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