// 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 1
#define PDRESR_RETRIES 10000
#define PDRESR_DELAY_US 1
#define SYSCISCR_TIMEOUT 10000
#define SYSCISCR_DELAY_US 1
#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),
SYSCISCR_DELAY_US, SYSCISCR_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),
SYSCISCR_DELAY_US, SYSCISCR_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
#ifdef CONFIG_SYSC_R8A779H0
{ .compatible = "renesas,r8a779h0-sysc", .data = &r8a779h0_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);
Codebase Browser
linux