Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753515Ab2KGXX6 (ORCPT ); Wed, 7 Nov 2012 18:23:58 -0500 Received: from mail-ob0-f174.google.com ([209.85.214.174]:54796 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751661Ab2KGXX5 (ORCPT ); Wed, 7 Nov 2012 18:23:57 -0500 From: Rob Herring To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Arnd Bergmann , Olof Johansson , Rob Herring , Len Brown , "Rafael J. Wysocki" Subject: [PATCH] cpuidle: add Calxeda SOC idle support Date: Wed, 7 Nov 2012 17:23:42 -0600 Message-Id: <1352330622-13616-1-git-send-email-robherring2@gmail.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6206 Lines: 228 From: Rob Herring Add support for core powergating on Calxeda platforms. Initially, this supports ECX-1000 (highbank), but support will be added for ECX-2000 later. Signed-off-by: Rob Herring Cc: Len Brown Cc: "Rafael J. Wysocki" --- It's not really clear where we want ARM cpuidle drivers. We're moving everything else out of arch/arm, and my understanding is Len doesn't want them in drivers/idle. It seems kind of silly to me to have the framework and drivers in 2 places. I've put this in drivers/cpuidle, but it doesn't make any difference to me. Rob drivers/cpuidle/Kconfig | 10 +++ drivers/cpuidle/Makefile | 2 + drivers/cpuidle/cpuidle-calxeda.c | 161 +++++++++++++++++++++++++++++++++++++ 3 files changed, 173 insertions(+) create mode 100644 drivers/cpuidle/cpuidle-calxeda.c diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index a76b689..d2d007b 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -21,3 +21,13 @@ config CPU_IDLE_GOV_MENU config ARCH_NEEDS_CPU_IDLE_COUPLED def_bool n + +if CPU_IDLE + +config CPU_IDLE_CALXEDA + bool "CPU Idle Driver for Calxeda processors" + depends on ARCH_HIGHBANK + help + Select this to enable cpuidle on Calxeda processors. + +endif diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile index 38c8f69..03ee874 100644 --- a/drivers/cpuidle/Makefile +++ b/drivers/cpuidle/Makefile @@ -4,3 +4,5 @@ obj-y += cpuidle.o driver.o governor.o sysfs.o governors/ obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o + +obj-$(CONFIG_CPU_IDLE_CALXEDA) += cpuidle-calxeda.o diff --git a/drivers/cpuidle/cpuidle-calxeda.c b/drivers/cpuidle/cpuidle-calxeda.c new file mode 100644 index 0000000..e1aab38 --- /dev/null +++ b/drivers/cpuidle/cpuidle-calxeda.c @@ -0,0 +1,161 @@ +/* + * Copyright 2012 Calxeda, Inc. + * + * Based on arch/arm/plat-mxc/cpuidle.c: + * Copyright 2012 Freescale Semiconductor, Inc. + * Copyright 2012 Linaro Ltd. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see . + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +extern void highbank_set_cpu_jump(int cpu, void *jump_addr); +extern void *scu_base_addr; + +static struct cpuidle_device __percpu *calxeda_idle_cpuidle_devices; + +static inline unsigned int get_auxcr(void) +{ + unsigned int val; + asm("mrc p15, 0, %0, c1, c0, 1 @ get AUXCR" : "=r" (val) : : "cc"); + return val; +} + +static inline void set_auxcr(unsigned int val) +{ + asm volatile("mcr p15, 0, %0, c1, c0, 1 @ set AUXCR" + : : "r" (val) : "cc"); + isb(); +} + +static noinline void calxeda_idle_restore(void) +{ + set_cr(get_cr() | CR_C); + set_auxcr(get_auxcr() | 0x40); + scu_power_mode(scu_base_addr, SCU_PM_NORMAL); +} + +static int calxeda_idle_finish(unsigned long val) +{ + /* Already flushed cache, but do it again as the outer cache functions + * dirty the cache with spinlocks */ + flush_cache_all(); + + set_auxcr(get_auxcr() & ~0x40); + set_cr(get_cr() & ~CR_C); + + scu_power_mode(scu_base_addr, SCU_PM_DORMANT); + + cpu_do_idle(); + + /* Restore things if we didn't enter power-gating */ + calxeda_idle_restore(); + return 1; +} + +static int calxeda_pwrdown_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + highbank_set_cpu_jump(smp_processor_id(), cpu_resume); + cpu_suspend(0, calxeda_idle_finish); + return index; +} + +static void calxeda_idle_cpuidle_devices_uninit(void) +{ + int i; + struct cpuidle_device *dev; + + for_each_possible_cpu(i) { + dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, i); + cpuidle_unregister_device(dev); + } + + free_percpu(calxeda_idle_cpuidle_devices); +} + +static struct cpuidle_driver calxeda_idle_driver = { + .name = "calxeda_idle", + .en_core_tk_irqen = 1, + .states = { + ARM_CPUIDLE_WFI_STATE, + { + .name = "PG", + .desc = "Power Gate", + .flags = CPUIDLE_FLAG_TIME_VALID, + .exit_latency = 30, + .power_usage = 50, + .target_residency = 200, + .enter = calxeda_pwrdown_idle, + }, + }, + .state_count = 2, +}; + +static int __init calxeda_cpuidle_init(void) +{ + int cpu_id; + int ret; + struct cpuidle_device *dev; + struct cpuidle_driver *drv = &calxeda_idle_driver; + + if (!of_machine_is_compatible("calxeda,highbank")) + return -ENODEV; + + ret = cpuidle_register_driver(drv); + if (ret) + return ret; + + calxeda_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device); + if (calxeda_idle_cpuidle_devices == NULL) { + ret = -ENOMEM; + goto unregister_drv; + } + + /* initialize state data for each cpuidle_device */ + for_each_possible_cpu(cpu_id) { + dev = per_cpu_ptr(calxeda_idle_cpuidle_devices, cpu_id); + dev->cpu = cpu_id; + dev->state_count = drv->state_count; + + ret = cpuidle_register_device(dev); + if (ret) { + pr_err("Failed to register cpu %u, error: %d\n", + cpu_id, ret); + goto uninit; + } + } + + return 0; + +uninit: + calxeda_idle_cpuidle_devices_uninit(); +unregister_drv: + cpuidle_unregister_driver(drv); + return ret; +} +module_init(calxeda_cpuidle_init); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/