[PATCH 2/2] regmap: irq: add support to have callback pre/post irq handling

[Laxman Dewangan <ldewangan@nvidia.com>]

Some of devices like MAXIM MAX77620 required to have the chip
specific configuration before processing interrupt and after
interrupt handling is done.

For such devices to use the generic regmap-irq, add callback APIs
for pre/post irq callback which gets called from interrupt handler
of regmap irq thread to have device specific configurations.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
---
 drivers/base/regmap/regmap-irq.c | 15 +++++++++++----
 include/linux/regmap.h           | 11 +++++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index 8aa1e2a..00dc6e9 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -268,13 +268,16 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 	bool handled = false;
 	u32 reg;
 
+	if (chip->pre_irq)
+		chip->pre_irq(chip->pre_post_irq_data);
+
 	if (chip->runtime_pm) {
 		ret = pm_runtime_get_sync(map->dev);
 		if (ret < 0) {
 			dev_err(map->dev, "IRQ thread failed to resume: %d\n",
 				ret);
 			pm_runtime_put(map->dev);
-			return IRQ_NONE;
+			goto exit;
 		}
 	}
 
@@ -296,7 +299,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 		if (ret != 0) {
 			dev_err(map->dev, "Failed to read IRQ status: %d\n",
 				ret);
-			return IRQ_NONE;
+			goto exit;
 		}
 
 		for (i = 0; i < data->chip->num_regs; i++) {
@@ -312,7 +315,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 				break;
 			default:
 				BUG();
-				return IRQ_NONE;
+				goto exit;
 			}
 		}
 
@@ -329,7 +332,7 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 					ret);
 				if (chip->runtime_pm)
 					pm_runtime_put(map->dev);
-				return IRQ_NONE;
+				goto exit;
 			}
 		}
 	}
@@ -365,6 +368,10 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 	if (chip->runtime_pm)
 		pm_runtime_put(map->dev);
 
+exit:
+	if (chip->post_irq)
+		chip->post_irq(chip->pre_post_irq_data);
+
 	if (handled)
 		return IRQ_HANDLED;
 	else
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 1839434..ba2d30b 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -834,6 +834,13 @@ struct regmap_irq {
  * @num_type_reg:    Number of type registers.
  * @type_reg_stride: Stride to use for chips where type registers are not
  *			contiguous.
+ * @pre_irq:	The callback that is to be executed initially, before the main
+ *		handling in regmap irq	handler when an interrupt occurs.
+ * @post_irq:	The callback that is to be executed after the main handling in
+ *		the regmap irq handler when an interrupt occurs.
+ * @pre_post_irq_data: The driver specific data that is the parameter for the
+ *		pre_irq and post_irq callbacks.
+ *
  */
 struct regmap_irq_chip {
 	const char *name;
@@ -860,6 +867,10 @@ struct regmap_irq_chip {
 
 	int num_type_reg;
 	unsigned int type_reg_stride;
+
+	int (*pre_irq)(void *irq_data);
+	int (*post_irq)(void *irq_data);
+	void *pre_post_irq_data;
 };
 
 struct regmap_irq_chip_data;
-- 
2.1.4