ARM: kirkwood: Add standby support
Implements standby support for Kirkwood SoC. When the SoC enters
standby state the memory PM units are disabled, the DDR is set
in self-refresh mode, and the CPU is set in WFI.
At this point there's no clock gating, as that is considered each
driver's task.
Signed-off-by: Simon Guinot <sguinot@lacie.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/arch/arm/mach-kirkwood/Makefile b/arch/arm/mach-kirkwood/Makefile
index d1f8e3d..144b511 100644
--- a/arch/arm/mach-kirkwood/Makefile
+++ b/arch/arm/mach-kirkwood/Makefile
@@ -1,5 +1,7 @@
obj-y += common.o pcie.o
obj-$(CONFIG_KIRKWOOD_LEGACY) += irq.o mpp.o
+obj-$(CONFIG_PM) += pm.o
+
obj-$(CONFIG_MACH_D2NET_V2) += d2net_v2-setup.o lacie_v2-common.o
obj-$(CONFIG_MACH_NET2BIG_V2) += netxbig_v2-setup.o lacie_v2-common.o
obj-$(CONFIG_MACH_NET5BIG_V2) += netxbig_v2-setup.o lacie_v2-common.o
diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c
index 82d3ad8..cdde73a 100644
--- a/arch/arm/mach-kirkwood/board-dt.c
+++ b/arch/arm/mach-kirkwood/board-dt.c
@@ -101,6 +101,7 @@
/* Setup clocks for legacy devices */
kirkwood_legacy_clk_init();
+ kirkwood_pm_init();
kirkwood_cpuidle_init();
#ifdef CONFIG_KEXEC
diff --git a/arch/arm/mach-kirkwood/common.c b/arch/arm/mach-kirkwood/common.c
index 1767611..f3407a5 100644
--- a/arch/arm/mach-kirkwood/common.c
+++ b/arch/arm/mach-kirkwood/common.c
@@ -721,6 +721,7 @@
kirkwood_xor1_init();
kirkwood_crypto_init();
+ kirkwood_pm_init();
kirkwood_cpuidle_init();
#ifdef CONFIG_KEXEC
kexec_reinit = kirkwood_enable_pcie;
diff --git a/arch/arm/mach-kirkwood/common.h b/arch/arm/mach-kirkwood/common.h
index 1296de9..05fd648 100644
--- a/arch/arm/mach-kirkwood/common.h
+++ b/arch/arm/mach-kirkwood/common.h
@@ -58,6 +58,12 @@
void kirkwood_restart(enum reboot_mode, const char *);
void kirkwood_clk_init(void);
+#ifdef CONFIG_PM
+void kirkwood_pm_init(void);
+#else
+static inline void kirkwood_pm_init(void) {};
+#endif
+
/* board init functions for boards not fully converted to fdt */
#ifdef CONFIG_MACH_MV88F6281GTW_GE_DT
void mv88f6281gtw_ge_init(void);
diff --git a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
index 91242c9..8b9d1c9 100644
--- a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
+++ b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h
@@ -78,4 +78,6 @@
#define CGC_TDM (1 << 20)
#define CGC_RESERVED (0x6 << 21)
+#define MEMORY_PM_CTRL (BRIDGE_VIRT_BASE + 0x118)
+
#endif
diff --git a/arch/arm/mach-kirkwood/pm.c b/arch/arm/mach-kirkwood/pm.c
new file mode 100644
index 0000000..8783a71
--- /dev/null
+++ b/arch/arm/mach-kirkwood/pm.c
@@ -0,0 +1,73 @@
+/*
+ * Power Management driver for Marvell Kirkwood SoCs
+ *
+ * Copyright (C) 2013 Ezequiel Garcia <ezequiel@free-electrons.com>
+ * Copyright (C) 2010 Simon Guinot <sguinot@lacie.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License,
+ * version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/suspend.h>
+#include <linux/io.h>
+#include <mach/bridge-regs.h>
+
+static void __iomem *ddr_operation_base;
+
+static void kirkwood_low_power(void)
+{
+ u32 mem_pm_ctrl;
+
+ mem_pm_ctrl = readl(MEMORY_PM_CTRL);
+
+ /* Set peripherals to low-power mode */
+ writel_relaxed(~0, MEMORY_PM_CTRL);
+
+ /* Set DDR in self-refresh */
+ writel_relaxed(0x7, ddr_operation_base);
+
+ /*
+ * Set CPU in wait-for-interrupt state.
+ * This disables the CPU core clocks,
+ * the array clocks, and also the L2 controller.
+ */
+ cpu_do_idle();
+
+ writel_relaxed(mem_pm_ctrl, MEMORY_PM_CTRL);
+}
+
+static int kirkwood_suspend_enter(suspend_state_t state)
+{
+ switch (state) {
+ case PM_SUSPEND_STANDBY:
+ kirkwood_low_power();
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int kirkwood_pm_valid_standby(suspend_state_t state)
+{
+ return state == PM_SUSPEND_STANDBY;
+}
+
+static const struct platform_suspend_ops kirkwood_suspend_ops = {
+ .enter = kirkwood_suspend_enter,
+ .valid = kirkwood_pm_valid_standby,
+};
+
+int __init kirkwood_pm_init(void)
+{
+ ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4);
+ suspend_set_ops(&kirkwood_suspend_ops);
+ return 0;
+}