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>
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index dbdaafc..e8d2dba 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1,8 +1,26 @@
-menu "WATCHDOG support"
+menu "Watchdog Timer Support"
config ULP_WATCHDOG
bool "i.MX7ULP watchdog"
help
Say Y here to enable i.MX7ULP watchdog driver.
+config WDT
+ bool "Enable driver model for watchdog timer drivers"
+ depends on DM
+ help
+ Enable driver model for watchdog timer. At the moment the API
+ is very simple and only supports four operations:
+ start, restart, stop and reset (expire immediately).
+ What exactly happens when the timer expires is up to a particular
+ device/driver.
+
+config WDT_SANDBOX
+ bool "Enable Watchdog Timer support for Sandbox"
+ depends on SANDBOX && WDT
+ help
+ Enable Watchdog Timer support in Sandbox. This is a dummy device that
+ can be probed and supports all of the methods of WDT, but does not
+ really do anything.
+
endmenu
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 36745ca..e891d64 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -15,3 +15,5 @@
obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
obj-$(CONFIG_DESIGNWARE_WATCHDOG) += designware_wdt.o
obj-$(CONFIG_ULP_WATCHDOG) += ulp_wdog.o
+obj-$(CONFIG_WDT) += wdt-uclass.o
+obj-$(CONFIG_WDT_SANDBOX) += sandbox_wdt.o
diff --git a/drivers/watchdog/sandbox_wdt.c b/drivers/watchdog/sandbox_wdt.c
new file mode 100644
index 0000000..34d90be
--- /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,
+};
diff --git a/drivers/watchdog/wdt-uclass.c b/drivers/watchdog/wdt-uclass.c
new file mode 100644
index 0000000..ab8a64c
--- /dev/null
+++ b/drivers/watchdog/wdt-uclass.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright 2017 Google, Inc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <wdt.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int wdt_start(struct udevice *dev, u64 timeout, ulong flags)
+{
+ const struct wdt_ops *ops = device_get_ops(dev);
+
+ if (!ops->start)
+ return -ENOSYS;
+
+ return ops->start(dev, timeout, flags);
+}
+
+int wdt_stop(struct udevice *dev)
+{
+ const struct wdt_ops *ops = device_get_ops(dev);
+
+ if (!ops->stop)
+ return -ENOSYS;
+
+ return ops->stop(dev);
+}
+
+int wdt_reset(struct udevice *dev)
+{
+ const struct wdt_ops *ops = device_get_ops(dev);
+
+ if (!ops->reset)
+ return -ENOSYS;
+
+ return ops->reset(dev);
+}
+
+int wdt_expire_now(struct udevice *dev, ulong flags)
+{
+ int ret = 0;
+ const struct wdt_ops *ops;
+
+ debug("WDT Resettting: %lu\n", flags);
+ ops = device_get_ops(dev);
+ if (ops->expire_now) {
+ return ops->expire_now(dev, flags);
+ } else {
+ if (!ops->start)
+ return -ENOSYS;
+
+ ret = ops->start(dev, 1, flags);
+ if (ret < 0)
+ return ret;
+
+ hang();
+ }
+
+ return ret;
+}
+
+UCLASS_DRIVER(wdt) = {
+ .id = UCLASS_WDT,
+ .name = "wdt",
+};