This patch fixes a backward compatibility issue, when boards use the
old style GPIO suffix "-gpio" instead of the new "-gpios". This
potential problem has been introduced by commit d99482673f95 ("serial:
mctrl_gpio: Check if GPIO property exisits before requesting it").
This patch now fixes this issue by iterating over all supported GPIO
suffixes by using the newly introduced for_each_gpio_suffix() helper.
Also, the string buffer is now allocated on the stack to avoid the
problem of allocation in a loop and its potential failure.
Signed-off-by: Stefan Roese <sr@xxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_mctrl_gpio.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
index 2b400189be91..d444fdaa280a 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.c
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -15,6 +15,7 @@
#include <linux/property.h>
#include "serial_mctrl_gpio.h"
+#include "../../gpio/gpiolib.h"
struct mctrl_gpios {
struct uart_port *port;
@@ -117,17 +118,24 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
for (i = 0; i < UART_GPIO_MAX; i++) {
enum gpiod_flags flags;
- char *gpio_str;
+ const char *suffix;
+ char gpio_str[32]; /* 32 is max size of property name */
bool present;
+ int k;
+
+ /*
+ * Check if GPIO property exists and continue if not. Iterate
+ * over all supported GPIO suffixes (foo-gpios vs. foo-gpio).
+ */
+ for_each_gpio_suffix(k, suffix) {
+ snprintf(gpio_str, sizeof(gpio_str), "%s-%s",
+ mctrl_gpios_desc[i].name, suffix);
+
+ present = device_property_present(dev, gpio_str);
+ if (present)
+ break;
+ }
- /* Check if GPIO property exists and continue if not */
- gpio_str = kasprintf(GFP_KERNEL, "%s-gpios",
- mctrl_gpios_desc[i].name);
- if (!gpio_str)
- continue;
-
- present = device_property_present(dev, gpio_str);
- kfree(gpio_str);
if (!present)
continue;
--
2.22.0
