arm/imx6q: add suspend/resume support

It adds suspend/resume support for imx6q.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

4 files changed, 108 insertions, 1 deletions

diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 994ae82ca281..aba73214c2a8 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -70,4 +70,4 @@ AFLAGS_head-v7.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SMP) += platsmp.o
 obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
 obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o
-obj-$(CONFIG_SOC_IMX6Q) += clock-imx6q.o mach-imx6q.o
+obj-$(CONFIG_SOC_IMX6Q) += clock-imx6q.o mach-imx6q.o pm-imx6q.o
diff --git a/arch/arm/mach-imx/head-v7.S b/arch/arm/mach-imx/head-v7.S
index ede908bca7d5..6229efbc70cb 100644
--- a/arch/arm/mach-imx/head-v7.S
+++ b/arch/arm/mach-imx/head-v7.S
@@ -12,6 +12,7 @@
 
 #include <linux/linkage.h>
 #include <linux/init.h>
+#include <asm/asm-offsets.h>
 #include <asm/hardware/cache-l2x0.h>
 
         .section ".text.head", "ax"
@@ -69,3 +70,30 @@ ENTRY(v7_secondary_startup)
         b       secondary_startup
 ENDPROC(v7_secondary_startup)
 #endif
+
+/*
+ * The following code is located into the .data section.  This is to
+ * allow phys_l2x0_saved_regs to be accessed with a relative load
+ * as we are running on physical address here.
+ */
+        .data
+        .align
+
+        .macro  pl310_resume
+        ldr     r2, phys_l2x0_saved_regs
+        ldr     r0, [r2, #L2X0_R_PHY_BASE]      @ get physical base of l2x0
+        ldr     r1, [r2, #L2X0_R_AUX_CTRL]      @ get aux_ctrl value
+        str     r1, [r0, #L2X0_AUX_CTRL]        @ restore aux_ctrl
+        mov     r1, #0x1
+        str     r1, [r0, #L2X0_CTRL]            @ re-enable L2
+        .endm
+
+ENTRY(v7_cpu_resume)
+        bl      v7_invalidate_l1
+        pl310_resume
+        b       cpu_resume
+ENDPROC(v7_cpu_resume)
+
+        .globl  phys_l2x0_saved_regs
+phys_l2x0_saved_regs:
+        .long   0
diff --git a/arch/arm/mach-imx/pm-imx6q.c b/arch/arm/mach-imx/pm-imx6q.c
new file mode 100644
index 000000000000..f20f191d7cca
--- /dev/null
+++ b/arch/arm/mach-imx/pm-imx6q.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/suspend.h>
+#include <asm/cacheflush.h>
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/hardware/cache-l2x0.h>
+#include <mach/common.h>
+#include <mach/hardware.h>
+
+extern unsigned long phys_l2x0_saved_regs;
+
+static int imx6q_suspend_finish(unsigned long val)
+{
+        cpu_do_idle();
+        return 0;
+}
+
+static int imx6q_pm_enter(suspend_state_t state)
+{
+        switch (state) {
+        case PM_SUSPEND_MEM:
+                imx6q_set_lpm(STOP_POWER_OFF);
+                imx_gpc_pre_suspend();
+                imx_set_cpu_jump(0, v7_cpu_resume);
+                /* Zzz ... */
+                cpu_suspend(0, imx6q_suspend_finish);
+                imx_smp_prepare();
+                imx_gpc_post_resume();
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static const struct platform_suspend_ops imx6q_pm_ops = {
+        .enter = imx6q_pm_enter,
+        .valid = suspend_valid_only_mem,
+};
+
+void __init imx6q_pm_init(void)
+{
+        /*
+         * The l2x0 core code provides an infrastucture to save and restore
+         * l2x0 registers across suspend/resume cycle.  But because imx6q
+         * retains L2 content during suspend and needs to resume L2 before
+         * MMU is enabled, it can only utilize register saving support and
+         * have to take care of restoring on its own.  So we save physical
+         * address of the data structure used by l2x0 core to save registers,
+         * and later restore the necessary ones in imx6q resume entry.
+         */
+        phys_l2x0_saved_regs = __pa(&l2x0_saved_regs);
+
+        suspend_set_ops(&imx6q_pm_ops);
+}
diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h
index 607b4623af0c..6a7d993a17a6 100644
--- a/arch/arm/plat-mxc/include/mach/common.h
+++ b/arch/arm/plat-mxc/include/mach/common.h
@@ -13,6 +13,7 @@
 
 struct platform_device;
 struct clk;
+enum mxc_cpu_pwr_mode;
 
 extern void mx1_map_io(void);
 extern void mx21_map_io(void);
@@ -107,14 +108,22 @@ extern void imx_lluart_map_io(void);
 #else
 static inline void imx_lluart_map_io(void) {}
 #endif
+extern void v7_cpu_resume(void);
+extern u32 *pl310_get_save_ptr(void);
 #ifdef CONFIG_SMP
 extern void v7_secondary_startup(void);
 extern void imx_scu_map_io(void);
+extern void imx_smp_prepare(void);
 #else
 static inline void imx_scu_map_io(void) {}
+static inline void imx_smp_prepare(void) {}
 #endif
 extern void imx_enable_cpu(int cpu, bool enable);
 extern void imx_set_cpu_jump(int cpu, void *jump_addr);
 extern void imx_src_init(void);
 extern void imx_gpc_init(void);
+extern void imx_gpc_pre_suspend(void);
+extern void imx_gpc_post_resume(void);
+extern int imx6q_set_lpm(enum mxc_cpu_pwr_mode mode);
+extern void imx6q_pm_init(void);
 #endif