Den 02.08.2017 00.11, skrev David Lechner:

LEGO MINDSTORMS EV3 has an LCD with a ST7586 controller. This adds a new
module for the ST7586 controller with parameters for the EV3 LCD display.

Signed-off-by: David Lechner <david@lechnology.com>
---
  .../devicetree/bindings/display/st7586.txt         |  26 +
  drivers/gpu/drm/tinydrm/Kconfig                    |  10 +
  drivers/gpu/drm/tinydrm/Makefile                   |   1 +
  drivers/gpu/drm/tinydrm/st7586.c                   | 579 +++++++++++++++++++++
  include/drm/tinydrm/st7586.h                       |  34 ++

Please add a MAINTAINERS entry.
That way you'll be notified on changes.

This doesn't match the ST7586 datasheet I have, the pins are called
IF[3:1] and the values are different.

Please use tinydrm_xrgb8888_to_gray8().

+
+static int st7586_mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb,

You can shorten your st7586_mipi_dbi_* to just st7586_*

+				    struct drm_clip_rect *clip)
+{
+	struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+	struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
+	struct drm_format_name_buf format_name;
+	void *src = cma_obj->vaddr;
+	int ret = 0;
+
+	if (import_attach) {
+		ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
+					       DMA_FROM_DEVICE);
+		if (ret)
+			return ret;
+	}
+
+	switch (fb->format->format) {
+	case DRM_FORMAT_RGB565:
+		st7586_from_rgb565(dst, src, fb, clip);
+		break;
+	case DRM_FORMAT_XRGB8888:
+		st7586_from_xrgb8888(dst, src, fb, clip);
+		break;
+	default:
+		dev_err_once(fb->dev->dev, "Format is not supported: %s\n",
+			     drm_get_format_name(fb->format->format,
+						 &format_name));
+		ret = -EINVAL;
+		break;
+	}
+
+	if (import_attach)
+		ret = dma_buf_end_cpu_access(import_attach->dmabuf,
+					     DMA_FROM_DEVICE);
+	return ret;
+}
+
+static int st7586_mipi_dbi_fb_dirty(struct drm_framebuffer *fb,
+				    struct drm_file *file_priv,
+				    unsigned int flags, unsigned int color,
+				    struct drm_clip_rect *clips,
+				    unsigned int num_clips)
+{
+	struct tinydrm_device *tdev = fb->dev->dev_private;
+	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+	struct drm_clip_rect clip;
+	int ret = 0;
+
+	mutex_lock(&tdev->dirty_lock);
+
+	if (!mipi->enabled)
+		goto out_unlock;
+
+	/* fbdev can flush even when we're not interested */
+	if (tdev->pipe.plane.fb != fb)
+		goto out_unlock;
+
+	tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
+			    fb->height);
+
+	DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
+		  clip.x1, clip.x2, clip.y1, clip.y2);
+
+	ret = st7586_mipi_dbi_buf_copy(mipi->tx_buf, fb, &clip);
+	if (ret)
+		goto out_unlock;
+
+	/* NB: st7586_mipi_dbi_buf_copy() modifies clip */
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
+			 (clip.x1 >> 8) & 0xFF, clip.x1 & 0xFF,
+			 (clip.x2 >> 8) & 0xFF, (clip.x2 - 1) & 0xFF);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
+			 (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
+			 (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
+
+	ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
+				   (u8 *)mipi->tx_buf,
+				   (clip.x2 - clip.x1) * (clip.y2 - clip.y1));
+
+out_unlock:
+	mutex_unlock(&tdev->dirty_lock);
+
+	if (ret)
+		dev_err_once(fb->dev->dev, "Failed to update display %d\n",
+			     ret);
+
+	return ret;
+}
+
+static const struct drm_framebuffer_funcs st7586_mipi_dbi_fb_funcs = {
+	.destroy	= drm_fb_cma_destroy,
+	.create_handle	= drm_fb_cma_create_handle,
+	.dirty		= st7586_mipi_dbi_fb_dirty,
+};
+
+void st7586_mipi_dbi_pipe_enable(struct drm_simple_display_pipe *pipe,
+				 struct drm_crtc_state *crtc_state)
+{
+	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+	struct drm_framebuffer *fb = pipe->plane.fb;
+
+	DRM_DEBUG_KMS("\n");
+

You should use this function to enable the regulator and init the
controller. Don't look at mi0283qt it should have been fixed.

+	mipi->enabled = true;
+	if (fb)

I don't think it's possible to enable the pipe without a framebuffer,
but I wasn't able find out. drm is complex...

+		fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
+
+	tinydrm_enable_backlight(mipi->backlight);
+}
+
+static void st7586_mipi_dbi_blank(struct mipi_dbi *mipi)
+{
+	struct drm_device *drm = mipi->tinydrm.drm;
+	u16 height = drm->mode_config.min_height;
+	u16 width = (drm->mode_config.min_width + 2) / 3;
+	size_t len = width * height;
+
+	memset(mipi->tx_buf, 0, len);
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS, 0, 0,
+			 (width >> 8) & 0xFF, (width - 1) & 0xFF);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS, 0, 0,
+			 (height >> 8) & 0xFF, (height - 1) & 0xFF);
+	mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
+			     (u8 *)mipi->tx_buf, len);
+}
+
+static void st7586_mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+
+	DRM_DEBUG_KMS("\n");
+
+	mipi->enabled = false;
+
+	if (mipi->backlight)
+		tinydrm_disable_backlight(mipi->backlight);
+	else
+		st7586_mipi_dbi_blank(mipi);

And disable the regulator here.

+}
+
+static const u32 st7586_mipi_dbi_formats[] = {
+	DRM_FORMAT_RGB565,
+	DRM_FORMAT_XRGB8888,

Why 2 emulation formats?
I chose DRM_FORMAT_XRGB8888 since I expected everything to support it.
Please use only that.

+};
+
+static int st7586_mipi_dbi_init(struct device *dev, struct mipi_dbi *mipi,
+		const struct drm_simple_display_pipe_funcs *pipe_funcs,
+		struct drm_driver *driver, const struct drm_display_mode *mode,
+		unsigned int rotation)
+{
+	size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
+	struct tinydrm_device *tdev = &mipi->tinydrm;
+	int ret;
+
+	if (!mipi->command)
+		return -EINVAL;

You know this is set after calling mipi_dbi_spi_init(), so you don't 
have to check.

+
+	mutex_init(&mipi->cmdlock);
+
+	mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
+	if (!mipi->tx_buf)
+		return -ENOMEM;
+
+	ret = devm_tinydrm_init(dev, tdev, &st7586_mipi_dbi_fb_funcs, driver);
+	if (ret)
+		return ret;
+
+	ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
+					DRM_MODE_CONNECTOR_VIRTUAL,
+					st7586_mipi_dbi_formats,
+					ARRAY_SIZE(st7586_mipi_dbi_formats),
+					mode, rotation);
+	if (ret)
+		return ret;
+
+	tdev->drm->mode_config.preferred_depth = 16;
+	mipi->rotation = rotation;
+
+	drm_mode_config_reset(tdev->drm);
+
+	DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
+		      tdev->drm->mode_config.preferred_depth, rotation);
+
+	return 0;
+}
+
+static int st7586_init(struct mipi_dbi *mipi)
+{
+	struct tinydrm_device *tdev = &mipi->tinydrm;
+	struct device *dev = tdev->drm->dev;
+	u8 addr_mode;
+	int ret;
+
+	DRM_DEBUG_KMS("\n");
+
+	ret = regulator_enable(mipi->regulator);
+	if (ret) {
+		dev_err(dev, "Failed to enable regulator %d\n", ret);
+		return ret;
+	}
+
+	/* Avoid flicker by skipping setup if the bootloader has done it */
+	if (mipi_dbi_display_is_on(mipi))

Looking at the datasheet it seems that it's not possible to read from
the controller via SPI?

+		return 0;
+
+	mipi_dbi_hw_reset(mipi);
+	ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
+	if (ret) {
+		dev_err(dev, "Error sending command %d\n", ret);
+		regulator_disable(mipi->regulator);
+		return ret;
+	}
+
+	mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
+
+	msleep(10);
+
+	mipi_dbi_command(mipi, ST7586_OTP_READ);
+
+	msleep(20);
+
+	mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
+	mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
+
+	msleep(50);
+
+	mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
+	mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
+	mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
+	mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
+	mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
+	mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
+	mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
+	mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
+
+	switch (mipi->rotation) {
+	default:
+		addr_mode = 0x00;
+		break;
+	case 90:
+		addr_mode = ST7586_DISP_CTRL_MY;
+		break;
+	case 180:
+		addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
+		break;
+	case 270:
+		addr_mode = ST7586_DISP_CTRL_MX;
+		break;
+	}
+	mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+
+	mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
+	mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
+	mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
+	mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
+
+	msleep(100);
+
+	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
+
+	return 0;
+}
+
+static void st7586_fini(void *data)
+{
+	struct mipi_dbi *mipi = data;
+
+	DRM_DEBUG_KMS("\n");
+	regulator_disable(mipi->regulator);
+}
+
+static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
+	.enable = st7586_mipi_dbi_pipe_enable,
+	.disable = st7586_mipi_dbi_pipe_disable,
+	.update = tinydrm_display_pipe_update,
+	.prepare_fb = tinydrm_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode st7586_mode = {
+	TINYDRM_MODE(178, 128, 37, 27),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
+
+static struct drm_driver st7586_driver = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+				  DRIVER_ATOMIC,
+	.fops			= &st7586_fops,
+	TINYDRM_GEM_DRIVER_OPS,
+	.lastclose		= tinydrm_lastclose,
+	.debugfs_init		= mipi_dbi_debugfs_init,
+	.name			= "st7586",
+	.desc			= "Sitronix ST7586",
+	.date			= "20170801",
+	.major			= 1,
+	.minor			= 0,
+};
+
+static const struct of_device_id st7586_of_match[] = {
+	{ .compatible = "lego,ev3-lcd" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st7586_of_match);
+
+static const struct spi_device_id st7586_id[] = {
+	{ "ev3-lcd", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(spi, st7586_id);
+
+static int st7586_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct tinydrm_device *tdev;
+	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)) {
+		dev_err(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)) {
+		dev_err(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 = tinydrm_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;

Since you are using mipi_dbi_debugfs_init and the controller can't be
read, disable reading:

mipi->read_commands = NULL;

+
+	/*
+	 * we are using 8-bit data, so we are not actually swapping anything,
+	 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
+	 * right thing and not use 16-bit transfers (which results in swapped
+	 * bytes on little-endian systems and causes out of order data to be
+	 * sent to the display).
+	 */
+	mipi->swap_bytes = true;
+
+	ret = st7586_mipi_dbi_init(&spi->dev, mipi, &st7586_pipe_funcs,
+				   &st7586_driver, &st7586_mode, rotation);
+	if (ret)
+		return ret;
+
+	ret = st7586_init(mipi);

This isn't necessary when you use .enable/.disable to control power/init,
and you can drop the devm_add_action.

+	if (ret)
+		return ret;
+
+	/* use devres to fini after drm unregister (drv->remove is before) */
+	ret = devm_add_action(dev, st7586_fini, mipi);
+	if (ret) {
+		st7586_fini(mipi);
+		return ret;
+	}
+
+	tdev = &mipi->tinydrm;
+
+	ret = devm_tinydrm_register(tdev);
+	if (ret)
+		return ret;
+
+	spi_set_drvdata(spi, mipi);
+
+	DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
+			 tdev->drm->driver->name, dev_name(dev),
+			 spi->max_speed_hz / 1000000,
+			 tdev->drm->primary->index);
+
+	return 0;
+}
+
+static void st7586_shutdown(struct spi_device *spi)
+{
+	struct mipi_dbi *mipi = spi_get_drvdata(spi);
+
+	tinydrm_shutdown(&mipi->tinydrm);
+}
+
+static int __maybe_unused st7586_pm_suspend(struct device *dev)
+{
+	struct mipi_dbi *mipi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = tinydrm_suspend(&mipi->tinydrm);
+	if (ret)
+		return ret;
+
+	st7586_fini(mipi);
+

With .enable/.disable controlling power, tinydrm_suspend() is enough.

+	return 0;
+}
+
+static int __maybe_unused st7586_pm_resume(struct device *dev)
+{
+	struct mipi_dbi *mipi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = st7586_init(mipi);
+	if (ret)
+		return ret;
+

Same goes here.

Please put this in drivers/drm/tinydrm, or you can even put the defines
in the driver if you want, it's quite short.
ili9341.h shouldn't have ended up in include/drm/tinydrm.

Noralf.