diff options
Diffstat (limited to 'drivers/nfc/st95hf/spi.c')
| -rw-r--r-- | drivers/nfc/st95hf/spi.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/nfc/st95hf/spi.c b/drivers/nfc/st95hf/spi.c new file mode 100644 index 0000000..e2d3bbc --- /dev/null +++ b/drivers/nfc/st95hf/spi.c @@ -0,0 +1,167 @@ +/* + * ---------------------------------------------------------------------------- + * drivers/nfc/st95hf/spi.c function definitions for SPI communication + * ---------------------------------------------------------------------------- + * Copyright (C) 2015 STMicroelectronics Pvt. Ltd. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "spi.h" + +/* Function to send user provided buffer to ST95HF through SPI */ +int st95hf_spi_send(struct st95hf_spi_context *spicontext, + unsigned char *buffertx, + int datalen, + enum req_type reqtype) +{ + struct spi_message m; + int result = 0; + struct spi_device *spidev = spicontext->spidev; + struct spi_transfer tx_transfer = { + .tx_buf = buffertx, + .len = datalen, + }; + + mutex_lock(&spicontext->spi_lock); + + if (reqtype == SYNC) { + spicontext->req_issync = true; + reinit_completion(&spicontext->done); + } else { + spicontext->req_issync = false; + } + + spi_message_init(&m); + spi_message_add_tail(&tx_transfer, &m); + + result = spi_sync(spidev, &m); + if (result) { + dev_err(&spidev->dev, "error: sending cmd to st95hf using SPI = %d\n", + result); + mutex_unlock(&spicontext->spi_lock); + return result; + } + + /* return for asynchronous or no-wait case */ + if (reqtype == ASYNC) { + mutex_unlock(&spicontext->spi_lock); + return 0; + } + + result = wait_for_completion_timeout(&spicontext->done, + msecs_to_jiffies(1000)); + /* check for timeout or success */ + if (!result) { + dev_err(&spidev->dev, "error: response not ready timeout\n"); + result = -ETIMEDOUT; + } else { + result = 0; + } + + mutex_unlock(&spicontext->spi_lock); + + return result; +} +EXPORT_SYMBOL_GPL(st95hf_spi_send); + +/* Function to Receive command Response */ +int st95hf_spi_recv_response(struct st95hf_spi_context *spicontext, + unsigned char *receivebuff) +{ + int len = 0; + struct spi_transfer tx_takedata; + struct spi_message m; + struct spi_device *spidev = spicontext->spidev; + unsigned char readdata_cmd = ST95HF_COMMAND_RECEIVE; + struct spi_transfer t[2] = { + {.tx_buf = &readdata_cmd, .len = 1,}, + {.rx_buf = receivebuff, .len = 2, .cs_change = 1,}, + }; + + int ret = 0; + + memset(&tx_takedata, 0x0, sizeof(struct spi_transfer)); + + mutex_lock(&spicontext->spi_lock); + + /* First spi transfer to know the length of valid data */ + spi_message_init(&m); + spi_message_add_tail(&t[0], &m); + spi_message_add_tail(&t[1], &m); + + ret = spi_sync(spidev, &m); + if (ret) { + dev_err(&spidev->dev, "spi_recv_resp, data length error = %d\n", + ret); + mutex_unlock(&spicontext->spi_lock); + return ret; + } + + /* As 2 bytes are already read */ + len = 2; + + /* Support of long frame */ + if (receivebuff[0] & 0x60) + len += (((receivebuff[0] & 0x60) >> 5) << 8) | receivebuff[1]; + else + len += receivebuff[1]; + + /* Now make a transfer to read only relevant bytes */ + tx_takedata.rx_buf = &receivebuff[2]; + tx_takedata.len = len - 2; + + spi_message_init(&m); + spi_message_add_tail(&tx_takedata, &m); + + ret = spi_sync(spidev, &m); + + mutex_unlock(&spicontext->spi_lock); + if (ret) { + dev_err(&spidev->dev, "spi_recv_resp, data read error = %d\n", + ret); + return ret; + } + + return len; +} +EXPORT_SYMBOL_GPL(st95hf_spi_recv_response); + +int st95hf_spi_recv_echo_res(struct st95hf_spi_context *spicontext, + unsigned char *receivebuff) +{ + unsigned char readdata_cmd = ST95HF_COMMAND_RECEIVE; + struct spi_transfer t[2] = { + {.tx_buf = &readdata_cmd, .len = 1,}, + {.rx_buf = receivebuff, .len = 1,}, + }; + struct spi_message m; + struct spi_device *spidev = spicontext->spidev; + int ret = 0; + + mutex_lock(&spicontext->spi_lock); + + spi_message_init(&m); + spi_message_add_tail(&t[0], &m); + spi_message_add_tail(&t[1], &m); + ret = spi_sync(spidev, &m); + + mutex_unlock(&spicontext->spi_lock); + + if (ret) + dev_err(&spidev->dev, "recv_echo_res, data read error = %d\n", + ret); + + return ret; +} +EXPORT_SYMBOL_GPL(st95hf_spi_recv_echo_res); |