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
 34struct 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
 42static inline
 43struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
 44{
 45	return container_of(d, struct rmobile_pm_domain, genpd);
 46}
 47
 48static 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
 77static 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
106static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
107{
108	return __rmobile_pd_power_up(to_rmobile_pd(genpd));
109}
110
111static 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
129static 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
138enum 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
148static struct special_pd {
149	struct device_node *pd;
150	enum pd_types type;
151} special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
152
153static unsigned int num_special_pds __initdata;
154
155static 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
163static 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
191static 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
209static 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
217static 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
228static 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
280static 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
314static 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
353core_initcall(rmobile_init_pm_domains);