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path: root/drivers/firmware/arm_scmi/mailbox.c
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Diffstat (limited to 'drivers/firmware/arm_scmi/mailbox.c')
-rw-r--r--drivers/firmware/arm_scmi/mailbox.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
index 0d9c9538b7f4..112c285deb97 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -52,6 +52,39 @@ static bool mailbox_chan_available(struct device_node *of_node, int idx)
"#mbox-cells", idx, NULL);
}
+static int mailbox_chan_validate(struct device *cdev)
+{
+ int num_mb, num_sh, ret = 0;
+ struct device_node *np = cdev->of_node;
+
+ num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+ num_sh = of_count_phandle_with_args(np, "shmem", NULL);
+ /* Bail out if mboxes and shmem descriptors are inconsistent */
+ if (num_mb <= 0 || num_sh > 2 || num_mb != num_sh) {
+ dev_warn(cdev, "Invalid channel descriptor for '%s'\n",
+ of_node_full_name(np));
+ return -EINVAL;
+ }
+
+ if (num_sh > 1) {
+ struct device_node *np_tx, *np_rx;
+
+ np_tx = of_parse_phandle(np, "shmem", 0);
+ np_rx = of_parse_phandle(np, "shmem", 1);
+ /* SCMI Tx and Rx shared mem areas have to be distinct */
+ if (!np_tx || !np_rx || np_tx == np_rx) {
+ dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",
+ of_node_full_name(np));
+ ret = -EINVAL;
+ }
+
+ of_node_put(np_tx);
+ of_node_put(np_rx);
+ }
+
+ return ret;
+}
+
static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
bool tx)
{
@@ -64,6 +97,10 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
resource_size_t size;
struct resource res;
+ ret = mailbox_chan_validate(cdev);
+ if (ret)
+ return ret;
+
smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
if (!smbox)
return -ENOMEM;