regmap: Fixes for v5.0

The cleanups for the way we handle type information introduced during
 the merge window revealed that we'd been abusing the irq APIs for a long
 time, causing breakage for systems.  This pull request has a couple of
 minimal fixes for that which restore the previous behaviour for the time
 being, we'll fix it properly for v5.1 but that'd be a bit much to do as
 a bug fix.
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Merge tag 'regmap-fix-v5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fixes from Mark Brown:
 "The cleanups for the way we handle type information introduced during
  the merge window revealed that we'd been abusing the irq APIs for a
  long time, causing breakage for systems.

  This has a couple of minimal fixes for that which restore the previous
  behaviour for the time being, we'll fix it properly for v5.1 but
  that'd be a bit much to do as a bug fix"

* tag 'regmap-fix-v5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap-irq: do not write mask register if mask_base is zero
  regmap: regmap-irq: silently ignore unsupported type settings

drivers/base/regmap/regmap-irq.c

@@ -108,6 +108,9 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 	 * suppress pointless writes.
 	 */
 	for (i = 0; i < d->chip->num_regs; i++) {
+		if (!d->chip->mask_base)
+			continue;
+
 		reg = d->chip->mask_base +
 			(i * map->reg_stride * d->irq_reg_stride);
 		if (d->chip->mask_invert) {
@@ -258,7 +261,7 @@ static int regmap_irq_set_type(struct irq_data *data, unsigned int type)
 	const struct regmap_irq_type *t = &irq_data->type;
 
 	if ((t->types_supported & type) != type)
-		return -ENOTSUPP;
+		return 0;
 
 	reg = t->type_reg_offset / map->reg_stride;
 
@@ -588,6 +591,9 @@ int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 	/* Mask all the interrupts by default */
 	for (i = 0; i < chip->num_regs; i++) {
 		d->mask_buf[i] = d->mask_buf_def[i];
+		if (!chip->mask_base)
+			continue;
+
 		reg = chip->mask_base +
 			(i * map->reg_stride * d->irq_reg_stride);
 		if (chip->mask_invert)