blob: 79dbc770895f4b6d01f17b6e4ce63db58c61d40a [file] [log] [blame]
/*
* R-Car SYSC Power management support
*
* Copyright (C) 2014 Magnus Damm
* Copyright (C) 2015-2016 Glider bvba
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#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 */
static void __iomem *rcar_sysc_base;
static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
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);
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:
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;
}
int rcar_sysc_power_down(const struct rcar_sysc_ch *sysc_ch)
{
return rcar_sysc_power(sysc_ch, false);
}
int rcar_sysc_power_up(const struct rcar_sysc_ch *sysc_ch)
{
return rcar_sysc_power(sysc_ch, true);
}
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;
}
void __iomem *rcar_sysc_init(phys_addr_t base)
{
rcar_sysc_base = ioremap_nocache(base, PAGE_SIZE);
if (!rcar_sysc_base)
panic("unable to ioremap R-Car SYSC hardware block\n");
return rcar_sysc_base;
}
struct rcar_sysc_pd {
struct generic_pm_domain genpd;
struct rcar_sysc_ch ch;
unsigned int flags;
char name[0];
};
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);
if (pd->flags & PD_NO_CR) {
pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
return -EBUSY;
}
if (pd->flags & PD_BUSY) {
pr_debug("%s: %s busy\n", __func__, genpd->name);
return -EBUSY;
}
return rcar_sysc_power_down(&pd->ch);
}
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);
if (pd->flags & PD_NO_CR) {
pr_debug("%s: Cannot control %s\n", __func__, genpd->name);
return 0;
}
return rcar_sysc_power_up(&pd->ch);
}
static bool has_cpg_mstp;
static void __init rcar_sysc_pd_setup(struct rcar_sysc_pd *pd)
{
struct generic_pm_domain *genpd = &pd->genpd;
const char *name = pd->genpd.name;
struct dev_power_governor *gov = &simple_qos_governor;
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");
pd->flags |= PD_BUSY;
gov = &pm_domain_always_on_gov;
} 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");
pd->flags |= PD_BUSY;
gov = &pm_domain_always_on_gov;
} else if (pd->flags & PD_NO_CR) {
/*
* This domain cannot be turned off.
*/
pd->flags |= PD_BUSY;
gov = &pm_domain_always_on_gov;
}
if (!(pd->flags & (PD_CPU | PD_SCU))) {
/* Enable Clock Domain for I/O devices */
genpd->flags = GENPD_FLAG_PM_CLK;
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_up(&pd->ch);
finalize:
pm_genpd_init(genpd, gov, false);
}
static const struct of_device_id rcar_sysc_matches[] = {
#ifdef CONFIG_ARCH_R8A7779
{ .compatible = "renesas,r8a7779-sysc", .data = &r8a7779_sysc_info },
#endif
#ifdef CONFIG_ARCH_R8A7790
{ .compatible = "renesas,r8a7790-sysc", .data = &r8a7790_sysc_info },
#endif
#ifdef CONFIG_ARCH_R8A7791
{ .compatible = "renesas,r8a7791-sysc", .data = &r8a7791_sysc_info },
#endif
#ifdef CONFIG_ARCH_R8A7793
/* 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_ARCH_R8A7794
{ .compatible = "renesas,r8a7794-sysc", .data = &r8a7794_sysc_info },
#endif
#ifdef CONFIG_ARCH_R8A7795
{ .compatible = "renesas,r8a7795-sysc", .data = &r8a7795_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 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;
u32 syscier, syscimr;
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;
has_cpg_mstp = of_find_compatible_node(NULL, NULL,
"renesas,cpg-mstp-clocks");
base = of_iomap(np, 0);
if (!base) {
pr_warn("%s: Cannot map regs\n", np->full_name);
error = -ENOMEM;
goto out_put;
}
rcar_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);
for (i = 0, syscier = 0; i < info->num_areas; i++)
syscier |= BIT(info->areas[i].isr_bit);
/*
* Mask all interrupt sources to prevent the CPU from receiving them.
* Make sure not to clear reserved bits that were set before.
*/
syscimr = ioread32(base + SYSCIMR);
syscimr |= syscier;
pr_debug("%s: syscimr = 0x%08x\n", np->full_name, syscimr);
iowrite32(syscimr, base + SYSCIMR);
/*
* SYSC needs all interrupt sources enabled to control power.
*/
pr_debug("%s: syscier = 0x%08x\n", np->full_name, syscier);
iowrite32(syscier, base + SYSCIER);
for (i = 0; i < info->num_areas; i++) {
const struct rcar_sysc_area *area = &info->areas[i];
struct rcar_sysc_pd *pd;
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;
rcar_sysc_pd_setup(pd);
if (area->parent >= 0)
pm_genpd_add_subdomain(domains->domains[area->parent],
&pd->genpd);
domains->domains[area->isr_bit] = &pd->genpd;
}
of_genpd_add_provider_onecell(np, &domains->onecell_data);
out_put:
of_node_put(np);
return error;
}
early_initcall(rcar_sysc_pd_init);