Hi Doug,
On Mon, Jan 14, 2013 at 10:53:21AM -0800, Doug Anderson wrote:
> This allows you to get the equivalent functionality of
> i2c_add_numbered_adapter() with all data in the device tree and no
> special case code in your driver. This is a common device tree
> technique.
>
> For quick reference, the FDT syntax for using an alias to provide an
> ID looks like:
> aliases {
> i2c0 = &i2c_0;
> i2c1 = &i2c_1;
> };
>
> Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> Acked-by: Haojian Zhuang <haojian.zhuang@xxxxxxxxx>
> ---
> Changes in v2: None
>
> drivers/i2c/i2c-core.c | 105 +++++++++++++++++++++++++++++++++++-------------
> 1 files changed, 77 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index e388590..a60ed6d 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -921,13 +921,81 @@ out_list:
> }
>
> /**
> + * i2c_get_number_from_dt - get the adapter number based on dt alias
> + * @adap: the adapter to look at
> + *
> + * Check whether there's an alias in the FDT that gives an ID for this i2c
> + * device. Use an alias like "i2c<nr>", like:
> + * aliases {
> + * i2c0 = &i2c_0;
> + * i2c1 = &i2c_1;
> + * };
> + *
> + * Returns the ID if found. If no alias is found returns -1.
> + */
> +static int i2c_get_number_from_dt(struct i2c_adapter *adap)
i2c_get_id_from_dt()?
> +{
> + struct device *dev = &adap->dev;
> + int id;
> +
> + if (!dev->of_node)
> + return -1;
-ESOMETHING?
> +
> + id = of_alias_get_id(dev->of_node, "i2c");
> + if (id < 0)
> + return -1;
> + return id;
Simply 'return of_alias_get_id(...)'? Even more, since this function
boils down to calling of_alias_get_id only and is only used once, I'd
think we can implement that directly and drop this function. That
shouldn't hurt readability.
> +}
> +
> +/**
> + * _i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
> + * @adap: the adapter to register (with adap->nr initialized)
> + * Context: can sleep
> + *
> + * See i2c_add_numbered_adapter() for details.
> + */
> +static int _i2c_add_numbered_adapter(struct i2c_adapter *adap)
All other internal functions are prefixed with '__'.
> +{
> + int id;
> + int status;
> +
> + /* Handled by wrappers */
> + BUG_ON(adap->nr == -1);
Is that a reason to halt the kernel? WARN and bailing out would do IMO.
> +
> + if (adap->nr & ~MAX_IDR_MASK)
> + return -EINVAL;
Note the idr-cleanup series from Tejun Heo. Given that his series is
scheduled for v3.9, I'd like to have your patches on top of his.
Thanks,
Wolfram
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