1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * rmobile power management support
4 *
5 * Copyright (C) 2012 Renesas Solutions Corp.
6 * Copyright (C) 2012 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
7 * Copyright (C) 2014 Glider bvba
8 *
9 * based on pm-sh7372.c
10 * Copyright (C) 2011 Magnus Damm
11 */
12 #include <linux/clk/renesas.h>
13 #include <linux/console.h>
14 #include <linux/delay.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/pm.h>
18 #include <linux/pm_clock.h>
19 #include <linux/pm_domain.h>
20 #include <linux/slab.h>
21
22 #include <asm/io.h>
23
24 /* SYSC */
25 #define SPDCR 0x08 /* SYS Power Down Control Register */
26 #define SWUCR 0x14 /* SYS Wakeup Control Register */
27 #define PSTR 0x80 /* Power Status Register */
28
29 #define PSTR_RETRIES 100
30 #define PSTR_DELAY_US 10
31
32 struct rmobile_pm_domain {
33 struct generic_pm_domain genpd;
34 struct dev_power_governor *gov;
35 int (*suspend)(void);
36 void __iomem *base;
37 unsigned int bit_shift;
38 };
39
40 static inline
to_rmobile_pd(struct generic_pm_domain * d)41 struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
42 {
43 return container_of(d, struct rmobile_pm_domain, genpd);
44 }
45
rmobile_pd_power_down(struct generic_pm_domain * genpd)46 static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
47 {
48 struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
49 unsigned int mask = BIT(rmobile_pd->bit_shift);
50
51 if (rmobile_pd->suspend) {
52 int ret = rmobile_pd->suspend();
53
54 if (ret)
55 return ret;
56 }
57
58 if (readl(rmobile_pd->base + PSTR) & mask) {
59 unsigned int retry_count;
60 writel(mask, rmobile_pd->base + SPDCR);
61
62 for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
63 if (!(readl(rmobile_pd->base + SPDCR) & mask))
64 break;
65 cpu_relax();
66 }
67 }
68
69 pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n", genpd->name, mask,
70 readl(rmobile_pd->base + PSTR));
71
72 return 0;
73 }
74
__rmobile_pd_power_up(struct rmobile_pm_domain * rmobile_pd)75 static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd)
76 {
77 unsigned int mask = BIT(rmobile_pd->bit_shift);
78 unsigned int retry_count;
79 int ret = 0;
80
81 if (readl(rmobile_pd->base + PSTR) & mask)
82 return ret;
83
84 writel(mask, rmobile_pd->base + SWUCR);
85
86 for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
87 if (!(readl(rmobile_pd->base + SWUCR) & mask))
88 break;
89 if (retry_count > PSTR_RETRIES)
90 udelay(PSTR_DELAY_US);
91 else
92 cpu_relax();
93 }
94 if (!retry_count)
95 ret = -EIO;
96
97 pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
98 rmobile_pd->genpd.name, mask,
99 readl(rmobile_pd->base + PSTR));
100
101 return ret;
102 }
103
rmobile_pd_power_up(struct generic_pm_domain * genpd)104 static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
105 {
106 return __rmobile_pd_power_up(to_rmobile_pd(genpd));
107 }
108
rmobile_init_pm_domain(struct rmobile_pm_domain * rmobile_pd)109 static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
110 {
111 struct generic_pm_domain *genpd = &rmobile_pd->genpd;
112 struct dev_power_governor *gov = rmobile_pd->gov;
113
114 genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
115 genpd->attach_dev = cpg_mstp_attach_dev;
116 genpd->detach_dev = cpg_mstp_detach_dev;
117
118 if (!(genpd->flags & GENPD_FLAG_ALWAYS_ON)) {
119 genpd->power_off = rmobile_pd_power_down;
120 genpd->power_on = rmobile_pd_power_up;
121 __rmobile_pd_power_up(rmobile_pd);
122 }
123
124 pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
125 }
126
rmobile_pd_suspend_console(void)127 static int rmobile_pd_suspend_console(void)
128 {
129 /*
130 * Serial consoles make use of SCIF hardware located in this domain,
131 * hence keep the power domain on if "no_console_suspend" is set.
132 */
133 return console_suspend_enabled ? 0 : -EBUSY;
134 }
135
136 enum pd_types {
137 PD_NORMAL,
138 PD_CPU,
139 PD_CONSOLE,
140 PD_DEBUG,
141 PD_MEMCTL,
142 };
143
144 #define MAX_NUM_SPECIAL_PDS 16
145
146 static struct special_pd {
147 struct device_node *pd;
148 enum pd_types type;
149 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
150
151 static unsigned int num_special_pds __initdata;
152
153 static const struct of_device_id special_ids[] __initconst = {
154 { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
155 { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
156 { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
157 { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
158 { /* sentinel */ },
159 };
160
add_special_pd(struct device_node * np,enum pd_types type)161 static void __init add_special_pd(struct device_node *np, enum pd_types type)
162 {
163 unsigned int i;
164 struct device_node *pd;
165
166 pd = of_parse_phandle(np, "power-domains", 0);
167 if (!pd)
168 return;
169
170 for (i = 0; i < num_special_pds; i++)
171 if (pd == special_pds[i].pd && type == special_pds[i].type) {
172 of_node_put(pd);
173 return;
174 }
175
176 if (num_special_pds == ARRAY_SIZE(special_pds)) {
177 pr_warn("Too many special PM domains\n");
178 of_node_put(pd);
179 return;
180 }
181
182 pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);
183
184 special_pds[num_special_pds].pd = pd;
185 special_pds[num_special_pds].type = type;
186 num_special_pds++;
187 }
188
get_special_pds(void)189 static void __init get_special_pds(void)
190 {
191 struct device_node *np;
192 const struct of_device_id *id;
193
194 /* PM domains containing CPUs */
195 for_each_of_cpu_node(np)
196 add_special_pd(np, PD_CPU);
197
198 /* PM domain containing console */
199 if (of_stdout)
200 add_special_pd(of_stdout, PD_CONSOLE);
201
202 /* PM domains containing other special devices */
203 for_each_matching_node_and_match(np, special_ids, &id)
204 add_special_pd(np, (enum pd_types)id->data);
205 }
206
put_special_pds(void)207 static void __init put_special_pds(void)
208 {
209 unsigned int i;
210
211 for (i = 0; i < num_special_pds; i++)
212 of_node_put(special_pds[i].pd);
213 }
214
pd_type(const struct device_node * pd)215 static enum pd_types __init pd_type(const struct device_node *pd)
216 {
217 unsigned int i;
218
219 for (i = 0; i < num_special_pds; i++)
220 if (pd == special_pds[i].pd)
221 return special_pds[i].type;
222
223 return PD_NORMAL;
224 }
225
rmobile_setup_pm_domain(struct device_node * np,struct rmobile_pm_domain * pd)226 static void __init rmobile_setup_pm_domain(struct device_node *np,
227 struct rmobile_pm_domain *pd)
228 {
229 const char *name = pd->genpd.name;
230
231 switch (pd_type(np)) {
232 case PD_CPU:
233 /*
234 * This domain contains the CPU core and therefore it should
235 * only be turned off if the CPU is not in use.
236 */
237 pr_debug("PM domain %s contains CPU\n", name);
238 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
239 break;
240
241 case PD_CONSOLE:
242 pr_debug("PM domain %s contains serial console\n", name);
243 pd->gov = &pm_domain_always_on_gov;
244 pd->suspend = rmobile_pd_suspend_console;
245 break;
246
247 case PD_DEBUG:
248 /*
249 * This domain contains the Coresight-ETM hardware block and
250 * therefore it should only be turned off if the debug module
251 * is not in use.
252 */
253 pr_debug("PM domain %s contains Coresight-ETM\n", name);
254 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
255 break;
256
257 case PD_MEMCTL:
258 /*
259 * This domain contains a memory-controller and therefore it
260 * should only be turned off if memory is not in use.
261 */
262 pr_debug("PM domain %s contains MEMCTL\n", name);
263 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
264 break;
265
266 case PD_NORMAL:
267 if (pd->bit_shift == ~0) {
268 /* Top-level always-on domain */
269 pr_debug("PM domain %s is always-on domain\n", name);
270 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
271 }
272 break;
273 }
274
275 rmobile_init_pm_domain(pd);
276 }
277
rmobile_add_pm_domains(void __iomem * base,struct device_node * parent,struct generic_pm_domain * genpd_parent)278 static int __init rmobile_add_pm_domains(void __iomem *base,
279 struct device_node *parent,
280 struct generic_pm_domain *genpd_parent)
281 {
282 struct device_node *np;
283
284 for_each_child_of_node(parent, np) {
285 struct rmobile_pm_domain *pd;
286 u32 idx = ~0;
287
288 if (of_property_read_u32(np, "reg", &idx)) {
289 /* always-on domain */
290 }
291
292 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
293 if (!pd) {
294 of_node_put(np);
295 return -ENOMEM;
296 }
297
298 pd->genpd.name = np->name;
299 pd->base = base;
300 pd->bit_shift = idx;
301
302 rmobile_setup_pm_domain(np, pd);
303 if (genpd_parent)
304 pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
305 of_genpd_add_provider_simple(np, &pd->genpd);
306
307 rmobile_add_pm_domains(base, np, &pd->genpd);
308 }
309 return 0;
310 }
311
rmobile_init_pm_domains(void)312 static int __init rmobile_init_pm_domains(void)
313 {
314 struct device_node *np, *pmd;
315 bool scanned = false;
316 void __iomem *base;
317 int ret = 0;
318
319 for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
320 base = of_iomap(np, 0);
321 if (!base) {
322 pr_warn("%pOF cannot map reg 0\n", np);
323 continue;
324 }
325
326 pmd = of_get_child_by_name(np, "pm-domains");
327 if (!pmd) {
328 iounmap(base);
329 pr_warn("%pOF lacks pm-domains node\n", np);
330 continue;
331 }
332
333 if (!scanned) {
334 /* Find PM domains containing special blocks */
335 get_special_pds();
336 scanned = true;
337 }
338
339 ret = rmobile_add_pm_domains(base, pmd, NULL);
340 of_node_put(pmd);
341 if (ret) {
342 of_node_put(np);
343 break;
344 }
345
346 fwnode_dev_initialized(&np->fwnode, true);
347 }
348
349 put_special_pds();
350
351 return ret;
352 }
353
354 core_initcall(rmobile_init_pm_domains);
355