dm: Simple Watchdog uclass

This is a simple uclass for Watchdog Timers. It has four operations:
start, restart, reset, stop. Drivers must implement start, restart and
stop operations, while implementing reset is optional: It's default
implementation expires watchdog timer in one clock tick.

Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/watchdog/sandbox_wdt.c b/drivers/watchdog/sandbox_wdt.c
new file mode 100644
index 0000000000..34d90bee7e
--- /dev/null
+++ b/drivers/watchdog/sandbox_wdt.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2017 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/state.h>
+#include <wdt.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int sandbox_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+	struct sandbox_state *state = state_get_current();
+
+	state->wdt.counter = timeout;
+	state->wdt.running = true;
+
+	return 0;
+}
+
+static int sandbox_wdt_stop(struct udevice *dev)
+{
+	struct sandbox_state *state = state_get_current();
+
+	state->wdt.running = false;
+
+	return 0;
+}
+
+static int sandbox_wdt_reset(struct udevice *dev)
+{
+	struct sandbox_state *state = state_get_current();
+
+	state->wdt.reset_count++;
+
+	return 0;
+}
+
+static int sandbox_wdt_expire_now(struct udevice *dev, ulong flags)
+{
+	sandbox_wdt_start(dev, 1, flags);
+
+	return 0;
+}
+
+static int sandbox_wdt_probe(struct udevice *dev)
+{
+	struct sandbox_state *state = state_get_current();
+
+	memset(&state->wdt, 0, sizeof(state->wdt));
+
+	return 0;
+}
+
+static const struct wdt_ops sandbox_wdt_ops = {
+	.start = sandbox_wdt_start,
+	.reset = sandbox_wdt_reset,
+	.stop = sandbox_wdt_stop,
+	.expire_now = sandbox_wdt_expire_now,
+};
+
+static const struct udevice_id sandbox_wdt_ids[] = {
+	{ .compatible = "sandbox,wdt" },
+	{}
+};
+
+U_BOOT_DRIVER(wdt_sandbox) = {
+	.name = "wdt_sandbox",
+	.id = UCLASS_WDT,
+	.of_match = sandbox_wdt_ids,
+	.ops = &sandbox_wdt_ops,
+	.probe = sandbox_wdt_probe,
+};