regmap: irq: Add support to clear ack registers

For particular codec HWs have requirement to toggle interrupt clear
register twice 0->1->0. To accommodate it, need to add one more field
(clear_ack) in the regmap_irq struct and update regmap-irq driver to
support it.

Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>
Link: https://lore.kernel.org/r/1601907440-13373-1-git-send-email-lkasam@codeaurora.org
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/base/regmap/regmap-irq.c

@@ -168,6 +168,14 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 				ret = regmap_write(map, reg, ~d->mask_buf[i]);
 			else
 				ret = regmap_write(map, reg, d->mask_buf[i]);
+			if (d->chip->clear_ack) {
+				if (d->chip->ack_invert && !ret)
+					ret = regmap_write(map, reg,
+							   d->mask_buf[i]);
+				else if (!ret)
+					ret = regmap_write(map, reg,
+							   ~d->mask_buf[i]);
+			}
 			if (ret != 0)
 				dev_err(d->map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);
@@ -493,7 +501,20 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 		if (data->status_buf[i] && (chip->ack_base || chip->use_ack)) {
 			reg = chip->ack_base +
 				(i * map->reg_stride * data->irq_reg_stride);
-			ret = regmap_write(map, reg, data->status_buf[i]);
+			if (chip->ack_invert)
+				ret = regmap_write(map, reg,
+						~data->status_buf[i]);
+			else
+				ret = regmap_write(map, reg,
+						data->status_buf[i]);
+			if (chip->clear_ack) {
+				if (chip->ack_invert && !ret)
+					ret = regmap_write(map, reg,
+							data->status_buf[i]);
+				else if (!ret)
+					ret = regmap_write(map, reg,
+							~data->status_buf[i]);
+			}
 			if (ret != 0)
 				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);
@@ -722,6 +743,16 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			else
 				ret = regmap_write(map, reg,
 					d->status_buf[i] & d->mask_buf[i]);
+			if (chip->clear_ack) {
+				if (chip->ack_invert && !ret)
+					ret = regmap_write(map, reg,
+						(d->status_buf[i] &
+						 d->mask_buf[i]));
+				else if (!ret)
+					ret = regmap_write(map, reg,
+						~(d->status_buf[i] &
+						  d->mask_buf[i]));
+			}
 			if (ret != 0) {
 				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);

include/linux/regmap.h

@@ -1355,6 +1355,7 @@ struct regmap_irq_sub_irq_map {
  * @mask_invert: Inverted mask register: cleared bits are masked out.
  * @use_ack:     Use @ack register even if it is zero.
  * @ack_invert:  Inverted ack register: cleared bits for ack.
+ * @clear_ack:  Use this to set 1 and 0 or vice-versa to clear interrupts.
  * @wake_invert: Inverted wake register: cleared bits are wake enabled.
  * @type_invert: Invert the type flags.
  * @type_in_mask: Use the mask registers for controlling irq type. For
@@ -1403,6 +1404,7 @@ struct regmap_irq_chip {
 	bool mask_invert:1;
 	bool use_ack:1;
 	bool ack_invert:1;
+	bool clear_ack:1;
 	bool wake_invert:1;
 	bool runtime_pm:1;
 	bool type_invert:1;