diff --git a/docs/src/main.dox b/docs/src/main.dox
index bfe6f036c..c92192fff 100644
--- a/docs/src/main.dox
+++ b/docs/src/main.dox
@@ -358,10 +358,14 @@
* @defgroup IOPorts Abstract I/O Ports
* @brief Abstract digital I/O ports.
* @details This module defines an abstract interface for digital I/O ports.
- * Note that no code is present, I/O ports are just a set of macros that must
- * be implemented by an @ref IOPortsLLD.
- * This system has the advantage to make the access to I/O ports platform
- * independent from the implementation logic.
+ * Note that I/O ports functions are just a set of macros. The macros
+ * have default software implementation that can be redefined by an
+ * @ref IOPortsLLD if the target hardware supports special features like, as
+ * example, atomic bit set/reset/masking. Please refer to the documentation
+ * of the low level drivers for each port.
+ * This abstraction system has the advantage to make the access to the I/O
+ * ports platform independent and still be optimized for the specific
+ * architecture.
* Currently the I/O ports interface does not handle physical port programming
* like direction, pull up/down resistors etc. The interface only allows input
* and output operations but this may change in future releases.
diff --git a/ports/ARM7-LPC214x/ioports_lld.h b/ports/ARM7-LPC214x/ioports_lld.h
index db82b8f97..cedc9e361 100644
--- a/ports/ARM7-LPC214x/ioports_lld.h
+++ b/ports/ARM7-LPC214x/ioports_lld.h
@@ -20,7 +20,7 @@
/**
* @file ports/ARM-LPC214x/ioports_lld.h
* @brief LPC214x FIO low level driver
- * @addtogroup LPC214X_IOPORTS
+ * @addtogroup LPC214x_IOPORTS
* @{
*/
diff --git a/ports/ARM7-LPC214x/port.dox b/ports/ARM7-LPC214x/port.dox
index 35f0d128f..7db0867b2 100644
--- a/ports/ARM7-LPC214x/port.dox
+++ b/ports/ARM7-LPC214x/port.dox
@@ -57,6 +57,7 @@
* - Direct read of input pads regardless of the pad setting.
* .
* The only non atomic operations are bit toggling and bus writing.
+ *
* @ingroup LPC214x
*/
diff --git a/src/include/ioports.h b/src/include/ioports.h
index 94488640a..5fd330d51 100644
--- a/src/include/ioports.h
+++ b/src/include/ioports.h
@@ -71,16 +71,30 @@ typedef struct {
*
* @param[in] port the port identifier
* @param[in] bits the bits to be written on the specified port
+ *
+ * @note The default implementation does nothing except computing the
+ * parameters eventual side effects.
*/
+#if !defined(ioport_write_lld) || defined(__DOXYGEN__)
+#define chPortWrite(port, bits) ((void)(port), (void)(bits))
+#else
#define chPortWrite(port, bits) ioport_write_lld(port, bits)
+#endif
/**
* @brief Reads an I/O port.
*
* @param[in] port the port identifier
* @return the port bits
+ *
+ * @note The default implementation always return zero and computes the
+ * parameter eventual side effects.
*/
+#if !defined(ioport_read_lld) || defined(__DOXYGEN__)
+#define chPortRead(port) ((void)(port), 0)
+#else
#define chPortRead(port) ioport_read_lld(port)
+#endif
/**
* @brief Sets a bits mask on a I/O port.
@@ -91,8 +105,18 @@ typedef struct {
* @note The operation is not guaranteed to be atomic on all the architectures,
* for atomicity and/or portability reasons you may need to enclose port
* I/O operations between @p chSysLock() and @p chSysUnlock().
+ * @note The default implementation is non atomical and not necessarily
+ * optimal. Low level drivers may optimize the function by using
+ * specific hardware or coding.
*/
+#if !defined(ioport_set_lld) || defined(__DOXYGEN__)
+#define chPortSet(port, bits) { \
+ ioport_t p = (port); \
+ chPortWrite(p, chPortRead(p) | (bits)); \
+}
+#else
#define chPortSet(port, bits) ioport_set_lld(port, bits)
+#endif
/**
* @brief Clears a bits mask on a I/O port.
@@ -103,8 +127,18 @@ typedef struct {
* @note The operation is not guaranteed to be atomic on all the architectures,
* for atomicity and/or portability reasons you may need to enclose port
* I/O operations between @p chSysLock() and @p chSysUnlock().
+ * @note The default implementation is non atomical and not necessarily
+ * optimal. Low level drivers may optimize the function by using
+ * specific hardware or coding.
*/
+#if !defined(ioport_clear_lld) || defined(__DOXYGEN__)
+#define chPortClear(port, bits) { \
+ ioport_t p = (port); \
+ chPortWrite(p, chPortRead(p) & ~(bits)); \
+}
+#else
#define chPortClear(port, bits) ioport_clear_lld(port, bits)
+#endif
/**
* @brief Toggles a bits mask on a I/O port.
@@ -115,8 +149,18 @@ typedef struct {
* @note The operation is not guaranteed to be atomic on all the architectures,
* for atomicity and/or portability reasons you may need to enclose port
* I/O operations between @p chSysLock() and @p chSysUnlock().
+ * @note The default implementation is non atomical and not necessarily
+ * optimal. Low level drivers may optimize the function by using
+ * specific hardware or coding.
*/
+#if !defined(ioport_toggle_lld) || defined(__DOXYGEN__)
+#define chPortToggle(port, bits) { \
+ ioport_t p = (port); \
+ chPortWrite(p, chPortRead(p) ^ (bits)); \
+}
+#else
#define chPortToggle(port, bits) ioport_toggle_lld(port, bits)
+#endif
/**
* @brief Writes a value on an I/O bus.
@@ -128,8 +172,19 @@ typedef struct {
* @note The operation is not guaranteed to be atomic on all the architectures,
* for atomicity and/or portability reasons you may need to enclose port
* I/O operations between @p chSysLock() and @p chSysUnlock().
+ * @note The default implementation is non atomical and not necessarily
+ * optimal. Low level drivers may optimize the function by using
+ * specific hardware or coding.
*/
+#if !defined(ioport_writebus_lld) || defined(__DOXYGEN__)
+#define chPortWriteBus(bus, bits) { \
+ IOBus *b = (bus); \
+ chPortWrite(b->bus_port, (chPortRead(b->bus_port) & ~b->bus_mask) | \
+ (((bits) << b->bus_offset) & b->bus_mask)); \
+}
+#else
#define chPortWriteBus(bus, bits) ioport_writebus_lld(bus, bits)
+#endif
/**
* @brief Reads a value from an I/O bus.
@@ -140,8 +195,17 @@ typedef struct {
* @note The operation is not guaranteed to be atomic on all the architectures,
* for atomicity and/or portability reasons you may need to enclose port
* I/O operations between @p chSysLock() and @p chSysUnlock().
+ * @note The default implementation not necessarily optimal. Low level drivers
+ * may optimize the function by using specific hardware or coding.
+ * @note The default implementation evaluates the parameter three times, be
+ * careful with side effects.
*/
+#if !defined(ioport_readbus_lld) || defined(__DOXYGEN__)
+#define chPortReadBus(bus) \
+ ((chPortRead((bus)->bus_port) >> (bus)->bus_offset) & (bus)->bus_mask)
+#else
#define chPortReadBus(bus) ioport_readbus_lld(bus)
+#endif
#endif /* _IOPORTS_H_ */