I changed it: MUX_CFG(DA850, GPIO_LED0, 18, 12, 15, 8, false)
-- Nicolas Luna On Wed, Jun 30, 2010 at 1:29 PM, Caglar Akyuz <[email protected]> wrote: > On Wednesday 30 June 2010 08:06:38 pm Nicolas Luna wrote: > > Hi, > > > > With the code below in da850-board-evm.c, I can turn on my LED connected > to > > the gpio. > > > > #define DA850_LED0_GPIO GPIO_TO_PIN(8, 14) > > > > status = gpio_request(DA850_LED0_GPIO, "led0gpio"); > > if (status < 0) { > > return status; > > } > > gpio_direction_output(DA850_LED0_GPIO, 0); > > gpio_set_value(DA850_LED0_GPIO, 0); > > > > If I comment this code in the kernel initialization and I try what you > > proposed, I do not get the same result. (142 comes from 16*8+14) > > > > # echo 142 > /sys/class/gpio/export > > > > # ls /sys/class/gpio > > export gpio142 gpiochip128 gpiochip64 unexport gpiochip0 gpiochip32 > > gpiochip96 > > > > # cat /sys/class/gpio/gpio142/value > > 1 > > > > # echo 1 > /sys/class/gpio/gpio142/direction > > # echo 0 > /sys/class/gpio/gpio142/value > > # cat /sys/class/gpio/gpio142/value > > 1 > > > > The output is always to 1, in fact the gpio is not in output, it is still > > in tri-state. CONFIG_GPIO_SYSFS is enabled. > > > > Do you have any idea? > > > > Maybe you have a pinmux specific configuration in your board file as well? > > Regards, > Caglar > > > Thanks. > > > > Regards, > > > > Nicolas > > > > > > > > On Wed, Jun 30, 2010 at 3:28 AM, Christophe Aeschlimann < > > > > [email protected]> wrote: > > > Hi, > > > > > > On 30.06.2010 04:09, Jon Povey wrote: > > >> Nicolas Luna wrote: > > >>> Hi, > > >>> > > >>> I wonder what would be the easiest way to control GPIO in userspace. > > >>> I read the documentation gpio.txt but I'm not sure what I should use > > >>> (Control interfaces?, GPIO controllers?) and how to implement it. > > >>> > > >>> Is there more explication about int gpio_export_link(struct device > > >>> *dev, const char *name, unsigned gpio) because I think it could be > > >>> the key. > > >>> > > >>> Will I need to write my own module and communicate with it?. > > >> > > >> You don't need to write a module. You can access GPIOs from a shell > > >> script: > > > > > > To be able to do so you must configure your kernel with the following > > > option enabled : > > > > > > CONFIG_GPIO_SYSFS > > > > > > > > > echo $GPIO_NUMBER> /sys/class/gpio/export > > > > > >> creates a directory /sys/class/gpio/gpio$GPIO_NUMBER, e.g. 8. > > >> (That will fail if something else like a driver has requested that > gpio > > >> already). > > >> > > >> cat /sys/class/gpio/gpio8/value > > >> > > >> gets the value 0/1 > > >> > > >> echo 1> /sys/class/gpio/gpio8/direction > > >> > > >> sets it to output (iirc) > > >> > > >> echo 1> /sys/class/gpio/gpio8/value > > >> > > >> now sets the output value. > > >> > > >> echo 8> /sys/class/gpio/unexport > > >> > > >> to release it when you are finished. > > >> > > >> gpio_export_link() is for when you claim a gpio for use in the kernel > > >> but also want to export one of the above kind of sysfs entries. > > >> > > >> -- > > >> Jon Povey > > >> [email protected] > > >> > > >> Racelogic is a limited company registered in England. Registered > number > > >> 2743719 . > > >> Registered Office Unit 10, Swan Business Centre, Osier Way, > Buckingham, > > >> Bucks, MK18 1TB . > > >> > > >> The information contained in this electronic mail transmission is > > >> intended by Racelogic Ltd for the use of the named individual or > entity > > >> to which it is directed and may contain information that is > confidential > > >> or privileged. If you have received this electronic mail transmission > in > > >> error, please delete it from your system without copying or forwarding > > >> it, and notify the sender of the error by reply email so that the > > >> sender's address records can be corrected. The views expressed by the > > >> sender of this communication do not necessarily represent those of > > >> Racelogic Ltd. Please note that Racelogic reserves the right to > monitor > > >> e-mail communications passing through its network > > > > > > Regards, > > > > > > > > > -- > > > Christophe Aeschlimann > > > > > > Embedded Software Engineer > > > > > > Advanced Communications Networks S.A. > > > > > > Rue du Puits-Godet 8a > > > 2000 Neuchātel, Switzerland > > > > > > Tél. +41 32 724 74 31 > > > > > > [email protected] > > >
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