1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 NVIDIA Corporation
4  */
5 
6 #include <linux/backlight.h>
7 #include <linux/gpio/consumer.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/regulator/consumer.h>
11 
12 #include <drm/drmP.h>
13 #include <drm/drm_crtc.h>
14 #include <drm/drm_mipi_dsi.h>
15 #include <drm/drm_panel.h>
16 
17 #include <video/mipi_display.h>
18 
19 struct sharp_panel {
20 	struct drm_panel base;
21 	/* the datasheet refers to them as DSI-LINK1 and DSI-LINK2 */
22 	struct mipi_dsi_device *link1;
23 	struct mipi_dsi_device *link2;
24 
25 	struct backlight_device *backlight;
26 	struct regulator *supply;
27 
28 	bool prepared;
29 	bool enabled;
30 
31 	const struct drm_display_mode *mode;
32 };
33 
34 static inline struct sharp_panel *to_sharp_panel(struct drm_panel *panel)
35 {
36 	return container_of(panel, struct sharp_panel, base);
37 }
38 
39 static void sharp_wait_frames(struct sharp_panel *sharp, unsigned int frames)
40 {
41 	unsigned int refresh = drm_mode_vrefresh(sharp->mode);
42 
43 	if (WARN_ON(frames > refresh))
44 		return;
45 
46 	msleep(1000 / (refresh / frames));
47 }
48 
49 static int sharp_panel_write(struct sharp_panel *sharp, u16 offset, u8 value)
50 {
51 	u8 payload[3] = { offset >> 8, offset & 0xff, value };
52 	struct mipi_dsi_device *dsi = sharp->link1;
53 	ssize_t err;
54 
55 	err = mipi_dsi_generic_write(dsi, payload, sizeof(payload));
56 	if (err < 0) {
57 		dev_err(&dsi->dev, "failed to write %02x to %04x: %zd\n",
58 			value, offset, err);
59 		return err;
60 	}
61 
62 	err = mipi_dsi_dcs_nop(dsi);
63 	if (err < 0) {
64 		dev_err(&dsi->dev, "failed to send DCS nop: %zd\n", err);
65 		return err;
66 	}
67 
68 	usleep_range(10, 20);
69 
70 	return 0;
71 }
72 
73 static __maybe_unused int sharp_panel_read(struct sharp_panel *sharp,
74 					   u16 offset, u8 *value)
75 {
76 	ssize_t err;
77 
78 	cpu_to_be16s(&offset);
79 
80 	err = mipi_dsi_generic_read(sharp->link1, &offset, sizeof(offset),
81 				    value, sizeof(*value));
82 	if (err < 0)
83 		dev_err(&sharp->link1->dev, "failed to read from %04x: %zd\n",
84 			offset, err);
85 
86 	return err;
87 }
88 
89 static int sharp_panel_disable(struct drm_panel *panel)
90 {
91 	struct sharp_panel *sharp = to_sharp_panel(panel);
92 
93 	if (!sharp->enabled)
94 		return 0;
95 
96 	backlight_disable(sharp->backlight);
97 
98 	sharp->enabled = false;
99 
100 	return 0;
101 }
102 
103 static int sharp_panel_unprepare(struct drm_panel *panel)
104 {
105 	struct sharp_panel *sharp = to_sharp_panel(panel);
106 	int err;
107 
108 	if (!sharp->prepared)
109 		return 0;
110 
111 	sharp_wait_frames(sharp, 4);
112 
113 	err = mipi_dsi_dcs_set_display_off(sharp->link1);
114 	if (err < 0)
115 		dev_err(panel->dev, "failed to set display off: %d\n", err);
116 
117 	err = mipi_dsi_dcs_enter_sleep_mode(sharp->link1);
118 	if (err < 0)
119 		dev_err(panel->dev, "failed to enter sleep mode: %d\n", err);
120 
121 	msleep(120);
122 
123 	regulator_disable(sharp->supply);
124 
125 	sharp->prepared = false;
126 
127 	return 0;
128 }
129 
130 static int sharp_setup_symmetrical_split(struct mipi_dsi_device *left,
131 					 struct mipi_dsi_device *right,
132 					 const struct drm_display_mode *mode)
133 {
134 	int err;
135 
136 	err = mipi_dsi_dcs_set_column_address(left, 0, mode->hdisplay / 2 - 1);
137 	if (err < 0) {
138 		dev_err(&left->dev, "failed to set column address: %d\n", err);
139 		return err;
140 	}
141 
142 	err = mipi_dsi_dcs_set_page_address(left, 0, mode->vdisplay - 1);
143 	if (err < 0) {
144 		dev_err(&left->dev, "failed to set page address: %d\n", err);
145 		return err;
146 	}
147 
148 	err = mipi_dsi_dcs_set_column_address(right, mode->hdisplay / 2,
149 					      mode->hdisplay - 1);
150 	if (err < 0) {
151 		dev_err(&right->dev, "failed to set column address: %d\n", err);
152 		return err;
153 	}
154 
155 	err = mipi_dsi_dcs_set_page_address(right, 0, mode->vdisplay - 1);
156 	if (err < 0) {
157 		dev_err(&right->dev, "failed to set page address: %d\n", err);
158 		return err;
159 	}
160 
161 	return 0;
162 }
163 
164 static int sharp_panel_prepare(struct drm_panel *panel)
165 {
166 	struct sharp_panel *sharp = to_sharp_panel(panel);
167 	u8 format = MIPI_DCS_PIXEL_FMT_24BIT;
168 	int err;
169 
170 	if (sharp->prepared)
171 		return 0;
172 
173 	err = regulator_enable(sharp->supply);
174 	if (err < 0)
175 		return err;
176 
177 	/*
178 	 * According to the datasheet, the panel needs around 10 ms to fully
179 	 * power up. At least another 120 ms is required before exiting sleep
180 	 * mode to make sure the panel is ready. Throw in another 20 ms for
181 	 * good measure.
182 	 */
183 	msleep(150);
184 
185 	err = mipi_dsi_dcs_exit_sleep_mode(sharp->link1);
186 	if (err < 0) {
187 		dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
188 		goto poweroff;
189 	}
190 
191 	/*
192 	 * The MIPI DCS specification mandates this delay only between the
193 	 * exit_sleep_mode and enter_sleep_mode commands, so it isn't strictly
194 	 * necessary here.
195 	 */
196 	/*
197 	msleep(120);
198 	*/
199 
200 	/* set left-right mode */
201 	err = sharp_panel_write(sharp, 0x1000, 0x2a);
202 	if (err < 0) {
203 		dev_err(panel->dev, "failed to set left-right mode: %d\n", err);
204 		goto poweroff;
205 	}
206 
207 	/* enable command mode */
208 	err = sharp_panel_write(sharp, 0x1001, 0x01);
209 	if (err < 0) {
210 		dev_err(panel->dev, "failed to enable command mode: %d\n", err);
211 		goto poweroff;
212 	}
213 
214 	err = mipi_dsi_dcs_set_pixel_format(sharp->link1, format);
215 	if (err < 0) {
216 		dev_err(panel->dev, "failed to set pixel format: %d\n", err);
217 		goto poweroff;
218 	}
219 
220 	/*
221 	 * TODO: The device supports both left-right and even-odd split
222 	 * configurations, but this driver currently supports only the left-
223 	 * right split. To support a different mode a mechanism needs to be
224 	 * put in place to communicate the configuration back to the DSI host
225 	 * controller.
226 	 */
227 	err = sharp_setup_symmetrical_split(sharp->link1, sharp->link2,
228 					    sharp->mode);
229 	if (err < 0) {
230 		dev_err(panel->dev, "failed to set up symmetrical split: %d\n",
231 			err);
232 		goto poweroff;
233 	}
234 
235 	err = mipi_dsi_dcs_set_display_on(sharp->link1);
236 	if (err < 0) {
237 		dev_err(panel->dev, "failed to set display on: %d\n", err);
238 		goto poweroff;
239 	}
240 
241 	sharp->prepared = true;
242 
243 	/* wait for 6 frames before continuing */
244 	sharp_wait_frames(sharp, 6);
245 
246 	return 0;
247 
248 poweroff:
249 	regulator_disable(sharp->supply);
250 	return err;
251 }
252 
253 static int sharp_panel_enable(struct drm_panel *panel)
254 {
255 	struct sharp_panel *sharp = to_sharp_panel(panel);
256 
257 	if (sharp->enabled)
258 		return 0;
259 
260 	backlight_enable(sharp->backlight);
261 
262 	sharp->enabled = true;
263 
264 	return 0;
265 }
266 
267 static const struct drm_display_mode default_mode = {
268 	.clock = 278000,
269 	.hdisplay = 2560,
270 	.hsync_start = 2560 + 128,
271 	.hsync_end = 2560 + 128 + 64,
272 	.htotal = 2560 + 128 + 64 + 64,
273 	.vdisplay = 1600,
274 	.vsync_start = 1600 + 4,
275 	.vsync_end = 1600 + 4 + 8,
276 	.vtotal = 1600 + 4 + 8 + 32,
277 	.vrefresh = 60,
278 };
279 
280 static int sharp_panel_get_modes(struct drm_panel *panel)
281 {
282 	struct drm_display_mode *mode;
283 
284 	mode = drm_mode_duplicate(panel->drm, &default_mode);
285 	if (!mode) {
286 		dev_err(panel->drm->dev, "failed to add mode %ux%ux@%u\n",
287 			default_mode.hdisplay, default_mode.vdisplay,
288 			default_mode.vrefresh);
289 		return -ENOMEM;
290 	}
291 
292 	drm_mode_set_name(mode);
293 
294 	drm_mode_probed_add(panel->connector, mode);
295 
296 	panel->connector->display_info.width_mm = 217;
297 	panel->connector->display_info.height_mm = 136;
298 
299 	return 1;
300 }
301 
302 static const struct drm_panel_funcs sharp_panel_funcs = {
303 	.disable = sharp_panel_disable,
304 	.unprepare = sharp_panel_unprepare,
305 	.prepare = sharp_panel_prepare,
306 	.enable = sharp_panel_enable,
307 	.get_modes = sharp_panel_get_modes,
308 };
309 
310 static const struct of_device_id sharp_of_match[] = {
311 	{ .compatible = "sharp,lq101r1sx01", },
312 	{ }
313 };
314 MODULE_DEVICE_TABLE(of, sharp_of_match);
315 
316 static int sharp_panel_add(struct sharp_panel *sharp)
317 {
318 	struct device *dev = &sharp->link1->dev;
319 
320 	sharp->mode = &default_mode;
321 
322 	sharp->supply = devm_regulator_get(&sharp->link1->dev, "power");
323 	if (IS_ERR(sharp->supply))
324 		return PTR_ERR(sharp->supply);
325 
326 	sharp->backlight = devm_of_find_backlight(dev);
327 
328 	if (IS_ERR(sharp->backlight))
329 		return PTR_ERR(sharp->backlight);
330 
331 	drm_panel_init(&sharp->base);
332 	sharp->base.funcs = &sharp_panel_funcs;
333 	sharp->base.dev = &sharp->link1->dev;
334 
335 	return drm_panel_add(&sharp->base);
336 }
337 
338 static void sharp_panel_del(struct sharp_panel *sharp)
339 {
340 	if (sharp->base.dev)
341 		drm_panel_remove(&sharp->base);
342 
343 	if (sharp->link2)
344 		put_device(&sharp->link2->dev);
345 }
346 
347 static int sharp_panel_probe(struct mipi_dsi_device *dsi)
348 {
349 	struct mipi_dsi_device *secondary = NULL;
350 	struct sharp_panel *sharp;
351 	struct device_node *np;
352 	int err;
353 
354 	dsi->lanes = 4;
355 	dsi->format = MIPI_DSI_FMT_RGB888;
356 	dsi->mode_flags = MIPI_DSI_MODE_LPM;
357 
358 	/* Find DSI-LINK1 */
359 	np = of_parse_phandle(dsi->dev.of_node, "link2", 0);
360 	if (np) {
361 		secondary = of_find_mipi_dsi_device_by_node(np);
362 		of_node_put(np);
363 
364 		if (!secondary)
365 			return -EPROBE_DEFER;
366 	}
367 
368 	/* register a panel for only the DSI-LINK1 interface */
369 	if (secondary) {
370 		sharp = devm_kzalloc(&dsi->dev, sizeof(*sharp), GFP_KERNEL);
371 		if (!sharp) {
372 			put_device(&secondary->dev);
373 			return -ENOMEM;
374 		}
375 
376 		mipi_dsi_set_drvdata(dsi, sharp);
377 
378 		sharp->link2 = secondary;
379 		sharp->link1 = dsi;
380 
381 		err = sharp_panel_add(sharp);
382 		if (err < 0) {
383 			put_device(&secondary->dev);
384 			return err;
385 		}
386 	}
387 
388 	err = mipi_dsi_attach(dsi);
389 	if (err < 0) {
390 		if (secondary)
391 			sharp_panel_del(sharp);
392 
393 		return err;
394 	}
395 
396 	return 0;
397 }
398 
399 static int sharp_panel_remove(struct mipi_dsi_device *dsi)
400 {
401 	struct sharp_panel *sharp = mipi_dsi_get_drvdata(dsi);
402 	int err;
403 
404 	/* only detach from host for the DSI-LINK2 interface */
405 	if (!sharp) {
406 		mipi_dsi_detach(dsi);
407 		return 0;
408 	}
409 
410 	err = sharp_panel_disable(&sharp->base);
411 	if (err < 0)
412 		dev_err(&dsi->dev, "failed to disable panel: %d\n", err);
413 
414 	err = mipi_dsi_detach(dsi);
415 	if (err < 0)
416 		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);
417 
418 	sharp_panel_del(sharp);
419 
420 	return 0;
421 }
422 
423 static void sharp_panel_shutdown(struct mipi_dsi_device *dsi)
424 {
425 	struct sharp_panel *sharp = mipi_dsi_get_drvdata(dsi);
426 
427 	/* nothing to do for DSI-LINK2 */
428 	if (!sharp)
429 		return;
430 
431 	sharp_panel_disable(&sharp->base);
432 }
433 
434 static struct mipi_dsi_driver sharp_panel_driver = {
435 	.driver = {
436 		.name = "panel-sharp-lq101r1sx01",
437 		.of_match_table = sharp_of_match,
438 	},
439 	.probe = sharp_panel_probe,
440 	.remove = sharp_panel_remove,
441 	.shutdown = sharp_panel_shutdown,
442 };
443 module_mipi_dsi_driver(sharp_panel_driver);
444 
445 MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>");
446 MODULE_DESCRIPTION("Sharp LQ101R1SX01 panel driver");
447 MODULE_LICENSE("GPL v2");
448