[PATCH 4.4 015/138] gpio: pca953x: Fix NBANK calculation for PCA9536

Greg Kroah-Hartman
2016-08-18T14:02:02Z

From: Vignesh R <vigneshr@ti.com>

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().

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpio/gpio-pca953x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -86,7 +86,7 @@ MODULE_DEVICE_TABLE(acpi, pca953x_acpi_i
#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;