/**************************************************************************** * apps/system/i2c/i2c_devif.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "i2ctool.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /* Device naming */ #define DEVNAME_FMT "/dev/i2c%d" #define DEVNAME_FMTLEN (8 + 3 + 1) /**************************************************************************** * Private Data ****************************************************************************/ static char g_devname[DEVNAME_FMTLEN]; /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: i2cdev_path ****************************************************************************/ FAR char *i2cdev_path(int bus) { snprintf(g_devname, DEVNAME_FMTLEN, DEVNAME_FMT, bus); return g_devname; } /**************************************************************************** * Name: i2cdev_exists ****************************************************************************/ bool i2cdev_exists(int bus) { struct stat buf; FAR char *devpath; int ret; /* Get the device path */ devpath = i2cdev_path(bus); /* Check if something exists at that path */ ret = stat(devpath, &buf); if (ret >= 0) { /* Return TRUE only if it is a character driver */ if (S_ISCHR(buf.st_mode)) { return true; } } return false; } /**************************************************************************** * Name: i2cdev_open ****************************************************************************/ int i2cdev_open(int bus) { FAR char *devpath; /* Get the device path */ devpath = i2cdev_path(bus); /* Open the file for read-only access (we need only IOCTLs) */ return open(devpath, O_RDONLY); } /**************************************************************************** * Name: i2cdev_transfer ****************************************************************************/ int i2cdev_transfer(int fd, FAR struct i2c_msg_s *msgv, int msgc) { struct i2c_transfer_s xfer; /* Set up the IOCTL argument */ xfer.msgv = msgv; xfer.msgc = msgc; /* Perform the IOCTL */ return ioctl(fd, I2CIOC_TRANSFER, (unsigned long)((uintptr_t)&xfer)); } /**************************************************************************** * Name: i2cdev_reset ****************************************************************************/ #ifdef CONFIG_I2C_RESET int i2cdev_reset(int fd) { /* Perform the IOCTL */ return ioctl(fd, I2CIOC_RESET, 0); } #endif