diff mbox

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

Message ID 1430323164-26945-1-git-send-email-lee.jones@linaro.org
State New
Headers show

Commit Message

Lee Jones April 29, 2015, 3:59 p.m. UTC
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 <lee.jones@linaro.org>
---
 drivers/mailbox/mailbox.c      | 23 +++++++++++++++++++++++
 include/linux/mailbox_client.h |  2 ++
 2 files changed, 25 insertions(+)

Comments

Jassi Brar May 11, 2015, 2:40 p.m. UTC | #1
On 29 April 2015 at 21:29, Lee Jones <lee.jones@linaro.org> 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 <lee.jones@linaro.org>
> ---
>  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.
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diff mbox

Patch

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 */