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NFC: Add a DEP link control netlink command
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NFC-DEP (Data Exchange Protocol) is an NFC MAC layer.
This command allows to enable and disable the DEP link on to which e.g.
LLCP can run.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Samuel Ortiz authored and John W. Linville committed Dec 14, 2011
1 parent db81a62 commit 1ed28f6
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Showing 5 changed files with 255 additions and 0 deletions.
14 changes: 14 additions & 0 deletions include/linux/nfc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,8 @@ enum nfc_commands {
NFC_CMD_GET_DEVICE,
NFC_CMD_DEV_UP,
NFC_CMD_DEV_DOWN,
NFC_CMD_DEP_LINK_UP,
NFC_CMD_DEP_LINK_DOWN,
NFC_CMD_START_POLL,
NFC_CMD_STOP_POLL,
NFC_CMD_GET_TARGET,
Expand All @@ -86,6 +88,8 @@ enum nfc_commands {
* @NFC_ATTR_TARGET_SENS_RES: NFC-A targets extra information such as NFCID
* @NFC_ATTR_TARGET_SEL_RES: NFC-A targets extra information (useful if the
* target is not NFC-Forum compliant)
* @NFC_ATTR_COMM_MODE: Passive or active mode
* @NFC_ATTR_RF_MODE: Initiator or target
*/
enum nfc_attrs {
NFC_ATTR_UNSPEC,
Expand All @@ -95,6 +99,8 @@ enum nfc_attrs {
NFC_ATTR_TARGET_INDEX,
NFC_ATTR_TARGET_SENS_RES,
NFC_ATTR_TARGET_SEL_RES,
NFC_ATTR_COMM_MODE,
NFC_ATTR_RF_MODE,
/* private: internal use only */
__NFC_ATTR_AFTER_LAST
};
Expand All @@ -111,6 +117,14 @@ enum nfc_attrs {

#define NFC_PROTO_MAX 6

/* NFC communication modes */
#define NFC_COMM_ACTIVE 0
#define NFC_COMM_PASSIVE 1

/* NFC RF modes */
#define NFC_RF_INITIATOR 0
#define NFC_RF_TARGET 1

/* NFC protocols masks used in bitsets */
#define NFC_PROTO_JEWEL_MASK (1 << NFC_PROTO_JEWEL)
#define NFC_PROTO_MIFARE_MASK (1 << NFC_PROTO_MIFARE)
Expand Down
11 changes: 11 additions & 0 deletions include/net/nfc/nfc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -52,6 +52,9 @@ struct nfc_ops {
int (*dev_down)(struct nfc_dev *dev);
int (*start_poll)(struct nfc_dev *dev, u32 protocols);
void (*stop_poll)(struct nfc_dev *dev);
int (*dep_link_up)(struct nfc_dev *dev, int target_idx,
u8 comm_mode, u8 rf_mode);
int (*dep_link_down)(struct nfc_dev *dev);
int (*activate_target)(struct nfc_dev *dev, u32 target_idx,
u32 protocol);
void (*deactivate_target)(struct nfc_dev *dev, u32 target_idx);
Expand All @@ -60,6 +63,9 @@ struct nfc_ops {
void *cb_context);
};

#define NFC_TARGET_IDX_ANY -1
#define NFC_MAX_GT_LEN 48

struct nfc_target {
u32 idx;
u32 supported_protocols;
Expand All @@ -83,6 +89,8 @@ struct nfc_dev {
bool dev_up;
bool polling;
bool remote_activated;
bool dep_link_up;
u32 dep_rf_mode;
struct nfc_genl_data genl_data;
u32 supported_protocols;

Expand Down Expand Up @@ -165,4 +173,7 @@ struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp);
int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
int ntargets);

int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode);

#endif /* __NET_NFC_H */
77 changes: 77 additions & 0 deletions net/nfc/core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -181,6 +181,83 @@ int nfc_stop_poll(struct nfc_dev *dev)
return rc;
}

int nfc_dep_link_up(struct nfc_dev *dev, int target_index,
u8 comm_mode, u8 rf_mode)
{
int rc = 0;

pr_debug("dev_name=%s comm:%d rf:%d\n",
dev_name(&dev->dev), comm_mode, rf_mode);

if (!dev->ops->dep_link_up)
return -EOPNOTSUPP;

device_lock(&dev->dev);

if (!device_is_registered(&dev->dev)) {
rc = -ENODEV;
goto error;
}

if (dev->dep_link_up == true) {
rc = -EALREADY;
goto error;
}

rc = dev->ops->dep_link_up(dev, target_index, comm_mode, rf_mode);

error:
device_unlock(&dev->dev);
return rc;
}

int nfc_dep_link_down(struct nfc_dev *dev)
{
int rc = 0;

pr_debug("dev_name=%s\n", dev_name(&dev->dev));

if (!dev->ops->dep_link_down)
return -EOPNOTSUPP;

device_lock(&dev->dev);

if (!device_is_registered(&dev->dev)) {
rc = -ENODEV;
goto error;
}

if (dev->dep_link_up == false) {
rc = -EALREADY;
goto error;
}

if (dev->dep_rf_mode == NFC_RF_TARGET) {
rc = -EOPNOTSUPP;
goto error;
}

rc = dev->ops->dep_link_down(dev);
if (!rc) {
dev->dep_link_up = false;
nfc_genl_dep_link_down_event(dev);
}

error:
device_unlock(&dev->dev);
return rc;
}

int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode)
{
dev->dep_link_up = true;
dev->dep_rf_mode = rf_mode;

return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
}
EXPORT_SYMBOL(nfc_dep_link_is_up);

/**
* nfc_activate_target - prepare the target for data exchange
*
Expand Down
144 changes: 144 additions & 0 deletions net/nfc/netlink.c
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,8 @@ static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
[NFC_ATTR_DEVICE_NAME] = { .type = NLA_STRING,
.len = NFC_DEVICE_NAME_MAXSIZE },
[NFC_ATTR_PROTOCOLS] = { .type = NLA_U32 },
[NFC_ATTR_COMM_MODE] = { .type = NLA_U8 },
[NFC_ATTR_RF_MODE] = { .type = NLA_U8 },
};

static int nfc_genl_send_target(struct sk_buff *msg, struct nfc_target *target,
Expand Down Expand Up @@ -311,6 +313,75 @@ static int nfc_genl_dump_devices_done(struct netlink_callback *cb)
return 0;
}

int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode)
{
struct sk_buff *msg;
void *hdr;

pr_debug("DEP link is up\n");

msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!msg)
return -ENOMEM;

hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_CMD_DEP_LINK_UP);
if (!hdr)
goto free_msg;

NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);
if (rf_mode == NFC_RF_INITIATOR)
NLA_PUT_U32(msg, NFC_ATTR_TARGET_INDEX, target_idx);
NLA_PUT_U8(msg, NFC_ATTR_COMM_MODE, comm_mode);
NLA_PUT_U8(msg, NFC_ATTR_RF_MODE, rf_mode);

genlmsg_end(msg, hdr);

dev->dep_link_up = true;

genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

return 0;

nla_put_failure:
genlmsg_cancel(msg, hdr);
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}

int nfc_genl_dep_link_down_event(struct nfc_dev *dev)
{
struct sk_buff *msg;
void *hdr;

pr_debug("DEP link is down\n");

msg = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!msg)
return -ENOMEM;

hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
NFC_CMD_DEP_LINK_DOWN);
if (!hdr)
goto free_msg;

NLA_PUT_U32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx);

genlmsg_end(msg, hdr);

genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_ATOMIC);

return 0;

nla_put_failure:
genlmsg_cancel(msg, hdr);
free_msg:
nlmsg_free(msg);
return -EMSGSIZE;
}

static int nfc_genl_get_device(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
Expand Down Expand Up @@ -398,6 +469,8 @@ static int nfc_genl_start_poll(struct sk_buff *skb, struct genl_info *info)
u32 idx;
u32 protocols;

pr_debug("Poll start\n");

if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_PROTOCOLS])
return -EINVAL;
Expand Down Expand Up @@ -452,6 +525,67 @@ static int nfc_genl_stop_poll(struct sk_buff *skb, struct genl_info *info)
return rc;
}

static int nfc_genl_dep_link_up(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc, tgt_idx;
u32 idx;
u8 comm, rf;

pr_debug("DEP link up\n");

if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
!info->attrs[NFC_ATTR_COMM_MODE] ||
!info->attrs[NFC_ATTR_RF_MODE])
return -EINVAL;

idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
if (!info->attrs[NFC_ATTR_TARGET_INDEX])
tgt_idx = NFC_TARGET_IDX_ANY;
else
tgt_idx = nla_get_u32(info->attrs[NFC_ATTR_TARGET_INDEX]);

comm = nla_get_u8(info->attrs[NFC_ATTR_COMM_MODE]);
rf = nla_get_u8(info->attrs[NFC_ATTR_RF_MODE]);

if (comm != NFC_COMM_ACTIVE && comm != NFC_COMM_PASSIVE)
return -EINVAL;

if (rf != NFC_RF_INITIATOR && comm != NFC_RF_TARGET)
return -EINVAL;

dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;

rc = nfc_dep_link_up(dev, tgt_idx, comm, rf);

nfc_put_device(dev);

return rc;
}

static int nfc_genl_dep_link_down(struct sk_buff *skb, struct genl_info *info)
{
struct nfc_dev *dev;
int rc;
u32 idx;

if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
return -EINVAL;

idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);

dev = nfc_get_device(idx);
if (!dev)
return -ENODEV;

rc = nfc_dep_link_down(dev);

nfc_put_device(dev);
return rc;
}

static struct genl_ops nfc_genl_ops[] = {
{
.cmd = NFC_CMD_GET_DEVICE,
Expand Down Expand Up @@ -480,6 +614,16 @@ static struct genl_ops nfc_genl_ops[] = {
.doit = nfc_genl_stop_poll,
.policy = nfc_genl_policy,
},
{
.cmd = NFC_CMD_DEP_LINK_UP,
.doit = nfc_genl_dep_link_up,
.policy = nfc_genl_policy,
},
{
.cmd = NFC_CMD_DEP_LINK_DOWN,
.doit = nfc_genl_dep_link_down,
.policy = nfc_genl_policy,
},
{
.cmd = NFC_CMD_GET_TARGET,
.dumpit = nfc_genl_dump_targets,
Expand Down
9 changes: 9 additions & 0 deletions net/nfc/nfc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -68,6 +68,10 @@ int nfc_genl_targets_found(struct nfc_dev *dev);
int nfc_genl_device_added(struct nfc_dev *dev);
int nfc_genl_device_removed(struct nfc_dev *dev);

int nfc_genl_dep_link_up_event(struct nfc_dev *dev, u32 target_idx,
u8 comm_mode, u8 rf_mode);
int nfc_genl_dep_link_down_event(struct nfc_dev *dev);

struct nfc_dev *nfc_get_device(unsigned idx);

static inline void nfc_put_device(struct nfc_dev *dev)
Expand Down Expand Up @@ -102,6 +106,11 @@ int nfc_start_poll(struct nfc_dev *dev, u32 protocols);

int nfc_stop_poll(struct nfc_dev *dev);

int nfc_dep_link_up(struct nfc_dev *dev, int target_idx,
u8 comm_mode, u8 rf_mode);

int nfc_dep_link_down(struct nfc_dev *dev);

int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol);

int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx);
Expand Down

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