1 /*
2  * Copyright (C) 2014 NVIDIA Corporation
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/backlight.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/regulator/consumer.h>
14 
15 #include <drm/drmP.h>
16 #include <drm/drm_crtc.h>
17 #include <drm/drm_mipi_dsi.h>
18 #include <drm/drm_panel.h>
19 
20 #include <video/mipi_display.h>
21 
22 struct sharp_panel {
23 	struct drm_panel base;
24 	/* the datasheet refers to them as DSI-LINK1 and DSI-LINK2 */
25 	struct mipi_dsi_device *link1;
26 	struct mipi_dsi_device *link2;
27 
28 	struct backlight_device *backlight;
29 	struct regulator *supply;
30 
31 	bool prepared;
32 	bool enabled;
33 
34 	const struct drm_display_mode *mode;
35 };
36 
37 static inline struct sharp_panel *to_sharp_panel(struct drm_panel *panel)
38 {
39 	return container_of(panel, struct sharp_panel, base);
40 }
41 
42 static void sharp_wait_frames(struct sharp_panel *sharp, unsigned int frames)
43 {
44 	unsigned int refresh = drm_mode_vrefresh(sharp->mode);
45 
46 	if (WARN_ON(frames > refresh))
47 		return;
48 
49 	msleep(1000 / (refresh / frames));
50 }
51 
52 static int sharp_panel_write(struct sharp_panel *sharp, u16 offset, u8 value)
53 {
54 	u8 payload[3] = { offset >> 8, offset & 0xff, value };
55 	struct mipi_dsi_device *dsi = sharp->link1;
56 	ssize_t err;
57 
58 	err = mipi_dsi_generic_write(dsi, payload, sizeof(payload));
59 	if (err < 0) {
60 		dev_err(&dsi->dev, "failed to write %02x to %04x: %zd\n",
61 			value, offset, err);
62 		return err;
63 	}
64 
65 	err = mipi_dsi_dcs_nop(dsi);
66 	if (err < 0) {
67 		dev_err(&dsi->dev, "failed to send DCS nop: %zd\n", err);
68 		return err;
69 	}
70 
71 	usleep_range(10, 20);
72 
73 	return 0;
74 }
75 
76 static __maybe_unused int sharp_panel_read(struct sharp_panel *sharp,
77 					   u16 offset, u8 *value)
78 {
79 	ssize_t err;
80 
81 	cpu_to_be16s(&offset);
82 
83 	err = mipi_dsi_generic_read(sharp->link1, &offset, sizeof(offset),
84 				    value, sizeof(*value));
85 	if (err < 0)
86 		dev_err(&sharp->link1->dev, "failed to read from %04x: %zd\n",
87 			offset, err);
88 
89 	return err;
90 }
91 
92 static int sharp_panel_disable(struct drm_panel *panel)
93 {
94 	struct sharp_panel *sharp = to_sharp_panel(panel);
95 
96 	if (!sharp->enabled)
97 		return 0;
98 
99 	if (sharp->backlight) {
100 		sharp->backlight->props.power = FB_BLANK_POWERDOWN;
101 		backlight_update_status(sharp->backlight);
102 	}
103 
104 	sharp->enabled = false;
105 
106 	return 0;
107 }
108 
109 static int sharp_panel_unprepare(struct drm_panel *panel)
110 {
111 	struct sharp_panel *sharp = to_sharp_panel(panel);
112 	int err;
113 
114 	if (!sharp->prepared)
115 		return 0;
116 
117 	sharp_wait_frames(sharp, 4);
118 
119 	err = mipi_dsi_dcs_set_display_off(sharp->link1);
120 	if (err < 0)
121 		dev_err(panel->dev, "failed to set display off: %d\n", err);
122 
123 	err = mipi_dsi_dcs_enter_sleep_mode(sharp->link1);
124 	if (err < 0)
125 		dev_err(panel->dev, "failed to enter sleep mode: %d\n", err);
126 
127 	msleep(120);
128 
129 	regulator_disable(sharp->supply);
130 
131 	sharp->prepared = false;
132 
133 	return 0;
134 }
135 
136 static int sharp_setup_symmetrical_split(struct mipi_dsi_device *left,
137 					 struct mipi_dsi_device *right,
138 					 const struct drm_display_mode *mode)
139 {
140 	int err;
141 
142 	err = mipi_dsi_dcs_set_column_address(left, 0, mode->hdisplay / 2 - 1);
143 	if (err < 0) {
144 		dev_err(&left->dev, "failed to set column address: %d\n", err);
145 		return err;
146 	}
147 
148 	err = mipi_dsi_dcs_set_page_address(left, 0, mode->vdisplay - 1);
149 	if (err < 0) {
150 		dev_err(&left->dev, "failed to set page address: %d\n", err);
151 		return err;
152 	}
153 
154 	err = mipi_dsi_dcs_set_column_address(right, mode->hdisplay / 2,
155 					      mode->hdisplay - 1);
156 	if (err < 0) {
157 		dev_err(&right->dev, "failed to set column address: %d\n", err);
158 		return err;
159 	}
160 
161 	err = mipi_dsi_dcs_set_page_address(right, 0, mode->vdisplay - 1);
162 	if (err < 0) {
163 		dev_err(&right->dev, "failed to set page address: %d\n", err);
164 		return err;
165 	}
166 
167 	return 0;
168 }
169 
170 static int sharp_panel_prepare(struct drm_panel *panel)
171 {
172 	struct sharp_panel *sharp = to_sharp_panel(panel);
173 	u8 format = MIPI_DCS_PIXEL_FMT_24BIT;
174 	int err;
175 
176 	if (sharp->prepared)
177 		return 0;
178 
179 	err = regulator_enable(sharp->supply);
180 	if (err < 0)
181 		return err;
182 
183 	/*
184 	 * According to the datasheet, the panel needs around 10 ms to fully
185 	 * power up. At least another 120 ms is required before exiting sleep
186 	 * mode to make sure the panel is ready. Throw in another 20 ms for
187 	 * good measure.
188 	 */
189 	msleep(150);
190 
191 	err = mipi_dsi_dcs_exit_sleep_mode(sharp->link1);
192 	if (err < 0) {
193 		dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
194 		goto poweroff;
195 	}
196 
197 	/*
198 	 * The MIPI DCS specification mandates this delay only between the
199 	 * exit_sleep_mode and enter_sleep_mode commands, so it isn't strictly
200 	 * necessary here.
201 	 */
202 	/*
203 	msleep(120);
204 	*/
205 
206 	/* set left-right mode */
207 	err = sharp_panel_write(sharp, 0x1000, 0x2a);
208 	if (err < 0) {
209 		dev_err(panel->dev, "failed to set left-right mode: %d\n", err);
210 		goto poweroff;
211 	}
212 
213 	/* enable command mode */
214 	err = sharp_panel_write(sharp, 0x1001, 0x01);
215 	if (err < 0) {
216 		dev_err(panel->dev, "failed to enable command mode: %d\n", err);
217 		goto poweroff;
218 	}
219 
220 	err = mipi_dsi_dcs_set_pixel_format(sharp->link1, format);
221 	if (err < 0) {
222 		dev_err(panel->dev, "failed to set pixel format: %d\n", err);
223 		goto poweroff;
224 	}
225 
226 	/*
227 	 * TODO: The device supports both left-right and even-odd split
228 	 * configurations, but this driver currently supports only the left-
229 	 * right split. To support a different mode a mechanism needs to be
230 	 * put in place to communicate the configuration back to the DSI host
231 	 * controller.
232 	 */
233 	err = sharp_setup_symmetrical_split(sharp->link1, sharp->link2,
234 					    sharp->mode);
235 	if (err < 0) {
236 		dev_err(panel->dev, "failed to set up symmetrical split: %d\n",
237 			err);
238 		goto poweroff;
239 	}
240 
241 	err = mipi_dsi_dcs_set_display_on(sharp->link1);
242 	if (err < 0) {
243 		dev_err(panel->dev, "failed to set display on: %d\n", err);
244 		goto poweroff;
245 	}
246 
247 	sharp->prepared = true;
248 
249 	/* wait for 6 frames before continuing */
250 	sharp_wait_frames(sharp, 6);
251 
252 	return 0;
253 
254 poweroff:
255 	regulator_disable(sharp->supply);
256 	return err;
257 }
258 
259 static int sharp_panel_enable(struct drm_panel *panel)
260 {
261 	struct sharp_panel *sharp = to_sharp_panel(panel);
262 
263 	if (sharp->enabled)
264 		return 0;
265 
266 	if (sharp->backlight) {
267 		sharp->backlight->props.power = FB_BLANK_UNBLANK;
268 		backlight_update_status(sharp->backlight);
269 	}
270 
271 	sharp->enabled = true;
272 
273 	return 0;
274 }
275 
276 static const struct drm_display_mode default_mode = {
277 	.clock = 278000,
278 	.hdisplay = 2560,
279 	.hsync_start = 2560 + 128,
280 	.hsync_end = 2560 + 128 + 64,
281 	.htotal = 2560 + 128 + 64 + 64,
282 	.vdisplay = 1600,
283 	.vsync_start = 1600 + 4,
284 	.vsync_end = 1600 + 4 + 8,
285 	.vtotal = 1600 + 4 + 8 + 32,
286 	.vrefresh = 60,
287 };
288 
289 static int sharp_panel_get_modes(struct drm_panel *panel)
290 {
291 	struct drm_display_mode *mode;
292 
293 	mode = drm_mode_duplicate(panel->drm, &default_mode);
294 	if (!mode) {
295 		dev_err(panel->drm->dev, "failed to add mode %ux%ux@%u\n",
296 			default_mode.hdisplay, default_mode.vdisplay,
297 			default_mode.vrefresh);
298 		return -ENOMEM;
299 	}
300 
301 	drm_mode_set_name(mode);
302 
303 	drm_mode_probed_add(panel->connector, mode);
304 
305 	panel->connector->display_info.width_mm = 217;
306 	panel->connector->display_info.height_mm = 136;
307 
308 	return 1;
309 }
310 
311 static const struct drm_panel_funcs sharp_panel_funcs = {
312 	.disable = sharp_panel_disable,
313 	.unprepare = sharp_panel_unprepare,
314 	.prepare = sharp_panel_prepare,
315 	.enable = sharp_panel_enable,
316 	.get_modes = sharp_panel_get_modes,
317 };
318 
319 static const struct of_device_id sharp_of_match[] = {
320 	{ .compatible = "sharp,lq101r1sx01", },
321 	{ }
322 };
323 MODULE_DEVICE_TABLE(of, sharp_of_match);
324 
325 static int sharp_panel_add(struct sharp_panel *sharp)
326 {
327 	struct device_node *np;
328 	int err;
329 
330 	sharp->mode = &default_mode;
331 
332 	sharp->supply = devm_regulator_get(&sharp->link1->dev, "power");
333 	if (IS_ERR(sharp->supply))
334 		return PTR_ERR(sharp->supply);
335 
336 	np = of_parse_phandle(sharp->link1->dev.of_node, "backlight", 0);
337 	if (np) {
338 		sharp->backlight = of_find_backlight_by_node(np);
339 		of_node_put(np);
340 
341 		if (!sharp->backlight)
342 			return -EPROBE_DEFER;
343 	}
344 
345 	drm_panel_init(&sharp->base);
346 	sharp->base.funcs = &sharp_panel_funcs;
347 	sharp->base.dev = &sharp->link1->dev;
348 
349 	err = drm_panel_add(&sharp->base);
350 	if (err < 0)
351 		goto put_backlight;
352 
353 	return 0;
354 
355 put_backlight:
356 	if (sharp->backlight)
357 		put_device(&sharp->backlight->dev);
358 
359 	return err;
360 }
361 
362 static void sharp_panel_del(struct sharp_panel *sharp)
363 {
364 	if (sharp->base.dev)
365 		drm_panel_remove(&sharp->base);
366 
367 	if (sharp->backlight)
368 		put_device(&sharp->backlight->dev);
369 
370 	if (sharp->link2)
371 		put_device(&sharp->link2->dev);
372 }
373 
374 static int sharp_panel_probe(struct mipi_dsi_device *dsi)
375 {
376 	struct mipi_dsi_device *secondary = NULL;
377 	struct sharp_panel *sharp;
378 	struct device_node *np;
379 	int err;
380 
381 	dsi->lanes = 4;
382 	dsi->format = MIPI_DSI_FMT_RGB888;
383 	dsi->mode_flags = MIPI_DSI_MODE_LPM;
384 
385 	/* Find DSI-LINK1 */
386 	np = of_parse_phandle(dsi->dev.of_node, "link2", 0);
387 	if (np) {
388 		secondary = of_find_mipi_dsi_device_by_node(np);
389 		of_node_put(np);
390 
391 		if (!secondary)
392 			return -EPROBE_DEFER;
393 	}
394 
395 	/* register a panel for only the DSI-LINK1 interface */
396 	if (secondary) {
397 		sharp = devm_kzalloc(&dsi->dev, sizeof(*sharp), GFP_KERNEL);
398 		if (!sharp) {
399 			put_device(&secondary->dev);
400 			return -ENOMEM;
401 		}
402 
403 		mipi_dsi_set_drvdata(dsi, sharp);
404 
405 		sharp->link2 = secondary;
406 		sharp->link1 = dsi;
407 
408 		err = sharp_panel_add(sharp);
409 		if (err < 0) {
410 			put_device(&secondary->dev);
411 			return err;
412 		}
413 	}
414 
415 	err = mipi_dsi_attach(dsi);
416 	if (err < 0) {
417 		if (secondary)
418 			sharp_panel_del(sharp);
419 
420 		return err;
421 	}
422 
423 	return 0;
424 }
425 
426 static int sharp_panel_remove(struct mipi_dsi_device *dsi)
427 {
428 	struct sharp_panel *sharp = mipi_dsi_get_drvdata(dsi);
429 	int err;
430 
431 	/* only detach from host for the DSI-LINK2 interface */
432 	if (!sharp) {
433 		mipi_dsi_detach(dsi);
434 		return 0;
435 	}
436 
437 	err = sharp_panel_disable(&sharp->base);
438 	if (err < 0)
439 		dev_err(&dsi->dev, "failed to disable panel: %d\n", err);
440 
441 	err = mipi_dsi_detach(dsi);
442 	if (err < 0)
443 		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);
444 
445 	drm_panel_detach(&sharp->base);
446 	sharp_panel_del(sharp);
447 
448 	return 0;
449 }
450 
451 static void sharp_panel_shutdown(struct mipi_dsi_device *dsi)
452 {
453 	struct sharp_panel *sharp = mipi_dsi_get_drvdata(dsi);
454 
455 	/* nothing to do for DSI-LINK2 */
456 	if (!sharp)
457 		return;
458 
459 	sharp_panel_disable(&sharp->base);
460 }
461 
462 static struct mipi_dsi_driver sharp_panel_driver = {
463 	.driver = {
464 		.name = "panel-sharp-lq101r1sx01",
465 		.of_match_table = sharp_of_match,
466 	},
467 	.probe = sharp_panel_probe,
468 	.remove = sharp_panel_remove,
469 	.shutdown = sharp_panel_shutdown,
470 };
471 module_mipi_dsi_driver(sharp_panel_driver);
472 
473 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
474 MODULE_DESCRIPTION("Sharp LQ101R1SX01 panel driver");
475 MODULE_LICENSE("GPL v2");
476