On Thu, Jun 06, 2013 at 04:31:10AM -0700, Guenter Roeck wrote: > On Thu, Jun 06, 2013 at 12:51:03PM +0200, Johannes Thumshirn wrote: > > On Mon, Jun 03, 2013 at 11:50:26AM +0200, Johannes Thumshirn wrote: > > > On Fri, May 31, 2013 at 09:15:23PM -0700, Guenter Roeck wrote: > > > > On Fri, May 31, 2013 at 02:55:19PM +0200, Johannes Thumshirn wrote: > > > > > Hi Guenther, > > > > > On Fri, May 31, 2013 at 04:40:37AM -0700, Guenter Roeck wrote: > > > > > > > +#define GPIO_WD_ENAB 169 > > > > > > > +#define GPIO_WD_FAST 170 > > > > > > > +#define GPIO_WD_TRIG 171 > > > > > > > + > > > > > > > +#define GPIO_RST_CAUSE_BASE 166 > > > > > > > + > > > > > > > > > > > > I think I asked that before ... as you are supporting devicetree, gpio pins > > > > > > should really be provided through devicetree properties and not be hardcoded. > > > > > > > > > > > Yes you did and I didn't come up with a solution to this problem yet. I understand > > > > > and agree to your concerns but I'm lacking example code/documentation for it, maybe > > > > > you can point me to an example on that and then I'll update my code accordingly. > > > > > > > > > > > > > Have a look at Documentation/devicetree/bindings/gpio/gpio-fan.txt and > > > > drivers/hwmon/gpio-fan.c. > > > > > > Thanks a lot, this really helped me out. Updated patch is comming today > > > including the bindings document Arnd Bergmann requested. I only need to rebase > > > the sysfs patch on top of that changes. > > > > > > Regards, > > > Johannes > > > > Regarding the sysfs patch, I have a funny effect in my (rebased) sysfs code. > > > > Given the following code: > > > > +static ssize_t rebootcause_show(struct device *dev, > > + struct device_attribute *attr, > > + char *buf) > > +{ > > + struct a21_wdt_drv *drv = dev_get_drvdata(dev); > > + unsigned int reset = 0; > > + > > + if (!drv) > > + return -EIO; > > + > > + reset = a21_wdt_get_bootstatus(drv); > > + > > + return sprintf(buf, "%s\n", reset_causes[reset]); > > +} > > +static DEVICE_ATTR(rebootcause, S_IRUGO, rebootcause_show, NULL); > > > > I actually need the check for if (!drv) to prevent an OOPS, as > > dev_get_drvdata(dev) returns NULL., though it is set at the end of my probe > > function via: > > > > [...] > > + ret = watchdog_register_device(&a21_wdt); > > + if (ret) { > > + dev_err(&pdev->dev, "Cannot register watchdog device\n"); > > + goto err_register_wd; > > + } > > + > > + dev_set_drvdata(&pdev->dev, drv); > > + > > + return 0; > > [...] > > > > The watchdog driver itself is working without any troubles. > > > > Some advice here would be worth its weight in gold. > > > It has to be set before the attribute is created. Are you doing that ? Also, is > 'dev' the same device pointer (ie is the 'dev' in your function the same as > &pdev->dev) ? > > Guenter Hi Guenter, Thanks for the quick reply. Indeed 'dev' in my function is a struct watchdog_device's dev (for device_create_file) and not &pdev->dev. Which in turn are not the same. A call to dev_set_drvdata(a21_wdt.dev, drv); solved the NULL pointer access. So last question, is it save to set the drvdata of a dev inside the struct watchdog_device or do I break something vital that way? Thanks a lot, Johannes -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html