xref: /openbmc/linux/drivers/gpu/drm/mcde/mcde_drv.c (revision 745b7908)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Linus Walleij <linus.walleij@linaro.org>
4  * Parts of this file were based on the MCDE driver by Marcus Lorentzon
5  * (C) ST-Ericsson SA 2013
6  */
7 
8 /**
9  * DOC: ST-Ericsson MCDE Driver
10  *
11  * The MCDE (short for multi-channel display engine) is a graphics
12  * controller found in the Ux500 chipsets, such as NovaThor U8500.
13  * It was initially conceptualized by ST Microelectronics for the
14  * successor of the Nomadik line, STn8500 but productified in the
15  * ST-Ericsson U8500 where is was used for mass-market deployments
16  * in Android phones from Samsung and Sony Ericsson.
17  *
18  * It can do 1080p30 on SDTV CCIR656, DPI-2, DBI-2 or DSI for
19  * panels with or without frame buffering and can convert most
20  * input formats including most variants of RGB and YUV.
21  *
22  * The hardware has four display pipes, and the layout is a little
23  * bit like this::
24  *
25  *   Memory     -> Overlay -> Channel -> FIFO -> 8 formatters -> DSI/DPI
26  *   External      0..5       0..3       A,B,    6 x DSI         bridge
27  *   source 0..9                         C0,C1   2 x DPI
28  *
29  * FIFOs A and B are for LCD and HDMI while FIFO CO/C1 are for
30  * panels with embedded buffer.
31  * 6 of the formatters are for DSI, 3 pairs for VID/CMD respectively.
32  * 2 of the formatters are for DPI.
33  *
34  * Behind the formatters are the DSI or DPI ports that route to
35  * the external pins of the chip. As there are 3 DSI ports and one
36  * DPI port, it is possible to configure up to 4 display pipelines
37  * (effectively using channels 0..3) for concurrent use.
38  *
39  * In the current DRM/KMS setup, we use one external source, one overlay,
40  * one FIFO and one formatter which we connect to the simple DMA framebuffer
41  * helpers. We then provide a bridge to the DSI port, and on the DSI port
42  * bridge we connect hang a panel bridge or other bridge. This may be subject
43  * to change as we exploit more of the hardware capabilities.
44  *
45  * TODO:
46  *
47  * - Enabled damaged rectangles using drm_plane_enable_fb_damage_clips()
48  *   so we can selectively just transmit the damaged area to a
49  *   command-only display.
50  * - Enable mixing of more planes, possibly at the cost of moving away
51  *   from using the simple framebuffer pipeline.
52  * - Enable output to bridges such as the AV8100 HDMI encoder from
53  *   the DSI bridge.
54  */
55 
56 #include <linux/clk.h>
57 #include <linux/component.h>
58 #include <linux/dma-buf.h>
59 #include <linux/irq.h>
60 #include <linux/io.h>
61 #include <linux/module.h>
62 #include <linux/of_platform.h>
63 #include <linux/platform_device.h>
64 #include <linux/regulator/consumer.h>
65 #include <linux/slab.h>
66 #include <linux/delay.h>
67 
68 #include <drm/drm_atomic_helper.h>
69 #include <drm/drm_bridge.h>
70 #include <drm/drm_drv.h>
71 #include <drm/drm_fb_dma_helper.h>
72 #include <drm/drm_fbdev_dma.h>
73 #include <drm/drm_gem.h>
74 #include <drm/drm_gem_dma_helper.h>
75 #include <drm/drm_gem_framebuffer_helper.h>
76 #include <drm/drm_managed.h>
77 #include <drm/drm_of.h>
78 #include <drm/drm_probe_helper.h>
79 #include <drm/drm_panel.h>
80 #include <drm/drm_vblank.h>
81 
82 #include "mcde_drm.h"
83 
84 #define DRIVER_DESC	"DRM module for MCDE"
85 
86 #define MCDE_PID 0x000001FC
87 #define MCDE_PID_METALFIX_VERSION_SHIFT 0
88 #define MCDE_PID_METALFIX_VERSION_MASK 0x000000FF
89 #define MCDE_PID_DEVELOPMENT_VERSION_SHIFT 8
90 #define MCDE_PID_DEVELOPMENT_VERSION_MASK 0x0000FF00
91 #define MCDE_PID_MINOR_VERSION_SHIFT 16
92 #define MCDE_PID_MINOR_VERSION_MASK 0x00FF0000
93 #define MCDE_PID_MAJOR_VERSION_SHIFT 24
94 #define MCDE_PID_MAJOR_VERSION_MASK 0xFF000000
95 
96 static const struct drm_mode_config_funcs mcde_mode_config_funcs = {
97 	.fb_create = drm_gem_fb_create,
98 	.atomic_check = drm_atomic_helper_check,
99 	.atomic_commit = drm_atomic_helper_commit,
100 };
101 
102 static const struct drm_mode_config_helper_funcs mcde_mode_config_helpers = {
103 	/*
104 	 * Using this function is necessary to commit atomic updates
105 	 * that need the CRTC to be enabled before a commit, as is
106 	 * the case with e.g. DSI displays.
107 	 */
108 	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
109 };
110 
111 static irqreturn_t mcde_irq(int irq, void *data)
112 {
113 	struct mcde *mcde = data;
114 	u32 val;
115 
116 	val = readl(mcde->regs + MCDE_MISERR);
117 
118 	mcde_display_irq(mcde);
119 
120 	if (val)
121 		dev_info(mcde->dev, "some error IRQ\n");
122 	writel(val, mcde->regs + MCDE_RISERR);
123 
124 	return IRQ_HANDLED;
125 }
126 
127 static int mcde_modeset_init(struct drm_device *drm)
128 {
129 	struct drm_mode_config *mode_config;
130 	struct mcde *mcde = to_mcde(drm);
131 	int ret;
132 
133 	/*
134 	 * If no other bridge was found, check if we have a DPI panel or
135 	 * any other bridge connected directly to the MCDE DPI output.
136 	 * If a DSI bridge is found, DSI will take precedence.
137 	 *
138 	 * TODO: more elaborate bridge selection if we have more than one
139 	 * thing attached to the system.
140 	 */
141 	if (!mcde->bridge) {
142 		struct drm_panel *panel;
143 		struct drm_bridge *bridge;
144 
145 		ret = drm_of_find_panel_or_bridge(drm->dev->of_node,
146 						  0, 0, &panel, &bridge);
147 		if (ret) {
148 			dev_err(drm->dev,
149 				"Could not locate any output bridge or panel\n");
150 			return ret;
151 		}
152 		if (panel) {
153 			bridge = drm_panel_bridge_add_typed(panel,
154 					DRM_MODE_CONNECTOR_DPI);
155 			if (IS_ERR(bridge)) {
156 				dev_err(drm->dev,
157 					"Could not connect panel bridge\n");
158 				return PTR_ERR(bridge);
159 			}
160 		}
161 		mcde->dpi_output = true;
162 		mcde->bridge = bridge;
163 		mcde->flow_mode = MCDE_DPI_FORMATTER_FLOW;
164 	}
165 
166 	mode_config = &drm->mode_config;
167 	mode_config->funcs = &mcde_mode_config_funcs;
168 	mode_config->helper_private = &mcde_mode_config_helpers;
169 	/* This hardware can do 1080p */
170 	mode_config->min_width = 1;
171 	mode_config->max_width = 1920;
172 	mode_config->min_height = 1;
173 	mode_config->max_height = 1080;
174 
175 	ret = drm_vblank_init(drm, 1);
176 	if (ret) {
177 		dev_err(drm->dev, "failed to init vblank\n");
178 		return ret;
179 	}
180 
181 	ret = mcde_display_init(drm);
182 	if (ret) {
183 		dev_err(drm->dev, "failed to init display\n");
184 		return ret;
185 	}
186 
187 	/* Attach the bridge. */
188 	ret = drm_simple_display_pipe_attach_bridge(&mcde->pipe,
189 						    mcde->bridge);
190 	if (ret) {
191 		dev_err(drm->dev, "failed to attach display output bridge\n");
192 		return ret;
193 	}
194 
195 	drm_mode_config_reset(drm);
196 	drm_kms_helper_poll_init(drm);
197 
198 	return 0;
199 }
200 
201 DEFINE_DRM_GEM_DMA_FOPS(drm_fops);
202 
203 static const struct drm_driver mcde_drm_driver = {
204 	.driver_features =
205 		DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
206 	.ioctls = NULL,
207 	.fops = &drm_fops,
208 	.name = "mcde",
209 	.desc = DRIVER_DESC,
210 	.date = "20180529",
211 	.major = 1,
212 	.minor = 0,
213 	.patchlevel = 0,
214 	DRM_GEM_DMA_DRIVER_OPS,
215 };
216 
217 static int mcde_drm_bind(struct device *dev)
218 {
219 	struct drm_device *drm = dev_get_drvdata(dev);
220 	int ret;
221 
222 	ret = drmm_mode_config_init(drm);
223 	if (ret)
224 		return ret;
225 
226 	ret = component_bind_all(drm->dev, drm);
227 	if (ret) {
228 		dev_err(dev, "can't bind component devices\n");
229 		return ret;
230 	}
231 
232 	ret = mcde_modeset_init(drm);
233 	if (ret)
234 		goto unbind;
235 
236 	ret = drm_dev_register(drm, 0);
237 	if (ret < 0)
238 		goto unbind;
239 
240 	drm_fbdev_dma_setup(drm, 32);
241 
242 	return 0;
243 
244 unbind:
245 	component_unbind_all(drm->dev, drm);
246 	return ret;
247 }
248 
249 static void mcde_drm_unbind(struct device *dev)
250 {
251 	struct drm_device *drm = dev_get_drvdata(dev);
252 
253 	drm_dev_unregister(drm);
254 	drm_atomic_helper_shutdown(drm);
255 	component_unbind_all(drm->dev, drm);
256 }
257 
258 static const struct component_master_ops mcde_drm_comp_ops = {
259 	.bind = mcde_drm_bind,
260 	.unbind = mcde_drm_unbind,
261 };
262 
263 static struct platform_driver *const mcde_component_drivers[] = {
264 	&mcde_dsi_driver,
265 };
266 
267 static int mcde_probe(struct platform_device *pdev)
268 {
269 	struct device *dev = &pdev->dev;
270 	struct drm_device *drm;
271 	struct mcde *mcde;
272 	struct component_match *match = NULL;
273 	u32 pid;
274 	int irq;
275 	int ret;
276 	int i;
277 
278 	mcde = devm_drm_dev_alloc(dev, &mcde_drm_driver, struct mcde, drm);
279 	if (IS_ERR(mcde))
280 		return PTR_ERR(mcde);
281 	drm = &mcde->drm;
282 	mcde->dev = dev;
283 	platform_set_drvdata(pdev, drm);
284 
285 	/* First obtain and turn on the main power */
286 	mcde->epod = devm_regulator_get(dev, "epod");
287 	if (IS_ERR(mcde->epod)) {
288 		ret = PTR_ERR(mcde->epod);
289 		dev_err(dev, "can't get EPOD regulator\n");
290 		return ret;
291 	}
292 	ret = regulator_enable(mcde->epod);
293 	if (ret) {
294 		dev_err(dev, "can't enable EPOD regulator\n");
295 		return ret;
296 	}
297 	mcde->vana = devm_regulator_get(dev, "vana");
298 	if (IS_ERR(mcde->vana)) {
299 		ret = PTR_ERR(mcde->vana);
300 		dev_err(dev, "can't get VANA regulator\n");
301 		goto regulator_epod_off;
302 	}
303 	ret = regulator_enable(mcde->vana);
304 	if (ret) {
305 		dev_err(dev, "can't enable VANA regulator\n");
306 		goto regulator_epod_off;
307 	}
308 	/*
309 	 * The vendor code uses ESRAM (onchip RAM) and need to activate
310 	 * the v-esram34 regulator, but we don't use that yet
311 	 */
312 
313 	/* Clock the silicon so we can access the registers */
314 	mcde->mcde_clk = devm_clk_get(dev, "mcde");
315 	if (IS_ERR(mcde->mcde_clk)) {
316 		dev_err(dev, "unable to get MCDE main clock\n");
317 		ret = PTR_ERR(mcde->mcde_clk);
318 		goto regulator_off;
319 	}
320 	ret = clk_prepare_enable(mcde->mcde_clk);
321 	if (ret) {
322 		dev_err(dev, "failed to enable MCDE main clock\n");
323 		goto regulator_off;
324 	}
325 	dev_info(dev, "MCDE clk rate %lu Hz\n", clk_get_rate(mcde->mcde_clk));
326 
327 	mcde->lcd_clk = devm_clk_get(dev, "lcd");
328 	if (IS_ERR(mcde->lcd_clk)) {
329 		dev_err(dev, "unable to get LCD clock\n");
330 		ret = PTR_ERR(mcde->lcd_clk);
331 		goto clk_disable;
332 	}
333 	mcde->hdmi_clk = devm_clk_get(dev, "hdmi");
334 	if (IS_ERR(mcde->hdmi_clk)) {
335 		dev_err(dev, "unable to get HDMI clock\n");
336 		ret = PTR_ERR(mcde->hdmi_clk);
337 		goto clk_disable;
338 	}
339 
340 	mcde->regs = devm_platform_ioremap_resource(pdev, 0);
341 	if (IS_ERR(mcde->regs)) {
342 		dev_err(dev, "no MCDE regs\n");
343 		ret = -EINVAL;
344 		goto clk_disable;
345 	}
346 
347 	irq = platform_get_irq(pdev, 0);
348 	if (irq < 0) {
349 		ret = irq;
350 		goto clk_disable;
351 	}
352 
353 	ret = devm_request_irq(dev, irq, mcde_irq, 0, "mcde", mcde);
354 	if (ret) {
355 		dev_err(dev, "failed to request irq %d\n", ret);
356 		goto clk_disable;
357 	}
358 
359 	/*
360 	 * Check hardware revision, we only support U8500v2 version
361 	 * as this was the only version used for mass market deployment,
362 	 * but surely you can add more versions if you have them and
363 	 * need them.
364 	 */
365 	pid = readl(mcde->regs + MCDE_PID);
366 	dev_info(dev, "found MCDE HW revision %d.%d (dev %d, metal fix %d)\n",
367 		 (pid & MCDE_PID_MAJOR_VERSION_MASK)
368 		 >> MCDE_PID_MAJOR_VERSION_SHIFT,
369 		 (pid & MCDE_PID_MINOR_VERSION_MASK)
370 		 >> MCDE_PID_MINOR_VERSION_SHIFT,
371 		 (pid & MCDE_PID_DEVELOPMENT_VERSION_MASK)
372 		 >> MCDE_PID_DEVELOPMENT_VERSION_SHIFT,
373 		 (pid & MCDE_PID_METALFIX_VERSION_MASK)
374 		 >> MCDE_PID_METALFIX_VERSION_SHIFT);
375 	if (pid != 0x03000800) {
376 		dev_err(dev, "unsupported hardware revision\n");
377 		ret = -ENODEV;
378 		goto clk_disable;
379 	}
380 
381 	/* Disable and clear any pending interrupts */
382 	mcde_display_disable_irqs(mcde);
383 	writel(0, mcde->regs + MCDE_IMSCERR);
384 	writel(0xFFFFFFFF, mcde->regs + MCDE_RISERR);
385 
386 	/* Spawn child devices for the DSI ports */
387 	devm_of_platform_populate(dev);
388 
389 	/* Create something that will match the subdrivers when we bind */
390 	for (i = 0; i < ARRAY_SIZE(mcde_component_drivers); i++) {
391 		struct device_driver *drv = &mcde_component_drivers[i]->driver;
392 		struct device *p = NULL, *d;
393 
394 		while ((d = platform_find_device_by_driver(p, drv))) {
395 			put_device(p);
396 			component_match_add(dev, &match, component_compare_dev, d);
397 			p = d;
398 		}
399 		put_device(p);
400 	}
401 	if (!match) {
402 		dev_err(dev, "no matching components\n");
403 		ret = -ENODEV;
404 		goto clk_disable;
405 	}
406 	if (IS_ERR(match)) {
407 		dev_err(dev, "could not create component match\n");
408 		ret = PTR_ERR(match);
409 		goto clk_disable;
410 	}
411 
412 	/*
413 	 * Perform an invasive reset of the MCDE and all blocks by
414 	 * cutting the power to the subsystem, then bring it back up
415 	 * later when we enable the display as a result of
416 	 * component_master_add_with_match().
417 	 */
418 	ret = regulator_disable(mcde->epod);
419 	if (ret) {
420 		dev_err(dev, "can't disable EPOD regulator\n");
421 		return ret;
422 	}
423 	/* Wait 50 ms so we are sure we cut the power */
424 	usleep_range(50000, 70000);
425 
426 	ret = component_master_add_with_match(&pdev->dev, &mcde_drm_comp_ops,
427 					      match);
428 	if (ret) {
429 		dev_err(dev, "failed to add component master\n");
430 		/*
431 		 * The EPOD regulator is already disabled at this point so some
432 		 * special errorpath code is needed
433 		 */
434 		clk_disable_unprepare(mcde->mcde_clk);
435 		regulator_disable(mcde->vana);
436 		return ret;
437 	}
438 
439 	return 0;
440 
441 clk_disable:
442 	clk_disable_unprepare(mcde->mcde_clk);
443 regulator_off:
444 	regulator_disable(mcde->vana);
445 regulator_epod_off:
446 	regulator_disable(mcde->epod);
447 	return ret;
448 
449 }
450 
451 static int mcde_remove(struct platform_device *pdev)
452 {
453 	struct drm_device *drm = platform_get_drvdata(pdev);
454 	struct mcde *mcde = to_mcde(drm);
455 
456 	component_master_del(&pdev->dev, &mcde_drm_comp_ops);
457 	clk_disable_unprepare(mcde->mcde_clk);
458 	regulator_disable(mcde->vana);
459 	regulator_disable(mcde->epod);
460 
461 	return 0;
462 }
463 
464 static const struct of_device_id mcde_of_match[] = {
465 	{
466 		.compatible = "ste,mcde",
467 	},
468 	{},
469 };
470 
471 static struct platform_driver mcde_driver = {
472 	.driver = {
473 		.name           = "mcde",
474 		.of_match_table = of_match_ptr(mcde_of_match),
475 	},
476 	.probe = mcde_probe,
477 	.remove = mcde_remove,
478 };
479 
480 static struct platform_driver *const component_drivers[] = {
481 	&mcde_dsi_driver,
482 };
483 
484 static int __init mcde_drm_register(void)
485 {
486 	int ret;
487 
488 	if (drm_firmware_drivers_only())
489 		return -ENODEV;
490 
491 	ret = platform_register_drivers(component_drivers,
492 					ARRAY_SIZE(component_drivers));
493 	if (ret)
494 		return ret;
495 
496 	return platform_driver_register(&mcde_driver);
497 }
498 
499 static void __exit mcde_drm_unregister(void)
500 {
501 	platform_unregister_drivers(component_drivers,
502 				    ARRAY_SIZE(component_drivers));
503 	platform_driver_unregister(&mcde_driver);
504 }
505 
506 module_init(mcde_drm_register);
507 module_exit(mcde_drm_unregister);
508 
509 MODULE_ALIAS("platform:mcde-drm");
510 MODULE_DESCRIPTION(DRIVER_DESC);
511 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
512 MODULE_LICENSE("GPL");
513