mailbox: qcom-ipcc: Dynamic alloc for channel arrangement

Dynamic alloc for channel arrangement instead of static alloced
array, it is more flexible and can reduce memory usage.

Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

Author: Huang Yiwei

drivers/mailbox/qcom-ipcc.c

@@ -13,8 +13,6 @@
 
 #include <dt-bindings/mailbox/qcom-ipcc.h>
 
-#define IPCC_MBOX_MAX_CHAN		48
-
 /* IPCC Register offsets */
 #define IPCC_REG_SEND_ID		0x0c
 #define IPCC_REG_RECV_ID		0x10
@@ -52,9 +50,10 @@ struct qcom_ipcc {
 	struct device *dev;
 	void __iomem *base;
 	struct irq_domain *irq_domain;
-	struct mbox_chan chan[IPCC_MBOX_MAX_CHAN];
-	struct qcom_ipcc_chan_info mchan[IPCC_MBOX_MAX_CHAN];
+	struct mbox_chan *chans;
+	struct qcom_ipcc_chan_info *mchan;
 	struct mbox_controller mbox;
+	int num_chans;
 	int irq;
 };
 
@@ -166,41 +165,87 @@ static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
 	struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
 	struct qcom_ipcc_chan_info *mchan;
 	struct mbox_chan *chan;
-	unsigned int i;
+	struct device *dev;
+	int chan_id;
+
+	dev = ipcc->dev;
 
 	if (ph->args_count != 2)
 		return ERR_PTR(-EINVAL);
 
-	for (i = 0; i < IPCC_MBOX_MAX_CHAN; i++) {
-		chan = &ipcc->chan[i];
-		if (!chan->con_priv) {
-			mchan = &ipcc->mchan[i];
-			mchan->client_id = ph->args[0];
-			mchan->signal_id = ph->args[1];
-			chan->con_priv = mchan;
-			break;
-		}
+	for (chan_id = 0; chan_id < mbox->num_chans; chan_id++) {
+		chan = &ipcc->chans[chan_id];
+		mchan = chan->con_priv;
 
-		chan = NULL;
+		if (!mchan)
+			break;
+		else if (mchan->client_id == ph->args[0] &&
+				mchan->signal_id == ph->args[1])
+			return ERR_PTR(-EBUSY);
 	}
 
-	return chan ?: ERR_PTR(-EBUSY);
+	if (chan_id >= mbox->num_chans)
+		return ERR_PTR(-EBUSY);
+
+	mchan = devm_kzalloc(dev, sizeof(*mchan), GFP_KERNEL);
+	if (!mchan)
+		return ERR_PTR(-ENOMEM);
+
+	mchan->client_id = ph->args[0];
+	mchan->signal_id = ph->args[1];
+	chan->con_priv = mchan;
+
+	return chan;
 }
 
 static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
 	.send_data = qcom_ipcc_mbox_send_data,
 	.shutdown = qcom_ipcc_mbox_shutdown,
 };
 
-static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc)
+static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc,
+				struct device_node *controller_dn)
 {
+	struct of_phandle_args curr_ph;
+	struct device_node *client_dn;
 	struct mbox_controller *mbox;
 	struct device *dev = ipcc->dev;
+	int i, j, ret;
+
+	/*
+	 * Find out the number of clients interested in this mailbox
+	 * and create channels accordingly.
+	 */
+	ipcc->num_chans = 0;
+	for_each_node_with_property(client_dn, "mboxes") {
+		if (!of_device_is_available(client_dn))
+			continue;
+		i = of_count_phandle_with_args(client_dn,
+						"mboxes", "#mbox-cells");
+		for (j = 0; j < i; j++) {
+			ret = of_parse_phandle_with_args(client_dn, "mboxes",
+						"#mbox-cells", j, &curr_ph);
+			of_node_put(curr_ph.np);
+			if (!ret && curr_ph.np == controller_dn) {
+				ipcc->num_chans++;
+				break;
+			}
+		}
+	}
+
+	/* If no clients are found, skip registering as a mbox controller */
+	if (!ipcc->num_chans)
+		return 0;
+
+	ipcc->chans = devm_kcalloc(dev, ipcc->num_chans,
+					sizeof(struct mbox_chan), GFP_KERNEL);
+	if (!ipcc->chans)
+		return -ENOMEM;
 
 	mbox = &ipcc->mbox;
 	mbox->dev = dev;
-	mbox->num_chans = IPCC_MBOX_MAX_CHAN;
-	mbox->chans = ipcc->chan;
+	mbox->num_chans = ipcc->num_chans;
+	mbox->chans = ipcc->chans;
 	mbox->ops = &ipcc_mbox_chan_ops;
 	mbox->of_xlate = qcom_ipcc_mbox_xlate;
 	mbox->txdone_irq = false;
@@ -233,22 +278,25 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
 	if (!ipcc->irq_domain)
 		return -ENOMEM;
 
-	ret = qcom_ipcc_setup_mbox(ipcc);
+	ret = qcom_ipcc_setup_mbox(ipcc, pdev->dev.of_node);
 	if (ret)
 		goto err_mbox;
 
 	ret = devm_request_irq(&pdev->dev, ipcc->irq, qcom_ipcc_irq_fn,
 			       IRQF_TRIGGER_HIGH, "ipcc", ipcc);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
-		goto err_mbox;
+		goto err_req_irq;
 	}
 
 	enable_irq_wake(ipcc->irq);
 	platform_set_drvdata(pdev, ipcc);
 
 	return 0;
 
+err_req_irq:
+	if (ipcc->num_chans)
+		mbox_controller_unregister(&ipcc->mbox);
 err_mbox:
 	irq_domain_remove(ipcc->irq_domain);