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