143 lines
3.0 KiB
C
143 lines
3.0 KiB
C
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/*
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* R-Car SYSC Power management support
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*
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* Copyright (C) 2014 Magnus Damm
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/mm.h>
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#include <linux/spinlock.h>
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#include <asm/io.h>
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#include <mach/pm-rcar.h>
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static void __iomem *rcar_sysc_base;
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/* SYSC */
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#define SYSCSR 0x00
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#define SYSCISR 0x04
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#define SYSCISCR 0x08
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#define PWRSR_OFFS 0x00
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#define PWROFFCR_OFFS 0x04
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#define PWRONCR_OFFS 0x0c
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#define PWRER_OFFS 0x14
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#define SYSCSR_RETRIES 100
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#define SYSCSR_DELAY_US 1
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#define SYSCISR_RETRIES 1000
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#define SYSCISR_DELAY_US 1
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#if defined(CONFIG_PM) || defined(CONFIG_SMP)
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static DEFINE_SPINLOCK(rcar_sysc_lock); /* SMP CPUs + I/O devices */
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static int rcar_sysc_pwr_on_off(struct rcar_sysc_ch *sysc_ch,
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int sr_bit, int reg_offs)
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{
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int k;
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for (k = 0; k < SYSCSR_RETRIES; k++) {
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if (ioread32(rcar_sysc_base + SYSCSR) & (1 << sr_bit))
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break;
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udelay(SYSCSR_DELAY_US);
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}
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if (k == SYSCSR_RETRIES)
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return -EAGAIN;
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iowrite32(1 << sysc_ch->chan_bit,
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rcar_sysc_base + sysc_ch->chan_offs + reg_offs);
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return 0;
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}
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static int rcar_sysc_pwr_off(struct rcar_sysc_ch *sysc_ch)
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{
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return rcar_sysc_pwr_on_off(sysc_ch, 0, PWROFFCR_OFFS);
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}
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static int rcar_sysc_pwr_on(struct rcar_sysc_ch *sysc_ch)
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{
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return rcar_sysc_pwr_on_off(sysc_ch, 1, PWRONCR_OFFS);
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}
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static int rcar_sysc_update(struct rcar_sysc_ch *sysc_ch,
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int (*on_off_fn)(struct rcar_sysc_ch *))
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{
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unsigned int isr_mask = 1 << sysc_ch->isr_bit;
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unsigned int chan_mask = 1 << sysc_ch->chan_bit;
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unsigned int status;
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unsigned long flags;
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int ret = 0;
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int k;
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spin_lock_irqsave(&rcar_sysc_lock, flags);
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iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
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do {
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ret = on_off_fn(sysc_ch);
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if (ret)
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goto out;
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status = ioread32(rcar_sysc_base +
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sysc_ch->chan_offs + PWRER_OFFS);
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} while (status & chan_mask);
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for (k = 0; k < SYSCISR_RETRIES; k++) {
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if (ioread32(rcar_sysc_base + SYSCISR) & isr_mask)
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break;
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udelay(SYSCISR_DELAY_US);
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}
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if (k == SYSCISR_RETRIES)
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ret = -EIO;
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iowrite32(isr_mask, rcar_sysc_base + SYSCISCR);
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out:
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spin_unlock_irqrestore(&rcar_sysc_lock, flags);
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pr_debug("sysc power domain %d: %08x -> %d\n",
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sysc_ch->isr_bit, ioread32(rcar_sysc_base + SYSCISR), ret);
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return ret;
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}
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int rcar_sysc_power_down(struct rcar_sysc_ch *sysc_ch)
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{
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return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_off);
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}
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int rcar_sysc_power_up(struct rcar_sysc_ch *sysc_ch)
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{
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return rcar_sysc_update(sysc_ch, rcar_sysc_pwr_on);
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}
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bool rcar_sysc_power_is_off(struct rcar_sysc_ch *sysc_ch)
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{
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unsigned int st;
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st = ioread32(rcar_sysc_base + sysc_ch->chan_offs + PWRSR_OFFS);
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if (st & (1 << sysc_ch->chan_bit))
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return true;
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return false;
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}
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void __iomem *rcar_sysc_init(phys_addr_t base)
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{
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rcar_sysc_base = ioremap_nocache(base, PAGE_SIZE);
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if (!rcar_sysc_base)
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panic("unable to ioremap R-Car SYSC hardware block\n");
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return rcar_sysc_base;
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}
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#endif /* CONFIG_PM || CONFIG_SMP */
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