Merge remote-tracking branch 'regmap/topic/ack' into regmap-next

drivers/base/regmap/regmap-irq.c

···
 		 * OR if there is masked interrupt which hasn't been Acked,
 		 * it'll be ignored in irq handler, then may introduce irq storm
 		 */
-		if (d->mask_buf[i] && d->chip->ack_base) {
+		if (d->mask_buf[i] && (d->chip->ack_base || d->chip->use_ack)) {
 			reg = d->chip->ack_base +
 				(i * map->reg_stride * d->irq_reg_stride);
 			ret = regmap_write(map, reg, d->mask_buf[i]);
···
 	for (i = 0; i < data->chip->num_regs; i++) {
 		data->status_buf[i] &= ~data->mask_buf[i];
 
-		if (data->status_buf[i] && chip->ack_base) {
+		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]);
···
 			goto err_alloc;
 		}
 
-		if (d->status_buf[i] && chip->ack_base) {
+		if (d->status_buf[i] && (chip->ack_base || chip->use_ack)) {
 			reg = chip->ack_base +
 				(i * map->reg_stride * d->irq_reg_stride);
 			ret = regmap_write(map, reg,

include/linux/regmap.h

···
  *
  * @status_base: Base status register address.
  * @mask_base:   Base mask register address.
- * @ack_base:    Base ack address.  If zero then the chip is clear on read.
+ * @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.
  * @irq_reg_stride:  Stride to use for chips where registers are not contiguous.
  * @init_ack_masked: Ack all masked interrupts once during initalization.
  * @mask_invert: Inverted mask register: cleared bits are masked out.
+ * @use_ack:     Use @ack register even if it is zero.
  * @wake_invert: Inverted wake register: cleared bits are wake enabled.
  * @runtime_pm:  Hold a runtime PM lock on the device when accessing it.
  *
···
 	unsigned int irq_reg_stride;
 	bool init_ack_masked:1;
 	bool mask_invert:1;
+	bool use_ack:1;
 	bool wake_invert:1;
 	bool runtime_pm:1;