regmap-irq: Introduce virtual regs to handle more config regs

Add "virtual" registers support to handle any irq configuration
registers in addition to the ones the framework currently supports
(status, mask, unmask, wake, type and ack). These are non-standard
registers that further configure irq type on some devices, so enable the
framework to add a variable number of them.

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Link: https://lore.kernel.org/r/a1787067004b0e11cb960319082764397469215a.1616613838.git.gurus@codeaurora.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Guru Das Srinagesh

drivers/base/regmap/regmap-irq.c

@@ -38,6 +38,7 @@ struct regmap_irq_chip_data {
 	unsigned int *wake_buf;
 	unsigned int *type_buf;
 	unsigned int *type_buf_def;
+	unsigned int **virt_buf;
 
 	unsigned int irq_reg_stride;
 	unsigned int type_reg_stride;
@@ -94,7 +95,7 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 {
 	struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
 	struct regmap *map = d->map;
-	int i, ret;
+	int i, j, ret;
 	u32 reg;
 	u32 unmask_offset;
 	u32 val;
@@ -218,6 +219,20 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 		}
 	}
 
+	if (d->chip->num_virt_regs) {
+		for (i = 0; i < d->chip->num_virt_regs; i++) {
+			for (j = 0; j < d->chip->num_regs; j++) {
+				reg = sub_irq_reg(d, d->chip->virt_reg_base[i],
+						  j);
+				ret = regmap_write(map, reg, d->virt_buf[i][j]);
+				if (ret != 0)
+					dev_err(d->map->dev,
+						"Failed to write virt 0x%x: %d\n",
+						reg, ret);
+			}
+		}
+	}
+
 	if (d->chip->runtime_pm)
 		pm_runtime_put(map->dev);
 
@@ -691,6 +706,24 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			goto err_alloc;
 	}
 
+	if (chip->num_virt_regs) {
+		/*
+		 * Create virt_buf[chip->num_extra_config_regs][chip->num_regs]
+		 */
+		d->virt_buf = kcalloc(chip->num_virt_regs, sizeof(*d->virt_buf),
+				      GFP_KERNEL);
+		if (!d->virt_buf)
+			goto err_alloc;
+
+		for (i = 0; i < chip->num_virt_regs; i++) {
+			d->virt_buf[i] = kcalloc(chip->num_regs,
+						 sizeof(unsigned int),
+						 GFP_KERNEL);
+			if (!d->virt_buf[i])
+				goto err_alloc;
+		}
+	}
+
 	d->irq_chip = regmap_irq_chip;
 	d->irq_chip.name = chip->name;
 	d->irq = irq;
@@ -863,6 +896,9 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 	kfree(d->mask_buf);
 	kfree(d->status_buf);
 	kfree(d->status_reg_buf);
+	for (i = 0; i < chip->num_virt_regs; i++)
+		kfree(d->virt_buf[i]);
+	kfree(d->virt_buf);
 	kfree(d);
 	return ret;
 }

include/linux/regmap.h

@@ -1393,6 +1393,7 @@ struct regmap_irq_sub_irq_map {
  *               Using zero value is possible with @use_ack bit.
  * @wake_base:   Base address for wake enables.  If zero unsupported.
  * @type_base:   Base address for irq type.  If zero unsupported.
+ * @virt_reg_base:   Base addresses for extra config regs.
  * @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.
@@ -1417,6 +1418,8 @@ struct regmap_irq_sub_irq_map {
  *               assigned based on the index in the array of the interrupt.
  * @num_irqs:    Number of descriptors.
  * @num_type_reg:    Number of type registers.
+ * @num_virt_regs:   Number of non-standard irq configuration registers.
+ *		     If zero unsupported.
  * @type_reg_stride: Stride to use for chips where type registers are not
  *			contiguous.
  * @handle_pre_irq:  Driver specific callback to handle interrupt from device
@@ -1444,6 +1447,7 @@ struct regmap_irq_chip {
 	unsigned int ack_base;
 	unsigned int wake_base;
 	unsigned int type_base;
+	unsigned int *virt_reg_base;
 	unsigned int irq_reg_stride;
 	bool mask_writeonly:1;
 	bool init_ack_masked:1;
@@ -1464,6 +1468,7 @@ struct regmap_irq_chip {
 	int num_irqs;
 
 	int num_type_reg;
+	int num_virt_regs;
 	unsigned int type_reg_stride;
 
 	int (*handle_pre_irq)(void *irq_drv_data);