1 // SPDX-License-Identifier: GPL-2.0
3 * rmobile power management support
5 * Copyright (C) 2012 Renesas Solutions Corp.
6 * Copyright (C) 2012 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
7 * Copyright (C) 2014 Glider bvba
10 * Copyright (C) 2011 Magnus Damm
12 #include <linux/clk/renesas.h>
13 #include <linux/console.h>
14 #include <linux/delay.h>
16 #include <linux/iopoll.h>
18 #include <linux/of_address.h>
20 #include <linux/pm_clock.h>
21 #include <linux/pm_domain.h>
22 #include <linux/slab.h>
25 #define SPDCR 0x08 /* SYS Power Down Control Register */
26 #define SWUCR 0x14 /* SYS Wakeup Control Register */
27 #define PSTR 0x80 /* Power Status Register */
29 #define PSTR_RETRIES 100
30 #define PSTR_DELAY_US 10
32 struct rmobile_pm_domain {
33 struct generic_pm_domain genpd;
34 struct dev_power_governor *gov;
37 unsigned int bit_shift;
41 struct rmobile_pm_domain *to_rmobile_pd(struct generic_pm_domain *d)
43 return container_of(d, struct rmobile_pm_domain, genpd);
46 static int rmobile_pd_power_down(struct generic_pm_domain *genpd)
48 struct rmobile_pm_domain *rmobile_pd = to_rmobile_pd(genpd);
49 unsigned int mask = BIT(rmobile_pd->bit_shift);
52 if (rmobile_pd->suspend) {
53 int ret = rmobile_pd->suspend();
59 if (readl(rmobile_pd->base + PSTR) & mask) {
60 writel(mask, rmobile_pd->base + SPDCR);
62 readl_poll_timeout_atomic(rmobile_pd->base + SPDCR, val,
63 !(val & mask), 0, PSTR_RETRIES);
66 pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n", genpd->name, mask,
67 readl(rmobile_pd->base + PSTR));
72 static int __rmobile_pd_power_up(struct rmobile_pm_domain *rmobile_pd)
74 unsigned int val, mask = BIT(rmobile_pd->bit_shift);
77 if (readl(rmobile_pd->base + PSTR) & mask)
80 writel(mask, rmobile_pd->base + SWUCR);
82 ret = readl_poll_timeout_atomic(rmobile_pd->base + SWUCR, val,
83 (val & mask), PSTR_DELAY_US,
84 PSTR_RETRIES * PSTR_DELAY_US);
86 pr_debug("%s: Power on, 0x%08x -> PSTR = 0x%08x\n",
87 rmobile_pd->genpd.name, mask,
88 readl(rmobile_pd->base + PSTR));
93 static int rmobile_pd_power_up(struct generic_pm_domain *genpd)
95 return __rmobile_pd_power_up(to_rmobile_pd(genpd));
98 static void rmobile_init_pm_domain(struct rmobile_pm_domain *rmobile_pd)
100 struct generic_pm_domain *genpd = &rmobile_pd->genpd;
101 struct dev_power_governor *gov = rmobile_pd->gov;
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;
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);
113 pm_genpd_init(genpd, gov ? : &simple_qos_governor, false);
116 static int rmobile_pd_suspend_console(void)
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.
122 return console_suspend_enabled ? 0 : -EBUSY;
133 #define MAX_NUM_SPECIAL_PDS 16
135 static struct special_pd {
136 struct device_node *pd;
138 } special_pds[MAX_NUM_SPECIAL_PDS] __initdata;
140 static unsigned int num_special_pds __initdata;
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, },
150 static void __init add_special_pd(struct device_node *np, enum pd_types type)
153 struct device_node *pd;
155 pd = of_parse_phandle(np, "power-domains", 0);
159 for (i = 0; i < num_special_pds; i++)
160 if (pd == special_pds[i].pd && type == special_pds[i].type) {
165 if (num_special_pds == ARRAY_SIZE(special_pds)) {
166 pr_warn("Too many special PM domains\n");
171 pr_debug("Special PM domain %pOFn type %d for %pOF\n", pd, type, np);
173 special_pds[num_special_pds].pd = pd;
174 special_pds[num_special_pds].type = type;
178 static void __init get_special_pds(void)
180 struct device_node *np;
181 const struct of_device_id *id;
183 /* PM domains containing CPUs */
184 for_each_of_cpu_node(np)
185 add_special_pd(np, PD_CPU);
187 /* PM domain containing console */
189 add_special_pd(of_stdout, PD_CONSOLE);
191 /* PM domains containing other special devices */
192 for_each_matching_node_and_match(np, special_ids, &id)
193 add_special_pd(np, (uintptr_t)id->data);
196 static void __init put_special_pds(void)
200 for (i = 0; i < num_special_pds; i++)
201 of_node_put(special_pds[i].pd);
204 static enum pd_types __init pd_type(const struct device_node *pd)
208 for (i = 0; i < num_special_pds; i++)
209 if (pd == special_pds[i].pd)
210 return special_pds[i].type;
215 static void __init rmobile_setup_pm_domain(struct device_node *np,
216 struct rmobile_pm_domain *pd)
218 const char *name = pd->genpd.name;
220 switch (pd_type(np)) {
223 * This domain contains the CPU core and therefore it should
224 * only be turned off if the CPU is not in use.
226 pr_debug("PM domain %s contains CPU\n", name);
227 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
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;
238 * This domain contains the Coresight-ETM hardware block and
239 * therefore it should only be turned off if the debug module
242 pr_debug("PM domain %s contains Coresight-ETM\n", name);
243 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
248 * This domain contains a memory-controller and therefore it
249 * should only be turned off if memory is not in use.
251 pr_debug("PM domain %s contains MEMCTL\n", name);
252 pd->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
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;
264 rmobile_init_pm_domain(pd);
267 static int __init rmobile_add_pm_domains(void __iomem *base,
268 struct device_node *parent,
269 struct generic_pm_domain *genpd_parent)
271 struct device_node *np;
273 for_each_child_of_node(parent, np) {
274 struct rmobile_pm_domain *pd;
277 if (of_property_read_u32(np, "reg", &idx)) {
278 /* always-on domain */
281 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
287 pd->genpd.name = np->name;
291 rmobile_setup_pm_domain(np, pd);
293 pm_genpd_add_subdomain(genpd_parent, &pd->genpd);
294 of_genpd_add_provider_simple(np, &pd->genpd);
296 rmobile_add_pm_domains(base, np, &pd->genpd);
301 static int __init rmobile_init_pm_domains(void)
303 struct device_node *np, *pmd;
304 bool scanned = false;
308 for_each_compatible_node(np, NULL, "renesas,sysc-rmobile") {
309 base = of_iomap(np, 0);
311 pr_warn("%pOF cannot map reg 0\n", np);
315 pmd = of_get_child_by_name(np, "pm-domains");
318 pr_warn("%pOF lacks pm-domains node\n", np);
323 /* Find PM domains containing special blocks */
328 ret = rmobile_add_pm_domains(base, pmd, NULL);
335 fwnode_dev_initialized(of_fwnode_handle(np), true);
343 core_initcall(rmobile_init_pm_domains);