[ARM] VIC: Add power management device

Add power management support to the VIC by registering
each VIC as a system device to get suspend/resume
events going.

Since the VIC registeration is done early, we need to
record the VICs in a static array which is used to add
the system devices later once the initcalls are run. This
means there is now a configuration value for the number
of VICs in the system.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

2 files changed, 221 insertions, 7 deletions

diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index a2cd9beaf37..38518d450bc 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -4,6 +4,13 @@ config ARM_GIC
 config ARM_VIC
         bool
 
+config ARM_VIC_NR
+        int
+        default 2
+        help
+          The maximum number of VICs available in the system, for
+          power management.
+
 config ICST525
         bool
 
diff --git a/arch/arm/common/vic.c b/arch/arm/common/vic.c
index b2a781d9ce0..887c6eb3a18 100644
--- a/arch/arm/common/vic.c
+++ b/arch/arm/common/vic.c
@@ -21,6 +21,7 @@
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/io.h>
+#include <linux/sysdev.h>
 
 #include <asm/mach/irq.h>
 #include <asm/hardware/vic.h>
@@ -39,11 +40,219 @@ static void vic_unmask_irq(unsigned int irq)
         writel(1 << irq, base + VIC_INT_ENABLE);
 }
 
+/**
+ * vic_init2 - common initialisation code
+ * @base: Base of the VIC.
+ *
+ * Common initialisation code for registeration
+ * and resume.
+*/
+static void vic_init2(void __iomem *base)
+{
+        int i;
+
+        for (i = 0; i < 16; i++) {
+                void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4);
+                writel(VIC_VECT_CNTL_ENABLE | i, reg);
+        }
+
+        writel(32, base + VIC_PL190_DEF_VECT_ADDR);
+}
+
+#if defined(CONFIG_PM)
+/**
+ * struct vic_device - VIC PM device
+ * @sysdev: The system device which is registered.
+ * @irq: The IRQ number for the base of the VIC.
+ * @base: The register base for the VIC.
+ * @resume_sources: A bitmask of interrupts for resume.
+ * @resume_irqs: The IRQs enabled for resume.
+ * @int_select: Save for VIC_INT_SELECT.
+ * @int_enable: Save for VIC_INT_ENABLE.
+ * @soft_int: Save for VIC_INT_SOFT.
+ * @protect: Save for VIC_PROTECT.
+ */
+struct vic_device {
+        struct sys_device sysdev;
+
+        void __iomem    *base;
+        int             irq;
+        u32             resume_sources;
+        u32             resume_irqs;
+        u32             int_select;
+        u32             int_enable;
+        u32             soft_int;
+        u32             protect;
+};
+
+/* we cannot allocate memory when VICs are initially registered */
+static struct vic_device vic_devices[CONFIG_ARM_VIC_NR];
+
+static inline struct vic_device *to_vic(struct sys_device *sys)
+{
+        return container_of(sys, struct vic_device, sysdev);
+}
+
+static int vic_id;
+
+static int vic_class_resume(struct sys_device *dev)
+{
+        struct vic_device *vic = to_vic(dev);
+        void __iomem *base = vic->base;
+
+        printk(KERN_DEBUG "%s: resuming vic at %p\n", __func__, base);
+
+        /* re-initialise static settings */
+        vic_init2(base);
+
+        writel(vic->int_select, base + VIC_INT_SELECT);
+        writel(vic->protect, base + VIC_PROTECT);
+
+        /* set the enabled ints and then clear the non-enabled */
+        writel(vic->int_enable, base + VIC_INT_ENABLE);
+        writel(~vic->int_enable, base + VIC_INT_ENABLE_CLEAR);
+
+        /* and the same for the soft-int register */
+
+        writel(vic->soft_int, base + VIC_INT_SOFT);
+        writel(~vic->soft_int, base + VIC_INT_SOFT_CLEAR);
+
+        return 0;
+}
+
+static int vic_class_suspend(struct sys_device *dev, pm_message_t state)
+{
+        struct vic_device *vic = to_vic(dev);
+        void __iomem *base = vic->base;
+
+        printk(KERN_DEBUG "%s: suspending vic at %p\n", __func__, base);
+
+        vic->int_select = readl(base + VIC_INT_SELECT);
+        vic->int_enable = readl(base + VIC_INT_ENABLE);
+        vic->soft_int = readl(base + VIC_INT_SOFT);
+        vic->protect = readl(base + VIC_PROTECT);
+
+        /* set the interrupts (if any) that are used for
+         * resuming the system */
+
+        writel(vic->resume_irqs, base + VIC_INT_ENABLE);
+        writel(~vic->resume_irqs, base + VIC_INT_ENABLE_CLEAR);
+
+        return 0;
+}
+
+struct sysdev_class vic_class = {
+        .name           = "vic",
+        .suspend        = vic_class_suspend,
+        .resume         = vic_class_resume,
+};
+
+/**
+ * vic_pm_register - Register a VIC for later power management control
+ * @base: The base address of the VIC.
+ * @irq: The base IRQ for the VIC.
+ * @resume_sources: bitmask of interrupts allowed for resume sources.
+ *
+ * Register the VIC with the system device tree so that it can be notified
+ * of suspend and resume requests and ensure that the correct actions are
+ * taken to re-instate the settings on resume.
+ */
+static void __init vic_pm_register(void __iomem *base, unsigned int irq, u32 resume_sources)
+{
+        struct vic_device *v;
+
+        if (vic_id >= ARRAY_SIZE(vic_devices))
+                printk(KERN_ERR "%s: too few VICs, increase CONFIG_ARM_VIC_NR\n", __func__);
+        else {
+                v = &vic_devices[vic_id];
+                v->base = base;
+                v->resume_sources = resume_sources;
+                v->irq = irq;
+                vic_id++;
+        }
+}
+
+/**
+ * vic_pm_init - initicall to register VIC pm
+ *
+ * This is called via late_initcall() to register
+ * the resources for the VICs due to the early
+ * nature of the VIC's registration.
+*/
+static int __init vic_pm_init(void)
+{
+        struct vic_device *dev = vic_devices;
+        int err;
+        int id;
+
+        if (vic_id == 0)
+                return 0;
+
+        err = sysdev_class_register(&vic_class);
+        if (err) {
+                printk(KERN_ERR "%s: cannot register class\n", __func__);
+                return err;
+        }
+
+        for (id = 0; id < vic_id; id++, dev++) {
+                dev->sysdev.id = id;
+                dev->sysdev.cls = &vic_class;
+
+                err = sysdev_register(&dev->sysdev);
+                if (err) {
+                        printk(KERN_ERR "%s: failed to register device\n",
+                               __func__);
+                        return err;
+                }
+        }
+
+        return 0;
+}
+
+late_initcall(vic_pm_init);
+
+static struct vic_device *vic_from_irq(unsigned int irq)
+{
+        struct vic_device *v = vic_devices;
+        unsigned int base_irq = irq & ~31;
+        int id;
+
+        for (id = 0; id < vic_id; id++, v++) {
+                if (v->irq == base_irq)
+                        return v;
+        }
+
+        return NULL;
+}
+
+static int vic_set_wake(unsigned int irq, unsigned int on)
+{
+        struct vic_device *v = vic_from_irq(irq);
+        unsigned int off = irq & 31;
+
+        if (!v)
+                return -EINVAL;
+
+        if (on)
+                v->resume_irqs |= 1 << off;
+        else
+                v->resume_irqs &= ~(1 << off);
+
+        return 0;
+}
+
+#else
+static inline void vic_pm_register(void __iomem *base, unsigned int irq, u32 arg1) { }
+
+#define vic_set_wake NULL
+#endif /* CONFIG_PM */
+
 static struct irq_chip vic_chip = {
         .name   = "VIC",
         .ack    = vic_mask_irq,
         .mask   = vic_mask_irq,
         .unmask = vic_unmask_irq,
+        .set_wake = vic_set_wake,
 };
 
 /**
@@ -51,9 +260,10 @@ static struct irq_chip vic_chip = {
  * @base: iomem base address
  * @irq_start: starting interrupt number, must be muliple of 32
  * @vic_sources: bitmask of interrupt sources to allow
+ * @resume_sources: bitmask of interrupt sources to allow for resume
  */
 void __init vic_init(void __iomem *base, unsigned int irq_start,
-                     u32 vic_sources)
+                     u32 vic_sources, u32 resume_sources)
 {
         unsigned int i;
 
@@ -77,12 +287,7 @@ void __init vic_init(void __iomem *base, unsigned int irq_start,
                 writel(value, base + VIC_PL190_VECT_ADDR);
         }
 
-        for (i = 0; i < 16; i++) {
-                void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4);
-                writel(VIC_VECT_CNTL_ENABLE | i, reg);
-        }
-
-        writel(32, base + VIC_PL190_DEF_VECT_ADDR);
+        vic_init2(base);
 
         for (i = 0; i < 32; i++) {
                 if (vic_sources & (1 << i)) {
@@ -94,4 +299,6 @@ void __init vic_init(void __iomem *base, unsigned int irq_start,
                         set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
                 }
         }
+
+        vic_pm_register(base, irq_start, resume_sources);
 }