spi.c: added context validity checks

Signed-off-by: Alex Tereschenko <alext.mkrs@gmail.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/spi/spi.c

@@ -181,6 +181,11 @@ mraa_spi_init_raw(unsigned int bus, unsigned int cs)
 mraa_result_t
 mraa_spi_mode(mraa_spi_context dev, mraa_spi_mode_t mode)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: mode: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     uint8_t spi_mode = 0;
     switch (mode) {
         case MRAA_SPI_MODE0:
@@ -212,6 +217,11 @@ mraa_spi_mode(mraa_spi_context dev, mraa_spi_mode_t mode)
 mraa_result_t
 mraa_spi_frequency(mraa_spi_context dev, int hz)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: frequency: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     int speed = 0;
     dev->clock = hz;
     if (ioctl(dev->devfd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) != -1) {
@@ -226,6 +236,11 @@ mraa_spi_frequency(mraa_spi_context dev, int hz)
 mraa_result_t
 mraa_spi_lsbmode(mraa_spi_context dev, mraa_boolean_t lsb)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: lsbmode: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     if (IS_FUNC_DEFINED(dev, spi_lsbmode_replace)) {
         return dev->advance_func->spi_lsbmode_replace(dev, lsb);
     }
@@ -246,6 +261,11 @@ mraa_spi_lsbmode(mraa_spi_context dev, mraa_boolean_t lsb)
 mraa_result_t
 mraa_spi_bit_per_word(mraa_spi_context dev, unsigned int bits)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: bit_per_word: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     if (ioctl(dev->devfd, SPI_IOC_WR_BITS_PER_WORD, &bits) < 0) {
         syslog(LOG_ERR, "spi: Failed to set bit per word");
         return MRAA_ERROR_INVALID_RESOURCE;
@@ -257,6 +277,11 @@ mraa_spi_bit_per_word(mraa_spi_context dev, unsigned int bits)
 int
 mraa_spi_write(mraa_spi_context dev, uint8_t data)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: write: context is invalid");
+        return -1;
+    }
+
     struct spi_ioc_transfer msg;
     memset(&msg, 0, sizeof(msg));
 
@@ -279,6 +304,11 @@ mraa_spi_write(mraa_spi_context dev, uint8_t data)
 int
 mraa_spi_write_word(mraa_spi_context dev, uint16_t data)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: write_word: context is invalid");
+        return -1;
+    }
+
     struct spi_ioc_transfer msg;
     memset(&msg, 0, sizeof(msg));
 
@@ -301,6 +331,11 @@ mraa_spi_write_word(mraa_spi_context dev, uint16_t data)
 mraa_result_t
 mraa_spi_transfer_buf(mraa_spi_context dev, uint8_t* data, uint8_t* rxbuf, int length)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: transfer_buf: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     struct spi_ioc_transfer msg;
     memset(&msg, 0, sizeof(msg));
 
@@ -320,6 +355,11 @@ mraa_spi_transfer_buf(mraa_spi_context dev, uint8_t* data, uint8_t* rxbuf, int l
 mraa_result_t
 mraa_spi_transfer_buf_word(mraa_spi_context dev, uint16_t* data, uint16_t* rxbuf, int length)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: transfer_buf_word: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     struct spi_ioc_transfer msg;
     memset(&msg, 0, sizeof(msg));
 
@@ -339,6 +379,11 @@ mraa_spi_transfer_buf_word(mraa_spi_context dev, uint16_t* data, uint16_t* rxbuf
 uint8_t*
 mraa_spi_write_buf(mraa_spi_context dev, uint8_t* data, int length)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: write_buf: context is invalid");
+        return NULL;
+    }
+
     uint8_t* recv = malloc(sizeof(uint8_t) * length);
 
     if (mraa_spi_transfer_buf(dev, data, recv, length) != MRAA_SUCCESS) {
@@ -351,6 +396,11 @@ mraa_spi_write_buf(mraa_spi_context dev, uint8_t* data, int length)
 uint16_t*
 mraa_spi_write_buf_word(mraa_spi_context dev, uint16_t* data, int length)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: write_buf_word: context is invalid");
+        return NULL;
+    }
+
     uint16_t* recv = malloc(sizeof(uint16_t) * length);
 
     if (mraa_spi_transfer_buf_word(dev, data, recv, length) != MRAA_SUCCESS) {
@@ -363,6 +413,11 @@ mraa_spi_write_buf_word(mraa_spi_context dev, uint16_t* data, int length)
 mraa_result_t
 mraa_spi_stop(mraa_spi_context dev)
 {
+    if (dev == NULL) {
+        syslog(LOG_ERR, "spi: stop: context is invalid");
+        return MRAA_ERROR_INVALID_HANDLE;
+    }
+
     close(dev->devfd);
     free(dev);
     return MRAA_SUCCESS;