On Tue, Aug 25, 2009 at 11:36:21AM +0200, Christian Herzig wrote:
> Add to the pca954x driver the ability to check the
> actual channel. The channel property is readable only.
>
> Signed-off-by: Christian Herzig <christian.herzig@xxxxxxxxxxx>
> ---
> drivers/i2c/muxes/pca954x.c | 18 ++++++++++++++++++
> 1 files changed, 18 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
> index 59d3917..ba4fef1 100644
> --- a/drivers/i2c/muxes/pca954x.c
> +++ b/drivers/i2c/muxes/pca954x.c
> @@ -56,6 +56,8 @@ enum pca_type {
> pca_9548,
> };
>
> +static u8 channel;
> +
Nack. Why are you using global variable? Please use reentrant code.
> struct pca954x {
> struct i2c_client *client;
> struct i2c_client dev;
> @@ -208,6 +210,17 @@ static int pca954x_deselect_mux(struct i2c_adapter *adap,
> return pca954x_xfer(adap, client, I2C_SMBUS_WRITE, ®val);
> }
>
> +/* called when reading channel property */
> +static ssize_t read_channel(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + snprintf(buf, 8, "%d\n", channel);
> + return strlen(buf)+1;
I suppose you can simply do:
return sprintf(buf "%d\n", channel);
> +}
> +
> +/* define read and write method for channel attribute and its access rights */
> +static DEVICE_ATTR(channel, S_IRUGO, read_channel, NULL);
> +
> /*
> * I2C init/probing/exit functions
> */
> @@ -271,6 +284,11 @@ static int pca954x_probe(struct i2c_client *client,
> i, chips[data->type].muxtype == pca954x_ismux ?
> "mux" : "switch", client->name);
>
> + /* create channel attribute file in sysfs */
> + ret = sysfs_create_file(&client->dev.kobj, &dev_attr_channel);
> + if (0 != ret)
> + printk(KERN_ERR "creating file in sysfs failed\n");
> +
No remove code?
> return 0;
>
> virt_reg_failed:
> --
> 1.6.0.1
>
Ciao,
Rodolfo
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