iio: light: veml3235: extend regmap to add cache

The configuration and ID registers are not volatile and are not affected
by read operations (i.e. not precious), making them suitable to be
cached in order to reduce the number of accesses to the device.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://patch.msgid.link/20241224-veml3235_scale-v2-3-2e1286846c77@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: javiercarrascocruz

drivers/iio/light/veml3235.c

@@ -101,12 +101,43 @@ static const struct iio_chan_spec veml3235_channels[] = {
 	},
 };
 
+static const struct regmap_range veml3235_readable_ranges[] = {
+	regmap_reg_range(VEML3235_REG_CONF, VEML3235_REG_ID),
+};
+
+static const struct regmap_access_table veml3235_readable_table = {
+	.yes_ranges = veml3235_readable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml3235_readable_ranges),
+};
+
+static const struct regmap_range veml3235_writable_ranges[] = {
+	regmap_reg_range(VEML3235_REG_CONF, VEML3235_REG_CONF),
+};
+
+static const struct regmap_access_table veml3235_writable_table = {
+	.yes_ranges = veml3235_writable_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml3235_writable_ranges),
+};
+
+static const struct regmap_range veml3235_volatile_ranges[] = {
+	regmap_reg_range(VEML3235_REG_WH_DATA, VEML3235_REG_ALS_DATA),
+};
+
+static const struct regmap_access_table veml3235_volatile_table = {
+	.yes_ranges = veml3235_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(veml3235_volatile_ranges),
+};
+
 static const struct regmap_config veml3235_regmap_config = {
 	.name = "veml3235_regmap",
 	.reg_bits = 8,
 	.val_bits = 16,
 	.max_register = VEML3235_REG_ID,
 	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+	.rd_table = &veml3235_readable_table,
+	.wr_table = &veml3235_writable_table,
+	.volatile_table = &veml3235_volatile_table,
+	.cache_type = REGCACHE_RBTREE,
 };
 
 static int veml3235_get_it(struct veml3235_data *data, int *val, int *val2)