mraa.c: Added common function to init io from a description

Signed-off-by: Houman Brinjcargorabi <[email protected]>
Signed-off-by: Brendan Le Foll <[email protected]>

api/mraa/common.h

@@ -293,6 +293,19 @@ mraa_result_t mraa_add_subplatform(mraa_platform_t subplatformtype, const char*
  */
 mraa_result_t mraa_remove_subplatform(mraa_platform_t subplatformtype);
 
+/**
+ * Create IO using a description in the format:
+ * [io]-[pin]
+ * [io]-[raw]-[pin]
+ * [io]-[raw]-[id]-[pin]
+ * [io]-[raw]-[path]
+ *
+ * @param IO description
+ *
+ * @return void* to IO context or NULL
+ */
+void* mraa_init_io(const char* desc);
+
 #ifdef __cplusplus
 }
 #endif

api/mraa/common.hpp

@@ -309,4 +309,22 @@ removeSubplatform(Platform subplatformtype)
     return (Result) mraa_remove_subplatform((mraa_platform_t) subplatformtype);
 }
 
+/**
+ * Create IO using a description in the format:
+ * [io]-[pin]
+ * [io]-[raw]-[pin]
+ * [io]-[raw]-[id]-[pin]
+ * [io]-[raw]-[path]
+ *
+ * @param IO description
+ *
+ * @return class T initialised using pointer to IO or NULL
+ */
+template <class T>
+inline T*
+initIo(std::string desc)
+{
+    return new T(mraa_init_io(desc.c_str()));
+}
+
 }

src/mraa.c

@@ -41,6 +41,9 @@
 #include <string.h>
 #include <stdio.h>
 #include <stdbool.h>
+#include <errno.h>
+#include <ctype.h>
+#include <limits.h>
 
 #if defined(IMRAA)
 #include <json-c/json.h>
@@ -52,6 +55,12 @@
 #include "firmata/firmata_mraa.h"
 #include "gpio.h"
 #include "version.h"
+#include "i2c.h"
+#include "pwm.h"
+#include "aio.h"
+#include "spi.h"
+#include "uart.h"
+
 
 #define IIO_DEVICE_WILDCARD "iio:device*"
 mraa_board_t* plat = NULL;
@@ -1073,3 +1082,151 @@ mraa_add_from_lockfile(const char* imraa_lock_file)
     return ret;
 }
 #endif
+
+void
+mraa_to_upper(char* s)
+{
+    char* t = s;
+    for (; *t; ++t) {
+        *t = toupper(*t);
+    }
+}
+
+mraa_result_t
+mraa_atoi(char* intStr, int* value)
+{
+    char* end;
+    // here 10 determines the number base in which strol is to work
+    long val = strtol(intStr, &end, 10);
+    if (*end != '\0' || errno == ERANGE || end == intStr || val > INT_MAX || val < INT_MIN) {
+        *value = 0;
+        return MRAA_ERROR_UNSPECIFIED;
+    }
+    *value = (int) val;
+    return MRAA_SUCCESS;
+}
+
+mraa_result_t
+mraa_init_io_helper(char** str, int* value, const char* delim)
+{
+    // This function is a result of a repeated pattern within mraa_init_io
+    // when determining if a value can be derived from a string
+    char* token;
+    token = strsep(str, delim);
+    // check to see if empty string returned
+    if (token == NULL) {
+        *value = 0;
+        return MRAA_ERROR_NO_DATA_AVAILABLE;
+    }
+    return mraa_atoi(token, value);
+}
+
+void*
+mraa_init_io(const char* desc)
+{
+    const char* delim = "-";
+    int length = 0, raw = 0;
+    int pin = 0, id = 0;
+    // 256 denotes the maximum size of our buffer
+    // 8 denotes the maximum size of our type rounded to the nearest power of 2
+    // max size is 4 + 1 for the \0 = 5 rounded to 8
+    char buffer[256] = { 0 }, type[8] = { 0 };
+    char *token = 0, *str = 0;
+    length = strlen(desc);
+    // Check to see the length is less than or equal to 255 which means
+    // byte 256 is supposed to be \0
+    if (length > 255 || desc == NULL || length == 0) {
+        return NULL;
+    }
+    strncpy(buffer, desc, length);
+
+    str = buffer;
+    token = strsep(&str, delim);
+    length = strlen(token);
+    // Check to see they haven't given us a type whose length is greater than the
+    // largest type we know about
+    if (length > 4) {
+        syslog(LOG_ERR, "mraa_init_io: An invalid IO type was provided");
+        return NULL;
+    }
+    strncpy(type, token, length);
+    mraa_to_upper(type);
+    token = strsep(&str, delim);
+    // Check that they've given us more information than just the type
+    if (token == NULL) {
+        syslog(LOG_ERR, "mraa_init_io: Missing information after type");
+        return NULL;
+    }
+    // If we cannot convert the pin to a number maybe it says raw?
+    if (mraa_atoi(token, &pin) != MRAA_SUCCESS) {
+        mraa_to_upper(token);
+        if (strncmp(token, "RAW", 3)) {
+            syslog(LOG_ERR, "mraa_init_io: Description does not adhere to a known format");
+            return NULL;
+        }
+        raw = 1;
+    }
+    if (!raw && str != NULL) {
+        syslog(LOG_ERR, "mraa_init_io: More information than required was provided");
+        return NULL;
+    }
+
+    if (strncmp(type, "GPIO", 4) == 0) {
+        if (raw) {
+            if (mraa_init_io_helper(&str, &pin, delim) == MRAA_SUCCESS) {
+                return (void*) mraa_gpio_init_raw(pin);
+            }
+            syslog(LOG_ERR, "mraa_init_io: Invalid Raw description for GPIO");
+            return NULL;
+        }
+        return (void*) mraa_gpio_init(pin);
+    } else if (strncmp(type, "I2C", 3) == 0) {
+        if (raw) {
+            if (mraa_init_io_helper(&str, &pin, delim) == MRAA_SUCCESS) {
+                return (void*) mraa_i2c_init_raw(pin);
+            }
+            syslog(LOG_ERR, "mraa_init_io: Invalid Raw description for I2C");
+            return NULL;
+        }
+        return (void*) mraa_i2c_init(pin);
+    } else if (strncmp(type, "AIO", 3) == 0) {
+        if (raw) {
+            syslog(LOG_ERR, "mraa_init_io: Aio doesn't have a RAW mode");
+            return NULL;
+        }
+        return (void*) mraa_aio_init(pin);
+    } else if (strncmp(type, "PWM", 3) == 0) {
+        if (raw) {
+            if (mraa_init_io_helper(&str, &id, delim) != MRAA_SUCCESS) {
+                syslog(LOG_ERR, "mraa_init_io: Pwm, unable to convert the chip id string into a useable Int");
+                return NULL;
+            }
+            if (mraa_init_io_helper(&str, &pin, delim) != MRAA_SUCCESS) {
+                syslog(LOG_ERR, "mraa_init_io: Pwm, unable to convert the pin string into a useable Int");
+                return NULL;
+            }
+            return (void*) mraa_pwm_init_raw(id, pin);
+        }
+        return (void*) mraa_pwm_init(pin);
+    } else if (strncmp(type, "SPI", 3) == 0) {
+        if (raw) {
+            if (mraa_init_io_helper(&str, &id, delim) != MRAA_SUCCESS) {
+                syslog(LOG_ERR, "mraa_init_io: Spi, unable to convert the bus string into a useable Int");
+                return NULL;
+            }
+            if (mraa_init_io_helper(&str, &pin, delim) != MRAA_SUCCESS) {
+                syslog(LOG_ERR, "mraa_init_io: Spi, unable to convert the cs string into a useable Int");
+                return NULL;
+            }
+            return (void*) mraa_spi_init_raw(id, pin);
+        }
+        return (void*) mraa_spi_init(pin);
+    } else if (strncmp(type, "UART", 4) == 0) {
+        if (raw) {
+            return (void*) mraa_uart_init_raw(str);
+        }
+        return (void*) mraa_uart_init(pin);
+    }
+    syslog(LOG_ERR, "mraa_init_io: Invalid IO type given.");
+    return NULL;
+}