1 /* 2 * i.MX27 Power Management Routines 3 * 4 * Based on Freescale's BSP 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/suspend.h> 12 #include <linux/io.h> 13 14 #include "hardware.h" 15 16 static int mx27_suspend_enter(suspend_state_t state) 17 { 18 u32 cscr; 19 switch (state) { 20 case PM_SUSPEND_MEM: 21 /* Clear MPEN and SPEN to disable MPLL/SPLL */ 22 cscr = __raw_readl(MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR)); 23 cscr &= 0xFFFFFFFC; 24 __raw_writel(cscr, MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR)); 25 /* Executes WFI */ 26 cpu_do_idle(); 27 break; 28 29 default: 30 return -EINVAL; 31 } 32 return 0; 33 } 34 35 static const struct platform_suspend_ops mx27_suspend_ops = { 36 .enter = mx27_suspend_enter, 37 .valid = suspend_valid_only_mem, 38 }; 39 40 static int __init mx27_pm_init(void) 41 { 42 if (!cpu_is_mx27()) 43 return 0; 44 45 suspend_set_ops(&mx27_suspend_ops); 46 return 0; 47 } 48 49 device_initcall(mx27_pm_init); 50