Reviewed-by: Glenn Miles <[email protected]> Thanks,
Glenn On Thu, 2026-07-09 at 17:23 +0200, Emmanuel Blot wrote: > 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); >
