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mei: bus: link client devices instead of host clients
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MEI bus was designed around nfc and was hard to extend.
Instead of the hard coded way of adding the devices on the mei bus
we scan the whole me client list and create a device for each
eligible me client (mei_cl_bus_rescan); currently we support
only clients with single connection and fixed address clients.
NFC radio name detection is run as a fixup routine

The patch replaces handling the device list based on struct me_cl
to device list based on me_cl_devices. The creating a connection
is pushed from the device creation time to device enablement.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Tomas Winkler authored and Greg Kroah-Hartman committed Aug 4, 2015
1 parent b39910c commit 6009595
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Showing 5 changed files with 213 additions and 310 deletions.
288 changes: 62 additions & 226 deletions drivers/misc/mei/bus-fixup.c
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,11 @@
#define MEI_UUID_NFC_INFO UUID_LE(0xd2de1625, 0x382d, 0x417d, \
0x48, 0xa4, 0xef, 0xab, 0xba, 0x8a, 0x12, 0x06)

static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;

#define MEI_UUID_NFC_HCI UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50, \
0x94, 0xd4, 0x50, 0x26, 0x67, 0x23, 0x77, 0x5c)

#define MEI_UUID_ANY NULL_UUID_LE

/**
Expand Down Expand Up @@ -93,68 +98,10 @@ struct mei_nfc_if_version {
u8 radio_type;
} __packed;

struct mei_nfc_connect {
u8 fw_ivn;
u8 vendor_id;
} __packed;

struct mei_nfc_connect_resp {
u8 fw_ivn;
u8 vendor_id;
u16 me_major;
u16 me_minor;
u16 me_hotfix;
u16 me_build;
} __packed;

struct mei_nfc_hci_hdr {
u8 cmd;
u8 status;
u16 req_id;
u32 reserved;
u16 data_size;
} __packed;

#define MEI_NFC_CMD_MAINTENANCE 0x00
#define MEI_NFC_CMD_HCI_SEND 0x01
#define MEI_NFC_CMD_HCI_RECV 0x02

#define MEI_NFC_SUBCMD_CONNECT 0x00
#define MEI_NFC_SUBCMD_IF_VERSION 0x01

#define MEI_NFC_HEADER_SIZE 10

/**
* struct mei_nfc_dev - NFC mei device
*
* @me_cl: NFC me client
* @cl: NFC host client
* @cl_info: NFC info host client
* @init_work: perform connection to the info client
* @fw_ivn: NFC Interface Version Number
* @vendor_id: NFC manufacturer ID
* @radio_type: NFC radio type
* @bus_name: bus name
*
*/
struct mei_nfc_dev {
struct mei_me_client *me_cl;
struct mei_cl *cl;
struct mei_cl *cl_info;
struct work_struct init_work;
u8 fw_ivn;
u8 vendor_id;
u8 radio_type;
const char *bus_name;
};

/* UUIDs for NFC F/W clients */
const uuid_le mei_nfc_guid = UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50,
0x94, 0xd4, 0x50, 0x26,
0x67, 0x23, 0x77, 0x5c);

static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;

/* Vendors */
#define MEI_NFC_VENDOR_INSIDE 0x00
#define MEI_NFC_VENDOR_NXP 0x01
Expand All @@ -163,27 +110,6 @@ static const uuid_le mei_nfc_info_guid = MEI_UUID_NFC_INFO;
#define MEI_NFC_VENDOR_INSIDE_UREAD 0x00
#define MEI_NFC_VENDOR_NXP_PN544 0x01

static void mei_nfc_free(struct mei_nfc_dev *ndev)
{
if (!ndev)
return;

if (ndev->cl) {
list_del(&ndev->cl->device_link);
mei_cl_unlink(ndev->cl);
kfree(ndev->cl);
}

if (ndev->cl_info) {
list_del(&ndev->cl_info->device_link);
mei_cl_unlink(ndev->cl_info);
kfree(ndev->cl_info);
}

mei_me_cl_put(ndev->me_cl);
kfree(ndev);
}

/**
* mei_nfc_if_version - get NFC interface version
*
Expand Down Expand Up @@ -264,177 +190,86 @@ static const char *mei_nfc_radio_name(struct mei_nfc_if_version *ver)
return NULL;
}

static void mei_nfc_init(struct work_struct *work)
/**
* mei_nfc - The nfc fixup function. The function retrieves nfc radio
* name and set is as device attribute so we can load
* the proper device driver for it
*
* @cldev: me client device (nfc)
*/
static void mei_nfc(struct mei_cl_device *cldev)
{
struct mei_device *bus;
struct mei_cl_device *cldev;
struct mei_nfc_dev *ndev;
struct mei_cl *cl_info;
struct mei_me_client *me_cl_info;
struct mei_nfc_if_version version;
struct mei_cl *cl;
struct mei_me_client *me_cl = NULL;
struct mei_nfc_if_version ver;
const char *radio_name = NULL;
int ret;

ndev = container_of(work, struct mei_nfc_dev, init_work);
bus = cldev->bus;

cl_info = ndev->cl_info;
bus = cl_info->dev;
dev_dbg(bus->dev, "running hook %s: %pUl match=%d\n",
__func__, mei_me_cl_uuid(cldev->me_cl), cldev->do_match);

mutex_lock(&bus->device_lock);

/* check for valid client id */
me_cl_info = mei_me_cl_by_uuid(bus, &mei_nfc_info_guid);
if (!me_cl_info) {
mutex_unlock(&bus->device_lock);
dev_info(bus->dev, "nfc: failed to find the info client\n");
goto err;
}

if (mei_cl_connect(cl_info, me_cl_info, NULL) < 0) {
mei_me_cl_put(me_cl_info);
mutex_unlock(&bus->device_lock);
dev_err(bus->dev, "Could not connect to the NFC INFO ME client");

goto err;
/* we need to connect to INFO GUID */
cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
if (IS_ERR(cl)) {
ret = PTR_ERR(cl);
cl = NULL;
dev_err(bus->dev, "nfc hook alloc failed %d\n", ret);
goto out;
}
mei_me_cl_put(me_cl_info);
mutex_unlock(&bus->device_lock);

if (mei_nfc_if_version(cl_info, &version) < 0) {
dev_err(bus->dev, "Could not get the NFC interface version");

goto err;
me_cl = mei_me_cl_by_uuid(bus, &mei_nfc_info_guid);
if (!me_cl) {
ret = -ENOTTY;
dev_err(bus->dev, "Cannot find nfc info %d\n", ret);
goto out;
}

ndev->fw_ivn = version.fw_ivn;
ndev->vendor_id = version.vendor_id;
ndev->radio_type = version.radio_type;

dev_info(bus->dev, "NFC MEI VERSION: IVN 0x%x Vendor ID 0x%x Type 0x%x\n",
ndev->fw_ivn, ndev->vendor_id, ndev->radio_type);

mutex_lock(&bus->device_lock);

if (mei_cl_disconnect(cl_info) < 0) {
mutex_unlock(&bus->device_lock);
dev_err(bus->dev, "Could not disconnect the NFC INFO ME client");

goto err;
ret = mei_cl_connect(cl, me_cl, NULL);
if (ret < 0) {
dev_err(&cldev->dev, "Can't connect to the NFC INFO ME ret = %d\n",
ret);
goto out;
}

mutex_unlock(&bus->device_lock);

ndev->bus_name = mei_nfc_radio_name(&version);
ret = mei_nfc_if_version(cl, &ver);
if (ret)
goto disconnect;

if (!ndev->bus_name) {
dev_err(bus->dev, "Could not build the bus ID name\n");
return;
}
radio_name = mei_nfc_radio_name(&ver);

cldev = mei_cl_add_device(bus, ndev->me_cl, ndev->cl,
ndev->bus_name);
if (!cldev) {
dev_err(bus->dev, "Could not add the NFC device to the MEI bus\n");

goto err;
if (!radio_name) {
ret = -ENOENT;
dev_err(&cldev->dev, "Can't get the NFC interface version ret = %d\n",
ret);
goto disconnect;
}

cldev->priv_data = ndev;


return;
dev_dbg(bus->dev, "nfc radio %s\n", radio_name);
strlcpy(cldev->name, radio_name, sizeof(cldev->name));

err:
disconnect:
mutex_lock(&bus->device_lock);
mei_nfc_free(ndev);
mutex_unlock(&bus->device_lock);
if (mei_cl_disconnect(cl) < 0)
dev_err(bus->dev, "Can't disconnect the NFC INFO ME\n");

}
mei_cl_flush_queues(cl, NULL);

out:
mei_cl_unlink(cl);
mutex_unlock(&bus->device_lock);
mei_me_cl_put(me_cl);
kfree(cl);

int mei_nfc_host_init(struct mei_device *bus, struct mei_me_client *me_cl)
{
struct mei_nfc_dev *ndev;
struct mei_cl *cl_info, *cl;
int ret;


/* in case of internal reset bail out
* as the device is already setup
*/
cl = mei_cl_bus_find_cl_by_uuid(bus, mei_nfc_guid);
if (cl)
return 0;

ndev = kzalloc(sizeof(struct mei_nfc_dev), GFP_KERNEL);
if (!ndev) {
ret = -ENOMEM;
goto err;
}

ndev->me_cl = mei_me_cl_get(me_cl);
if (!ndev->me_cl) {
ret = -ENODEV;
goto err;
}

cl_info = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
if (IS_ERR(cl_info)) {
ret = PTR_ERR(cl_info);
goto err;
}

list_add_tail(&cl_info->device_link, &bus->device_list);

ndev->cl_info = cl_info;

cl = mei_cl_alloc_linked(bus, MEI_HOST_CLIENT_ID_ANY);
if (IS_ERR(cl)) {
ret = PTR_ERR(cl);
goto err;
}

list_add_tail(&cl->device_link, &bus->device_list);

ndev->cl = cl;

INIT_WORK(&ndev->init_work, mei_nfc_init);
schedule_work(&ndev->init_work);

return 0;

err:
mei_nfc_free(ndev);

return ret;
}

void mei_nfc_host_exit(struct mei_device *bus)
{
struct mei_nfc_dev *ndev;
struct mei_cl *cl;
struct mei_cl_device *cldev;

cl = mei_cl_bus_find_cl_by_uuid(bus, mei_nfc_guid);
if (!cl)
return;

cldev = cl->cldev;
if (!cldev)
return;

ndev = (struct mei_nfc_dev *)cldev->priv_data;
if (ndev)
cancel_work_sync(&ndev->init_work);

cldev->priv_data = NULL;

/* Need to remove the device here
* since mei_nfc_free will unlink the clients
*/
mei_cl_remove_device(cldev);
if (ret)
cldev->do_match = 0;

mutex_lock(&bus->device_lock);
mei_nfc_free(ndev);
mutex_unlock(&bus->device_lock);
dev_dbg(bus->dev, "end of fixup match = %d\n", cldev->do_match);
}

#define MEI_FIXUP(_uuid, _hook) { _uuid, _hook }
Expand All @@ -446,6 +281,7 @@ static struct mei_fixup {
} mei_fixups[] = {
MEI_FIXUP(MEI_UUID_ANY, number_of_connections),
MEI_FIXUP(MEI_UUID_NFC_INFO, blacklist),
MEI_FIXUP(MEI_UUID_NFC_HCI, mei_nfc),
};

/**
Expand Down
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