regmap-irq: Add driver callback to configure virtual regs

Enable drivers to configure and modify "virtual" registers, which are
non-standard registers that further configure irq type on some devices.
Since they are non-standard, enable drivers to configure them according
to their particular idiosyncrasies by specifying an optional callback
function while registering with the framework.

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Link: https://lore.kernel.org/r/07e058cdec2297d15c95c825aa0263064d962d5a.1616613838.git.gurus@codeaurora.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Guru Das Srinagesh

drivers/base/regmap/regmap-irq.c

@@ -333,6 +333,11 @@ static int regmap_irq_set_type(struct irq_data *data, unsigned int type)
 	default:
 		return -EINVAL;
 	}
+
+	if (d->chip->set_type_virt)
+		return d->chip->set_type_virt(d->virt_buf, type, data->hwirq,
+					      reg);
+
 	return 0;
 }
 

include/linux/regmap.h

@@ -1426,6 +1426,8 @@ struct regmap_irq_sub_irq_map {
  *		     before regmap_irq_handler process the interrupts.
  * @handle_post_irq: Driver specific callback to handle interrupt from device
  *		     after handling the interrupts in regmap_irq_handler().
+ * @set_type_virt:   Driver specific callback to extend regmap_irq_set_type()
+ *		     and configure virt regs.
  * @irq_drv_data:    Driver specific IRQ data which is passed as parameter when
  *		     driver specific pre/post interrupt handler is called.
  *
@@ -1473,6 +1475,8 @@ struct regmap_irq_chip {
 
 	int (*handle_pre_irq)(void *irq_drv_data);
 	int (*handle_post_irq)(void *irq_drv_data);
+	int (*set_type_virt)(unsigned int **buf, unsigned int type,
+			     unsigned long hwirq, int reg);
 	void *irq_drv_data;
 };