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authorChristophe Leroy <christophe.leroy@c-s.fr>2013-08-21 17:59:24 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-27 22:06:22 -0700
commita416bfa2a6b4e00a7bc69641b8fc2414873a5fd9 (patch)
treea4e94f9f671677209492f08ba13c1033a1ca573b /drivers/tty
parentb60dfbae4151fe8c8a59724c43f5f3f66d51695f (diff)
downloadlinux-a416bfa2a6b4e00a7bc69641b8fc2414873a5fd9.tar.bz2
tty: serial: cpm_uart: Adding proper request of GPIO used by cpm_uart driver
cpm_uart serial driver uses GPIO for control signals. In order to be used properly, GPIOs have to be reserved. Comment in gpiolib.c considers illegal the use of GPIOs without requesting them. In addition, the direction of the GPIO has to be set properly. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/cpm_uart/cpm_uart_core.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
index f7672cae5321..1a535f70dc41 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -1213,8 +1213,32 @@ static int cpm_uart_init_port(struct device_node *np,
goto out_pram;
}
- for (i = 0; i < NUM_GPIOS; i++)
- pinfo->gpios[i] = of_get_gpio(np, i);
+ for (i = 0; i < NUM_GPIOS; i++) {
+ int gpio;
+
+ pinfo->gpios[i] = -1;
+
+ gpio = of_get_gpio(np, i);
+
+ if (gpio_is_valid(gpio)) {
+ ret = gpio_request(gpio, "cpm_uart");
+ if (ret) {
+ pr_err("can't request gpio #%d: %d\n", i, ret);
+ continue;
+ }
+ if (i == GPIO_RTS || i == GPIO_DTR)
+ ret = gpio_direction_output(gpio, 0);
+ else
+ ret = gpio_direction_input(gpio);
+ if (ret) {
+ pr_err("can't set direction for gpio #%d: %d\n",
+ i, ret);
+ gpio_free(gpio);
+ continue;
+ }
+ pinfo->gpios[i] = gpio;
+ }
+ }
#ifdef CONFIG_PPC_EARLY_DEBUG_CPM
udbg_putc = NULL;