greybus: gpio: fix error handling

Make sure to propagate any errors detected up the call chain.

This specifically means that we will detect failed connection init,
something which is now handled more gracefully by greybus core.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/staging/greybus/gpio.c

@@ -175,7 +175,7 @@ static int gb_gpio_activate_operation(struct gb_gpio_controller *ggc, u8 which)
 	return ret;
 }
 
-static int gb_gpio_deactivate_operation(struct gb_gpio_controller *ggc,
+static void gb_gpio_deactivate_operation(struct gb_gpio_controller *ggc,
 					u8 which)
 {
 	struct gb_gpio_deactivate_request request;
@@ -186,7 +186,6 @@ static int gb_gpio_deactivate_operation(struct gb_gpio_controller *ggc,
 				 &request, sizeof(request), NULL, 0);
 	if (!ret)
 		ggc->lines[which].active = false;
-	return ret;
 }
 
 static int gb_gpio_get_direction_operation(struct gb_gpio_controller *ggc,
@@ -264,7 +263,7 @@ static int gb_gpio_get_value_operation(struct gb_gpio_controller *ggc,
 	return 0;
 }
 
-static int gb_gpio_set_value_operation(struct gb_gpio_controller *ggc,
+static void gb_gpio_set_value_operation(struct gb_gpio_controller *ggc,
 					u8 which, bool value_high)
 {
 	struct gb_gpio_set_value_request request;
@@ -278,7 +277,6 @@ static int gb_gpio_set_value_operation(struct gb_gpio_controller *ggc,
 		/* XXX should this set direction to out? */
 		ggc->lines[which].value = request.value;
 	}
-	return ret;
 }
 
 static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc,
@@ -413,22 +411,15 @@ static void gb_gpio_request_recv(u8 type, struct gb_operation *op)
 static int gb_gpio_request(struct gpio_chip *chip, unsigned offset)
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
-	int ret;
 
-	ret = gb_gpio_activate_operation(ggc, (u8)offset);
-	if (ret)
-		;	/* return ret; */
-	return 0;
+	return gb_gpio_activate_operation(ggc, (u8)offset);
 }
 
 static void gb_gpio_free(struct gpio_chip *chip, unsigned offset)
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
-	int ret;
 
-	ret = gb_gpio_deactivate_operation(ggc, (u8)offset);
-	if (ret)
-		;	/* return ret; */
+	gb_gpio_deactivate_operation(ggc, (u8)offset);
 }
 
 static int gb_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
@@ -440,31 +431,24 @@ static int gb_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
 	which = (u8)offset;
 	ret = gb_gpio_get_direction_operation(ggc, which);
 	if (ret)
-		;	/* return ret; */
+		return ret;
+
 	return ggc->lines[which].direction ? 1 : 0;
 }
 
 static int gb_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
-	int ret;
 
-	ret = gb_gpio_direction_in_operation(ggc, (u8)offset);
-	if (ret)
-		;	/* return ret; */
-	return 0;
+	return gb_gpio_direction_in_operation(ggc, (u8)offset);
 }
 
 static int gb_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 					int value)
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
-	int ret;
 
-	ret = gb_gpio_direction_out_operation(ggc, (u8)offset, !!value);
-	if (ret)
-		;	/* return ret; */
-	return 0;
+	return gb_gpio_direction_out_operation(ggc, (u8)offset, !!value);
 }
 
 static int gb_gpio_get(struct gpio_chip *chip, unsigned offset)
@@ -477,17 +461,15 @@ static int gb_gpio_get(struct gpio_chip *chip, unsigned offset)
 	ret = gb_gpio_get_value_operation(ggc, which);
 	if (ret)
 		return ret;
+
 	return ggc->lines[which].value;
 }
 
 static void gb_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
-	int ret;
 
-	ret = gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
-	if (ret)
-		;	/* return ret; */
+	gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
 }
 
 static int gb_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
@@ -495,16 +477,12 @@ static int gb_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
 {
 	struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
 	u16 usec;
-	int ret;
 
 	if (debounce > U16_MAX)
 		return -EINVAL;
 	usec = (u16)debounce;
-	ret = gb_gpio_set_debounce_operation(ggc, (u8)offset, usec);
-	if (ret)
-		;	/* return ret; */
 
-	return 0;	/* XXX */
+	return gb_gpio_set_debounce_operation(ggc, (u8)offset, usec);
 }
 
 static void gb_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
@@ -521,12 +499,13 @@ static int gb_gpio_controller_setup(struct gb_gpio_controller *ggc)
 	/* First thing we need to do is check the version */
 	ret = get_version(ggc);
 	if (ret)
-		;	/* return ret; */
+		return ret;
 
 	/* Now find out how many lines there are */
 	ret = gb_gpio_line_count_operation(ggc);
 	if (ret)
-		;	/* return ret; */
+		return ret;
+
 	line_count = (u32)ggc->line_max + 1;
 	size = line_count * sizeof(*ggc->lines);
 	ggc->lines = kzalloc(size, GFP_KERNEL);