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author | Arnd Bergmann <arnd@arndb.de> | 2015-04-14 01:50:21 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2015-04-14 01:50:21 +0200 |
commit | 89522f0f8bd5056dec21bb7de073cbd5886e435c (patch) | |
tree | f4755458dbff71851af23675417173a95271491f /arch/arm/mach-at91/pm.c | |
parent | e8621d83c10ee95798bdb5e04f54439a7c1c9a2b (diff) | |
parent | 2e57dc087c27b8b0bd4a9e5f2c6f28f3cd0b47ff (diff) |
Merge tag 'at91-cleanup4_bis' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91 into next/multiplatform
Pull "Fourth batch of cleanup for 4.1" from Nicolas Ferre:
- 1 issues revealed by the kbuild test robot fixed
- move of some functions and macros into relevant files to be able to
streamline the at91 specific header afterwards
* tag 'at91-cleanup4_bis' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91:
ARM: at91/pm: move AT91_MEMCTRL_* to pm.h
ARM: at91/pm: move the standby functions to pm.c
ARM: at91: fix pm_suspend.S compilation when ARMv6 is selected
Diffstat (limited to 'arch/arm/mach-at91/pm.c')
-rw-r--r-- | arch/arm/mach-at91/pm.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index f93a735ba327..5062699cbb12 100644 --- a/arch/arm/mach-at91/pm.c +++ b/arch/arm/mach-at91/pm.c @@ -222,6 +222,95 @@ static void at91_pm_set_standby(void (*at91_standby)(void)) at91_cpuidle_device.dev.platform_data = at91_standby; } +/* + * 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 void at91rm9200_standby(void) +{ + u32 lpr = at91_ramc_read(0, AT91RM9200_SDRAMC_LPR); + + asm volatile( + "b 1f\n\t" + ".align 5\n\t" + "1: mcr p15, 0, %0, c7, c10, 4\n\t" + " str %0, [%1, %2]\n\t" + " str %3, [%1, %4]\n\t" + " mcr p15, 0, %0, c7, c0, 4\n\t" + " str %5, [%1, %2]" + : + : "r" (0), "r" (at91_ramc_base[0]), "r" (AT91RM9200_SDRAMC_LPR), + "r" (1), "r" (AT91RM9200_SDRAMC_SRR), + "r" (lpr)); +} + +/* We manage both DDRAM/SDRAM controllers, we need more than one value to + * remember. + */ +static void at91_ddr_standby(void) +{ + /* Those two values allow us to delay self-refresh activation + * to the maximum. */ + u32 lpr0, lpr1 = 0; + u32 saved_lpr0, saved_lpr1 = 0; + + if (at91_ramc_base[1]) { + saved_lpr1 = at91_ramc_read(1, AT91_DDRSDRC_LPR); + lpr1 = saved_lpr1 & ~AT91_DDRSDRC_LPCB; + lpr1 |= AT91_DDRSDRC_LPCB_SELF_REFRESH; + } + + saved_lpr0 = at91_ramc_read(0, AT91_DDRSDRC_LPR); + lpr0 = saved_lpr0 & ~AT91_DDRSDRC_LPCB; + lpr0 |= AT91_DDRSDRC_LPCB_SELF_REFRESH; + + /* self-refresh mode now */ + at91_ramc_write(0, AT91_DDRSDRC_LPR, lpr0); + if (at91_ramc_base[1]) + at91_ramc_write(1, AT91_DDRSDRC_LPR, lpr1); + + cpu_do_idle(); + + at91_ramc_write(0, AT91_DDRSDRC_LPR, saved_lpr0); + if (at91_ramc_base[1]) + at91_ramc_write(1, AT91_DDRSDRC_LPR, saved_lpr1); +} + +/* We manage both DDRAM/SDRAM controllers, we need more than one value to + * remember. + */ +static void at91sam9_sdram_standby(void) +{ + u32 lpr0, lpr1 = 0; + u32 saved_lpr0, saved_lpr1 = 0; + + if (at91_ramc_base[1]) { + saved_lpr1 = at91_ramc_read(1, AT91_SDRAMC_LPR); + lpr1 = saved_lpr1 & ~AT91_SDRAMC_LPCB; + lpr1 |= AT91_SDRAMC_LPCB_SELF_REFRESH; + } + + saved_lpr0 = at91_ramc_read(0, AT91_SDRAMC_LPR); + lpr0 = saved_lpr0 & ~AT91_SDRAMC_LPCB; + lpr0 |= AT91_SDRAMC_LPCB_SELF_REFRESH; + + /* self-refresh mode now */ + at91_ramc_write(0, AT91_SDRAMC_LPR, lpr0); + if (at91_ramc_base[1]) + at91_ramc_write(1, AT91_SDRAMC_LPR, lpr1); + + cpu_do_idle(); + + at91_ramc_write(0, AT91_SDRAMC_LPR, saved_lpr0); + if (at91_ramc_base[1]) + at91_ramc_write(1, AT91_SDRAMC_LPR, saved_lpr1); +} + static const struct of_device_id ramc_ids[] __initconst = { { .compatible = "atmel,at91rm9200-sdramc", .data = at91rm9200_standby }, { .compatible = "atmel,at91sam9260-sdramc", .data = at91sam9_sdram_standby }, |