Diff: Components/VL6180X/vl6180x_i2c.h

Revision:

1:1de1ea2994d9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Components/VL6180X/vl6180x_i2c.h	Wed Sep 09 16:00:39 2015 +0000
@@ -0,0 +1,166 @@
+/*
+ * $Date: 2015-01-08 14:30:24 +0100 (Thu, 08 Jan 2015) $
+ * $Revision: 2039 $
+ */
+ 
+/**
+ * @file vl6180x_i2c.h
+ *
+ * @brief  CCI interface to "raw i2c" translation layer
+ */
+
+#ifndef VL6180_I2C_H_
+#define VL6180_I2C_H_
+
+#include "vl6180x_platform.h"
+
+/**
+ * @defgroup cci_i2c  CCI to RAW I2C translation layer
+ *
+ * This optional tranlation layer is implemented in __platform/cci-i2c__ directory. If user uses this translation layer for his platform, only @a VL6180x_I2CRead() and
+ * @a VL6180x_I2CWrite() functions need to be implemented. Also, some code adaption (via macro) is required for multi-threading and for multiple device support.
+ *
+ * File vl6180x_i2c.c implements device register access via raw i2c access. If the targeted application and platform has no multi-thread,  no multi-cpu and uses single
+ * device, then nothing else is required than the 2 mandatory function : @a VL6180x_I2CRead() and @a VL6180x_I2CWrite().\n
+ * In other cases, review and customize @a VL6180x_GetI2CAccess() and @a VL6180x_DoneI2CAccess() functions as well as @a #VL6180x_I2C_USER_VAR macro. This should be enough
+ * to conform to a wide range of platform OS and application requirements .\n
+ *
+ * If your configured i2c for per device buffer via  @a #I2C_BUFFER_CONFIG == 2, you must implement @a VL6180x_GetI2cBuffer()
+ *
+ * __I2C Port sample__ \n
+ * A __linux kernel__ port need a "long flags" var for its spin_lock in all functions. the following code example declares a spin lock "lock" in the custom device structure. \n
+ * @code
+struct MyVL6180Dev_t {
+     struct VL6180xDevData_t StData;
+     ...
+     spinlock_t i2c_lock;
+};
+typedef struct MyVL6180Dev_t *VL6180xDev_t;
+
+#define VL6180x_I2C_USER_VAR   unsigned long flags;
+#define GetI2CAccess(dev)      spin_lock_irqsave(dev->i2c_lock, flags)
+#define DoneI2CAccess(dev)     spin_unlock_irqrestore(dev->i2c_lock,flags)
+@endcode
+
+*  __POSIX pthread__ application porting could be as follows :\n
+* @code
+struct MyVL6180Dev_t {
+    struct VL6180xDevData_t StData;
+    ...
+    pthread_mutex_t *lock;
+};
+typedef struct MyVL6180Dev_t *VL6180xDev_t;
+
+#define VL6180x_I2C_USER_VAR        //no need
+#define VL6180x_GetI2CAccess(dev)   pthread_mutex_lock(dev->lock)
+#define VL6180x_DoneI2CAcces(dev)   pthread_mutex_unlock(dev->lock)
+ * @endcode
+ */
+
+/**
+ * @def I2C_BUFFER_CONFIG
+ *
+ * @brief Configure device register I2C access
+ *
+ * @li 0 : one GLOBAL buffer \n
+ *   Use one global buffer of MAX_I2C_XFER_SIZE byte in data space \n
+ *   This solution is not multi-device compliant nor multi-thread cpu safe \n
+ *   It can be the best option for small 8/16 bit MCU without stack and limited ram  (STM8s, 80C51 ...)
+ *
+ * @li 1 : ON_STACK/local \n
+ *   Use local variable (on stack) buffer \n
+ *   This solution is multi-thread with use of i2c resource lock or mutex see @a VL6180x_GetI2CAccess() \n
+ *
+ * @li 2 : User defined \n
+ *    Per device potentially dynamic allocated. Requires @a VL6180x_GetI2cBuffer() to be implemented.
+ * @ingroup Configuration
+ */
+#define I2C_BUFFER_CONFIG 1
+
+/**
+ * @brief       Write data buffer to VL6180x device via i2c
+ * @param dev   The device to write to
+ * @param buff  The data buffer
+ * @param len   The length of the transaction in byte
+ * @return      0 on success
+ * @ingroup cci_i2c
+ */
+int  VL6180x_I2CWrite(VL6180xDev_t dev, uint8_t  *buff, uint8_t len);
+
+/**
+ *
+ * @brief       Read data buffer from VL6180x device via i2c
+ * @param dev   The device to read from
+ * @param buff  The data buffer to fill
+ * @param len   The length of the transaction in byte
+ * @return      0 on success
+ * @ingroup  cci_i2c
+ */
+int VL6180x_I2CRead(VL6180xDev_t dev, uint8_t *buff, uint8_t len);
+
+
+/**
+ * @brief Declare any required variables used by i2c lock (@a VL6180x_DoneI2CAccess() and @a VL6180x_GetI2CAccess())
+ * and buffer access : @a VL6180x_GetI2cBuffer()
+ *
+ * @ingroup cci_i2c
+ */
+#define VL6180x_I2C_USER_VAR
+
+/**
+ *  @brief Acquire lock or mutex for access to i2c data buffer and bus.\n
+ *  Delete the default VL6180x_GetI2CAccess 'do-nothing' macro below if you decide to implement this function.
+ *
+ *  This function is used to perform i2c bus level and multiple access locking required for multi thread/proccess system.\n
+ *  Multiple access (read and update) will lock once and do multiple basic i2c rd/wr to complete the overall transfer.\n
+ *  When no locking is needed this can be a void macro.\n
+ *
+ * @param dev  the device
+ * @ingroup cci_i2c
+ */
+void VL6180x_GetI2CAccess(VL6180xDev_t dev);
+
+/**
+ * @def VL6180x_GetI2CAccess
+ * @brief Default 'do-nothing' macro for @a VL6180x_GetI2CAccess(). Delete if used.
+ * @ingroup cci_i2c
+ */
+#define VL6180x_GetI2CAccess(dev) (void)0 /* TODO delete if function used */
+
+/**
+ * @brief Release acquired lock or mutex for i2c access.\n
+ * Delete default VL6180x_DoneI2CAccess 'do-nothing' macro below if implementing that function.
+ *
+ * This function is used to release the acquired lock.
+ * @param dev The device
+ * @ingroup cci_i2c
+ */
+void VL6180x_DoneI2CAccess(VL6180xDev_t dev);
+
+/** @def VL6180x_DoneI2CAcces
+ * @brief Default 'do-nothing' macro for @a VL6180x_DoneI2CAcces(). Delete if used.
+ * @ingroup cci_i2c
+ */
+#define VL6180x_DoneI2CAcces(dev) (void)0  /*TODO delete  if function used */
+
+/**
+ * @brief Provided data buffer for i2c access for at least n_byte.
+ *
+ * You must implement it when i2c @a #I2C_BUFFER_CONFIG is set to 2 (User defined).\n
+ * This is used used in the context of #VL6180x_I2C_USER_VAR
+ *
+ * @param dev     The device
+ * @param n_byte  Minimal number of byte
+ * @return        The buffer (cannot fail return not checked)
+ * @ingroup cci_i2c
+ */
+uint8_t *VL6180x_GetI2cBuffer(VL6180xDev_t dev, int n_byte);
+#if I2C_BUFFER_CONFIG == 2
+#error /* TODO add your macro of code here for VL6180x_GetI2cBuffer */
+#endif
+
+
+
+
+
+#endif /* VL6180_I2C_H_ */