diff options
Diffstat (limited to 'drivers/pmdomain/renesas/rcar-gen4-sysc.c')
| -rw-r--r-- | drivers/pmdomain/renesas/rcar-gen4-sysc.c | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/pmdomain/renesas/rcar-gen4-sysc.c b/drivers/pmdomain/renesas/rcar-gen4-sysc.c new file mode 100644 index 000000000000..9e5e6e077abc --- /dev/null +++ b/drivers/pmdomain/renesas/rcar-gen4-sysc.c @@ -0,0 +1,379 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * R-Car Gen4 SYSC Power management support + * + * Copyright (C) 2021 Renesas Electronics Corp. + */ + +#include <linux/bits.h> +#include <linux/clk/renesas.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.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/types.h> + +#include "rcar-gen4-sysc.h" + +/* SYSC Common */ +#define SYSCSR 0x000 /* SYSC Status Register */ +#define SYSCPONSR(x) (0x800 + ((x) * 0x4)) /* Power-ON Status Register 0 */ +#define SYSCPOFFSR(x) (0x808 + ((x) * 0x4)) /* Power-OFF Status Register */ +#define SYSCISCR(x) (0x810 + ((x) * 0x4)) /* Interrupt Status/Clear Register */ +#define SYSCIER(x) (0x820 + ((x) * 0x4)) /* Interrupt Enable Register */ +#define SYSCIMR(x) (0x830 + ((x) * 0x4)) /* Interrupt Mask Register */ + +/* Power Domain Registers */ +#define PDRSR(n) (0x1000 + ((n) * 0x40)) +#define PDRONCR(n) (0x1004 + ((n) * 0x40)) +#define PDROFFCR(n) (0x1008 + ((n) * 0x40)) +#define PDRESR(n) (0x100C + ((n) * 0x40)) + +/* PWRON/PWROFF */ +#define PWRON_PWROFF BIT(0) /* Power-ON/OFF request */ + +/* PDRESR */ +#define PDRESR_ERR BIT(0) + +/* PDRSR */ +#define PDRSR_OFF BIT(0) /* Power-OFF state */ +#define PDRSR_ON BIT(4) /* Power-ON state */ +#define PDRSR_OFF_STATE BIT(8) /* Processing Power-OFF sequence */ +#define PDRSR_ON_STATE BIT(12) /* Processing Power-ON sequence */ + +#define SYSCSR_BUSY GENMASK(1, 0) /* All bit sets is not busy */ + +#define SYSCSR_TIMEOUT 10000 +#define SYSCSR_DELAY_US 10 + +#define PDRESR_RETRIES 1000 +#define PDRESR_DELAY_US 10 + +#define SYSCISR_TIMEOUT 10000 +#define SYSCISR_DELAY_US 10 + +#define RCAR_GEN4_PD_ALWAYS_ON 64 +#define NUM_DOMAINS_EACH_REG BITS_PER_TYPE(u32) + +static void __iomem *rcar_gen4_sysc_base; +static DEFINE_SPINLOCK(rcar_gen4_sysc_lock); /* SMP CPUs + I/O devices */ + +static int rcar_gen4_sysc_pwr_on_off(u8 pdr, bool on) +{ + unsigned int reg_offs; + u32 val; + int ret; + + if (on) + reg_offs = PDRONCR(pdr); + else + reg_offs = PDROFFCR(pdr); + + /* Wait until SYSC is ready to accept a power request */ + ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCSR, val, + (val & SYSCSR_BUSY) == SYSCSR_BUSY, + SYSCSR_DELAY_US, SYSCSR_TIMEOUT); + if (ret < 0) + return -EAGAIN; + + /* Submit power shutoff or power resume request */ + iowrite32(PWRON_PWROFF, rcar_gen4_sysc_base + reg_offs); + + return 0; +} + +static int clear_irq_flags(unsigned int reg_idx, unsigned int isr_mask) +{ + u32 val; + int ret; + + iowrite32(isr_mask, rcar_gen4_sysc_base + SYSCISCR(reg_idx)); + + ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx), + val, !(val & isr_mask), + SYSCISR_DELAY_US, SYSCISR_TIMEOUT); + if (ret < 0) { + pr_err("\n %s : Can not clear IRQ flags in SYSCISCR", __func__); + return -EIO; + } + + return 0; +} + +static int rcar_gen4_sysc_power(u8 pdr, bool on) +{ + unsigned int isr_mask; + unsigned int reg_idx, bit_idx; + unsigned int status; + unsigned long flags; + int ret = 0; + u32 val; + int k; + + spin_lock_irqsave(&rcar_gen4_sysc_lock, flags); + + reg_idx = pdr / NUM_DOMAINS_EACH_REG; + bit_idx = pdr % NUM_DOMAINS_EACH_REG; + + isr_mask = BIT(bit_idx); + + /* + * The interrupt source needs to be enabled, but masked, to prevent the + * CPU from receiving it. + */ + iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIER(reg_idx)) | isr_mask, + rcar_gen4_sysc_base + SYSCIER(reg_idx)); + iowrite32(ioread32(rcar_gen4_sysc_base + SYSCIMR(reg_idx)) | isr_mask, + rcar_gen4_sysc_base + SYSCIMR(reg_idx)); + + ret = clear_irq_flags(reg_idx, isr_mask); + if (ret) + goto out; + + /* Submit power shutoff or resume request until it was accepted */ + for (k = 0; k < PDRESR_RETRIES; k++) { + ret = rcar_gen4_sysc_pwr_on_off(pdr, on); + if (ret) + goto out; + + status = ioread32(rcar_gen4_sysc_base + PDRESR(pdr)); + if (!(status & PDRESR_ERR)) + break; + + udelay(PDRESR_DELAY_US); + } + + if (k == PDRESR_RETRIES) { + ret = -EIO; + goto out; + } + + /* Wait until the power shutoff or resume request has completed * */ + ret = readl_poll_timeout_atomic(rcar_gen4_sysc_base + SYSCISCR(reg_idx), + val, (val & isr_mask), + SYSCISR_DELAY_US, SYSCISR_TIMEOUT); + if (ret < 0) { + ret = -EIO; + goto out; + } + + /* Clear interrupt flags */ + ret = clear_irq_flags(reg_idx, isr_mask); + if (ret) + goto out; + + out: + spin_unlock_irqrestore(&rcar_gen4_sysc_lock, flags); + + pr_debug("sysc power %s domain %d: %08x -> %d\n", on ? "on" : "off", + pdr, ioread32(rcar_gen4_sysc_base + SYSCISCR(reg_idx)), ret); + return ret; +} + +static bool rcar_gen4_sysc_power_is_off(u8 pdr) +{ + unsigned int st; + + st = ioread32(rcar_gen4_sysc_base + PDRSR(pdr)); + + if (st & PDRSR_OFF) + return true; + + return false; +} + +struct rcar_gen4_sysc_pd { + struct generic_pm_domain genpd; + u8 pdr; + unsigned int flags; + char name[]; +}; + +static inline struct rcar_gen4_sysc_pd *to_rcar_gen4_pd(struct generic_pm_domain *d) +{ + return container_of(d, struct rcar_gen4_sysc_pd, genpd); +} + +static int rcar_gen4_sysc_pd_power_off(struct generic_pm_domain *genpd) +{ + struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd); + + pr_debug("%s: %s\n", __func__, genpd->name); + return rcar_gen4_sysc_power(pd->pdr, false); +} + +static int rcar_gen4_sysc_pd_power_on(struct generic_pm_domain *genpd) +{ + struct rcar_gen4_sysc_pd *pd = to_rcar_gen4_pd(genpd); + + pr_debug("%s: %s\n", __func__, genpd->name); + return rcar_gen4_sysc_power(pd->pdr, true); +} + +static int __init rcar_gen4_sysc_pd_setup(struct rcar_gen4_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; + genpd->attach_dev = cpg_mssr_attach_dev; + genpd->detach_dev = cpg_mssr_detach_dev; + } + + genpd->power_off = rcar_gen4_sysc_pd_power_off; + genpd->power_on = rcar_gen4_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_gen4_sysc_power_is_off(pd->pdr)) { + pr_debug("%s: %s is already powered\n", __func__, genpd->name); + goto finalize; + } + + rcar_gen4_sysc_power(pd->pdr, 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_gen4_sysc_matches[] __initconst = { +#ifdef CONFIG_SYSC_R8A779A0 + { .compatible = "renesas,r8a779a0-sysc", .data = &r8a779a0_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A779F0 + { .compatible = "renesas,r8a779f0-sysc", .data = &r8a779f0_sysc_info }, +#endif +#ifdef CONFIG_SYSC_R8A779G0 + { .compatible = "renesas,r8a779g0-sysc", .data = &r8a779g0_sysc_info }, +#endif + { /* sentinel */ } +}; + +struct rcar_gen4_pm_domains { + struct genpd_onecell_data onecell_data; + struct generic_pm_domain *domains[RCAR_GEN4_PD_ALWAYS_ON + 1]; +}; + +static struct genpd_onecell_data *rcar_gen4_sysc_onecell_data; + +static int __init rcar_gen4_sysc_pd_init(void) +{ + const struct rcar_gen4_sysc_info *info; + const struct of_device_id *match; + struct rcar_gen4_pm_domains *domains; + struct device_node *np; + void __iomem *base; + unsigned int i; + int error; + + np = of_find_matching_node_and_match(NULL, rcar_gen4_sysc_matches, &match); + if (!np) + return -ENODEV; + + info = match->data; + + base = of_iomap(np, 0); + if (!base) { + pr_warn("%pOF: Cannot map regs\n", np); + error = -ENOMEM; + goto out_put; + } + + rcar_gen4_sysc_base = base; + + 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_gen4_sysc_onecell_data = &domains->onecell_data; + + for (i = 0; i < info->num_areas; i++) { + const struct rcar_gen4_sysc_area *area = &info->areas[i]; + struct rcar_gen4_sysc_pd *pd; + size_t n; + + if (!area->name) { + /* Skip NULLified area */ + continue; + } + + n = strlen(area->name) + 1; + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL); + if (!pd) { + error = -ENOMEM; + goto out_put; + } + + memcpy(pd->name, area->name, n); + pd->genpd.name = pd->name; + pd->pdr = area->pdr; + pd->flags = area->flags; + + error = rcar_gen4_sysc_pd_setup(pd); + if (error) + goto out_put; + + domains->domains[area->pdr] = &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_gen4_sysc_pd_init); |