regmap: irq: add support for chips who have separate unmask registers

Some chips have separate unmask registers from mask registers for
some consideration of concurrency SMP write performance. And this
patch adds a flag for it.

An user will be CSR SiRFSoC ARM chips.

Signed-off-by: Guo Zeng <Guo.Zeng@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/base/regmap/regmap-irq.c

@@ -63,6 +63,7 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 	struct regmap *map = d->map;
 	int i, ret;
 	u32 reg;
+	u32 unmask_offset;
 
 	if (d->chip->runtime_pm) {
 		ret = pm_runtime_get_sync(map->dev);
@@ -79,12 +80,28 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 	for (i = 0; i < d->chip->num_regs; i++) {
 		reg = d->chip->mask_base +
 			(i * map->reg_stride * d->irq_reg_stride);
-		if (d->chip->mask_invert)
+		if (d->chip->mask_invert) {
 			ret = regmap_update_bits(d->map, reg,
 					 d->mask_buf_def[i], ~d->mask_buf[i]);
-		else
+		} else if (d->chip->unmask_base) {
+			/* set mask with mask_base register */
+			ret = regmap_update_bits(d->map, reg,
+					d->mask_buf_def[i], ~d->mask_buf[i]);
+			if (ret < 0)
+				dev_err(d->map->dev,
+					"Failed to sync unmasks in %x\n",
+					reg);
+			unmask_offset = d->chip->unmask_base -
+							d->chip->mask_base;
+			/* clear mask with unmask_base register */
+			ret = regmap_update_bits(d->map,
+					reg + unmask_offset,
+					d->mask_buf_def[i],
+					d->mask_buf[i]);
+		} else {
 			ret = regmap_update_bits(d->map, reg,
 					 d->mask_buf_def[i], d->mask_buf[i]);
+		}
 		if (ret != 0)
 			dev_err(d->map->dev, "Failed to sync masks in %x\n",
 				reg);
@@ -339,6 +356,7 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 	int i;
 	int ret = -ENOMEM;
 	u32 reg;
+	u32 unmask_offset;
 
 	if (chip->num_regs <= 0)
 		return -EINVAL;
@@ -420,7 +438,14 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 		if (chip->mask_invert)
 			ret = regmap_update_bits(map, reg,
 					 d->mask_buf[i], ~d->mask_buf[i]);
-		else
+		else if (d->chip->unmask_base) {
+			unmask_offset = d->chip->unmask_base -
+					d->chip->mask_base;
+			ret = regmap_update_bits(d->map,
+					reg + unmask_offset,
+					d->mask_buf[i],
+					d->mask_buf[i]);
+		} else
 			ret = regmap_update_bits(map, reg,
 					 d->mask_buf[i], d->mask_buf[i]);
 		if (ret != 0) {

include/linux/regmap.h

@@ -800,6 +800,8 @@ struct regmap_irq {
  *
  * @status_base: Base status register address.
  * @mask_base:   Base mask register address.
+ * @unmask_base:  Base unmask register address. for chips who have
+ *                separate mask and unmask registers
  * @ack_base:    Base ack address. If zero then the chip is clear on read.
  *               Using zero value is possible with @use_ack bit.
  * @wake_base:   Base address for wake enables.  If zero unsupported.
@@ -820,6 +822,7 @@ struct regmap_irq_chip {
 
 	unsigned int status_base;
 	unsigned int mask_base;
+	unsigned int unmask_base;
 	unsigned int ack_base;
 	unsigned int wake_base;
 	unsigned int irq_reg_stride;