Exercise the PCA9545 4-channel I2C mux: channel selection through the control byte, upper-nibble read-back, and interrupt logic.
Signed-off-by: Emmanuel Blot <[email protected]> --- tests/qtest/meson.build | 1 + tests/qtest/pca9545-test.c | 116 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build index c3593f7530..2da91ee791 100644 --- a/tests/qtest/meson.build +++ b/tests/qtest/meson.build @@ -330,6 +330,7 @@ qos_test_ss.add( 'ne2000-test.c', 'tulip-test.c', 'nvme-test.c', + 'pca9545-test.c', 'pca9552-test.c', 'pca9554-test.c', 'pca9555-test.c', diff --git a/tests/qtest/pca9545-test.c b/tests/qtest/pca9545-test.c new file mode 100644 index 0000000000..91f56db92f --- /dev/null +++ b/tests/qtest/pca9545-test.c @@ -0,0 +1,116 @@ +/* + * QTest testcase for the PCA9545 4-channel I2C switch with interrupt logic + * + * Copyright (c) 2026 Meta Platforms, Inc. and affiliates. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "libqtest-single.h" +#include "libqos/qgraph.h" +#include "libqos/i2c.h" + +#define PCA9545_TEST_ID "pca9545-test" +#define PCA9545_TEST_ADDR 0x70 +#define PCA9545_TEST_PATH "/machine/peripheral/" PCA9545_TEST_ID + +/* INTn and INT are active low: level 0 is asserted. */ +#define INT_ASSERTED 0 +#define INT_RELEASED 1 + +/* The mux has no register pointer: a read/write moves a single control byte. */ +static uint8_t pca9545_get(QI2CDevice *dev) +{ + uint8_t val; + + qi2c_recv(dev, &val, 1); + return val; +} + +static void pca9545_set(QI2CDevice *dev, uint8_t val) +{ + qi2c_send(dev, &val, 1); +} + +static void pca9545_set_int(unsigned chan, int level) +{ + qtest_set_irq_in(global_qtest, PCA9545_TEST_PATH, "interrupt", chan, level); +} + +/* Channel selection is the lower nibble; the upper nibble reads back 0. */ +static void test_channel_select(void *obj, void *data, QGuestAllocator *alloc) +{ + QI2CDevice *dev = (QI2CDevice *)obj; + + g_assert_cmphex(pca9545_get(dev), ==, 0x00); + + pca9545_set(dev, 0x05); /* channels 0 and 2 */ + g_assert_cmphex(pca9545_get(dev), ==, 0x05); + + pca9545_set(dev, 0x0f); /* all channels */ + g_assert_cmphex(pca9545_get(dev), ==, 0x0f); + + pca9545_set(dev, 0x00); + g_assert_cmphex(pca9545_get(dev), ==, 0x00); +} + +/* + * The interrupt status is reported in the upper nibble (INT3..INT0) and is + * latched regardless of which channels are selected (PCA9545A Table 5). + */ +static void test_interrupt_status(void *obj, void *data, QGuestAllocator *alloc) +{ + QI2CDevice *dev = (QI2CDevice *)obj; + + pca9545_set_int(1, INT_ASSERTED); + g_assert_cmphex(pca9545_get(dev), ==, 0x20); + + pca9545_set(dev, 0x01); + pca9545_set_int(3, INT_ASSERTED); + g_assert_cmphex(pca9545_get(dev), ==, 0xa1); /* INT3 | INT1 | channel 0 */ + + pca9545_set_int(1, INT_RELEASED); + g_assert_cmphex(pca9545_get(dev), ==, 0x81); /* INT3 | channel 0 */ +} + +/* The INT output is pulled low while any channel interrupt is active. */ +static void test_interrupt_output(void *obj, void *data, QGuestAllocator *alloc) +{ + qtest_irq_intercept_out_named(global_qtest, PCA9545_TEST_PATH, + "interrupt-out"); + + /* + * Interception starts with no recorded level, so drive an idle input + * first to make the mux publish the released state of its output. + */ + pca9545_set_int(0, INT_RELEASED); + g_assert_true(get_irq(0)); + + pca9545_set_int(0, INT_ASSERTED); + g_assert_false(get_irq(0)); + + pca9545_set_int(2, INT_ASSERTED); + g_assert_false(get_irq(0)); + + pca9545_set_int(0, INT_RELEASED); + g_assert_false(get_irq(0)); + pca9545_set_int(2, INT_RELEASED); + g_assert_true(get_irq(0)); +} + +static void pca9545_register_nodes(void) +{ + QOSGraphEdgeOptions opts = { + .extra_device_opts = "id=" PCA9545_TEST_ID ",address=0x70" + }; + add_qi2c_address(&opts, &(QI2CAddress) { PCA9545_TEST_ADDR }); + + qos_node_create_driver("pca9545", i2c_device_create); + qos_node_consumes("pca9545", "i2c-bus", &opts); + + qos_add_test("channel-select", "pca9545", test_channel_select, NULL); + qos_add_test("interrupt-status", "pca9545", test_interrupt_status, NULL); + qos_add_test("interrupt-output", "pca9545", test_interrupt_output, NULL); +} +libqos_init(pca9545_register_nodes); -- 2.50.1
