Add tests covering the pin I/O semantics of the expander: output-driven pins reflected in the input register, the pull-up seen on input-configured pins, and the independence of the two 8-bit ports.
Signed-off-by: Emmanuel Blot <[email protected]> --- tests/qtest/pca9555-test.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) diff --git a/tests/qtest/pca9555-test.c b/tests/qtest/pca9555-test.c index 5945c3441e..6b085702c3 100644 --- a/tests/qtest/pca9555-test.c +++ b/tests/qtest/pca9555-test.c @@ -28,6 +28,77 @@ static void test_reset_defaults(void *obj, void *data, QGuestAllocator *alloc) g_assert_cmphex(i2c_get8(dev, PCA9535_CONFIG1), ==, 0xFF); } +/* + * When a pin is configured as output and driven low (output=0, config=0), + * the input register should reflect 0 for that pin. + * When driven high (output=1, config=0), input should reflect 1. + * When configured as input (config=1), PCA5555 pull-up makes it read 1. + */ +static void test_output_drives_input(void *obj, void *data, + QGuestAllocator *alloc) +{ + QI2CDevice *dev = (QI2CDevice *)obj; + + i2c_set8(dev, PCA9535_CONFIG0, 0xF0); + i2c_set8(dev, PCA9535_OUTPUT0, 0xFA); + + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xFA); + + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0xFF); + + i2c_set8(dev, PCA9535_CONFIG0, 0x00); + i2c_set8(dev, PCA9535_OUTPUT0, 0x00); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x00); + + i2c_set8(dev, PCA9535_OUTPUT0, 0xFF); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xFF); +} + +/* + * When all pins are inputs (config=0xFF) and no external driver, + * PCA9555 pull-ups should make the input register read all ones. + * Switching a pin to output mode with output=0 should drive it low. + */ +static void test_input_pullup(void *obj, void *data, QGuestAllocator *alloc) +{ + QI2CDevice *dev = (QI2CDevice *)obj; + + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xFF); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0xFF); + + i2c_set8(dev, PCA9535_OUTPUT0, 0x00); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xFF); + + i2c_set8(dev, PCA9535_CONFIG0, 0x00); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x00); +} + +/* + * Test that both ports are independent: changing port 0 registers + * should not affect port 1 and vice versa. + */ +static void test_port_independence(void *obj, void *data, + QGuestAllocator *alloc) +{ + QI2CDevice *dev = (QI2CDevice *)obj; + + i2c_set8(dev, PCA9535_CONFIG0, 0x00); + i2c_set8(dev, PCA9535_OUTPUT0, 0x00); + + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x00); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0xFF); + g_assert_cmphex(i2c_get8(dev, PCA9535_CONFIG1), ==, 0xFF); + g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT1), ==, 0xFF); + + i2c_set8(dev, PCA9535_CONFIG1, 0x00); + i2c_set8(dev, PCA9535_OUTPUT1, 0xAA); + + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x00); + g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0xAA); + g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT0), ==, 0x00); + g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT1), ==, 0xAA); +} + static void pca9555_register_nodes(void) { QOSGraphEdgeOptions opts = { @@ -39,6 +110,10 @@ static void pca9555_register_nodes(void) qos_node_consumes("pca9555", "i2c-bus", &opts); qos_add_test("reset-defaults", "pca9555", test_reset_defaults, NULL); + qos_add_test("output-drives-input", "pca9555", test_output_drives_input, + NULL); + qos_add_test("input-pullup", "pca9555", test_input_pullup, NULL); + qos_add_test("port-independence", "pca9555", test_port_independence, NULL); } libqos_init(pca9555_register_nodes); -- 2.50.1
