gpio: pca953x: Fix NBANK calculation for PCA9536

[ Upstream commit a246b8198f776a16d1d3a3bbfc2d437bad766b29 ]

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@vger.kernel.org
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 16f7c4f2d8c8d14e1f3bd777df3d306265c572a5..6e2720ea7d45eef77fb67910bc92daf60a510940 100644 (file)
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -76,7 +76,7 @@ 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;