soc: mediatek: cmdq: Add inline functions for !CONFIG_MTK_CMDQ

In preparation for a cleanup of ifdef instances of IS_REACHABLE() for
the CONFIG_MTK_CMDQ configuration option, add inline functions that
will either return a failure or, for void functions, do nothing.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20230222094253.23678-9-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Author: AngeloGioacchino Del Regno

include/linux/soc/mediatek/mtk-cmdq.h

@@ -27,6 +27,8 @@ struct cmdq_client {
 	struct mbox_chan *chan;
 };
 
+#if IS_ENABLED(CONFIG_MTK_CMDQ)
+
 /**
  * cmdq_dev_get_client_reg() - parse cmdq client reg from the device
  *			       node of CMDQ client
@@ -277,4 +279,116 @@ int cmdq_pkt_finalize(struct cmdq_pkt *pkt);
  */
 int cmdq_pkt_flush_async(struct cmdq_pkt *pkt);
 
+#else /* IS_ENABLED(CONFIG_MTK_CMDQ) */
+
+static inline int cmdq_dev_get_client_reg(struct device *dev,
+					  struct cmdq_client_reg *client_reg, int idx)
+{
+	return -ENODEV;
+}
+
+static inline struct cmdq_client *cmdq_mbox_create(struct device *dev, int index)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void cmdq_mbox_destroy(struct cmdq_client *client) { }
+
+static inline  struct cmdq_pkt *cmdq_pkt_create(struct cmdq_client *client, size_t size)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void cmdq_pkt_destroy(struct cmdq_pkt *pkt) { }
+
+static inline int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys,
+				      u16 offset, u32 value, u32 mask)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_read_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
+				  u16 addr_low, u16 reg_idx)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_write_s(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
+				   u16 addr_low, u16 src_reg_idx)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_write_s_mask(struct cmdq_pkt *pkt, u16 high_addr_reg_idx,
+					u16 addr_low, u16 src_reg_idx, u32 mask)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_write_s_value(struct cmdq_pkt *pkt, u8 high_addr_reg_idx,
+					 u16 addr_low, u32 value)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_write_s_mask_value(struct cmdq_pkt *pkt, u8 high_addr_reg_idx,
+					      u16 addr_low, u32 value, u32 mask)
+{
+	return -ENOENT;
+}
+
+static inline int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event, bool clear)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_set_event(struct cmdq_pkt *pkt, u16 event)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_poll(struct cmdq_pkt *pkt, u8 subsys,
+				u16 offset, u32 value)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_poll_mask(struct cmdq_pkt *pkt, u8 subsys,
+				     u16 offset, u32 value, u32 mask)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_assign(struct cmdq_pkt *pkt, u16 reg_idx, u32 value)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_jump(struct cmdq_pkt *pkt, dma_addr_t addr)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
+{
+	return -EINVAL;
+}
+
+static inline int cmdq_pkt_flush_async(struct cmdq_pkt *pkt)
+{
+	return -EINVAL;
+}
+
+#endif /* IS_ENABLED(CONFIG_MTK_CMDQ) */
+
 #endif	/* __MTK_CMDQ_H__ */