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_helper.h>
17 #include <drm/drm_damage_helper.h>
18 #include <drm/drm_drv.h>
19 #include <drm/drm_fb_dma_helper.h>
20 #include <drm/drm_fbdev_dma.h>
21 #include <drm/drm_format_helper.h>
22 #include <drm/drm_framebuffer.h>
23 #include <drm/drm_gem_atomic_helper.h>
24 #include <drm/drm_gem_dma_helper.h>
25 #include <drm/drm_gem_framebuffer_helper.h>
26 #include <drm/drm_managed.h>
27 #include <drm/drm_mipi_dbi.h>
28 #include <drm/drm_print.h>
29 #include <drm/drm_rect.h>
30
31 /* controller-specific commands */
32 #define ST7586_DISP_MODE_GRAY 0x38
33 #define ST7586_DISP_MODE_MONO 0x39
34 #define ST7586_ENABLE_DDRAM 0x3a
35 #define ST7586_SET_DISP_DUTY 0xb0
36 #define ST7586_SET_PART_DISP 0xb4
37 #define ST7586_SET_NLINE_INV 0xb5
38 #define ST7586_SET_VOP 0xc0
39 #define ST7586_SET_BIAS_SYSTEM 0xc3
40 #define ST7586_SET_BOOST_LEVEL 0xc4
41 #define ST7586_SET_VOP_OFFSET 0xc7
42 #define ST7586_ENABLE_ANALOG 0xd0
43 #define ST7586_AUTO_READ_CTRL 0xd7
44 #define ST7586_OTP_RW_CTRL 0xe0
45 #define ST7586_OTP_CTRL_OUT 0xe1
46 #define ST7586_OTP_READ 0xe3
47
48 #define ST7586_DISP_CTRL_MX BIT(6)
49 #define ST7586_DISP_CTRL_MY BIT(7)
50
51 /*
52 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is
53 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd
54 * pixel using only 2 bits.
55 *
56 * | D7 | D6 | D5 || | || 2bpp |
57 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY |
58 * +------+------+------++------+------++------+
59 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black
60 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray
61 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray
62 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white
63 */
64
65 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 };
66
st7586_xrgb8888_to_gray332(u8 * dst,void * vaddr,struct drm_framebuffer * fb,struct drm_rect * clip,struct drm_format_conv_state * fmtcnv_state)67 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
68 struct drm_framebuffer *fb,
69 struct drm_rect *clip,
70 struct drm_format_conv_state *fmtcnv_state)
71 {
72 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
73 unsigned int x, y;
74 u8 *src, *buf, val;
75 struct iosys_map dst_map, vmap;
76
77 buf = kmalloc(len, GFP_KERNEL);
78 if (!buf)
79 return;
80
81 iosys_map_set_vaddr(&dst_map, buf);
82 iosys_map_set_vaddr(&vmap, vaddr);
83 drm_fb_xrgb8888_to_gray8(&dst_map, NULL, &vmap, fb, clip, fmtcnv_state);
84 src = buf;
85
86 for (y = clip->y1; y < clip->y2; y++) {
87 for (x = clip->x1; x < clip->x2; x += 3) {
88 val = st7586_lookup[*src++ >> 6] << 5;
89 val |= st7586_lookup[*src++ >> 6] << 2;
90 val |= st7586_lookup[*src++ >> 6] >> 1;
91 *dst++ = val;
92 }
93 }
94
95 kfree(buf);
96 }
97
st7586_buf_copy(void * dst,struct iosys_map * src,struct drm_framebuffer * fb,struct drm_rect * clip,struct drm_format_conv_state * fmtcnv_state)98 static int st7586_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,
99 struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)
100 {
101 int ret;
102
103 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
104 if (ret)
105 return ret;
106
107 st7586_xrgb8888_to_gray332(dst, src->vaddr, fb, clip, fmtcnv_state);
108
109 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
110
111 return 0;
112 }
113
st7586_fb_dirty(struct iosys_map * src,struct drm_framebuffer * fb,struct drm_rect * rect,struct drm_format_conv_state * fmtcnv_state)114 static void st7586_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
115 struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
116 {
117 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
118 struct mipi_dbi *dbi = &dbidev->dbi;
119 int start, end, ret = 0;
120
121 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
122 rect->x1 = rounddown(rect->x1, 3);
123 rect->x2 = roundup(rect->x2, 3);
124
125 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
126
127 ret = st7586_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);
128 if (ret)
129 goto err_msg;
130
131 /* Pixels are packed 3 per byte */
132 start = rect->x1 / 3;
133 end = rect->x2 / 3;
134
135 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS,
136 (start >> 8) & 0xFF, start & 0xFF,
137 (end >> 8) & 0xFF, (end - 1) & 0xFF);
138 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS,
139 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF,
140 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF);
141
142 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START,
143 (u8 *)dbidev->tx_buf,
144 (end - start) * (rect->y2 - rect->y1));
145 err_msg:
146 if (ret)
147 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
148 }
149
st7586_pipe_update(struct drm_simple_display_pipe * pipe,struct drm_plane_state * old_state)150 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe,
151 struct drm_plane_state *old_state)
152 {
153 struct drm_plane_state *state = pipe->plane.state;
154 struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
155 struct drm_framebuffer *fb = state->fb;
156 struct drm_rect rect;
157 int idx;
158
159 if (!pipe->crtc.state->active)
160 return;
161
162 if (!drm_dev_enter(fb->dev, &idx))
163 return;
164
165 if (drm_atomic_helper_damage_merged(old_state, state, &rect))
166 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
167 &shadow_plane_state->fmtcnv_state);
168
169 drm_dev_exit(idx);
170 }
171
st7586_pipe_enable(struct drm_simple_display_pipe * pipe,struct drm_crtc_state * crtc_state,struct drm_plane_state * plane_state)172 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
173 struct drm_crtc_state *crtc_state,
174 struct drm_plane_state *plane_state)
175 {
176 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
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 mipi_dbi *dbi = &dbidev->dbi;
180 struct drm_rect rect = {
181 .x1 = 0,
182 .x2 = fb->width,
183 .y1 = 0,
184 .y2 = fb->height,
185 };
186 int idx, ret;
187 u8 addr_mode;
188
189 if (!drm_dev_enter(pipe->crtc.dev, &idx))
190 return;
191
192 DRM_DEBUG_KMS("\n");
193
194 ret = mipi_dbi_poweron_reset(dbidev);
195 if (ret)
196 goto out_exit;
197
198 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f);
199 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00);
200
201 msleep(10);
202
203 mipi_dbi_command(dbi, ST7586_OTP_READ);
204
205 msleep(20);
206
207 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT);
208 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
209 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
210
211 msleep(50);
212
213 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00);
214 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00);
215 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02);
216 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04);
217 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d);
218 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00);
219 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY);
220 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02);
221
222 switch (dbidev->rotation) {
223 default:
224 addr_mode = 0x00;
225 break;
226 case 90:
227 addr_mode = ST7586_DISP_CTRL_MY;
228 break;
229 case 180:
230 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
231 break;
232 case 270:
233 addr_mode = ST7586_DISP_CTRL_MX;
234 break;
235 }
236 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
237
238 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f);
239 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0);
240 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77);
241 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE);
242
243 msleep(100);
244
245 st7586_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
246 &shadow_plane_state->fmtcnv_state);
247
248 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
249 out_exit:
250 drm_dev_exit(idx);
251 }
252
st7586_pipe_disable(struct drm_simple_display_pipe * pipe)253 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
254 {
255 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
256
257 /*
258 * This callback is not protected by drm_dev_enter/exit since we want to
259 * turn off the display on regular driver unload. It's highly unlikely
260 * that the underlying SPI controller is gone should this be called after
261 * unplug.
262 */
263
264 DRM_DEBUG_KMS("\n");
265
266 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
267 }
268
269 static const u32 st7586_formats[] = {
270 DRM_FORMAT_XRGB8888,
271 };
272
273 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
274 .mode_valid = mipi_dbi_pipe_mode_valid,
275 .enable = st7586_pipe_enable,
276 .disable = st7586_pipe_disable,
277 .update = st7586_pipe_update,
278 .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
279 .end_fb_access = mipi_dbi_pipe_end_fb_access,
280 .reset_plane = mipi_dbi_pipe_reset_plane,
281 .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
282 .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
283 };
284
285 static const struct drm_display_mode st7586_mode = {
286 DRM_SIMPLE_MODE(178, 128, 37, 27),
287 };
288
289 DEFINE_DRM_GEM_DMA_FOPS(st7586_fops);
290
291 static const struct drm_driver st7586_driver = {
292 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
293 .fops = &st7586_fops,
294 DRM_GEM_DMA_DRIVER_OPS_VMAP,
295 DRM_FBDEV_DMA_DRIVER_OPS,
296 .debugfs_init = mipi_dbi_debugfs_init,
297 .name = "st7586",
298 .desc = "Sitronix ST7586",
299 .major = 1,
300 .minor = 0,
301 };
302
303 static const struct of_device_id st7586_of_match[] = {
304 { .compatible = "lego,ev3-lcd" },
305 {},
306 };
307 MODULE_DEVICE_TABLE(of, st7586_of_match);
308
309 static const struct spi_device_id st7586_id[] = {
310 { "ev3-lcd", 0 },
311 { },
312 };
313 MODULE_DEVICE_TABLE(spi, st7586_id);
314
st7586_probe(struct spi_device * spi)315 static int st7586_probe(struct spi_device *spi)
316 {
317 struct device *dev = &spi->dev;
318 struct mipi_dbi_dev *dbidev;
319 struct drm_device *drm;
320 struct mipi_dbi *dbi;
321 struct gpio_desc *a0;
322 u32 rotation = 0;
323 size_t bufsize;
324 int ret;
325
326 dbidev = devm_drm_dev_alloc(dev, &st7586_driver,
327 struct mipi_dbi_dev, drm);
328 if (IS_ERR(dbidev))
329 return PTR_ERR(dbidev);
330
331 dbi = &dbidev->dbi;
332 drm = &dbidev->drm;
333
334 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay;
335
336 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
337 if (IS_ERR(dbi->reset))
338 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
339
340 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
341 if (IS_ERR(a0))
342 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
343
344 device_property_read_u32(dev, "rotation", &rotation);
345
346 ret = mipi_dbi_spi_init(spi, dbi, a0);
347 if (ret)
348 return ret;
349
350 /*
351 * Override value set by mipi_dbi_spi_init(). This driver is a bit
352 * non-standard, so best to set it explicitly here.
353 */
354 dbi->write_memory_bpw = 8;
355
356 /* Cannot read from this controller via SPI */
357 dbi->read_commands = NULL;
358
359 ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs,
360 st7586_formats, ARRAY_SIZE(st7586_formats),
361 &st7586_mode, rotation, bufsize);
362 if (ret)
363 return ret;
364
365 drm_mode_config_reset(drm);
366
367 ret = drm_dev_register(drm, 0);
368 if (ret)
369 return ret;
370
371 spi_set_drvdata(spi, drm);
372
373 drm_client_setup(drm, NULL);
374
375 return 0;
376 }
377
st7586_remove(struct spi_device * spi)378 static void st7586_remove(struct spi_device *spi)
379 {
380 struct drm_device *drm = spi_get_drvdata(spi);
381
382 drm_dev_unplug(drm);
383 drm_atomic_helper_shutdown(drm);
384 }
385
st7586_shutdown(struct spi_device * spi)386 static void st7586_shutdown(struct spi_device *spi)
387 {
388 drm_atomic_helper_shutdown(spi_get_drvdata(spi));
389 }
390
391 static struct spi_driver st7586_spi_driver = {
392 .driver = {
393 .name = "st7586",
394 .of_match_table = st7586_of_match,
395 },
396 .id_table = st7586_id,
397 .probe = st7586_probe,
398 .remove = st7586_remove,
399 .shutdown = st7586_shutdown,
400 };
401 module_spi_driver(st7586_spi_driver);
402
403 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
404 MODULE_AUTHOR("David Lechner <david@lechnology.com>");
405 MODULE_LICENSE("GPL");
406