[PULL 45/83] tests/qtest: pca9555: test polarity inversion

From: Emmanuel Blot <[email protected]>

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 <[email protected]>
Reviewed-by: Glenn Miles <[email protected]>
Link: https://lore.kernel.org/qemu-devel/[email protected]
Signed-off-by: Cédric Le Goater <[email protected]>
---
 tests/qtest/pca9555-test.c | 44 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/tests/qtest/pca9555-test.c b/tests/qtest/pca9555-test.c
index 6b085702c3c8..2afa061bd2e0 100644
--- a/tests/qtest/pca9555-test.c
+++ b/tests/qtest/pca9555-test.c
@@ -99,6 +99,46 @@ static void test_port_independence(void *obj, void *data,
     g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT1), ==, 0xAA);
 }
 
+/*
+ * Polarity inversion: reading INPUT with polarity bits set should
+ * return the XOR of the actual input state and the polarity register.
+ */
+static void test_polarity_inversion(void *obj, void *data,
+                                    QGuestAllocator *alloc)
+{
+    QI2CDevice *dev = (QI2CDevice *)obj;
+
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xFF);
+
+    i2c_set8(dev, PCA9535_POLARITY0, 0xFF);
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x00);
+
+    i2c_set8(dev, PCA9535_POLARITY0, 0x0F);
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xF0);
+
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0xFF);
+
+    i2c_set8(dev, PCA9535_POLARITY1, 0xAA);
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT1), ==, 0x55);
+}
+
+/* Polarity inversion combined with output-driven pins. */
+static void test_polarity_with_output(void *obj, void *data,
+                                      QGuestAllocator *alloc)
+{
+    QI2CDevice *dev = (QI2CDevice *)obj;
+
+    i2c_set8(dev, PCA9535_CONFIG0, 0x00);
+    i2c_set8(dev, PCA9535_OUTPUT0, 0xA5);
+
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0xA5);
+
+    i2c_set8(dev, PCA9535_POLARITY0, 0xFF);
+    g_assert_cmphex(i2c_get8(dev, PCA9535_INPUT0), ==, 0x5A);
+
+    g_assert_cmphex(i2c_get8(dev, PCA9535_OUTPUT0), ==, 0xA5);
+}
+
 static void pca9555_register_nodes(void)
 {
     QOSGraphEdgeOptions opts = {
@@ -114,6 +154,10 @@ static void pca9555_register_nodes(void)
                  NULL);
     qos_add_test("input-pullup", "pca9555", test_input_pullup, NULL);
     qos_add_test("port-independence", "pca9555", test_port_independence, NULL);
+    qos_add_test("polarity-inversion", "pca9555", test_polarity_inversion,
+                 NULL);
+    qos_add_test("polarity-with-output", "pca9555", test_polarity_with_output,
+                 NULL);
 }
 
 libqos_init(pca9555_register_nodes);
-- 
2.55.0