xref: /linux/drivers/pmdomain/bcm/bcm2835-power.c (revision 34dc1baba215b826e454b8d19e4f24adbeb7d00d)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Power domain driver for Broadcom BCM2835
4  *
5  * Copyright (C) 2018 Broadcom
6  */
7 
8 #include <dt-bindings/soc/bcm2835-pm.h>
9 #include <linux/clk.h>
10 #include <linux/delay.h>
11 #include <linux/io.h>
12 #include <linux/mfd/bcm2835-pm.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_domain.h>
16 #include <linux/reset-controller.h>
17 #include <linux/types.h>
18 
19 #define PM_GNRIC                        0x00
20 #define PM_AUDIO                        0x04
21 #define PM_STATUS                       0x18
22 #define PM_RSTC				0x1c
23 #define PM_RSTS				0x20
24 #define PM_WDOG				0x24
25 #define PM_PADS0			0x28
26 #define PM_PADS2			0x2c
27 #define PM_PADS3			0x30
28 #define PM_PADS4			0x34
29 #define PM_PADS5			0x38
30 #define PM_PADS6			0x3c
31 #define PM_CAM0				0x44
32 #define PM_CAM0_LDOHPEN			BIT(2)
33 #define PM_CAM0_LDOLPEN			BIT(1)
34 #define PM_CAM0_CTRLEN			BIT(0)
35 
36 #define PM_CAM1				0x48
37 #define PM_CAM1_LDOHPEN			BIT(2)
38 #define PM_CAM1_LDOLPEN			BIT(1)
39 #define PM_CAM1_CTRLEN			BIT(0)
40 
41 #define PM_CCP2TX			0x4c
42 #define PM_CCP2TX_LDOEN			BIT(1)
43 #define PM_CCP2TX_CTRLEN		BIT(0)
44 
45 #define PM_DSI0				0x50
46 #define PM_DSI0_LDOHPEN			BIT(2)
47 #define PM_DSI0_LDOLPEN			BIT(1)
48 #define PM_DSI0_CTRLEN			BIT(0)
49 
50 #define PM_DSI1				0x54
51 #define PM_DSI1_LDOHPEN			BIT(2)
52 #define PM_DSI1_LDOLPEN			BIT(1)
53 #define PM_DSI1_CTRLEN			BIT(0)
54 
55 #define PM_HDMI				0x58
56 #define PM_HDMI_RSTDR			BIT(19)
57 #define PM_HDMI_LDOPD			BIT(1)
58 #define PM_HDMI_CTRLEN			BIT(0)
59 
60 #define PM_USB				0x5c
61 /* The power gates must be enabled with this bit before enabling the LDO in the
62  * USB block.
63  */
64 #define PM_USB_CTRLEN			BIT(0)
65 
66 #define PM_PXLDO			0x60
67 #define PM_PXBG				0x64
68 #define PM_DFT				0x68
69 #define PM_SMPS				0x6c
70 #define PM_XOSC				0x70
71 #define PM_SPAREW			0x74
72 #define PM_SPARER			0x78
73 #define PM_AVS_RSTDR			0x7c
74 #define PM_AVS_STAT			0x80
75 #define PM_AVS_EVENT			0x84
76 #define PM_AVS_INTEN			0x88
77 #define PM_DUMMY			0xfc
78 
79 #define PM_IMAGE			0x108
80 #define PM_GRAFX			0x10c
81 #define PM_PROC				0x110
82 #define PM_ENAB				BIT(12)
83 #define PM_ISPRSTN			BIT(8)
84 #define PM_H264RSTN			BIT(7)
85 #define PM_PERIRSTN			BIT(6)
86 #define PM_V3DRSTN			BIT(6)
87 #define PM_ISFUNC			BIT(5)
88 #define PM_MRDONE			BIT(4)
89 #define PM_MEMREP			BIT(3)
90 #define PM_ISPOW			BIT(2)
91 #define PM_POWOK			BIT(1)
92 #define PM_POWUP			BIT(0)
93 #define PM_INRUSH_SHIFT			13
94 #define PM_INRUSH_3_5_MA		0
95 #define PM_INRUSH_5_MA			1
96 #define PM_INRUSH_10_MA			2
97 #define PM_INRUSH_20_MA			3
98 #define PM_INRUSH_MASK			(3 << PM_INRUSH_SHIFT)
99 
100 #define PM_PASSWORD			0x5a000000
101 
102 #define PM_WDOG_TIME_SET		0x000fffff
103 #define PM_RSTC_WRCFG_CLR		0xffffffcf
104 #define PM_RSTS_HADWRH_SET		0x00000040
105 #define PM_RSTC_WRCFG_SET		0x00000030
106 #define PM_RSTC_WRCFG_FULL_RESET	0x00000020
107 #define PM_RSTC_RESET			0x00000102
108 
109 #define PM_READ(reg) readl(power->base + (reg))
110 #define PM_WRITE(reg, val) writel(PM_PASSWORD | (val), power->base + (reg))
111 
112 #define ASB_BRDG_VERSION                0x00
113 #define ASB_CPR_CTRL                    0x04
114 
115 #define ASB_V3D_S_CTRL			0x08
116 #define ASB_V3D_M_CTRL			0x0c
117 #define ASB_ISP_S_CTRL			0x10
118 #define ASB_ISP_M_CTRL			0x14
119 #define ASB_H264_S_CTRL			0x18
120 #define ASB_H264_M_CTRL			0x1c
121 
122 #define ASB_REQ_STOP                    BIT(0)
123 #define ASB_ACK                         BIT(1)
124 #define ASB_EMPTY                       BIT(2)
125 #define ASB_FULL                        BIT(3)
126 
127 #define ASB_AXI_BRDG_ID			0x20
128 
129 #define BCM2835_BRDG_ID			0x62726467
130 
131 struct bcm2835_power_domain {
132 	struct generic_pm_domain base;
133 	struct bcm2835_power *power;
134 	u32 domain;
135 	struct clk *clk;
136 };
137 
138 struct bcm2835_power {
139 	struct device		*dev;
140 	/* PM registers. */
141 	void __iomem		*base;
142 	/* AXI Async bridge registers. */
143 	void __iomem		*asb;
144 	/* RPiVid bridge registers. */
145 	void __iomem		*rpivid_asb;
146 
147 	struct genpd_onecell_data pd_xlate;
148 	struct bcm2835_power_domain domains[BCM2835_POWER_DOMAIN_COUNT];
149 	struct reset_controller_dev reset;
150 };
151 
152 static int bcm2835_asb_control(struct bcm2835_power *power, u32 reg, bool enable)
153 {
154 	void __iomem *base = power->asb;
155 	u64 start;
156 	u32 val;
157 
158 	switch (reg) {
159 	case 0:
160 		return 0;
161 	case ASB_V3D_S_CTRL:
162 	case ASB_V3D_M_CTRL:
163 		if (power->rpivid_asb)
164 			base = power->rpivid_asb;
165 		break;
166 	}
167 
168 	start = ktime_get_ns();
169 
170 	/* Enable the module's async AXI bridges. */
171 	if (enable) {
172 		val = readl(base + reg) & ~ASB_REQ_STOP;
173 	} else {
174 		val = readl(base + reg) | ASB_REQ_STOP;
175 	}
176 	writel(PM_PASSWORD | val, base + reg);
177 
178 	while (readl(base + reg) & ASB_ACK) {
179 		cpu_relax();
180 		if (ktime_get_ns() - start >= 1000)
181 			return -ETIMEDOUT;
182 	}
183 
184 	return 0;
185 }
186 
187 static int bcm2835_asb_enable(struct bcm2835_power *power, u32 reg)
188 {
189 	return bcm2835_asb_control(power, reg, true);
190 }
191 
192 static int bcm2835_asb_disable(struct bcm2835_power *power, u32 reg)
193 {
194 	return bcm2835_asb_control(power, reg, false);
195 }
196 
197 static int bcm2835_power_power_off(struct bcm2835_power_domain *pd, u32 pm_reg)
198 {
199 	struct bcm2835_power *power = pd->power;
200 
201 	/* We don't run this on BCM2711 */
202 	if (power->rpivid_asb)
203 		return 0;
204 
205 	/* Enable functional isolation */
206 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISFUNC);
207 
208 	/* Enable electrical isolation */
209 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
210 
211 	/* Open the power switches. */
212 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_POWUP);
213 
214 	return 0;
215 }
216 
217 static int bcm2835_power_power_on(struct bcm2835_power_domain *pd, u32 pm_reg)
218 {
219 	struct bcm2835_power *power = pd->power;
220 	struct device *dev = power->dev;
221 	u64 start;
222 	int ret;
223 	int inrush;
224 	bool powok;
225 
226 	/* We don't run this on BCM2711 */
227 	if (power->rpivid_asb)
228 		return 0;
229 
230 	/* If it was already powered on by the fw, leave it that way. */
231 	if (PM_READ(pm_reg) & PM_POWUP)
232 		return 0;
233 
234 	/* Enable power.  Allowing too much current at once may result
235 	 * in POWOK never getting set, so start low and ramp it up as
236 	 * necessary to succeed.
237 	 */
238 	powok = false;
239 	for (inrush = PM_INRUSH_3_5_MA; inrush <= PM_INRUSH_20_MA; inrush++) {
240 		PM_WRITE(pm_reg,
241 			 (PM_READ(pm_reg) & ~PM_INRUSH_MASK) |
242 			 (inrush << PM_INRUSH_SHIFT) |
243 			 PM_POWUP);
244 
245 		start = ktime_get_ns();
246 		while (!(powok = !!(PM_READ(pm_reg) & PM_POWOK))) {
247 			cpu_relax();
248 			if (ktime_get_ns() - start >= 3000)
249 				break;
250 		}
251 	}
252 	if (!powok) {
253 		dev_err(dev, "Timeout waiting for %s power OK\n",
254 			pd->base.name);
255 		ret = -ETIMEDOUT;
256 		goto err_disable_powup;
257 	}
258 
259 	/* Disable electrical isolation */
260 	PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISPOW);
261 
262 	/* Repair memory */
263 	PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_MEMREP);
264 	start = ktime_get_ns();
265 	while (!(PM_READ(pm_reg) & PM_MRDONE)) {
266 		cpu_relax();
267 		if (ktime_get_ns() - start >= 1000) {
268 			dev_err(dev, "Timeout waiting for %s memory repair\n",
269 				pd->base.name);
270 			ret = -ETIMEDOUT;
271 			goto err_disable_ispow;
272 		}
273 	}
274 
275 	/* Disable functional isolation */
276 	PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISFUNC);
277 
278 	return 0;
279 
280 err_disable_ispow:
281 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
282 err_disable_powup:
283 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~(PM_POWUP | PM_INRUSH_MASK));
284 	return ret;
285 }
286 
287 static int bcm2835_asb_power_on(struct bcm2835_power_domain *pd,
288 				u32 pm_reg,
289 				u32 asb_m_reg,
290 				u32 asb_s_reg,
291 				u32 reset_flags)
292 {
293 	struct bcm2835_power *power = pd->power;
294 	int ret;
295 
296 	ret = clk_prepare_enable(pd->clk);
297 	if (ret) {
298 		dev_err(power->dev, "Failed to enable clock for %s\n",
299 			pd->base.name);
300 		return ret;
301 	}
302 
303 	/* Wait 32 clocks for reset to propagate, 1 us will be enough */
304 	udelay(1);
305 
306 	clk_disable_unprepare(pd->clk);
307 
308 	/* Deassert the resets. */
309 	PM_WRITE(pm_reg, PM_READ(pm_reg) | reset_flags);
310 
311 	ret = clk_prepare_enable(pd->clk);
312 	if (ret) {
313 		dev_err(power->dev, "Failed to enable clock for %s\n",
314 			pd->base.name);
315 		goto err_enable_resets;
316 	}
317 
318 	ret = bcm2835_asb_enable(power, asb_m_reg);
319 	if (ret) {
320 		dev_err(power->dev, "Failed to enable ASB master for %s\n",
321 			pd->base.name);
322 		goto err_disable_clk;
323 	}
324 	ret = bcm2835_asb_enable(power, asb_s_reg);
325 	if (ret) {
326 		dev_err(power->dev, "Failed to enable ASB slave for %s\n",
327 			pd->base.name);
328 		goto err_disable_asb_master;
329 	}
330 
331 	return 0;
332 
333 err_disable_asb_master:
334 	bcm2835_asb_disable(power, asb_m_reg);
335 err_disable_clk:
336 	clk_disable_unprepare(pd->clk);
337 err_enable_resets:
338 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
339 	return ret;
340 }
341 
342 static int bcm2835_asb_power_off(struct bcm2835_power_domain *pd,
343 				 u32 pm_reg,
344 				 u32 asb_m_reg,
345 				 u32 asb_s_reg,
346 				 u32 reset_flags)
347 {
348 	struct bcm2835_power *power = pd->power;
349 	int ret;
350 
351 	ret = bcm2835_asb_disable(power, asb_s_reg);
352 	if (ret) {
353 		dev_warn(power->dev, "Failed to disable ASB slave for %s\n",
354 			 pd->base.name);
355 		return ret;
356 	}
357 	ret = bcm2835_asb_disable(power, asb_m_reg);
358 	if (ret) {
359 		dev_warn(power->dev, "Failed to disable ASB master for %s\n",
360 			 pd->base.name);
361 		bcm2835_asb_enable(power, asb_s_reg);
362 		return ret;
363 	}
364 
365 	clk_disable_unprepare(pd->clk);
366 
367 	/* Assert the resets. */
368 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
369 
370 	return 0;
371 }
372 
373 static int bcm2835_power_pd_power_on(struct generic_pm_domain *domain)
374 {
375 	struct bcm2835_power_domain *pd =
376 		container_of(domain, struct bcm2835_power_domain, base);
377 	struct bcm2835_power *power = pd->power;
378 
379 	switch (pd->domain) {
380 	case BCM2835_POWER_DOMAIN_GRAFX:
381 		return bcm2835_power_power_on(pd, PM_GRAFX);
382 
383 	case BCM2835_POWER_DOMAIN_GRAFX_V3D:
384 		return bcm2835_asb_power_on(pd, PM_GRAFX,
385 					    ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
386 					    PM_V3DRSTN);
387 
388 	case BCM2835_POWER_DOMAIN_IMAGE:
389 		return bcm2835_power_power_on(pd, PM_IMAGE);
390 
391 	case BCM2835_POWER_DOMAIN_IMAGE_PERI:
392 		return bcm2835_asb_power_on(pd, PM_IMAGE,
393 					    0, 0,
394 					    PM_PERIRSTN);
395 
396 	case BCM2835_POWER_DOMAIN_IMAGE_ISP:
397 		return bcm2835_asb_power_on(pd, PM_IMAGE,
398 					    ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
399 					    PM_ISPRSTN);
400 
401 	case BCM2835_POWER_DOMAIN_IMAGE_H264:
402 		return bcm2835_asb_power_on(pd, PM_IMAGE,
403 					    ASB_H264_M_CTRL, ASB_H264_S_CTRL,
404 					    PM_H264RSTN);
405 
406 	case BCM2835_POWER_DOMAIN_USB:
407 		PM_WRITE(PM_USB, PM_USB_CTRLEN);
408 		return 0;
409 
410 	case BCM2835_POWER_DOMAIN_DSI0:
411 		PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
412 		PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN | PM_DSI0_LDOHPEN);
413 		return 0;
414 
415 	case BCM2835_POWER_DOMAIN_DSI1:
416 		PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
417 		PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN | PM_DSI1_LDOHPEN);
418 		return 0;
419 
420 	case BCM2835_POWER_DOMAIN_CCP2TX:
421 		PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
422 		PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN | PM_CCP2TX_LDOEN);
423 		return 0;
424 
425 	case BCM2835_POWER_DOMAIN_HDMI:
426 		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_RSTDR);
427 		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_CTRLEN);
428 		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_LDOPD);
429 		usleep_range(100, 200);
430 		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_RSTDR);
431 		return 0;
432 
433 	default:
434 		dev_err(power->dev, "Invalid domain %d\n", pd->domain);
435 		return -EINVAL;
436 	}
437 }
438 
439 static int bcm2835_power_pd_power_off(struct generic_pm_domain *domain)
440 {
441 	struct bcm2835_power_domain *pd =
442 		container_of(domain, struct bcm2835_power_domain, base);
443 	struct bcm2835_power *power = pd->power;
444 
445 	switch (pd->domain) {
446 	case BCM2835_POWER_DOMAIN_GRAFX:
447 		return bcm2835_power_power_off(pd, PM_GRAFX);
448 
449 	case BCM2835_POWER_DOMAIN_GRAFX_V3D:
450 		return bcm2835_asb_power_off(pd, PM_GRAFX,
451 					     ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
452 					     PM_V3DRSTN);
453 
454 	case BCM2835_POWER_DOMAIN_IMAGE:
455 		return bcm2835_power_power_off(pd, PM_IMAGE);
456 
457 	case BCM2835_POWER_DOMAIN_IMAGE_PERI:
458 		return bcm2835_asb_power_off(pd, PM_IMAGE,
459 					     0, 0,
460 					     PM_PERIRSTN);
461 
462 	case BCM2835_POWER_DOMAIN_IMAGE_ISP:
463 		return bcm2835_asb_power_off(pd, PM_IMAGE,
464 					     ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
465 					     PM_ISPRSTN);
466 
467 	case BCM2835_POWER_DOMAIN_IMAGE_H264:
468 		return bcm2835_asb_power_off(pd, PM_IMAGE,
469 					     ASB_H264_M_CTRL, ASB_H264_S_CTRL,
470 					     PM_H264RSTN);
471 
472 	case BCM2835_POWER_DOMAIN_USB:
473 		PM_WRITE(PM_USB, 0);
474 		return 0;
475 
476 	case BCM2835_POWER_DOMAIN_DSI0:
477 		PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
478 		PM_WRITE(PM_DSI0, 0);
479 		return 0;
480 
481 	case BCM2835_POWER_DOMAIN_DSI1:
482 		PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
483 		PM_WRITE(PM_DSI1, 0);
484 		return 0;
485 
486 	case BCM2835_POWER_DOMAIN_CCP2TX:
487 		PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
488 		PM_WRITE(PM_CCP2TX, 0);
489 		return 0;
490 
491 	case BCM2835_POWER_DOMAIN_HDMI:
492 		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_LDOPD);
493 		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_CTRLEN);
494 		return 0;
495 
496 	default:
497 		dev_err(power->dev, "Invalid domain %d\n", pd->domain);
498 		return -EINVAL;
499 	}
500 }
501 
502 static int
503 bcm2835_init_power_domain(struct bcm2835_power *power,
504 			  int pd_xlate_index, const char *name)
505 {
506 	struct device *dev = power->dev;
507 	struct bcm2835_power_domain *dom = &power->domains[pd_xlate_index];
508 
509 	dom->clk = devm_clk_get(dev->parent, name);
510 	if (IS_ERR(dom->clk)) {
511 		int ret = PTR_ERR(dom->clk);
512 
513 		if (ret == -EPROBE_DEFER)
514 			return ret;
515 
516 		/* Some domains don't have a clk, so make sure that we
517 		 * don't deref an error pointer later.
518 		 */
519 		dom->clk = NULL;
520 	}
521 
522 	dom->base.name = name;
523 	dom->base.power_on = bcm2835_power_pd_power_on;
524 	dom->base.power_off = bcm2835_power_pd_power_off;
525 
526 	dom->domain = pd_xlate_index;
527 	dom->power = power;
528 
529 	/* XXX: on/off at boot? */
530 	pm_genpd_init(&dom->base, NULL, true);
531 
532 	power->pd_xlate.domains[pd_xlate_index] = &dom->base;
533 
534 	return 0;
535 }
536 
537 /** bcm2835_reset_reset - Resets a block that has a reset line in the
538  * PM block.
539  *
540  * The consumer of the reset controller must have the power domain up
541  * -- there's no reset ability with the power domain down.  To reset
542  * the sub-block, we just disable its access to memory through the
543  * ASB, reset, and re-enable.
544  */
545 static int bcm2835_reset_reset(struct reset_controller_dev *rcdev,
546 			       unsigned long id)
547 {
548 	struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
549 						   reset);
550 	struct bcm2835_power_domain *pd;
551 	int ret;
552 
553 	switch (id) {
554 	case BCM2835_RESET_V3D:
555 		pd = &power->domains[BCM2835_POWER_DOMAIN_GRAFX_V3D];
556 		break;
557 	case BCM2835_RESET_H264:
558 		pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_H264];
559 		break;
560 	case BCM2835_RESET_ISP:
561 		pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_ISP];
562 		break;
563 	default:
564 		dev_err(power->dev, "Bad reset id %ld\n", id);
565 		return -EINVAL;
566 	}
567 
568 	ret = bcm2835_power_pd_power_off(&pd->base);
569 	if (ret)
570 		return ret;
571 
572 	return bcm2835_power_pd_power_on(&pd->base);
573 }
574 
575 static int bcm2835_reset_status(struct reset_controller_dev *rcdev,
576 				unsigned long id)
577 {
578 	struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
579 						   reset);
580 
581 	switch (id) {
582 	case BCM2835_RESET_V3D:
583 		return !PM_READ(PM_GRAFX & PM_V3DRSTN);
584 	case BCM2835_RESET_H264:
585 		return !PM_READ(PM_IMAGE & PM_H264RSTN);
586 	case BCM2835_RESET_ISP:
587 		return !PM_READ(PM_IMAGE & PM_ISPRSTN);
588 	default:
589 		return -EINVAL;
590 	}
591 }
592 
593 static const struct reset_control_ops bcm2835_reset_ops = {
594 	.reset = bcm2835_reset_reset,
595 	.status = bcm2835_reset_status,
596 };
597 
598 static const char *const power_domain_names[] = {
599 	[BCM2835_POWER_DOMAIN_GRAFX] = "grafx",
600 	[BCM2835_POWER_DOMAIN_GRAFX_V3D] = "v3d",
601 
602 	[BCM2835_POWER_DOMAIN_IMAGE] = "image",
603 	[BCM2835_POWER_DOMAIN_IMAGE_PERI] = "peri_image",
604 	[BCM2835_POWER_DOMAIN_IMAGE_H264] = "h264",
605 	[BCM2835_POWER_DOMAIN_IMAGE_ISP] = "isp",
606 
607 	[BCM2835_POWER_DOMAIN_USB] = "usb",
608 	[BCM2835_POWER_DOMAIN_DSI0] = "dsi0",
609 	[BCM2835_POWER_DOMAIN_DSI1] = "dsi1",
610 	[BCM2835_POWER_DOMAIN_CAM0] = "cam0",
611 	[BCM2835_POWER_DOMAIN_CAM1] = "cam1",
612 	[BCM2835_POWER_DOMAIN_CCP2TX] = "ccp2tx",
613 	[BCM2835_POWER_DOMAIN_HDMI] = "hdmi",
614 };
615 
616 static int bcm2835_power_probe(struct platform_device *pdev)
617 {
618 	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
619 	struct device *dev = &pdev->dev;
620 	struct bcm2835_power *power;
621 	static const struct {
622 		int parent, child;
623 	} domain_deps[] = {
624 		{ BCM2835_POWER_DOMAIN_GRAFX, BCM2835_POWER_DOMAIN_GRAFX_V3D },
625 		{ BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_PERI },
626 		{ BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_H264 },
627 		{ BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_ISP },
628 		{ BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_USB },
629 		{ BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM0 },
630 		{ BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM1 },
631 	};
632 	int ret = 0, i;
633 	u32 id;
634 
635 	power = devm_kzalloc(dev, sizeof(*power), GFP_KERNEL);
636 	if (!power)
637 		return -ENOMEM;
638 	platform_set_drvdata(pdev, power);
639 
640 	power->dev = dev;
641 	power->base = pm->base;
642 	power->asb = pm->asb;
643 	power->rpivid_asb = pm->rpivid_asb;
644 
645 	id = readl(power->asb + ASB_AXI_BRDG_ID);
646 	if (id != BCM2835_BRDG_ID /* "BRDG" */) {
647 		dev_err(dev, "ASB register ID returned 0x%08x\n", id);
648 		return -ENODEV;
649 	}
650 
651 	if (power->rpivid_asb) {
652 		id = readl(power->rpivid_asb + ASB_AXI_BRDG_ID);
653 		if (id != BCM2835_BRDG_ID /* "BRDG" */) {
654 			dev_err(dev, "RPiVid ASB register ID returned 0x%08x\n",
655 				     id);
656 			return -ENODEV;
657 		}
658 	}
659 
660 	power->pd_xlate.domains = devm_kcalloc(dev,
661 					       ARRAY_SIZE(power_domain_names),
662 					       sizeof(*power->pd_xlate.domains),
663 					       GFP_KERNEL);
664 	if (!power->pd_xlate.domains)
665 		return -ENOMEM;
666 
667 	power->pd_xlate.num_domains = ARRAY_SIZE(power_domain_names);
668 
669 	for (i = 0; i < ARRAY_SIZE(power_domain_names); i++) {
670 		ret = bcm2835_init_power_domain(power, i, power_domain_names[i]);
671 		if (ret)
672 			goto fail;
673 	}
674 
675 	for (i = 0; i < ARRAY_SIZE(domain_deps); i++) {
676 		pm_genpd_add_subdomain(&power->domains[domain_deps[i].parent].base,
677 				       &power->domains[domain_deps[i].child].base);
678 	}
679 
680 	power->reset.owner = THIS_MODULE;
681 	power->reset.nr_resets = BCM2835_RESET_COUNT;
682 	power->reset.ops = &bcm2835_reset_ops;
683 	power->reset.of_node = dev->parent->of_node;
684 
685 	ret = devm_reset_controller_register(dev, &power->reset);
686 	if (ret)
687 		goto fail;
688 
689 	of_genpd_add_provider_onecell(dev->parent->of_node, &power->pd_xlate);
690 
691 	dev_info(dev, "Broadcom BCM2835 power domains driver");
692 	return 0;
693 
694 fail:
695 	for (i = 0; i < ARRAY_SIZE(power_domain_names); i++) {
696 		struct generic_pm_domain *dom = &power->domains[i].base;
697 
698 		if (dom->name)
699 			pm_genpd_remove(dom);
700 	}
701 	return ret;
702 }
703 
704 static struct platform_driver bcm2835_power_driver = {
705 	.probe		= bcm2835_power_probe,
706 	.driver = {
707 		.name =	"bcm2835-power",
708 	},
709 };
710 module_platform_driver(bcm2835_power_driver);
711 
712 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
713 MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM power domains and reset");
714