[PATCH 5/7] hw/nvram: Add a new auxiliary function to init at24c eeprom

[Hao Wu <wuhaotsh@google.com>]

In NPCM7xx boards, at24c eeproms are backed by drives. However,
these drives use unit number as unique identifier. So if we
specify two drives with the same unit number, error will occured:
`Device with id 'none85' exists`.

Instead of using i2c address as unit number, we now assign unique
unit numbers for each eeproms in each board. This avoids conflict
in providing multiple eeprom contents with the same address.

We add an auxiliary function in the at24c eeprom module for this.
This allows it to easily add at24c eeprom to non-nuvoton boards
like aspeed as well.

Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Patrick Venture<venture@google.com>
---
 hw/nvram/eeprom_at24c.c         | 18 ++++++++++++++++++
 include/hw/nvram/eeprom_at24c.h | 13 +++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 include/hw/nvram/eeprom_at24c.h

diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c
index af6f5dbb99..a9e3702b00 100644
--- a/hw/nvram/eeprom_at24c.c
+++ b/hw/nvram/eeprom_at24c.c
@@ -12,9 +12,11 @@
 #include "qapi/error.h"
 #include "qemu/module.h"
 #include "hw/i2c/i2c.h"
+#include "hw/nvram/eeprom_at24c.h"
 #include "hw/qdev-properties.h"
 #include "hw/qdev-properties-system.h"
 #include "sysemu/block-backend.h"
+#include "sysemu/blockdev.h"
 #include "qom/object.h"
 
 /* #define DEBUG_AT24C */
@@ -205,3 +207,19 @@ static void at24c_eeprom_register(void)
 }
 
 type_init(at24c_eeprom_register)
+
+void at24c_eeprom_init_one(I2CBus *i2c_bus, int bus, uint8_t addr,
+                           uint32_t rsize, int unit_number)
+{
+    I2CSlave *i2c_dev = i2c_slave_new("at24c-eeprom", addr);
+    DeviceState *dev = DEVICE(i2c_dev);
+    BlockInterfaceType type = IF_NONE;
+    DriveInfo *dinfo;
+
+    dinfo = drive_get(type, bus, unit_number);
+    if (dinfo) {
+        qdev_prop_set_drive(dev, "drive", blk_by_legacy_dinfo(dinfo));
+    }
+    qdev_prop_set_uint32(dev, "rom-size", rsize);
+    i2c_slave_realize_and_unref(i2c_dev, i2c_bus, &error_abort);
+}
diff --git a/include/hw/nvram/eeprom_at24c.h b/include/hw/nvram/eeprom_at24c.h
new file mode 100644
index 0000000000..b649557a07
--- /dev/null
+++ b/include/hw/nvram/eeprom_at24c.h
@@ -0,0 +1,13 @@
+/*
+ * *AT24C* series I2C EEPROM
+ *
+ * Copyright (c) 2015 Michael Davidsaver
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the LICENSE file in the top-level directory.
+ */
+
+/* Init one at24c eeprom device */
+void at24c_eeprom_init_one(I2CBus *i2c_bus, int bus, uint8_t addr,
+                           uint32_t rsize, int unit_number);
+
-- 
2.33.0.rc1.237.g0d66db33f3-goog