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authorElliot Berman <quic_eberman@quicinc.com>2023-04-10 19:16:52 +0300
committerJassi Brar <jaswinder.singh@linaro.org>2023-04-18 19:48:55 +0300
commit85a953806557dbf25d16e8c132b5b9b100d16496 (patch)
tree75e37c08b175f66f2ba0a3ea54a1560368659097 /drivers/mailbox
parent6a8f57ae2eb07ab39a6f0ccad60c760743051026 (diff)
downloadlinux-85a953806557dbf25d16e8c132b5b9b100d16496.tar.xz
mailbox: Allow direct registration to a channel
Support virtual mailbox controllers and clients which are not platform devices or come from the devicetree by allowing them to match client to channel via some other mechanism. Tested-by: Sudeep Holla <sudeep.holla@arm.com> (pcc) Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Diffstat (limited to 'drivers/mailbox')
-rw-r--r--drivers/mailbox/mailbox.c96
1 files changed, 68 insertions, 28 deletions
diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 4229b9b5da98..adf36c05fa43 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -317,6 +317,71 @@ int mbox_flush(struct mbox_chan *chan, unsigned long timeout)
}
EXPORT_SYMBOL_GPL(mbox_flush);
+static int __mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl)
+{
+ struct device *dev = cl->dev;
+ unsigned long flags;
+ int ret;
+
+ if (chan->cl || !try_module_get(chan->mbox->dev->driver->owner)) {
+ dev_dbg(dev, "%s: mailbox not free\n", __func__);
+ return -EBUSY;
+ }
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->msg_free = 0;
+ chan->msg_count = 0;
+ chan->active_req = NULL;
+ chan->cl = cl;
+ init_completion(&chan->tx_complete);
+
+ if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
+ chan->txdone_method = TXDONE_BY_ACK;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ if (chan->mbox->ops->startup) {
+ ret = chan->mbox->ops->startup(chan);
+
+ if (ret) {
+ dev_err(dev, "Unable to startup the chan (%d)\n", ret);
+ mbox_free_channel(chan);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * mbox_bind_client - Request a mailbox channel.
+ * @chan: The mailbox channel to bind the client to.
+ * @cl: Identity of the client requesting the channel.
+ *
+ * The Client specifies its requirements and capabilities while asking for
+ * a mailbox channel. It can't be called from atomic context.
+ * The channel is exclusively allocated and can't be used by another
+ * client before the owner calls mbox_free_channel.
+ * After assignment, any packet received on this channel will be
+ * handed over to the client via the 'rx_callback'.
+ * The framework holds reference to the client, so the mbox_client
+ * structure shouldn't be modified until the mbox_free_channel returns.
+ *
+ * Return: 0 if the channel was assigned to the client successfully.
+ * <0 for request failure.
+ */
+int mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl)
+{
+ int ret;
+
+ mutex_lock(&con_mutex);
+ ret = __mbox_bind_client(chan, cl);
+ mutex_unlock(&con_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mbox_bind_client);
+
/**
* mbox_request_channel - Request a mailbox channel.
* @cl: Identity of the client requesting the channel.
@@ -340,7 +405,6 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
struct mbox_controller *mbox;
struct of_phandle_args spec;
struct mbox_chan *chan;
- unsigned long flags;
int ret;
if (!dev || !dev->of_node) {
@@ -372,33 +436,9 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
return chan;
}
- if (chan->cl || !try_module_get(mbox->dev->driver->owner)) {
- dev_dbg(dev, "%s: mailbox not free\n", __func__);
- mutex_unlock(&con_mutex);
- return ERR_PTR(-EBUSY);
- }
-
- spin_lock_irqsave(&chan->lock, flags);
- chan->msg_free = 0;
- chan->msg_count = 0;
- chan->active_req = NULL;
- chan->cl = cl;
- init_completion(&chan->tx_complete);
-
- if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
- chan->txdone_method = TXDONE_BY_ACK;
-
- spin_unlock_irqrestore(&chan->lock, flags);
-
- if (chan->mbox->ops->startup) {
- ret = chan->mbox->ops->startup(chan);
-
- if (ret) {
- dev_err(dev, "Unable to startup the chan (%d)\n", ret);
- mbox_free_channel(chan);
- chan = ERR_PTR(ret);
- }
- }
+ ret = __mbox_bind_client(chan, cl);
+ if (ret)
+ chan = ERR_PTR(ret);
mutex_unlock(&con_mutex);
return chan;