regmap: add support for non contiguous status to regmap-irq

In some chips the IRQ status registers are not contiguous in the register
map but spaced at even spaces. This is an easy case to handle with minor
changes. It is assume for this purpose that the stride for status is
equal to the stride for mask/ack registers as well.

Signed-off-by: Graeme Gregory <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/base/regmap/regmap-irq.c

···
 	int irq_base;
 	struct irq_domain *domain;
 
-	void *status_reg_buf;
 	unsigned int *status_buf;
 	unsigned int *mask_buf;
 	unsigned int *mask_buf_def;
+
+	unsigned int irq_reg_stride;
 };
 
 static inline const
···
 	 */
 	for (i = 0; i < d->chip->num_regs; i++) {
 		ret = regmap_update_bits(d->map, d->chip->mask_base +
-						(i * map->reg_stride),
+						(i * map->reg_stride *
+						d->irq_reg_stride),
 					 d->mask_buf_def[i], d->mask_buf[i]);
 		if (ret != 0)
 			dev_err(d->map->dev, "Failed to sync masks in %x\n",
···
 	struct regmap_irq_chip *chip = data->chip;
 	struct regmap *map = data->map;
 	int ret, i;
-	u8 *buf8 = data->status_reg_buf;
-	u16 *buf16 = data->status_reg_buf;
-	u32 *buf32 = data->status_reg_buf;
 	bool handled = false;
-
-	ret = regmap_bulk_read(map, chip->status_base, data->status_reg_buf,
-			       chip->num_regs);
-	if (ret != 0) {
-		dev_err(map->dev, "Failed to read IRQ status: %d\n", ret);
-		return IRQ_NONE;
-	}
 
 	/*
 	 * Ignore masked IRQs and ack if we need to; we ack early so
···
 	 * doing a write per register.
 	 */
 	for (i = 0; i < data->chip->num_regs; i++) {
-		switch (map->format.val_bytes) {
-		case 1:
-			data->status_buf[i] = buf8[i];
-			break;
-		case 2:
-			data->status_buf[i] = buf16[i];
-			break;
-		case 4:
-			data->status_buf[i] = buf32[i];
-			break;
-		default:
-			BUG();
+		ret = regmap_read(map, chip->mask_base + (i * map->reg_stride
+				   * data->irq_reg_stride),
+				   &data->status_buf[i]);
+
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to read IRQ status: %d\n",
+					ret);
 			return IRQ_NONE;
 		}
 
···
 
 		if (data->status_buf[i] && chip->ack_base) {
 			ret = regmap_write(map, chip->ack_base +
-						(i * map->reg_stride),
+						(i * map->reg_stride *
+						data->irq_reg_stride),
 					   data->status_buf[i]);
 			if (ret != 0)
 				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
···
 	if (!d->status_buf)
 		goto err_alloc;
 
-	d->status_reg_buf = kzalloc(map->format.val_bytes * chip->num_regs,
-				    GFP_KERNEL);
-	if (!d->status_reg_buf)
-		goto err_alloc;
-
 	d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
 			      GFP_KERNEL);
 	if (!d->mask_buf)
···
 	d->map = map;
 	d->chip = chip;
 	d->irq_base = irq_base;
+
+	if (chip->irq_reg_stride)
+		d->irq_reg_stride = chip->irq_reg_stride;
+	else
+		d->irq_reg_stride = 1;
+
 	mutex_init(&d->lock);
 
 	for (i = 0; i < chip->num_irqs; i++)
···
 	/* Mask all the interrupts by default */
 	for (i = 0; i < chip->num_regs; i++) {
 		d->mask_buf[i] = d->mask_buf_def[i];
-		ret = regmap_write(map, chip->mask_base + (i * map->reg_stride),
+		ret = regmap_write(map, chip->mask_base + (i * map->reg_stride
+				   * d->irq_reg_stride),
 				   d->mask_buf[i]);
 		if (ret != 0) {
 			dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
···
 err_alloc:
 	kfree(d->mask_buf_def);
 	kfree(d->mask_buf);
-	kfree(d->status_reg_buf);
 	kfree(d->status_buf);
 	kfree(d);
 	return ret;
···
 	/* We should unmap the domain but... */
 	kfree(d->mask_buf_def);
 	kfree(d->mask_buf);
-	kfree(d->status_reg_buf);
 	kfree(d->status_buf);
 	kfree(d);
 }

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.
+ * @irq_reg_stride:  Stride to use for chips where registers are not contiguous.
  *
  * @num_regs:    Number of registers in each control bank.
  * @irqs:        Descriptors for individual IRQs.  Interrupt numbers are
···
 	unsigned int status_base;
 	unsigned int mask_base;
 	unsigned int ack_base;
+	unsigned int irq_reg_stride;
 
 	int num_regs;