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/of_address.h> 11 #include <linux/kernel.h> 12 #include <linux/suspend.h> 13 #include <linux/io.h> 14 15 #include "hardware.h" 16 17 static int mx27_suspend_enter(suspend_state_t state) 18 { 19 void __iomem *ccm_base; 20 struct device_node *np; 21 u32 cscr; 22 23 np = of_find_compatible_node(NULL, NULL, "fsl,imx27-ccm"); 24 ccm_base = of_iomap(np, 0); 25 BUG_ON(!ccm_base); 26 27 switch (state) { 28 case PM_SUSPEND_MEM: 29 /* Clear MPEN and SPEN to disable MPLL/SPLL */ 30 cscr = imx_readl(ccm_base); 31 cscr &= 0xFFFFFFFC; 32 imx_writel(cscr, ccm_base); 33 /* Executes WFI */ 34 cpu_do_idle(); 35 break; 36 37 default: 38 return -EINVAL; 39 } 40 return 0; 41 } 42 43 static const struct platform_suspend_ops mx27_suspend_ops = { 44 .enter = mx27_suspend_enter, 45 .valid = suspend_valid_only_mem, 46 }; 47 48 void __init imx27_pm_init(void) 49 { 50 suspend_set_ops(&mx27_suspend_ops); 51 } 52