[PATCH v10 11/12] soc: mediatek: cmdq: add cmdq_dev_get_client_reg function

[Bibby Hsieh <bibby.hsieh@mediatek.com>]

GCE cannot know the register base address, this function
can help cmdq client to get the cmdq_client_reg structure.

Signed-off-by: Bibby Hsieh <bibby.hsieh@mediatek.com>
---
 drivers/soc/mediatek/mtk-cmdq-helper.c | 28 ++++++++++++++++++++++++++
 include/linux/soc/mediatek/mtk-cmdq.h  | 21 +++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
index 70ad4d806fac..ad52ac3ccfbb 100644
--- a/drivers/soc/mediatek/mtk-cmdq-helper.c
+++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
@@ -27,6 +27,34 @@ struct cmdq_instruction {
 	u8 op;
 };
 
+int cmdq_dev_get_client_reg(struct device *dev,
+			    struct cmdq_client_reg *client_reg, int idx)
+{
+	struct of_phandle_args spec;
+	int err;
+
+	if (!client_reg)
+		return -ENOENT;
+
+	err = of_parse_phandle_with_args(dev->of_node, "mediatek,gce-client-reg",
+					 "#subsys-cells", idx, &spec);
+	if (err < 0) {
+		dev_err(dev,
+			"error %d can't parse gce-client-reg property (%d)",
+			err, idx);
+
+		return err;
+	}
+
+	client_reg->subsys = spec.args[0];
+	client_reg->offset = spec.args[1];
+	client_reg->size = spec.args[2];
+	of_node_put(spec.np);
+
+	return 0;
+}
+EXPORT_SYMBOL(cmdq_dev_get_client_reg);
+
 static void cmdq_client_timeout(struct timer_list *t)
 {
 	struct cmdq_client *client = from_timer(client, t, timer);
diff --git a/include/linux/soc/mediatek/mtk-cmdq.h b/include/linux/soc/mediatek/mtk-cmdq.h
index a345870a6d10..be402c4c740e 100644
--- a/include/linux/soc/mediatek/mtk-cmdq.h
+++ b/include/linux/soc/mediatek/mtk-cmdq.h
@@ -15,6 +15,12 @@
 
 struct cmdq_pkt;
 
+struct cmdq_client_reg {
+	u8 subsys;
+	u16 offset;
+	u16 size;
+};
+
 struct cmdq_client {
 	spinlock_t lock;
 	u32 pkt_cnt;
@@ -142,4 +148,19 @@ int cmdq_pkt_flush_async(struct cmdq_pkt *pkt, cmdq_async_flush_cb cb,
  */
 int cmdq_pkt_flush(struct cmdq_pkt *pkt);
 
+/**
+ * cmdq_dev_get_client_reg() - parse cmdq client reg from the device
+ *			       node of CMDQ client
+ * @dev:	device of CMDQ mailbox clienti
+ * @client_reg: CMDQ client reg pointer
+ * @idx:	the index of desired reg
+ *
+ * Return: 0 for success; else the error code is returned
+ *
+ * Help CMDQ client pasing the cmdq client reg
+ * from the device node of CMDQ client.
+ */
+int cmdq_dev_get_client_reg(struct device *dev,
+			    struct cmdq_client_reg *client_reg, int idx);
+
 #endif	/* __MTK_CMDQ_H__ */
-- 
2.18.0