diff options
Diffstat (limited to 'kernel/arch/arm/mach-ux500/pm.c')
| -rw-r--r-- | kernel/arch/arm/mach-ux500/pm.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-ux500/pm.c b/kernel/arch/arm/mach-ux500/pm.c new file mode 100644 index 000000000..2cb587b50 --- /dev/null +++ b/kernel/arch/arm/mach-ux500/pm.c @@ -0,0 +1,198 @@ +/* + * 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" +#include "pm_domains.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); + + /* Initialize ux500 power domains */ + ux500_pm_domains_init(); +} |