drivers/nfc/nfcwilink.c

   1 /*
   2  *  Texas Instrument's NFC Driver For Shared Transport.
   3  *
   4  *  NFC Driver acts as interface between NCI core and
   5  *  TI Shared Transport Layer.
   6  *
   7  *  Copyright (C) 2011 Texas Instruments, Inc.
   8  *
   9  *  Written by Ilan Elias <ilane@ti.com>
  10  *
  11  *  Acknowledgements:
  12  *  This file is based on btwilink.c, which was written
  13  *  by Raja Mani and Pavan Savoy.
  14  *
  15  *  This program is free software; you can redistribute it and/or modify
  16  *  it under the terms of the GNU General Public License version 2 as
  17  *  published by the Free Software Foundation.
  18  *
  19  *  This program is distributed in the hope that it will be useful,
  20  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *  GNU General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License
  25  *  along with this program; if not, write to the Free Software
  26  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  27  *
  28  */
  29 #include <linux/platform_device.h>
  30 #include <linux/module.h>
  31 #include <linux/nfc.h>
  32 #include <net/nfc/nci.h>
  33 #include <net/nfc/nci_core.h>
  34 #include <linux/ti_wilink_st.h>
  35
  36 #define NFCWILINK_CHNL                  12
  37 #define NFCWILINK_OPCODE                7
  38 #define NFCWILINK_MAX_FRAME_SIZE        300
  39 #define NFCWILINK_HDR_LEN               4
  40 #define NFCWILINK_OFFSET_LEN_IN_HDR     1
  41 #define NFCWILINK_LEN_SIZE              2
  42 #define NFCWILINK_REGISTER_TIMEOUT      8000    /* 8 sec */
  43
  44 struct nfcwilink_hdr {
  45         u8 chnl;
  46         u8 opcode;
  47         u16 len;
  48 } __packed;
  49
  50 struct nfcwilink {
  51         struct platform_device          *pdev;
  52         struct nci_dev                  *ndev;
  53         unsigned long                   flags;
  54
  55         char                            st_register_cb_status;
  56         long                            (*st_write) (struct sk_buff *);
  57         struct completion               st_register_completed;
  58 };
  59
  60 /* NFCWILINK driver flags */
  61 enum {
  62         NFCWILINK_RUNNING,
  63 };
  64
  65 /* Called by ST when registration is complete */
  66 static void nfcwilink_register_complete(void *priv_data, char data)
  67 {
  68         struct nfcwilink *drv = priv_data;
  69
  70         nfc_dev_dbg(&drv->pdev->dev, "register_complete entry");
  71
  72         /* store ST registration status */
  73         drv->st_register_cb_status = data;
  74
  75         /* complete the wait in nfc_st_open() */
  76         complete(&drv->st_register_completed);
  77 }
  78
  79 /* Called by ST when receive data is available */
  80 static long nfcwilink_receive(void *priv_data, struct sk_buff *skb)
  81 {
  82         struct nfcwilink *drv = priv_data;
  83         int rc;
  84
  85         nfc_dev_dbg(&drv->pdev->dev, "receive entry, len %d", skb->len);
  86
  87         if (!skb)
  88                 return -EFAULT;
  89
  90         if (!drv) {
  91                 kfree_skb(skb);
  92                 return -EFAULT;
  93         }
  94
  95         /* strip the ST header
  96         (apart for the chnl byte, which is not received in the hdr) */
  97         skb_pull(skb, (NFCWILINK_HDR_LEN-1));
  98
  99         skb->dev = (void *) drv->ndev;
 100
 101         /* Forward skb to NCI core layer */
 102         rc = nci_recv_frame(skb);
 103         if (rc < 0) {
 104                 nfc_dev_err(&drv->pdev->dev, "nci_recv_frame failed %d", rc);
 105                 return rc;
 106         }
 107
 108         return 0;
 109 }
 110
 111 /* protocol structure registered with ST */
 112 static struct st_proto_s nfcwilink_proto = {
 113         .chnl_id = NFCWILINK_CHNL,
 114         .max_frame_size = NFCWILINK_MAX_FRAME_SIZE,
 115         .hdr_len = (NFCWILINK_HDR_LEN-1),       /* not including chnl byte */
 116         .offset_len_in_hdr = NFCWILINK_OFFSET_LEN_IN_HDR,
 117         .len_size = NFCWILINK_LEN_SIZE,
 118         .reserve = 0,
 119         .recv = nfcwilink_receive,
 120         .reg_complete_cb = nfcwilink_register_complete,
 121         .write = NULL,
 122 };
 123
 124 static int nfcwilink_open(struct nci_dev *ndev)
 125 {
 126         struct nfcwilink *drv = nci_get_drvdata(ndev);
 127         unsigned long comp_ret;
 128         int rc;
 129
 130         nfc_dev_dbg(&drv->pdev->dev, "open entry");
 131
 132         if (test_and_set_bit(NFCWILINK_RUNNING, &drv->flags)) {
 133                 rc = -EBUSY;
 134                 goto exit;
 135         }
 136
 137         nfcwilink_proto.priv_data = drv;
 138
 139         init_completion(&drv->st_register_completed);
 140         drv->st_register_cb_status = -EINPROGRESS;
 141
 142         rc = st_register(&nfcwilink_proto);
 143         if (rc < 0) {
 144                 if (rc == -EINPROGRESS) {
 145                         comp_ret = wait_for_completion_timeout(
 146                         &drv->st_register_completed,
 147                         msecs_to_jiffies(NFCWILINK_REGISTER_TIMEOUT));
 148
 149                         nfc_dev_dbg(&drv->pdev->dev,
 150                         "wait_for_completion_timeout returned %ld",
 151                         comp_ret);
 152
 153                         if (comp_ret == 0) {
 154                                 /* timeout */
 155                                 rc = -ETIMEDOUT;
 156                                 goto clear_exit;
 157                         } else if (drv->st_register_cb_status != 0) {
 158                                 rc = drv->st_register_cb_status;
 159                                 nfc_dev_err(&drv->pdev->dev,
 160                                 "st_register_cb failed %d", rc);
 161                                 goto clear_exit;
 162                         }
 163                 } else {
 164                         nfc_dev_err(&drv->pdev->dev,
 165                                 "st_register failed %d", rc);
 166                         goto clear_exit;
 167                 }
 168         }
 169
 170         /* st_register MUST fill the write callback */
 171         BUG_ON(nfcwilink_proto.write == NULL);
 172         drv->st_write = nfcwilink_proto.write;
 173
 174         goto exit;
 175
 176 clear_exit:
 177         clear_bit(NFCWILINK_RUNNING, &drv->flags);
 178
 179 exit:
 180         return rc;
 181 }
 182
 183 static int nfcwilink_close(struct nci_dev *ndev)
 184 {
 185         struct nfcwilink *drv = nci_get_drvdata(ndev);
 186         int rc;
 187
 188         nfc_dev_dbg(&drv->pdev->dev, "close entry");
 189
 190         if (!test_and_clear_bit(NFCWILINK_RUNNING, &drv->flags))
 191                 return 0;
 192
 193         rc = st_unregister(&nfcwilink_proto);
 194         if (rc)
 195                 nfc_dev_err(&drv->pdev->dev, "st_unregister failed %d", rc);
 196
 197         drv->st_write = NULL;
 198
 199         return rc;
 200 }
 201
 202 static int nfcwilink_send(struct sk_buff *skb)
 203 {
 204         struct nci_dev *ndev = (struct nci_dev *)skb->dev;
 205         struct nfcwilink *drv = nci_get_drvdata(ndev);
 206         struct nfcwilink_hdr hdr = {NFCWILINK_CHNL, NFCWILINK_OPCODE, 0x0000};
 207         long len;
 208
 209         nfc_dev_dbg(&drv->pdev->dev, "send entry, len %d", skb->len);
 210
 211         if (!test_bit(NFCWILINK_RUNNING, &drv->flags))
 212                 return -EBUSY;
 213
 214         /* add the ST hdr to the start of the buffer */
 215         hdr.len = skb->len;
 216         memcpy(skb_push(skb, NFCWILINK_HDR_LEN), &hdr, NFCWILINK_HDR_LEN);
 217
 218         /* Insert skb to shared transport layer's transmit queue.
 219          * Freeing skb memory is taken care in shared transport layer,
 220          * so don't free skb memory here.
 221          */
 222         len = drv->st_write(skb);
 223         if (len < 0) {
 224                 kfree_skb(skb);
 225                 nfc_dev_err(&drv->pdev->dev, "st_write failed %ld", len);
 226                 return -EFAULT;
 227         }
 228
 229         return 0;
 230 }
 231
 232 static struct nci_ops nfcwilink_ops = {
 233         .open = nfcwilink_open,
 234         .close = nfcwilink_close,
 235         .send = nfcwilink_send,
 236 };
 237
 238 static int nfcwilink_probe(struct platform_device *pdev)
 239 {
 240         static struct nfcwilink *drv;
 241         int rc;
 242         u32 protocols;
 243
 244         nfc_dev_dbg(&pdev->dev, "probe entry");
 245
 246         drv = kzalloc(sizeof(struct nfcwilink), GFP_KERNEL);
 247         if (!drv) {
 248                 rc = -ENOMEM;
 249                 goto exit;
 250         }
 251
 252         drv->pdev = pdev;
 253
 254         protocols = NFC_PROTO_JEWEL_MASK
 255                         | NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
 256                         | NFC_PROTO_ISO14443_MASK
 257                         | NFC_PROTO_NFC_DEP_MASK;
 258
 259         drv->ndev = nci_allocate_device(&nfcwilink_ops,
 260                                         protocols,
 261                                         NFCWILINK_HDR_LEN,
 262                                         0);
 263         if (!drv->ndev) {
 264                 nfc_dev_err(&pdev->dev, "nci_allocate_device failed");
 265                 rc = -ENOMEM;
 266                 goto free_exit;
 267         }
 268
 269         nci_set_parent_dev(drv->ndev, &pdev->dev);
 270         nci_set_drvdata(drv->ndev, drv);
 271
 272         rc = nci_register_device(drv->ndev);
 273         if (rc < 0) {
 274                 nfc_dev_err(&pdev->dev, "nci_register_device failed %d", rc);
 275                 goto free_dev_exit;
 276         }
 277
 278         dev_set_drvdata(&pdev->dev, drv);
 279
 280         goto exit;
 281
 282 free_dev_exit:
 283         nci_free_device(drv->ndev);
 284
 285 free_exit:
 286         kfree(drv);
 287
 288 exit:
 289         return rc;
 290 }
 291
 292 static int nfcwilink_remove(struct platform_device *pdev)
 293 {
 294         struct nfcwilink *drv = dev_get_drvdata(&pdev->dev);
 295         struct nci_dev *ndev;
 296
 297         nfc_dev_dbg(&pdev->dev, "remove entry");
 298
 299         if (!drv)
 300                 return -EFAULT;
 301
 302         ndev = drv->ndev;
 303
 304         nci_unregister_device(ndev);
 305         nci_free_device(ndev);
 306
 307         kfree(drv);
 308
 309         dev_set_drvdata(&pdev->dev, NULL);
 310
 311         return 0;
 312 }
 313
 314 static struct platform_driver nfcwilink_driver = {
 315         .probe = nfcwilink_probe,
 316         .remove = nfcwilink_remove,
 317         .driver = {
 318                 .name = "nfcwilink",
 319                 .owner = THIS_MODULE,
 320         },
 321 };
 322
 323 /* ------- Module Init/Exit interfaces ------ */
 324 static int __init nfcwilink_init(void)
 325 {
 326         printk(KERN_INFO "NFC Driver for TI WiLink");
 327
 328         return platform_driver_register(&nfcwilink_driver);
 329 }
 330
 331 static void __exit nfcwilink_exit(void)
 332 {
 333         platform_driver_unregister(&nfcwilink_driver);
 334 }
 335
 336 module_init(nfcwilink_init);
 337 module_exit(nfcwilink_exit);
 338
 339 /* ------ Module Info ------ */
 340
 341 MODULE_AUTHOR("Ilan Elias <ilane@ti.com>");
 342 MODULE_DESCRIPTION("NFC Driver for TI Shared Transport");
 343 MODULE_LICENSE("GPL");