bus: mhi: Use bitfield operations for handling DWORDs of ring elements

Instead of using the hardcoded bits in DWORD definitions, let's use the
bitfield operations to make it more clear how the DWORDs are structured.
Suggested-by: NAlex Elder <elder@linaro.org>
Reviewed-by: NAlex Elder <elder@linaro.org>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220301160308.107452-7-manivannan.sadhasivam@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/host/internal.h

@@ -7,6 +7,7 @@
 #ifndef _MHI_INT_H
 #define _MHI_INT_H
 
+#include <linux/bitfield.h>
 #include <linux/mhi.h>
 
 extern struct bus_type mhi_bus_type;
@@ -205,58 +206,65 @@ enum mhi_cmd_type {
 /* No operation command */
 #define MHI_TRE_CMD_NOOP_PTR (0)
 #define MHI_TRE_CMD_NOOP_DWORD0 (0)
-#define MHI_TRE_CMD_NOOP_DWORD1 (cpu_to_le32(MHI_CMD_NOP << 16))
+#define MHI_TRE_CMD_NOOP_DWORD1 (cpu_to_le32(FIELD_PREP(GENMASK(23, 16), MHI_CMD_NOP)))
 
 /* Channel reset command */
 #define MHI_TRE_CMD_RESET_PTR (0)
 #define MHI_TRE_CMD_RESET_DWORD0 (0)
-#define MHI_TRE_CMD_RESET_DWORD1(chid) (cpu_to_le32((chid << 24) | \
-					(MHI_CMD_RESET_CHAN << 16)))
+#define MHI_TRE_CMD_RESET_DWORD1(chid) (cpu_to_le32(FIELD_PREP(GENMASK(31, 24), chid)) | \
+					FIELD_PREP(GENMASK(23, 16), MHI_CMD_RESET_CHAN))
 
 /* Channel stop command */
 #define MHI_TRE_CMD_STOP_PTR (0)
 #define MHI_TRE_CMD_STOP_DWORD0 (0)
-#define MHI_TRE_CMD_STOP_DWORD1(chid) (cpu_to_le32((chid << 24) | \
-				       (MHI_CMD_STOP_CHAN << 16)))
+#define MHI_TRE_CMD_STOP_DWORD1(chid) (cpu_to_le32(FIELD_PREP(GENMASK(31, 24), chid)) | \
+					FIELD_PREP(GENMASK(23, 16), MHI_CMD_STOP_CHAN))
 
 /* Channel start command */
 #define MHI_TRE_CMD_START_PTR (0)
 #define MHI_TRE_CMD_START_DWORD0 (0)
-#define MHI_TRE_CMD_START_DWORD1(chid) (cpu_to_le32((chid << 24) | \
-					(MHI_CMD_START_CHAN << 16)))
+#define MHI_TRE_CMD_START_DWORD1(chid) (cpu_to_le32(FIELD_PREP(GENMASK(31, 24), chid)) | \
+					FIELD_PREP(GENMASK(23, 16), MHI_CMD_START_CHAN))
 
 #define MHI_TRE_GET_DWORD(tre, word) (le32_to_cpu((tre)->dword[(word)]))
-#define MHI_TRE_GET_CMD_CHID(tre) ((MHI_TRE_GET_DWORD(tre, 1) >> 24) & 0xFF)
-#define MHI_TRE_GET_CMD_TYPE(tre) ((MHI_TRE_GET_DWORD(tre, 1) >> 16) & 0xFF)
+#define MHI_TRE_GET_CMD_CHID(tre) (FIELD_GET(GENMASK(31, 24), (MHI_TRE_GET_DWORD(tre, 1))))
+#define MHI_TRE_GET_CMD_TYPE(tre) (FIELD_GET(GENMASK(23, 16), (MHI_TRE_GET_DWORD(tre, 1))))
 
 /* Event descriptor macros */
 #define MHI_TRE_EV_PTR(ptr) (cpu_to_le64(ptr))
-#define MHI_TRE_EV_DWORD0(code, len) (cpu_to_le32((code << 24) | len))
-#define MHI_TRE_EV_DWORD1(chid, type) (cpu_to_le32((chid << 24) | (type << 16)))
+#define MHI_TRE_EV_DWORD0(code, len) (cpu_to_le32(FIELD_PREP(GENMASK(31, 24), code) | \
+						FIELD_PREP(GENMASK(15, 0), len)))
+#define MHI_TRE_EV_DWORD1(chid, type) (cpu_to_le32(FIELD_PREP(GENMASK(31, 24), chid) | \
+						FIELD_PREP(GENMASK(23, 16), type)))
 #define MHI_TRE_GET_EV_PTR(tre) (le64_to_cpu((tre)->ptr))
-#define MHI_TRE_GET_EV_CODE(tre) ((MHI_TRE_GET_DWORD(tre, 0) >> 24) & 0xFF)
-#define MHI_TRE_GET_EV_LEN(tre) (MHI_TRE_GET_DWORD(tre, 0) & 0xFFFF)
-#define MHI_TRE_GET_EV_CHID(tre) ((MHI_TRE_GET_DWORD(tre, 1) >> 24) & 0xFF)
-#define MHI_TRE_GET_EV_TYPE(tre) ((MHI_TRE_GET_DWORD(tre, 1) >> 16) & 0xFF)
-#define MHI_TRE_GET_EV_STATE(tre) ((MHI_TRE_GET_DWORD(tre, 0) >> 24) & 0xFF)
-#define MHI_TRE_GET_EV_EXECENV(tre) ((MHI_TRE_GET_DWORD(tre, 0) >> 24) & 0xFF)
+#define MHI_TRE_GET_EV_CODE(tre) (FIELD_GET(GENMASK(31, 24), (MHI_TRE_GET_DWORD(tre, 0))))
+#define MHI_TRE_GET_EV_LEN(tre) (FIELD_GET(GENMASK(15, 0), (MHI_TRE_GET_DWORD(tre, 0))))
+#define MHI_TRE_GET_EV_CHID(tre) (FIELD_GET(GENMASK(31, 24), (MHI_TRE_GET_DWORD(tre, 1))))
+#define MHI_TRE_GET_EV_TYPE(tre) (FIELD_GET(GENMASK(23, 16), (MHI_TRE_GET_DWORD(tre, 1))))
+#define MHI_TRE_GET_EV_STATE(tre) (FIELD_GET(GENMASK(31, 24), (MHI_TRE_GET_DWORD(tre, 0))))
+#define MHI_TRE_GET_EV_EXECENV(tre) (FIELD_GET(GENMASK(31, 24), (MHI_TRE_GET_DWORD(tre, 0))))
 #define MHI_TRE_GET_EV_SEQ(tre) MHI_TRE_GET_DWORD(tre, 0)
 #define MHI_TRE_GET_EV_TIME(tre) (MHI_TRE_GET_EV_PTR(tre))
 #define MHI_TRE_GET_EV_COOKIE(tre) lower_32_bits(MHI_TRE_GET_EV_PTR(tre))
-#define MHI_TRE_GET_EV_VEID(tre) ((MHI_TRE_GET_DWORD(tre, 0) >> 16) & 0xFF)
-#define MHI_TRE_GET_EV_LINKSPEED(tre) ((MHI_TRE_GET_DWORD(tre, 1) >> 24) & 0xFF)
-#define MHI_TRE_GET_EV_LINKWIDTH(tre) (MHI_TRE_GET_DWORD(tre, 0) & 0xFF)
+#define MHI_TRE_GET_EV_VEID(tre) (FIELD_GET(GENMASK(23, 16), (MHI_TRE_GET_DWORD(tre, 0))))
+#define MHI_TRE_GET_EV_LINKSPEED(tre) (FIELD_GET(GENMASK(31, 24), (MHI_TRE_GET_DWORD(tre, 1))))
+#define MHI_TRE_GET_EV_LINKWIDTH(tre) (FIELD_GET(GENMASK(7, 0), (MHI_TRE_GET_DWORD(tre, 0))))
 
 /* Transfer descriptor macros */
 #define MHI_TRE_DATA_PTR(ptr) (cpu_to_le64(ptr))
-#define MHI_TRE_DATA_DWORD0(len) (cpu_to_le32(len & MHI_MAX_MTU))
-#define MHI_TRE_DATA_DWORD1(bei, ieot, ieob, chain) (cpu_to_le32((2 << 16) | (bei << 10) \
-	| (ieot << 9) | (ieob << 8) | chain))
+#define MHI_TRE_DATA_DWORD0(len) (cpu_to_le32(FIELD_PREP(GENMASK(15, 0), len)))
+#define MHI_TRE_TYPE_TRANSFER 2
+#define MHI_TRE_DATA_DWORD1(bei, ieot, ieob, chain) (cpu_to_le32(FIELD_PREP(GENMASK(23, 16), \
+							MHI_TRE_TYPE_TRANSFER) | \
+							FIELD_PREP(BIT(10), bei) | \
+							FIELD_PREP(BIT(9), ieot) | \
+							FIELD_PREP(BIT(8), ieob) | \
+							FIELD_PREP(BIT(0), chain)))
 
 /* RSC transfer descriptor macros */
-#define MHI_RSCTRE_DATA_PTR(ptr, len) (cpu_to_le64(((u64)len << 48) | ptr))
+#define MHI_RSCTRE_DATA_PTR(ptr, len) (cpu_to_le64(FIELD_PREP(GENMASK(64, 48), len) | ptr))
 #define MHI_RSCTRE_DATA_DWORD0(cookie) (cpu_to_le32(cookie))
-#define MHI_RSCTRE_DATA_DWORD1 (cpu_to_le32(MHI_PKT_TYPE_COALESCING << 16))
+#define MHI_RSCTRE_DATA_DWORD1 (cpu_to_le32(FIELD_PREP(GENMASK(23, 16), MHI_PKT_TYPE_COALESCING)
 
 enum mhi_pkt_type {
 	MHI_PKT_TYPE_INVALID = 0x0,