/* * CPU idle Marvell Kirkwood SoCs * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. * * The cpu idle uses wait-for-interrupt and DDR self refresh in order * to implement two idle states - * #1 wait-for-interrupt * #2 wait-for-interrupt and DDR self refresh * * Maintainer: Jason Cooper <jason@lakedaemon.net> * Maintainer: Andrew Lunn <andrew@lunn.ch> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/cpuidle.h> #include <linux/io.h> #include <linux/export.h> #include <asm/cpuidle.h> #define KIRKWOOD_MAX_STATES 2 static void __iomem *ddr_operation_base; /* Actual code that puts the SoC in different idle states */ static int kirkwood_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { writel(0x7, ddr_operation_base); cpu_do_idle(); return index; } static struct cpuidle_driver kirkwood_idle_driver = { .name = "kirkwood_idle", .owner = THIS_MODULE, .states[0] = ARM_CPUIDLE_WFI_STATE, .states[1] = { .enter = kirkwood_enter_idle, .exit_latency = 10, .target_residency = 100000, .name = "DDR SR", .desc = "WFI and DDR Self Refresh", }, .state_count = KIRKWOOD_MAX_STATES, }; /* Initialize CPU idle by registering the idle states */ static int kirkwood_cpuidle_probe(struct platform_device *pdev) { struct resource *res; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); ddr_operation_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(ddr_operation_base)) return PTR_ERR(ddr_operation_base); return cpuidle_register(&kirkwood_idle_driver, NULL); } static int kirkwood_cpuidle_remove(struct platform_device *pdev) { cpuidle_unregister(&kirkwood_idle_driver); return 0; } static struct platform_driver kirkwood_cpuidle_driver = { .probe = kirkwood_cpuidle_probe, .remove = kirkwood_cpuidle_remove, .driver = { .name = "kirkwood_cpuidle", }, }; module_platform_driver(kirkwood_cpuidle_driver); MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); MODULE_DESCRIPTION("Kirkwood cpu idle driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:kirkwood-cpuidle");