dm: irq: Add support for requesting interrupts

At present driver model supports the IRQ uclass but there is no way to
request a particular interrupt for a driver.

Add a mechanism, similar to clock and reset, to read the interrupts
required by a device from the device tree and to request those interrupts.

U-Boot itself does not have interrupt-driven handlers, so just provide a
means to read and clear an interrupt. This can be useful to handle
peripherals which must use an interrupt to determine when data is
available, for example.

Bring over the basic binding file as well, from Linux v5.4. Note that the
older binding is not supported in U-Boot; the newer 'special form' must be
used.

Add a simple test of the new functionality.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/test/dm/irq.c b/test/dm/irq.c
index adbcffbe9c..192d80d7e1 100644
--- a/test/dm/irq.c
+++ b/test/dm/irq.c
@@ -43,3 +43,35 @@ static int dm_test_irq_type(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_irq_type, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test of irq_read_and_clear() */
+static int dm_test_read_and_clear(struct unit_test_state *uts)
+{
+	struct irq irq;
+
+	ut_assertok(irq_first_device_type(SANDBOX_IRQT_BASE, &irq.dev));
+	irq.id = SANDBOX_IRQN_PEND;
+	ut_asserteq(0, irq_read_and_clear(&irq));
+	ut_asserteq(0, irq_read_and_clear(&irq));
+	ut_asserteq(0, irq_read_and_clear(&irq));
+	ut_asserteq(1, irq_read_and_clear(&irq));
+	ut_asserteq(0, irq_read_and_clear(&irq));
+
+	return 0;
+}
+DM_TEST(dm_test_read_and_clear, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test of irq_request() */
+static int dm_test_request(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	struct irq irq;
+
+	ut_assertok(uclass_first_device_err(UCLASS_TEST_FDT, &dev));
+	ut_asserteq_str("a-test", dev->name);
+	ut_assertok(irq_get_by_index(dev, 0, &irq));
+	ut_asserteq(3, irq.id);
+
+	return 0;
+}
+DM_TEST(dm_test_request, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);