1*9cfc94ebSAndrew Lunn /* 2*9cfc94ebSAndrew Lunn * arch/arm/mach-kirkwood/cpuidle.c 3*9cfc94ebSAndrew Lunn * 4*9cfc94ebSAndrew Lunn * CPU idle Marvell Kirkwood SoCs 5*9cfc94ebSAndrew Lunn * 6*9cfc94ebSAndrew Lunn * This file is licensed under the terms of the GNU General Public 7*9cfc94ebSAndrew Lunn * License version 2. This program is licensed "as is" without any 8*9cfc94ebSAndrew Lunn * warranty of any kind, whether express or implied. 9*9cfc94ebSAndrew Lunn * 10*9cfc94ebSAndrew Lunn * The cpu idle uses wait-for-interrupt and DDR self refresh in order 11*9cfc94ebSAndrew Lunn * to implement two idle states - 12*9cfc94ebSAndrew Lunn * #1 wait-for-interrupt 13*9cfc94ebSAndrew Lunn * #2 wait-for-interrupt and DDR self refresh 14*9cfc94ebSAndrew Lunn */ 15*9cfc94ebSAndrew Lunn 16*9cfc94ebSAndrew Lunn #include <linux/kernel.h> 17*9cfc94ebSAndrew Lunn #include <linux/module.h> 18*9cfc94ebSAndrew Lunn #include <linux/init.h> 19*9cfc94ebSAndrew Lunn #include <linux/platform_device.h> 20*9cfc94ebSAndrew Lunn #include <linux/cpuidle.h> 21*9cfc94ebSAndrew Lunn #include <linux/io.h> 22*9cfc94ebSAndrew Lunn #include <linux/export.h> 23*9cfc94ebSAndrew Lunn #include <asm/proc-fns.h> 24*9cfc94ebSAndrew Lunn #include <asm/cpuidle.h> 25*9cfc94ebSAndrew Lunn 26*9cfc94ebSAndrew Lunn #define KIRKWOOD_MAX_STATES 2 27*9cfc94ebSAndrew Lunn 28*9cfc94ebSAndrew Lunn static void __iomem *ddr_operation_base; 29*9cfc94ebSAndrew Lunn 30*9cfc94ebSAndrew Lunn /* Actual code that puts the SoC in different idle states */ 31*9cfc94ebSAndrew Lunn static int kirkwood_enter_idle(struct cpuidle_device *dev, 32*9cfc94ebSAndrew Lunn struct cpuidle_driver *drv, 33*9cfc94ebSAndrew Lunn int index) 34*9cfc94ebSAndrew Lunn { 35*9cfc94ebSAndrew Lunn writel(0x7, ddr_operation_base); 36*9cfc94ebSAndrew Lunn cpu_do_idle(); 37*9cfc94ebSAndrew Lunn 38*9cfc94ebSAndrew Lunn return index; 39*9cfc94ebSAndrew Lunn } 40*9cfc94ebSAndrew Lunn 41*9cfc94ebSAndrew Lunn static struct cpuidle_driver kirkwood_idle_driver = { 42*9cfc94ebSAndrew Lunn .name = "kirkwood_idle", 43*9cfc94ebSAndrew Lunn .owner = THIS_MODULE, 44*9cfc94ebSAndrew Lunn .en_core_tk_irqen = 1, 45*9cfc94ebSAndrew Lunn .states[0] = ARM_CPUIDLE_WFI_STATE, 46*9cfc94ebSAndrew Lunn .states[1] = { 47*9cfc94ebSAndrew Lunn .enter = kirkwood_enter_idle, 48*9cfc94ebSAndrew Lunn .exit_latency = 10, 49*9cfc94ebSAndrew Lunn .target_residency = 100000, 50*9cfc94ebSAndrew Lunn .flags = CPUIDLE_FLAG_TIME_VALID, 51*9cfc94ebSAndrew Lunn .name = "DDR SR", 52*9cfc94ebSAndrew Lunn .desc = "WFI and DDR Self Refresh", 53*9cfc94ebSAndrew Lunn }, 54*9cfc94ebSAndrew Lunn .state_count = KIRKWOOD_MAX_STATES, 55*9cfc94ebSAndrew Lunn }; 56*9cfc94ebSAndrew Lunn static struct cpuidle_device *device; 57*9cfc94ebSAndrew Lunn 58*9cfc94ebSAndrew Lunn static DEFINE_PER_CPU(struct cpuidle_device, kirkwood_cpuidle_device); 59*9cfc94ebSAndrew Lunn 60*9cfc94ebSAndrew Lunn /* Initialize CPU idle by registering the idle states */ 61*9cfc94ebSAndrew Lunn static int kirkwood_cpuidle_probe(struct platform_device *pdev) 62*9cfc94ebSAndrew Lunn { 63*9cfc94ebSAndrew Lunn struct resource *res; 64*9cfc94ebSAndrew Lunn 65*9cfc94ebSAndrew Lunn res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 66*9cfc94ebSAndrew Lunn if (res == NULL) 67*9cfc94ebSAndrew Lunn return -EINVAL; 68*9cfc94ebSAndrew Lunn 69*9cfc94ebSAndrew Lunn ddr_operation_base = devm_request_and_ioremap(&pdev->dev, res); 70*9cfc94ebSAndrew Lunn if (!ddr_operation_base) 71*9cfc94ebSAndrew Lunn return -EADDRNOTAVAIL; 72*9cfc94ebSAndrew Lunn 73*9cfc94ebSAndrew Lunn device = &per_cpu(kirkwood_cpuidle_device, smp_processor_id()); 74*9cfc94ebSAndrew Lunn device->state_count = KIRKWOOD_MAX_STATES; 75*9cfc94ebSAndrew Lunn 76*9cfc94ebSAndrew Lunn cpuidle_register_driver(&kirkwood_idle_driver); 77*9cfc94ebSAndrew Lunn if (cpuidle_register_device(device)) { 78*9cfc94ebSAndrew Lunn pr_err("kirkwood_init_cpuidle: Failed registering\n"); 79*9cfc94ebSAndrew Lunn return -EIO; 80*9cfc94ebSAndrew Lunn } 81*9cfc94ebSAndrew Lunn return 0; 82*9cfc94ebSAndrew Lunn } 83*9cfc94ebSAndrew Lunn 84*9cfc94ebSAndrew Lunn int kirkwood_cpuidle_remove(struct platform_device *pdev) 85*9cfc94ebSAndrew Lunn { 86*9cfc94ebSAndrew Lunn cpuidle_unregister_device(device); 87*9cfc94ebSAndrew Lunn cpuidle_unregister_driver(&kirkwood_idle_driver); 88*9cfc94ebSAndrew Lunn 89*9cfc94ebSAndrew Lunn return 0; 90*9cfc94ebSAndrew Lunn } 91*9cfc94ebSAndrew Lunn 92*9cfc94ebSAndrew Lunn static struct platform_driver kirkwood_cpuidle_driver = { 93*9cfc94ebSAndrew Lunn .probe = kirkwood_cpuidle_probe, 94*9cfc94ebSAndrew Lunn .remove = kirkwood_cpuidle_remove, 95*9cfc94ebSAndrew Lunn .driver = { 96*9cfc94ebSAndrew Lunn .name = "kirkwood_cpuidle", 97*9cfc94ebSAndrew Lunn .owner = THIS_MODULE, 98*9cfc94ebSAndrew Lunn }, 99*9cfc94ebSAndrew Lunn }; 100*9cfc94ebSAndrew Lunn 101*9cfc94ebSAndrew Lunn module_platform_driver(kirkwood_cpuidle_driver); 102*9cfc94ebSAndrew Lunn 103*9cfc94ebSAndrew Lunn MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); 104*9cfc94ebSAndrew Lunn MODULE_DESCRIPTION("Kirkwood cpu idle driver"); 105*9cfc94ebSAndrew Lunn MODULE_LICENSE("GPL v2"); 106*9cfc94ebSAndrew Lunn MODULE_ALIAS("platform:kirkwood-cpuidle"); 107