1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * DRM driver for Sitronix ST7586 panels
4 *
5 * Copyright 2017 David Lechner <david@lechnology.com>
6 */
7
8 #include <linux/delay.h>
9 #include <linux/gpio/consumer.h>
10 #include <linux/module.h>
11 #include <linux/property.h>
12 #include <linux/spi/spi.h>
13 #include <video/mipi_display.h>
14
15 #include <drm/clients/drm_client_setup.h>
16 #include <drm/drm_atomic.h>
17 #include <drm/drm_atomic_helper.h>
18 #include <drm/drm_damage_helper.h>
19 #include <drm/drm_drv.h>
20 #include <drm/drm_fb_dma_helper.h>
21 #include <drm/drm_fbdev_dma.h>
22 #include <drm/drm_format_helper.h>
23 #include <drm/drm_framebuffer.h>
24 #include <drm/drm_gem_atomic_helper.h>
25 #include <drm/drm_gem_dma_helper.h>
26 #include <drm/drm_gem_framebuffer_helper.h>
27 #include <drm/drm_managed.h>
28 #include <drm/drm_mipi_dbi.h>
29 #include <drm/drm_print.h>
30 #include <drm/drm_rect.h>
31
32 /* controller-specific commands */
33 #define ST7586_DISP_MODE_GRAY 0x38
34 #define ST7586_DISP_MODE_MONO 0x39
35 #define ST7586_ENABLE_DDRAM 0x3a
36 #define ST7586_SET_DISP_DUTY 0xb0
37 #define ST7586_SET_PART_DISP 0xb4
38 #define ST7586_SET_NLINE_INV 0xb5
39 #define ST7586_SET_VOP 0xc0
40 #define ST7586_SET_BIAS_SYSTEM 0xc3
41 #define ST7586_SET_BOOST_LEVEL 0xc4
42 #define ST7586_SET_VOP_OFFSET 0xc7
43 #define ST7586_ENABLE_ANALOG 0xd0
44 #define ST7586_AUTO_READ_CTRL 0xd7
45 #define ST7586_OTP_RW_CTRL 0xe0
46 #define ST7586_OTP_CTRL_OUT 0xe1
47 #define ST7586_OTP_READ 0xe3
48
49 #define ST7586_DISP_CTRL_MX BIT(6)
50 #define ST7586_DISP_CTRL_MY BIT(7)
51
52 struct st7586_device {
53 struct mipi_dbi_dev dbidev;
54
55 struct drm_plane plane;
56 struct drm_crtc crtc;
57 struct drm_encoder encoder;
58 struct drm_connector connector;
59 };
60
to_st7586_device(struct drm_device * dev)61 static struct st7586_device *to_st7586_device(struct drm_device *dev)
62 {
63 return container_of(drm_to_mipi_dbi_dev(dev), struct st7586_device, dbidev);
64 }
65
66 /*
67 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
68 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
69 * pixel using only 2 bits.
70 *
71 * | D7 | D6 | D5 || | || 2bpp |
72 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |
73 * +------+------+------++------+------++------+
74 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black
75 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray
76 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray
77 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white
78 */
79
80 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
81
st7586_xrgb8888_to_gray332(u8 * dst,void * vaddr,struct drm_framebuffer * fb,struct drm_rect * clip,struct drm_format_conv_state * fmtcnv_state)82 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
83 struct drm_framebuffer *fb,
84 struct drm_rect *clip,
85 struct drm_format_conv_state *fmtcnv_state)
86 {
87 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
88 unsigned int x, y;
89 u8 *src, *buf, val;
90 struct iosys_map dst_map, vmap;
91
92 buf = kmalloc(len, GFP_KERNEL);
93 if (!buf)
94 return;
95
96 iosys_map_set_vaddr(&dst_map, buf);
97 iosys_map_set_vaddr(&vmap, vaddr);
98 drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip, fmtcnv_state);
99 src = buf;
100
101 for (y = clip->y1; y < clip->y2; y++) {
102 for (x = clip->x1; x < clip->x2; x += 3) {
103 val = st7586_lookup[*src++ >> 6] << 5;
104 val |= st7586_lookup[*src++ >> 6] << 2;
105 val |= st7586_lookup[*src++ >> 6] >> 1;
106 *dst++ = val;
107 }
108 }
109
110 kfree(buf);
111 }
112
st7586_buf_copy(void * dst,struct iosys_map * src,struct drm_framebuffer * fb,struct drm_rect * clip,struct drm_format_conv_state * fmtcnv_state)113 static int st7586_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,
114 struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)
115 {
116 int ret;
117
118 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
119 if (ret)
120 return ret;
121
122 st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip, fmtcnv_state);
123
124 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
125
126 return 0;
127 }
128
st7586_fb_dirty(struct iosys_map * src,struct drm_framebuffer * fb,struct drm_rect * rect,struct drm_format_conv_state * fmtcnv_state)129 static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
130 struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
131 {
132 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
133 struct mipi_dbi *dbi = &dbidev->dbi;
134 int start, end, ret = 0;
135
136 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
137 rect->x1 = rounddown(rect->x1, 3);
138 rect->x2 = roundup(rect->x2, 3);
139
140 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
141
142 ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);
143 if (ret)
144 goto err_msg;
145
146 /* Pixels are packed 3 per byte */
147 start = rect->x1 / 3;
148 end = rect->x2 / 3;
149
150 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
151 (start >> 8) & 0xFF, start & 0xFF,
152 (end >> 8) & 0xFF, (end - 1) & 0xFF);
153 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
154 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
155 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
156
157 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
158 (u8 *)dbidev->tx_buf,
159 (end - start) * (rect->y2 - rect->y1));
160 err_msg:
161 if (ret)
162 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
163 }
164
165 static const u32 st7586_plane_formats[] = {
166 DRM_FORMAT_XRGB8888,
167 };
168
169 static const u64 st7586_plane_format_modifiers[] = {
170 DRM_MIPI_DBI_PLANE_FORMAT_MODIFIERS,
171 };
172
st7586_plane_helper_atomic_update(struct drm_plane * plane,struct drm_atomic_state * state)173 static void st7586_plane_helper_atomic_update(struct drm_plane *plane,
174 struct drm_atomic_state *state)
175 {
176 struct drm_plane_state *plane_state = plane->state;
177 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
178 struct drm_framebuffer *fb = plane_state->fb;
179 struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
180 struct drm_rect rect;
181 int idx;
182
183 if (!fb)
184 return;
185
186 if (!drm_dev_enter(plane->dev, &idx))
187 return;
188
189 if (drm_atomic_helper_damage_merged(old_plane_state, plane_state, &rect))
190 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
191 &shadow_plane_state->fmtcnv_state);
192
193 drm_dev_exit(idx);
194 }
195
196 static const struct drm_plane_helper_funcs st7586_plane_helper_funcs = {
197 DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
198 .atomic_check = drm_mipi_dbi_plane_helper_atomic_check,
199 .atomic_update = st7586_plane_helper_atomic_update
200 };
201
202 static const struct drm_plane_funcs st7586_plane_funcs = {
203 DRM_MIPI_DBI_PLANE_FUNCS,
204 .destroy = drm_plane_cleanup,
205 };
206
st7586_crtc_helper_atomic_enable(struct drm_crtc * crtc,struct drm_atomic_state * state)207 static void st7586_crtc_helper_atomic_enable(struct drm_crtc *crtc,
208 struct drm_atomic_state *state)
209 {
210 struct drm_device *drm = crtc->dev;
211 struct st7586_device *st7586 = to_st7586_device(drm);
212 struct mipi_dbi_dev *dbidev = &st7586->dbidev;
213 struct mipi_dbi *dbi = &dbidev->dbi;
214 int idx, ret;
215 u8 addr_mode;
216
217 if (!drm_dev_enter(drm, &idx))
218 return;
219
220 DRM_DEBUG_KMS("\n");
221
222 ret = mipi_dbi_poweron_reset(dbidev);
223 if (ret)
224 goto out_exit;
225
226 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
227 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
228
229 msleep(10);
230
231 mipi_dbi_command(dbi, ST7586_OTP_READ);
232
233 msleep(20);
234
235 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
236 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
237 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
238
239 msleep(50);
240
241 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
242 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
243 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
244 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
245 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
246 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
247 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
248 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
249
250 switch (dbidev->rotation) {
251 default:
252 addr_mode = 0x00;
253 break;
254 case 90:
255 addr_mode = ST7586_DISP_CTRL_MY;
256 break;
257 case 180:
258 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
259 break;
260 case 270:
261 addr_mode = ST7586_DISP_CTRL_MX;
262 break;
263 }
264 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
265
266 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
267 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
268 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
269 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
270
271 msleep(100);
272
273 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
274 out_exit:
275 drm_dev_exit(idx);
276 }
277
st7586_crtc_helper_atomic_disable(struct drm_crtc * crtc,struct drm_atomic_state * state)278 static void st7586_crtc_helper_atomic_disable(struct drm_crtc *crtc,
279 struct drm_atomic_state *state)
280 {
281 struct drm_device *drm = crtc->dev;
282 struct st7586_device *st7586 = to_st7586_device(drm);
283 struct mipi_dbi_dev *dbidev = &st7586->dbidev;
284
285 /*
286 * This callback is not protected by drm_dev_enter/exit since we want to
287 * turn off the display on regular driver unload. It's highly unlikely
288 * that the underlying SPI controller is gone should this be called after
289 * unplug.
290 */
291
292 DRM_DEBUG_KMS("\n");
293
294 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
295 }
296
297 static const struct drm_crtc_helper_funcs st7586_crtc_helper_funcs = {
298 .mode_valid = drm_mipi_dbi_crtc_helper_mode_valid,
299 .atomic_check = drm_mipi_dbi_crtc_helper_atomic_check,
300 .atomic_enable = st7586_crtc_helper_atomic_enable,
301 .atomic_disable = st7586_crtc_helper_atomic_disable,
302 };
303
304 static const struct drm_crtc_funcs st7586_crtc_funcs = {
305 DRM_MIPI_DBI_CRTC_FUNCS,
306 .destroy = drm_crtc_cleanup,
307 };
308
309 static const struct drm_encoder_funcs st7586_encoder_funcs = {
310 .destroy = drm_encoder_cleanup,
311 };
312
313 static const struct drm_connector_helper_funcs st7586_connector_helper_funcs = {
314 DRM_MIPI_DBI_CONNECTOR_HELPER_FUNCS,
315 };
316
317 static const struct drm_connector_funcs st7586_connector_funcs = {
318 DRM_MIPI_DBI_CONNECTOR_FUNCS,
319 .destroy = drm_connector_cleanup,
320 };
321
322 static const struct drm_mode_config_helper_funcs st7586_mode_config_helper_funcs = {
323 DRM_MIPI_DBI_MODE_CONFIG_HELPER_FUNCS,
324 };
325
326 static const struct drm_mode_config_funcs st7586_mode_config_funcs = {
327 DRM_MIPI_DBI_MODE_CONFIG_FUNCS,
328 };
329
330 static const struct drm_display_mode st7586_mode = {
331 DRM_SIMPLE_MODE(178, 128, 37, 27),
332 };
333
334 DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
335
336 static const struct drm_driver st7586_driver = {
337 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
338 .fops = &st7586_fops,
339 DRM_GEM_DMA_DRIVER_OPS_VMAP,
340 DRM_FBDEV_DMA_DRIVER_OPS,
341 .debugfs_init = mipi_dbi_debugfs_init,
342 .name = "st7586",
343 .desc = "Sitronix ST7586",
344 .major = 1,
345 .minor = 0,
346 };
347
348 static const struct of_device_id st7586_of_match[] = {
349 { .compatible = "lego,ev3-lcd" },
350 {},
351 };
352 MODULE_DEVICE_TABLE(of, st7586_of_match);
353
354 static const struct spi_device_id st7586_id[] = {
355 { "ev3-lcd", 0 },
356 { },
357 };
358 MODULE_DEVICE_TABLE(spi, st7586_id);
359
st7586_probe(struct spi_device * spi)360 static int st7586_probe(struct spi_device *spi)
361 {
362 struct device *dev = &spi->dev;
363 struct st7586_device *st7586;
364 struct mipi_dbi_dev *dbidev;
365 struct drm_device *drm;
366 struct mipi_dbi *dbi;
367 struct gpio_desc *a0;
368 struct drm_plane *plane;
369 struct drm_crtc *crtc;
370 struct drm_encoder *encoder;
371 struct drm_connector *connector;
372 u32 rotation = 0;
373 size_t bufsize;
374 int ret;
375
376 st7586 = devm_drm_dev_alloc(dev, &st7586_driver, struct st7586_device, dbidev.drm);
377 if (IS_ERR(st7586))
378 return PTR_ERR(st7586);
379 dbidev = &st7586->dbidev;
380 dbi = &dbidev->dbi;
381 drm = &dbidev->drm;
382
383 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
384
385 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
386 if (IS_ERR(dbi->reset))
387 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
388
389 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
390 if (IS_ERR(a0))
391 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
392
393 device_property_read_u32(dev, "rotation", &rotation);
394
395 ret = mipi_dbi_spi_init(spi, dbi, a0);
396 if (ret)
397 return ret;
398
399 /*
400 * Override value set by mipi_dbi_spi_init(). This driver is a bit
401 * non-standard, so best to set it explicitly here.
402 */
403 dbi->write_memory_bpw = 8;
404
405 /* Cannot read from this controller via SPI */
406 dbi->read_commands = NULL;
407
408 ret = drm_mipi_dbi_dev_init(dbidev, &st7586_mode, st7586_plane_formats[0],
409 rotation, bufsize);
410 if (ret)
411 return ret;
412
413 ret = drmm_mode_config_init(drm);
414 if (ret)
415 return ret;
416
417 drm->mode_config.min_width = dbidev->mode.hdisplay;
418 drm->mode_config.max_width = dbidev->mode.hdisplay;
419 drm->mode_config.min_height = dbidev->mode.vdisplay;
420 drm->mode_config.max_height = dbidev->mode.vdisplay;
421 drm->mode_config.funcs = &st7586_mode_config_funcs;
422 drm->mode_config.preferred_depth = 24;
423 drm->mode_config.helper_private = &st7586_mode_config_helper_funcs;
424
425 plane = &st7586->plane;
426 ret = drm_universal_plane_init(drm, plane, 0, &st7586_plane_funcs,
427 st7586_plane_formats, ARRAY_SIZE(st7586_plane_formats),
428 st7586_plane_format_modifiers,
429 DRM_PLANE_TYPE_PRIMARY, NULL);
430 if (ret)
431 return ret;
432 drm_plane_helper_add(plane, &st7586_plane_helper_funcs);
433 drm_plane_enable_fb_damage_clips(plane);
434
435 crtc = &st7586->crtc;
436 ret = drm_crtc_init_with_planes(drm, crtc, plane, NULL, &st7586_crtc_funcs, NULL);
437 if (ret)
438 return ret;
439 drm_crtc_helper_add(crtc, &st7586_crtc_helper_funcs);
440
441 encoder = &st7586->encoder;
442 ret = drm_encoder_init(drm, encoder, &st7586_encoder_funcs, DRM_MODE_ENCODER_NONE, NULL);
443 if (ret)
444 return ret;
445 encoder->possible_crtcs = drm_crtc_mask(crtc);
446
447 connector = &st7586->connector;
448 ret = drm_connector_init(drm, connector, &st7586_connector_funcs,
449 DRM_MODE_CONNECTOR_SPI);
450 if (ret)
451 return ret;
452 drm_connector_helper_add(connector, &st7586_connector_helper_funcs);
453
454 ret = drm_connector_attach_encoder(connector, encoder);
455 if (ret)
456 return ret;
457
458 drm_mode_config_reset(drm);
459
460 ret = drm_dev_register(drm, 0);
461 if (ret)
462 return ret;
463
464 spi_set_drvdata(spi, drm);
465
466 drm_client_setup(drm, NULL);
467
468 return 0;
469 }
470
st7586_remove(struct spi_device * spi)471 static void st7586_remove(struct spi_device *spi)
472 {
473 struct drm_device *drm = spi_get_drvdata(spi);
474
475 drm_dev_unplug(drm);
476 drm_atomic_helper_shutdown(drm);
477 }
478
st7586_shutdown(struct spi_device * spi)479 static void st7586_shutdown(struct spi_device *spi)
480 {
481 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
482 }
483
484 static struct spi_driver st7586_spi_driver = {
485 .driver = {
486 .name = "st7586",
487 .of_match_table = st7586_of_match,
488 },
489 .id_table = st7586_id,
490 .probe = st7586_probe,
491 .remove = st7586_remove,
492 .shutdown = st7586_shutdown,
493 };
494 module_spi_driver(st7586_spi_driver);
495
496 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
497 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
498 MODULE_LICENSE("GPL");
499