[PATCH 4/5] gpio: tps68470: Add i2c daisy chain support

[Antti Laakso <antti.laakso@linux.intel.com>]

The tps68470 daisy chain make use of gpio 1 and 2. When in use, these
gpios must be configured as inputs without pull-up.

Signed-off-by: Antti Laakso <antti.laakso@linux.intel.com>
---
 drivers/gpio/gpio-tps68470.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-tps68470.c b/drivers/gpio/gpio-tps68470.c
index d4fbdf90e190..729ad8e397fc 100644
--- a/drivers/gpio/gpio-tps68470.c
+++ b/drivers/gpio/gpio-tps68470.c
@@ -14,6 +14,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/mfd/tps68470.h>
 #include <linux/module.h>
+#include <linux/platform_data/tps68470.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
@@ -120,6 +121,17 @@ static int tps68470_gpio_input(struct gpio_chip *gc, unsigned int offset)
 				   TPS68470_GPIO_MODE_MASK, 0x00);
 }
 
+static int tps68470_enable_i2c_daisy_chain(struct gpio_chip *gc)
+{
+	int ret;
+
+	ret = tps68470_gpio_input(gc, 1);
+	if (ret)
+		return ret;
+
+	return tps68470_gpio_input(gc, 2);
+}
+
 static const char *tps68470_names[TPS68470_N_GPIO] = {
 	"gpio.0", "gpio.1", "gpio.2", "gpio.3",
 	"gpio.4", "gpio.5", "gpio.6",
@@ -129,6 +141,8 @@ static const char *tps68470_names[TPS68470_N_GPIO] = {
 static int tps68470_gpio_probe(struct platform_device *pdev)
 {
 	struct tps68470_gpio_data *tps68470_gpio;
+	struct tps68470_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	int ret = 0;
 
 	tps68470_gpio = devm_kzalloc(&pdev->dev, sizeof(*tps68470_gpio),
 				     GFP_KERNEL);
@@ -149,7 +163,14 @@ static int tps68470_gpio_probe(struct platform_device *pdev)
 	tps68470_gpio->gc.base = -1;
 	tps68470_gpio->gc.parent = &pdev->dev;
 
-	return devm_gpiochip_add_data(&pdev->dev, &tps68470_gpio->gc, tps68470_gpio);
+	ret = devm_gpiochip_add_data(&pdev->dev, &tps68470_gpio->gc, tps68470_gpio);
+	if (ret)
+		return ret;
+
+	if (pdata && pdata->daisy_chain_enable)
+		ret = tps68470_enable_i2c_daisy_chain(&tps68470_gpio->gc);
+
+	return ret;
 }
 
 static struct platform_driver tps68470_gpio_driver = {
-- 
2.53.0