diff options
Diffstat (limited to 'drivers/soc/renesas/rcar-sysc.c')
| -rw-r--r-- | drivers/soc/renesas/rcar-sysc.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c new file mode 100644 index 000000000..9b235fc90 --- /dev/null +++ b/drivers/soc/renesas/rcar-sysc.c @@ -0,0 +1,495 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * R-Car SYSC Power management support + * + * Copyright (C) 2014 Magnus Damm + * Copyright (C) 2015-2017 Glider bvba + */ + +#include <linux/clk/renesas.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/mm.h> +#include <linux/of_address.h> +#include <linux/pm_domain.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/io.h> +#include <linux/soc/renesas/rcar-sysc.h> + +#include "rcar-sysc.h" + +/* SYSC Common */ +#define SYSCSR 0x00 /* SYSC Status Register */ +#define SYSCISR 0x04 /* Interrupt Status Register */ +#define SYSCISCR 0x08 /* Interrupt Status Clear Register */ +#define SYSCIER 0x0c /* Interrupt Enable Register */ +#define SYSCIMR 0x10 /* Interrupt Mask Register */ + +/* SYSC Status Register */ +#define SYSCSR_PONENB 1 /* Ready for power resume requests */ +#define SYSCSR_POFFENB 0 /* Ready for power shutoff requests */ + +/* + * Power Control Register Offsets inside the register block for each domain + * Note: The "CR" registers for ARM cores exist on H1 only + * Use WFI to power off, CPG/APMU to resume ARM cores on R-Car Gen2 + * Use PSCI on R-Car Gen3 + */ +#define PWRSR_OFFS 0x00 /* Power Status Register */ +#define PWROFFCR_OFFS 0x04 /* Power Shutoff Control Register */ +#define PWROFFSR_OFFS 0x08 /* Power Shutoff Status Register */ +#define PWRONCR_OFFS 0x0c /* Power Resume Control Register */ +#define PWRONSR_OFFS 0x10 /* Power Resume Status Register */ +#define PWRER_OFFS 0x14 /* Power Shutoff/Resume Error */ + + +#define SYSCSR_RETRIES 100 +#define SYSCSR_DELAY_US 1 + +#define PWRER_RETRIES 100 +#define PWRER_DELAY_US 1 + +#define SYSCISR_RETRIES 1000 +#define SYSCISR_DELAY_US 1 + +#define RCAR_PD_ALWAYS_ON 32 /* Always-on power area */ + +struct rcar_sysc_ch { + u16 chan_offs; + u8 chan_bit; + u8 isr_bit; +}; + +static void __iomem *rcar_sysc_base; +static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */ +static u32 rcar_sysc_extmask_offs, rcar_sysc_extmask_val; + +static int rcar_sysc_pwr_on_off(const struct rcar_sysc_ch *sysc_ch, bool on) +{ + unsigned int sr_bit, reg_offs; + int k; + + if (on) { + sr_bit = SYSCSR_PONENB; + reg_offs = PWRONCR_OFFS; + } else { + sr_bit = SYSCSR_POFFENB; + reg_offs = PWROFFCR_OFFS; + } + + /* Wait until SYSC is ready to accept a power request */ + for (k = 0; k < SYSCSR_RETRIES; k++) { + if (ioread32(rcar_sysc_base + SYSCSR) & BIT(sr_bit)) + break; + udelay(SYSCSR_DELAY_US); + } + + if (k == SYSCSR_RETRIES) + return -EAGAIN; + + /* Submit power shutoff or power resume request */ + iowrite32(BIT(sysc_ch->chan_bit), + rcar_sysc_base + sysc_ch->chan_offs + reg_offs); + + return 0; +} + +static int rcar_sysc_power(const struct rcar_sysc_ch *sysc_ch, bool on) +{ + unsigned int isr_mask = BIT(sysc_ch->isr_bit); + unsigned int chan_mask = BIT(sysc_ch->chan_bit); + unsigned int status; + unsigned long flags; + int ret = 0; + int k; + + spin_lock_irqsave(&rcar_sysc_lock, flags); + + /* + * Mask external power requests for CPU or 3DG domains + */ + if (rcar_sysc_extmask_val) { + iowrite32(rcar_sysc_extmask_val, + rcar_sysc_base + rcar_sysc_extmask_offs); + } + + /* + * The interrupt source needs to be enabled, but masked, to prevent the + * CPU from receiving it. + */ + iowrite32(ioread32(rcar_sysc_base + SYSCIMR) | isr_mask, + rcar_sysc_base + SYSCIMR); + iowrite32(ioread32(rcar_sysc_base + SYSCIER) | isr_mask, + rcar_sysc_base + SYSCIER); + + iowrite32(isr_mask, rcar_sysc_base + SYSCISCR); + + /* Submit power shutoff or resume request until it was accepted */ + for (k = 0; k < PWRER_RETRIES; k++) { + ret = rcar_sysc_pwr_on_off(sysc_ch, on); + if (ret) + goto out; + + status = ioread32(rcar_sysc_base + + sysc_ch->chan_offs + PWRER_OFFS); + if (!(status & chan_mask)) + break; + + udelay(PWRER_DELAY_US); + } + + if (k == PWRER_RETRIES) { + ret = -EIO; + goto out; + } + + /* Wait until the power shutoff or resume request has completed * */ + for (k = 0; k < SYSCISR_RETRIES; k++) { + if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask) + break; + udelay(SYSCISR_DELAY_US); + } + + if (k == SYSCISR_RETRIES) + ret = -EIO; + + iowrite32(isr_mask, rcar_sysc_base + SYSCISCR); + + out: + if (rcar_sysc_extmask_val) + iowrite32(0, rcar_sysc_base + rcar_sysc_extmask_offs); + + spin_unlock_irqrestore(&rcar_sysc_lock, flags); + + pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off", + sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret); + return ret; +} + +static bool rcar_sysc_power_is_off(const struct rcar_sysc_ch *sysc_ch) +{ + unsigned int st; + + st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS); + if (st & BIT(sysc_ch->chan_bit)) + return true; + + return false; +} + +struct rcar_sysc_pd { + struct generic_pm_domain genpd; + struct rcar_sysc_ch ch; + unsigned int flags; + char name[]; +}; + +static inline struct rcar_sysc_pd *to_rcar_pd(struct generic_pm_domain *d) +{ + return container_of(d, struct rcar_sysc_pd, genpd); +} + +static int rcar_sysc_pd_power_off(struct generic_pm_domain *genpd) +{ + struct rcar_sysc_pd *pd = to_rcar_pd(genpd); + + pr_debug("%s: %s\n", __func__, genpd->name); + return rcar_sysc_power(&pd->ch, false); +} + +static int rcar_sysc_pd_power_on(struct generic_pm_domain *genpd) +{ + struct rcar_sysc_pd *pd = to_rcar_pd(genpd); + + pr_debug("%s: %s\n", __func__, genpd->name); + return rcar_sysc_power(&pd->ch, true); +} + +static bool has_cpg_mstp; + +static int __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd) +{ + struct generic_pm_domain *genpd = &pd->genpd; + const char *name = pd->genpd.name; + int error; + + if (pd->flags & PD_CPU) { + /* + * This domain contains a CPU core and therefore it should + * only be turned off if the CPU is not in use. + */ + pr_debug("PM domain %s contains %s\n", name, "CPU"); + genpd->flags |= GENPD_FLAG_ALWAYS_ON; + } else if (pd->flags & PD_SCU) { + /* + * This domain contains an SCU and cache-controller, and + * therefore it should only be turned off if the CPU cores are + * not in use. + */ + pr_debug("PM domain %s contains %s\n", name, "SCU"); + genpd->flags |= GENPD_FLAG_ALWAYS_ON; + } else if (pd->flags & PD_NO_CR) { + /* + * This domain cannot be turned off. + */ + genpd->flags |= GENPD_FLAG_ALWAYS_ON; + } + + if (!(pd->flags & (PD_CPU | PD_SCU))) { + /* Enable Clock Domain for I/O devices */ + genpd->flags |= GENPD_FLAG_PM_CLK | GENPD_FLAG_ACTIVE_WAKEUP; + if (has_cpg_mstp) { + genpd->attach_dev = cpg_mstp_attach_dev; + genpd->detach_dev = cpg_mstp_detach_dev; + } else { + genpd->attach_dev = cpg_mssr_attach_dev; + genpd->detach_dev = cpg_mssr_detach_dev; + } + } + + genpd->power_off = rcar_sysc_pd_power_off; + genpd->power_on = rcar_sysc_pd_power_on; + + if (pd->flags & (PD_CPU | PD_NO_CR)) { + /* Skip CPUs (handled by SMP code) and areas without control */ + pr_debug("%s: Not touching %s\n", __func__, genpd->name); + goto finalize; + } + + if (!rcar_sysc_power_is_off(&pd->ch)) { + pr_debug("%s: %s is already powered\n", __func__, genpd->name); + goto finalize; + } + + rcar_sysc_power(&pd->ch, true); + +finalize: + error = pm_genpd_init(genpd, &simple_qos_governor, false); + if (error) + pr_err("Failed to init PM domain %s: %d\n", name, error); + + return error; +} + +static const struct of_device_id rcar_sysc_matches[] __initconst = { +#ifdef CONFIG_SYSC_R8A7742 + { .compatible = "renesas,r8a7742-sysc", .data = &r8a7742_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7743 + { .compatible = "renesas,r8a7743-sysc", .data = &r8a7743_sysc_info }, + /* RZ/G1N is identical to RZ/G2M w.r.t. power domains. */ + { .compatible = "renesas,r8a7744-sysc", .data = &r8a7743_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7745 + { .compatible = "renesas,r8a7745-sysc", .data = &r8a7745_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77470 + { .compatible = "renesas,r8a77470-sysc", .data = &r8a77470_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A774A1 + { .compatible = "renesas,r8a774a1-sysc", .data = &r8a774a1_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A774B1 + { .compatible = "renesas,r8a774b1-sysc", .data = &r8a774b1_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A774C0 + { .compatible = "renesas,r8a774c0-sysc", .data = &r8a774c0_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A774E1 + { .compatible = "renesas,r8a774e1-sysc", .data = &r8a774e1_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7779 + { .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7790 + { .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7791 + { .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info }, + /* R-Car M2-N is identical to R-Car M2-W w.r.t. power domains. */ + { .compatible = "renesas,r8a7793-sysc", .data = &r8a7791_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7792 + { .compatible = "renesas,r8a7792-sysc", .data = &r8a7792_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7794 + { .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A7795 + { .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77960 + { .compatible = "renesas,r8a7796-sysc", .data = &r8a77960_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77961 + { .compatible = "renesas,r8a77961-sysc", .data = &r8a77961_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77965 + { .compatible = "renesas,r8a77965-sysc", .data = &r8a77965_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77970 + { .compatible = "renesas,r8a77970-sysc", .data = &r8a77970_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77980 + { .compatible = "renesas,r8a77980-sysc", .data = &r8a77980_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77990 + { .compatible = "renesas,r8a77990-sysc", .data = &r8a77990_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A77995 + { .compatible = "renesas,r8a77995-sysc", .data = &r8a77995_sysc_info }, +#endif + { /* sentinel */ } +}; + +struct rcar_pm_domains { + struct genpd_onecell_data onecell_data; + struct generic_pm_domain *domains[RCAR_PD_ALWAYS_ON + 1]; +}; + +static struct genpd_onecell_data *rcar_sysc_onecell_data; + +static int __init rcar_sysc_pd_init(void) +{ + const struct rcar_sysc_info *info; + const struct of_device_id *match; + struct rcar_pm_domains *domains; + struct device_node *np; + void __iomem *base; + unsigned int i; + int error; + + np = of_find_matching_node_and_match(NULL, rcar_sysc_matches, &match); + if (!np) + return -ENODEV; + + info = match->data; + + if (info->init) { + error = info->init(); + if (error) + goto out_put; + } + + has_cpg_mstp = of_find_compatible_node(NULL, NULL, + "renesas,cpg-mstp-clocks"); + + base = of_iomap(np, 0); + if (!base) { + pr_warn("%pOF: Cannot map regs\n", np); + error = -ENOMEM; + goto out_put; + } + + rcar_sysc_base = base; + + /* Optional External Request Mask Register */ + rcar_sysc_extmask_offs = info->extmask_offs; + rcar_sysc_extmask_val = info->extmask_val; + + domains = kzalloc(sizeof(*domains), GFP_KERNEL); + if (!domains) { + error = -ENOMEM; + goto out_put; + } + + domains->onecell_data.domains = domains->domains; + domains->onecell_data.num_domains = ARRAY_SIZE(domains->domains); + rcar_sysc_onecell_data = &domains->onecell_data; + + for (i = 0; i < info->num_areas; i++) { + const struct rcar_sysc_area *area = &info->areas[i]; + struct rcar_sysc_pd *pd; + + if (!area->name) { + /* Skip NULLified area */ + continue; + } + + pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL); + if (!pd) { + error = -ENOMEM; + goto out_put; + } + + strcpy(pd->name, area->name); + pd->genpd.name = pd->name; + pd->ch.chan_offs = area->chan_offs; + pd->ch.chan_bit = area->chan_bit; + pd->ch.isr_bit = area->isr_bit; + pd->flags = area->flags; + + error = rcar_sysc_pd_setup(pd); + if (error) + goto out_put; + + domains->domains[area->isr_bit] = &pd->genpd; + + if (area->parent < 0) + continue; + + error = pm_genpd_add_subdomain(domains->domains[area->parent], + &pd->genpd); + if (error) { + pr_warn("Failed to add PM subdomain %s to parent %u\n", + area->name, area->parent); + goto out_put; + } + } + + error = of_genpd_add_provider_onecell(np, &domains->onecell_data); + +out_put: + of_node_put(np); + return error; +} +early_initcall(rcar_sysc_pd_init); + +void __init rcar_sysc_nullify(struct rcar_sysc_area *areas, + unsigned int num_areas, u8 id) +{ + unsigned int i; + + for (i = 0; i < num_areas; i++) + if (areas[i].isr_bit == id) { + areas[i].name = NULL; + return; + } +} + +#ifdef CONFIG_ARCH_R8A7779 +static int rcar_sysc_power_cpu(unsigned int idx, bool on) +{ + struct generic_pm_domain *genpd; + struct rcar_sysc_pd *pd; + unsigned int i; + + if (!rcar_sysc_onecell_data) + return -ENODEV; + + for (i = 0; i < rcar_sysc_onecell_data->num_domains; i++) { + genpd = rcar_sysc_onecell_data->domains[i]; + if (!genpd) + continue; + + pd = to_rcar_pd(genpd); + if (!(pd->flags & PD_CPU) || pd->ch.chan_bit != idx) + continue; + + return rcar_sysc_power(&pd->ch, on); + } + + return -ENOENT; +} + +int rcar_sysc_power_down_cpu(unsigned int cpu) +{ + return rcar_sysc_power_cpu(cpu, false); +} + +int rcar_sysc_power_up_cpu(unsigned int cpu) +{ + return rcar_sysc_power_cpu(cpu, true); +} +#endif /* CONFIG_ARCH_R8A7779 */ |