The Aspeed 2600 I2C controller supports a slave mode which can be
tested with the I2C echo device. Test extracted from :

  https://lists.nongnu.org/archive/html/qemu-devel/2022-06/msg00183.html

Suggested-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 tests/avocado/machine_aspeed.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/avocado/machine_aspeed.py b/tests/avocado/machine_aspeed.py
index ddf05b3617..d2c57ccb7e 100644
--- a/tests/avocado/machine_aspeed.py
+++ b/tests/avocado/machine_aspeed.py
@@ -199,6 +199,8 @@ def test_arm_ast2600_evb_buildroot(self):
                          'tmp105,bus=aspeed.i2c.bus.3,address=0x4d,id=tmp-test');
         self.vm.add_args('-device',
                          'ds1338,bus=aspeed.i2c.bus.3,address=0x32');
+        self.vm.add_args('-device',
+                         'i2c-echo,bus=aspeed.i2c.bus.3,address=0x42');
         self.do_test_arm_aspeed_buildroot_start(image_path, '0xf00')
 
         exec_command_and_wait_for_pattern(self,
@@ -217,6 +219,14 @@ def test_arm_ast2600_evb_buildroot(self):
         year = time.strftime("%Y")
         exec_command_and_wait_for_pattern(self, 'hwclock -f /dev/rtc1', year);
 
+        exec_command_and_wait_for_pattern(self,
+             'echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-3/new_device',
+             'i2c i2c-3: new_device: Instantiated device slave-24c02 at 0x64');
+        exec_command(self, 'i2cset -y 3 0x42 0x64 0x00 0xaa i');
+        time.sleep(0.1)
+        exec_command_and_wait_for_pattern(self,
+             'hexdump /sys/bus/i2c/devices/3-1064/slave-eeprom',
+             '0000000 ffaa ffff ffff ffff ffff ffff ffff ffff');
         self.do_test_arm_aspeed_buildroot_poweroff()
 
 
-- 
2.39.2