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-rw-r--r--arch/arm/mach-at91/pm.h115
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h
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+++ b/arch/arm/mach-at91/pm.h
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+/*
+ * AT91 Power Management
+ *
+ * Copyright (C) 2005 David Brownell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#ifndef __ARCH_ARM_MACH_AT91_PM
+#define __ARCH_ARM_MACH_AT91_PM
+
+#include <asm/proc-fns.h>
+
+#include <mach/at91_ramc.h>
+#include <mach/at91rm9200_sdramc.h>
+
+#ifdef CONFIG_PM
+extern void at91_pm_set_standby(void (*at91_standby)(void));
+#else
+static inline void at91_pm_set_standby(void (*at91_standby)(void)) { }
+#endif
+
+/*
+ * 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 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_BASE_SYS), "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 inline 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 inline 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);
+}
+
+#endif