mailbox: mtk-cmdq: Move and partially refactor clocks probe

Move the clocks probe to a new cmdq_get_clocks() function; while
at it, partially refactor the code:

Drop the clk_names[] array and assign clock names to the array
of clk_bulk_data with devm_kasprintf() instead, slightly reduce
the indentation for the multi-gce clock probe path and add a
comment describing the reason why we get clocks of other GCE
instance instead of just the clock from the one that it is
getting probed.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

drivers/mailbox/mtk-cmdq-mailbox.c

@@ -578,16 +578,59 @@ static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
 	return &mbox->chans[ind];
 }
 
+static int cmdq_get_clocks(struct device *dev, struct cmdq *cmdq)
+{
+	static const char * const gce_name = "gce";
+	struct device_node *node, *parent = dev->of_node->parent;
+	struct clk_bulk_data *clks;
+
+	if (cmdq->pdata->gce_num == 1) {
+		clks = &cmdq->clocks[0];
+
+		clks->id = gce_name;
+		clks->clk = devm_clk_get(dev, NULL);
+		if (IS_ERR(clks->clk))
+			return dev_err_probe(dev, PTR_ERR(clks->clk),
+					     "failed to get gce clock\n");
+
+		return 0;
+	}
+
+	/*
+	 * If there is more than one GCE, get the clocks for the others too,
+	 * as the clock of the main GCE must be enabled for additional IPs
+	 * to be reachable.
+	 */
+	for_each_child_of_node(parent, node) {
+		int alias_id = of_alias_get_id(node, gce_name);
+
+		if (alias_id < 0 || alias_id >= cmdq->pdata->gce_num)
+			continue;
+
+		clks = &cmdq->clocks[alias_id];
+
+		clks->id = devm_kasprintf(dev, GFP_KERNEL, "gce%d", alias_id);
+		if (!clks->id) {
+			of_node_put(node);
+			return -ENOMEM;
+		}
+
+		clks->clk = of_clk_get(node, 0);
+		if (IS_ERR(clks->clk)) {
+			of_node_put(node);
+			return dev_err_probe(dev, PTR_ERR(clks->clk),
+					     "failed to get gce%d clock\n", alias_id);
+		}
+	}
+
+	return 0;
+}
+
 static int cmdq_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cmdq *cmdq;
 	int err, i;
-	struct device_node *phandle = dev->of_node;
-	struct device_node *node;
-	int alias_id = 0;
-	static const char * const clk_name = "gce";
-	static const char * const clk_names[] = { "gce0", "gce1" };
 
 	cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
 	if (!cmdq)
@@ -612,29 +655,9 @@ static int cmdq_probe(struct platform_device *pdev)
 	dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
 		dev, cmdq->base, cmdq->irq);
 
-	if (cmdq->pdata->gce_num > 1) {
-		for_each_child_of_node(phandle->parent, node) {
-			alias_id = of_alias_get_id(node, clk_name);
-			if (alias_id >= 0 && alias_id < cmdq->pdata->gce_num) {
-				cmdq->clocks[alias_id].id = clk_names[alias_id];
-				cmdq->clocks[alias_id].clk = of_clk_get(node, 0);
-				if (IS_ERR(cmdq->clocks[alias_id].clk)) {
-					of_node_put(node);
-					return dev_err_probe(dev,
-							     PTR_ERR(cmdq->clocks[alias_id].clk),
-							     "failed to get gce clk: %d\n",
-							     alias_id);
-				}
-			}
-		}
-	} else {
-		cmdq->clocks[alias_id].id = clk_name;
-		cmdq->clocks[alias_id].clk = devm_clk_get(&pdev->dev, NULL);
-		if (IS_ERR(cmdq->clocks[alias_id].clk)) {
-			return dev_err_probe(dev, PTR_ERR(cmdq->clocks[alias_id].clk),
-					     "failed to get gce clk\n");
-		}
-	}
+	err = cmdq_get_clocks(dev, cmdq);
+	if (err)
+		return err;
 
 	cmdq->mbox.dev = dev;
 	cmdq->mbox.chans = devm_kcalloc(dev, cmdq->pdata->thread_nr,