[PATCH 3.10 159/180] gpio: pca953x: Fix NBANK calculation for PCA9536

[Willy Tarreau]

From: Vignesh R <vigneshr@xxxxxx>

commit a246b8198f776a16d1d3a3bbfc2d437bad766b29 upstream.

NBANK() macro assumes that ngpios is a multiple of 8(BANK_SZ) and
hence results in 0 banks for PCA9536 which has just 4 gpios. This is
wrong as PCA9356 has 1 bank with 4 gpios. This results in uninitialized
PCA953X_INVERT register. Fix this by using DIV_ROUND_UP macro in
NBANK().

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vignesh R <vigneshr@xxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
 drivers/gpio/gpio-pca953x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 426c51d..ac11e45 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -75,7 +75,7 @@ MODULE_DEVICE_TABLE(i2c, pca953x_id);
 #define MAX_BANK 5
 #define BANK_SZ 8
 
-#define NBANK(chip) (chip->gpio_chip.ngpio / BANK_SZ)
+#define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)
 
 struct pca953x_chip {
 	unsigned gpio_start;
-- 
2.8.0.rc2.1.gbe9624a