blob: 4092ad16e0a42a266e5b7675e2d60662fd958417 [file] [log] [blame]
/*
* R-Car SYSC Power management support
*
* Copyright (C) 2014 Magnus Damm
*
* 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/delay.h>
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <asm/io.h>
#include "pm-rcar.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
*/
#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
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 domain %d: %08x -> %d\n",
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);
}
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;
}