event: Add events for device probe/remove

Generate events when devices are probed or removed, allowing hooks
to be added for these situations.

This is controlled by the DM_EVENT config option.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/event.c

@@ -24,6 +24,12 @@ DECLARE_GLOBAL_DATA_PTR;
 const char *const type_name[] = {
 	"none",
 	"test",
+
+	/* Events related to driver model */
+	"dm_pre_probe",
+	"dm_post_probe",
+	"dm_pre_remove",
+	"dm_post_remove",
 };
 
 _Static_assert(ARRAY_SIZE(type_name) == EVT_COUNT, "event type_name size");

drivers/core/Kconfig

@@ -77,6 +77,16 @@ config DM_DEVICE_REMOVE
 	  it causes unplugged devices to linger around in the dm-tree, and it
 	  causes USB host controllers to not be stopped when booting the OS.
 
+config DM_EVENT
+	bool "Support events with driver model"
+	depends on DM
+	imply EVENT
+	default y if SANDBOX
+	help
+	  This enables support for generating events related to driver model
+	  operations, such as prbing or removing a device. Subsystems can
+	  register a 'spy' function that is called when the event occurs.
+
 config SPL_DM_DEVICE_REMOVE
 	bool "Support device removal in SPL"
 	depends on SPL_DM

drivers/core/device-remove.c

@@ -207,6 +207,10 @@ int device_remove(struct udevice *dev, uint flags)
 	if (!(dev_get_flags(dev) & DM_FLAG_ACTIVATED))
 		return 0;
 
+	ret = device_notify(dev, EVT_DM_PRE_REMOVE);
+	if (ret)
+		return ret;
+
 	/*
 	 * If the child returns EKEYREJECTED, continue. It just means that it
 	 * didn't match the flags.
@@ -256,6 +260,10 @@ int device_remove(struct udevice *dev, uint flags)
 
 	dev_bic_flags(dev, DM_FLAG_ACTIVATED);
 
+	ret = device_notify(dev, EVT_DM_POST_REMOVE);
+	if (ret)
+		goto err_remove;
+
 	return 0;
 
 err_remove:

drivers/core/device.c

@@ -10,6 +10,7 @@
 
 #include <common.h>
 #include <cpu_func.h>
+#include <event.h>
 #include <log.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
@@ -493,6 +494,10 @@ int device_probe(struct udevice *dev)
 	if (dev_get_flags(dev) & DM_FLAG_ACTIVATED)
 		return 0;
 
+	ret = device_notify(dev, EVT_DM_PRE_PROBE);
+	if (ret)
+		return ret;
+
 	drv = dev->driver;
 	assert(drv);
 
@@ -597,6 +602,10 @@ int device_probe(struct udevice *dev)
 				  dev->name, ret, errno_str(ret));
 	}
 
+	ret = device_notify(dev, EVT_DM_POST_PROBE);
+	if (ret)
+		return ret;
+
 	return 0;
 fail_uclass:
 	if (device_remove(dev, DM_REMOVE_NORMAL)) {

include/dm/device-internal.h

@@ -10,6 +10,7 @@
 #ifndef _DM_DEVICE_INTERNAL_H
 #define _DM_DEVICE_INTERNAL_H
 
+#include <event.h>
 #include <linker_lists.h>
 #include <dm/ofnode.h>
 
@@ -426,4 +427,13 @@ static inline void devres_release_all(struct udevice *dev)
 }
 
 #endif /* ! CONFIG_DEVRES */
+
+static inline int device_notify(const struct udevice *dev, enum event_t type)
+{
+#if CONFIG_IS_ENABLED(DM_EVENT)
+	return event_notify(type, &dev, sizeof(dev));
+#else
+	return 0;
+#endif
+}
 #endif

include/event.h

@@ -19,6 +19,12 @@ enum event_t {
 	EVT_NONE,
 	EVT_TEST,
 
+	/* Events related to driver model */
+	EVT_DM_PRE_PROBE,
+	EVT_DM_POST_PROBE,
+	EVT_DM_PRE_REMOVE,
+	EVT_DM_POST_REMOVE,
+
 	EVT_COUNT
 };
 
@@ -31,6 +37,15 @@ union event_data {
 	struct event_data_test {
 		int signal;
 	} test;
+
+	/**
+	 * struct event_dm - driver model event
+	 *
+	 * @dev: Device this event relates to
+	 */
+	struct event_dm {
+		struct udevice *dev;
+	} dm;
 };
 
 /**

test/common/event.c

@@ -45,3 +45,41 @@ static int test_event_base(struct unit_test_state *uts)
 	return 0;
 }
 COMMON_TEST(test_event_base, 0);
+
+static int h_probe(void *ctx, struct event *event)
+{
+	struct test_state *test_state = ctx;
+
+	test_state->dev = event->data.dm.dev;
+	switch (event->type) {
+	case EVT_DM_PRE_PROBE:
+		test_state->val |= 1;
+		break;
+	case EVT_DM_POST_PROBE:
+		test_state->val |= 2;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int test_event_probe(struct unit_test_state *uts)
+{
+	struct test_state state;
+	struct udevice *dev;
+
+	state.val = 0;
+	ut_assertok(event_register("pre", EVT_DM_PRE_PROBE, h_probe, &state));
+	ut_assertok(event_register("post", EVT_DM_POST_PROBE, h_probe, &state));
+
+	/* Probe a device */
+	ut_assertok(uclass_first_device_err(UCLASS_TEST_FDT, &dev));
+
+	/* Check that the handler is called */
+	ut_asserteq(3, state.val);
+
+	return 0;
+}
+COMMON_TEST(test_event_probe, UT_TESTF_DM | UT_TESTF_SCAN_FDT);