Re: cdev to pdev

[Jim Cromie <jim.cromie@xxxxxxxxx>]

Greg KH wrote:
> I wrote
> > so, wheres my device ?
> >     
>
> Depends on what your driver is, and where it stores it.
>
>   
> > dont I automatically get one, perhaps under the covers ?
> >     
>
> Depends on what type of driver you are.  If you are an i2c driver, you
> get one.  A PCI driver, you get one.  A USB driver, you get one.  A
> platform driver, well, you might be on your own, you have to create
> yours, using the platform api.
>
>   
ok - got something that works.

+
+       pdev = platform_device_register_simple(DRVNAME, 0, NULL, 0);
+       if (!pdev) {
+               printk(KERN_ERR NAME "Error %d on minor %d", rc, i);
+       } else {
+               dev_err(pdev, "devinfo works! %d devs\n", i);
+       }
       return 0;               /* succeed */



So, style question.  In scx200_gpio_init, Ive got to
   devices = kzalloc
   register-chrdev-region
   platform-device-register

presuming that I should be calling all 3, is there any reason to prefer 
1 order vs another ?
most-likely to fail 1st ?   and which is that ?




> > couldnt the others be also (if later).
> >
> > I also found this:
> > **Subject: Driver model ISA bus**
> > http://marc.theaimsgroup.com/?l=linux-kernel&m=114678055902797&w=2
> > It looks interesting - anything that simplifies stuff is -
> > but alas - theres no empty-isa-driver.c for me to start from.
> >     
>
> It's getting there, hasn't made it into any kernel trees yet...
>
> thanks,
>
> greg k-h
>
>   


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