pm.c
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/*
* Copyright (C) ST-Ericsson SA 2010-2013
* Author: Rickard Andersson <rickard.andersson@stericsson.com> for
* ST-Ericsson.
* Author: Daniel Lezcano <daniel.lezcano@linaro.org> for Linaro.
* Author: Ulf Hansson <ulf.hansson@linaro.org> for Linaro.
*
* License terms: GNU General Public License (GPL) version 2
*
*/
#include <linux/kernel.h>
#include <linux/irqchip/arm-gic.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/suspend.h>
#include <linux/platform_data/arm-ux500-pm.h>
#include "db8500-regs.h"
/* ARM WFI Standby signal register */
#define PRCM_ARM_WFI_STANDBY (prcmu_base + 0x130)
#define PRCM_ARM_WFI_STANDBY_WFI0 0x08
#define PRCM_ARM_WFI_STANDBY_WFI1 0x10
#define PRCM_IOCR (prcmu_base + 0x310)
#define PRCM_IOCR_IOFORCE 0x1
/* Dual A9 core interrupt management unit registers */
#define PRCM_A9_MASK_REQ (prcmu_base + 0x328)
#define PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ 0x1
#define PRCM_A9_MASK_ACK (prcmu_base + 0x32c)
#define PRCM_ARMITMSK31TO0 (prcmu_base + 0x11c)
#define PRCM_ARMITMSK63TO32 (prcmu_base + 0x120)
#define PRCM_ARMITMSK95TO64 (prcmu_base + 0x124)
#define PRCM_ARMITMSK127TO96 (prcmu_base + 0x128)
#define PRCM_POWER_STATE_VAL (prcmu_base + 0x25C)
#define PRCM_ARMITVAL31TO0 (prcmu_base + 0x260)
#define PRCM_ARMITVAL63TO32 (prcmu_base + 0x264)
#define PRCM_ARMITVAL95TO64 (prcmu_base + 0x268)
#define PRCM_ARMITVAL127TO96 (prcmu_base + 0x26C)
static void __iomem *prcmu_base;
/* This function decouple the gic from the prcmu */
int prcmu_gic_decouple(void)
{
u32 val = readl(PRCM_A9_MASK_REQ);
/* Set bit 0 register value to 1 */
writel(val | PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ,
PRCM_A9_MASK_REQ);
/* Make sure the register is updated */
readl(PRCM_A9_MASK_REQ);
/* Wait a few cycles for the gic mask completion */
udelay(1);
return 0;
}
/* This function recouple the gic with the prcmu */
int prcmu_gic_recouple(void)
{
u32 val = readl(PRCM_A9_MASK_REQ);
/* Set bit 0 register value to 0 */
writel(val & ~PRCM_A9_MASK_REQ_PRCM_A9_MASK_REQ, PRCM_A9_MASK_REQ);
return 0;
}
#define PRCMU_GIC_NUMBER_REGS 5
/*
* This function checks if there are pending irq on the gic. It only
* makes sense if the gic has been decoupled before with the
* db8500_prcmu_gic_decouple function. Disabling an interrupt only
* disables the forwarding of the interrupt to any CPU interface. It
* does not prevent the interrupt from changing state, for example
* becoming pending, or active and pending if it is already
* active. Hence, we have to check the interrupt is pending *and* is
* active.
*/
bool prcmu_gic_pending_irq(void)
{
u32 pr; /* Pending register */
u32 er; /* Enable register */
void __iomem *dist_base = __io_address(U8500_GIC_DIST_BASE);
int i;
/* 5 registers. STI & PPI not skipped */
for (i = 0; i < PRCMU_GIC_NUMBER_REGS; i++) {
pr = readl_relaxed(dist_base + GIC_DIST_PENDING_SET + i * 4);
er = readl_relaxed(dist_base + GIC_DIST_ENABLE_SET + i * 4);
if (pr & er)
return true; /* There is a pending interrupt */
}
return false;
}
/*
* This function checks if there are pending interrupt on the
* prcmu which has been delegated to monitor the irqs with the
* db8500_prcmu_copy_gic_settings function.
*/
bool prcmu_pending_irq(void)
{
u32 it, im;
int i;
for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
it = readl(PRCM_ARMITVAL31TO0 + i * 4);
im = readl(PRCM_ARMITMSK31TO0 + i * 4);
if (it & im)
return true; /* There is a pending interrupt */
}
return false;
}
/*
* This function checks if the specified cpu is in in WFI. It's usage
* makes sense only if the gic is decoupled with the db8500_prcmu_gic_decouple
* function. Of course passing smp_processor_id() to this function will
* always return false...
*/
bool prcmu_is_cpu_in_wfi(int cpu)
{
return readl(PRCM_ARM_WFI_STANDBY) & cpu ? PRCM_ARM_WFI_STANDBY_WFI1 :
PRCM_ARM_WFI_STANDBY_WFI0;
}
/*
* This function copies the gic SPI settings to the prcmu in order to
* monitor them and abort/finish the retention/off sequence or state.
*/
int prcmu_copy_gic_settings(void)
{
u32 er; /* Enable register */
void __iomem *dist_base = __io_address(U8500_GIC_DIST_BASE);
int i;
/* We skip the STI and PPI */
for (i = 0; i < PRCMU_GIC_NUMBER_REGS - 1; i++) {
er = readl_relaxed(dist_base +
GIC_DIST_ENABLE_SET + (i + 1) * 4);
writel(er, PRCM_ARMITMSK31TO0 + i * 4);
}
return 0;
}
#ifdef CONFIG_SUSPEND
static int ux500_suspend_enter(suspend_state_t state)
{
cpu_do_idle();
return 0;
}
static int ux500_suspend_valid(suspend_state_t state)
{
return state == PM_SUSPEND_MEM || state == PM_SUSPEND_STANDBY;
}
static const struct platform_suspend_ops ux500_suspend_ops = {
.enter = ux500_suspend_enter,
.valid = ux500_suspend_valid,
};
#define UX500_SUSPEND_OPS (&ux500_suspend_ops)
#else
#define UX500_SUSPEND_OPS NULL
#endif
void __init ux500_pm_init(u32 phy_base, u32 size)
{
prcmu_base = ioremap(phy_base, size);
if (!prcmu_base) {
pr_err("could not remap PRCMU for PM functions\n");
return;
}
/*
* On watchdog reboot the GIC is in some cases decoupled.
* This will make sure that the GIC is correctly configured.
*/
prcmu_gic_recouple();
/* Set up ux500 suspend callbacks. */
suspend_set_ops(UX500_SUSPEND_OPS);
}