1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * R-Car SYSC Power management support
4 *
5 * Copyright (C) 2014 Magnus Damm
6 * Copyright (C) 2015-2017 Glider bvba
7 */
8
9 #include <linux/clk/renesas.h>
10 #include <linux/delay.h>
11 #include <linux/err.h>
12 #include <linux/mm.h>
13 #include <linux/of_address.h>
14 #include <linux/pm_domain.h>
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 #include <linux/io.h>
18 #include <linux/soc/renesas/rcar-sysc.h>
19
20 #include "rcar-sysc.h"
21
22 /* SYSC Common */
23 #define SYSCSR 0x00 /* SYSC Status Register */
24 #define SYSCISR 0x04 /* Interrupt Status Register */
25 #define SYSCISCR 0x08 /* Interrupt Status Clear Register */
26 #define SYSCIER 0x0c /* Interrupt Enable Register */
27 #define SYSCIMR 0x10 /* Interrupt Mask Register */
28
29 /* SYSC Status Register */
30 #define SYSCSR_PONENB 1 /* Ready for power resume requests */
31 #define SYSCSR_POFFENB 0 /* Ready for power shutoff requests */
32
33 /*
34 * Power Control Register Offsets inside the register block for each domain
35 * Note: The "CR" registers for ARM cores exist on H1 only
36 * Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
37 * Use PSCI on R-Car Gen3
38 */
39 #define PWRSR_OFFS 0x00 /* Power Status Register */
40 #define PWROFFCR_OFFS 0x04 /* Power Shutoff Control Register */
41 #define PWROFFSR_OFFS 0x08 /* Power Shutoff Status Register */
42 #define PWRONCR_OFFS 0x0c /* Power Resume Control Register */
43 #define PWRONSR_OFFS 0x10 /* Power Resume Status Register */
44 #define PWRER_OFFS 0x14 /* Power Shutoff/Resume Error */
45
46
47 #define SYSCSR_RETRIES 100
48 #define SYSCSR_DELAY_US 1
49
50 #define PWRER_RETRIES 100
51 #define PWRER_DELAY_US 1
52
53 #define SYSCISR_RETRIES 1000
54 #define SYSCISR_DELAY_US 1
55
56 #define RCAR_PD_ALWAYS_ON 32 /* Always-on power area */
57
58 struct rcar_sysc_ch {
59 u16 chan_offs;
60 u8 chan_bit;
61 u8 isr_bit;
62 };
63
64 static void __iomem *rcar_sysc_base;
65 static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
66 static u32 rcar_sysc_extmask_offs, rcar_sysc_extmask_val;
67
rcar_sysc_pwr_on_off(const struct rcar_sysc_ch * sysc_ch,bool on)68 static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on)
69 {
70 unsigned int sr_bit, reg_offs;
71 int k;
72
73 if (on) {
74 sr_bit = SYSCSR_PONENB;
75 reg_offs = PWRONCR_OFFS;
76 } else {
77 sr_bit = SYSCSR_POFFENB;
78 reg_offs = PWROFFCR_OFFS;
79 }
80
81 /* Wait until SYSC is ready to accept a power request */
82 for (k = 0; k < SYSCSR_RETRIES; k++) {
83 if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit))
84 break;
85 udelay(SYSCSR_DELAY_US);
86 }
87
88 if (k == SYSCSR_RETRIES)
89 return -EAGAIN;
90
91 /* Submit power shutoff or power resume request */
92 iowrite32(BIT(sysc_ch->chan_bit),
93 rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
94
95 return 0;
96 }
97
rcar_sysc_power(const struct rcar_sysc_ch * sysc_ch,bool on)98 static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on)
99 {
100 unsigned int isr_mask = BIT(sysc_ch->isr_bit);
101 unsigned int chan_mask = BIT(sysc_ch->chan_bit);
102 unsigned int status;
103 unsigned long flags;
104 int ret = 0;
105 int k;
106
107 spin_lock_irqsave(&rcar_sysc_lock, flags);
108
109 /*
110 * Mask external power requests for CPU or 3DG domains
111 */
112 if (rcar_sysc_extmask_val) {
113 iowrite32(rcar_sysc_extmask_val,
114 rcar_sysc_base + rcar_sysc_extmask_offs);
115 }
116
117 /*
118 * The interrupt source needs to be enabled, but masked, to prevent the
119 * CPU from receiving it.
120 */
121 iowrite32(ioread32(rcar_sysc_base + SYSCIMR) | isr_mask,
122 rcar_sysc_base + SYSCIMR);
123 iowrite32(ioread32(rcar_sysc_base + SYSCIER) | isr_mask,
124 rcar_sysc_base + SYSCIER);
125
126 iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
127
128 /* Submit power shutoff or resume request until it was accepted */
129 for (k = 0; k < PWRER_RETRIES; k++) {
130 ret = rcar_sysc_pwr_on_off(sysc_ch, on);
131 if (ret)
132 goto out;
133
134 status = ioread32(rcar_sysc_base +
135 sysc_ch->chan_offs + PWRER_OFFS);
136 if (!(status & chan_mask))
137 break;
138
139 udelay(PWRER_DELAY_US);
140 }
141
142 if (k == PWRER_RETRIES) {
143 ret = -EIO;
144 goto out;
145 }
146
147 /* Wait until the power shutoff or resume request has completed * */
148 for (k = 0; k < SYSCISR_RETRIES; k++) {
149 if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
150 break;
151 udelay(SYSCISR_DELAY_US);
152 }
153
154 if (k == SYSCISR_RETRIES)
155 ret = -EIO;
156
157 iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
158
159 out:
160 if (rcar_sysc_extmask_val)
161 iowrite32(0, rcar_sysc_base + rcar_sysc_extmask_offs);
162
163 spin_unlock_irqrestore(&rcar_sysc_lock, flags);
164
165 pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
166 sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
167 return ret;
168 }
169
rcar_sysc_power_is_off(const struct rcar_sysc_ch * sysc_ch)170 static bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch)
171 {
172 unsigned int st;
173
174 st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
175 if (st & BIT(sysc_ch->chan_bit))
176 return true;
177
178 return false;
179 }
180
181 struct rcar_sysc_pd {
182 struct generic_pm_domain genpd;
183 struct rcar_sysc_ch ch;
184 unsigned int flags;
185 char name[];
186 };
187
to_rcar_pd(struct generic_pm_domain * d)188 static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d)
189 {
190 return container_of(d, struct rcar_sysc_pd, genpd);
191 }
192
rcar_sysc_pd_power_off(struct generic_pm_domain * genpd)193 static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd)
194 {
195 struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
196
197 pr_debug("%s: %s\n", __func__, genpd->name);
198 return rcar_sysc_power(&pd->ch, false);
199 }
200
rcar_sysc_pd_power_on(struct generic_pm_domain * genpd)201 static int rcar_sysc_pd_power_on(struct generic_pm_domain *genpd)
202 {
203 struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
204
205 pr_debug("%s: %s\n", __func__, genpd->name);
206 return rcar_sysc_power(&pd->ch, true);
207 }
208
209 static bool has_cpg_mstp;
210
rcar_sysc_pd_setup(struct rcar_sysc_pd * pd)211 static int __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
212 {
213 struct generic_pm_domain *genpd = &pd->genpd;
214 const char *name = pd->genpd.name;
215 int error;
216
217 if (pd->flags & PD_CPU) {
218 /*
219 * This domain contains a CPU core and therefore it should
220 * only be turned off if the CPU is not in use.
221 */
222 pr_debug("PM domain %s contains %s\n", name, "CPU");
223 genpd->flags |= GENPD_FLAG_ALWAYS_ON;
224 } else if (pd->flags & PD_SCU) {
225 /*
226 * This domain contains an SCU and cache-controller, and
227 * therefore it should only be turned off if the CPU cores are
228 * not in use.
229 */
230 pr_debug("PM domain %s contains %s\n", name, "SCU");
231 genpd->flags |= GENPD_FLAG_ALWAYS_ON;
232 } else if (pd->flags & PD_NO_CR) {
233 /*
234 * This domain cannot be turned off.
235 */
236 genpd->flags |= GENPD_FLAG_ALWAYS_ON;
237 }
238
239 if (!(pd->flags & (PD_CPU | PD_SCU))) {
240 /* Enable Clock Domain for I/O devices */
241 genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
242 if (has_cpg_mstp) {
243 genpd->attach_dev = cpg_mstp_attach_dev;
244 genpd->detach_dev = cpg_mstp_detach_dev;
245 } else {
246 genpd->attach_dev = cpg_mssr_attach_dev;
247 genpd->detach_dev = cpg_mssr_detach_dev;
248 }
249 }
250
251 genpd->power_off = rcar_sysc_pd_power_off;
252 genpd->power_on = rcar_sysc_pd_power_on;
253
254 if (pd->flags & (PD_CPU | PD_NO_CR)) {
255 /* Skip CPUs (handled by SMP code) and areas without control */
256 pr_debug("%s: Not touching %s\n", __func__, genpd->name);
257 goto finalize;
258 }
259
260 if (!rcar_sysc_power_is_off(&pd->ch)) {
261 pr_debug("%s: %s is already powered\n", __func__, genpd->name);
262 goto finalize;
263 }
264
265 rcar_sysc_power(&pd->ch, true);
266
267 finalize:
268 error = pm_genpd_init(genpd, &simple_qos_governor, false);
269 if (error)
270 pr_err("Failed to init PM domain %s: %d\n", name, error);
271
272 return error;
273 }
274
275 static const struct of_device_id rcar_sysc_matches[] __initconst = {
276 #ifdef CONFIG_SYSC_R8A7742
277 { .compatible = "renesas,r8a7742-sysc", .data = &r8a7742_sysc_info },
278 #endif
279 #ifdef CONFIG_SYSC_R8A7743
280 { .compatible = "renesas,r8a7743-sysc", .data = &r8a7743_sysc_info },
281 /* RZ/G1N is identical to RZ/G2M w.r.t. power domains. */
282 { .compatible = "renesas,r8a7744-sysc", .data = &r8a7743_sysc_info },
283 #endif
284 #ifdef CONFIG_SYSC_R8A7745
285 { .compatible = "renesas,r8a7745-sysc", .data = &r8a7745_sysc_info },
286 #endif
287 #ifdef CONFIG_SYSC_R8A77470
288 { .compatible = "renesas,r8a77470-sysc", .data = &r8a77470_sysc_info },
289 #endif
290 #ifdef CONFIG_SYSC_R8A774A1
291 { .compatible = "renesas,r8a774a1-sysc", .data = &r8a774a1_sysc_info },
292 #endif
293 #ifdef CONFIG_SYSC_R8A774B1
294 { .compatible = "renesas,r8a774b1-sysc", .data = &r8a774b1_sysc_info },
295 #endif
296 #ifdef CONFIG_SYSC_R8A774C0
297 { .compatible = "renesas,r8a774c0-sysc", .data = &r8a774c0_sysc_info },
298 #endif
299 #ifdef CONFIG_SYSC_R8A774E1
300 { .compatible = "renesas,r8a774e1-sysc", .data = &r8a774e1_sysc_info },
301 #endif
302 #ifdef CONFIG_SYSC_R8A7779
303 { .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
304 #endif
305 #ifdef CONFIG_SYSC_R8A7790
306 { .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
307 #endif
308 #ifdef CONFIG_SYSC_R8A7791
309 { .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
310 /* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */
311 { .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info },
312 #endif
313 #ifdef CONFIG_SYSC_R8A7792
314 { .compatible = "renesas,r8a7792-sysc", .data = &r8a7792_sysc_info },
315 #endif
316 #ifdef CONFIG_SYSC_R8A7794
317 { .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
318 #endif
319 #ifdef CONFIG_SYSC_R8A7795
320 { .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info },
321 #endif
322 #ifdef CONFIG_SYSC_R8A77960
323 { .compatible = "renesas,r8a7796-sysc", .data = &r8a77960_sysc_info },
324 #endif
325 #ifdef CONFIG_SYSC_R8A77961
326 { .compatible = "renesas,r8a77961-sysc", .data = &r8a77961_sysc_info },
327 #endif
328 #ifdef CONFIG_SYSC_R8A77965
329 { .compatible = "renesas,r8a77965-sysc", .data = &r8a77965_sysc_info },
330 #endif
331 #ifdef CONFIG_SYSC_R8A77970
332 { .compatible = "renesas,r8a77970-sysc", .data = &r8a77970_sysc_info },
333 #endif
334 #ifdef CONFIG_SYSC_R8A77980
335 { .compatible = "renesas,r8a77980-sysc", .data = &r8a77980_sysc_info },
336 #endif
337 #ifdef CONFIG_SYSC_R8A77990
338 { .compatible = "renesas,r8a77990-sysc", .data = &r8a77990_sysc_info },
339 #endif
340 #ifdef CONFIG_SYSC_R8A77995
341 { .compatible = "renesas,r8a77995-sysc", .data = &r8a77995_sysc_info },
342 #endif
343 { /* sentinel */ }
344 };
345
346 struct rcar_pm_domains {
347 struct genpd_onecell_data onecell_data;
348 struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
349 };
350
351 static struct genpd_onecell_data *rcar_sysc_onecell_data;
352
rcar_sysc_pd_init(void)353 static int __init rcar_sysc_pd_init(void)
354 {
355 const struct rcar_sysc_info *info;
356 const struct of_device_id *match;
357 struct rcar_pm_domains *domains;
358 struct device_node *np;
359 void __iomem *base;
360 unsigned int i;
361 int error;
362
363 np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
364 if (!np)
365 return -ENODEV;
366
367 info = match->data;
368
369 if (info->init) {
370 error = info->init();
371 if (error)
372 goto out_put;
373 }
374
375 has_cpg_mstp = of_find_compatible_node(NULL, NULL,
376 "renesas,cpg-mstp-clocks");
377
378 base = of_iomap(np, 0);
379 if (!base) {
380 pr_warn("%pOF: Cannot map regs\n", np);
381 error = -ENOMEM;
382 goto out_put;
383 }
384
385 rcar_sysc_base = base;
386
387 /* Optional External Request Mask Register */
388 rcar_sysc_extmask_offs = info->extmask_offs;
389 rcar_sysc_extmask_val = info->extmask_val;
390
391 domains = kzalloc(sizeof(*domains), GFP_KERNEL);
392 if (!domains) {
393 error = -ENOMEM;
394 goto out_put;
395 }
396
397 domains->onecell_data.domains = domains->domains;
398 domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
399 rcar_sysc_onecell_data = &domains->onecell_data;
400
401 for (i = 0; i < info->num_areas; i++) {
402 const struct rcar_sysc_area *area = &info->areas[i];
403 struct rcar_sysc_pd *pd;
404
405 if (!area->name) {
406 /* Skip NULLified area */
407 continue;
408 }
409
410 pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
411 if (!pd) {
412 error = -ENOMEM;
413 goto out_put;
414 }
415
416 strcpy(pd->name, area->name);
417 pd->genpd.name = pd->name;
418 pd->ch.chan_offs = area->chan_offs;
419 pd->ch.chan_bit = area->chan_bit;
420 pd->ch.isr_bit = area->isr_bit;
421 pd->flags = area->flags;
422
423 error = rcar_sysc_pd_setup(pd);
424 if (error)
425 goto out_put;
426
427 domains->domains[area->isr_bit] = &pd->genpd;
428
429 if (area->parent < 0)
430 continue;
431
432 error = pm_genpd_add_subdomain(domains->domains[area->parent],
433 &pd->genpd);
434 if (error) {
435 pr_warn("Failed to add PM subdomain %s to parent %u\n",
436 area->name, area->parent);
437 goto out_put;
438 }
439 }
440
441 error = of_genpd_add_provider_onecell(np, &domains->onecell_data);
442
443 out_put:
444 of_node_put(np);
445 return error;
446 }
447 early_initcall(rcar_sysc_pd_init);
448
rcar_sysc_nullify(struct rcar_sysc_area * areas,unsigned int num_areas,u8 id)449 void __init rcar_sysc_nullify(struct rcar_sysc_area *areas,
450 unsigned int num_areas, u8 id)
451 {
452 unsigned int i;
453
454 for (i = 0; i < num_areas; i++)
455 if (areas[i].isr_bit == id) {
456 areas[i].name = NULL;
457 return;
458 }
459 }
460
461 #ifdef CONFIG_ARCH_R8A7779
rcar_sysc_power_cpu(unsigned int idx,bool on)462 static int rcar_sysc_power_cpu(unsigned int idx, bool on)
463 {
464 struct generic_pm_domain *genpd;
465 struct rcar_sysc_pd *pd;
466 unsigned int i;
467
468 if (!rcar_sysc_onecell_data)
469 return -ENODEV;
470
471 for (i = 0; i < rcar_sysc_onecell_data->num_domains; i++) {
472 genpd = rcar_sysc_onecell_data->domains[i];
473 if (!genpd)
474 continue;
475
476 pd = to_rcar_pd(genpd);
477 if (!(pd->flags & PD_CPU) || pd->ch.chan_bit != idx)
478 continue;
479
480 return rcar_sysc_power(&pd->ch, on);
481 }
482
483 return -ENOENT;
484 }
485
rcar_sysc_power_down_cpu(unsigned int cpu)486 int rcar_sysc_power_down_cpu(unsigned int cpu)
487 {
488 return rcar_sysc_power_cpu(cpu, false);
489 }
490
rcar_sysc_power_up_cpu(unsigned int cpu)491 int rcar_sysc_power_up_cpu(unsigned int cpu)
492 {
493 return rcar_sysc_power_cpu(cpu, true);
494 }
495 #endif /* CONFIG_ARCH_R8A7779 */
496
