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 #include <mach/hardware.h> 14 15 static int mx27_suspend_enter(suspend_state_t state) 16 { 17 u32 cscr; 18 switch (state) { 19 case PM_SUSPEND_MEM: 20 /* Clear MPEN and SPEN to disable MPLL/SPLL */ 21 cscr = __raw_readl(MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR)); 22 cscr &= 0xFFFFFFFC; 23 __raw_writel(cscr, MX27_IO_ADDRESS(MX27_CCM_BASE_ADDR)); 24 /* Executes WFI */ 25 cpu_do_idle(); 26 break; 27 28 default: 29 return -EINVAL; 30 } 31 return 0; 32 } 33 34 static const struct platform_suspend_ops mx27_suspend_ops = { 35 .enter = mx27_suspend_enter, 36 .valid = suspend_valid_only_mem, 37 }; 38 39 static int __init mx27_pm_init(void) 40 { 41 if (!cpu_is_mx27()) 42 return 0; 43 44 suspend_set_ops(&mx27_suspend_ops); 45 return 0; 46 } 47 48 device_initcall(mx27_pm_init); 49