| // 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 (__raw_readl(rmobile_pd->base + PSTR) & mask) { |
| unsigned int retry_count; |
| __raw_writel(mask, rmobile_pd->base + SPDCR); |
| |
| for (retry_count = PSTR_RETRIES; retry_count; retry_count--) { |
| if (!(__raw_readl(rmobile_pd->base + SPDCR) & mask)) |
| break; |
| cpu_relax(); |
| } |
| } |
| |
| pr_debug("%s: Power off, 0x%08x -> PSTR = 0x%08x\n", genpd->name, mask, |
| __raw_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 (__raw_readl(rmobile_pd->base + PSTR) & mask) |
| return ret; |
| |
| __raw_writel(mask, rmobile_pd->base + SWUCR); |
| |
| for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) { |
| if (!(__raw_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, |
| __raw_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); |