[PATCH v2 6/6] arm/imx6q: add suspend/resume support

[Shawn Guo]

It adds suspend/resume support for imx6q.

Signed-off-by: Anson Huang <b20788 at freescale.com>
Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
---
 arch/arm/mach-imx/Makefile              |    2 +-
 arch/arm/mach-imx/head-v7.S             |   27 +++++++++
 arch/arm/mach-imx/pm-imx6q.c            |   88 +++++++++++++++++++++++++++++++
 arch/arm/plat-mxc/include/mach/common.h |    8 +++
 4 files changed, 124 insertions(+), 1 deletions(-)
 create mode 100644 arch/arm/mach-imx/pm-imx6q.c

diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 16737ba..c787151 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -70,4 +70,4 @@ obj-$(CONFIG_CPU_V7) += head-v7.o
 obj-$(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 ede908b..0a86685 100644
--- a/arch/arm/mach-imx/head-v7.S
+++ b/arch/arm/mach-imx/head-v7.S
@@ -69,3 +69,30 @@ ENTRY(v7_secondary_startup)
 	b	secondary_startup
 ENDPROC(v7_secondary_startup)
 #endif
+
+ENTRY(v7_cpu_resume)
+	bl	v7_invalidate_l1
+
+	/*
+	 * Restore L2 AUX_CTRL register saved by suspend procedure
+	 * and enable L2
+	 */
+	adr	r4, 1f
+	ldmia	r4, {r5, r6, r7}
+	sub	r4, r4, r5
+	add	r6, r6, r4
+	add	r7, r7, r4
+	ldr	r0, [r6]
+	ldr	r7, [r7]
+	ldr	r1, [r7]
+	str	r1, [r0, #L2X0_AUX_CTRL]
+	ldr	r1, =0x1
+	str	r1, [r0, #L2X0_CTRL]
+
+	b	cpu_resume
+
+	.align
+1:	.long	.
+	.long	pl310_pbase
+	.long	pl310_aux_ctrl_paddr
+ENDPROC(v7_cpu_resume)
diff --git a/arch/arm/mach-imx/pm-imx6q.c b/arch/arm/mach-imx/pm-imx6q.c
new file mode 100644
index 0000000..124bcd5
--- /dev/null
+++ b/arch/arm/mach-imx/pm-imx6q.c
@@ -0,0 +1,88 @@
+/*
+ * 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/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/hardware/cache-l2x0.h>
+#include <mach/common.h>
+#include <mach/hardware.h>
+
+static void __iomem *pl310_vbase;
+void __iomem *pl310_pbase;
+
+static volatile unsigned long pl310_aux_ctrl;
+volatile unsigned long pl310_aux_ctrl_paddr;
+
+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)
+{
+	struct device_node *np;
+	u32 reg[2];
+
+	np = of_find_compatible_node(NULL, NULL, "arm,pl310-cache");
+	of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
+	pl310_vbase = ioremap(reg[0], reg[1]);
+	WARN_ON(!pl310_vbase);
+	pl310_pbase = (void __iomem *) reg[0];
+
+	/*
+	 * On imx6q, during system suspend, ARM core gets powered off,
+	 * but L2 cache is retained.  To avoid cleaning the entire L2,
+	 * we need to save L2 controller registers, and when system gets
+	 * woke up, restore the registers and re-enable L2 before
+	 * calling into cpu_resume().
+	 *
+	 * Most of pl310 configuration upon reset work just fine for
+	 * imx6q, and the only one register we actually need to save is
+	 * AUX_CTRL.  Also since pl310 configuration won't change in a
+	 * live system, we can save it here only once, and restore it
+	 * at resume entry v7_cpu_resume() which runs in physical
+	 * address space.
+	 */
+	pl310_aux_ctrl = readl_relaxed(pl310_vbase + L2X0_AUX_CTRL);
+	pl310_aux_ctrl_paddr = __pa(&pl310_aux_ctrl);
+
+	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 9c5be7b..6673d7d 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);
@@ -79,14 +80,21 @@ extern void imx_lluart_map_io(void);
 #else
 static inline void imx_lluart_map_io(void) {}
 #endif
+extern void v7_cpu_resume(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
-- 
1.7.4.1