From 7bfa0781406f9df6cb20ce5134faa19d34cb4e18 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 19 Mar 2015 16:55:22 +0100 Subject: [PATCH] greybus: gpio: refuse to set value of input pins Add warning and refuse to set output value for pin configured as input, as the result of such an operation is undefined. Remove incorrect todo-comment suggesting that the driver could implicitly switch direction as part of the call. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/gpio.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/staging/greybus/gpio.c b/drivers/staging/greybus/gpio.c index b18fb7e12a5b..7e51840cd262 100644 --- a/drivers/staging/greybus/gpio.c +++ b/drivers/staging/greybus/gpio.c @@ -273,14 +273,18 @@ static void gb_gpio_set_value_operation(struct gb_gpio_controller *ggc, struct gb_gpio_set_value_request request; int ret; + if (ggc->lines[which].direction == 1) { + dev_warn(ggc->chip.dev, + "refusing to set value of input gpio %u\n", which); + return; + } + request.which = which; request.value = value_high ? 1 : 0; ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_VALUE, &request, sizeof(request), NULL, 0); - if (!ret) { - /* XXX should this set direction to out? */ + if (!ret) ggc->lines[which].value = request.value; - } } static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc, -- 2.11.0