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->power_off = rcar_sysc_pd_power_off;
245 genpd->power_on = rcar_sysc_pd_power_on;
246
247 if (pd->flags & (PD_CPU | PD_NO_CR)) {
248 /* Skip CPUs (handled by SMP code) and areas without control */
249 pr_debug("%s: Not touching %s\n", __func__, genpd->name);
250 goto finalize;
251 }
252
253 if (!rcar_sysc_power_is_off(pd)) {
254 pr_debug("%s: %s is already powered\n", __func__, genpd->name);
255 goto finalize;
256 }
257
258 rcar_sysc_power(pd, true);
259
260 finalize:
261 error = pm_genpd_init(genpd, &simple_qos_governor, false);
262 if (error)
263 pr_err("Failed to init PM domain %s: %d\n", name, error);
264
265 return error;
266 }
267
268 static const struct of_device_id rcar_sysc_matches[] __initconst = {
269 #ifdef CONFIG_SYSC_R8A7742
270 { .compatible = "renesas,r8a7742-sysc", .data = &r8a7742_sysc_info },
271 #endif
272 #ifdef CONFIG_SYSC_R8A7743
273 { .compatible = "renesas,r8a7743-sysc", .data = &r8a7743_sysc_info },
274 /* RZ/G1N is identical to RZ/G2M w.r.t. power domains. */
275 { .compatible = "renesas,r8a7744-sysc", .data = &r8a7743_sysc_info },
276 #endif
277 #ifdef CONFIG_SYSC_R8A7745
278 { .compatible = "renesas,r8a7745-sysc", .data = &r8a7745_sysc_info },
279 #endif
280 #ifdef CONFIG_SYSC_R8A77470
281 { .compatible = "renesas,r8a77470-sysc", .data = &r8a77470_sysc_info },
282 #endif
283 #ifdef CONFIG_SYSC_R8A774A1
284 { .compatible = "renesas,r8a774a1-sysc", .data = &r8a774a1_sysc_info },
285 #endif
286 #ifdef CONFIG_SYSC_R8A774B1
287 { .compatible = "renesas,r8a774b1-sysc", .data = &r8a774b1_sysc_info },
288 #endif
289 #ifdef CONFIG_SYSC_R8A774C0
290 { .compatible = "renesas,r8a774c0-sysc", .data = &r8a774c0_sysc_info },
291 #endif
292 #ifdef CONFIG_SYSC_R8A774E1
293 { .compatible = "renesas,r8a774e1-sysc", .data = &r8a774e1_sysc_info },
294 #endif
295 #ifdef CONFIG_SYSC_R8A7779
296 { .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
297 #endif
298 #ifdef CONFIG_SYSC_R8A7790
299 { .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
300 #endif
301 #ifdef CONFIG_SYSC_R8A7791
302 { .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
303 /* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */
304 { .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info },
305 #endif
306 #ifdef CONFIG_SYSC_R8A7792
307 { .compatible = "renesas,r8a7792-sysc", .data = &r8a7792_sysc_info },
308 #endif
309 #ifdef CONFIG_SYSC_R8A7794
310 { .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
311 #endif
312 #ifdef CONFIG_SYSC_R8A7795
313 { .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info },
314 #endif
315 #ifdef CONFIG_SYSC_R8A77960
316 { .compatible = "renesas,r8a7796-sysc", .data = &r8a77960_sysc_info },
317 #endif
318 #ifdef CONFIG_SYSC_R8A77961
319 { .compatible = "renesas,r8a77961-sysc", .data = &r8a77961_sysc_info },
320 #endif
321 #ifdef CONFIG_SYSC_R8A77965
322 { .compatible = "renesas,r8a77965-sysc", .data = &r8a77965_sysc_info },
323 #endif
324 #ifdef CONFIG_SYSC_R8A77970
325 { .compatible = "renesas,r8a77970-sysc", .data = &r8a77970_sysc_info },
326 #endif
327 #ifdef CONFIG_SYSC_R8A77980
328 { .compatible = "renesas,r8a77980-sysc", .data = &r8a77980_sysc_info },
329 #endif
330 #ifdef CONFIG_SYSC_R8A77990
331 { .compatible = "renesas,r8a77990-sysc", .data = &r8a77990_sysc_info },
332 #endif
333 #ifdef CONFIG_SYSC_R8A77995
334 { .compatible = "renesas,r8a77995-sysc", .data = &r8a77995_sysc_info },
335 #endif
336 { /* sentinel */ }
337 };
338
339 struct rcar_pm_domains {
340 struct genpd_onecell_data onecell_data;
341 struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
342 };
343
344 static struct genpd_onecell_data *rcar_sysc_onecell_data;
345
rcar_sysc_pd_init(void)346 static int __init rcar_sysc_pd_init(void)
347 {
348 const struct rcar_sysc_info *info;
349 const struct of_device_id *match;
350 struct rcar_pm_domains *domains;
351 struct device_node *np;
352 void __iomem *base;
353 unsigned int i;
354 int error;
355
356 np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
357 if (!np)
358 return -ENODEV;
359
360 info = match->data;
361
362 if (info->init) {
363 error = info->init();
364 if (error)
365 goto out_put;
366 }
367
368 has_cpg_mstp = of_find_compatible_node(NULL, NULL,
369 "renesas,cpg-mstp-clocks");
370
371 base = of_iomap(np, 0);
372 if (!base) {
373 pr_warn("%pOF: Cannot map regs\n", np);
374 error = -ENOMEM;
375 goto out_put;
376 }
377
378 rcar_sysc_base = base;
379
380 /* Optional External Request Mask Register */
381 rcar_sysc_extmask_offs = info->extmask_offs;
382 rcar_sysc_extmask_val = info->extmask_val;
383
384 domains = kzalloc(sizeof(*domains), GFP_KERNEL);
385 if (!domains) {
386 error = -ENOMEM;
387 goto out_put;
388 }
389
390 domains->onecell_data.domains = domains->domains;
391 domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
392 rcar_sysc_onecell_data = &domains->onecell_data;
393
394 for (i = 0; i < info->num_areas; i++) {
395 const struct rcar_sysc_area *area = &info->areas[i];
396 struct rcar_sysc_pd *pd;
397 size_t n;
398
399 if (!area->name) {
400 /* Skip NULLified area */
401 continue;
402 }
403
404 n = strlen(area->name) + 1;
405 pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
406 if (!pd) {
407 error = -ENOMEM;
408 goto out_put;
409 }
410
411 memcpy(pd->name, area->name, n);
412 pd->genpd.name = pd->name;
413 pd->chan_offs = area->chan_offs;
414 pd->chan_bit = area->chan_bit;
415 pd->isr_bit = area->isr_bit;
416 pd->flags = area->flags;
417
418 error = rcar_sysc_pd_setup(pd);
419 if (error)
420 goto out_put;
421
422 domains->domains[area->isr_bit] = &pd->genpd;
423
424 if (area->parent < 0)
425 continue;
426
427 error = pm_genpd_add_subdomain(domains->domains[area->parent],
428 &pd->genpd);
429 if (error) {
430 pr_warn("Failed to add PM subdomain %s to parent %u\n",
431 area->name, area->parent);
432 goto out_put;
433 }
434 }
435
436 error = of_genpd_add_provider_onecell(np, &domains->onecell_data);
437 if (!error)
438 fwnode_dev_initialized(of_fwnode_handle(np), true);
439
440 out_put:
441 of_node_put(np);
442 return error;
443 }
444 early_initcall(rcar_sysc_pd_init);
445
446 #ifdef CONFIG_ARCH_R8A7779
rcar_sysc_power_cpu(unsigned int idx,bool on)447 static int rcar_sysc_power_cpu(unsigned int idx, bool on)
448 {
449 struct generic_pm_domain *genpd;
450 struct rcar_sysc_pd *pd;
451 unsigned int i;
452
453 if (!rcar_sysc_onecell_data)
454 return -ENODEV;
455
456 for (i = 0; i < rcar_sysc_onecell_data->num_domains; i++) {
457 genpd = rcar_sysc_onecell_data->domains[i];
458 if (!genpd)
459 continue;
460
461 pd = to_rcar_pd(genpd);
462 if (!(pd->flags & PD_CPU) || pd->chan_bit != idx)
463 continue;
464
465 return rcar_sysc_power(pd, on);
466 }
467
468 return -ENOENT;
469 }
470
rcar_sysc_power_down_cpu(unsigned int cpu)471 int rcar_sysc_power_down_cpu(unsigned int cpu)
472 {
473 return rcar_sysc_power_cpu(cpu, false);
474 }
475
rcar_sysc_power_up_cpu(unsigned int cpu)476 int rcar_sysc_power_up_cpu(unsigned int cpu)
477 {
478 return rcar_sysc_power_cpu(cpu, true);
479 }
480 #endif /* CONFIG_ARCH_R8A7779 */
481