drivers/bluetooth/btrsi.c

   1 /*
   2  * Copyright (c) 2017 Redpine Signals Inc.
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <net/bluetooth/bluetooth.h>
  19 #include <net/bluetooth/hci_core.h>
  20 #include <linux/unaligned.h>
  21 #include <net/rsi_91x.h>
  22
  23 #define RSI_DMA_ALIGN   8
  24 #define RSI_FRAME_DESC_SIZE     16
  25 #define RSI_HEADROOM_FOR_BT_HAL (RSI_FRAME_DESC_SIZE + RSI_DMA_ALIGN)
  26
  27 struct rsi_hci_adapter {
  28         void *priv;
  29         struct rsi_proto_ops *proto_ops;
  30         struct hci_dev *hdev;
  31 };
  32
  33 static int rsi_hci_open(struct hci_dev *hdev)
  34 {
  35         return 0;
  36 }
  37
  38 static int rsi_hci_close(struct hci_dev *hdev)
  39 {
  40         return 0;
  41 }
  42
  43 static int rsi_hci_flush(struct hci_dev *hdev)
  44 {
  45         return 0;
  46 }
  47
  48 static int rsi_hci_send_pkt(struct hci_dev *hdev, struct sk_buff *skb)
  49 {
  50         struct rsi_hci_adapter *h_adapter = hci_get_drvdata(hdev);
  51         struct sk_buff *new_skb = NULL;
  52
  53         switch (hci_skb_pkt_type(skb)) {
  54         case HCI_COMMAND_PKT:
  55                 hdev->stat.cmd_tx++;
  56                 break;
  57         case HCI_ACLDATA_PKT:
  58                 hdev->stat.acl_tx++;
  59                 break;
  60         case HCI_SCODATA_PKT:
  61                 hdev->stat.sco_tx++;
  62                 break;
  63         }
  64
  65         if (skb_headroom(skb) < RSI_HEADROOM_FOR_BT_HAL) {
  66                 /* Insufficient skb headroom - allocate a new skb */
  67                 new_skb = skb_realloc_headroom(skb, RSI_HEADROOM_FOR_BT_HAL);
  68                 if (unlikely(!new_skb))
  69                         return -ENOMEM;
  70                 bt_cb(new_skb)->pkt_type = hci_skb_pkt_type(skb);
  71                 kfree_skb(skb);
  72                 skb = new_skb;
  73                 if (!IS_ALIGNED((unsigned long)skb->data, RSI_DMA_ALIGN)) {
  74                         u8 *skb_data = skb->data;
  75                         int skb_len = skb->len;
  76
  77                         skb_push(skb, RSI_DMA_ALIGN);
  78                         skb_pull(skb, PTR_ALIGN(skb->data,
  79                                                 RSI_DMA_ALIGN) - skb->data);
  80                         memmove(skb->data, skb_data, skb_len);
  81                         skb_trim(skb, skb_len);
  82                 }
  83         }
  84
  85         return h_adapter->proto_ops->coex_send_pkt(h_adapter->priv, skb,
  86                                                    RSI_BT_Q);
  87 }
  88
  89 static int rsi_hci_recv_pkt(void *priv, const u8 *pkt)
  90 {
  91         struct rsi_hci_adapter *h_adapter = priv;
  92         struct hci_dev *hdev = h_adapter->hdev;
  93         struct sk_buff *skb;
  94         int pkt_len = get_unaligned_le16(pkt) & 0x0fff;
  95
  96         skb = dev_alloc_skb(pkt_len);
  97         if (!skb)
  98                 return -ENOMEM;
  99
 100         memcpy(skb->data, pkt + RSI_FRAME_DESC_SIZE, pkt_len);
 101         skb_put(skb, pkt_len);
 102         h_adapter->hdev->stat.byte_rx += skb->len;
 103
 104         hci_skb_pkt_type(skb) = pkt[14];
 105
 106         return hci_recv_frame(hdev, skb);
 107 }
 108
 109 static int rsi_hci_attach(void *priv, struct rsi_proto_ops *ops)
 110 {
 111         struct rsi_hci_adapter *h_adapter = NULL;
 112         struct hci_dev *hdev;
 113         int err = 0;
 114
 115         h_adapter = kzalloc(sizeof(*h_adapter), GFP_KERNEL);
 116         if (!h_adapter)
 117                 return -ENOMEM;
 118
 119         h_adapter->priv = priv;
 120         ops->set_bt_context(priv, h_adapter);
 121         h_adapter->proto_ops = ops;
 122
 123         hdev = hci_alloc_dev();
 124         if (!hdev) {
 125                 BT_ERR("Failed to alloc HCI device");
 126                 goto err;
 127         }
 128
 129         h_adapter->hdev = hdev;
 130
 131         if (ops->get_host_intf(priv) == RSI_HOST_INTF_SDIO)
 132                 hdev->bus = HCI_SDIO;
 133         else
 134                 hdev->bus = HCI_USB;
 135
 136         hci_set_drvdata(hdev, h_adapter);
 137         hdev->open = rsi_hci_open;
 138         hdev->close = rsi_hci_close;
 139         hdev->flush = rsi_hci_flush;
 140         hdev->send = rsi_hci_send_pkt;
 141
 142         err = hci_register_dev(hdev);
 143         if (err < 0) {
 144                 BT_ERR("HCI registration failed with errcode %d", err);
 145                 hci_free_dev(hdev);
 146                 goto err;
 147         }
 148
 149         return 0;
 150 err:
 151         h_adapter->hdev = NULL;
 152         kfree(h_adapter);
 153         return -EINVAL;
 154 }
 155
 156 static void rsi_hci_detach(void *priv)
 157 {
 158         struct rsi_hci_adapter *h_adapter = priv;
 159         struct hci_dev *hdev;
 160
 161         if (!h_adapter)
 162                 return;
 163
 164         hdev = h_adapter->hdev;
 165         if (hdev) {
 166                 hci_unregister_dev(hdev);
 167                 hci_free_dev(hdev);
 168                 h_adapter->hdev = NULL;
 169         }
 170
 171         kfree(h_adapter);
 172 }
 173
 174 const struct rsi_mod_ops rsi_bt_ops = {
 175         .attach = rsi_hci_attach,
 176         .detach = rsi_hci_detach,
 177         .recv_pkt = rsi_hci_recv_pkt,
 178 };
 179 EXPORT_SYMBOL(rsi_bt_ops);
 180
 181 static int rsi_91x_bt_module_init(void)
 182 {
 183         return 0;
 184 }
 185
 186 static void rsi_91x_bt_module_exit(void)
 187 {
 188         return;
 189 }
 190
 191 module_init(rsi_91x_bt_module_init);
 192 module_exit(rsi_91x_bt_module_exit);
 193 MODULE_AUTHOR("Redpine Signals Inc");
 194 MODULE_DESCRIPTION("RSI BT driver");
 195 MODULE_LICENSE("Dual BSD/GPL");