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