Add I2C driver framework

This I2C driver framework has some major differences compared to libi2c.

* It is compatible to the Linux I2C user-space API.

* It uses generic IMFS nodes and thus reduces the levels of indirection.

* The drivers don't have to mess around with minor numbers to get their
  state information.

* No arbitrary bus controller model is assumed.  The main task of an I2C
  bus controller driver is to process I2C messages.  How this is done is
  private to the driver.

* Scatter/gather operations are supported (I2C_M_NOSTART).

testsuites/libtests/Makefile.am

@@ -1,6 +1,7 @@
 ACLOCAL_AMFLAGS = -I ../aclocal
 
 _SUBDIRS = POSIX
+_SUBDIRS += i2c01
 _SUBDIRS += newlib01
 _SUBDIRS += block17
 _SUBDIRS += exit02

testsuites/libtests/configure.ac

@@ -66,6 +66,7 @@ AS_IF([test x"$HAVE_LIBDL" = x"yes"],[
 
 # Explicitly list all Makefiles here
 AC_CONFIG_FILES([Makefile
+i2c01/Makefile
 newlib01/Makefile
 block17/Makefile
 exit02/Makefile

testsuites/libtests/i2c01/Makefile.am

@@ -0,0 +1,19 @@
+rtems_tests_PROGRAMS = i2c01
+i2c01_SOURCES = init.c
+
+dist_rtems_tests_DATA = i2c01.scn i2c01.doc
+
+include $(RTEMS_ROOT)/make/custom/@RTEMS_BSP@.cfg
+include $(top_srcdir)/../automake/compile.am
+include $(top_srcdir)/../automake/leaf.am
+
+AM_CPPFLAGS += -I$(top_srcdir)/../support/include
+
+LINK_OBJS = $(i2c01_OBJECTS)
+LINK_LIBS = $(i2c01_LDLIBS)
+
+i2c01$(EXEEXT): $(i2c01_OBJECTS) $(i2c01_DEPENDENCIES)
+	@rm -f i2c01$(EXEEXT)
+	$(make-exe)
+
+include $(top_srcdir)/../automake/local.am

testsuites/libtests/i2c01/i2c01.doc

@@ -0,0 +1,11 @@
+This file describes the directives and concepts tested by this test set.
+
+test set name: i2c01
+
+directives:
+
+  TBD
+
+concepts:
+
+  - Ensure that the I2C driver framework works.

testsuites/libtests/i2c01/i2c01.scn

@@ -0,0 +1,2 @@
+*** BEGIN OF TEST I2C 1 ***
+*** END OF TEST I2C 1 ***

testsuites/libtests/i2c01/init.c

@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#ifdef HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <dev/i2c/i2c.h>
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rtems/libcsupport.h>
+
+#include "tmacros.h"
+
+const char rtems_test_name[] = "I2C 1";
+
+#define SPARE_ADDRESS_BITS 3
+
+#define DEVICE_SIMPLE_READ_WRITE (0UL << SPARE_ADDRESS_BITS)
+
+typedef struct test_device test_device;
+
+struct test_device {
+  int (*transfer)(
+    i2c_bus *bus,
+    i2c_msg *msgs,
+    uint32_t msg_count,
+    test_device *dev
+  );
+};
+
+typedef struct {
+  test_device base;
+  char buf[3];
+} test_device_simple_read_write;
+
+typedef struct {
+  i2c_bus base;
+  unsigned long clock;
+  test_device *devices[1];
+  test_device_simple_read_write simple_read_write;
+} test_bus;
+
+static const char bus_path[] = "/dev/i2c-0";
+
+static int test_simple_read_write_transfer(
+  i2c_bus *bus,
+  i2c_msg *msgs,
+  uint32_t msg_count,
+  test_device *base
+)
+{
+  test_device_simple_read_write *dev = (test_device_simple_read_write *) base;
+
+  if (msg_count == 1 && msgs[0].len == sizeof(dev->buf)) {
+    if ((msgs[0].flags & I2C_M_RD) != 0) {
+      memcpy(msgs[0].buf, &dev->buf[0], sizeof(dev->buf));
+    } else {
+      memcpy(&dev->buf[0], msgs[0].buf, sizeof(dev->buf));
+    }
+
+    return 0;
+  } else {
+    return -EIO;
+  }
+}
+
+static int test_transfer(i2c_bus *base, i2c_msg *msgs, uint32_t msg_count)
+{
+  test_bus *bus = (test_bus *) base;
+  uint16_t addr;
+  test_device *dev;
+
+  addr = msgs[0].addr >> SPARE_ADDRESS_BITS;
+  if (addr >= RTEMS_ARRAY_SIZE(bus->devices)) {
+    return -EIO;
+  }
+
+  dev = bus->devices[addr];
+
+  return (*dev->transfer)(&bus->base, msgs, msg_count, dev);
+}
+
+static int test_set_clock(i2c_bus *base, unsigned long clock)
+{
+  test_bus *bus = (test_bus *) base;
+
+  bus->clock = clock;
+
+  return 0;
+}
+
+static void test_destroy(i2c_bus *base)
+{
+  i2c_bus_destroy_and_free(base);
+}
+
+static void test_simple_read_write(test_bus *bus, int fd)
+{
+  static const char zero[] = { 0, 0, 0 };
+  static const char abc[] = { 'a', 'b', 'c' };
+
+  int rv;
+  char buf[3];
+  ssize_t n;
+
+  rv = ioctl(fd, I2C_SLAVE, DEVICE_SIMPLE_READ_WRITE);
+  rtems_test_assert(rv == 0);
+
+  errno = 0;
+  rv = ioctl(fd, 0xb00b);
+  rtems_test_assert(rv == -1);
+  rtems_test_assert(errno == ENOTTY);
+
+  errno = 0;
+  n = write(fd, &buf[0], 1000);
+  rtems_test_assert(n == -1);
+  rtems_test_assert(errno == EIO);
+
+  errno = 0;
+  n = read(fd, &buf[0], 1000);
+  rtems_test_assert(n == -1);
+  rtems_test_assert(errno == EIO);
+
+  rtems_test_assert(
+    memcmp(&bus->simple_read_write.buf[0], &zero[0], sizeof(buf)) == 0
+  );
+
+  n = write(fd, &abc[0], sizeof(buf));
+  rtems_test_assert(n == (ssize_t) sizeof(buf));
+
+  rtems_test_assert(
+    memcmp(&bus->simple_read_write.buf[0], &abc[0], sizeof(buf)) == 0
+  );
+
+  n = read(fd, &buf[0], sizeof(buf));
+  rtems_test_assert(n == (ssize_t) sizeof(buf));
+
+  rtems_test_assert(memcmp(&buf[0], &abc[0], sizeof(buf)) == 0);
+}
+
+static void test(void)
+{
+  rtems_resource_snapshot snapshot;
+  test_bus *bus;
+  int rv;
+  int fd;
+
+  rtems_resource_snapshot_take(&snapshot);
+
+  bus = (test_bus *) i2c_bus_alloc_and_init(sizeof(*bus));
+  rtems_test_assert(bus != NULL);
+
+  bus->base.transfer = test_transfer;
+  bus->base.set_clock = test_set_clock;
+  bus->base.destroy = test_destroy;
+  bus->base.functionality = I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING
+    | I2C_FUNC_NOSTART;
+
+  bus->simple_read_write.base.transfer = test_simple_read_write_transfer;
+  bus->devices[0] = &bus->simple_read_write.base;
+
+  rv = i2c_bus_register(&bus->base, &bus_path[0]);
+  rtems_test_assert(rv == 0);
+
+  fd = open(&bus_path[0], O_RDWR);
+  rtems_test_assert(fd >= 0);
+
+  rtems_test_assert(bus->clock == 0);
+  rv = ioctl(fd, I2C_BUS_SET_CLOCK, 0xdeadbeefUL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->clock == 0xdeadbeef);
+
+  rv = ioctl(fd, I2C_BUS_OBTAIN);
+  rtems_test_assert(rv == 0);
+
+  rv = ioctl(fd, I2C_BUS_RELEASE);
+  rtems_test_assert(rv == 0);
+
+  rtems_test_assert(!bus->base.ten_bit_address);
+
+  rv = ioctl(fd, I2C_TENBIT, 1UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.ten_bit_address);
+
+  rv = ioctl(fd, I2C_TENBIT, 0UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(!bus->base.ten_bit_address);
+
+  rtems_test_assert(!bus->base.use_pec);
+
+  rv = ioctl(fd, I2C_PEC, 1UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.use_pec);
+
+  rv = ioctl(fd, I2C_PEC, 0UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(!bus->base.use_pec);
+
+  rv = ioctl(fd, I2C_SLAVE, 123UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.default_address == 123);
+
+  rv = ioctl(fd, I2C_SLAVE_FORCE, 456UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.default_address == 456);
+
+  rtems_test_assert(bus->base.retries == 0);
+
+  rv = ioctl(fd, I2C_RETRIES, 1UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.retries == 1);
+
+  rv = ioctl(fd, I2C_RETRIES, 0UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.retries == 0);
+
+  rtems_test_assert(bus->base.timeout == 0);
+
+  rv = ioctl(fd, I2C_TIMEOUT, 1UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.timeout == 5);
+
+  rv = ioctl(fd, I2C_TIMEOUT, 0UL);
+  rtems_test_assert(rv == 0);
+  rtems_test_assert(bus->base.timeout == 0);
+
+  test_simple_read_write(bus, fd);
+
+  rv = close(fd);
+  rtems_test_assert(rv == 0);
+
+  rv = unlink(&bus_path[0]);
+  rtems_test_assert(rv == 0);
+
+  rtems_test_assert(rtems_resource_snapshot_check(&snapshot));
+}
+
+static void Init(rtems_task_argument arg)
+{
+  TEST_BEGIN();
+
+  test();
+
+  TEST_END();
+  rtems_test_exit(0);
+}
+
+#define CONFIGURE_MICROSECONDS_PER_TICK 2000
+
+#define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
+#define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
+
+#define CONFIGURE_USE_IMFS_AS_BASE_FILESYSTEM
+
+#define CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS 7
+
+#define CONFIGURE_MAXIMUM_TASKS 1
+
+#define CONFIGURE_MAXIMUM_SEMAPHORES 1
+
+#define CONFIGURE_INITIAL_EXTENSIONS RTEMS_TEST_INITIAL_EXTENSION
+
+#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
+
+#define CONFIGURE_INIT
+
+#include <rtems/confdefs.h>