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 <[email protected]> diff -ur linux-3.8.13/drivers/tty/serial/cpm_uart/cpm_uart_core.c linux/drivers/tty/serial/cpm_uart/cpm_uart_core.c --- linux-3.8.13/drivers/tty/serial/cpm_uart/cpm_uart_core.c 2013-08-21 05:34:03.000000000 +0200 +++ linux/drivers/tty/serial/cpm_uart/cpm_uart_core.c 2013-08-21 05:30:04.000000000 +0200 @@ -1213,8 +1213,32 @@ 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
