2015-04-29 15:59:37

by Lee Jones

Subject: [PATCH 1/1] mailbox: Add ability for clients to request channels by name

This patch supplies a new framework API; mbox_request_channel_byname().

It works by supplying the usual client pointer as the first argument and
a string as the second. The API will search the client's node for a
'mbox-names' property then request a channel in the normal way using the
requested string's index as the expected second 'index' argument.

Signed-off-by: Lee Jones <[email protected]>
---
drivers/mailbox/mailbox.c | 23 +++++++++++++++++++++++
include/linux/mailbox_client.h | 2 ++
2 files changed, 25 insertions(+)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 19b491d..981a76cb 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -357,6 +357,29 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
}
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;
+ struct property *prop;
+ const char *mbox_name;
+ int index = 0;
+
+ if (!np) {
+ dev_err(cl->dev, "%s() only supports DT\n", __func__);
+ return ERR_PTR(-ENOSYS);
+ }
+
+ of_property_for_each_string(np, "mbox-names", prop, mbox_name) {
+ if (!strncmp(name, mbox_name, strlen(name)))
+ break;
+ index++;
+ }
+
+ return mbox_request_channel(cl, index);
+}
+EXPORT_SYMBOL_GPL(mbox_request_channel_byname);
+
/**
* mbox_free_channel - The client relinquishes control of a mailbox
* channel by this call.
diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h
index 1726ccb..4434871 100644
--- a/include/linux/mailbox_client.h
+++ b/include/linux/mailbox_client.h
@@ -40,6 +40,8 @@ struct mbox_client {
void (*tx_done)(struct mbox_client *cl, void *mssg, int r);
};

+struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
+ const char *name);
struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index);
int mbox_send_message(struct mbox_chan *chan, void *mssg);
void mbox_client_txdone(struct mbox_chan *chan, int r); /* atomic */
--
1.9.1

2015-05-11 14:41:00

by Jassi Brar

Subject: Re: [PATCH 1/1] mailbox: Add ability for clients to request channels by name

On 29 April 2015 at 21:29, Lee Jones <[email protected]> wrote:
> This patch supplies a new framework API; mbox_request_channel_byname().
>
> It works by supplying the usual client pointer as the first argument and
> a string as the second. The API will search the client's node for a
> 'mbox-names' property then request a channel in the normal way using the
> requested string's index as the expected second 'index' argument.
>
The api seems prudent. Thanks.

> Signed-off-by: Lee Jones <[email protected]>
> ---
> drivers/mailbox/mailbox.c | 23 +++++++++++++++++++++++
> include/linux/mailbox_client.h | 2 ++
> 2 files changed, 25 insertions(+)
>
> diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
> index 19b491d..981a76cb 100644
> --- a/drivers/mailbox/mailbox.c
> +++ b/drivers/mailbox/mailbox.c
> @@ -357,6 +357,29 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
> }
> 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;
> + struct property *prop;
> + const char *mbox_name;
> + int index = 0;
> +
> + if (!np) {
> + dev_err(cl->dev, "%s() only supports DT\n", __func__);
> + return ERR_PTR(-ENOSYS);
> + }
> +
> + of_property_for_each_string(np, "mbox-names", prop, mbox_name) {
> + if (!strncmp(name, mbox_name, strlen(name)))
> + break;
> + index++;
> + }
> +
> + return mbox_request_channel(cl, index);
>
'mbox-names' property is specified as optional in Mailbox bindings. We
don't want to return chan@0 if the property isn't populated.

Also please remove the line "The use of this property is discouraged
..." from Documentation/devicetree/bindings/mailbox/mailbox.txt now
that we add an api for just that.

Thanks.