1 /*
2 * R-Car SYSC Power management support
3 *
4 * Copyright (C) 2014 Magnus Damm
5 * Copyright (C) 2015-2017 Glider bvba
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License. See the file "COPYING" in the main directory of this archive
9 * for more details.
10 */
11
12 #include <linux/clk/renesas.h>
13 #include <linux/delay.h>
14 #include <linux/err.h>
15 #include <linux/mm.h>
16 #include <linux/of_address.h>
17 #include <linux/pm_domain.h>
18 #include <linux/slab.h>
19 #include <linux/spinlock.h>
20 #include <linux/io.h>
21 #include <linux/soc/renesas/rcar-sysc.h>
22
23 #include "rcar-sysc.h"
24
25 /* SYSC Common */
26 #define SYSCSR 0x00 /* SYSC Status Register */
27 #define SYSCISR 0x04 /* Interrupt Status Register */
28 #define SYSCISCR 0x08 /* Interrupt Status Clear Register */
29 #define SYSCIER 0x0c /* Interrupt Enable Register */
30 #define SYSCIMR 0x10 /* Interrupt Mask Register */
31
32 /* SYSC Status Register */
33 #define SYSCSR_PONENB 1 /* Ready for power resume requests */
34 #define SYSCSR_POFFENB 0 /* Ready for power shutoff requests */
35
36 /*
37 * Power Control Register Offsets inside the register block for each domain
38 * Note: The "CR" registers for ARM cores exist on H1 only
39 * Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2
40 * Use PSCI on R-Car Gen3
41 */
42 #define PWRSR_OFFS 0x00 /* Power Status Register */
43 #define PWROFFCR_OFFS 0x04 /* Power Shutoff Control Register */
44 #define PWROFFSR_OFFS 0x08 /* Power Shutoff Status Register */
45 #define PWRONCR_OFFS 0x0c /* Power Resume Control Register */
46 #define PWRONSR_OFFS 0x10 /* Power Resume Status Register */
47 #define PWRER_OFFS 0x14 /* Power Shutoff/Resume Error */
48
49
50 #define SYSCSR_RETRIES 100
51 #define SYSCSR_DELAY_US 1
52
53 #define PWRER_RETRIES 100
54 #define PWRER_DELAY_US 1
55
56 #define SYSCISR_RETRIES 1000
57 #define SYSCISR_DELAY_US 1
58
59 #define RCAR_PD_ALWAYS_ON 32 /* Always-on power area */
60
61 struct rcar_sysc_ch {
62 u16 chan_offs;
63 u8 chan_bit;
64 u8 isr_bit;
65 };
66
67 static void __iomem *rcar_sysc_base;
68 static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
69
rcar_sysc_pwr_on_off(const struct rcar_sysc_ch * sysc_ch,bool on)70 static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on)
71 {
72 unsigned int sr_bit, reg_offs;
73 int k;
74
75 if (on) {
76 sr_bit = SYSCSR_PONENB;
77 reg_offs = PWRONCR_OFFS;
78 } else {
79 sr_bit = SYSCSR_POFFENB;
80 reg_offs = PWROFFCR_OFFS;
81 }
82
83 /* Wait until SYSC is ready to accept a power request */
84 for (k = 0; k < SYSCSR_RETRIES; k++) {
85 if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit))
86 break;
87 udelay(SYSCSR_DELAY_US);
88 }
89
90 if (k == SYSCSR_RETRIES)
91 return -EAGAIN;
92
93 /* Submit power shutoff or power resume request */
94 iowrite32(BIT(sysc_ch->chan_bit),
95 rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
96
97 return 0;
98 }
99
rcar_sysc_power(const struct rcar_sysc_ch * sysc_ch,bool on)100 static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on)
101 {
102 unsigned int isr_mask = BIT(sysc_ch->isr_bit);
103 unsigned int chan_mask = BIT(sysc_ch->chan_bit);
104 unsigned int status;
105 unsigned long flags;
106 int ret = 0;
107 int k;
108
109 spin_lock_irqsave(&rcar_sysc_lock, flags);
110
111 iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
112
113 /* Submit power shutoff or resume request until it was accepted */
114 for (k = 0; k < PWRER_RETRIES; k++) {
115 ret = rcar_sysc_pwr_on_off(sysc_ch, on);
116 if (ret)
117 goto out;
118
119 status = ioread32(rcar_sysc_base +
120 sysc_ch->chan_offs + PWRER_OFFS);
121 if (!(status & chan_mask))
122 break;
123
124 udelay(PWRER_DELAY_US);
125 }
126
127 if (k == PWRER_RETRIES) {
128 ret = -EIO;
129 goto out;
130 }
131
132 /* Wait until the power shutoff or resume request has completed * */
133 for (k = 0; k < SYSCISR_RETRIES; k++) {
134 if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
135 break;
136 udelay(SYSCISR_DELAY_US);
137 }
138
139 if (k == SYSCISR_RETRIES)
140 ret = -EIO;
141
142 iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
143
144 out:
145 spin_unlock_irqrestore(&rcar_sysc_lock, flags);
146
147 pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off",
148 sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
149 return ret;
150 }
151
rcar_sysc_power_down(const struct rcar_sysc_ch * sysc_ch)152 static int rcar_sysc_power_down(const struct rcar_sysc_ch *sysc_ch)
153 {
154 return rcar_sysc_power(sysc_ch, false);
155 }
156
rcar_sysc_power_up(const struct rcar_sysc_ch * sysc_ch)157 static int rcar_sysc_power_up(const struct rcar_sysc_ch *sysc_ch)
158 {
159 return rcar_sysc_power(sysc_ch, true);
160 }
161
rcar_sysc_power_is_off(const struct rcar_sysc_ch * sysc_ch)162 static bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch)
163 {
164 unsigned int st;
165
166 st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
167 if (st & BIT(sysc_ch->chan_bit))
168 return true;
169
170 return false;
171 }
172
173 struct rcar_sysc_pd {
174 struct generic_pm_domain genpd;
175 struct rcar_sysc_ch ch;
176 unsigned int flags;
177 char name[0];
178 };
179
to_rcar_pd(struct generic_pm_domain * d)180 static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d)
181 {
182 return container_of(d, struct rcar_sysc_pd, genpd);
183 }
184
rcar_sysc_pd_power_off(struct generic_pm_domain * genpd)185 static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd)
186 {
187 struct rcar_sysc_pd *pd = to_rcar_pd(genpd);
188
189 pr_debug("%s: %s\n", __func__, genpd->name);
190 return rcar_sysc_power_down(&pd->ch);
191 }
192
rcar_sysc_pd_power_on(struct generic_pm_domain * genpd)193 static int rcar_sysc_pd_power_on(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_up(&pd->ch);
199 }
200
201 static bool has_cpg_mstp;
202
rcar_sysc_pd_setup(struct rcar_sysc_pd * pd)203 static int __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
204 {
205 struct generic_pm_domain *genpd = &pd->genpd;
206 const char *name = pd->genpd.name;
207 struct dev_power_governor *gov = &simple_qos_governor;
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->ch)) {
254 pr_debug("%s: %s is already powered\n", __func__, genpd->name);
255 goto finalize;
256 }
257
258 rcar_sysc_power_up(&pd->ch);
259
260 finalize:
261 error = pm_genpd_init(genpd, gov, 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_R8A7743
270 { .compatible = "renesas,r8a7743-sysc", .data = &r8a7743_sysc_info },
271 #endif
272 #ifdef CONFIG_SYSC_R8A7745
273 { .compatible = "renesas,r8a7745-sysc", .data = &r8a7745_sysc_info },
274 #endif
275 #ifdef CONFIG_SYSC_R8A77470
276 { .compatible = "renesas,r8a77470-sysc", .data = &r8a77470_sysc_info },
277 #endif
278 #ifdef CONFIG_SYSC_R8A7779
279 { .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
280 #endif
281 #ifdef CONFIG_SYSC_R8A7790
282 { .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
283 #endif
284 #ifdef CONFIG_SYSC_R8A7791
285 { .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
286 /* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */
287 { .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info },
288 #endif
289 #ifdef CONFIG_SYSC_R8A7792
290 { .compatible = "renesas,r8a7792-sysc", .data = &r8a7792_sysc_info },
291 #endif
292 #ifdef CONFIG_SYSC_R8A7794
293 { .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
294 #endif
295 #ifdef CONFIG_SYSC_R8A7795
296 { .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info },
297 #endif
298 #ifdef CONFIG_SYSC_R8A7796
299 { .compatible = "renesas,r8a7796-sysc", .data = &r8a7796_sysc_info },
300 #endif
301 #ifdef CONFIG_SYSC_R8A77965
302 { .compatible = "renesas,r8a77965-sysc", .data = &r8a77965_sysc_info },
303 #endif
304 #ifdef CONFIG_SYSC_R8A77970
305 { .compatible = "renesas,r8a77970-sysc", .data = &r8a77970_sysc_info },
306 #endif
307 #ifdef CONFIG_SYSC_R8A77980
308 { .compatible = "renesas,r8a77980-sysc", .data = &r8a77980_sysc_info },
309 #endif
310 #ifdef CONFIG_SYSC_R8A77990
311 { .compatible = "renesas,r8a77990-sysc", .data = &r8a77990_sysc_info },
312 #endif
313 #ifdef CONFIG_SYSC_R8A77995
314 { .compatible = "renesas,r8a77995-sysc", .data = &r8a77995_sysc_info },
315 #endif
316 { /* sentinel */ }
317 };
318
319 struct rcar_pm_domains {
320 struct genpd_onecell_data onecell_data;
321 struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1];
322 };
323
324 static struct genpd_onecell_data *rcar_sysc_onecell_data;
325
rcar_sysc_pd_init(void)326 static int __init rcar_sysc_pd_init(void)
327 {
328 const struct rcar_sysc_info *info;
329 const struct of_device_id *match;
330 struct rcar_pm_domains *domains;
331 struct device_node *np;
332 u32 syscier, syscimr;
333 void __iomem *base;
334 unsigned int i;
335 int error;
336
337 np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match);
338 if (!np)
339 return -ENODEV;
340
341 info = match->data;
342
343 if (info->init) {
344 error = info->init();
345 if (error)
346 return error;
347 }
348
349 has_cpg_mstp = of_find_compatible_node(NULL, NULL,
350 "renesas,cpg-mstp-clocks");
351
352 base = of_iomap(np, 0);
353 if (!base) {
354 pr_warn("%pOF: Cannot map regs\n", np);
355 error = -ENOMEM;
356 goto out_put;
357 }
358
359 rcar_sysc_base = base;
360
361 domains = kzalloc(sizeof(*domains), GFP_KERNEL);
362 if (!domains) {
363 error = -ENOMEM;
364 goto out_put;
365 }
366
367 domains->onecell_data.domains = domains->domains;
368 domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains);
369 rcar_sysc_onecell_data = &domains->onecell_data;
370
371 for (i = 0, syscier = 0; i < info->num_areas; i++)
372 syscier |= BIT(info->areas[i].isr_bit);
373
374 /*
375 * Mask all interrupt sources to prevent the CPU from receiving them.
376 * Make sure not to clear reserved bits that were set before.
377 */
378 syscimr = ioread32(base + SYSCIMR);
379 syscimr |= syscier;
380 pr_debug("%pOF: syscimr = 0x%08x\n", np, syscimr);
381 iowrite32(syscimr, base + SYSCIMR);
382
383 /*
384 * SYSC needs all interrupt sources enabled to control power.
385 */
386 pr_debug("%pOF: syscier = 0x%08x\n", np, syscier);
387 iowrite32(syscier, base + SYSCIER);
388
389 /*
390 * First, create all PM domains
391 */
392 for (i = 0; i < info->num_areas; i++) {
393 const struct rcar_sysc_area *area = &info->areas[i];
394 struct rcar_sysc_pd *pd;
395
396 if (!area->name) {
397 /* Skip NULLified area */
398 continue;
399 }
400
401 pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
402 if (!pd) {
403 error = -ENOMEM;
404 goto out_put;
405 }
406
407 strcpy(pd->name, area->name);
408 pd->genpd.name = pd->name;
409 pd->ch.chan_offs = area->chan_offs;
410 pd->ch.chan_bit = area->chan_bit;
411 pd->ch.isr_bit = area->isr_bit;
412 pd->flags = area->flags;
413
414 error = rcar_sysc_pd_setup(pd);
415 if (error)
416 goto out_put;
417
418 domains->domains[area->isr_bit] = &pd->genpd;
419 }
420
421 /*
422 * Second, link all PM domains to their parents
423 */
424 for (i = 0; i < info->num_areas; i++) {
425 const struct rcar_sysc_area *area = &info->areas[i];
426
427 if (!area->name || area->parent < 0)
428 continue;
429
430 error = pm_genpd_add_subdomain(domains->domains[area->parent],
431 domains->domains[area->isr_bit]);
432 if (error)
433 pr_warn("Failed to add PM subdomain %s to parent %u\n",
434 area->name, area->parent);
435 }
436
437 error = of_genpd_add_provider_onecell(np, &domains->onecell_data);
438
439 out_put:
440 of_node_put(np);
441 return error;
442 }
443 early_initcall(rcar_sysc_pd_init);
444
rcar_sysc_nullify(struct rcar_sysc_area * areas,unsigned int num_areas,u8 id)445 void __init rcar_sysc_nullify(struct rcar_sysc_area *areas,
446 unsigned int num_areas, u8 id)
447 {
448 unsigned int i;
449
450 for (i = 0; i < num_areas; i++)
451 if (areas[i].isr_bit == id) {
452 areas[i].name = NULL;
453 return;
454 }
455 }
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->ch.chan_bit != idx)
474 continue;
475
476 return on ? rcar_sysc_power_up(&pd->ch)
477 : rcar_sysc_power_down(&pd->ch);
478 }
479
480 return -ENOENT;
481 }
482
rcar_sysc_power_down_cpu(unsigned int cpu)483 int rcar_sysc_power_down_cpu(unsigned int cpu)
484 {
485 return rcar_sysc_power_cpu(cpu, false);
486 }
487
rcar_sysc_power_up_cpu(unsigned int cpu)488 int rcar_sysc_power_up_cpu(unsigned int cpu)
489 {
490 return rcar_sysc_power_cpu(cpu, true);
491 }
492 #endif /* CONFIG_ARCH_R8A7779 */
493
