[char-misc-next V3] mei: send OS type to the FW

[Tomas Winkler]

From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>

Tell the FW that we are running a sane OS and TPM2_ChangeEPS()
is supported. This workaround was added to support other broken OS
and we need to follow here. The command is sent just once at the boot time.

Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
---
V2: 1. Use endain annotation
    2. Drop bitfields
    3. Drop trace dev_dbg out from the hook function
    4. Add error code to failure info message
V3:  mkhi header structure should be __packed

 drivers/misc/mei/bus-fixup.c | 95 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 9e10d86e3887..a9226d809b17 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -38,6 +38,9 @@ static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;
 #define MEI_UUID_WD UUID_LE(0x05B79A6F, 0x4628, 0x4D7F, \
 			    0x89, 0x9D, 0xA9, 0x15, 0x14, 0xCB, 0x32, 0xAB)
 
+#define MEI_UUID_MKHIF_FIX UUID_LE(0x55213584, 0x9a29, 0x4916, \
+			0xba, 0xdf, 0xf, 0xb7, 0xed, 0x68, 0x2a, 0xeb)
+
 #define MEI_UUID_ANY NULL_UUID_LE
 
 /**
@@ -69,6 +72,97 @@ static void blacklist(struct mei_cl_device *cldev)
 	cldev->do_match = 0;
 }
 
+#define OSTYPE_LINUX    2
+struct mei_os_ver {
+	__le16 build;
+	__le16 reserved1;
+	u8  os_type;
+	u8  major;
+	u8  minor;
+	u8  reserved2;
+} __packed;
+
+#define MKHI_FEATURE_PTT 0x10
+
+struct mkhi_rule_id {
+	__le16 rule_type;
+	u8 feature_id;
+	u8 reserved;
+} __packed;
+
+struct mkhi_fwcaps {
+	struct mkhi_rule_id id;
+	u8 len;
+	u8 data[0];
+} __packed;
+
+#define MKHI_FWCAPS_GROUP_ID 0x3
+#define MKHI_FWCAPS_SET_OS_VER_APP_RULE_CMD 6
+struct mkhi_msg_hdr {
+	u8  group_id;
+	u8  command;
+	u8  reserved;
+	u8  result;
+} __packed;
+
+struct mkhi_msg {
+	struct mkhi_msg_hdr hdr;
+	u8 data[0];
+} __packed;
+
+static int mei_osver(struct mei_cl_device *cldev)
+{
+	int ret;
+	const size_t size = sizeof(struct mkhi_msg_hdr) +
+			    sizeof(struct mkhi_fwcaps) +
+			    sizeof(struct mei_os_ver);
+	size_t length = 8;
+	char buf[size];
+	struct mkhi_msg *req;
+	struct mkhi_fwcaps *fwcaps;
+	struct mei_os_ver *os_ver;
+	unsigned int mode = MEI_CL_IO_TX_BLOCKING | MEI_CL_IO_TX_INTERNAL;
+
+	memset(buf, 0, size);
+
+	req = (struct mkhi_msg *)buf;
+	req->hdr.group_id = MKHI_FWCAPS_GROUP_ID;
+	req->hdr.command = MKHI_FWCAPS_SET_OS_VER_APP_RULE_CMD;
+
+	fwcaps = (struct mkhi_fwcaps *)req->data;
+
+	fwcaps->id.rule_type = 0x0;
+	fwcaps->id.feature_id = MKHI_FEATURE_PTT;
+	fwcaps->len = sizeof(*os_ver);
+	os_ver = (struct mei_os_ver *)fwcaps->data;
+	os_ver->os_type = OSTYPE_LINUX;
+
+	ret = __mei_cl_send(cldev->cl, buf, size, mode);
+	if (ret < 0)
+		return ret;
+
+	ret = __mei_cl_recv(cldev->cl, buf, length);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static void mei_mkhi_fix(struct mei_cl_device *cldev)
+{
+	int ret;
+
+	ret = mei_cldev_enable(cldev);
+	if (ret)
+		return;
+
+	ret = mei_osver(cldev);
+	if (ret)
+		dev_info(&cldev->dev, "OS version command failed %d\n", ret);
+
+	mei_cldev_disable(cldev);
+}
+
 /**
  * mei_wd - wd client on the bus, change protocol version
  *   as the API has changed.
@@ -310,6 +404,7 @@ static struct mei_fixup {
 	MEI_FIXUP(MEI_UUID_NFC_INFO, blacklist),
 	MEI_FIXUP(MEI_UUID_NFC_HCI, mei_nfc),
 	MEI_FIXUP(MEI_UUID_WD, mei_wd),
+	MEI_FIXUP(MEI_UUID_MKHIF_FIX, mei_mkhi_fix),
 };
 
 /**
-- 
2.7.4