[PATCH] cpukit/libi2c allowed to probe on device init

Sebastian Huber sebastian.huber at embedded-brains.de
Thu Apr 2 06:53:03 UTC 2015


Hello Alexandru-Sever,

in case you use the latest RTEMS version, then I would consider to use 
the new I2C support:

https://docs.rtems.org/doxygen/cpukit/html/group__I2C.html

For example see:

https://git.rtems.org/rtems/tree/cpukit/dev/i2c

https://git.rtems.org/rtems/tree/testsuites/libtests/i2c01

On 02/04/15 08:48, Alexandru-Sever Horin wrote:
> From: Alexandru-Sever Horin <alex.sever.h at gmail.com>
>
> libi2c registration of a device fails if the device initialization fails
> Benefits: allows for device probing on multiple addresses
> ---
>   cpukit/libi2c/libi2c.c | 27 ++++++++++++++++-----------
>   1 file changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/cpukit/libi2c/libi2c.c b/cpukit/libi2c/libi2c.c
> index 233cb68..315a761 100644
> --- a/cpukit/libi2c/libi2c.c
> +++ b/cpukit/libi2c/libi2c.c
> @@ -736,6 +736,16 @@ rtems_libi2c_register_drv (const char *name, rtems_libi2c_drv_t * drvtbl,
>         /* found a free slot; encode slot + 1 ! */
>         minor = ((i + 1) << 13) | RTEMS_LIBI2C_MAKE_MINOR (busno, i2caddr);
>   
> +      /* before registering, try to initialize the device to check it's there */
> +      if (drvtbl->ops->initialization_entry) {
> +        err = drvtbl->ops->initialization_entry (rtems_libi2c_major, minor, 0);
> +        if (err) {
> +          LIBUNLOCK ();
> +          /* returned value must be negative on failure */
> +          return err < 0 ? err : -err;
> +        }
> +      }
> +
>         if (name) {
>           size_t length = strlen (busses[busno].name) + strlen (name) + 2;
>           str = malloc (length);
> @@ -751,9 +761,10 @@ rtems_libi2c_register_drv (const char *name, rtems_libi2c_drv_t * drvtbl,
>   
>           /* note that 'umask' is applied to 'mode' */
>           if (mknod (str, mode, dev)) {
> -          safe_printf( DRVNM
> -                   "Creating device node failed: %s; you can try to do it manually...\n",
> -                   strerror (errno));
> +          safe_printf ( DRVNM
> +                        "Creating device node failed: %s;\n"
> +                        "you can try to do it manually...\n",
> +                        strerror (errno));
>           }
>   
>           free (str);
> @@ -761,17 +772,11 @@ rtems_libi2c_register_drv (const char *name, rtems_libi2c_drv_t * drvtbl,
>   
>         drvs[i].drv = drvtbl;
>   
> -      if (drvtbl->ops->initialization_entry)
> -        err =
> -          drvs[i].drv->ops->initialization_entry (rtems_libi2c_major, minor,
> -                                                  0);
> -      else
> -        err = RTEMS_SUCCESSFUL;
> -
>         LIBUNLOCK ();
> -      return err ? -err : minor;
> +      return minor;
>       }
>     }
> +
>     LIBUNLOCK ();
>     return -RTEMS_TOO_MANY;
>   }

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
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