19cfc94ebSAndrew Lunn /* 29cfc94ebSAndrew Lunn * CPU idle Marvell Kirkwood SoCs 39cfc94ebSAndrew Lunn * 49cfc94ebSAndrew Lunn * This file is licensed under the terms of the GNU General Public 59cfc94ebSAndrew Lunn * License version 2. This program is licensed "as is" without any 69cfc94ebSAndrew Lunn * warranty of any kind, whether express or implied. 79cfc94ebSAndrew Lunn * 89cfc94ebSAndrew Lunn * The cpu idle uses wait-for-interrupt and DDR self refresh in order 99cfc94ebSAndrew Lunn * to implement two idle states - 109cfc94ebSAndrew Lunn * #1 wait-for-interrupt 119cfc94ebSAndrew Lunn * #2 wait-for-interrupt and DDR self refresh 12a8e39c35SDaniel Lezcano * 13a8e39c35SDaniel Lezcano * Maintainer: Jason Cooper <jason@lakedaemon.net> 14a8e39c35SDaniel Lezcano * Maintainer: Andrew Lunn <andrew@lunn.ch> 159cfc94ebSAndrew Lunn */ 169cfc94ebSAndrew Lunn 179cfc94ebSAndrew Lunn #include <linux/kernel.h> 189cfc94ebSAndrew Lunn #include <linux/module.h> 199cfc94ebSAndrew Lunn #include <linux/init.h> 209cfc94ebSAndrew Lunn #include <linux/platform_device.h> 219cfc94ebSAndrew Lunn #include <linux/cpuidle.h> 229cfc94ebSAndrew Lunn #include <linux/io.h> 239cfc94ebSAndrew Lunn #include <linux/export.h> 249cfc94ebSAndrew Lunn #include <asm/cpuidle.h> 259cfc94ebSAndrew Lunn 269cfc94ebSAndrew Lunn #define KIRKWOOD_MAX_STATES 2 279cfc94ebSAndrew Lunn 289cfc94ebSAndrew Lunn static void __iomem *ddr_operation_base; 299cfc94ebSAndrew Lunn 309cfc94ebSAndrew Lunn /* Actual code that puts the SoC in different idle states */ 319cfc94ebSAndrew Lunn static int kirkwood_enter_idle(struct cpuidle_device *dev, 329cfc94ebSAndrew Lunn struct cpuidle_driver *drv, 339cfc94ebSAndrew Lunn int index) 349cfc94ebSAndrew Lunn { 359cfc94ebSAndrew Lunn writel(0x7, ddr_operation_base); 369cfc94ebSAndrew Lunn cpu_do_idle(); 379cfc94ebSAndrew Lunn 389cfc94ebSAndrew Lunn return index; 399cfc94ebSAndrew Lunn } 409cfc94ebSAndrew Lunn 419cfc94ebSAndrew Lunn static struct cpuidle_driver kirkwood_idle_driver = { 429cfc94ebSAndrew Lunn .name = "kirkwood_idle", 439cfc94ebSAndrew Lunn .owner = THIS_MODULE, 449cfc94ebSAndrew Lunn .states[0] = ARM_CPUIDLE_WFI_STATE, 459cfc94ebSAndrew Lunn .states[1] = { 469cfc94ebSAndrew Lunn .enter = kirkwood_enter_idle, 479cfc94ebSAndrew Lunn .exit_latency = 10, 489cfc94ebSAndrew Lunn .target_residency = 100000, 499cfc94ebSAndrew Lunn .name = "DDR SR", 509cfc94ebSAndrew Lunn .desc = "WFI and DDR Self Refresh", 519cfc94ebSAndrew Lunn }, 529cfc94ebSAndrew Lunn .state_count = KIRKWOOD_MAX_STATES, 539cfc94ebSAndrew Lunn }; 549cfc94ebSAndrew Lunn 559cfc94ebSAndrew Lunn /* Initialize CPU idle by registering the idle states */ 569cfc94ebSAndrew Lunn static int kirkwood_cpuidle_probe(struct platform_device *pdev) 579cfc94ebSAndrew Lunn { 5885c3ebd4SYangtao Li ddr_operation_base = devm_platform_ioremap_resource(pdev, 0); 59488540bfSSilviu-Mihai Popescu if (IS_ERR(ddr_operation_base)) 60488540bfSSilviu-Mihai Popescu return PTR_ERR(ddr_operation_base); 619cfc94ebSAndrew Lunn 6230dc72c6SDaniel Lezcano return cpuidle_register(&kirkwood_idle_driver, NULL); 639cfc94ebSAndrew Lunn } 649cfc94ebSAndrew Lunn 6575d6137dSJingoo Han static int kirkwood_cpuidle_remove(struct platform_device *pdev) 669cfc94ebSAndrew Lunn { 6730dc72c6SDaniel Lezcano cpuidle_unregister(&kirkwood_idle_driver); 689cfc94ebSAndrew Lunn return 0; 699cfc94ebSAndrew Lunn } 709cfc94ebSAndrew Lunn 719cfc94ebSAndrew Lunn static struct platform_driver kirkwood_cpuidle_driver = { 729cfc94ebSAndrew Lunn .probe = kirkwood_cpuidle_probe, 739cfc94ebSAndrew Lunn .remove = kirkwood_cpuidle_remove, 749cfc94ebSAndrew Lunn .driver = { 759cfc94ebSAndrew Lunn .name = "kirkwood_cpuidle", 769cfc94ebSAndrew Lunn }, 779cfc94ebSAndrew Lunn }; 789cfc94ebSAndrew Lunn 799cfc94ebSAndrew Lunn module_platform_driver(kirkwood_cpuidle_driver); 809cfc94ebSAndrew Lunn 819cfc94ebSAndrew Lunn MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); 829cfc94ebSAndrew Lunn MODULE_DESCRIPTION("Kirkwood cpu idle driver"); 839cfc94ebSAndrew Lunn MODULE_LICENSE("GPL v2"); 849cfc94ebSAndrew Lunn MODULE_ALIAS("platform:kirkwood-cpuidle"); 85