Add SIGALRM based watchdog driver. This can reset barebox if stuck and
plays nicely with $global.system.reset.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
v1 -> v2: no changes
---
arch/sandbox/board/Makefile | 1 +
arch/sandbox/board/watchdog.c | 84 +++++++++++++++++++
arch/sandbox/dts/sandbox.dts | 5 ++
.../sandbox/mach-sandbox/include/mach/linux.h | 2 +
arch/sandbox/os/common.c | 25 ++++++
5 files changed, 117 insertions(+)
create mode 100644 arch/sandbox/board/watchdog.c
diff --git a/arch/sandbox/board/Makefile b/arch/sandbox/board/Makefile
index e50d2ca0f148..c504c967decd 100644
--- a/arch/sandbox/board/Makefile
+++ b/arch/sandbox/board/Makefile
@@ -6,5 +6,6 @@ obj-y += devices.o
obj-y += dtb.o
obj-y += power.o
obj-y += dev-random.o
+obj-y += watchdog.o
extra-y += barebox.lds
diff --git a/arch/sandbox/board/watchdog.c b/arch/sandbox/board/watchdog.c
new file mode 100644
index 000000000000..336451282fd3
--- /dev/null
+++ b/arch/sandbox/board/watchdog.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <common.h>
+#include <errno.h>
+#include <driver.h>
+#include <mach/linux.h>
+#include <of.h>
+#include <watchdog.h>
+#include <mfd/syscon.h>
+#include <reset_source.h>
+
+struct sandbox_watchdog {
+ struct watchdog wdd;
+ bool cant_disable :1;
+};
+
+static inline struct sandbox_watchdog *to_sandbox_watchdog(struct watchdog *wdd)
+{
+ return container_of(wdd, struct sandbox_watchdog, wdd);
+}
+
+static int sandbox_watchdog_set_timeout(struct watchdog *wdd, unsigned int timeout)
+{
+ struct sandbox_watchdog *wd = to_sandbox_watchdog(wdd);
+
+ if (!timeout && wd->cant_disable)
+ return -ENOSYS;
+
+ if (timeout > wdd->timeout_max)
+ return -EINVAL;
+
+ return linux_watchdog_set_timeout(timeout);
+}
+
+static int sandbox_watchdog_probe(struct device_d *dev)
+{
+ struct device_node *np = dev->device_node;
+ struct sandbox_watchdog *wd;
+ struct watchdog *wdd;
+ struct regmap *src;
+ u32 src_offset;
+ int ret;
+
+ wd = xzalloc(sizeof(*wd));
+
+ wdd = &wd->wdd;
+ wdd->hwdev = dev;
+ wdd->set_timeout = sandbox_watchdog_set_timeout;
+ wdd->timeout_max = 1000;
+
+ wd->cant_disable = of_property_read_bool(np, "barebox,cant-disable");
+
+ ret = watchdog_register(wdd);
+ if (ret) {
+ dev_err(dev, "Failed to register watchdog device\n");
+ return ret;
+ }
+
+ src = syscon_regmap_lookup_by_phandle(np, "barebox,reset-source");
+ if (IS_ERR(src))
+ return 0;
+
+ ret = of_property_read_u32_index(np, "barebox,reset-source", 1, &src_offset);
+ if (ret)
+ return 0;
+
+ regmap_update_bits(src, src_offset, 0xff, RESET_WDG);
+
+ dev_info(dev, "probed\n");
+ return 0;
+}
+
+
+static __maybe_unused struct of_device_id sandbox_watchdog_dt_ids[] = {
+ { .compatible = "barebox,sandbox-watchdog" },
+ { /* sentinel */ }
+};
+
+static struct driver_d sandbox_watchdog_drv = {
+ .name = "sandbox-watchdog",
+ .of_compatible = sandbox_watchdog_dt_ids,
+ .probe = sandbox_watchdog_probe,
+};
+device_platform_driver(sandbox_watchdog_drv);
diff --git a/arch/sandbox/dts/sandbox.dts b/arch/sandbox/dts/sandbox.dts
index be96745b4274..f830adecf796 100644
--- a/arch/sandbox/dts/sandbox.dts
+++ b/arch/sandbox/dts/sandbox.dts
@@ -54,4 +54,9 @@
compatible = "barebox,sandbox-power";
barebox,reset-source = <&stickypage 0>;
};
+
+ watchdog {
+ compatible = "barebox,sandbox-watchdog";
+ barebox,reset-source = <&stickypage 0>;
+ };
};
diff --git a/arch/sandbox/mach-sandbox/include/mach/linux.h b/arch/sandbox/mach-sandbox/include/mach/linux.h
index 7bb022a6de1d..b26bfc24a291 100644
--- a/arch/sandbox/mach-sandbox/include/mach/linux.h
+++ b/arch/sandbox/mach-sandbox/include/mach/linux.h
@@ -25,6 +25,8 @@ void linux_reexec(void);
int linux_execve(const char * filename, char *const argv[], char *const envp[]);
+int linux_watchdog_set_timeout(unsigned int timeout);
+
int barebox_register_console(int stdinfd, int stdoutfd);
int barebox_register_dtb(const void *dtb);
diff --git a/arch/sandbox/os/common.c b/arch/sandbox/os/common.c
index 54d2b97b4af7..da87be29c74d 100644
--- a/arch/sandbox/os/common.c
+++ b/arch/sandbox/os/common.c
@@ -39,6 +39,8 @@
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <linux/fs.h>
+#include <sys/time.h>
+#include <signal.h>
/*
* ...except the ones needed to connect with barebox
*/
@@ -244,6 +246,29 @@ int linux_execve(const char * filename, char *const argv[], char *const envp[])
}
}
+static void linux_watchdog(int signo)
+{
+ linux_reexec();
+ _exit(0);
+}
+
+int linux_watchdog_set_timeout(unsigned int timeout)
+{
+ static int signal_handler_installed;
+
+ if (!signal_handler_installed) {
+ struct sigaction sact = {
+ .sa_flags = SA_NODEFER, .sa_handler = linux_watchdog
+ };
+
+ sigemptyset(&sact.sa_mask);
+ sigaction(SIGALRM, &sact, NULL);
+ signal_handler_installed = 1;
+ }
+
+ return alarm(timeout);
+}
+
extern void start_barebox(void);
extern void mem_malloc_init(void *start, void *end);
--
2.28.0
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