regulator: sy8824x: Enable REGCACHE_FLAT

Enable regmap cache to reduce i2c transactions and corresponding
interrupts if regulator is accessed frequently. Since the register map
is small -- there's only one register in sy8824c and sy8824e, there
are only two registers in sy20276 and sy20278, so we use a FLAT regmap
cache.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Link: https://lore.kernel.org/r/20210803165043.042ec24d@xhacker.debian
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/sy8824x.c

@@ -25,6 +25,7 @@ struct sy8824_config {
 	unsigned int vsel_min;
 	unsigned int vsel_step;
 	unsigned int vsel_count;
+	const struct regmap_config *config;
 };
 
 struct sy8824_device_info {
@@ -110,6 +111,15 @@ static int sy8824_regulator_register(struct sy8824_device_info *di,
 static const struct regmap_config sy8824_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
+	.num_reg_defaults_raw = 1,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static const struct regmap_config sy20276_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.num_reg_defaults_raw = 2,
+	.cache_type = REGCACHE_FLAT,
 };
 
 static int sy8824_i2c_probe(struct i2c_client *client)
@@ -134,7 +144,7 @@ static int sy8824_i2c_probe(struct i2c_client *client)
 	di->dev = dev;
 	di->cfg = of_device_get_match_data(dev);
 
-	regmap = devm_regmap_init_i2c(client, &sy8824_regmap_config);
+	regmap = devm_regmap_init_i2c(client, di->cfg->config);
 	if (IS_ERR(regmap)) {
 		dev_err(dev, "Failed to allocate regmap!\n");
 		return PTR_ERR(regmap);
@@ -160,6 +170,7 @@ static const struct sy8824_config sy8824c_cfg = {
 	.vsel_min = 762500,
 	.vsel_step = 12500,
 	.vsel_count = 64,
+	.config = &sy8824_regmap_config,
 };
 
 static const struct sy8824_config sy8824e_cfg = {
@@ -169,6 +180,7 @@ static const struct sy8824_config sy8824e_cfg = {
 	.vsel_min = 700000,
 	.vsel_step = 12500,
 	.vsel_count = 64,
+	.config = &sy8824_regmap_config,
 };
 
 static const struct sy8824_config sy20276_cfg = {
@@ -178,6 +190,7 @@ static const struct sy8824_config sy20276_cfg = {
 	.vsel_min = 600000,
 	.vsel_step = 10000,
 	.vsel_count = 128,
+	.config = &sy20276_regmap_config,
 };
 
 static const struct sy8824_config sy20278_cfg = {
@@ -187,6 +200,7 @@ static const struct sy8824_config sy20278_cfg = {
 	.vsel_min = 762500,
 	.vsel_step = 12500,
 	.vsel_count = 64,
+	.config = &sy20276_regmap_config,
 };
 
 static const struct of_device_id sy8824_dt_ids[] = {