[PATCH v2 2/4] media: i2c: ds90ub953: Add back channel GPIO support

[Guoniu Zhou <guoniu.zhou@nxp.com>]

The ds90ub953 supports GPIO0 through GPIO3. When enabled as an output,
each GPIO pin can be programed to output remote data coming from the
compatible deserializer using the register LOCAL_GPIO_DATA[7:4] field.

Add third cell for GPIO controller to select output source.

Signed-off-by: Guoniu Zhou <guoniu.zhou@nxp.com>
---
 drivers/media/i2c/ds90ub953.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/media/i2c/ds90ub953.c b/drivers/media/i2c/ds90ub953.c
index e3fc9d66970a762d284955f14db48d7105b4b8c4..274972cd21f9f0facd5098b724c0d6c661ce95c2 100644
--- a/drivers/media/i2c/ds90ub953.c
+++ b/drivers/media/i2c/ds90ub953.c
@@ -71,6 +71,7 @@ struct ub953_data {
 	bool			non_continous_clk;
 
 	struct gpio_chip	gpio_chip;
+	bool			gpio_rmten[UB953_NUM_GPIOS];
 
 	struct v4l2_subdev	sd;
 	struct media_pad	pads[2];
@@ -288,13 +289,17 @@ static int ub953_gpio_direction_out(struct gpio_chip *gc, unsigned int offset,
 				    int value)
 {
 	struct ub953_data *priv = gpiochip_get_data(gc);
+	unsigned int val;
 	int ret;
 
-	ret = regmap_update_bits(priv->regmap, UB953_REG_LOCAL_GPIO_DATA,
-				 UB953_REG_LOCAL_GPIO_DATA_GPIO_OUT_SRC(offset),
-				 value ? UB953_REG_LOCAL_GPIO_DATA_GPIO_OUT_SRC(offset) :
-					 0);
+	val = priv->gpio_rmten[offset]
+	    ? UB953_REG_LOCAL_GPIO_DATA_GPIO_RMTEN(offset)
+	    : value ? UB953_REG_LOCAL_GPIO_DATA_GPIO_OUT_SRC(offset) : 0;
 
+	ret = regmap_update_bits(priv->regmap, UB953_REG_LOCAL_GPIO_DATA,
+				 UB953_REG_LOCAL_GPIO_DATA_GPIO_OUT_SRC(offset) |
+					UB953_REG_LOCAL_GPIO_DATA_GPIO_RMTEN(offset),
+				 val);
 	if (ret)
 		return ret;
 
@@ -320,6 +325,12 @@ static int ub953_gpio_get(struct gpio_chip *gc, unsigned int offset)
 static int ub953_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
 {
 	struct ub953_data *priv = gpiochip_get_data(gc);
+	struct device *dev = &priv->client->dev;
+
+	if (priv->gpio_rmten[offset]) {
+		dev_err(dev, "GPIO%u be programed to output remote data\n", offset);
+		return -EINVAL;
+	}
 
 	return regmap_update_bits(priv->regmap, UB953_REG_LOCAL_GPIO_DATA,
 				  UB953_REG_LOCAL_GPIO_DATA_GPIO_OUT_SRC(offset),
@@ -330,10 +341,19 @@ static int ub953_gpio_of_xlate(struct gpio_chip *gc,
 			       const struct of_phandle_args *gpiospec,
 			       u32 *flags)
 {
+	struct ub953_data *priv = gpiochip_get_data(gc);
+	u32 line;
+
+	line = gpiospec->args[0];
+	if (line >= UB953_NUM_GPIOS)
+		return -EINVAL;
+
+	priv->gpio_rmten[line] = gpiospec->args[2] ? true : false;
+
 	if (flags)
 		*flags = gpiospec->args[1];
 
-	return gpiospec->args[0];
+	return line;
 }
 
 static int ub953_gpiochip_probe(struct ub953_data *priv)
@@ -363,7 +383,7 @@ static int ub953_gpiochip_probe(struct ub953_data *priv)
 	gc->get = ub953_gpio_get;
 	gc->set = ub953_gpio_set;
 	gc->of_xlate = ub953_gpio_of_xlate;
-	gc->of_gpio_n_cells = 2;
+	gc->of_gpio_n_cells = 3;
 
 	ret = gpiochip_add_data(gc, priv);
 	if (ret) {

-- 
2.34.1