[PATCH 2/3] soc: mediatek: cmdq-helper: add legacy GCE ISA support

[Roman Vivchar via B4 Relay]

From: Roman Vivchar <rva333 at protonmail.com>

Some SoCs, such as mt6572, have different WRITE and POLL instruction
encoding. Instead of 16-bit offset and 8-bit subsystem ID, old GCEs have
22-bit offset and 2-bit subsystem ID.

Extend cmdq_instruction struct with additional union and struct to hold
the legacy format of instruction encoding. Add legacy_isa to select
legacy GCE ISA when writing instruction. Finally, add special handing
for legacy_isa cases.

While mt6572 GCE supports 22-bit offsets, the parameter type for offset
remains 16 bit, because all mt6572 GCE mmsys consumers are in the 0xffff
range.

Signed-off-by: Roman Vivchar <rva333 at protonmail.com>
---
 drivers/soc/mediatek/mtk-cmdq-helper.c   | 55 ++++++++++++++++++++++----------
 include/linux/mailbox/mtk-cmdq-mailbox.h |  1 +
 2 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-cmdq-helper.c b/drivers/soc/mediatek/mtk-cmdq-helper.c
index f8ee6c9ade89..094732405080 100644
--- a/drivers/soc/mediatek/mtk-cmdq-helper.c
+++ b/drivers/soc/mediatek/mtk-cmdq-helper.c
@@ -31,18 +31,27 @@ struct cmdq_instruction {
 		};
 	};
 	union {
-		u16 offset;
-		u16 event;
-		u16 reg_dst;
-	};
-	union {
-		u8 subsys;
 		struct {
-			u8 sop:5;
-			u8 arg_c_t:1;
-			u8 src_t:1;
-			u8 dst_t:1;
-		};
+			union {
+				u16 offset;
+				u16 event;
+				u16 reg_dst;
+			};
+			union {
+				u8 subsys;
+				struct {
+					u8 sop:5;
+					u8 arg_c_t:1;
+					u8 src_t:1;
+					u8 dst_t:1;
+				};
+			};
+		} __packed;
+
+		struct {
+			u32 offset_legacy:22;
+			u32 subsys_legacy:2;
+		} __packed;
 	};
 	u8 op;
 };
@@ -219,10 +228,16 @@ int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value)
 {
 	struct cmdq_instruction inst = {
 		.op = CMDQ_CODE_WRITE,
-		.value = value,
-		.offset = offset,
-		.subsys = subsys
+		.value = value
 	};
+
+	if (pkt->priv.legacy_isa) {
+		inst.offset_legacy = offset;
+		inst.subsys_legacy = subsys;
+	} else {
+		inst.offset = offset;
+		inst.subsys = subsys;
+	}
 	return cmdq_pkt_append_command(pkt, inst);
 }
 EXPORT_SYMBOL(cmdq_pkt_write);
@@ -459,10 +474,16 @@ int cmdq_pkt_poll(struct cmdq_pkt *pkt, u8 subsys,
 {
 	struct cmdq_instruction inst = {
 		.op = CMDQ_CODE_POLL,
-		.value = value,
-		.offset = offset,
-		.subsys = subsys
+		.value = value
 	};
+
+	if (pkt->priv.legacy_isa) {
+		inst.offset_legacy = offset;
+		inst.subsys_legacy = subsys;
+	} else {
+		inst.offset = offset;
+		inst.subsys = subsys;
+	}
 	return cmdq_pkt_append_command(pkt, inst);
 }
 EXPORT_SYMBOL(cmdq_pkt_poll);
diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
index 07c1bfbdb8c4..9fcebc4ca864 100644
--- a/include/linux/mailbox/mtk-cmdq-mailbox.h
+++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
@@ -72,6 +72,7 @@ struct cmdq_cb_data {
 
 struct cmdq_mbox_priv {
 	u8 shift_pa;
+	bool legacy_isa;
 	dma_addr_t mminfra_offset;
 };
 

-- 
2.54.0