xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_dpi.c (revision d236d361)
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.  On BCM2835, these can be routed out to GPIO0-27 with the
22  * ALT2 function.
23  */
24 
25 #include "drm_atomic_helper.h"
26 #include "drm_crtc_helper.h"
27 #include "drm_edid.h"
28 #include "drm_panel.h"
29 #include "linux/clk.h"
30 #include "linux/component.h"
31 #include "linux/of_graph.h"
32 #include "linux/of_platform.h"
33 #include "vc4_drv.h"
34 #include "vc4_regs.h"
35 
36 #define DPI_C			0x00
37 # define DPI_OUTPUT_ENABLE_MODE		BIT(16)
38 
39 /* The order field takes the incoming 24 bit RGB from the pixel valve
40  * and shuffles the 3 channels.
41  */
42 # define DPI_ORDER_MASK			VC4_MASK(15, 14)
43 # define DPI_ORDER_SHIFT		14
44 # define DPI_ORDER_RGB			0
45 # define DPI_ORDER_BGR			1
46 # define DPI_ORDER_GRB			2
47 # define DPI_ORDER_BRG			3
48 
49 /* The format field takes the ORDER-shuffled pixel valve data and
50  * formats it onto the output lines.
51  */
52 # define DPI_FORMAT_MASK		VC4_MASK(13, 11)
53 # define DPI_FORMAT_SHIFT		11
54 /* This define is named in the hardware, but actually just outputs 0. */
55 # define DPI_FORMAT_9BIT_666_RGB	0
56 /* Outputs 00000000rrrrrggggggbbbbb */
57 # define DPI_FORMAT_16BIT_565_RGB_1	1
58 /* Outputs 000rrrrr00gggggg000bbbbb */
59 # define DPI_FORMAT_16BIT_565_RGB_2	2
60 /* Outputs 00rrrrr000gggggg00bbbbb0 */
61 # define DPI_FORMAT_16BIT_565_RGB_3	3
62 /* Outputs 000000rrrrrrggggggbbbbbb */
63 # define DPI_FORMAT_18BIT_666_RGB_1	4
64 /* Outputs 00rrrrrr00gggggg00bbbbbb */
65 # define DPI_FORMAT_18BIT_666_RGB_2	5
66 /* Outputs rrrrrrrrggggggggbbbbbbbb */
67 # define DPI_FORMAT_24BIT_888_RGB	6
68 
69 /* Reverses the polarity of the corresponding signal */
70 # define DPI_PIXEL_CLK_INVERT		BIT(10)
71 # define DPI_HSYNC_INVERT		BIT(9)
72 # define DPI_VSYNC_INVERT		BIT(8)
73 # define DPI_OUTPUT_ENABLE_INVERT	BIT(7)
74 
75 /* Outputs the signal the falling clock edge instead of rising. */
76 # define DPI_HSYNC_NEGATE		BIT(6)
77 # define DPI_VSYNC_NEGATE		BIT(5)
78 # define DPI_OUTPUT_ENABLE_NEGATE	BIT(4)
79 
80 /* Disables the signal */
81 # define DPI_HSYNC_DISABLE		BIT(3)
82 # define DPI_VSYNC_DISABLE		BIT(2)
83 # define DPI_OUTPUT_ENABLE_DISABLE	BIT(1)
84 
85 /* Power gate to the device, full reset at 0 -> 1 transition */
86 # define DPI_ENABLE			BIT(0)
87 
88 /* All other registers besides DPI_C return the ID */
89 #define DPI_ID			0x04
90 # define DPI_ID_VALUE		0x00647069
91 
92 /* General DPI hardware state. */
93 struct vc4_dpi {
94 	struct platform_device *pdev;
95 
96 	struct drm_encoder *encoder;
97 	struct drm_connector *connector;
98 	struct drm_panel *panel;
99 
100 	void __iomem *regs;
101 
102 	struct clk *pixel_clock;
103 	struct clk *core_clock;
104 };
105 
106 #define DPI_READ(offset) readl(dpi->regs + (offset))
107 #define DPI_WRITE(offset, val) writel(val, dpi->regs + (offset))
108 
109 /* VC4 DPI encoder KMS struct */
110 struct vc4_dpi_encoder {
111 	struct vc4_encoder base;
112 	struct vc4_dpi *dpi;
113 };
114 
115 static inline struct vc4_dpi_encoder *
116 to_vc4_dpi_encoder(struct drm_encoder *encoder)
117 {
118 	return container_of(encoder, struct vc4_dpi_encoder, base.base);
119 }
120 
121 /* VC4 DPI connector KMS struct */
122 struct vc4_dpi_connector {
123 	struct drm_connector base;
124 	struct vc4_dpi *dpi;
125 
126 	/* Since the connector is attached to just the one encoder,
127 	 * this is the reference to it so we can do the best_encoder()
128 	 * hook.
129 	 */
130 	struct drm_encoder *encoder;
131 };
132 
133 static inline struct vc4_dpi_connector *
134 to_vc4_dpi_connector(struct drm_connector *connector)
135 {
136 	return container_of(connector, struct vc4_dpi_connector, base);
137 }
138 
139 #define DPI_REG(reg) { reg, #reg }
140 static const struct {
141 	u32 reg;
142 	const char *name;
143 } dpi_regs[] = {
144 	DPI_REG(DPI_C),
145 	DPI_REG(DPI_ID),
146 };
147 
148 #ifdef CONFIG_DEBUG_FS
149 int vc4_dpi_debugfs_regs(struct seq_file *m, void *unused)
150 {
151 	struct drm_info_node *node = (struct drm_info_node *)m->private;
152 	struct drm_device *dev = node->minor->dev;
153 	struct vc4_dev *vc4 = to_vc4_dev(dev);
154 	struct vc4_dpi *dpi = vc4->dpi;
155 	int i;
156 
157 	if (!dpi)
158 		return 0;
159 
160 	for (i = 0; i < ARRAY_SIZE(dpi_regs); i++) {
161 		seq_printf(m, "%s (0x%04x): 0x%08x\n",
162 			   dpi_regs[i].name, dpi_regs[i].reg,
163 			   DPI_READ(dpi_regs[i].reg));
164 	}
165 
166 	return 0;
167 }
168 #endif
169 
170 static enum drm_connector_status
171 vc4_dpi_connector_detect(struct drm_connector *connector, bool force)
172 {
173 	struct vc4_dpi_connector *vc4_connector =
174 		to_vc4_dpi_connector(connector);
175 	struct vc4_dpi *dpi = vc4_connector->dpi;
176 
177 	if (dpi->panel)
178 		return connector_status_connected;
179 	else
180 		return connector_status_disconnected;
181 }
182 
183 static void vc4_dpi_connector_destroy(struct drm_connector *connector)
184 {
185 	drm_connector_unregister(connector);
186 	drm_connector_cleanup(connector);
187 }
188 
189 static int vc4_dpi_connector_get_modes(struct drm_connector *connector)
190 {
191 	struct vc4_dpi_connector *vc4_connector =
192 		to_vc4_dpi_connector(connector);
193 	struct vc4_dpi *dpi = vc4_connector->dpi;
194 
195 	if (dpi->panel)
196 		return drm_panel_get_modes(dpi->panel);
197 
198 	return 0;
199 }
200 
201 static const struct drm_connector_funcs vc4_dpi_connector_funcs = {
202 	.dpms = drm_atomic_helper_connector_dpms,
203 	.detect = vc4_dpi_connector_detect,
204 	.fill_modes = drm_helper_probe_single_connector_modes,
205 	.destroy = vc4_dpi_connector_destroy,
206 	.reset = drm_atomic_helper_connector_reset,
207 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
208 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
209 };
210 
211 static const struct drm_connector_helper_funcs vc4_dpi_connector_helper_funcs = {
212 	.get_modes = vc4_dpi_connector_get_modes,
213 };
214 
215 static struct drm_connector *vc4_dpi_connector_init(struct drm_device *dev,
216 						    struct vc4_dpi *dpi)
217 {
218 	struct drm_connector *connector = NULL;
219 	struct vc4_dpi_connector *dpi_connector;
220 
221 	dpi_connector = devm_kzalloc(dev->dev, sizeof(*dpi_connector),
222 				     GFP_KERNEL);
223 	if (!dpi_connector)
224 		return ERR_PTR(-ENOMEM);
225 
226 	connector = &dpi_connector->base;
227 
228 	dpi_connector->encoder = dpi->encoder;
229 	dpi_connector->dpi = dpi;
230 
231 	drm_connector_init(dev, connector, &vc4_dpi_connector_funcs,
232 			   DRM_MODE_CONNECTOR_DPI);
233 	drm_connector_helper_add(connector, &vc4_dpi_connector_helper_funcs);
234 
235 	connector->polled = 0;
236 	connector->interlace_allowed = 0;
237 	connector->doublescan_allowed = 0;
238 
239 	drm_mode_connector_attach_encoder(connector, dpi->encoder);
240 
241 	return connector;
242 }
243 
244 static const struct drm_encoder_funcs vc4_dpi_encoder_funcs = {
245 	.destroy = drm_encoder_cleanup,
246 };
247 
248 static void vc4_dpi_encoder_disable(struct drm_encoder *encoder)
249 {
250 	struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
251 	struct vc4_dpi *dpi = vc4_encoder->dpi;
252 
253 	drm_panel_disable(dpi->panel);
254 
255 	clk_disable_unprepare(dpi->pixel_clock);
256 
257 	drm_panel_unprepare(dpi->panel);
258 }
259 
260 static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
261 {
262 	struct drm_display_mode *mode = &encoder->crtc->mode;
263 	struct vc4_dpi_encoder *vc4_encoder = to_vc4_dpi_encoder(encoder);
264 	struct vc4_dpi *dpi = vc4_encoder->dpi;
265 	u32 dpi_c = DPI_ENABLE | DPI_OUTPUT_ENABLE_MODE;
266 	int ret;
267 
268 	ret = drm_panel_prepare(dpi->panel);
269 	if (ret) {
270 		DRM_ERROR("Panel failed to prepare\n");
271 		return;
272 	}
273 
274 	if (dpi->connector->display_info.num_bus_formats) {
275 		u32 bus_format = dpi->connector->display_info.bus_formats[0];
276 
277 		switch (bus_format) {
278 		case MEDIA_BUS_FMT_RGB888_1X24:
279 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
280 					       DPI_FORMAT);
281 			break;
282 		case MEDIA_BUS_FMT_BGR888_1X24:
283 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
284 					       DPI_FORMAT);
285 			dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
286 			break;
287 		case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
288 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
289 					       DPI_FORMAT);
290 			break;
291 		case MEDIA_BUS_FMT_RGB666_1X18:
292 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_1,
293 					       DPI_FORMAT);
294 			break;
295 		case MEDIA_BUS_FMT_RGB565_1X16:
296 			dpi_c |= VC4_SET_FIELD(DPI_FORMAT_16BIT_565_RGB_3,
297 					       DPI_FORMAT);
298 			break;
299 		default:
300 			DRM_ERROR("Unknown media bus format %d\n", bus_format);
301 			break;
302 		}
303 	}
304 
305 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
306 		dpi_c |= DPI_HSYNC_INVERT;
307 	else if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
308 		dpi_c |= DPI_HSYNC_DISABLE;
309 
310 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
311 		dpi_c |= DPI_VSYNC_INVERT;
312 	else if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
313 		dpi_c |= DPI_VSYNC_DISABLE;
314 
315 	DPI_WRITE(DPI_C, dpi_c);
316 
317 	ret = clk_set_rate(dpi->pixel_clock, mode->clock * 1000);
318 	if (ret)
319 		DRM_ERROR("Failed to set clock rate: %d\n", ret);
320 
321 	ret = clk_prepare_enable(dpi->pixel_clock);
322 	if (ret)
323 		DRM_ERROR("Failed to set clock rate: %d\n", ret);
324 
325 	ret = drm_panel_enable(dpi->panel);
326 	if (ret) {
327 		DRM_ERROR("Panel failed to enable\n");
328 		drm_panel_unprepare(dpi->panel);
329 		return;
330 	}
331 }
332 
333 static bool vc4_dpi_encoder_mode_fixup(struct drm_encoder *encoder,
334 				       const struct drm_display_mode *mode,
335 				       struct drm_display_mode *adjusted_mode)
336 {
337 	if (adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE)
338 		return false;
339 
340 	return true;
341 }
342 
343 static const struct drm_encoder_helper_funcs vc4_dpi_encoder_helper_funcs = {
344 	.disable = vc4_dpi_encoder_disable,
345 	.enable = vc4_dpi_encoder_enable,
346 	.mode_fixup = vc4_dpi_encoder_mode_fixup,
347 };
348 
349 static const struct of_device_id vc4_dpi_dt_match[] = {
350 	{ .compatible = "brcm,bcm2835-dpi", .data = NULL },
351 	{}
352 };
353 
354 /* Walks the OF graph to find the panel node and then asks DRM to look
355  * up the panel.
356  */
357 static struct drm_panel *vc4_dpi_get_panel(struct device *dev)
358 {
359 	struct device_node *panel_node;
360 	struct device_node *np = dev->of_node;
361 	struct drm_panel *panel;
362 
363 	/* don't proceed if we have an endpoint but no panel_node tied to it */
364 	panel_node = of_graph_get_remote_node(np, 0, 0);
365 	if (!panel_node)
366 		return NULL;
367 
368 	panel = of_drm_find_panel(panel_node);
369 	of_node_put(panel_node);
370 
371 	return panel;
372 }
373 
374 static int vc4_dpi_bind(struct device *dev, struct device *master, void *data)
375 {
376 	struct platform_device *pdev = to_platform_device(dev);
377 	struct drm_device *drm = dev_get_drvdata(master);
378 	struct vc4_dev *vc4 = to_vc4_dev(drm);
379 	struct vc4_dpi *dpi;
380 	struct vc4_dpi_encoder *vc4_dpi_encoder;
381 	int ret;
382 
383 	dpi = devm_kzalloc(dev, sizeof(*dpi), GFP_KERNEL);
384 	if (!dpi)
385 		return -ENOMEM;
386 
387 	vc4_dpi_encoder = devm_kzalloc(dev, sizeof(*vc4_dpi_encoder),
388 				       GFP_KERNEL);
389 	if (!vc4_dpi_encoder)
390 		return -ENOMEM;
391 	vc4_dpi_encoder->base.type = VC4_ENCODER_TYPE_DPI;
392 	vc4_dpi_encoder->dpi = dpi;
393 	dpi->encoder = &vc4_dpi_encoder->base.base;
394 
395 	dpi->pdev = pdev;
396 	dpi->regs = vc4_ioremap_regs(pdev, 0);
397 	if (IS_ERR(dpi->regs))
398 		return PTR_ERR(dpi->regs);
399 
400 	if (DPI_READ(DPI_ID) != DPI_ID_VALUE) {
401 		dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
402 			DPI_READ(DPI_ID), DPI_ID_VALUE);
403 		return -ENODEV;
404 	}
405 
406 	dpi->core_clock = devm_clk_get(dev, "core");
407 	if (IS_ERR(dpi->core_clock)) {
408 		ret = PTR_ERR(dpi->core_clock);
409 		if (ret != -EPROBE_DEFER)
410 			DRM_ERROR("Failed to get core clock: %d\n", ret);
411 		return ret;
412 	}
413 	dpi->pixel_clock = devm_clk_get(dev, "pixel");
414 	if (IS_ERR(dpi->pixel_clock)) {
415 		ret = PTR_ERR(dpi->pixel_clock);
416 		if (ret != -EPROBE_DEFER)
417 			DRM_ERROR("Failed to get pixel clock: %d\n", ret);
418 		return ret;
419 	}
420 
421 	ret = clk_prepare_enable(dpi->core_clock);
422 	if (ret)
423 		DRM_ERROR("Failed to turn on core clock: %d\n", ret);
424 
425 	dpi->panel = vc4_dpi_get_panel(dev);
426 
427 	drm_encoder_init(drm, dpi->encoder, &vc4_dpi_encoder_funcs,
428 			 DRM_MODE_ENCODER_DPI, NULL);
429 	drm_encoder_helper_add(dpi->encoder, &vc4_dpi_encoder_helper_funcs);
430 
431 	dpi->connector = vc4_dpi_connector_init(drm, dpi);
432 	if (IS_ERR(dpi->connector)) {
433 		ret = PTR_ERR(dpi->connector);
434 		goto err_destroy_encoder;
435 	}
436 
437 	if (dpi->panel)
438 		drm_panel_attach(dpi->panel, dpi->connector);
439 
440 	dev_set_drvdata(dev, dpi);
441 
442 	vc4->dpi = dpi;
443 
444 	return 0;
445 
446 err_destroy_encoder:
447 	drm_encoder_cleanup(dpi->encoder);
448 	clk_disable_unprepare(dpi->core_clock);
449 	return ret;
450 }
451 
452 static void vc4_dpi_unbind(struct device *dev, struct device *master,
453 			   void *data)
454 {
455 	struct drm_device *drm = dev_get_drvdata(master);
456 	struct vc4_dev *vc4 = to_vc4_dev(drm);
457 	struct vc4_dpi *dpi = dev_get_drvdata(dev);
458 
459 	if (dpi->panel)
460 		drm_panel_detach(dpi->panel);
461 
462 	vc4_dpi_connector_destroy(dpi->connector);
463 	drm_encoder_cleanup(dpi->encoder);
464 
465 	clk_disable_unprepare(dpi->core_clock);
466 
467 	vc4->dpi = NULL;
468 }
469 
470 static const struct component_ops vc4_dpi_ops = {
471 	.bind   = vc4_dpi_bind,
472 	.unbind = vc4_dpi_unbind,
473 };
474 
475 static int vc4_dpi_dev_probe(struct platform_device *pdev)
476 {
477 	return component_add(&pdev->dev, &vc4_dpi_ops);
478 }
479 
480 static int vc4_dpi_dev_remove(struct platform_device *pdev)
481 {
482 	component_del(&pdev->dev, &vc4_dpi_ops);
483 	return 0;
484 }
485 
486 struct platform_driver vc4_dpi_driver = {
487 	.probe = vc4_dpi_dev_probe,
488 	.remove = vc4_dpi_dev_remove,
489 	.driver = {
490 		.name = "vc4_dpi",
491 		.of_match_table = vc4_dpi_dt_match,
492 	},
493 };
494