clk: at91: implement suspend/resume for the PMC irqchip

The irq line used by the PMC block is shared with several peripherals
including the init timer which is registering its handler with
IRQF_NO_SUSPEND.

Implement the appropriate suspend/resume callback for the PMC irqchip,
and inform irq core that PMC irq handler can be safely called while
the system is suspended by setting IRQF_COND_SUSPEND.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

2 files changed, 20 insertions, 1 deletions

diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index f07c8152e5cc..3f27d21fb729 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -89,12 +89,29 @@ static int pmc_irq_set_type(struct irq_data *d, unsigned type)
         return 0;
 }
 
+static void pmc_irq_suspend(struct irq_data *d)
+{
+        struct at91_pmc *pmc = irq_data_get_irq_chip_data(d);
+
+        pmc->imr = pmc_read(pmc, AT91_PMC_IMR);
+        pmc_write(pmc, AT91_PMC_IDR, pmc->imr);
+}
+
+static void pmc_irq_resume(struct irq_data *d)
+{
+        struct at91_pmc *pmc = irq_data_get_irq_chip_data(d);
+
+        pmc_write(pmc, AT91_PMC_IER, pmc->imr);
+}
+
 static struct irq_chip pmc_irq = {
         .name = "PMC",
         .irq_disable = pmc_irq_mask,
         .irq_mask = pmc_irq_mask,
         .irq_unmask = pmc_irq_unmask,
         .irq_set_type = pmc_irq_set_type,
+        .irq_suspend = pmc_irq_suspend,
+        .irq_resume = pmc_irq_resume,
 };
 
 static struct lock_class_key pmc_lock_class;
@@ -224,7 +241,8 @@ static struct at91_pmc *__init at91_pmc_init(struct device_node *np,
                 goto out_free_pmc;
 
         pmc_write(pmc, AT91_PMC_IDR, 0xffffffff);
-        if (request_irq(pmc->virq, pmc_irq_handler, IRQF_SHARED, "pmc", pmc))
+        if (request_irq(pmc->virq, pmc_irq_handler,
+                        IRQF_SHARED | IRQF_COND_SUSPEND, "pmc", pmc))
                 goto out_remove_irqdomain;
 
         return pmc;
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index 52d2041fa3f6..69abb08cf146 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -33,6 +33,7 @@ struct at91_pmc {
         spinlock_t lock;
         const struct at91_pmc_caps *caps;
         struct irq_domain *irqdomain;
+        u32 imr;
 };
 
 static inline void pmc_lock(struct at91_pmc *pmc)