From a416bfa2a6b4e00a7bc69641b8fc2414873a5fd9 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 21 Aug 2013 17:59:24 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/cpm_uart/cpm_uart_core.c | 28 +++++++++++++++++++-- 1 file 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; -- 2.30.2