On Fri, Jul 4, 2025 at 12:35 PM Anup Patel <apatel@ventanamicro.com> wrote:
>
> Introduce optional fw_node() callback which allows a mailbox controller
> driver to provide controller specific mapping using fwnode.
>
> The Linux OF framework already implements fwnode operations for the
> Linux DD framework so the fw_xlate() callback works fine with device
> tree as well.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
I missed adding Andy's Reviewed-by here which I will do in the
next revision.
Regards,
Anup
> ---
> drivers/mailbox/mailbox.c | 65 ++++++++++++++++++------------
> include/linux/mailbox_controller.h | 3 ++
> 2 files changed, 43 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
> index 5cd8ae222073..2acc6ec229a4 100644
> --- a/drivers/mailbox/mailbox.c
> +++ b/drivers/mailbox/mailbox.c
> @@ -15,6 +15,7 @@
> #include <linux/module.h>
> #include <linux/mutex.h>
> #include <linux/of.h>
> +#include <linux/property.h>
> #include <linux/spinlock.h>
>
> #include "mailbox.h"
> @@ -383,34 +384,56 @@ EXPORT_SYMBOL_GPL(mbox_bind_client);
> */
> struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
> {
> - struct device *dev = cl->dev;
> + struct fwnode_reference_args fwspec;
> + struct fwnode_handle *fwnode;
> struct mbox_controller *mbox;
> struct of_phandle_args spec;
> struct mbox_chan *chan;
> + struct device *dev;
> + unsigned int i;
> int ret;
>
> - if (!dev || !dev->of_node) {
> - pr_debug("%s: No owner device node\n", __func__);
> + dev = cl->dev;
> + if (!dev) {
> + pr_debug("No owner device\n");
> return ERR_PTR(-ENODEV);
> }
>
> - ret = of_parse_phandle_with_args(dev->of_node, "mboxes", "#mbox-cells",
> - index, &spec);
> + fwnode = dev_fwnode(dev);
> + if (!fwnode) {
> + dev_dbg(dev, "No owner fwnode\n");
> + return ERR_PTR(-ENODEV);
> + }
> +
> + ret = fwnode_property_get_reference_args(fwnode, "mboxes", "#mbox-cells",
> + 0, index, &fwspec);
> if (ret) {
> - dev_err(dev, "%s: can't parse \"mboxes\" property\n", __func__);
> + dev_err(dev, "%s: can't parse \"%s\" property\n", __func__, "mboxes");
> return ERR_PTR(ret);
> }
>
> + spec.np = to_of_node(fwspec.fwnode);
> + spec.args_count = fwspec.nargs;
> + for (i = 0; i < spec.args_count; i++)
> + spec.args[i] = fwspec.args[i];
> +
> scoped_guard(mutex, &con_mutex) {
> chan = ERR_PTR(-EPROBE_DEFER);
> - list_for_each_entry(mbox, &mbox_cons, node)
> - if (mbox->dev->of_node == spec.np) {
> - chan = mbox->of_xlate(mbox, &spec);
> - if (!IS_ERR(chan))
> - break;
> + list_for_each_entry(mbox, &mbox_cons, node) {
> + if (device_match_fwnode(mbox->dev, fwspec.fwnode)) {
> + if (mbox->fw_xlate) {
> + chan = mbox->fw_xlate(mbox, &fwspec);
> + if (!IS_ERR(chan))
> + break;
> + } else if (mbox->of_xlate) {
> + chan = mbox->of_xlate(mbox, &spec);
> + if (!IS_ERR(chan))
> + break;
> + }
> }
> + }
>
> - of_node_put(spec.np);
> + fwnode_handle_put(fwspec.fwnode);
>
> if (IS_ERR(chan))
> return chan;
> @@ -427,15 +450,8 @@ EXPORT_SYMBOL_GPL(mbox_request_channel);
> struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
> const char *name)
> {
> - struct device_node *np = cl->dev->of_node;
> - int index;
> -
> - if (!np) {
> - dev_err(cl->dev, "%s() currently only supports DT\n", __func__);
> - return ERR_PTR(-EINVAL);
> - }
> + int index = device_property_match_string(cl->dev, "mbox-names", name);
>
> - index = of_property_match_string(np, "mbox-names", name);
> if (index < 0) {
> dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",
> __func__, name);
> @@ -470,9 +486,8 @@ void mbox_free_channel(struct mbox_chan *chan)
> }
> EXPORT_SYMBOL_GPL(mbox_free_channel);
>
> -static struct mbox_chan *
> -of_mbox_index_xlate(struct mbox_controller *mbox,
> - const struct of_phandle_args *sp)
> +static struct mbox_chan *fw_mbox_index_xlate(struct mbox_controller *mbox,
> + const struct fwnode_reference_args *sp)
> {
> int ind = sp->args[0];
>
> @@ -523,8 +538,8 @@ int mbox_controller_register(struct mbox_controller *mbox)
> spin_lock_init(&chan->lock);
> }
>
> - if (!mbox->of_xlate)
> - mbox->of_xlate = of_mbox_index_xlate;
> + if (!mbox->fw_xlate && !mbox->of_xlate)
> + mbox->fw_xlate = fw_mbox_index_xlate;
>
> scoped_guard(mutex, &con_mutex)
> list_add_tail(&mbox->node, &mbox_cons);
> diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
> index ad01c4082358..80a427c7ca29 100644
> --- a/include/linux/mailbox_controller.h
> +++ b/include/linux/mailbox_controller.h
> @@ -66,6 +66,7 @@ struct mbox_chan_ops {
> * no interrupt rises. Ignored if 'txdone_irq' is set.
> * @txpoll_period: If 'txdone_poll' is in effect, the API polls for
> * last TX's status after these many millisecs
> + * @fw_xlate: Controller driver specific mapping of channel via fwnode
> * @of_xlate: Controller driver specific mapping of channel via DT
> * @poll_hrt: API private. hrtimer used to poll for TXDONE on all
> * channels.
> @@ -79,6 +80,8 @@ struct mbox_controller {
> bool txdone_irq;
> bool txdone_poll;
> unsigned txpoll_period;
> + struct mbox_chan *(*fw_xlate)(struct mbox_controller *mbox,
> + const struct fwnode_reference_args *sp);
> struct mbox_chan *(*of_xlate)(struct mbox_controller *mbox,
> const struct of_phandle_args *sp);
> /* Internal to API */
> --
> 2.43.0
>