diff options
| -rw-r--r-- | i2c_helper_linux.c | 29 |
1 files changed, 9 insertions, 20 deletions
diff --git a/i2c_helper_linux.c b/i2c_helper_linux.c index 5c191f92..9383c857 100644 --- a/i2c_helper_linux.c +++ b/i2c_helper_linux.c @@ -28,7 +28,8 @@ #include "flash.h" #include "i2c_helper.h" -#define I2C_DEV_PREFIX "/dev/i2c-" +/* Null characters are placeholders for bus number digits */ +#define I2C_DEV_PREFIX "/dev/i2c-\0\0\0" #define I2C_MAX_BUS 255 int i2c_close(int fd) @@ -38,11 +39,11 @@ int i2c_close(int fd) int i2c_open(int bus, uint16_t addr, int force) { + char dev[sizeof(I2C_DEV_PREFIX)] = {0}; + int ret = -1; int fd = -1; - /* Maximum i2c bus number is 255(3 char), +1 for null terminated string. */ - int path_len = strlen(I2C_DEV_PREFIX) + 4; int request = force ? I2C_SLAVE_FORCE : I2C_SLAVE; if (bus < 0 || bus > I2C_MAX_BUS) { @@ -50,38 +51,26 @@ int i2c_open(int bus, uint16_t addr, int force) return ret; } - char *dev = calloc(1, path_len); - if (!dev) { - msg_perr("Unable to allocate space for device name of len %d: %s.\n", - path_len, strerror(errno)); - goto linux_i2c_open_err; - } - - ret = snprintf(dev, path_len, "%s%d", I2C_DEV_PREFIX, bus); + ret = snprintf(dev, sizeof(dev), "%s%d", I2C_DEV_PREFIX, bus); if (ret < 0) { msg_perr("Unable to join bus number to device name: %s.\n", strerror(errno)); - goto linux_i2c_open_err; + return ret; } fd = open(dev, O_RDWR); if (fd < 0) { msg_perr("Unable to open I2C device %s: %s.\n", dev, strerror(errno)); - ret = fd; - goto linux_i2c_open_err; + return fd; } ret = ioctl(fd, request, addr); if (ret < 0) { msg_perr("Unable to set I2C slave address to 0x%02x: %s.\n", addr, strerror(errno)); i2c_close(fd); - goto linux_i2c_open_err; + return ret; } -linux_i2c_open_err: - if (dev) - free(dev); - - return ret ? ret : fd; + return fd; } int i2c_read(int fd, uint16_t addr, i2c_buffer_t *buf) |