regmap-irq: Introduce inverted status registers support

Some interrupt controllers have inverted status register:
cleared bits is active interrupts and set bits is inactive interrupts,
so add inverted status support to the framework.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>

drivers/base/regmap/regmap-irq.c

@@ -531,6 +531,10 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 		}
 	}
 
+	if (chip->status_invert)
+		for (i = 0; i < data->chip->num_regs; i++)
+			data->status_buf[i] = ~data->status_buf[i];
+
 	/*
 	 * Ignore masked IRQs and ack if we need to; we ack early so
 	 * there is no race between handling and acknowleding the
@@ -800,6 +804,9 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			goto err_alloc;
 		}
 
+		if (chip->status_invert)
+			data->status_buf[i] = ~data->status_buf[i];
+
 		if (d->status_buf[i] && (chip->ack_base || chip->use_ack)) {
 			reg = sub_irq_reg(d, d->chip->ack_base, i);
 			if (chip->ack_invert)

include/linux/regmap.h

@@ -1449,6 +1449,7 @@ struct regmap_irq_sub_irq_map {
  * @not_fixed_stride: Used when chip peripherals are not laid out with fixed
  * 		      stride. Must be used with sub_reg_offsets containing the
  * 		      offsets to each peripheral.
+ * @status_invert: Inverted status register: cleared bits are active interrupts.
  * @runtime_pm:  Hold a runtime PM lock on the device when accessing it.
  *
  * @num_regs:    Number of registers in each control bank.
@@ -1501,6 +1502,7 @@ struct regmap_irq_chip {
 	bool type_in_mask:1;
 	bool clear_on_unmask:1;
 	bool not_fixed_stride:1;
+	bool status_invert:1;
 
 	int num_regs;