On Mon, 2 Jun 2014 14:41:01 +0100, Lee Jones <lee.jones@xxxxxxxxxx> wrote:
> We have a problem. There are lots of I2C device ID tables scattered
> around the kernel which are redundant in all Device Tree and/or ACPI
> only supported device drivers. After recent discussions it has become
> apparent that the only thing blocking the complete removal of these
> tables is the continued support of 'register an I2C device via sysfs'
> functionality. As the sysfs method doesn't know anything about Device
> Tree or ACPI, we can not pass any nodes in. This patch searches all
> known Device Tree nodes and attempts to acquire a match from the
> device name provided via sysfs. It can not fail, but if found assigns
> the matching of_node to i2c_board_info prior to registering.
Ummm... blech! :-)
It shouldn't actually be necessary to have a node when instantiating an
i2c_device... in fact, there /shouldn't/ be a node if the device is
getting instantiated by had via sysfs. If there was a node, then I would
expect a device to have been created at the same time.
I think panto's overlays solve the problem where a node actually is
required to instantiate the device by actually adding a node and letting
the i2c subsystem create the associated device automatically.
g.
>
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> drivers/i2c/i2c-core.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 7c7f4b8..2e47641 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -64,6 +64,7 @@ static DEFINE_IDR(i2c_adapter_idr);
>
> static struct device_type i2c_client_type;
> static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
> +static struct device_node *of_i2c_type_to_node(char *type);
>
> static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
>
> @@ -863,6 +864,8 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
> return -EINVAL;
> }
>
> + info.of_node = of_i2c_type_to_node(info.type);
> +
> client = i2c_new_device(adap, &info);
> if (!client)
> return -EINVAL;
> @@ -1088,8 +1091,36 @@ struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
> return i2c_verify_adapter(dev);
> }
> EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
> +
> +static struct device_node *of_i2c_type_to_node(char *type)
> +{
> + struct device_node *np;
> + const char *compatible, *name;
> + int len;
> +
> + if (!type)
> + return NULL;
> +
> + for_each_of_allnodes(np) {
> + compatible = of_get_property(np, "compatible", &len);
> + if (!compatible)
> + continue;
> +
> + name = strchr(compatible, ',');
> + if (!name)
> + name = compatible;
> + else
> + name++;
> +
> + if (!strncmp(name, type, len - (name - compatible)))
> + return np;
> + }
> +
> + return NULL;
> +}
> #else
> static void of_i2c_register_devices(struct i2c_adapter *adap) { }
> +static struct device_node *of_i2c_type_to_node(char *type) { return NULL; }
> #endif /* CONFIG_OF */
>
> /* ACPI support code */
> --
> 1.8.3.2
>
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
