/* * Copyright (C) 2010 NXP Semiconductors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * \file phDalNfc_uart.c * \brief DAL com port implementation for linux * * Project: Trusted NFC Linux Lignt * * $Date: 07 aug 2009 * $Author: Jonathan roux * $Revision: 1.0 $ * */ #define LOG_TAG "NFC_uart" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(ANDROID) #include #include // for property_get #endif typedef struct { int nHandle; char nOpened; struct termios nIoConfigBackup; struct termios nIoConfig; } phDal4Nfc_ComPortContext_t; /*----------------------------------------------------------------------------------- COM PORT CONFIGURATION ------------------------------------------------------------------------------------*/ #define DAL_BAUD_RATE B115200 /*----------------------------------------------------------------------------------- VARIABLES ------------------------------------------------------------------------------------*/ static phDal4Nfc_ComPortContext_t gComPortContext; /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_set_open_from_handle PURPOSE: Initialize internal variables -----------------------------------------------------------------------------*/ void phDal4Nfc_uart_initialize(void) { memset(&gComPortContext, 0, sizeof(phDal4Nfc_ComPortContext_t)); } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_set_open_from_handle PURPOSE: The application could have opened the link itself. So we just need to get the handle and consider that the open operation has already been done. -----------------------------------------------------------------------------*/ void phDal4Nfc_uart_set_open_from_handle(phHal_sHwReference_t * pDalHwContext) { gComPortContext.nHandle = (int) pDalHwContext->p_board_driver; DAL_ASSERT_STR(gComPortContext.nHandle >= 0, "Bad passed com port handle"); gComPortContext.nOpened = 1; } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_is_opened PURPOSE: Returns if the link is opened or not. (0 = not opened; 1 = opened) -----------------------------------------------------------------------------*/ int phDal4Nfc_uart_is_opened(void) { return gComPortContext.nOpened; } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_flush PURPOSE: Flushes the link ; clears the link buffers -----------------------------------------------------------------------------*/ void phDal4Nfc_uart_flush(void) { int ret; /* flushes the com port */ ret = tcflush(gComPortContext.nHandle, TCIFLUSH); DAL_ASSERT_STR(ret!=-1, "tcflush failed"); } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_close PURPOSE: Closes the link -----------------------------------------------------------------------------*/ void phDal4Nfc_uart_close(void) { if (gComPortContext.nOpened == 1) { close(gComPortContext.nHandle); gComPortContext.nHandle = 0; gComPortContext.nOpened = 0; } } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_close PURPOSE: Closes the link -----------------------------------------------------------------------------*/ NFCSTATUS phDal4Nfc_uart_open_and_configure(pphDal4Nfc_sConfig_t pConfig, void ** pLinkHandle) { int nComStatus; NFCSTATUS nfcret = NFCSTATUS_SUCCESS; int ret; DAL_ASSERT_STR(gComPortContext.nOpened==0, "Trying to open but already done!"); srand(time(NULL)); /* open communication port handle */ gComPortContext.nHandle = open(pConfig->deviceNode, O_RDWR | O_NOCTTY); if (gComPortContext.nHandle < 0) { *pLinkHandle = NULL; return PHNFCSTVAL(CID_NFC_DAL, NFCSTATUS_INVALID_DEVICE); } gComPortContext.nOpened = 1; *pLinkHandle = (void*)gComPortContext.nHandle; /* * Now configure the com port */ ret = tcgetattr(gComPortContext.nHandle, &gComPortContext.nIoConfigBackup); /* save the old io config */ if (ret == -1) { /* tcgetattr failed -- it is likely that the provided port is invalid */ *pLinkHandle = NULL; return PHNFCSTVAL(CID_NFC_DAL, NFCSTATUS_INVALID_DEVICE); } ret = fcntl(gComPortContext.nHandle, F_SETFL, 0); /* Makes the read blocking (default). */ DAL_ASSERT_STR(ret != -1, "fcntl failed"); /* Configures the io */ memset((void *)&gComPortContext.nIoConfig, (int)0, (size_t)sizeof(struct termios)); /* BAUDRATE: Set bps rate. You could also use cfsetispeed and cfsetospeed. CRTSCTS : output hardware flow control (only used if the cable has all necessary lines. See sect. 7 of Serial-HOWTO) CS8 : 8n1 (8bit,no parity,1 stopbit) CLOCAL : local connection, no modem contol CREAD : enable receiving characters */ gComPortContext.nIoConfig.c_cflag = DAL_BAUD_RATE | CS8 | CLOCAL | CREAD; /* Control mode flags */ gComPortContext.nIoConfig.c_iflag = IGNPAR; /* Input mode flags : IGNPAR Ignore parity errors */ gComPortContext.nIoConfig.c_oflag = 0; /* Output mode flags */ gComPortContext.nIoConfig.c_lflag = 0; /* Local mode flags. Read mode : non canonical, no echo */ gComPortContext.nIoConfig.c_cc[VTIME] = 0; /* Control characters. No inter-character timer */ gComPortContext.nIoConfig.c_cc[VMIN] = 1; /* Control characters. Read is blocking until X characters are read */ /* TCSANOW Make changes now without waiting for data to complete TCSADRAIN Wait until everything has been transmitted TCSAFLUSH Flush input and output buffers and make the change */ ret = tcsetattr(gComPortContext.nHandle, TCSANOW, &gComPortContext.nIoConfig); DAL_ASSERT_STR(ret != -1, "tcsetattr failed"); /* On linux the DTR signal is set by default. That causes a problem for pn544 chip because this signal is connected to "reset". So we clear it. (on windows it is cleared by default). */ ret = ioctl(gComPortContext.nHandle, TIOCMGET, &nComStatus); DAL_ASSERT_STR(ret != -1, "ioctl TIOCMGET failed"); nComStatus &= ~TIOCM_DTR; ret = ioctl(gComPortContext.nHandle, TIOCMSET, &nComStatus); DAL_ASSERT_STR(ret != -1, "ioctl TIOCMSET failed"); DAL_DEBUG("Com port status=%d\n", nComStatus); usleep(10000); /* Mandatory sleep so that the DTR line is ready before continuing */ return nfcret; } /* adb shell setprop debug.nfc.UART_ERROR_RATE X will corrupt and drop bytes in uart_read(), to test the error handling of DAL & LLC errors. */ int property_error_rate = 0; static void read_property() { char value[PROPERTY_VALUE_MAX]; property_get("debug.nfc.UART_ERROR_RATE", value, "0"); property_error_rate = atoi(value); } /* returns length of buffer after errors */ static int apply_errors(uint8_t *buffer, int length) { int i; if (!property_error_rate) return length; for (i = 0; i < length; i++) { if (rand() % 1000 < property_error_rate) { if (rand() % 2) { // 50% chance of dropping byte length--; memcpy(&buffer[i], &buffer[i+1], length-i); ALOGW("dropped byte %d", i); } else { // 50% chance of corruption buffer[i] = (uint8_t)rand(); ALOGW("corrupted byte %d", i); } } } return length; } static struct timeval timeval_remaining(struct timespec timeout) { struct timespec now; struct timeval delta; clock_gettime(CLOCK_MONOTONIC, &now); delta.tv_sec = timeout.tv_sec - now.tv_sec; delta.tv_usec = (timeout.tv_nsec - now.tv_nsec) / (long)1000; if (delta.tv_usec < 0) { delta.tv_usec += 1000000; delta.tv_sec--; } if (delta.tv_sec < 0) { delta.tv_sec = 0; delta.tv_usec = 0; } return delta; } static int libnfc_firmware_mode = 0; /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_read PURPOSE: Reads nNbBytesToRead bytes and writes them in pBuffer. Returns the number of bytes really read or -1 in case of error. -----------------------------------------------------------------------------*/ int phDal4Nfc_uart_read(uint8_t * pBuffer, int nNbBytesToRead) { int ret; int numRead = 0; struct timeval tv; struct timeval *ptv; struct timespec timeout; fd_set rfds; DAL_ASSERT_STR(gComPortContext.nOpened == 1, "read called but not opened!"); DAL_DEBUG("_uart_read() called to read %d bytes", nNbBytesToRead); read_property(); // Read timeout: // FW mode: 10s timeout // 1 byte read: steady-state LLC length read, allowed to block forever // >1 byte read: LLC payload, 100ms timeout (before pn544 re-transmit) if (nNbBytesToRead > 1 && !libnfc_firmware_mode) { clock_gettime(CLOCK_MONOTONIC, &timeout); timeout.tv_nsec += 100000000; if (timeout.tv_nsec > 1000000000) { timeout.tv_sec++; timeout.tv_nsec -= 1000000000; } ptv = &tv; } else if (libnfc_firmware_mode) { clock_gettime(CLOCK_MONOTONIC, &timeout); timeout.tv_sec += 10; ptv = &tv; } else { ptv = NULL; } while (numRead < nNbBytesToRead) { FD_ZERO(&rfds); FD_SET(gComPortContext.nHandle, &rfds); if (ptv) { tv = timeval_remaining(timeout); ptv = &tv; } ret = select(gComPortContext.nHandle + 1, &rfds, NULL, NULL, ptv); if (ret < 0) { DAL_DEBUG("select() errno=%d", errno); if (errno == EINTR || errno == EAGAIN) { continue; } return -1; } else if (ret == 0) { ALOGW("timeout!"); break; // return partial response } ret = read(gComPortContext.nHandle, pBuffer + numRead, nNbBytesToRead - numRead); if (ret > 0) { ret = apply_errors(pBuffer + numRead, ret); DAL_DEBUG("read %d bytes", ret); numRead += ret; } else if (ret == 0) { DAL_PRINT("_uart_read() EOF"); return 0; } else { DAL_DEBUG("_uart_read() errno=%d", errno); if (errno == EINTR || errno == EAGAIN) { continue; } return -1; } } return numRead; } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_link_write PURPOSE: Writes nNbBytesToWrite bytes from pBuffer to the link Returns the number of bytes that have been wrote to the interface or -1 in case of error. -----------------------------------------------------------------------------*/ int phDal4Nfc_uart_write(uint8_t * pBuffer, int nNbBytesToWrite) { int ret; int numWrote = 0; DAL_ASSERT_STR(gComPortContext.nOpened == 1, "write called but not opened!"); DAL_DEBUG("_uart_write() called to write %d bytes\n", nNbBytesToWrite); while (numWrote < nNbBytesToWrite) { ret = write(gComPortContext.nHandle, pBuffer + numWrote, nNbBytesToWrite - numWrote); if (ret > 0) { DAL_DEBUG("wrote %d bytes", ret); numWrote += ret; } else if (ret == 0) { DAL_PRINT("_uart_write() EOF"); return -1; } else { DAL_DEBUG("_uart_write() errno=%d", errno); if (errno == EINTR || errno == EAGAIN) { continue; } return -1; } } return numWrote; } /*----------------------------------------------------------------------------- FUNCTION: phDal4Nfc_uart_reset PURPOSE: Reset the PN544, using the VEN pin -----------------------------------------------------------------------------*/ int phDal4Nfc_uart_reset(long level) { static const char NFC_POWER_PATH[] = "/sys/devices/platform/nfc-power/nfc_power"; int sz; int fd = -1; int ret = NFCSTATUS_FAILED; char buffer[2]; DAL_DEBUG("phDal4Nfc_uart_reset, VEN level = %ld", level); if (snprintf(buffer, sizeof(buffer), "%u", (unsigned int)level) != 1) { ALOGE("Bad nfc power level (%u)", (unsigned int)level); goto out; } fd = open(NFC_POWER_PATH, O_WRONLY); if (fd < 0) { ALOGE("open(%s) for write failed: %s (%d)", NFC_POWER_PATH, strerror(errno), errno); goto out; } sz = write(fd, &buffer, sizeof(buffer) - 1); if (sz < 0) { ALOGE("write(%s) failed: %s (%d)", NFC_POWER_PATH, strerror(errno), errno); goto out; } ret = NFCSTATUS_SUCCESS; if (level == 2) { libnfc_firmware_mode = 1; } else { libnfc_firmware_mode = 0; } out: if (fd >= 0) { close(fd); } return ret; }