diff options
Diffstat (limited to 'arch/arm/mach-ux500/pm.c')
| -rw-r--r-- | arch/arm/mach-ux500/pm.c | 167 | 
1 files changed, 167 insertions, 0 deletions
| diff --git a/arch/arm/mach-ux500/pm.c b/arch/arm/mach-ux500/pm.c new file mode 100644 index 00000000000..1a468f0fd22 --- /dev/null +++ b/arch/arm/mach-ux500/pm.c @@ -0,0 +1,167 @@ +/* + * 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. + * 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/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; +} + +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(); +} |