[Bluetooth] Add automatic sniff mode support

This patch introduces the automatic sniff mode feature. This allows
the host to switch idle connections into sniff mode to safe power.

Signed-off-by: Ulisses Furquim <ulissesf@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

2 files changed, 86 insertions, 38 deletions

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 99c53f6b8252..b2bdb1aa0429 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -101,9 +101,10 @@ enum {
 #define HCIINQUIRY      _IOR('H', 240, int)
 
 /* HCI timeouts */
-#define HCI_CONN_TIMEOUT        (HZ * 40)
-#define HCI_DISCONN_TIMEOUT     (HZ * 2)
-#define HCI_CONN_IDLE_TIMEOUT   (HZ * 60)
+#define HCI_CONNECT_TIMEOUT     (40000) /* 40 seconds */
+#define HCI_DISCONN_TIMEOUT     (2000)  /* 2 seconds */
+#define HCI_IDLE_TIMEOUT        (6000)  /* 6 seconds */
+#define HCI_INIT_TIMEOUT        (10000) /* 10 seconds */
 
 /* HCI Packet types */
 #define HCI_COMMAND_PKT         0x01
@@ -145,7 +146,7 @@ enum {
 #define LMP_TACCURACY   0x10
 #define LMP_RSWITCH     0x20
 #define LMP_HOLD        0x40
-#define LMP_SNIF        0x80
+#define LMP_SNIFF       0x80
 
 #define LMP_PARK        0x01
 #define LMP_RSSI        0x02
@@ -160,13 +161,21 @@ enum {
 #define LMP_PSCHEME     0x02
 #define LMP_PCONTROL    0x04
 
+#define LMP_SNIFF_SUBR  0x02
+
+/* Connection modes */
+#define HCI_CM_ACTIVE   0x0000
+#define HCI_CM_HOLD     0x0001
+#define HCI_CM_SNIFF    0x0002
+#define HCI_CM_PARK     0x0003
+
 /* Link policies */
 #define HCI_LP_RSWITCH  0x0001
 #define HCI_LP_HOLD     0x0002
 #define HCI_LP_SNIFF    0x0004
 #define HCI_LP_PARK     0x0008
 
-/* Link mode */
+/* Link modes */
 #define HCI_LM_ACCEPT   0x8000
 #define HCI_LM_MASTER   0x0001
 #define HCI_LM_AUTH     0x0002
@@ -192,7 +201,7 @@ struct hci_rp_read_loc_version {
 } __attribute__ ((packed));
 
 #define OCF_READ_LOCAL_FEATURES 0x0003
-struct hci_rp_read_loc_features {
+struct hci_rp_read_local_features {
         __u8 status;
         __u8 features[8];
 } __attribute__ ((packed));
@@ -376,17 +385,32 @@ struct hci_cp_change_conn_link_key {
 } __attribute__ ((packed));
 
 #define OCF_READ_REMOTE_FEATURES 0x001B
-struct hci_cp_read_rmt_features {
+struct hci_cp_read_remote_features {
         __le16   handle;
 } __attribute__ ((packed));
 
 #define OCF_READ_REMOTE_VERSION 0x001D
-struct hci_cp_read_rmt_version {
+struct hci_cp_read_remote_version {
         __le16   handle;
 } __attribute__ ((packed));
 
 /* Link Policy */
-#define OGF_LINK_POLICY  0x02   
+#define OGF_LINK_POLICY 0x02   
+
+#define OCF_SNIFF_MODE          0x0003
+struct hci_cp_sniff_mode {
+        __le16   handle;
+        __le16   max_interval;
+        __le16   min_interval;
+        __le16   attempt;
+        __le16   timeout;
+} __attribute__ ((packed));
+
+#define OCF_EXIT_SNIFF_MODE     0x0004
+struct hci_cp_exit_sniff_mode {
+        __le16   handle;
+} __attribute__ ((packed));
+
 #define OCF_ROLE_DISCOVERY      0x0009
 struct hci_cp_role_discovery {
         __le16   handle;
@@ -407,7 +431,7 @@ struct hci_rp_read_link_policy {
         __le16   policy;
 } __attribute__ ((packed));
 
-#define OCF_SWITCH_ROLE 0x000B
+#define OCF_SWITCH_ROLE         0x000B
 struct hci_cp_switch_role {
         bdaddr_t bdaddr;
         __u8     role;
@@ -423,6 +447,14 @@ struct hci_rp_write_link_policy {
         __le16   handle;
 } __attribute__ ((packed));
 
+#define OCF_SNIFF_SUBRATE       0x0011
+struct hci_cp_sniff_subrate {
+        __le16   handle;
+        __le16   max_latency;
+        __le16   min_remote_timeout;
+        __le16   min_local_timeout;
+} __attribute__ ((packed));
+
 /* Status params */
 #define OGF_STATUS_PARAM        0x05
 
@@ -582,15 +614,15 @@ struct hci_ev_link_key_notify {
         __u8     key_type;
 } __attribute__ ((packed));
 
-#define HCI_EV_RMT_FEATURES     0x0B
-struct hci_ev_rmt_features {
+#define HCI_EV_REMOTE_FEATURES  0x0B
+struct hci_ev_remote_features {
         __u8     status;
         __le16   handle;
         __u8     features[8];
 } __attribute__ ((packed));
 
-#define HCI_EV_RMT_VERSION      0x0C
-struct hci_ev_rmt_version {
+#define HCI_EV_REMOTE_VERSION   0x0C
+struct hci_ev_remote_version {
         __u8     status;
         __le16   handle;
         __u8     lmp_ver;
@@ -611,6 +643,16 @@ struct hci_ev_pscan_rep_mode {
         __u8     pscan_rep_mode;
 } __attribute__ ((packed));
 
+#define HCI_EV_SNIFF_SUBRATE    0x2E
+struct hci_ev_sniff_subrate {
+        __u8     status;
+        __le16   handle;
+        __le16   max_tx_latency;
+        __le16   max_rx_latency;
+        __le16   max_remote_timeout;
+        __le16   max_local_timeout;
+} __attribute__ ((packed));
+
 /* Internal events generated by Bluetooth stack */
 #define HCI_EV_STACK_INTERNAL   0xFD
 struct hci_ev_stack_internal {
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index bb9f81dc8723..f6852707bd64 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -31,10 +31,7 @@
 #define HCI_PROTO_L2CAP 0
 #define HCI_PROTO_SCO   1
 
-#define HCI_INIT_TIMEOUT (HZ * 10)
-
 /* HCI Core structures */
-
 struct inquiry_data {
         bdaddr_t        bdaddr;
         __u8            pscan_rep_mode;
@@ -81,6 +78,10 @@ struct hci_dev {
         __u16           link_policy;
         __u16           link_mode;
 
+        __u32           idle_timeout;
+        __u16           sniff_min_interval;
+        __u16           sniff_max_interval;
+
         unsigned long   quirks;
 
         atomic_t        cmd_cnt;
@@ -145,18 +146,24 @@ struct hci_conn {
         bdaddr_t         dst;
         __u16            handle;
         __u16            state;
+        __u8             mode;
         __u8             type;
         __u8             out;
         __u8             dev_class[3];
+        __u8             features[8];
+        __u16            interval;
+        __u16            link_policy;
         __u32            link_mode;
+        __u8             power_save;
         unsigned long    pend;
-        
+
         unsigned int     sent;
-        
+
         struct sk_buff_head data_q;
 
-        struct timer_list timer;
-        
+        struct timer_list disc_timer;
+        struct timer_list idle_timer;
+
         struct hci_dev  *hdev;
         void            *l2cap_data;
         void            *sco_data;
@@ -211,7 +218,8 @@ void hci_inquiry_cache_update(struct hci_dev *hdev, struct inquiry_data *data);
 enum {
         HCI_CONN_AUTH_PEND,
         HCI_CONN_ENCRYPT_PEND,
-        HCI_CONN_RSWITCH_PEND
+        HCI_CONN_RSWITCH_PEND,
+        HCI_CONN_MODE_CHANGE_PEND,
 };
 
 static inline void hci_conn_hash_init(struct hci_dev *hdev)
@@ -286,31 +294,27 @@ int hci_conn_encrypt(struct hci_conn *conn);
 int hci_conn_change_link_key(struct hci_conn *conn);
 int hci_conn_switch_role(struct hci_conn *conn, uint8_t role);
 
-static inline void hci_conn_set_timer(struct hci_conn *conn, unsigned long timeout)
-{
-        mod_timer(&conn->timer, jiffies + timeout);
-}
-
-static inline void hci_conn_del_timer(struct hci_conn *conn)
-{
-        del_timer(&conn->timer);
-}
+void hci_conn_enter_active_mode(struct hci_conn *conn);
+void hci_conn_enter_sniff_mode(struct hci_conn *conn);
 
 static inline void hci_conn_hold(struct hci_conn *conn)
 {
         atomic_inc(&conn->refcnt);
-        hci_conn_del_timer(conn);
+        del_timer(&conn->disc_timer);
 }
 
 static inline void hci_conn_put(struct hci_conn *conn)
 {
         if (atomic_dec_and_test(&conn->refcnt)) {
+                unsigned long timeo;
                 if (conn->type == ACL_LINK) {
-                        unsigned long timeo = (conn->out) ?
-                                HCI_DISCONN_TIMEOUT : HCI_DISCONN_TIMEOUT * 2;
-                        hci_conn_set_timer(conn, timeo);
+                        timeo = msecs_to_jiffies(HCI_DISCONN_TIMEOUT);
+                        if (!conn->out)
+                                timeo *= 2;
+                        del_timer(&conn->idle_timer);
                 } else
-                        hci_conn_set_timer(conn, HZ / 100);
+                        timeo = msecs_to_jiffies(10);
+                mod_timer(&conn->disc_timer, jiffies + timeo);
         }
 }
 
@@ -411,8 +415,10 @@ void hci_unregister_sysfs(struct hci_dev *hdev);
 #define SET_HCIDEV_DEV(hdev, pdev) ((hdev)->class_dev.dev = (pdev))
 
 /* ----- LMP capabilities ----- */
-#define lmp_rswitch_capable(dev) (dev->features[0] & LMP_RSWITCH)
-#define lmp_encrypt_capable(dev) (dev->features[0] & LMP_ENCRYPT)
+#define lmp_rswitch_capable(dev)   ((dev)->features[0] & LMP_RSWITCH)
+#define lmp_encrypt_capable(dev)   ((dev)->features[0] & LMP_ENCRYPT)
+#define lmp_sniff_capable(dev)     ((dev)->features[0] & LMP_SNIFF)
+#define lmp_sniffsubr_capable(dev) ((dev)->features[5] & LMP_SNIFF_SUBR)
 
 /* ----- HCI protocols ----- */
 struct hci_proto {