1 /*
2 * rmobile power management support
3 *
4 * Copyright (C) 2012 Renesas Solutions Corp.
5 * Copyright (C) 2012 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
6 * Copyright (C) 2014 Glider bvba
7 *
8 * based on pm-sh7372.c
9 * Copyright (C) 2011 Magnus Damm
10 *
11 * This file is subject to the terms and conditions of the GNU General Public
12 * License. See the file "COPYING" in the main directory of this archive
13 * for more details.
14 */
15 #include <linux/clk/shmobile.h>
16 #include <linux/console.h>
17 #include <linux/delay.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm.h>
23 #include <linux/pm_clock.h>
24 #include <linux/slab.h>
25
26 #include <asm/io.h>
27
28 #include "pm-rmobile.h"
29
30 /* SYSC */
31 #define SPDCR 0x08 /* SYS Power Down Control Register */
32 #define SWUCR 0x14 /* SYS Wakeup Control Register */
33 #define PSTR 0x80 /* Power Status Register */
34
35 #define PSTR_RETRIES 100
36 #define PSTR_DELAY_US 10
37
38 static inline
to_rmobile_pd(struct generic_pm_domain * d)39 struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
40 {
41 return container_of(d, struct rmobile_pm_domain, genpd);
42 }
43
rmobile_pd_power_down(struct generic_pm_domain * genpd)44 static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
45 {
46 struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
47 unsigned int mask;
48
49 if (rmobile_pd->bit_shift == ~0)
50 return -EBUSY;
51
52 mask = BIT(rmobile_pd->bit_shift);
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 if (!rmobile_pd->no_debug)
72 pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n",
73 genpd->name, mask,
74 __raw_readl(rmobile_pd->base + PSTR));
75
76 return 0;
77 }
78
__rmobile_pd_power_up(struct rmobile_pm_domain * rmobile_pd,bool do_resume)79 static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd,
80 bool do_resume)
81 {
82 unsigned int mask;
83 unsigned int retry_count;
84 int ret = 0;
85
86 if (rmobile_pd->bit_shift == ~0)
87 return 0;
88
89 mask = BIT(rmobile_pd->bit_shift);
90 if (__raw_readl(rmobile_pd->base + PSTR) & mask)
91 goto out;
92
93 __raw_writel(mask, rmobile_pd->base + SWUCR);
94
95 for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
96 if (!(__raw_readl(rmobile_pd->base + SWUCR) & mask))
97 break;
98 if (retry_count > PSTR_RETRIES)
99 udelay(PSTR_DELAY_US);
100 else
101 cpu_relax();
102 }
103 if (!retry_count)
104 ret = -EIO;
105
106 if (!rmobile_pd->no_debug)
107 pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
108 rmobile_pd->genpd.name, mask,
109 __raw_readl(rmobile_pd->base + PSTR));
110
111 out:
112 if (ret == 0 && rmobile_pd->resume && do_resume)
113 rmobile_pd->resume();
114
115 return ret;
116 }
117
rmobile_pd_power_up(struct generic_pm_domain * genpd)118 static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
119 {
120 return __rmobile_pd_power_up(to_rmobile_pd(genpd), true);
121 }
122
rmobile_pd_active_wakeup(struct device * dev)123 static bool rmobile_pd_active_wakeup(struct device *dev)
124 {
125 return true;
126 }
127
rmobile_init_pm_domain(struct rmobile_pm_domain * rmobile_pd)128 static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
129 {
130 struct generic_pm_domain *genpd = &rmobile_pd->genpd;
131 struct dev_power_governor *gov = rmobile_pd->gov;
132
133 genpd->flags = GENPD_FLAG_PM_CLK;
134 pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
135 genpd->dev_ops.active_wakeup = rmobile_pd_active_wakeup;
136 genpd->power_off = rmobile_pd_power_down;
137 genpd->power_on = rmobile_pd_power_up;
138 genpd->attach_dev = cpg_mstp_attach_dev;
139 genpd->detach_dev = cpg_mstp_detach_dev;
140 __rmobile_pd_power_up(rmobile_pd, false);
141 }
142
rmobile_pd_suspend_busy(void)143 static int rmobile_pd_suspend_busy(void)
144 {
145 /*
146 * This domain should not be turned off.
147 */
148 return -EBUSY;
149 }
150
rmobile_pd_suspend_console(void)151 static int rmobile_pd_suspend_console(void)
152 {
153 /*
154 * Serial consoles make use of SCIF hardware located in this domain,
155 * hence keep the power domain on if "no_console_suspend" is set.
156 */
157 return console_suspend_enabled ? 0 : -EBUSY;
158 }
159
160 enum pd_types {
161 PD_NORMAL,
162 PD_CPU,
163 PD_CONSOLE,
164 PD_DEBUG,
165 PD_MEMCTL,
166 };
167
168 #define MAX_NUM_SPECIAL_PDS 16
169
170 static struct special_pd {
171 struct device_node *pd;
172 enum pd_types type;
173 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
174
175 static unsigned int num_special_pds __initdata;
176
177 static const struct of_device_id special_ids[] __initconst = {
178 { .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
179 { .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
180 { .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
181 { .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
182 { /* sentinel */ },
183 };
184
add_special_pd(struct device_node * np,enum pd_types type)185 static void __init add_special_pd(struct device_node *np, enum pd_types type)
186 {
187 unsigned int i;
188 struct device_node *pd;
189
190 pd = of_parse_phandle(np, "power-domains", 0);
191 if (!pd)
192 return;
193
194 for (i = 0; i < num_special_pds; i++)
195 if (pd == special_pds[i].pd && type == special_pds[i].type) {
196 of_node_put(pd);
197 return;
198 }
199
200 if (num_special_pds == ARRAY_SIZE(special_pds)) {
201 pr_warn("Too many special PM domains\n");
202 of_node_put(pd);
203 return;
204 }
205
206 pr_debug("Special PM domain %s type %d for %s\n", pd->name, type,
207 np->full_name);
208
209 special_pds[num_special_pds].pd = pd;
210 special_pds[num_special_pds].type = type;
211 num_special_pds++;
212 }
213
get_special_pds(void)214 static void __init get_special_pds(void)
215 {
216 struct device_node *np;
217 const struct of_device_id *id;
218
219 /* PM domains containing CPUs */
220 for_each_node_by_type(np, "cpu")
221 add_special_pd(np, PD_CPU);
222
223 /* PM domain containing console */
224 if (of_stdout)
225 add_special_pd(of_stdout, PD_CONSOLE);
226
227 /* PM domains containing other special devices */
228 for_each_matching_node_and_match(np, special_ids, &id)
229 add_special_pd(np, (enum pd_types)id->data);
230 }
231
put_special_pds(void)232 static void __init put_special_pds(void)
233 {
234 unsigned int i;
235
236 for (i = 0; i < num_special_pds; i++)
237 of_node_put(special_pds[i].pd);
238 }
239
pd_type(const struct device_node * pd)240 static enum pd_types __init pd_type(const struct device_node *pd)
241 {
242 unsigned int i;
243
244 for (i = 0; i < num_special_pds; i++)
245 if (pd == special_pds[i].pd)
246 return special_pds[i].type;
247
248 return PD_NORMAL;
249 }
250
rmobile_setup_pm_domain(struct device_node * np,struct rmobile_pm_domain * pd)251 static void __init rmobile_setup_pm_domain(struct device_node *np,
252 struct rmobile_pm_domain *pd)
253 {
254 const char *name = pd->genpd.name;
255
256 switch (pd_type(np)) {
257 case PD_CPU:
258 /*
259 * This domain contains the CPU core and therefore it should
260 * only be turned off if the CPU is not in use.
261 */
262 pr_debug("PM domain %s contains CPU\n", name);
263 pd->gov = &pm_domain_always_on_gov;
264 pd->suspend = rmobile_pd_suspend_busy;
265 break;
266
267 case PD_CONSOLE:
268 pr_debug("PM domain %s contains serial console\n", name);
269 pd->gov = &pm_domain_always_on_gov;
270 pd->suspend = rmobile_pd_suspend_console;
271 break;
272
273 case PD_DEBUG:
274 /*
275 * This domain contains the Coresight-ETM hardware block and
276 * therefore it should only be turned off if the debug module
277 * is not in use.
278 */
279 pr_debug("PM domain %s contains Coresight-ETM\n", name);
280 pd->gov = &pm_domain_always_on_gov;
281 pd->suspend = rmobile_pd_suspend_busy;
282 break;
283
284 case PD_MEMCTL:
285 /*
286 * This domain contains a memory-controller and therefore it
287 * should only be turned off if memory is not in use.
288 */
289 pr_debug("PM domain %s contains MEMCTL\n", name);
290 pd->gov = &pm_domain_always_on_gov;
291 pd->suspend = rmobile_pd_suspend_busy;
292 break;
293
294 case PD_NORMAL:
295 break;
296 }
297
298 rmobile_init_pm_domain(pd);
299 }
300
rmobile_add_pm_domains(void __iomem * base,struct device_node * parent,struct generic_pm_domain * genpd_parent)301 static int __init rmobile_add_pm_domains(void __iomem *base,
302 struct device_node *parent,
303 struct generic_pm_domain *genpd_parent)
304 {
305 struct device_node *np;
306
307 for_each_child_of_node(parent, np) {
308 struct rmobile_pm_domain *pd;
309 u32 idx = ~0;
310
311 if (of_property_read_u32(np, "reg", &idx)) {
312 /* always-on domain */
313 }
314
315 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
316 if (!pd) {
317 of_node_put(np);
318 return -ENOMEM;
319 }
320
321 pd->genpd.name = np->name;
322 pd->base = base;
323 pd->bit_shift = idx;
324
325 rmobile_setup_pm_domain(np, pd);
326 if (genpd_parent)
327 pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
328 of_genpd_add_provider_simple(np, &pd->genpd);
329
330 rmobile_add_pm_domains(base, np, &pd->genpd);
331 }
332 return 0;
333 }
334
rmobile_init_pm_domains(void)335 static int __init rmobile_init_pm_domains(void)
336 {
337 struct device_node *np, *pmd;
338 bool scanned = false;
339 void __iomem *base;
340 int ret = 0;
341
342 for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
343 base = of_iomap(np, 0);
344 if (!base) {
345 pr_warn("%s cannot map reg 0\n", np->full_name);
346 continue;
347 }
348
349 pmd = of_get_child_by_name(np, "pm-domains");
350 if (!pmd) {
351 pr_warn("%s lacks pm-domains node\n", np->full_name);
352 continue;
353 }
354
355 if (!scanned) {
356 /* Find PM domains containing special blocks */
357 get_special_pds();
358 scanned = true;
359 }
360
361 ret = rmobile_add_pm_domains(base, pmd, NULL);
362 of_node_put(pmd);
363 if (ret) {
364 of_node_put(np);
365 break;
366 }
367 }
368
369 put_special_pds();
370
371 return ret;
372 }
373
374 core_initcall(rmobile_init_pm_domains);
375