tests/qtest: pca9555: test polarity inversion
Add tests for the polarity inversion register: the inversion is applied when reading the INPUT register, both for input pins (pull-up) and for output-driven pins, and it does not affect the OUTPUT register readback. Signed-off-by: Emmanuel Blot <emmanuel.blot@free.fr> Reviewed-by: Glenn Miles <milesg@linux.ibm.com> Link: https://lore.kernel.org/qemu-devel/20260709-catalina-upgrade-v1-12-82a63fead90c@free.fr Signed-off-by: Cédric Le Goater <clg@redhat.com>
Emmanuel Blot committed
Jul 9, 2026 at 17:23 UTC
f2fa57afffde5885d69d2db3a7a22a8c5d1eba1a
1 file changed
+44
tests/qtest/pca9555-test.c
+44
@@ -99,6 +99,46 @@ static void test_port_independence(void *obj, void *data,
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g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT1), ==, 0xAA);
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}
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+/*
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+ * Polarity inversion: reading INPUT with polarity bits set should
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+ * return the XOR of the actual input state and the polarity register.
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+ */
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+static void test_polarity_inversion(void *obj, void *data,
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+ QGuestAllocator *alloc)
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+{
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+ QI2CDevice *dev = (QI2CDevice *)obj;
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+
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xFF);
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+
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+ i2c_set8(dev, PCA9535_POLARITY0, 0xFF);
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x00);
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+
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+ i2c_set8(dev, PCA9535_POLARITY0, 0x0F);
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xF0);
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+
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0xFF);
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+
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+ i2c_set8(dev, PCA9535_POLARITY1, 0xAA);
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0x55);
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+}
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+
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+/* Polarity inversion combined with output-driven pins. */
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+static void test_polarity_with_output(void *obj, void *data,
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+ QGuestAllocator *alloc)
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+{
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+ QI2CDevice *dev = (QI2CDevice *)obj;
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+
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+ i2c_set8(dev, PCA9535_CONFIG0, 0x00);
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+ i2c_set8(dev, PCA9535_OUTPUT0, 0xA5);
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+
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xA5);
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+
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+ i2c_set8(dev, PCA9535_POLARITY0, 0xFF);
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x5A);
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+
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+ g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT0), ==, 0xA5);
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+}
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+
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static void pca9555_register_nodes(void)
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{
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QOSGraphEdgeOptions opts = {
@@ -114,6 +154,10 @@ static void pca9555_register_nodes(void)
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NULL);
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qos_add_test("input-pullup", "pca9555", test_input_pullup, NULL);
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qos_add_test("port-independence", "pca9555", test_port_independence, NULL);
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+ qos_add_test("polarity-inversion", "pca9555", test_polarity_inversion,
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+ NULL);
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+ qos_add_test("polarity-with-output", "pca9555", test_polarity_with_output,
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+ NULL);
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}
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libqos_init(pca9555_register_nodes);