xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_dpi.c (revision 4e1a33b1)
1 /*
2  * Copyright (C) 2016 Broadcom Limited
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License version 2 as published by
6  * the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 
17 /**
18  * DOC: VC4 DPI module
19  *
20  * The VC4 DPI hardware supports MIPI DPI type 4 and Nokia ViSSI
21  * signals, which are routed out to GPIO0-27 with the ALT2 function.
22  */
23 
24 #include "drm_atomic_helper.h"
25 #include "drm_crtc_helper.h"
26 #include "drm_edid.h"
27 #include "drm_panel.h"
28 #include "linux/clk.h"
29 #include "linux/component.h"
30 #include "linux/of_graph.h"
31 #include "linux/of_platform.h"
32 #include "vc4_drv.h"
33 #include "vc4_regs.h"
34 
35 #define DPI_C			0x00
36 # define DPI_OUTPUT_ENABLE_MODE		BIT(16)
37 
38 /* The order field takes the incoming 24 bit RGB from the pixel valve
39  * and shuffles the 3 channels.
40  */
41 # define DPI_ORDER_MASK			VC4_MASK(15, 14)
42 # define DPI_ORDER_SHIFT		14
43 # define DPI_ORDER_RGB			0
44 # define DPI_ORDER_BGR			1
45 # define DPI_ORDER_GRB			2
46 # define DPI_ORDER_BRG			3
47 
48 /* The format field takes the ORDER-shuffled pixel valve data and
49  * formats it onto the output lines.
50  */
51 # define DPI_FORMAT_MASK		VC4_MASK(13, 11)
52 # define DPI_FORMAT_SHIFT		11
53 /* This define is named in the hardware, but actually just outputs 0. */
54 # define DPI_FORMAT_9BIT_666_RGB	0
55 /* Outputs 00000000rrrrrggggggbbbbb */
56 # define DPI_FORMAT_16BIT_565_RGB_1	1
57 /* Outputs 000rrrrr00gggggg000bbbbb */
58 # define DPI_FORMAT_16BIT_565_RGB_2	2
59 /* Outputs 00rrrrr000gggggg00bbbbb0 */
60 # define DPI_FORMAT_16BIT_565_RGB_3	3
61 /* Outputs 000000rrrrrrggggggbbbbbb */
62 # define DPI_FORMAT_18BIT_666_RGB_1	4
63 /* Outputs 00rrrrrr00gggggg00bbbbbb */
64 # define DPI_FORMAT_18BIT_666_RGB_2	5
65 /* Outputs rrrrrrrrggggggggbbbbbbbb */
66 # define DPI_FORMAT_24BIT_888_RGB	6
67 
68 /* Reverses the polarity of the corresponding signal */
69 # define DPI_PIXEL_CLK_INVERT		BIT(10)
70 # define DPI_HSYNC_INVERT		BIT(9)
71 # define DPI_VSYNC_INVERT		BIT(8)
72 # define DPI_OUTPUT_ENABLE_INVERT	BIT(7)
73 
74 /* Outputs the signal the falling clock edge instead of rising. */
75 # define DPI_HSYNC_NEGATE		BIT(6)
76 # define DPI_VSYNC_NEGATE		BIT(5)
77 # define DPI_OUTPUT_ENABLE_NEGATE	BIT(4)
78 
79 /* Disables the signal */
80 # define DPI_HSYNC_DISABLE		BIT(3)
81 # define DPI_VSYNC_DISABLE		BIT(2)
82 # define DPI_OUTPUT_ENABLE_DISABLE	BIT(1)
83 
84 /* Power gate to the device, full reset at 0 -> 1 transition */
85 # define DPI_ENABLE			BIT(0)
86 
87 /* All other registers besides DPI_C return the ID */
88 #define DPI_ID			0x04
89 # define DPI_ID_VALUE		0x00647069
90 
91 /* General DPI hardware state. */
92 struct vc4_dpi {
93 	struct platform_device *pdev;
94 
95 	struct drm_encoder *encoder;
96 	struct drm_connector *connector;
97 	struct drm_panel *panel;
98 
99 	void __iomem *regs;
100 
101 	struct clk *pixel_clock;
102 	struct clk *core_clock;
103 };
104 
105 #define DPI_READ(offset) readl(dpi->regs + (offset))
106 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
107 
108 /* VC4 DPI encoder KMS struct */
109 struct vc4_dpi_encoder {
110 	struct vc4_encoder base;
111 	struct vc4_dpi *dpi;
112 };
113 
114 static inline struct vc4_dpi_encoder *
115 to_vc4_dpi_encoder(struct drm_encoder *encoder)
116 {
117 	return container_of(encoder, struct vc4_dpi_encoder, base.base);
118 }
119 
120 /* VC4 DPI connector KMS struct */
121 struct vc4_dpi_connector {
122 	struct drm_connector base;
123 	struct vc4_dpi *dpi;
124 
125 	/* Since the connector is attached to just the one encoder,
126 	 * this is the reference to it so we can do the best_encoder()
127 	 * hook.
128 	 */
129 	struct drm_encoder *encoder;
130 };
131 
132 static inline struct vc4_dpi_connector *
133 to_vc4_dpi_connector(struct drm_connector *connector)
134 {
135 	return container_of(connector, struct vc4_dpi_connector, base);
136 }
137 
138 #define DPI_REG(reg) { reg, #reg }
139 static const struct {
140 	u32 reg;
141 	const char *name;
142 } dpi_regs[] = {
143 	DPI_REG(DPI_C),
144 	DPI_REG(DPI_ID),
145 };
146 
147 static void vc4_dpi_dump_regs(struct vc4_dpi *dpi)
148 {
149 	int i;
150 
151 	for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
152 		DRM_INFO("0x%04x (%s): 0x%08x\n",
153 			 dpi_regs[i].reg, dpi_regs[i].name,
154 			 DPI_READ(dpi_regs[i].reg));
155 	}
156 }
157 
158 #ifdef CONFIG_DEBUG_FS
159 int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
160 {
161 	struct drm_info_node *node = (struct drm_info_node *)m->private;
162 	struct drm_device *dev = node->minor->dev;
163 	struct vc4_dev *vc4 = to_vc4_dev(dev);
164 	struct vc4_dpi *dpi = vc4->dpi;
165 	int i;
166 
167 	if (!dpi)
168 		return 0;
169 
170 	for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
171 		seq_printf(m, "%s (0x%04x): 0x%08x\n",
172 			   dpi_regs[i].name, dpi_regs[i].reg,
173 			   DPI_READ(dpi_regs[i].reg));
174 	}
175 
176 	return 0;
177 }
178 #endif
179 
180 static enum drm_connector_status
181 vc4_dpi_connector_detect(struct drm_connector *connector, bool force)
182 {
183 	struct vc4_dpi_connector *vc4_connector =
184 		to_vc4_dpi_connector(connector);
185 	struct vc4_dpi *dpi = vc4_connector->dpi;
186 
187 	if (dpi->panel)
188 		return connector_status_connected;
189 	else
190 		return connector_status_disconnected;
191 }
192 
193 static void vc4_dpi_connector_destroy(struct drm_connector *connector)
194 {
195 	drm_connector_unregister(connector);
196 	drm_connector_cleanup(connector);
197 }
198 
199 static int vc4_dpi_connector_get_modes(struct drm_connector *connector)
200 {
201 	struct vc4_dpi_connector *vc4_connector =
202 		to_vc4_dpi_connector(connector);
203 	struct vc4_dpi *dpi = vc4_connector->dpi;
204 
205 	if (dpi->panel)
206 		return drm_panel_get_modes(dpi->panel);
207 
208 	return 0;
209 }
210 
211 static const struct drm_connector_funcs vc4_dpi_connector_funcs = {
212 	.dpms = drm_atomic_helper_connector_dpms,
213 	.detect = vc4_dpi_connector_detect,
214 	.fill_modes = drm_helper_probe_single_connector_modes,
215 	.destroy = vc4_dpi_connector_destroy,
216 	.reset = drm_atomic_helper_connector_reset,
217 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
218 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
219 };
220 
221 static const struct drm_connector_helper_funcs vc4_dpi_connector_helper_funcs = {
222 	.get_modes = vc4_dpi_connector_get_modes,
223 };
224 
225 static struct drm_connector *vc4_dpi_connector_init(struct drm_device *dev,
226 						    struct vc4_dpi *dpi)
227 {
228 	struct drm_connector *connector = NULL;
229 	struct vc4_dpi_connector *dpi_connector;
230 
231 	dpi_connector = devm_kzalloc(dev->dev, sizeof(*dpi_connector),
232 				     GFP_KERNEL);
233 	if (!dpi_connector)
234 		return ERR_PTR(-ENOMEM);
235 
236 	connector = &dpi_connector->base;
237 
238 	dpi_connector->encoder = dpi->encoder;
239 	dpi_connector->dpi = dpi;
240 
241 	drm_connector_init(dev, connector, &vc4_dpi_connector_funcs,
242 			   DRM_MODE_CONNECTOR_DPI);
243 	drm_connector_helper_add(connector, &vc4_dpi_connector_helper_funcs);
244 
245 	connector->polled = 0;
246 	connector->interlace_allowed = 0;
247 	connector->doublescan_allowed = 0;
248 
249 	drm_mode_connector_attach_encoder(connector, dpi->encoder);
250 
251 	return connector;
252 }
253 
254 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
255 	.destroy = drm_encoder_cleanup,
256 };
257 
258 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
259 {
260 	struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
261 	struct vc4_dpi *dpi = vc4_encoder->dpi;
262 
263 	drm_panel_disable(dpi->panel);
264 
265 	clk_disable_unprepare(dpi->pixel_clock);
266 
267 	drm_panel_unprepare(dpi->panel);
268 }
269 
270 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
271 {
272 	struct drm_display_mode *mode = &encoder->crtc->mode;
273 	struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
274 	struct vc4_dpi *dpi = vc4_encoder->dpi;
275 	u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
276 	int ret;
277 
278 	ret = drm_panel_prepare(dpi->panel);
279 	if (ret) {
280 		DRM_ERROR("Panel failed to prepare\n");
281 		return;
282 	}
283 
284 	if (dpi->connector->display_info.num_bus_formats) {
285 		u32 bus_format = dpi->connector->display_info.bus_formats[0];
286 
287 		switch (bus_format) {
288 		case MEDIA_BUS_FMT_RGB888_1X24:
289 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
290 					       DPI_FORMAT);
291 			break;
292 		case MEDIA_BUS_FMT_BGR888_1X24:
293 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
294 					       DPI_FORMAT);
295 			dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
296 			break;
297 		case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
298 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
299 					       DPI_FORMAT);
300 			break;
301 		case MEDIA_BUS_FMT_RGB666_1X18:
302 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
303 					       DPI_FORMAT);
304 			break;
305 		case MEDIA_BUS_FMT_RGB565_1X16:
306 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
307 					       DPI_FORMAT);
308 			break;
309 		default:
310 			DRM_ERROR("Unknown media bus format %d\n", bus_format);
311 			break;
312 		}
313 	}
314 
315 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
316 		dpi_c |= DPI_HSYNC_INVERT;
317 	else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
318 		dpi_c |= DPI_HSYNC_DISABLE;
319 
320 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
321 		dpi_c |= DPI_VSYNC_INVERT;
322 	else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
323 		dpi_c |= DPI_VSYNC_DISABLE;
324 
325 	DPI_WRITE(DPI_C, dpi_c);
326 
327 	ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
328 	if (ret)
329 		DRM_ERROR("Failed to set clock rate: %d\n", ret);
330 
331 	ret = clk_prepare_enable(dpi->pixel_clock);
332 	if (ret)
333 		DRM_ERROR("Failed to set clock rate: %d\n", ret);
334 
335 	ret = drm_panel_enable(dpi->panel);
336 	if (ret) {
337 		DRM_ERROR("Panel failed to enable\n");
338 		drm_panel_unprepare(dpi->panel);
339 		return;
340 	}
341 }
342 
343 static bool vc4_dpi_encoder_mode_fixup(struct drm_encoder *encoder,
344 				       const struct drm_display_mode *mode,
345 				       struct drm_display_mode *adjusted_mode)
346 {
347 	if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
348 		return false;
349 
350 	return true;
351 }
352 
353 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
354 	.disable = vc4_dpi_encoder_disable,
355 	.enable = vc4_dpi_encoder_enable,
356 	.mode_fixup = vc4_dpi_encoder_mode_fixup,
357 };
358 
359 static const struct of_device_id vc4_dpi_dt_match[] = {
360 	{ .compatible = "brcm,bcm2835-dpi", .data = NULL },
361 	{}
362 };
363 
364 /* Walks the OF graph to find the panel node and then asks DRM to look
365  * up the panel.
366  */
367 static struct drm_panel *vc4_dpi_get_panel(struct device *dev)
368 {
369 	struct device_node *endpoint, *panel_node;
370 	struct device_node *np = dev->of_node;
371 	struct drm_panel *panel;
372 
373 	endpoint = of_graph_get_next_endpoint(np, NULL);
374 	if (!endpoint) {
375 		dev_err(dev, "no endpoint to fetch DPI panel\n");
376 		return NULL;
377 	}
378 
379 	/* don't proceed if we have an endpoint but no panel_node tied to it */
380 	panel_node = of_graph_get_remote_port_parent(endpoint);
381 	of_node_put(endpoint);
382 	if (!panel_node) {
383 		dev_err(dev, "no valid panel node\n");
384 		return NULL;
385 	}
386 
387 	panel = of_drm_find_panel(panel_node);
388 	of_node_put(panel_node);
389 
390 	return panel;
391 }
392 
393 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
394 {
395 	struct platform_device *pdev = to_platform_device(dev);
396 	struct drm_device *drm = dev_get_drvdata(master);
397 	struct vc4_dev *vc4 = to_vc4_dev(drm);
398 	struct vc4_dpi *dpi;
399 	struct vc4_dpi_encoder *vc4_dpi_encoder;
400 	int ret;
401 
402 	dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
403 	if (!dpi)
404 		return -ENOMEM;
405 
406 	vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
407 				       GFP_KERNEL);
408 	if (!vc4_dpi_encoder)
409 		return -ENOMEM;
410 	vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
411 	vc4_dpi_encoder->dpi = dpi;
412 	dpi->encoder = &vc4_dpi_encoder->base.base;
413 
414 	dpi->pdev = pdev;
415 	dpi->regs = vc4_ioremap_regs(pdev, 0);
416 	if (IS_ERR(dpi->regs))
417 		return PTR_ERR(dpi->regs);
418 
419 	vc4_dpi_dump_regs(dpi);
420 
421 	if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
422 		dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
423 			DPI_READ(DPI_ID), DPI_ID_VALUE);
424 		return -ENODEV;
425 	}
426 
427 	dpi->core_clock = devm_clk_get(dev, "core");
428 	if (IS_ERR(dpi->core_clock)) {
429 		ret = PTR_ERR(dpi->core_clock);
430 		if (ret != -EPROBE_DEFER)
431 			DRM_ERROR("Failed to get core clock: %d\n", ret);
432 		return ret;
433 	}
434 	dpi->pixel_clock = devm_clk_get(dev, "pixel");
435 	if (IS_ERR(dpi->pixel_clock)) {
436 		ret = PTR_ERR(dpi->pixel_clock);
437 		if (ret != -EPROBE_DEFER)
438 			DRM_ERROR("Failed to get pixel clock: %d\n", ret);
439 		return ret;
440 	}
441 
442 	ret = clk_prepare_enable(dpi->core_clock);
443 	if (ret)
444 		DRM_ERROR("Failed to turn on core clock: %d\n", ret);
445 
446 	dpi->panel = vc4_dpi_get_panel(dev);
447 
448 	drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
449 			 DRM_MODE_ENCODER_DPI, NULL);
450 	drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
451 
452 	dpi->connector = vc4_dpi_connector_init(drm, dpi);
453 	if (IS_ERR(dpi->connector)) {
454 		ret = PTR_ERR(dpi->connector);
455 		goto err_destroy_encoder;
456 	}
457 
458 	if (dpi->panel)
459 		drm_panel_attach(dpi->panel, dpi->connector);
460 
461 	dev_set_drvdata(dev, dpi);
462 
463 	vc4->dpi = dpi;
464 
465 	return 0;
466 
467 err_destroy_encoder:
468 	drm_encoder_cleanup(dpi->encoder);
469 	clk_disable_unprepare(dpi->core_clock);
470 	return ret;
471 }
472 
473 static void vc4_dpi_unbind(struct device *dev, struct device *master,
474 			   void *data)
475 {
476 	struct drm_device *drm = dev_get_drvdata(master);
477 	struct vc4_dev *vc4 = to_vc4_dev(drm);
478 	struct vc4_dpi *dpi = dev_get_drvdata(dev);
479 
480 	if (dpi->panel)
481 		drm_panel_detach(dpi->panel);
482 
483 	vc4_dpi_connector_destroy(dpi->connector);
484 	drm_encoder_cleanup(dpi->encoder);
485 
486 	clk_disable_unprepare(dpi->core_clock);
487 
488 	vc4->dpi = NULL;
489 }
490 
491 static const struct component_ops vc4_dpi_ops = {
492 	.bind   = vc4_dpi_bind,
493 	.unbind = vc4_dpi_unbind,
494 };
495 
496 static int vc4_dpi_dev_probe(struct platform_device *pdev)
497 {
498 	return component_add(&pdev->dev, &vc4_dpi_ops);
499 }
500 
501 static int vc4_dpi_dev_remove(struct platform_device *pdev)
502 {
503 	component_del(&pdev->dev, &vc4_dpi_ops);
504 	return 0;
505 }
506 
507 struct platform_driver vc4_dpi_driver = {
508 	.probe = vc4_dpi_dev_probe,
509 	.remove = vc4_dpi_dev_remove,
510 	.driver = {
511 		.name = "vc4_dpi",
512 		.of_match_table = vc4_dpi_dt_match,
513 	},
514 };
515