ARM: OMAP2+: mux: add support for PAD wakeup interrupts

OMAP mux now parses active wakeup events from pad registers and calls
corresponding hwmod ISRs once a wakeup is detected. This is
accomplished by registering an interrupt handler for PRCM IO event,
which is raised every time the HW detects wakeups.

[paul@pwsan.com: This patch is a merge of Govindraj R's "ARM: OMAP2+:
hwmod: Add API to check IO PAD wakeup status" patch, Tero Kristo's
"ARM: OMAP2+: mux: add support for PAD wakeup interrupts" patch, and
part of Tero's "ARM: OMAP: mux: add support for selecting mpu_irq for
each wakeup pad" patch.]

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: Govindraj.R <govindraj.raja@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
[paul@pwsan.com: reduced indentation level; renamed omap_hwmod function;
 improved function documentation; modified to iterate only through dynamic
 pads; modified to skip pads where idle mode doesn't enable wakeups; split
 patches]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/mux.c b/arch/arm/mach-omap2/mux.c
index a474c81355ec..e1cc75d1a57a 100644
--- a/arch/arm/mach-omap2/mux.c
+++ b/arch/arm/mach-omap2/mux.c
@@ -32,6 +32,8 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
 
 #include <asm/system.h>
 
@@ -39,6 +41,7 @@
 
 #include "control.h"
 #include "mux.h"
+#include "prm.h"
 
 #define OMAP_MUX_BASE_OFFSET            0x30    /* Offset from CTRL_BASE */
 #define OMAP_MUX_BASE_SZ                0x5ca
@@ -353,6 +356,78 @@ err1:
         return NULL;
 }
 
+/**
+ * omap_hwmod_mux_scan_wakeups - omap hwmod scan wakeup pads
+ * @hmux: Pads for a hwmod
+ * @mpu_irqs: MPU irq array for a hwmod
+ *
+ * Scans the wakeup status of pads for a single hwmod.  If an irq
+ * array is defined for this mux, the parser will call the registered
+ * ISRs for corresponding pads, otherwise the parser will stop at the
+ * first wakeup active pad and return.  Returns true if there is a
+ * pending and non-served wakeup event for the mux, otherwise false.
+ */
+static bool omap_hwmod_mux_scan_wakeups(struct omap_hwmod_mux_info *hmux,
+                struct omap_hwmod_irq_info *mpu_irqs)
+{
+        int i, irq;
+        unsigned int val;
+        u32 handled_irqs = 0;
+
+        for (i = 0; i < hmux->nr_pads_dynamic; i++) {
+                struct omap_device_pad *pad = hmux->pads_dynamic[i];
+
+                if (!(pad->flags & OMAP_DEVICE_PAD_WAKEUP) ||
+                    !(pad->idle & OMAP_WAKEUP_EN))
+                        continue;
+
+                val = omap_mux_read(pad->partition, pad->mux->reg_offset);
+                if (!(val & OMAP_WAKEUP_EVENT))
+                        continue;
+
+                if (!hmux->irqs)
+                        return true;
+
+                irq = hmux->irqs[i];
+                /* make sure we only handle each irq once */
+                if (handled_irqs & 1 << irq)
+                        continue;
+
+                handled_irqs |= 1 << irq;
+
+                generic_handle_irq(mpu_irqs[irq].irq);
+        }
+
+        return false;
+}
+
+/**
+ * _omap_hwmod_mux_handle_irq - Process wakeup events for a single hwmod
+ *
+ * Checks a single hwmod for every wakeup capable pad to see if there is an
+ * active wakeup event. If this is the case, call the corresponding ISR.
+ */
+static int _omap_hwmod_mux_handle_irq(struct omap_hwmod *oh, void *data)
+{
+        if (!oh->mux || !oh->mux->enabled)
+                return 0;
+        if (omap_hwmod_mux_scan_wakeups(oh->mux, oh->mpu_irqs))
+                generic_handle_irq(oh->mpu_irqs[0].irq);
+        return 0;
+}
+
+/**
+ * omap_hwmod_mux_handle_irq - Process pad wakeup irqs.
+ *
+ * Calls a function for each registered omap_hwmod to check
+ * pad wakeup statuses.
+ */
+static irqreturn_t omap_hwmod_mux_handle_irq(int irq, void *unused)
+{
+        omap_hwmod_for_each(_omap_hwmod_mux_handle_irq, NULL);
+        return IRQ_HANDLED;
+}
+
 /* Assumes the calling function takes care of locking */
 void omap_hwmod_mux(struct omap_hwmod_mux_info *hmux, u8 state)
 {
@@ -717,6 +792,7 @@ static void __init omap_mux_free_names(struct omap_mux *m)
 static int __init omap_mux_late_init(void)
 {
         struct omap_mux_partition *partition;
+        int ret;
 
         list_for_each_entry(partition, &mux_partitions, node) {
                 struct omap_mux_entry *e, *tmp;
@@ -737,6 +813,13 @@ static int __init omap_mux_late_init(void)
                 }
         }
 
+        ret = request_irq(omap_prcm_event_to_irq("io"),
+                omap_hwmod_mux_handle_irq, IRQF_SHARED | IRQF_NO_SUSPEND,
+                        "hwmod_io", omap_mux_late_init);
+
+        if (ret)
+                pr_warning("mux: Failed to setup hwmod io irq %d\n", ret);
+
         omap_mux_dbg_init();
 
         return 0;