From 1ea60cf7062271f0d53d09268726aa1544bf4836 Mon Sep 17 00:00:00 2001 From: Albin Tonnerre Date: Sun, 1 Nov 2009 18:40:50 +0100 Subject: ARM: 5778/1: AT91: Add cpuidle support This patch adds the support for cpuidle on AT91 SoCs, taken from the cpuidle support in mach-kirkwood. cpuidle needs sdram_selfrefresh_enable and _disable, so move their definition to a separate header file instead of duplicating the code already used in pm.c. Tested-by: Nicolas Ferre Signed-off-by: Albin Tonnerre Acked-by: Andrew Victor Signed-off-by: Russell King --- arch/arm/mach-at91/pm.h | 67 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 arch/arm/mach-at91/pm.h (limited to 'arch/arm/mach-at91/pm.h') diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h new file mode 100644 index 000000000000..08322c44df1a --- /dev/null +++ b/arch/arm/mach-at91/pm.h @@ -0,0 +1,67 @@ +#ifdef CONFIG_ARCH_AT91RM9200 +#include + +/* + * The AT91RM9200 goes into self-refresh mode with this command, and will + * terminate self-refresh automatically on the next SDRAM access. + * + * Self-refresh mode is exited as soon as a memory access is made, but we don't + * know for sure when that happens. However, we need to restore the low-power + * mode if it was enabled before going idle. Restoring low-power mode while + * still in self-refresh is "not recommended", but seems to work. + */ + +static inline u32 sdram_selfrefresh_enable(void) +{ + u32 saved_lpr = at91_sys_read(AT91_SDRAMC_LPR); + + at91_sys_write(AT91_SDRAMC_LPR, 0); + at91_sys_write(AT91_SDRAMC_SRR, 1); + return saved_lpr; +} + +#define sdram_selfrefresh_disable(saved_lpr) at91_sys_write(AT91_SDRAMC_LPR, saved_lpr) + +#elif defined(CONFIG_ARCH_AT91CAP9) +#include + + +static inline u32 sdram_selfrefresh_enable(void) +{ + u32 saved_lpr, lpr; + + saved_lpr = at91_sys_read(AT91_DDRSDRC_LPR); + + lpr = saved_lpr & ~AT91_DDRSDRC_LPCB; + at91_sys_write(AT91_DDRSDRC_LPR, lpr | AT91_DDRSDRC_LPCB_SELF_REFRESH); + return saved_lpr; +} + +#define sdram_selfrefresh_disable(saved_lpr) at91_sys_write(AT91_DDRSDRC_LPR, saved_lpr) + +#else +#include + +#ifdef CONFIG_ARCH_AT91SAM9263 +/* + * FIXME either or both the SDRAM controllers (EB0, EB1) might be in use; + * handle those cases both here and in the Suspend-To-RAM support. + */ +#define AT91_SDRAMC AT91_SDRAMC0 +#warning Assuming EB1 SDRAM controller is *NOT* used +#endif + +static inline u32 sdram_selfrefresh_enable(void) +{ + u32 saved_lpr, lpr; + + saved_lpr = at91_sys_read(AT91_SDRAMC_LPR); + + lpr = saved_lpr & ~AT91_SDRAMC_LPCB; + at91_sys_write(AT91_SDRAMC_LPR, lpr | AT91_SDRAMC_LPCB_SELF_REFRESH); + return saved_lpr; +} + +#define sdram_selfrefresh_disable(saved_lpr) at91_sys_write(AT91_SDRAMC_LPR, saved_lpr) + +#endif -- cgit v1.2.3