2 * DRM driver for Sitronix ST7586 panels
4 * Copyright 2017 David Lechner <david@lechnology.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
12 #include <linux/delay.h>
13 #include <linux/dma-buf.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/module.h>
16 #include <linux/property.h>
17 #include <linux/spi/spi.h>
18 #include <video/mipi_display.h>
20 #include <drm/tinydrm/mipi-dbi.h>
21 #include <drm/tinydrm/tinydrm-helpers.h>
23 /* controller-specific commands */
24 #define ST7586_DISP_MODE_GRAY 0x38
25 #define ST7586_DISP_MODE_MONO 0x39
26 #define ST7586_ENABLE_DDRAM 0x3a
27 #define ST7586_SET_DISP_DUTY 0xb0
28 #define ST7586_SET_PART_DISP 0xb4
29 #define ST7586_SET_NLINE_INV 0xb5
30 #define ST7586_SET_VOP 0xc0
31 #define ST7586_SET_BIAS_SYSTEM 0xc3
32 #define ST7586_SET_BOOST_LEVEL 0xc4
33 #define ST7586_SET_VOP_OFFSET 0xc7
34 #define ST7586_ENABLE_ANALOG 0xd0
35 #define ST7586_AUTO_READ_CTRL 0xd7
36 #define ST7586_OTP_RW_CTRL 0xe0
37 #define ST7586_OTP_CTRL_OUT 0xe1
38 #define ST7586_OTP_READ 0xe3
40 #define ST7586_DISP_CTRL_MX BIT(6)
41 #define ST7586_DISP_CTRL_MY BIT(7)
44 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
45 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
46 * pixel using only 2 bits.
48 * | D7 | D6 | D5 || | || 2bpp |
49 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |
50 * +------+------+------++------+------++------+
51 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black
52 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray
53 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray
54 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white
57 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
59 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
60 struct drm_framebuffer *fb,
61 struct drm_clip_rect *clip)
63 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
67 buf = kmalloc(len, GFP_KERNEL);
71 tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
74 for (y = clip->y1; y < clip->y2; y++) {
75 for (x = clip->x1; x < clip->x2; x += 3) {
76 val = st7586_lookup[*src++ >> 6] << 5;
77 val |= st7586_lookup[*src++ >> 6] << 2;
78 val |= st7586_lookup[*src++ >> 6] >> 1;
86 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
87 struct drm_clip_rect *clip)
89 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
90 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
91 void *src = cma_obj->vaddr;
95 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
101 st7586_xrgb8888_to_gray332(dst, src, fb, clip);
104 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
110 static int st7586_fb_dirty(struct drm_framebuffer *fb,
111 struct drm_file *file_priv, unsigned int flags,
112 unsigned int color, struct drm_clip_rect *clips,
113 unsigned int num_clips)
115 struct tinydrm_device *tdev = fb->dev->dev_private;
116 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
117 struct drm_clip_rect clip;
121 mutex_lock(&tdev->dirty_lock);
126 /* fbdev can flush even when we're not interested */
127 if (tdev->pipe.plane.fb != fb)
130 tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
133 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
134 clip.x1 = rounddown(clip.x1, 3);
135 clip.x2 = roundup(clip.x2, 3);
137 DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
138 clip.x1, clip.x2, clip.y1, clip.y2);
140 ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
144 /* Pixels are packed 3 per byte */
148 mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
149 (start >> 8) & 0xFF, start & 0xFF,
150 (end >> 8) & 0xFF, (end - 1) & 0xFF);
151 mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
152 (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
153 (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
155 ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
157 (end - start) * (clip.y2 - clip.y1));
160 mutex_unlock(&tdev->dirty_lock);
163 dev_err_once(fb->dev->dev, "Failed to update display %d\n",
169 static const struct drm_framebuffer_funcs st7586_fb_funcs = {
170 .destroy = drm_fb_cma_destroy,
171 .create_handle = drm_fb_cma_create_handle,
172 .dirty = st7586_fb_dirty,
175 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
176 struct drm_crtc_state *crtc_state)
178 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
179 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
180 struct drm_framebuffer *fb = pipe->plane.fb;
181 struct device *dev = tdev->drm->dev;
187 mipi_dbi_hw_reset(mipi);
188 ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
190 dev_err(dev, "Error sending command %d\n", ret);
194 mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
198 mipi_dbi_command(mipi, ST7586_OTP_READ);
202 mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
203 mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
204 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
208 mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
209 mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
210 mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
211 mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
212 mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
213 mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
214 mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
215 mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
217 switch (mipi->rotation) {
222 addr_mode = ST7586_DISP_CTRL_MY;
225 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
228 addr_mode = ST7586_DISP_CTRL_MX;
231 mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
233 mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
234 mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
235 mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
236 mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
240 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
242 mipi->enabled = true;
245 fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
248 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
250 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
251 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
258 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
259 mipi->enabled = false;
262 static const u32 st7586_formats[] = {
266 static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
267 const struct drm_simple_display_pipe_funcs *pipe_funcs,
268 struct drm_driver *driver, const struct drm_display_mode *mode,
269 unsigned int rotation)
271 size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
272 struct tinydrm_device *tdev = &mipi->tinydrm;
275 mutex_init(&mipi->cmdlock);
277 mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
281 ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
285 ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
286 DRM_MODE_CONNECTOR_VIRTUAL,
288 ARRAY_SIZE(st7586_formats),
293 tdev->drm->mode_config.preferred_depth = 32;
294 mipi->rotation = rotation;
296 drm_mode_config_reset(tdev->drm);
298 DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
299 tdev->drm->mode_config.preferred_depth, rotation);
304 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
305 .enable = st7586_pipe_enable,
306 .disable = st7586_pipe_disable,
307 .update = tinydrm_display_pipe_update,
308 .prepare_fb = tinydrm_display_pipe_prepare_fb,
311 static const struct drm_display_mode st7586_mode = {
312 TINYDRM_MODE(178, 128, 37, 27),
315 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
317 static struct drm_driver st7586_driver = {
318 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
320 .fops = &st7586_fops,
321 TINYDRM_GEM_DRIVER_OPS,
322 .lastclose = tinydrm_lastclose,
323 .debugfs_init = mipi_dbi_debugfs_init,
325 .desc = "Sitronix ST7586",
331 static const struct of_device_id st7586_of_match[] = {
332 { .compatible = "lego,ev3-lcd" },
335 MODULE_DEVICE_TABLE(of, st7586_of_match);
337 static const struct spi_device_id st7586_id[] = {
341 MODULE_DEVICE_TABLE(spi, st7586_id);
343 static int st7586_probe(struct spi_device *spi)
345 struct device *dev = &spi->dev;
346 struct tinydrm_device *tdev;
347 struct mipi_dbi *mipi;
348 struct gpio_desc *a0;
352 mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
356 mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
357 if (IS_ERR(mipi->reset)) {
358 dev_err(dev, "Failed to get gpio 'reset'\n");
359 return PTR_ERR(mipi->reset);
362 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
364 dev_err(dev, "Failed to get gpio 'a0'\n");
368 device_property_read_u32(dev, "rotation", &rotation);
370 ret = mipi_dbi_spi_init(spi, mipi, a0);
374 /* Cannot read from this controller via SPI */
375 mipi->read_commands = NULL;
378 * we are using 8-bit data, so we are not actually swapping anything,
379 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
380 * right thing and not use 16-bit transfers (which results in swapped
381 * bytes on little-endian systems and causes out of order data to be
382 * sent to the display).
384 mipi->swap_bytes = true;
386 ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
387 &st7586_mode, rotation);
391 tdev = &mipi->tinydrm;
393 ret = devm_tinydrm_register(tdev);
397 spi_set_drvdata(spi, mipi);
399 DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
400 tdev->drm->driver->name, dev_name(dev),
401 spi->max_speed_hz / 1000000,
402 tdev->drm->primary->index);
407 static void st7586_shutdown(struct spi_device *spi)
409 struct mipi_dbi *mipi = spi_get_drvdata(spi);
411 tinydrm_shutdown(&mipi->tinydrm);
414 static struct spi_driver st7586_spi_driver = {
417 .owner = THIS_MODULE,
418 .of_match_table = st7586_of_match,
420 .id_table = st7586_id,
421 .probe = st7586_probe,
422 .shutdown = st7586_shutdown,
424 module_spi_driver(st7586_spi_driver);
426 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
427 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
428 MODULE_LICENSE("GPL");