avr32: Power Management support ("standby" and "mem" modes)

Implement Standby support. In this mode, we'll suspend all drivers,
put the SDRAM in self-refresh mode and switch off the HSB bus
("frozen" mode.)

Implement Suspend-to-mem support. In this mode, we suspend all
drivers, put the SDRAM into self-refresh mode and switch off all
internal clocks except the 32 kHz oscillator ("stop" mode.)

The lowest-level suspend code runs from a small portion of SRAM
allocated at startup time. This gets rid of a small potential race
with the SDRAM where we might try to enter self-refresh mode in the
middle of an icache burst. We also relocate all interrupt and
exception handlers to SRAM during the small window when we enter and
exit the low-power modes.

We don't need to do any special tricks to start and stop the PLL. The
main clock is automatically gated by hardware until the PLL is stable.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/arch/avr32/mach-at32ap/sdramc.h b/arch/avr32/mach-at32ap/sdramc.h
new file mode 100644
index 000000000000..66eeaed49073
--- /dev/null
+++ b/arch/avr32/mach-at32ap/sdramc.h
@@ -0,0 +1,76 @@
+/*
+ * Register definitions for the AT32AP SDRAM Controller
+ *
+ * Copyright (C) 2008 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+/* Register offsets */
+#define SDRAMC_MR			0x0000
+#define SDRAMC_TR			0x0004
+#define SDRAMC_CR			0x0008
+#define SDRAMC_HSR			0x000c
+#define SDRAMC_LPR			0x0010
+#define SDRAMC_IER			0x0014
+#define SDRAMC_IDR			0x0018
+#define SDRAMC_IMR			0x001c
+#define SDRAMC_ISR			0x0020
+#define SDRAMC_MDR			0x0024
+
+/* MR - Mode Register */
+#define SDRAMC_MR_MODE_NORMAL		(  0 <<  0)
+#define SDRAMC_MR_MODE_NOP		(  1 <<  0)
+#define SDRAMC_MR_MODE_BANKS_PRECHARGE	(  2 <<  0)
+#define SDRAMC_MR_MODE_LOAD_MODE	(  3 <<  0)
+#define SDRAMC_MR_MODE_AUTO_REFRESH	(  4 <<  0)
+#define SDRAMC_MR_MODE_EXT_LOAD_MODE	(  5 <<  0)
+#define SDRAMC_MR_MODE_POWER_DOWN	(  6 <<  0)
+
+/* CR - Configuration Register */
+#define SDRAMC_CR_NC_8_BITS		(  0 <<  0)
+#define SDRAMC_CR_NC_9_BITS		(  1 <<  0)
+#define SDRAMC_CR_NC_10_BITS		(  2 <<  0)
+#define SDRAMC_CR_NC_11_BITS		(  3 <<  0)
+#define SDRAMC_CR_NR_11_BITS		(  0 <<  2)
+#define SDRAMC_CR_NR_12_BITS		(  1 <<  2)
+#define SDRAMC_CR_NR_13_BITS		(  2 <<  2)
+#define SDRAMC_CR_NB_2_BANKS		(  0 <<  4)
+#define SDRAMC_CR_NB_4_BANKS		(  1 <<  4)
+#define SDRAMC_CR_CAS(x)		((x) <<  5)
+#define SDRAMC_CR_DBW_32_BITS		(  0 <<  7)
+#define SDRAMC_CR_DBW_16_BITS		(  1 <<  7)
+#define SDRAMC_CR_TWR(x)		((x) <<  8)
+#define SDRAMC_CR_TRC(x)		((x) << 12)
+#define SDRAMC_CR_TRP(x)		((x) << 16)
+#define SDRAMC_CR_TRCD(x)		((x) << 20)
+#define SDRAMC_CR_TRAS(x)		((x) << 24)
+#define SDRAMC_CR_TXSR(x)		((x) << 28)
+
+/* HSR - High Speed Register */
+#define SDRAMC_HSR_DA			(  1 <<  0)
+
+/* LPR - Low Power Register */
+#define SDRAMC_LPR_LPCB_INHIBIT		(  0 <<  0)
+#define SDRAMC_LPR_LPCB_SELF_RFR	(  1 <<  0)
+#define SDRAMC_LPR_LPCB_PDOWN		(  2 <<  0)
+#define SDRAMC_LPR_LPCB_DEEP_PDOWN	(  3 <<  0)
+#define SDRAMC_LPR_PASR(x)		((x) <<  4)
+#define SDRAMC_LPR_TCSR(x)		((x) <<  8)
+#define SDRAMC_LPR_DS(x)		((x) << 10)
+#define SDRAMC_LPR_TIMEOUT(x)		((x) << 12)
+
+/* IER/IDR/IMR/ISR - Interrupt Enable/Disable/Mask/Status Register */
+#define SDRAMC_ISR_RES			(  1 <<  0)
+
+/* MDR - Memory Device Register */
+#define SDRAMC_MDR_MD_SDRAM		(  0 <<  0)
+#define SDRAMC_MDR_MD_LOW_PWR_SDRAM	(  1 <<  0)
+
+/* Register access macros */
+#define sdramc_readl(reg) \
+	__raw_readl((void __iomem __force *)SDRAMC_BASE + SDRAMC_##reg)
+#define sdramc_writel(reg, value) \
+	__raw_writel(value, (void __iomem __force *)SDRAMC_BASE + SDRAMC_##reg)