Add watchdog timer support for the Congatec Board Controller.
Signed-off-by: Thomas Richard <thomas.richard@xxxxxxxxxxx>
---
drivers/watchdog/Kconfig | 10 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/cgbc_wdt.c | 211 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 222 insertions(+)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index bae1d97cce89..07b711fc8bb2 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1142,6 +1142,16 @@ config ALIM7101_WDT
Most people will say N.
+config CGBC_WDT
+ tristate "Congatec Board Controller Watchdog Timer"
+ depends on MFD_CGBC
+ select WATCHDOG_CORE
+ help
+ Enables watchdog timer support for the Congatec Board Controller.
+
+ This driver can also be built as a module. If so, the module will be
+ called cgbc_wdt.
+
config EBC_C384_WDT
tristate "WinSystems EBC-C384 Watchdog Timer"
depends on (X86 || COMPILE_TEST) && HAS_IOPORT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index b51030f035a6..5aa66ba91346 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
obj-$(CONFIG_ADVANTECH_EC_WDT) += advantech_ec_wdt.o
obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o
obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o
+obj-$(CONFIG_CGBC_WDT) += cgbc_wdt.o
obj-$(CONFIG_EBC_C384_WDT) += ebc-c384_wdt.o
obj-$(CONFIG_EXAR_WDT) += exar_wdt.o
obj-$(CONFIG_F71808E_WDT) += f71808e_wdt.o
diff --git a/drivers/watchdog/cgbc_wdt.c b/drivers/watchdog/cgbc_wdt.c
new file mode 100644
index 000000000000..702b055ba6f4
--- /dev/null
+++ b/drivers/watchdog/cgbc_wdt.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Congatec Board Controller watchdog driver
+ *
+ * Copyright (C) 2024 Bootlin
+ * Author: Thomas Richard <thomas.richard@xxxxxxxxxxx>
+ */
+
+#include <linux/build_bug.h>
+#include <linux/device.h>
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#include <linux/mfd/cgbc.h>
+
+#define CGBC_WDT_CMD_TRIGGER 0x27
+#define CGBC_WDT_CMD_INIT 0x28
+#define CGBC_WDT_DISABLE 0x00
+
+#define CGBC_WDT_MODE_SINGLE_EVENT 0x02
+
+#define CGBC_WDT_MIN_TIMEOUT 1
+#define CGBC_WDT_MAX_TIMEOUT ((U32_MAX >> 8) / 1000)
+
+#define CGBC_WDT_DEFAULT_TIMEOUT 30
+#define CGBC_WDT_DEFAULT_PRETIMEOUT 0
+
+enum action {
+ ACTION_INT = 0,
+ ACTION_SMI,
+ ACTION_RESET,
+ ACTION_BUTTON,
+};
+
+static unsigned int timeout;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. (>=0, default="
+ __MODULE_STRING(CGBC_WDT_DEFAULT_TIMEOUT) ")");
+
+static unsigned int pretimeout = CGBC_WDT_DEFAULT_PRETIMEOUT;
+module_param(pretimeout, uint, 0);
+MODULE_PARM_DESC(pretimeout,
+ "Watchdog pretimeout in seconds. (>=0, default="
+ __MODULE_STRING(CGBC_WDT_DEFAULT_PRETIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct cgbc_wdt_data {
+ struct cgbc_device_data *cgbc;
+ struct watchdog_device wdd;
+};
+
+struct cgbc_wdt_cmd_cfg {
+ u8 cmd;
+ u8 mode;
+ u8 action;
+ u8 timeout1[3];
+ u8 timeout2[3];
+ u8 reserved[3];
+ u8 delay[3];
+} __packed;
+
+static_assert(sizeof(struct cgbc_wdt_cmd_cfg) == 15);
+
+static int cgbc_wdt_start(struct watchdog_device *wdd)
+{
+ struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+ struct cgbc_device_data *cgbc = wdt_data->cgbc;
+ unsigned int timeout1 = (wdd->timeout - wdd->pretimeout) * 1000;
+ unsigned int timeout2 = wdd->pretimeout * 1000;
+ u8 action;
+
+ struct cgbc_wdt_cmd_cfg cmd_start = {
+ .cmd = CGBC_WDT_CMD_INIT,
+ .mode = CGBC_WDT_MODE_SINGLE_EVENT,
+ .timeout1[0] = (u8)timeout1,
+ .timeout1[1] = (u8)(timeout1 >> 8),
+ .timeout1[2] = (u8)(timeout1 >> 16),
+ .timeout2[0] = (u8)timeout2,
+ .timeout2[1] = (u8)(timeout2 >> 8),
+ .timeout2[2] = (u8)(timeout2 >> 16),
+ };
+
+ if (wdd->pretimeout) {
+ action = 2;
+ action |= ACTION_SMI << 2;
+ action |= ACTION_RESET << 4;
+ } else {
+ action = 1;
+ action |= ACTION_RESET << 2;
+ }
+
+ cmd_start.action = action;
+
+ return cgbc_command(cgbc, &cmd_start, sizeof(cmd_start), NULL, 0, NULL);
+}
+
+static int cgbc_wdt_stop(struct watchdog_device *wdd)
+{
+ struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+ struct cgbc_device_data *cgbc = wdt_data->cgbc;
+ struct cgbc_wdt_cmd_cfg cmd_stop = {
+ .cmd = CGBC_WDT_CMD_INIT,
+ .mode = CGBC_WDT_DISABLE,
+ };
+
+ return cgbc_command(cgbc, &cmd_stop, sizeof(cmd_stop), NULL, 0, NULL);
+}
+
+static int cgbc_wdt_keepalive(struct watchdog_device *wdd)
+{
+ struct cgbc_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
+ struct cgbc_device_data *cgbc = wdt_data->cgbc;
+ u8 cmd_ping = CGBC_WDT_CMD_TRIGGER;
+
+ return cgbc_command(cgbc, &cmd_ping, sizeof(cmd_ping), NULL, 0, NULL);
+}
+
+static int cgbc_wdt_set_pretimeout(struct watchdog_device *wdd,
+ unsigned int pretimeout)
+{
+ wdd->pretimeout = pretimeout;
+
+ if (watchdog_active(wdd))
+ return cgbc_wdt_start(wdd);
+
+ return 0;
+}
+
+static int cgbc_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ if (timeout < wdd->pretimeout)
+ wdd->pretimeout = 0;
+
+ wdd->timeout = timeout;
+
+ if (watchdog_active(wdd))
+ return cgbc_wdt_start(wdd);
+
+ return 0;
+}
+
+static const struct watchdog_info cgbc_wdt_info = {
+ .identity = "CGBC Watchdog",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT
+};
+
+static const struct watchdog_ops cgbc_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = cgbc_wdt_start,
+ .stop = cgbc_wdt_stop,
+ .ping = cgbc_wdt_keepalive,
+ .set_timeout = cgbc_wdt_set_timeout,
+ .set_pretimeout = cgbc_wdt_set_pretimeout,
+};
+
+static int cgbc_wdt_probe(struct platform_device *pdev)
+{
+ struct cgbc_device_data *cgbc = dev_get_drvdata(pdev->dev.parent);
+ struct device *dev = &pdev->dev;
+ struct cgbc_wdt_data *wdt_data;
+ struct watchdog_device *wdd;
+
+ wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL);
+ if (!wdt_data)
+ return -ENOMEM;
+
+ wdt_data->cgbc = cgbc;
+ wdd = &wdt_data->wdd;
+ wdd->parent = dev;
+
+ wdd->info = &cgbc_wdt_info;
+ wdd->ops = &cgbc_wdt_ops;
+ wdd->max_timeout = CGBC_WDT_MAX_TIMEOUT;
+ wdd->min_timeout = CGBC_WDT_MIN_TIMEOUT;
+
+ watchdog_set_drvdata(wdd, wdt_data);
+ watchdog_set_nowayout(wdd, nowayout);
+
+ wdd->timeout = CGBC_WDT_DEFAULT_TIMEOUT;
+ watchdog_init_timeout(wdd, timeout, dev);
+ cgbc_wdt_set_pretimeout(wdd, pretimeout);
+
+ platform_set_drvdata(pdev, wdt_data);
+ watchdog_stop_on_reboot(wdd);
+ watchdog_stop_on_unregister(wdd);
+
+ return devm_watchdog_register_device(dev, wdd);
+}
+
+static struct platform_driver cgbc_wdt_driver = {
+ .driver = {
+ .name = "cgbc-wdt",
+ },
+ .probe = cgbc_wdt_probe,
+};
+
+module_platform_driver(cgbc_wdt_driver);
+
+MODULE_DESCRIPTION("Congatec Board Controller Watchdog Driver");
+MODULE_AUTHOR("Thomas Richard <thomas.richard@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
2.39.5
