diff options
Diffstat (limited to 'drivers/soc/renesas/rmobile-sysc.c')
| -rw-r--r-- | drivers/soc/renesas/rmobile-sysc.c | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/drivers/soc/renesas/rmobile-sysc.c b/drivers/soc/renesas/rmobile-sysc.c new file mode 100644 index 000000000..beb1c7211 --- /dev/null +++ b/drivers/soc/renesas/rmobile-sysc.c @@ -0,0 +1,354 @@ +// 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 (__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); 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