Hi Hans,
On Thu, Apr 08, 2021 at 10:31:27PM +0200, Hans de Goede wrote:
> This can be used by Type-C controller drivers which use a standard
> usb-connector fwnode, with altmodes sub-node, to describe the available
> altmodes.
>
> Note there are is no devicetree bindings documentation for the altmodes
> node, this is deliberate. ATM the fwnodes used to register the altmodes
> are only used internally to pass platform info from a drivers/platform/x86
> driver to the type-c subsystem.
>
> When a devicetree user of this functionally comes up and the dt-bindings
> have been hashed out the internal use can be adjusted to match the
> dt-bindings.
>
> Currently the typec_port_register_altmodes_from_fwnode() function expects
> an "altmodes" child fwnode on port->dev with this "altmodes" fwnode having
> child fwnodes itself with each child containing 2 integer properties:
>
> 1. A "svid" property, which sets the id of the altmode, e.g. displayport
> altmode has a svid of 0xff01.
>
> 2. A "vdo" property, typically used as a bitmask describing the
> capabilities of the altmode, the bits in the vdo are specified in the
> specification of the altmode.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v2:
> - Drop the unnecessary fwnode parameter from
> typec_port_register_altmodes_from_fwnode()
> - Document the expected "altmodes" fwnode in the commit message for now
> as v2 of the patch-set drops the dt-bindings since there are not DT
> users for this yet
> ---
> drivers/usb/typec/class.c | 55 +++++++++++++++++++++++++++++++++++++++
> include/linux/usb/typec.h | 6 +++++
> 2 files changed, 61 insertions(+)
>
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index 45f0bf65e9ab..a82344fe1650 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -1978,6 +1978,61 @@ typec_port_register_altmode(struct typec_port *port,
> }
> EXPORT_SYMBOL_GPL(typec_port_register_altmode);
>
> +void typec_port_register_altmodes_from_fwnode(struct typec_port *port,
> + const struct typec_altmode_ops *ops, void *drvdata,
> + struct typec_altmode **altmodes, size_t n)
Couldn't we just call this typec_port_register_altmodes()?
> +{
> + struct fwnode_handle *altmodes_node, *child;
> + struct typec_altmode_desc desc;
> + struct typec_altmode *alt;
> + size_t index = 0;
> + u32 svid, vdo;
> + int ret;
> +
> + altmodes_node = device_get_named_child_node(&port->dev, "altmodes");
> + if (!altmodes_node)
> + return; /* No altmodes specified */
> +
> + child = NULL;
> + while ((child = fwnode_get_next_child_node(altmodes_node, child))) {
fwnode_for_each_child_node()?
> + ret = fwnode_property_read_u32(child, "svid", &svid);
> + if (ret) {
> + dev_err(&port->dev, "Error reading svid for altmode %s\n",
> + fwnode_get_name(child));
> + continue;
> + }
> +
> + ret = fwnode_property_read_u32(child, "vdo", &vdo);
> + if (ret) {
> + dev_err(&port->dev, "Error reading vdo for altmode %s\n",
> + fwnode_get_name(child));
> + continue;
> + }
> +
> + if (index >= n) {
> + dev_err(&port->dev, "Error not enough space for altmode %s\n",
> + fwnode_get_name(child));
> + continue;
> + }
> +
> + desc.svid = svid;
> + desc.vdo = vdo;
> + desc.mode = index + 1;
> + alt = typec_port_register_altmode(port, &desc);
> + if (IS_ERR(alt)) {
> + dev_err(&port->dev, "Error registering altmode %s\n",
> + fwnode_get_name(child));
> + continue;
> + }
> +
> + alt->ops = ops;
> + typec_altmode_set_drvdata(alt, drvdata);
> + altmodes[index] = alt;
> + index++;
> + }
> +}
> +EXPORT_SYMBOL_GPL(typec_port_register_altmodes_from_fwnode);
This is OK by me, but I've been wondering if it would be more clear to
just have a function fwnode_for_each_altmode() (I don't know if the
name is good enough).
int fwnode_for_each_altmode(struct fwnode_handle *fwnode,
int (*fn)(struct typec_altmode_desc *, void *),
void *data)
{
struct fwnode_handle *altmodes_node, *child;
struct typec_altmode_desc desc;
u32 svid, vdo;
int ret;
altmodes_node = fwnode_get_named_child_node(fwnode, "altmodes");
if (!altmodes_node)
return 0; /* No altmodes specified */
fwnode_for_each_child_node(altmodes_node, child) {
...
/* read the properties */
...
desc.svid = svid;
desc.vdo = vdo;
desc.mode = index + 1;
/* We need to add this member to struct typec_altmode_desc! */
desc.fwnode = client;
ret = fn(&desc, data);
if (ret)
return ret;
}
return 0;
}
Something like that. It would leave the registration of the alternate
modes to the drivers, which I think would actually be better.
If there ever is need, this can be also used for other things besides
mode registration.
What do you think?
Br,
--
heikki
