.prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
> +};

So this is a full display driver. The more relevant home for this driver
is inside drm/tiny/.

> +
> +static const struct drm_display_mode ili9341_dbi_mode = {
> +	DRM_SIMPLE_MODE(240, 320, 37, 49),
> +};
> +
> +DEFINE_DRM_GEM_CMA_FOPS(ili9341_dbi_fops);
> +
> +static struct drm_driver ili9341_dbi_driver = {
> +	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
> +	.fops			= &ili9341_dbi_fops,
> +	DRM_GEM_CMA_DRIVER_OPS_VMAP,
> +	.debugfs_init		= mipi_dbi_debugfs_init,
> +	.name			= "ili9341",
> +	.desc			= "Ilitek ILI9341",
> +	.date			= "20210716",
> +	.major			= 1,
> +	.minor			= 0,
> +};
> +
> +static int _ili9341_probe(struct spi_device *spi, bool dpi)
> +{
> +	struct gpio_desc *dc;
> +	struct gpio_desc *reset;
> +	struct device *dev = &spi->dev;
> +	int ret;
> +
> +	reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(reset))
> +		DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
> +
> +	dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
> +	if (IS_ERR(dc))
> +		DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
> +
> +	if (!dpi) {
> +		struct mipi_dbi_dev *dbidev;
> +		struct mipi_dbi *dbi;
> +		struct drm_device *drm;
> +		struct regulator *vcc;
> +		u32 rotation = 0;
> +
> +		vcc = devm_regulator_get_optional(dev, "vcc");
> +		if (IS_ERR(vcc))
> +			DRM_DEV_ERROR(dev, "get optional vcc failed\n");
> +
> +		dbidev = devm_drm_dev_alloc(dev, &ili9341_dbi_driver,
> +					    struct mipi_dbi_dev, drm);
> +		if (IS_ERR(dbidev))
> +			return PTR_ERR(dbidev);
> +
> +		dbi = &dbidev->dbi;
> +		drm = &dbidev->drm;
> +		dbi->reset = reset;
> +		dbidev->regulator = vcc;
> +
> +		drm_mode_config_init(drm);
> +		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;
> +
> +		ret = mipi_dbi_dev_init(dbidev, &ili9341_dbi_funcs,
> +					&ili9341_dbi_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);
> +	} else {
> +		struct ili9341 *ili;
> +
> +		ili = devm_kzalloc(dev, sizeof(struct ili9341), GFP_KERNEL);
> +		if (!ili)
> +			return -ENOMEM;
> +
> +		ili->dbi = devm_kzalloc(dev, sizeof(struct mipi_dbi),
> +					GFP_KERNEL);
> +		if (!ili->dbi)
> +			return -ENOMEM;
> +
> +		ili->supplies[0].supply = "vci";
> +		ili->supplies[1].supply = "vddi";
> +		ili->supplies[2].supply = "vddi-led";
> +
> +		ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ili->supplies),
> +					      ili->supplies);
> +		if (ret < 0) {
> +			dev_err(dev, "failed to get regulators: %d\n", ret);
> +			return ret;
> +		}
> +
> +		ret = mipi_dbi_spi_init(spi, ili->dbi, dc);
> +		if (ret)
> +			return ret;
> +
> +		spi_set_drvdata(spi, ili);
> +
> +		ili->dev = dev;
> +		ili->reset_gpio = reset;
> +		/*
> +		 * Every new incarnation of this display must have a unique
> +		 * data entry for the system in this driver.
> +		 */
> +		ili->conf = of_device_get_match_data(dev);
> +		if (!ili->conf) {
> +			dev_err(dev, "missing device configuration\n");
> +			return -ENODEV;
> +		}
> +
> +		ili->max_spi_speed = ili->conf->max_spi_speed;
> +
> +		drm_panel_init(&ili->panel, dev, &ili9341_dpi_funcs,
> +			       DRM_MODE_CONNECTOR_DPI);
> +
> +		drm_panel_add(&ili->panel);
> +	}
> +
> +	return 0;
> +}
> +
> +static int ili9341_probe(struct spi_device *spi)
> +{
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +
> +	if (!strcmp(id->name, "sf-tc240t-9370-t"))
> +		return _ili9341_probe(spi, true);
> +	else if (!strcmp(id->name, "yx240qv29"))
> +		return _ili9341_probe(spi, false);
> +
> +	return -1;
> +}
> +
> +static int ili9341_remove(struct spi_device *spi)
> +{
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +	struct ili9341 *ili = spi_get_drvdata(spi);
> +	struct drm_device *drm = spi_get_drvdata(spi);
> +
> +	if (!strcmp(id->name, "sf-tc240t-9370-t")) {
> +		ili9341_dpi_power_off(ili);
> +		drm_panel_remove(&ili->panel);
> +	} else if (!strcmp(id->name, "yx240qv29")) {
> +		drm_dev_unplug(drm);
> +		drm_atomic_helper_shutdown(drm);
> +	}
> +	return 0;
> +}
> +
> +static void ili9341_shutdown(struct spi_device *spi)
> +{
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +
> +	if (!strcmp(id->name, "yx240qv29"))
> +		drm_atomic_helper_shutdown(spi_get_drvdata(spi));
> +}
> +
> +static const struct of_device_id ili9341_of_match[] = {
> +	{
> +		.compatible = "st,sf-tc240t-9370-t",
> +		.data = &ili9341_stm32f429_disco_data,
> +	},
> +	{
> +		/* porting from tiny/ili9341.c
> +		 * for original mipi dbi compitable
> +		 */
> +		.compatible = "adafruit,yx240qv29",
> +		.data = NULL,
> +	},
> +};
> +MODULE_DEVICE_TABLE(of, ili9341_of_match);
> +
> +static const struct spi_device_id ili9341_id[] = {
> +	{ "yx240qv29", 0 },
> +	{ "sf-tc240t-9370-t", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(spi, ili9341_id);
> +
> +static struct spi_driver ili9341_driver = {
> +	.probe = ili9341_probe,
> +	.remove = ili9341_remove,
> +	.shutdown = ili9341_shutdown,
> +	.id_table = ili9341_id,
> +	.driver = {
> +		.name = "panel-ilitek-ili9341",
> +		.of_match_table = ili9341_of_match,
> +	},
> +};
> +module_spi_driver(ili9341_driver);
> +
> +MODULE_AUTHOR("Dillon Min <dillon.minfei@gmail.com>");
> +MODULE_DESCRIPTION("ILI9341 LCD panel driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.7.4