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