dm: Add support for simple-pm-bus

This type of bus is used in Linux to designate buses which have power
domains and/or clocks which need to be enabled before their child devices
can be used. Because power domains are automatically enabled before probing
in U-Boot, we just need to enable any clocks present.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/test/dm/simple-pm-bus.c b/test/dm/simple-pm-bus.c
new file mode 100644
index 00000000000..978c7f191e7
--- /dev/null
+++ b/test/dm/simple-pm-bus.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/test.h>
+#include <dm/device-internal.h>
+#include <test/ut.h>
+#include <asm/clk.h>
+#include <asm/power-domain.h>
+
+/* These must match the ids in the device tree */
+#define TEST_CLOCK_ID 4
+#define TEST_POWER_ID 1
+
+static int dm_test_simple_pm_bus(struct unit_test_state *uts)
+{
+	struct udevice *power;
+	struct udevice *clock;
+	struct udevice *bus;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_POWER_DOMAIN,
+					      "power-domain", &power));
+	ut_assertok(uclass_get_device_by_name(UCLASS_CLK, "clk-sbox",
+					      &clock));
+	ut_asserteq(0, sandbox_power_domain_query(power, TEST_POWER_ID));
+	ut_asserteq(0, sandbox_clk_query_enable(clock, TEST_CLOCK_ID));
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_SIMPLE_BUS, "pm-bus-test",
+					      &bus));
+	ut_asserteq(1, sandbox_power_domain_query(power, TEST_POWER_ID));
+	ut_asserteq(1, sandbox_clk_query_enable(clock, TEST_CLOCK_ID));
+
+	ut_assertok(device_remove(bus, DM_REMOVE_NORMAL));
+	/* must re-probe since device_remove also removes the power domain */
+	ut_assertok(uclass_get_device_by_name(UCLASS_POWER_DOMAIN,
+					      "power-domain", &power));
+	ut_asserteq(0, sandbox_power_domain_query(power, TEST_POWER_ID));
+	ut_asserteq(0, sandbox_clk_query_enable(clock, TEST_CLOCK_ID));
+
+	return 0;
+}
+DM_TEST(dm_test_simple_pm_bus, DM_TESTF_SCAN_FDT);