summaryrefslogtreecommitdiff
path: root/drivers/soc/renesas/rmobile-sysc.c
blob: 9046b8c933cbe03110931be2a89dd894fa750716 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
// SPDX-License-Identifier: GPL-2.0
/*
 * rmobile power management support
 *
 * Copyright (C) 2012  Renesas Solutions Corp.
 * Copyright (C) 2012  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
 * Copyright (C) 2014  Glider bvba
 *
 * based on pm-sh7372.c
 *  Copyright (C) 2011 Magnus Damm
 */
#include <linux/clk/renesas.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_clock.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>

#include <asm/io.h>

/* SYSC */
#define SPDCR		0x08	/* SYS Power Down Control Register */
#define SWUCR		0x14	/* SYS Wakeup Control Register */
#define PSTR		0x80	/* Power Status Register */

#define PSTR_RETRIES	100
#define PSTR_DELAY_US	10

struct rmobile_pm_domain {
	struct generic_pm_domain genpd;
	struct dev_power_governor *gov;
	int (*suspend)(void);
	void __iomem *base;
	unsigned int bit_shift;
};

static inline
struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
{
	return container_of(d, struct rmobile_pm_domain, genpd);
}

static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
{
	struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
	unsigned int mask = BIT(rmobile_pd->bit_shift);

	if (rmobile_pd->suspend) {
		int ret = rmobile_pd->suspend();

		if (ret)
			return ret;
	}

	if (readl(rmobile_pd->base + PSTR) & mask) {
		unsigned int retry_count;
		writel(mask, rmobile_pd->base + SPDCR);

		for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
			if (!(readl(rmobile_pd->base + SPDCR) & mask))
				break;
			cpu_relax();
		}
	}

	pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n", genpd->name, mask,
		 readl(rmobile_pd->base + PSTR));

	return 0;
}

static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd)
{
	unsigned int mask = BIT(rmobile_pd->bit_shift);
	unsigned int retry_count;
	int ret = 0;

	if (readl(rmobile_pd->base + PSTR) & mask)
		return ret;

	writel(mask, rmobile_pd->base + SWUCR);

	for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
		if (!(readl(rmobile_pd->base + SWUCR) & mask))
			break;
		if (retry_count > PSTR_RETRIES)
			udelay(PSTR_DELAY_US);
		else
			cpu_relax();
	}
	if (!retry_count)
		ret = -EIO;

	pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
		 rmobile_pd->genpd.name, mask,
		 readl(rmobile_pd->base + PSTR));

	return ret;
}

static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
{
	return __rmobile_pd_power_up(to_rmobile_pd(genpd));
}

static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
{
	struct generic_pm_domain *genpd = &rmobile_pd->genpd;
	struct dev_power_governor *gov = rmobile_pd->gov;

	genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP;
	genpd->attach_dev = cpg_mstp_attach_dev;
	genpd->detach_dev = cpg_mstp_detach_dev;

	if (!(genpd->flags & GENPD_FLAG_ALWAYS_ON)) {
		genpd->power_off = rmobile_pd_power_down;
		genpd->power_on = rmobile_pd_power_up;
		__rmobile_pd_power_up(rmobile_pd);
	}

	pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
}

static int rmobile_pd_suspend_console(void)
{
	/*
	 * Serial consoles make use of SCIF hardware located in this domain,
	 * hence keep the power domain on if "no_console_suspend" is set.
	 */
	return console_suspend_enabled ? 0 : -EBUSY;
}

enum pd_types {
	PD_NORMAL,
	PD_CPU,
	PD_CONSOLE,
	PD_DEBUG,
	PD_MEMCTL,
};

#define MAX_NUM_SPECIAL_PDS	16

static struct special_pd {
	struct device_node *pd;
	enum pd_types type;
} special_pds[MAX_NUM_SPECIAL_PDS] __initdata;

static unsigned int num_special_pds __initdata;

static const struct of_device_id special_ids[] __initconst = {
	{ .compatible = "arm,coresight-etm3x", .data = (void *)PD_DEBUG },
	{ .compatible = "renesas,dbsc-r8a73a4", .data = (void *)PD_MEMCTL, },
	{ .compatible = "renesas,dbsc3-r8a7740", .data = (void *)PD_MEMCTL, },
	{ .compatible = "renesas,sbsc-sh73a0", .data = (void *)PD_MEMCTL, },
	{ /* sentinel */ },
};

static void __init add_special_pd(struct device_node *np, enum pd_types type)
{
	unsigned int i;
	struct device_node *pd;

	pd = of_parse_phandle(np, "power-domains", 0);
	if (!pd)
		return;

	for (i = 0; i < num_special_pds; i++)
		if (pd == special_pds[i].pd && type == special_pds[i].type) {
			of_node_put(pd);
			return;
		}

	if (num_special_pds == ARRAY_SIZE(special_pds)) {
		pr_warn("Too many special PM domains\n");
		of_node_put(pd);
		return;
	}

	pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);

	special_pds[num_special_pds].pd = pd;
	special_pds[num_special_pds].type = type;
	num_special_pds++;
}

static void __init get_special_pds(void)
{
	struct device_node *np;
	const struct of_device_id *id;

	/* PM domains containing CPUs */
	for_each_of_cpu_node(np)
		add_special_pd(np, PD_CPU);

	/* PM domain containing console */
	if (of_stdout)
		add_special_pd(of_stdout, PD_CONSOLE);

	/* PM domains containing other special devices */
	for_each_matching_node_and_match(np, special_ids, &id)
		add_special_pd(np, (enum pd_types)id->data);
}

static void __init put_special_pds(void)
{
	unsigned int i;

	for (i = 0; i < num_special_pds; i++)
		of_node_put(special_pds[i].pd);
}

static enum pd_types __init pd_type(const struct device_node *pd)
{
	unsigned int i;

	for (i = 0; i < num_special_pds; i++)
		if (pd == special_pds[i].pd)
			return special_pds[i].type;

	return PD_NORMAL;
}

static void __init rmobile_setup_pm_domain(struct device_node *np,
					   struct rmobile_pm_domain *pd)
{
	const char *name = pd->genpd.name;

	switch (pd_type(np)) {
	case PD_CPU:
		/*
		 * This domain contains the CPU core and therefore it should
		 * only be turned off if the CPU is not in use.
		 */
		pr_debug("PM domain %s contains CPU\n", name);
		pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
		break;

	case PD_CONSOLE:
		pr_debug("PM domain %s contains serial console\n", name);
		pd->gov = &pm_domain_always_on_gov;
		pd->suspend = rmobile_pd_suspend_console;
		break;

	case PD_DEBUG:
		/*
		 * This domain contains the Coresight-ETM hardware block and
		 * therefore it should only be turned off if the debug module
		 * is not in use.
		 */
		pr_debug("PM domain %s contains Coresight-ETM\n", name);
		pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
		break;

	case PD_MEMCTL:
		/*
		 * This domain contains a memory-controller and therefore it
		 * should only be turned off if memory is not in use.
		 */
		pr_debug("PM domain %s contains MEMCTL\n", name);
		pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
		break;

	case PD_NORMAL:
		if (pd->bit_shift == ~0) {
			/* Top-level always-on domain */
			pr_debug("PM domain %s is always-on domain\n", name);
			pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
		}
		break;
	}

	rmobile_init_pm_domain(pd);
}

static int __init rmobile_add_pm_domains(void __iomem *base,
					 struct device_node *parent,
					 struct generic_pm_domain *genpd_parent)
{
	struct device_node *np;

	for_each_child_of_node(parent, np) {
		struct rmobile_pm_domain *pd;
		u32 idx = ~0;

		if (of_property_read_u32(np, "reg", &idx)) {
			/* always-on domain */
		}

		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
		if (!pd) {
			of_node_put(np);
			return -ENOMEM;
		}

		pd->genpd.name = np->name;
		pd->base = base;
		pd->bit_shift = idx;

		rmobile_setup_pm_domain(np, pd);
		if (genpd_parent)
			pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
		of_genpd_add_provider_simple(np, &pd->genpd);

		rmobile_add_pm_domains(base, np, &pd->genpd);
	}
	return 0;
}

static int __init rmobile_init_pm_domains(void)
{
	struct device_node *np, *pmd;
	bool scanned = false;
	void __iomem *base;
	int ret = 0;

	for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
		base = of_iomap(np, 0);
		if (!base) {
			pr_warn("%pOF cannot map reg 0\n", np);
			continue;
		}

		pmd = of_get_child_by_name(np, "pm-domains");
		if (!pmd) {
			iounmap(base);
			pr_warn("%pOF lacks pm-domains node\n", np);
			continue;
		}

		if (!scanned) {
			/* Find PM domains containing special blocks */
			get_special_pds();
			scanned = true;
		}

		ret = rmobile_add_pm_domains(base, pmd, NULL);
		of_node_put(pmd);
		if (ret) {
			of_node_put(np);
			break;
		}
	}

	put_special_pds();

	return ret;
}

core_initcall(rmobile_init_pm_domains);