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_damage_helper.h>
21#include <drm/drm_drv.h>
22#include <drm/drm_fb_cma_helper.h>
23#include <drm/drm_gem_cma_helper.h>
24#include <drm/drm_gem_framebuffer_helper.h>
25#include <drm/drm_rect.h>
26#include <drm/drm_vblank.h>
27#include <drm/tinydrm/mipi-dbi.h>
28#include <drm/tinydrm/tinydrm-helpers.h>
29
30/* controller-specific commands */
31#define ST7586_DISP_MODE_GRAY 0x38
32#define ST7586_DISP_MODE_MONO 0x39
33#define ST7586_ENABLE_DDRAM 0x3a
34#define ST7586_SET_DISP_DUTY 0xb0
35#define ST7586_SET_PART_DISP 0xb4
36#define ST7586_SET_NLINE_INV 0xb5
37#define ST7586_SET_VOP 0xc0
38#define ST7586_SET_BIAS_SYSTEM 0xc3
39#define ST7586_SET_BOOST_LEVEL 0xc4
40#define ST7586_SET_VOP_OFFSET 0xc7
41#define ST7586_ENABLE_ANALOG 0xd0
42#define ST7586_AUTO_READ_CTRL 0xd7
43#define ST7586_OTP_RW_CTRL 0xe0
44#define ST7586_OTP_CTRL_OUT 0xe1
45#define ST7586_OTP_READ 0xe3
46
47#define ST7586_DISP_CTRL_MX BIT(6)
48#define ST7586_DISP_CTRL_MY BIT(7)
49
50/*
51 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
52 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
53 * pixel using only 2 bits.
54 *
55 * | D7 | D6 | D5 || | || 2bpp |
56 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |
57 * +------+------+------++------+------++------+
58 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black
59 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray
60 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray
61 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white
62 */
63
64static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
65
66static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
67 struct drm_framebuffer *fb,
68 struct drm_rect *clip)
69{
70 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
71 unsigned int x, y;
72 u8 *src, *buf, val;
73
74 buf = kmalloc(len, GFP_KERNEL);
75 if (!buf)
76 return;
77
78 tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
79 src = buf;
80
81 for (y = clip->y1; y < clip->y2; y++) {
82 for (x = clip->x1; x < clip->x2; x += 3) {
83 val = st7586_lookup[*src++ >> 6] << 5;
84 val |= st7586_lookup[*src++ >> 6] << 2;
85 val |= st7586_lookup[*src++ >> 6] >> 1;
86 *dst++ = val;
87 }
88 }
89
90 kfree(buf);
91}
92
93static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
94 struct drm_rect *clip)
95{
96 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
97 struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
98 void *src = cma_obj->vaddr;
99 int ret = 0;
100
101 if (import_attach) {
102 ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
103 DMA_FROM_DEVICE);
104 if (ret)
105 return ret;
106 }
107
108 st7586_xrgb8888_to_gray332(dst, src, fb, clip);
109
110 if (import_attach)
111 ret = dma_buf_end_cpu_access(import_attach->dmabuf,
112 DMA_FROM_DEVICE);
113
114 return ret;
115}
116
117static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect)
118{
119 struct tinydrm_device *tdev = fb->dev->dev_private;
120 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
121 int start, end;
122 int ret = 0;
123
124 if (!mipi->enabled)
125 return;
126
127 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
128 rect->x1 = rounddown(rect->x1, 3);
129 rect->x2 = roundup(rect->x2, 3);
130
131 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
132
133 ret = st7586_buf_copy(mipi->tx_buf, fb, rect);
134 if (ret)
135 goto err_msg;
136
137 /* Pixels are packed 3 per byte */
138 start = rect->x1 / 3;
139 end = rect->x2 / 3;
140
141 mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
142 (start >> 8) & 0xFF, start & 0xFF,
143 (end >> 8) & 0xFF, (end - 1) & 0xFF);
144 mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
145 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
146 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
147
148 ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
149 (u8 *)mipi->tx_buf,
150 (end - start) * (rect->y2 - rect->y1));
151err_msg:
152 if (ret)
153 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
154}
155
156static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
157 struct drm_plane_state *old_state)
158{
159 struct drm_plane_state *state = pipe->plane.state;
160 struct drm_crtc *crtc = &pipe->crtc;
161 struct drm_rect rect;
162
163 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
164 st7586_fb_dirty(state->fb, &rect);
165
166 if (crtc->state->event) {
167 spin_lock_irq(&crtc->dev->event_lock);
168 drm_crtc_send_vblank_event(crtc, crtc->state->event);
169 spin_unlock_irq(&crtc->dev->event_lock);
170 crtc->state->event = NULL;
171 }
172}
173
174static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
175 struct drm_crtc_state *crtc_state,
176 struct drm_plane_state *plane_state)
177{
178 struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
179 struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
180 struct drm_framebuffer *fb = plane_state->fb;
181 struct drm_rect rect = {
182 .x1 = 0,
183 .x2 = fb->width,
184 .y1 = 0,
185 .y2 = fb->height,
186 };
187 int ret;
188 u8 addr_mode;
189
190 DRM_DEBUG_KMS("\n");
191
192 ret = mipi_dbi_poweron_reset(mipi);
193 if (ret)
194 return;
195
196 mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
197 mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
198
199 msleep(10);
200
201 mipi_dbi_command(mipi, ST7586_OTP_READ);
202
203 msleep(20);
204
205 mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
206 mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
207 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
208
209 msleep(50);
210
211 mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
212 mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
213 mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
214 mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
215 mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
216 mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
217 mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
218 mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
219
220 switch (mipi->rotation) {
221 default:
222 addr_mode = 0x00;
223 break;
224 case 90:
225 addr_mode = ST7586_DISP_CTRL_MY;
226 break;
227 case 180:
228 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
229 break;
230 case 270:
231 addr_mode = ST7586_DISP_CTRL_MX;
232 break;
233 }
234 mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
235
236 mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
237 mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
238 mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
239 mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
240
241 msleep(100);
242
243 mipi->enabled = true;
244 st7586_fb_dirty(fb, &rect);
245
246 mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
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, 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 drm_plane_enable_fb_damage_clips(&tdev->pipe.plane);
295
296 tdev->drm->mode_config.preferred_depth = 32;
297 mipi->rotation = rotation;
298
299 drm_mode_config_reset(tdev->drm);
300
301 DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
302 tdev->drm->mode_config.preferred_depth, rotation);
303
304 return 0;
305}
306
307static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
308 .enable = st7586_pipe_enable,
309 .disable = st7586_pipe_disable,
310 .update = st7586_pipe_update,
311 .prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
312};
313
314static const struct drm_display_mode st7586_mode = {
315 TINYDRM_MODE(178, 128, 37, 27),
316};
317
318DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
319
320static struct drm_driver st7586_driver = {
321 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
322 DRIVER_ATOMIC,
323 .fops = &st7586_fops,
324 DRM_GEM_CMA_VMAP_DRIVER_OPS,
325 .debugfs_init = mipi_dbi_debugfs_init,
326 .name = "st7586",
327 .desc = "Sitronix ST7586",
328 .date = "20170801",
329 .major = 1,
330 .minor = 0,
331};
332
333static const struct of_device_id st7586_of_match[] = {
334 { .compatible = "lego,ev3-lcd" },
335 {},
336};
337MODULE_DEVICE_TABLE(of, st7586_of_match);
338
339static const struct spi_device_id st7586_id[] = {
340 { "ev3-lcd", 0 },
341 { },
342};
343MODULE_DEVICE_TABLE(spi, st7586_id);
344
345static int st7586_probe(struct spi_device *spi)
346{
347 struct device *dev = &spi->dev;
348 struct mipi_dbi *mipi;
349 struct gpio_desc *a0;
350 u32 rotation = 0;
351 int ret;
352
353 mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
354 if (!mipi)
355 return -ENOMEM;
356
357 mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
358 if (IS_ERR(mipi->reset)) {
359 DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
360 return PTR_ERR(mipi->reset);
361 }
362
363 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
364 if (IS_ERR(a0)) {
365 DRM_DEV_ERROR(dev, "Failed to get gpio 'a0'\n");
366 return PTR_ERR(a0);
367 }
368
369 device_property_read_u32(dev, "rotation", &rotation);
370
371 ret = mipi_dbi_spi_init(spi, mipi, a0);
372 if (ret)
373 return ret;
374
375 /* Cannot read from this controller via SPI */
376 mipi->read_commands = NULL;
377
378 /*
379 * we are using 8-bit data, so we are not actually swapping anything,
380 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
381 * right thing and not use 16-bit transfers (which results in swapped
382 * bytes on little-endian systems and causes out of order data to be
383 * sent to the display).
384 */
385 mipi->swap_bytes = true;
386
387 ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
388 &st7586_mode, rotation);
389 if (ret)
390 return ret;
391
392 spi_set_drvdata(spi, mipi);
393
394 return devm_tinydrm_register(&mipi->tinydrm);
395}
396
397static void st7586_shutdown(struct spi_device *spi)
398{
399 struct mipi_dbi *mipi = spi_get_drvdata(spi);
400
401 tinydrm_shutdown(&mipi->tinydrm);
402}
403
404static struct spi_driver st7586_spi_driver = {
405 .driver = {
406 .name = "st7586",
407 .owner = THIS_MODULE,
408 .of_match_table = st7586_of_match,
409 },
410 .id_table = st7586_id,
411 .probe = st7586_probe,
412 .shutdown = st7586_shutdown,
413};
414module_spi_driver(st7586_spi_driver);
415
416MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
417MODULE_AUTHOR("David Lechner <david@lechnology.com>");
418MODULE_LICENSE("GPL");