[PATCH 10/17] ARM: mvebu: implement suspend/resume support for Armada XP
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Fri Oct 24 04:59:23 PDT 2014
This commit implements the core of the platform code to enable
suspend/resume on Armada XP. It registers the platform_suspend_ops
structure, and implements the ->enter() hook of this structure.
It is worth mentioning that this commit only provides the SoC-level
part of suspend/resume, which calls into some board-specific code
provided in a follow-up commit.
The most important thing that this SoC-level code has to do is to
build an in-memory structure that contains a magic number, the return
address in the kernel after resume, and a set of address/value
pairs. This structure is used by the bootloader to restore a certain
number of registers (according to the set of address/value pairs) and
then jump back into the kernel at the provided location.
The code also puts the SDRAM into self-refresh mode, before calling
into board-specific code to actually enter the suspend to RAM state.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
arch/arm/mach-mvebu/Makefile | 2 +-
arch/arm/mach-mvebu/common.h | 2 +
arch/arm/mach-mvebu/pm.c | 220 +++++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-mvebu/pmsu.h | 1 +
4 files changed, 224 insertions(+), 1 deletion(-)
create mode 100644 arch/arm/mach-mvebu/pm.c
diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index e24136b..e2bd96f 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -7,7 +7,7 @@ CFLAGS_pmsu.o := -march=armv7-a
obj-$(CONFIG_MACH_MVEBU_ANY) += system-controller.o mvebu-soc-id.o
ifeq ($(CONFIG_MACH_MVEBU_V7),y)
-obj-y += cpu-reset.o board-v7.o coherency.o coherency_ll.o pmsu.o pmsu_ll.o
+obj-y += cpu-reset.o board-v7.o coherency.o coherency_ll.o pmsu.o pmsu_ll.o pm.o
obj-$(CONFIG_SMP) += platsmp.o headsmp.o platsmp-a9.o headsmp-a9.o
endif
diff --git a/arch/arm/mach-mvebu/common.h b/arch/arm/mach-mvebu/common.h
index 3ccb40c..3e0aca1 100644
--- a/arch/arm/mach-mvebu/common.h
+++ b/arch/arm/mach-mvebu/common.h
@@ -25,4 +25,6 @@ int mvebu_system_controller_get_soc_id(u32 *dev, u32 *rev);
void __iomem *mvebu_get_scu_base(void);
+int mvebu_pm_init(void (*board_pm_enter)(void __iomem *sdram_reg, u32 srcmd));
+
#endif
diff --git a/arch/arm/mach-mvebu/pm.c b/arch/arm/mach-mvebu/pm.c
new file mode 100644
index 0000000..19b6fb8
--- /dev/null
+++ b/arch/arm/mach-mvebu/pm.c
@@ -0,0 +1,220 @@
+/*
+ * Suspend/resume support. Currently supporting Armada XP only.
+ *
+ * Copyright (C) 2014 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/cpu_pm.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mbus.h>
+#include <linux/of_address.h>
+#include <linux/suspend.h>
+#include <asm/cacheflush.h>
+#include <asm/outercache.h>
+#include <asm/suspend.h>
+
+#include "coherency.h"
+#include "pmsu.h"
+
+#define SDRAM_CONFIG_OFFS 0x0
+#define SDRAM_CONFIG_SR_MODE_BIT BIT(24)
+#define SDRAM_OPERATION_OFFS 0x18
+#define SDRAM_OPERATION_SELF_REFRESH 0x7
+#define SDRAM_DLB_EVICTION_OFFS 0x30c
+#define SDRAM_DLB_EVICTION_THRESHOLD_MASK 0xff
+
+static void (*mvebu_board_pm_enter)(void __iomem *sdram_reg, u32 srcmd);
+static void __iomem *sdram_ctrl;
+
+static int mvebu_pm_powerdown(unsigned long data)
+{
+ u32 reg, srcmd;
+
+ flush_cache_all();
+ outer_flush_all();
+
+ /*
+ * Issue a Data Synchronization Barrier instruction to ensure
+ * that all state saving has been completed.
+ */
+ dsb();
+
+ /* Flush the DLB and wait ~7 usec */
+ reg = readl(sdram_ctrl + SDRAM_DLB_EVICTION_OFFS);
+ reg &= ~SDRAM_DLB_EVICTION_THRESHOLD_MASK;
+ writel(reg, sdram_ctrl + SDRAM_DLB_EVICTION_OFFS);
+
+ udelay(7);
+
+ /* Set DRAM in battery backup mode */
+ reg = readl(sdram_ctrl + SDRAM_CONFIG_OFFS);
+ reg &= ~SDRAM_CONFIG_SR_MODE_BIT;
+ writel(reg, sdram_ctrl + SDRAM_CONFIG_OFFS);
+
+ /* Prepare to go to self-refresh */
+
+ srcmd = readl(sdram_ctrl + SDRAM_OPERATION_OFFS);
+ srcmd &= ~0x1F;
+ srcmd |= SDRAM_OPERATION_SELF_REFRESH;
+
+ mvebu_board_pm_enter(sdram_ctrl + SDRAM_OPERATION_OFFS, srcmd);
+
+ return 0;
+}
+
+#define BOOT_INFO_ADDR 0x3000
+#define BOOT_MAGIC_WORD 0xdeadb002
+#define BOOT_MAGIC_LIST_END 0xffffffff
+
+/*
+ * Those registers are accessed before switching the internal register
+ * base, which is why we hardcode the 0xd0000000 base address, the one
+ * used by the SoC out of reset.
+ */
+#define MBUS_WINDOW_12_CTRL 0xd00200b0
+#define MBUS_INTERNAL_REG_ADDRESS 0xd0020080
+
+#define SDRAM_WIN_BASE_REG(x) (0x20180 + (0x8*x))
+#define SDRAM_WIN_CTRL_REG(x) (0x20184 + (0x8*x))
+
+static phys_addr_t mvebu_internal_reg_base(void)
+{
+ struct device_node *np;
+ __be32 in_addr[2];
+
+ np = of_find_node_by_name(NULL, "internal-regs");
+ BUG_ON(!np);
+
+ /*
+ * Ask the DT what is the internal register address on this
+ * platform. In the mvebu-mbus DT binding, 0xf0010000
+ * corresponds to the internal register window.
+ */
+ in_addr[0] = cpu_to_be32(0xf0010000);
+ in_addr[1] = 0x0;
+
+ return of_translate_address(np, in_addr);
+}
+
+static void mvebu_pm_store_bootinfo(void)
+{
+ u32 *store_addr;
+ phys_addr_t resume_pc;
+
+ store_addr = phys_to_virt(BOOT_INFO_ADDR);
+ resume_pc = virt_to_phys(armada_370_xp_cpu_resume);
+
+ /*
+ * The bootloader expects the first two words to be a magic
+ * value (BOOT_MAGIC_WORD), followed by the address of the
+ * resume code to jump to. Then, it expects a sequence of
+ * (address, value) pairs, which can be used to restore the
+ * value of certain registers. This sequence must end with the
+ * BOOT_MAGIC_LIST_END magic value.
+ */
+
+ writel(BOOT_MAGIC_WORD, store_addr++);
+ writel(resume_pc, store_addr++);
+
+ /*
+ * Some platforms remap their internal register base address
+ * to 0xf1000000. However, out of reset, window 12 starts at
+ * 0xf0000000 and ends at 0xf7ffffff, which would overlap with
+ * the internal registers. Therefore, disable window 12.
+ */
+ writel(MBUS_WINDOW_12_CTRL, store_addr++);
+ writel(0x0, store_addr++);
+
+ /*
+ * Set the internal register base address to the value
+ * expected by Linux, as read from the Device Tree.
+ */
+ writel(MBUS_INTERNAL_REG_ADDRESS, store_addr++);
+ writel(mvebu_internal_reg_base(), store_addr++);
+
+ /*
+ * Ask the mvebu-mbus driver to store the SDRAM window
+ * configuration, which has to be restored by the bootloader
+ * before re-entering the kernel on resume.
+ */
+ store_addr += mvebu_mbus_save_cpu_target(store_addr);
+
+ writel(BOOT_MAGIC_LIST_END, store_addr);
+}
+
+static int mvebu_pm_enter(suspend_state_t state)
+{
+ if (state != PM_SUSPEND_MEM)
+ return -EINVAL;
+
+ cpu_pm_enter();
+ cpu_cluster_pm_enter();
+
+ mvebu_pm_store_bootinfo();
+ cpu_suspend(0, mvebu_pm_powerdown);
+
+ outer_resume();
+
+ mvebu_v7_pmsu_idle_exit();
+
+ set_cpu_coherent();
+
+ cpu_cluster_pm_exit();
+ cpu_pm_exit();
+
+ return 0;
+}
+
+static const struct platform_suspend_ops mvebu_pm_ops = {
+ .enter = mvebu_pm_enter,
+ .valid = suspend_valid_only_mem,
+};
+
+int mvebu_pm_init(void (*board_pm_enter)(void __iomem *sdram_reg, u32 srcmd))
+{
+ struct device_node *np;
+ struct resource res;
+
+ if (!of_machine_is_compatible("marvell,armadaxp"))
+ return -ENODEV;
+
+ np = of_find_compatible_node(NULL, NULL,
+ "marvell,armada-xp-sdram-controller");
+ if (!np)
+ return -ENODEV;
+
+ if (of_address_to_resource(np, 0, &res)) {
+ of_node_put(np);
+ return -ENODEV;
+ }
+
+ if (!request_mem_region(res.start, resource_size(&res),
+ np->full_name)) {
+ of_node_put(np);
+ return -EBUSY;
+ }
+
+ sdram_ctrl = ioremap(res.start, resource_size(&res));
+ if (!sdram_ctrl) {
+ release_mem_region(res.start, resource_size(&res));
+ of_node_put(np);
+ return -ENOMEM;
+ }
+
+ of_node_put(np);
+
+ mvebu_board_pm_enter = board_pm_enter;
+
+ suspend_set_ops(&mvebu_pm_ops);
+
+ return 0;
+}
diff --git a/arch/arm/mach-mvebu/pmsu.h b/arch/arm/mach-mvebu/pmsu.h
index 6b58c1f..a7c242d 100644
--- a/arch/arm/mach-mvebu/pmsu.h
+++ b/arch/arm/mach-mvebu/pmsu.h
@@ -17,5 +17,6 @@ int mvebu_setup_boot_addr_wa(unsigned int crypto_eng_target,
phys_addr_t resume_addr_reg);
void mvebu_v7_pmsu_idle_exit(void);
+void armada_370_xp_cpu_resume(void);
#endif /* __MACH_370_XP_PMSU_H */
--
2.0.0
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