From 5343527bbfab3f71f64d8ba5d51ce12dec8d82d0 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Sun, 6 Jan 2013 11:10:35 +0100 Subject: Power: gpio-poweroff: Fix documentation and gpio_is_valid Improve the documentation to clarify level vs edge triggered power off. Improve the comments for level vs edge triggered power off. Make use of gpio_is_valid(). Reported-by: Stephen Warren Signed-off-by: Andrew Lunn Signed-off-by: Jason Cooper --- drivers/power/reset/gpio-poweroff.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) (limited to 'drivers/power') diff --git a/drivers/power/reset/gpio-poweroff.c b/drivers/power/reset/gpio-poweroff.c index 0491e5335d02..adc943b3fc3f 100644 --- a/drivers/power/reset/gpio-poweroff.c +++ b/drivers/power/reset/gpio-poweroff.c @@ -29,15 +29,16 @@ static int gpio_active_low; static void gpio_poweroff_do_poweroff(void) { - BUG_ON(gpio_num == -1); + BUG_ON(!gpio_is_valid(gpio_num)); - /* drive it active */ + /* drive it active, also inactive->active edge */ gpio_direction_output(gpio_num, !gpio_active_low); mdelay(100); - /* rising edge or drive inactive */ + /* drive inactive, also active->inactive edge */ gpio_set_value(gpio_num, gpio_active_low); mdelay(100); - /* falling edge */ + + /* drive it active, also inactive->active edge */ gpio_set_value(gpio_num, !gpio_active_low); /* give it some time */ @@ -60,15 +61,12 @@ static int __devinit gpio_poweroff_probe(struct platform_device *pdev) } gpio_num = of_get_gpio_flags(pdev->dev.of_node, 0, &flags); - if (gpio_num < 0) { - pr_err("%s: Could not get GPIO configuration: %d", - __func__, gpio_num); - return -ENODEV; - } + if (!gpio_is_valid(gpio_num)) + return gpio_num; + gpio_active_low = flags & OF_GPIO_ACTIVE_LOW; - if (of_get_property(pdev->dev.of_node, "input", NULL)) - input = true; + input = of_property_read_bool(pdev->dev.of_node, "input"); ret = gpio_request(gpio_num, "poweroff-gpio"); if (ret) { @@ -98,8 +96,7 @@ err: static int __devexit gpio_poweroff_remove(struct platform_device *pdev) { - if (gpio_num != -1) - gpio_free(gpio_num); + gpio_free(gpio_num); if (pm_power_off == &gpio_poweroff_do_poweroff) pm_power_off = NULL; @@ -115,15 +112,15 @@ static struct platform_driver gpio_poweroff_driver = { .probe = gpio_poweroff_probe, .remove = __devexit_p(gpio_poweroff_remove), .driver = { - .name = "poweroff-gpio", - .owner = THIS_MODULE, - .of_match_table = of_gpio_poweroff_match, - }, + .name = "poweroff-gpio", + .owner = THIS_MODULE, + .of_match_table = of_gpio_poweroff_match, + }, }; module_platform_driver(gpio_poweroff_driver); MODULE_AUTHOR("Jamie Lentin "); MODULE_DESCRIPTION("GPIO poweroff driver"); -MODULE_LICENSE("GPL"); +MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:poweroff-gpio"); -- cgit v1.2.3