diff options
Diffstat (limited to 'arch/arm/mach-shmobile/pm-rcar.c')
-rw-r--r-- | arch/arm/mach-shmobile/pm-rcar.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/pm-rcar.c b/arch/arm/mach-shmobile/pm-rcar.c new file mode 100644 index 000000000000..1f465a12d1b1 --- /dev/null +++ b/arch/arm/mach-shmobile/pm-rcar.c @@ -0,0 +1,141 @@ +/* + * 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 <mach/pm-rcar.h> + +/* SYSC */ +#define SYSCSR 0x00 +#define SYSCISR 0x04 +#define SYSCISCR 0x08 + +#define PWRSR_OFFS 0x00 +#define PWROFFCR_OFFS 0x04 +#define PWRONCR_OFFS 0x0c +#define PWRER_OFFS 0x14 + +#define SYSCSR_RETRIES 100 +#define SYSCSR_DELAY_US 1 + +#define SYSCISR_RETRIES 1000 +#define SYSCISR_DELAY_US 1 + +#if defined(CONFIG_PM) || defined(CONFIG_SMP) + +static void __iomem *rcar_sysc_base; +static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */ + +static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch, + int sr_bit, int reg_offs) +{ + int k; + + for (k = 0; k < SYSCSR_RETRIES; k++) { + if (ioread32(rcar_sysc_base + SYSCSR) & (1 << sr_bit)) + break; + udelay(SYSCSR_DELAY_US); + } + + if (k == SYSCSR_RETRIES) + return -EAGAIN; + + iowrite32(1 << sysc_ch->chan_bit, + rcar_sysc_base + sysc_ch->chan_offs + reg_offs); + + return 0; +} + +static int rcar_sysc_pwr_off(struct rcar_sysc_ch *sysc_ch) +{ + return rcar_sysc_pwr_on_off(sysc_ch, 0, PWROFFCR_OFFS); +} + +static int rcar_sysc_pwr_on(struct rcar_sysc_ch *sysc_ch) +{ + return rcar_sysc_pwr_on_off(sysc_ch, 1, PWRONCR_OFFS); +} + +static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch, + int (*on_off_fn)(struct rcar_sysc_ch *)) +{ + unsigned int isr_mask = 1 << sysc_ch->isr_bit; + unsigned int chan_mask = 1 << 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); + + do { + ret = on_off_fn(sysc_ch); + if (ret) + goto out; + + status = ioread32(rcar_sysc_base + + sysc_ch->chan_offs + PWRER_OFFS); + } while (status & chan_mask); + + 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(struct rcar_sysc_ch *sysc_ch) +{ + return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_off); +} + +int rcar_sysc_power_up(struct rcar_sysc_ch *sysc_ch) +{ + return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_on); +} + +bool rcar_sysc_power_is_off(struct rcar_sysc_ch *sysc_ch) +{ + unsigned int st; + + st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS); + if (st & (1 << 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; +} + +#endif /* CONFIG_PM || CONFIG_SMP */ |