[PATCH v14 09/10] soc: mediatek: cmdq: add cmdq_dev_get_client_reg function

[Bibby Hsieh]

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.hs...@mediatek.com>
Reviewed-by: CK Hu <ck...@mediatek.com>
Reviewed-by: Houlong Wei <houlong....@mediatek.com>
---
 drivers/soc/mediatek/mtk-cmdq-helper.c | 29 ++++++++++++++++++++++++++
 include/linux/soc/mediatek/mtk-cmdq.h  | 21 +++++++++++++++++++
 2 files changed, 50 insertions(+)

diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c 
b/drivers/soc/mediatek/mtk-cmdq-helper.c
index bec7bb6c3988..3037fbf206ef 100644
--- a/drivers/soc/mediatek/mtk-cmdq-helper.c
+++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
@@ -27,6 +27,35 @@ 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_fixed_args(dev->of_node,
+                                              "mediatek,gce-client-reg",
+                                              3, 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 = (u8)spec.args[0];
+       client_reg->offset = (u16)spec.args[1];
+       client_reg->size = (u16)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 92bd5b5c6341..a74c1d5acdf3 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;
@@ -24,6 +30,21 @@ struct cmdq_client {
        u32 timeout_ms; /* in unit of microsecond */
 };
 
+/**
+ * cmdq_dev_get_client_reg() - parse cmdq client reg from the device
+ *                            node of CMDQ client
+ * @dev:       device of CMDQ mailbox client
+ * @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 parsing 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);
+
 /**
  * cmdq_mbox_create() - create CMDQ mailbox client and channel
  * @dev:       device of CMDQ mailbox client
-- 
2.18.0