diff options
Diffstat (limited to 'drivers/soc/renesas')
| -rw-r--r-- | drivers/soc/renesas/Makefile | 5 | ||||
| -rw-r--r-- | drivers/soc/renesas/rcar-sysc.c | 164 |
2 files changed, 169 insertions, 0 deletions
diff --git a/drivers/soc/renesas/Makefile b/drivers/soc/renesas/Makefile new file mode 100644 index 000000000000..2b64f6c94681 --- /dev/null +++ b/drivers/soc/renesas/Makefile @@ -0,0 +1,5 @@ +obj-$(CONFIG_ARCH_R8A7779) += rcar-sysc.o +obj-$(CONFIG_ARCH_R8A7790) += rcar-sysc.o +obj-$(CONFIG_ARCH_R8A7791) += rcar-sysc.o +obj-$(CONFIG_ARCH_R8A7793) += rcar-sysc.o +obj-$(CONFIG_ARCH_R8A7794) += rcar-sysc.o diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c new file mode 100644 index 000000000000..d59bcdf78f0b --- /dev/null +++ b/drivers/soc/renesas/rcar-sysc.c @@ -0,0 +1,164 @@ +/* + * 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 <linux/io.h> +#include <linux/soc/renesas/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 + */ +#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; +} |