drivers/nfc/st95hf/spi.c

   1 /*
   2  * ----------------------------------------------------------------------------
   3  * drivers/nfc/st95hf/spi.c function definitions for SPI communication
   4  * ----------------------------------------------------------------------------
   5  * Copyright (C) 2015 STMicroelectronics Pvt. Ltd. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms and conditions of the GNU General Public License,
   9  * version 2, as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "spi.h"
  21
  22 /* Function to send user provided buffer to ST95HF through SPI */
  23 int st95hf_spi_send(struct st95hf_spi_context *spicontext,
  24                     unsigned char *buffertx,
  25                     int datalen,
  26                     enum req_type reqtype)
  27 {
  28         struct spi_message m;
  29         int result = 0;
  30         struct spi_device *spidev = spicontext->spidev;
  31         struct spi_transfer tx_transfer = {
  32                 .tx_buf = buffertx,
  33                 .len = datalen,
  34         };
  35
  36         mutex_lock(&spicontext->spi_lock);
  37
  38         if (reqtype == SYNC) {
  39                 spicontext->req_issync = true;
  40                 reinit_completion(&spicontext->done);
  41         } else {
  42                 spicontext->req_issync = false;
  43         }
  44
  45         spi_message_init(&m);
  46         spi_message_add_tail(&tx_transfer, &m);
  47
  48         result = spi_sync(spidev, &m);
  49         if (result) {
  50                 dev_err(&spidev->dev, "error: sending cmd to st95hf using SPI = %d\n",
  51                         result);
  52                 mutex_unlock(&spicontext->spi_lock);
  53                 return result;
  54         }
  55
  56         /* return for asynchronous or no-wait case */
  57         if (reqtype == ASYNC) {
  58                 mutex_unlock(&spicontext->spi_lock);
  59                 return 0;
  60         }
  61
  62         result = wait_for_completion_timeout(&spicontext->done,
  63                                              msecs_to_jiffies(1000));
  64         /* check for timeout or success */
  65         if (!result) {
  66                 dev_err(&spidev->dev, "error: response not ready timeout\n");
  67                 result = -ETIMEDOUT;
  68         } else {
  69                 result = 0;
  70         }
  71
  72         mutex_unlock(&spicontext->spi_lock);
  73
  74         return result;
  75 }
  76 EXPORT_SYMBOL_GPL(st95hf_spi_send);
  77
  78 /* Function to Receive command Response */
  79 int st95hf_spi_recv_response(struct st95hf_spi_context *spicontext,
  80                              unsigned char *receivebuff)
  81 {
  82         int len = 0;
  83         struct spi_transfer tx_takedata;
  84         struct spi_message m;
  85         struct spi_device *spidev = spicontext->spidev;
  86         unsigned char readdata_cmd = ST95HF_COMMAND_RECEIVE;
  87         struct spi_transfer t[2] = {
  88                 {.tx_buf = &readdata_cmd, .len = 1,},
  89                 {.rx_buf = receivebuff, .len = 2, .cs_change = 1,},
  90         };
  91
  92         int ret = 0;
  93
  94         memset(&tx_takedata, 0x0, sizeof(struct spi_transfer));
  95
  96         mutex_lock(&spicontext->spi_lock);
  97
  98         /* First spi transfer to know the length of valid data */
  99         spi_message_init(&m);
 100         spi_message_add_tail(&t[0], &m);
 101         spi_message_add_tail(&t[1], &m);
 102
 103         ret = spi_sync(spidev, &m);
 104         if (ret) {
 105                 dev_err(&spidev->dev, "spi_recv_resp, data length error = %d\n",
 106                         ret);
 107                 mutex_unlock(&spicontext->spi_lock);
 108                 return ret;
 109         }
 110
 111         /* As 2 bytes are already read */
 112         len = 2;
 113
 114         /* Support of long frame */
 115         if (receivebuff[0] & 0x60)
 116                 len += (((receivebuff[0] & 0x60) >> 5) << 8) | receivebuff[1];
 117         else
 118                 len += receivebuff[1];
 119
 120         /* Now make a transfer to read only relevant bytes */
 121         tx_takedata.rx_buf = &receivebuff[2];
 122         tx_takedata.len = len - 2;
 123
 124         spi_message_init(&m);
 125         spi_message_add_tail(&tx_takedata, &m);
 126
 127         ret = spi_sync(spidev, &m);
 128
 129         mutex_unlock(&spicontext->spi_lock);
 130         if (ret) {
 131                 dev_err(&spidev->dev, "spi_recv_resp, data read error = %d\n",
 132                         ret);
 133                 return ret;
 134         }
 135
 136         return len;
 137 }
 138 EXPORT_SYMBOL_GPL(st95hf_spi_recv_response);
 139
 140 int st95hf_spi_recv_echo_res(struct st95hf_spi_context *spicontext,
 141                              unsigned char *receivebuff)
 142 {
 143         unsigned char readdata_cmd = ST95HF_COMMAND_RECEIVE;
 144         struct spi_transfer t[2] = {
 145                 {.tx_buf = &readdata_cmd, .len = 1,},
 146                 {.rx_buf = receivebuff, .len = 1,},
 147         };
 148         struct spi_message m;
 149         struct spi_device *spidev = spicontext->spidev;
 150         int ret = 0;
 151
 152         mutex_lock(&spicontext->spi_lock);
 153
 154         spi_message_init(&m);
 155         spi_message_add_tail(&t[0], &m);
 156         spi_message_add_tail(&t[1], &m);
 157         ret = spi_sync(spidev, &m);
 158
 159         mutex_unlock(&spicontext->spi_lock);
 160
 161         if (ret)
 162                 dev_err(&spidev->dev, "recv_echo_res, data read error = %d\n",
 163                         ret);
 164
 165         return ret;
 166 }
 167 EXPORT_SYMBOL_GPL(st95hf_spi_recv_echo_res);