/* * OMAP MPUSS low power code * * Copyright (C) 2011 Texas Instruments, Inc. * Santosh Shilimkar * * OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU * Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller, * CPU0 and CPU1 LPRM modules. * CPU0, CPU1 and MPUSS each have there own power domain and * hence multiple low power combinations of MPUSS are possible. * * The CPU0 and CPU1 can't support Closed switch Retention (CSWR) * because the mode is not supported by hw constraints of dormant * mode. While waking up from the dormant mode, a reset signal * to the Cortex-A9 processor must be asserted by the external * power controller. * * With architectural inputs and hardware recommendations, only * below modes are supported from power gain vs latency point of view. * * CPU0 CPU1 MPUSS * ---------------------------------------------- * ON ON ON * ON(Inactive) OFF ON(Inactive) * OFF OFF CSWR * OFF OFF OSWR (*TBD) * OFF OFF OFF* (*TBD) * ---------------------------------------------- * * Note: CPU0 is the master core and it is the last CPU to go down * and first to wake-up when MPUSS low power states are excercised * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "common.h" #include "omap4-sar-layout.h" #include "pm.h" #include "powerdomain.h" #ifdef CONFIG_SMP struct omap4_cpu_pm_info { struct powerdomain *pwrdm; void __iomem *scu_sar_addr; void __iomem *wkup_sar_addr; }; static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info); /* * Program the wakeup routine address for the CPU0 and CPU1 * used for OFF or DORMANT wakeup. */ static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr) { struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id); __raw_writel(addr, pm_info->wkup_sar_addr); } /* * Set the CPUx powerdomain's previous power state */ static inline void set_cpu_next_pwrst(unsigned int cpu_id, unsigned int power_state) { struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id); pwrdm_set_next_pwrst(pm_info->pwrdm, power_state); } /* * Read CPU's previous power state */ static inline unsigned int read_cpu_prev_pwrst(unsigned int cpu_id) { struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id); return pwrdm_read_prev_pwrst(pm_info->pwrdm); } /* * Clear the CPUx powerdomain's previous power state */ static inline void clear_cpu_prev_pwrst(unsigned int cpu_id) { struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id); pwrdm_clear_all_prev_pwrst(pm_info->pwrdm); } /* * Store the SCU power status value to scratchpad memory */ static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state) { struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id); u32 scu_pwr_st; switch (cpu_state) { case PWRDM_POWER_RET: scu_pwr_st = SCU_PM_DORMANT; break; case PWRDM_POWER_OFF: scu_pwr_st = SCU_PM_POWEROFF; break; case PWRDM_POWER_ON: case PWRDM_POWER_INACTIVE: default: scu_pwr_st = SCU_PM_NORMAL; break; } __raw_writel(scu_pwr_st, pm_info->scu_sar_addr); } /** * omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function * The purpose of this function is to manage low power programming * of OMAP4 MPUSS subsystem * @cpu : CPU ID * @power_state: Low power state. */ int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state) { unsigned int save_state = 0; unsigned int wakeup_cpu; if (omap_rev() == OMAP4430_REV_ES1_0) return -ENXIO; switch (power_state) { case PWRDM_POWER_ON: case PWRDM_POWER_INACTIVE: save_state = 0; break; case PWRDM_POWER_OFF: save_state = 1; break; case PWRDM_POWER_RET: default: /* * CPUx CSWR is invalid hardware state. Also CPUx OSWR * doesn't make much scense, since logic is lost and $L1 * needs to be cleaned because of coherency. This makes * CPUx OSWR equivalent to CPUX OFF and hence not supported */ WARN_ON(1); return -ENXIO; } clear_cpu_prev_pwrst(cpu); set_cpu_next_pwrst(cpu, power_state); set_cpu_wakeup_addr(cpu, virt_to_phys(omap4_cpu_resume)); scu_pwrst_prepare(cpu, power_state); /* * Call low level function with targeted low power state. */ cpu_suspend(save_state, omap4_finish_suspend); /* * Restore the CPUx power state to ON otherwise CPUx * power domain can transitions to programmed low power * state while doing WFI outside the low powe code. On * secure devices, CPUx does WFI which can result in * domain transition */ wakeup_cpu = smp_processor_id(); set_cpu_next_pwrst(wakeup_cpu, PWRDM_POWER_ON); return 0; } /** * omap4_hotplug_cpu: OMAP4 CPU hotplug entry * @cpu : CPU ID * @power_state: CPU low power state. */ int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state) { unsigned int cpu_state = 0; if (omap_rev() == OMAP4430_REV_ES1_0) return -ENXIO; if (power_state == PWRDM_POWER_OFF) cpu_state = 1; clear_cpu_prev_pwrst(cpu); set_cpu_next_pwrst(cpu, power_state); set_cpu_wakeup_addr(cpu, virt_to_phys(omap_secondary_startup)); scu_pwrst_prepare(cpu, power_state); /* * CPU never retuns back if targetted power state is OFF mode. * CPU ONLINE follows normal CPU ONLINE ptah via * omap_secondary_startup(). */ omap4_finish_suspend(cpu_state); set_cpu_next_pwrst(cpu, PWRDM_POWER_ON); return 0; } /* * Initialise OMAP4 MPUSS */ int __init omap4_mpuss_init(void) { struct omap4_cpu_pm_info *pm_info; void __iomem *sar_base = omap4_get_sar_ram_base(); if (omap_rev() == OMAP4430_REV_ES1_0) { WARN(1, "Power Management not supported on OMAP4430 ES1.0\n"); return -ENODEV; } /* Initilaise per CPU PM information */ pm_info = &per_cpu(omap4_pm_info, 0x0); pm_info->scu_sar_addr = sar_base + SCU_OFFSET0; pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET; pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm"); if (!pm_info->pwrdm) { pr_err("Lookup failed for CPU0 pwrdm\n"); return -ENODEV; } /* Clear CPU previous power domain state */ pwrdm_clear_all_prev_pwrst(pm_info->pwrdm); /* Initialise CPU0 power domain state to ON */ pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON); pm_info = &per_cpu(omap4_pm_info, 0x1); pm_info->scu_sar_addr = sar_base + SCU_OFFSET1; pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET; pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm"); if (!pm_info->pwrdm) { pr_err("Lookup failed for CPU1 pwrdm\n"); return -ENODEV; } /* Clear CPU previous power domain state */ pwrdm_clear_all_prev_pwrst(pm_info->pwrdm); /* Initialise CPU1 power domain state to ON */ pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON); /* Save device type on scratchpad for low level code to use */ if (omap_type() != OMAP2_DEVICE_TYPE_GP) __raw_writel(1, sar_base + OMAP_TYPE_OFFSET); else __raw_writel(0, sar_base + OMAP_TYPE_OFFSET); return 0; } #endif