1 files changed, 132 insertions, 0 deletions
diff --git a/c/src/libchip/i2c/i2c-2b-eeprom.c b/c/src/libchip/i2c/i2c-2b-eeprom.c
new file mode 100644
index 0000000000..c24463f5d5
--- /dev/null
+++ b/c/src/libchip/i2c/i2c-2b-eeprom.c
@@ -0,0 +1,132 @@
+/* $Id$ */
+
+/* Trivial i2c driver for reading "2-byte eeproms".
+ * On 'open' the read-pointer is reset to 0, subsequent
+ * read operations slurp data from there...
+ */
+
+/* Author: Till Straumann, 2005 */
+
+
+#include <rtems.h>
+#include <rtems/libi2c.h>
+
+#include <libchip/i2c-2b-eeprom.h>
+#include <rtems/libio.h>
+
+#define EEPROM_PG_SZ	32
+#define ALGN(x)	(((unsigned32)(x) + EEPROM_PG_SZ) & ~(EEPROM_PG_SZ-1))
+
+static rtems_status_code
+send_file_ptr (rtems_device_minor_number minor, unsigned pos, int tout)
+{
+  int sc;
+  unsigned char bytes[2];
+
+  bytes[0] = (pos >> 8) & 0xff;
+  bytes[1] = (pos) & 0xff;
+
+  /* poll addressing the next page; if 'tout' is <=0 we only try once
+   * and return the status. If 'tout' is positive, we try 'tout' times
+   * and return RTEMS_TIMEOUT if it didnt work
+   */
+  while ((sc = rtems_libi2c_start_write_bytes (minor, bytes, 2)) < 0) {
+    if (--tout <= 0)
+      return tout ? -sc : RTEMS_TIMEOUT;
+    rtems_task_wake_after (1);
+  }
+  return RTEMS_SUCCESSFUL;
+}
+
+static rtems_status_code
+i2c_2b_eeprom_write (rtems_device_major_number major,
+                     rtems_device_minor_number minor, void *arg)
+{
+  rtems_libio_rw_args_t *rwargs = arg;
+  unsigned off = rwargs->offset;
+  int cnt = rwargs->count;
+  char *buf = rwargs->buffer;
+  int sc;
+  unsigned end;
+  int l;
+
+  if (cnt <= 0)
+    return RTEMS_SUCCESSFUL;
+
+  if ((sc = send_file_ptr (minor, off, 0)))
+    return sc;
+
+  do {
+    /* write up to next page boundary */
+    end = ALGN (off);
+    l = end - off;
+    if (l > cnt)
+      l = cnt;
+
+    sc = rtems_libi2c_write_bytes (minor, buf, l);
+    if (sc < 0)
+      return -sc;
+
+    sc = rtems_libi2c_send_stop (minor);
+    if (sc)
+      return sc;
+
+    rwargs->bytes_moved += l;
+
+    buf += l;
+    cnt -= l;
+    off += l;
+
+    /* poll addressing the next page */
+    if ((sc = send_file_ptr (minor, off, 100)))
+      return sc;
+
+  } while (cnt > 0);
+
+  return rtems_libi2c_send_stop (minor);
+}
+
+static rtems_status_code
+i2c_2b_eeprom_read (rtems_device_major_number major,
+                    rtems_device_minor_number minor, void *arg)
+{
+  int sc;
+  rtems_libio_rw_args_t *rwargs = arg;
+
+  if (RTEMS_SUCCESSFUL != (sc = send_file_ptr (minor, rwargs->offset, 0)))
+    return -sc;
+
+  sc = rtems_libi2c_start_read_bytes (minor, rwargs->buffer, rwargs->count);
+
+  if (sc < 0) {
+    rwargs->bytes_moved = 0;
+    return -sc;
+  }
+  rwargs->bytes_moved = sc;
+
+  return rtems_libi2c_send_stop (minor);
+}
+
+static rtems_driver_address_table myops = {
+  read_entry:  i2c_2b_eeprom_read,
+  write_entry: i2c_2b_eeprom_write,
+};
+
+static rtems_libi2c_drv_t my_drv_tbl = {
+  ops:         &myops,
+  size:        sizeof (my_drv_tbl),
+};
+
+/* provide a second table for R/O access */
+static rtems_driver_address_table my_ro_ops = {
+  read_entry:  i2c_2b_eeprom_read,
+};
+
+static rtems_libi2c_drv_t my_ro_drv_tbl = {
+  ops:         &my_ro_ops,
+  size:        sizeof (my_ro_drv_tbl),
+};
+
+
+rtems_libi2c_drv_t *i2c_2b_eeprom_driver_descriptor = &my_drv_tbl;
+rtems_libi2c_drv_t *i2c_2b_eeprom_ro_driver_descriptor = &my_ro_drv_tbl;