[PATCH linux dev-4.10] leds: pca955x: Fix GPIO request for input setting drain instead of Hi-Z

[Andrew Jeffery]

The prior patch which fixed the problem with output inversion failed to
account for a necessary fix to requesting a pin for input, which is
affected by the open-drain nature of the hardware.

Previously pca955x_gpio_direction_input() called through
pca955x_set_value() to configure the direction, however continuing down
this route lead to a brain-haemorhaging level of necessary inversions.
Instead, remove one layer by calling directly into pca955x_led_set(),
and define PCA955X_GPIO_INPUT to paper over the rest of the confusion.

Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
Tested-by: Matt Spinler <mspinler at linux.vnet.ibm.com>
---
I'll send this upstream shortly. LEDs seem to rebase their branch quite often,
so given the original patch is targeting 4.15 we might be able to get the two
squashed together.

 drivers/leds/leds-pca955x.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index 6dcd2d7cc6a4..78183f90820e 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -61,6 +61,7 @@
 #define PCA955X_LS_BLINK0	0x2	/* Blink at PWM0 rate */
 #define PCA955X_LS_BLINK1	0x3	/* Blink at PWM1 rate */
 
+#define PCA955X_GPIO_INPUT	LED_OFF
 #define PCA955X_GPIO_HIGH	LED_OFF
 #define PCA955X_GPIO_LOW	LED_FULL
 
@@ -358,8 +359,11 @@ static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
 					unsigned int offset)
 {
-	/* To use as input ensure pin is not driven */
-	return pca955x_set_value(gc, offset, 0);
+	struct pca955x *pca955x = gpiochip_get_data(gc);
+	struct pca955x_led *led = &pca955x->leds[offset];
+
+	/* To use as input ensure pin is not driven. */
+	return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
 }
 
 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
-- 
2.11.0