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net/can: Add can_dlc2len and can_len2dlc for CAN FD.
authorJan Charvat <charvj10@fel.cvut.cz>
Mon, 14 Sep 2020 08:13:38 +0000 (10:13 +0200)
committerPaolo Bonzini <pbonzini@redhat.com>
Wed, 30 Sep 2020 17:11:37 +0000 (19:11 +0200)
Signed-off-by: Jan Charvat <charvj10@fel.cvut.cz>
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Reviewed-by: Vikram Garhwal <fnu.vikram@xilinx.com>
Message-Id: <0a2efc6ef9c458505952ed230e49ae25cad7f324.1600069689.git.pisa@cmp.felk.cvut.cz>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
include/net/can_emu.h
net/can/can_core.c

index cab98ee..6f9b206 100644 (file)
@@ -122,4 +122,8 @@ int can_bus_client_set_filters(CanBusClientState *,
                                const struct qemu_can_filter *filters,
                                size_t filters_cnt);
 
+uint8_t can_dlc2len(uint8_t can_dlc);
+
+uint8_t can_len2dlc(uint8_t len);
+
 #endif
index 90f4d85..0115d78 100644 (file)
 #include "net/can_emu.h"
 #include "qom/object_interfaces.h"
 
+/* CAN DLC to real data length conversion helpers */
+
+static const uint8_t dlc2len[] = {
+    0, 1, 2, 3, 4, 5, 6, 7,
+    8, 12, 16, 20, 24, 32, 48, 64
+};
+
+/* get data length from can_dlc with sanitized can_dlc */
+uint8_t can_dlc2len(uint8_t can_dlc)
+{
+    return dlc2len[can_dlc & 0x0F];
+}
+
+static const uint8_t len2dlc[] = {
+    0, 1, 2, 3, 4, 5, 6, 7, 8,                              /* 0 - 8 */
+    9, 9, 9, 9,                                             /* 9 - 12 */
+    10, 10, 10, 10,                                         /* 13 - 16 */
+    11, 11, 11, 11,                                         /* 17 - 20 */
+    12, 12, 12, 12,                                         /* 21 - 24 */
+    13, 13, 13, 13, 13, 13, 13, 13,                         /* 25 - 32 */
+    14, 14, 14, 14, 14, 14, 14, 14,                         /* 33 - 40 */
+    14, 14, 14, 14, 14, 14, 14, 14,                         /* 41 - 48 */
+    15, 15, 15, 15, 15, 15, 15, 15,                         /* 49 - 56 */
+    15, 15, 15, 15, 15, 15, 15, 15                          /* 57 - 64 */
+};
+
+/* map the sanitized data length to an appropriate data length code */
+uint8_t can_len2dlc(uint8_t len)
+{
+    if (unlikely(len > 64)) {
+        return 0xF;
+    }
+
+    return len2dlc[len];
+}
+
 struct CanBusState {
     Object object;