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Diffstat (limited to 'arch/sh/kernel/cpu/shmobile/pm.c')
-rw-r--r-- | arch/sh/kernel/cpu/shmobile/pm.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/shmobile/pm.c b/arch/sh/kernel/cpu/shmobile/pm.c new file mode 100644 index 000000000000..8c067adf6830 --- /dev/null +++ b/arch/sh/kernel/cpu/shmobile/pm.c @@ -0,0 +1,92 @@ +/* + * arch/sh/kernel/cpu/sh4a/pm-sh_mobile.c + * + * Power management support code for SuperH Mobile + * + * Copyright (C) 2009 Magnus Damm + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/suspend.h> +#include <asm/suspend.h> +#include <asm/uaccess.h> + +/* + * Sleep modes available on SuperH Mobile: + * + * Sleep mode is just plain "sleep" instruction + * Sleep Self-Refresh mode is above plus RAM put in Self-Refresh + * Standby Self-Refresh mode is above plus stopped clocks + */ +#define SUSP_MODE_SLEEP (SUSP_SH_SLEEP) +#define SUSP_MODE_SLEEP_SF (SUSP_SH_SLEEP | SUSP_SH_SF) +#define SUSP_MODE_STANDBY_SF (SUSP_SH_STANDBY | SUSP_SH_SF) + +/* + * The following modes are not there yet: + * + * R-standby mode is unsupported, but will be added in the future + * U-standby mode is low priority since it needs bootloader hacks + * + * All modes should be tied in with cpuidle. But before that can + * happen we need to keep track of enabled hardware blocks so we + * can avoid entering sleep modes that stop clocks to hardware + * blocks that are in use even though the cpu core is idle. + */ + +extern const unsigned char sh_mobile_standby[]; +extern const unsigned int sh_mobile_standby_size; + +static void sh_mobile_call_standby(unsigned long mode) +{ + extern void *vbr_base; + void *onchip_mem = (void *)0xe5200000; /* ILRAM */ + void (*standby_onchip_mem)(unsigned long) = onchip_mem; + + /* Note: Wake up from sleep may generate exceptions! + * Setup VBR to point to on-chip ram if self-refresh is + * going to be used. + */ + if (mode & SUSP_SH_SF) + asm volatile("ldc %0, vbr" : : "r" (onchip_mem) : "memory"); + + /* Copy the assembly snippet to the otherwise ununsed ILRAM */ + memcpy(onchip_mem, sh_mobile_standby, sh_mobile_standby_size); + wmb(); + ctrl_barrier(); + + /* Let assembly snippet in on-chip memory handle the rest */ + standby_onchip_mem(mode); + + /* Put VBR back in System RAM again */ + if (mode & SUSP_SH_SF) + asm volatile("ldc %0, vbr" : : "r" (&vbr_base) : "memory"); +} + +static int sh_pm_enter(suspend_state_t state) +{ + local_irq_disable(); + set_bl_bit(); + sh_mobile_call_standby(SUSP_MODE_STANDBY_SF); + local_irq_disable(); + clear_bl_bit(); + return 0; +} + +static struct platform_suspend_ops sh_pm_ops = { + .enter = sh_pm_enter, + .valid = suspend_valid_only_mem, +}; + +static int __init sh_pm_init(void) +{ + suspend_set_ops(&sh_pm_ops); + return 0; +} + +late_initcall(sh_pm_init); |