ARM: OMAP: PRCM: add suspend prepare / finish support

PRCM chain handler needs to disable forwarding of interrupts during
suspend, because runtime PM is disabled and most of the drivers
are potentially not able to handle interrupts coming at this time.

This patch masks all the PRCM interrupt events if a PRCM interrupt
occurs during suspend, but does not ack them. Once suspend finish
is called, all the masked events will be re-enabled, which causes
immediate PRCM interrupt and handles the postponed event.

The suspend prepare and complete  callbacks will be called from
pm34xx.c / pm44xx.c files in the following patches.

The functions defined in this patch should eventually be moved to
suspend->prepare and suspend->finish driver hooks, once the PRCM
chain handler will be made as its own driver.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
[paul@pwsan.com: add kerneldoc, add omap_prcm_irq_setup.saved_mask, add fn
 ptrs for save_and_clear_irqen() and restore_irqen()]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/prcm-common.h b/arch/arm/mach-omap2/prcm-common.h
index 76db3795e68f..0f69d8fc5628 100644
--- a/arch/arm/mach-omap2/prcm-common.h
+++ b/arch/arm/mach-omap2/prcm-common.h
@@ -437,11 +437,16 @@ struct omap_prcm_irq {
  * @irq: MPU IRQ asserted when a PRCM interrupt arrives
  * @read_pending_irqs: fn ptr to determine if any PRCM IRQs are pending
  * @ocp_barrier: fn ptr to force buffered PRM writes to complete
+ * @save_and_clear_irqen: fn ptr to save and clear IRQENABLE regs
+ * @restore_irqen: fn ptr to save and clear IRQENABLE regs
+ * @saved_mask: IRQENABLE regs are saved here during suspend
  * @priority_mask: 1 bit per IRQ, set to 1 if omap_prcm_irq.priority = true
  * @base_irq: base dynamic IRQ number, returned from irq_alloc_descs() in init
+ * @suspended: set to true after Linux suspend code has called our ->prepare()
+ * @suspend_save_flag: set to true after IRQ masks have been saved and disabled
  *
- * @priority_mask and @base_irq are populated dynamically during
- * omap_prcm_register_chain_handler() - these fields are not to be
+ * @saved_mask, @priority_mask, @base_irq, @suspended, and
+ * @suspend_save_flag are populated dynamically, and are not to be
  * specified in static initializers.
  */
 struct omap_prcm_irq_setup {
@@ -453,8 +458,13 @@ struct omap_prcm_irq_setup {
         int irq;
         void (*read_pending_irqs)(unsigned long *events);
         void (*ocp_barrier)(void);
+        void (*save_and_clear_irqen)(u32 *saved_mask);
+        void (*restore_irqen)(u32 *saved_mask);
+        u32 *saved_mask;
         u32 *priority_mask;
         int base_irq;
+        bool suspended;
+        bool suspend_save_flag;
 };
 
 /* OMAP_PRCM_IRQ: convenience macro for creating struct omap_prcm_irq records */
@@ -468,6 +478,8 @@ extern void omap_prcm_irq_cleanup(void);
 extern int omap_prcm_register_chain_handler(
         struct omap_prcm_irq_setup *irq_setup);
 extern int omap_prcm_event_to_irq(const char *event);
+extern void omap_prcm_irq_prepare(void);
+extern void omap_prcm_irq_complete(void);
 
 # endif