tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * DRM driver for Sitronix ST7586 panels
3 *
4 * Copyright 2017 David Lechner <david@lechnology.com>
5 *
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.
10 */
11
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>
19
20#include <drm/drm_gem_framebuffer_helper.h>
21#include <drm/tinydrm/mipi-dbi.h>
22#include <drm/tinydrm/tinydrm-helpers.h>
23
24/* controller-specific commands */
25#define ST7586_DISP_MODE_GRAY 0x38
26#define ST7586_DISP_MODE_MONO 0x39
27#define ST7586_ENABLE_DDRAM 0x3a
28#define ST7586_SET_DISP_DUTY 0xb0
29#define ST7586_SET_PART_DISP 0xb4
30#define ST7586_SET_NLINE_INV 0xb5
31#define ST7586_SET_VOP 0xc0
32#define ST7586_SET_BIAS_SYSTEM 0xc3
33#define ST7586_SET_BOOST_LEVEL 0xc4
34#define ST7586_SET_VOP_OFFSET 0xc7
35#define ST7586_ENABLE_ANALOG 0xd0
36#define ST7586_AUTO_READ_CTRL 0xd7
37#define ST7586_OTP_RW_CTRL 0xe0
38#define ST7586_OTP_CTRL_OUT 0xe1
39#define ST7586_OTP_READ 0xe3
40
41#define ST7586_DISP_CTRL_MX BIT(6)
42#define ST7586_DISP_CTRL_MY BIT(7)
43
44/*
45 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
46 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
47 * pixel using only 2 bits.
48 *
49 * | D7 | D6 | D5 || | || 2bpp |
50 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |
51 * +------+------+------++------+------++------+
52 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black
53 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray
54 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray
55 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white
56 */
57
58static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
59
60static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
61 struct drm_framebuffer *fb,
62 struct drm_clip_rect *clip)
63{
64 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
65 unsigned int x, y;
66 u8 *src, *buf, val;
67
68 buf = kmalloc(len, GFP_KERNEL);
69 if (!buf)
70 return;
71
72 tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
73 src = buf;
74
75 for (y = clip->y1; y < clip->y2; y++) {
76 for (x = clip->x1; x < clip->x2; x += 3) {
77 val = st7586_lookup[*src++ >> 6] << 5;
78 val |= st7586_lookup[*src++ >> 6] << 2;
79 val |= st7586_lookup[*src++ >> 6] >> 1;
80 *dst++ = val;
81 }
82 }
83
84 kfree(buf);
85}
86
87static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
88 struct drm_clip_rect *clip)
89{
90 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
91 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
92 void *src = cma_obj->vaddr;
93 int ret = 0;
94
95 if (import_attach) {
96 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
97 DMA_FROM_DEVICE);
98 if (ret)
99 return ret;
100 }
101
102 st7586_xrgb8888_to_gray332(dst, src, fb, clip);
103
104 if (import_attach)
105 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
106 DMA_FROM_DEVICE);
107
108 return ret;
109}
110
111static int st7586_fb_dirty(struct drm_framebuffer *fb,
112 struct drm_file *file_priv, unsigned int flags,
113 unsigned int color, struct drm_clip_rect *clips,
114 unsigned int num_clips)
115{
116 struct tinydrm_device *tdev = fb->dev->dev_private;
117 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
118 struct drm_clip_rect clip;
119 int start, end;
120 int ret = 0;
121
122 mutex_lock(&tdev->dirty_lock);
123
124 if (!mipi->enabled)
125 goto out_unlock;
126
127 /* fbdev can flush even when we're not interested */
128 if (tdev->pipe.plane.fb != fb)
129 goto out_unlock;
130
131 tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
132 fb->height);
133
134 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
135 clip.x1 = rounddown(clip.x1, 3);
136 clip.x2 = roundup(clip.x2, 3);
137
138 DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
139 clip.x1, clip.x2, clip.y1, clip.y2);
140
141 ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
142 if (ret)
143 goto out_unlock;
144
145 /* Pixels are packed 3 per byte */
146 start = clip.x1 / 3;
147 end = clip.x2 / 3;
148
149 mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
150 (start >> 8) & 0xFF, start & 0xFF,
151 (end >> 8) & 0xFF, (end - 1) & 0xFF);
152 mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
153 (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
154 (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
155
156 ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
157 (u8 *)mipi->tx_buf,
158 (end - start) * (clip.y2 - clip.y1));
159
160out_unlock:
161 mutex_unlock(&tdev->dirty_lock);
162
163 if (ret)
164 dev_err_once(fb->dev->dev, "Failed to update display %d\n",
165 ret);
166
167 return ret;
168}
169
170static const struct drm_framebuffer_funcs st7586_fb_funcs = {
171 .destroy = drm_gem_fb_destroy,
172 .create_handle = drm_gem_fb_create_handle,
173 .dirty = st7586_fb_dirty,
174};
175
176static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
177 struct drm_crtc_state *crtc_state)
178{
179 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
180 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
181 struct drm_framebuffer *fb = pipe->plane.fb;
182 struct device *dev = tdev->drm->dev;
183 int ret;
184 u8 addr_mode;
185
186 DRM_DEBUG_KMS("\n");
187
188 mipi_dbi_hw_reset(mipi);
189 ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
190 if (ret) {
191 DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
192 return;
193 }
194
195 mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
196
197 msleep(10);
198
199 mipi_dbi_command(mipi, ST7586_OTP_READ);
200
201 msleep(20);
202
203 mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
204 mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
205 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
206
207 msleep(50);
208
209 mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
210 mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
211 mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
212 mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
213 mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
214 mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
215 mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
216 mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
217
218 switch (mipi->rotation) {
219 default:
220 addr_mode = 0x00;
221 break;
222 case 90:
223 addr_mode = ST7586_DISP_CTRL_MY;
224 break;
225 case 180:
226 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
227 break;
228 case 270:
229 addr_mode = ST7586_DISP_CTRL_MX;
230 break;
231 }
232 mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
233
234 mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
235 mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
236 mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
237 mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
238
239 msleep(100);
240
241 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
242
243 mipi->enabled = true;
244
245 if (fb)
246 fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
247}
248
249static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
250{
251 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
252 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
253
254 DRM_DEBUG_KMS("\n");
255
256 if (!mipi->enabled)
257 return;
258
259 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
260 mipi->enabled = false;
261}
262
263static const u32 st7586_formats[] = {
264 DRM_FORMAT_XRGB8888,
265};
266
267static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
268 const struct drm_simple_display_pipe_funcs *pipe_funcs,
269 struct drm_driver *driver, const struct drm_display_mode *mode,
270 unsigned int rotation)
271{
272 size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
273 struct tinydrm_device *tdev = &mipi->tinydrm;
274 int ret;
275
276 mutex_init(&mipi->cmdlock);
277
278 mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
279 if (!mipi->tx_buf)
280 return -ENOMEM;
281
282 ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
283 if (ret)
284 return ret;
285
286 ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
287 DRM_MODE_CONNECTOR_VIRTUAL,
288 st7586_formats,
289 ARRAY_SIZE(st7586_formats),
290 mode, rotation);
291 if (ret)
292 return ret;
293
294 tdev->drm->mode_config.preferred_depth = 32;
295 mipi->rotation = rotation;
296
297 drm_mode_config_reset(tdev->drm);
298
299 DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
300 tdev->drm->mode_config.preferred_depth, rotation);
301
302 return 0;
303}
304
305static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
306 .enable = st7586_pipe_enable,
307 .disable = st7586_pipe_disable,
308 .update = tinydrm_display_pipe_update,
309 .prepare_fb = tinydrm_display_pipe_prepare_fb,
310};
311
312static const struct drm_display_mode st7586_mode = {
313 TINYDRM_MODE(178, 128, 37, 27),
314};
315
316DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
317
318static struct drm_driver st7586_driver = {
319 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
320 DRIVER_ATOMIC,
321 .fops = &st7586_fops,
322 TINYDRM_GEM_DRIVER_OPS,
323 .lastclose = tinydrm_lastclose,
324 .debugfs_init = mipi_dbi_debugfs_init,
325 .name = "st7586",
326 .desc = "Sitronix ST7586",
327 .date = "20170801",
328 .major = 1,
329 .minor = 0,
330};
331
332static const struct of_device_id st7586_of_match[] = {
333 { .compatible = "lego,ev3-lcd" },
334 {},
335};
336MODULE_DEVICE_TABLE(of, st7586_of_match);
337
338static const struct spi_device_id st7586_id[] = {
339 { "ev3-lcd", 0 },
340 { },
341};
342MODULE_DEVICE_TABLE(spi, st7586_id);
343
344static int st7586_probe(struct spi_device *spi)
345{
346 struct device *dev = &spi->dev;
347 struct mipi_dbi *mipi;
348 struct gpio_desc *a0;
349 u32 rotation = 0;
350 int ret;
351
352 mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
353 if (!mipi)
354 return -ENOMEM;
355
356 mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
357 if (IS_ERR(mipi->reset)) {
358 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
359 return PTR_ERR(mipi->reset);
360 }
361
362 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
363 if (IS_ERR(a0)) {
364 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
365 return PTR_ERR(a0);
366 }
367
368 device_property_read_u32(dev, "rotation", &rotation);
369
370 ret = mipi_dbi_spi_init(spi, mipi, a0);
371 if (ret)
372 return ret;
373
374 /* Cannot read from this controller via SPI */
375 mipi->read_commands = NULL;
376
377 /*
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).
383 */
384 mipi->swap_bytes = true;
385
386 ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
387 &st7586_mode, rotation);
388 if (ret)
389 return ret;
390
391 spi_set_drvdata(spi, mipi);
392
393 return devm_tinydrm_register(&mipi->tinydrm);
394}
395
396static void st7586_shutdown(struct spi_device *spi)
397{
398 struct mipi_dbi *mipi = spi_get_drvdata(spi);
399
400 tinydrm_shutdown(&mipi->tinydrm);
401}
402
403static struct spi_driver st7586_spi_driver = {
404 .driver = {
405 .name = "st7586",
406 .owner = THIS_MODULE,
407 .of_match_table = st7586_of_match,
408 },
409 .id_table = st7586_id,
410 .probe = st7586_probe,
411 .shutdown = st7586_shutdown,
412};
413module_spi_driver(st7586_spi_driver);
414
415MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
416MODULE_AUTHOR("David Lechner <david@lechnology.com>");
417MODULE_LICENSE("GPL");