[PATCH 2/2] gpio: pca9570: add slg7xl45106 support

[Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxx>]

slg7xl45106 is a I2C GPO expander.
Add a compatible string for the same. Also update the
driver to write and read from it.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxx>
---
 drivers/gpio/gpio-pca9570.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-pca9570.c b/drivers/gpio/gpio-pca9570.c
index 2735cd6addcf..b4e422b25ea6 100644
--- a/drivers/gpio/gpio-pca9570.c
+++ b/drivers/gpio/gpio-pca9570.c
@@ -15,6 +15,8 @@
 #include <linux/mutex.h>
 #include <linux/property.h>
 
+#define SLG7XL45106_GPO_REG	0xDB
+
 /**
  * struct pca9570 - GPIO driver data
  * @chip: GPIO controller chip
@@ -25,6 +27,7 @@ struct pca9570 {
 	struct gpio_chip chip;
 	struct mutex lock;
 	u8 out;
+	u8 command;
 };
 
 static int pca9570_read(struct pca9570 *gpio, u8 *value)
@@ -32,7 +35,7 @@ static int pca9570_read(struct pca9570 *gpio, u8 *value)
 	struct i2c_client *client = to_i2c_client(gpio->chip.parent);
 	int ret;
 
-	ret = i2c_smbus_read_byte(client);
+	ret = i2c_smbus_read_byte_data(client, gpio->command);
 	if (ret < 0)
 		return ret;
 
@@ -44,6 +47,9 @@ static int pca9570_write(struct pca9570 *gpio, u8 value)
 {
 	struct i2c_client *client = to_i2c_client(gpio->chip.parent);
 
+	if (gpio->command)
+		return i2c_smbus_write_byte_data(client, gpio->command, value);
+
 	return i2c_smbus_write_byte(client, value);
 }
 
@@ -94,6 +100,7 @@ static void pca9570_set(struct gpio_chip *chip, unsigned int offset, int value)
 static int pca9570_probe(struct i2c_client *client)
 {
 	struct pca9570 *gpio;
+	struct device_node *np = client->dev.of_node;
 
 	gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
 	if (!gpio)
@@ -109,6 +116,9 @@ static int pca9570_probe(struct i2c_client *client)
 	gpio->chip.ngpio = (uintptr_t)device_get_match_data(&client->dev);
 	gpio->chip.can_sleep = true;
 
+	if (of_device_is_compatible(np, "dlg,slg7xl45106"))
+		gpio->command = SLG7XL45106_GPO_REG;
+
 	mutex_init(&gpio->lock);
 
 	/* Read the current output level */
@@ -121,12 +131,14 @@ static int pca9570_probe(struct i2c_client *client)
 
 static const struct i2c_device_id pca9570_id_table[] = {
 	{ "pca9570", 4 },
+	{ "slg7xl45106", 8 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(i2c, pca9570_id_table);
 
 static const struct of_device_id pca9570_of_match_table[] = {
 	{ .compatible = "nxp,pca9570", .data = (void *)4 },
+	{ .compatible = "dlg,slg7xl45106", .data = (void *)8 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, pca9570_of_match_table);
-- 
2.17.1