arch/sh/kernel/cpu/shmobile/pm.c

   1 /*
   2  * arch/sh/kernel/cpu/shmobile/pm.c
   3  *
   4  * Power management support code for SuperH Mobile
   5  *
   6  *  Copyright (C) 2009 Magnus Damm
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/io.h>
  15 #include <linux/suspend.h>
  16 #include <asm/suspend.h>
  17 #include <asm/uaccess.h>
  18
  19 /*
  20  * Sleep modes available on SuperH Mobile:
  21  *
  22  * Sleep mode is just plain "sleep" instruction
  23  * Sleep Self-Refresh mode is above plus RAM put in Self-Refresh
  24  * Standby Self-Refresh mode is above plus stopped clocks
  25  */
  26 #define SUSP_MODE_SLEEP         (SUSP_SH_SLEEP)
  27 #define SUSP_MODE_SLEEP_SF      (SUSP_SH_SLEEP | SUSP_SH_SF)
  28 #define SUSP_MODE_STANDBY_SF    (SUSP_SH_STANDBY | SUSP_SH_SF)
  29
  30 /*
  31  * The following modes are not there yet:
  32  *
  33  * R-standby mode is unsupported, but will be added in the future
  34  * U-standby mode is low priority since it needs bootloader hacks
  35  */
  36
  37 #define ILRAM_BASE 0xe5200000
  38
  39 extern const unsigned char sh_mobile_standby[];
  40 extern const unsigned int sh_mobile_standby_size;
  41
  42 void sh_mobile_call_standby(unsigned long mode)
  43 {
  44         void *onchip_mem = (void *)ILRAM_BASE;
  45         void (*standby_onchip_mem)(unsigned long, unsigned long) = onchip_mem;
  46
  47         /* Let assembly snippet in on-chip memory handle the rest */
  48         standby_onchip_mem(mode, ILRAM_BASE);
  49 }
  50
  51 static int sh_pm_enter(suspend_state_t state)
  52 {
  53         local_irq_disable();
  54         set_bl_bit();
  55         sh_mobile_call_standby(SUSP_MODE_STANDBY_SF);
  56         local_irq_disable();
  57         clear_bl_bit();
  58         return 0;
  59 }
  60
  61 static struct platform_suspend_ops sh_pm_ops = {
  62         .enter          = sh_pm_enter,
  63         .valid          = suspend_valid_only_mem,
  64 };
  65
  66 static int __init sh_pm_init(void)
  67 {
  68         void *onchip_mem = (void *)ILRAM_BASE;
  69
  70         /* Copy the assembly snippet to the otherwise ununsed ILRAM */
  71         memcpy(onchip_mem, sh_mobile_standby, sh_mobile_standby_size);
  72         wmb();
  73         ctrl_barrier();
  74
  75         suspend_set_ops(&sh_pm_ops);
  76         sh_mobile_setup_cpuidle();
  77         return 0;
  78 }
  79
  80 late_initcall(sh_pm_init);