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->attach_dev = cpg_mstp_attach_dev;
105 genpd->detach_dev = cpg_mstp_detach_dev;
106
107 if (!(genpd->flags & GENPD_FLAG_ALWAYS_ON)) {
108 genpd->power_off = rmobile_pd_power_down;
109 genpd->power_on = rmobile_pd_power_up;
110 __rmobile_pd_power_up(rmobile_pd);
111 }
112
113 pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
114 }
115
rmobile_pd_suspend_console(void)116 static int rmobile_pd_suspend_console(void)
117 {
118 /*
119 * Serial consoles make use of SCIF hardware located in this domain,
120 * hence keep the power domain on if "no_console_suspend" is set.
121 */
122 return console_suspend_enabled ? 0 : -EBUSY;
123 }
124
125 enum pd_types {
126 PD_NORMAL,
127 PD_CPU,
128 PD_CONSOLE,
129 PD_DEBUG,
130 PD_MEMCTL,
131 };
132
133 #define MAX_NUM_SPECIAL_PDS 16
134
135 static struct special_pd {
136 struct device_node *pd;
137 enum pd_types type;
138 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
139
140 static unsigned int num_special_pds __initdata;
141
142 static const struct of_device_id special_ids[] __initconst = {
143 { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
144 { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
145 { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
146 { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
147 { /* sentinel */ },
148 };
149
add_special_pd(struct device_node * np,enum pd_types type)150 static void __init add_special_pd(struct device_node *np, enum pd_types type)
151 {
152 unsigned int i;
153 struct device_node *pd;
154
155 pd = of_parse_phandle(np, "power-domains", 0);
156 if (!pd)
157 return;
158
159 for (i = 0; i < num_special_pds; i++)
160 if (pd == special_pds[i].pd && type == special_pds[i].type) {
161 of_node_put(pd);
162 return;
163 }
164
165 if (num_special_pds == ARRAY_SIZE(special_pds)) {
166 pr_warn("Too many special PM domains\n");
167 of_node_put(pd);
168 return;
169 }
170
171 pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);
172
173 special_pds[num_special_pds].pd = pd;
174 special_pds[num_special_pds].type = type;
175 num_special_pds++;
176 }
177
get_special_pds(void)178 static void __init get_special_pds(void)
179 {
180 struct device_node *np;
181 const struct of_device_id *id;
182
183 /* PM domains containing CPUs */
184 for_each_of_cpu_node(np)
185 add_special_pd(np, PD_CPU);
186
187 /* PM domain containing console */
188 if (of_stdout)
189 add_special_pd(of_stdout, PD_CONSOLE);
190
191 /* PM domains containing other special devices */
192 for_each_matching_node_and_match(np, special_ids, &id)
193 add_special_pd(np, (enum pd_types)id->data);
194 }
195
put_special_pds(void)196 static void __init put_special_pds(void)
197 {
198 unsigned int i;
199
200 for (i = 0; i < num_special_pds; i++)
201 of_node_put(special_pds[i].pd);
202 }
203
pd_type(const struct device_node * pd)204 static enum pd_types __init pd_type(const struct device_node *pd)
205 {
206 unsigned int i;
207
208 for (i = 0; i < num_special_pds; i++)
209 if (pd == special_pds[i].pd)
210 return special_pds[i].type;
211
212 return PD_NORMAL;
213 }
214
rmobile_setup_pm_domain(struct device_node * np,struct rmobile_pm_domain * pd)215 static void __init rmobile_setup_pm_domain(struct device_node *np,
216 struct rmobile_pm_domain *pd)
217 {
218 const char *name = pd->genpd.name;
219
220 switch (pd_type(np)) {
221 case PD_CPU:
222 /*
223 * This domain contains the CPU core and therefore it should
224 * only be turned off if the CPU is not in use.
225 */
226 pr_debug("PM domain %s contains CPU\n", name);
227 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
228 break;
229
230 case PD_CONSOLE:
231 pr_debug("PM domain %s contains serial console\n", name);
232 pd->gov = &pm_domain_always_on_gov;
233 pd->suspend = rmobile_pd_suspend_console;
234 break;
235
236 case PD_DEBUG:
237 /*
238 * This domain contains the Coresight-ETM hardware block and
239 * therefore it should only be turned off if the debug module
240 * is not in use.
241 */
242 pr_debug("PM domain %s contains Coresight-ETM\n", name);
243 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
244 break;
245
246 case PD_MEMCTL:
247 /*
248 * This domain contains a memory-controller and therefore it
249 * should only be turned off if memory is not in use.
250 */
251 pr_debug("PM domain %s contains MEMCTL\n", name);
252 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
253 break;
254
255 case PD_NORMAL:
256 if (pd->bit_shift == ~0) {
257 /* Top-level always-on domain */
258 pr_debug("PM domain %s is always-on domain\n", name);
259 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
260 }
261 break;
262 }
263
264 rmobile_init_pm_domain(pd);
265 }
266
rmobile_add_pm_domains(void __iomem * base,struct device_node * parent,struct generic_pm_domain * genpd_parent)267 static int __init rmobile_add_pm_domains(void __iomem *base,
268 struct device_node *parent,
269 struct generic_pm_domain *genpd_parent)
270 {
271 struct device_node *np;
272
273 for_each_child_of_node(parent, np) {
274 struct rmobile_pm_domain *pd;
275 u32 idx = ~0;
276
277 if (of_property_read_u32(np, "reg", &idx)) {
278 /* always-on domain */
279 }
280
281 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
282 if (!pd) {
283 of_node_put(np);
284 return -ENOMEM;
285 }
286
287 pd->genpd.name = np->name;
288 pd->base = base;
289 pd->bit_shift = idx;
290
291 rmobile_setup_pm_domain(np, pd);
292 if (genpd_parent)
293 pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
294 of_genpd_add_provider_simple(np, &pd->genpd);
295
296 rmobile_add_pm_domains(base, np, &pd->genpd);
297 }
298 return 0;
299 }
300
rmobile_init_pm_domains(void)301 static int __init rmobile_init_pm_domains(void)
302 {
303 struct device_node *np, *pmd;
304 bool scanned = false;
305 void __iomem *base;
306 int ret = 0;
307
308 for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
309 base = of_iomap(np, 0);
310 if (!base) {
311 pr_warn("%pOF cannot map reg 0\n", np);
312 continue;
313 }
314
315 pmd = of_get_child_by_name(np, "pm-domains");
316 if (!pmd) {
317 iounmap(base);
318 pr_warn("%pOF lacks pm-domains node\n", np);
319 continue;
320 }
321
322 if (!scanned) {
323 /* Find PM domains containing special blocks */
324 get_special_pds();
325 scanned = true;
326 }
327
328 ret = rmobile_add_pm_domains(base, pmd, NULL);
329 of_node_put(pmd);
330 if (ret) {
331 of_node_put(np);
332 break;
333 }
334
335 fwnode_dev_initialized(of_fwnode_handle(np), true);
336 }
337
338 put_special_pds();
339
340 return ret;
341 }
342
343 core_initcall(rmobile_init_pm_domains);
344