Bluetooth: btintel: Add iBT register access over HCI support
Add regmap ibt to support Intel Bluetooth silicon register access
over HCI. Intel BT/FM combo chip allows to read/write some registers
(e.g. FM registers) via its HCI interface.
Read/Write operations are performed via a HCI transaction composed of
a HCI command (host->controller) followed by a HCI command complete
event (controller->host). Read/Write Command opcodes can be specified
to the regmap init function.
We define data formats which are intel/vendor specific.
Register Read/Write HCI command payload (Host):
Field: | REG ADDR | MODE | DATA_LEN | DATA... |
size: | 32b | 8b | 8b | 8b* |
Register Read HCI command complete event payload (Controller):
Field: | CMD STATUS | REG ADDR | DATA... |
size: | 8b | 32b | 8b* |
Register Write HCI command complete event payload (Controller):
Field: | CMD_STATUS |
size: | 8b |
Since this payload is HCI encapsulated, Little Endian byte order is
used.
Write/Read Example:
If we write 0x0000002a at address 0x00008c04, with opcode_write 0xfc5d,
The resulting transaction is (btmon trace):
< HCI Command (0x3f|0x005d) plen 10 [hci0]
04 8c 00 00 02 04 2a 00 00 00
> HCI Event (0x0e) plen 4
Unknown (0x3f|0x005d) ncmd 1
00
Then, if we read the same register with opcode_read 0xfc5e:
< HCI Command (0x3f|0x005e) plen 6 [hci0]
04 8c 00 00 02 04
> HCI Event (0x0e) plen 12 [hci0]
Unknown (0x3f|0x005e) ncmd 1
00 04 8c 00 00 2a 00 00 00
Signed-off-by: Loic Poulain <loic.poulain@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
index 52deaf2..f0655c4 100644
--- a/drivers/bluetooth/btintel.h
+++ b/drivers/bluetooth/btintel.h
@@ -80,6 +80,9 @@
const void *param);
int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name);
+struct regmap *btintel_regmap_init(struct hci_dev *hdev, u16 opcode_read,
+ u16 opcode_write);
+
#else
static inline int btintel_check_bdaddr(struct hci_dev *hdev)
@@ -113,4 +116,10 @@
return -EOPNOTSUPP;
}
+static inline struct regmap *btintel_regmap_init(struct hci_dev *hdev,
+ u16 opcode_read,
+ u16 opcode_write)
+{
+ return ERR_PTR(-EINVAL);
+}
#endif
