libmraa: Fix compilation warnings about unsigned ints

Make better use of unsigned/signed ints, signed ints are preffered unless there
is a good reason not to.

Signed-off-by: Alexandru Timohi <alexandru.timohi@intel.com>
Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

api/mraa/common.h

@@ -159,7 +159,7 @@ const char* mraa_get_platform_version(int platform_offset);
  * @param priority Value from typically 0 to 99
  * @return The priority value set
  */
-int mraa_set_priority(const unsigned int priority);
+int mraa_set_priority(const int priority);
 
 /** Get the version string of mraa autogenerated from git tag
  *
@@ -214,7 +214,7 @@ int mraa_get_i2c_bus_count();
  * @param i2c_bus the logical I2C bus number
  * @return I2C adapter number in sysfs. Function will return -1 on failure
  */
-int mraa_get_i2c_bus_id(unsigned int i2c_bus);
+int mraa_get_i2c_bus_id(int i2c_bus);
 
 /**
  * Get specified platform pincount, board must be initialised.

api/mraa/common.hpp

@@ -78,7 +78,7 @@ getVersion()
  * @return The priority value set
  */
 inline int
-setPriority(const unsigned int priority)
+setPriority(const int priority)
 {
     return mraa_set_priority(priority);
 }
@@ -195,7 +195,7 @@ getI2cBusCount()
  * @return I2C adapter number in sysfs. Function will return -1 on failure
  */
 inline int
-getI2cBusId(unsigned int i2c_bus)
+getI2cBusId(int i2c_bus)
 {
     return mraa_get_i2c_bus_id(i2c_bus);
 }

include/mraa_internal_types.h

@@ -253,9 +253,9 @@ typedef struct {
  */
 typedef struct {
     /*@{*/
-    unsigned int bus_id; /**< ID as exposed in the system */
-    unsigned int scl; /**< i2c SCL */
-    unsigned int sda; /**< i2c SDA */
+    int bus_id; /**< ID as exposed in the system */
+    int scl; /**< i2c SCL */
+    int sda; /**< i2c SDA */
     // mraa_drv_api_t drv_type; /**< Driver type */
     /*@}*/
 } mraa_i2c_bus_t;
@@ -268,10 +268,10 @@ typedef struct {
     unsigned int bus_id; /**< The Bus ID as exposed to the system. */
     unsigned int slave_s; /**< Slave select */
     mraa_boolean_t three_wire; /**< Is the bus only a three wire system */
-    unsigned int sclk; /**< Serial Clock */
-    unsigned int mosi; /**< Master Out, Slave In. */
-    unsigned int miso; /**< Master In, Slave Out. */
-    unsigned int cs; /**< Chip Select, used when the board is a spi slave */
+    int sclk; /**< Serial Clock */
+    int mosi; /**< Master Out, Slave In. */
+    int miso; /**< Master In, Slave Out. */
+    int cs; /**< Chip Select, used when the board is a spi slave */
     /*@}*/
 } mraa_spi_bus_t;
 
@@ -293,19 +293,19 @@ typedef struct {
 
 typedef struct _board_t {
     /*@{*/
-    unsigned int phy_pin_count; /**< The Total IO pins on board */
+    int phy_pin_count; /**< The Total IO pins on board */
     unsigned int gpio_count; /**< GPIO Count */
     unsigned int aio_count;  /**< Analog side Count */
-    unsigned int i2c_bus_count; /**< Usable i2c Count */
+    int i2c_bus_count; /**< Usable i2c Count */
     mraa_i2c_bus_t  i2c_bus[12]; /**< Array of i2c */
     unsigned int def_i2c_bus; /**< Position in array of default i2c bus */
-    unsigned int spi_bus_count; /**< Usable spi Count */
+    int spi_bus_count; /**< Usable spi Count */
     mraa_spi_bus_t spi_bus[12];       /**< Array of spi */
     unsigned int def_spi_bus; /**< Position in array of defult spi bus */
     unsigned int adc_raw; /**< ADC raw bit value */
     unsigned int adc_supported; /**< ADC supported bit value */
     unsigned int def_uart_dev; /**< Position in array of defult uart */
-    unsigned int uart_dev_count; /**< Usable spi Count */
+    int uart_dev_count; /**< Usable spi Count */
     mraa_uart_dev_t uart_dev[6]; /**< Array of UARTs */
     mraa_boolean_t no_bus_mux; /**< i2c/spi/adc/pwm/uart bus muxing setup not required */
     int pwm_default_period; /**< The default PWM period is US */

src/iio/iio.c

@@ -284,7 +284,7 @@ mraa_iio_write_string(mraa_iio_context dev, const char* attr_name, const char* d
     snprintf(buf, MAX_SIZE, IIO_SYSFS_DEVICE "%d/%s", dev->num, attr_name);
     int fd = open(buf, O_WRONLY);
     if (fd != -1) {
-        size_t len = strlen(data);
+        int len = strlen(data);
         ssize_t status = write(fd, data, len);
         if (status == len)
              result = MRAA_SUCCESS;

src/mraa.c

@@ -217,7 +217,7 @@ mraa_deinit()
 }
 
 int
-mraa_set_priority(const unsigned int priority)
+mraa_set_priority(const int priority)
 {
     struct sched_param sched_s;
 
@@ -282,7 +282,7 @@ mraa_iio_detect()
 mraa_result_t
 mraa_setup_mux_mapped(mraa_pin_t meta)
 {
-    int mi;
+    unsigned int mi;
     mraa_result_t ret;
     mraa_gpio_context mux_i = NULL;
     int last_pin = -1;
@@ -675,7 +675,7 @@ mraa_get_i2c_bus_count()
 }
 
 int
-mraa_get_i2c_bus_id(unsigned i2c_bus)
+mraa_get_i2c_bus_id(int i2c_bus)
 {
     if (plat == NULL) {
         return -1;