--- /dev/null
+ Mellanox watchdog drivers
+ for x86 based system switches
+
+This driver provides watchdog functionality for various Mellanox
+Ethernet and Infiniband switch systems.
+
+Mellanox watchdog device is implemented in a programmable logic device.
+
+There are 2 types of HW watchdog implementations.
+
+Type 1:
+Actual HW timeout can be defined as a power of 2 msec.
+e.g. timeout 20 sec will be rounded up to 32768 msec.
+The maximum timeout period is 32 sec (32768 msec.),
+Get time-left isn't supported
+
+Type 2:
+Actual HW timeout is defined in sec. and it's the same as
+a user-defined timeout.
+Maximum timeout is 255 sec.
+Get time-left is supported.
+
+Type 1 HW watchdog implementation exist in old systems and
+all new systems have type 2 HW watchdog.
+Two types of HW implementation have also different register map.
+
+Mellanox system can have 2 watchdogs: main and auxiliary.
+Main and auxiliary watchdog devices can be enabled together
+on the same system.
+There are several actions that can be defined in the watchdog:
+system reset, start fans on full speed and increase register counter.
+The last 2 actions are performed without a system reset.
+Actions without reset are provided for auxiliary watchdog device,
+which is optional.
+Watchdog can be started during a probe, in this case it will be
+pinged by watchdog core before watchdog device will be opened by
+user space application.
+Watchdog can be initialised in nowayout way, i.e. oncse started
+it can't be stopped.
+
+This mlx-wdt driver supports both HW watchdog implementations.
+
+Watchdog driver is probed from the common mlx_platform driver.
+Mlx_platform driver provides an appropriate set of registers for
+Mellanox watchdog device, identity name (mlx-wdt-main or mlx-wdt-aux),
+initial timeout, performed action in expiration and configuration flags.
+watchdog configuration flags: nowayout and start_at_boot, hw watchdog
+version - type1 or type2.
+The driver checks during initialization if the previous system reset
+was done by the watchdog. If yes, it makes a notification about this event.
+
+Access to HW registers is performed through a generic regmap interface.
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Mellanox watchdog driver
+ *
+ * Copyright (C) 2019 Mellanox Technologies
+ * Copyright (C) 2019 Michael Shych <mshych@mellanox.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/platform_data/mlxreg.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+#define MLXREG_WDT_CLOCK_SCALE 1000
+#define MLXREG_WDT_MAX_TIMEOUT_TYPE1 32
+#define MLXREG_WDT_MAX_TIMEOUT_TYPE2 255
+#define MLXREG_WDT_MIN_TIMEOUT 1
+#define MLXREG_WDT_OPTIONS_BASE (WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | \
+ WDIOF_SETTIMEOUT)
+
+/**
+ * struct mlxreg_wdt - wd private data:
+ *
+ * @wdd: watchdog device;
+ * @device: basic device;
+ * @pdata: data received from platform driver;
+ * @regmap: register map of parent device;
+ * @timeout: defined timeout in sec.;
+ * @action_idx: index for direct access to action register;
+ * @timeout_idx:index for direct access to TO register;
+ * @tleft_idx: index for direct access to time left register;
+ * @ping_idx: index for direct access to ping register;
+ * @reset_idx: index for direct access to reset cause register;
+ * @wd_type: watchdog HW type;
+ */
+struct mlxreg_wdt {
+ struct watchdog_device wdd;
+ struct mlxreg_core_platform_data *pdata;
+ void *regmap;
+ int action_idx;
+ int timeout_idx;
+ int tleft_idx;
+ int ping_idx;
+ int reset_idx;
+ enum mlxreg_wdt_type wdt_type;
+};
+
+static void mlxreg_wdt_check_card_reset(struct mlxreg_wdt *wdt)
+{
+ struct mlxreg_core_data *reg_data;
+ u32 regval;
+ int rc;
+
+ if (wdt->reset_idx == -EINVAL)
+ return;
+
+ if (!(wdt->wdd.info->options & WDIOF_CARDRESET))
+ return;
+
+ reg_data = &wdt->pdata->data[wdt->reset_idx];
+ rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
+ if (!rc) {
+ if (regval & ~reg_data->mask) {
+ wdt->wdd.bootstatus = WDIOF_CARDRESET;
+ dev_info(wdt->wdd.parent,
+ "watchdog previously reset the CPU\n");
+ }
+ }
+}
+
+static int mlxreg_wdt_start(struct watchdog_device *wdd)
+{
+ struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
+ struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx];
+
+ return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
+ BIT(reg_data->bit));
+}
+
+static int mlxreg_wdt_stop(struct watchdog_device *wdd)
+{
+ struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
+ struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx];
+
+ return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
+ ~BIT(reg_data->bit));
+}
+
+static int mlxreg_wdt_ping(struct watchdog_device *wdd)
+{
+ struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
+ struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->ping_idx];
+
+ return regmap_update_bits_base(wdt->regmap, reg_data->reg,
+ ~reg_data->mask, BIT(reg_data->bit),
+ NULL, false, true);
+}
+
+static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
+ struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->timeout_idx];
+ u32 regval, set_time, hw_timeout;
+ int rc;
+
+ if (wdt->wdt_type == MLX_WDT_TYPE1) {
+ rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
+ if (rc)
+ return rc;
+
+ hw_timeout = order_base_2(timeout * MLXREG_WDT_CLOCK_SCALE);
+ regval = (regval & reg_data->mask) | hw_timeout;
+ /* Rowndown to actual closest number of sec. */
+ set_time = BIT(hw_timeout) / MLXREG_WDT_CLOCK_SCALE;
+ } else {
+ set_time = timeout;
+ regval = timeout;
+ }
+
+ wdd->timeout = set_time;
+ rc = regmap_write(wdt->regmap, reg_data->reg, regval);
+
+ if (!rc) {
+ /*
+ * Restart watchdog with new timeout period
+ * if watchdog is already started.
+ */
+ if (watchdog_active(wdd)) {
+ rc = mlxreg_wdt_stop(wdd);
+ if (!rc)
+ rc = mlxreg_wdt_start(wdd);
+ }
+ }
+
+ return rc;
+}
+
+static unsigned int mlxreg_wdt_get_timeleft(struct watchdog_device *wdd)
+{
+ struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd);
+ struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->tleft_idx];
+ u32 regval;
+ int rc;
+
+ rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
+ /* Return 0 timeleft in case of failure register read. */
+ return rc == 0 ? regval : 0;
+}
+
+static const struct watchdog_ops mlxreg_wdt_ops_type1 = {
+ .start = mlxreg_wdt_start,
+ .stop = mlxreg_wdt_stop,
+ .ping = mlxreg_wdt_ping,
+ .set_timeout = mlxreg_wdt_set_timeout,
+ .owner = THIS_MODULE,
+};
+
+static const struct watchdog_ops mlxreg_wdt_ops_type2 = {
+ .start = mlxreg_wdt_start,
+ .stop = mlxreg_wdt_stop,
+ .ping = mlxreg_wdt_ping,
+ .set_timeout = mlxreg_wdt_set_timeout,
+ .get_timeleft = mlxreg_wdt_get_timeleft,
+ .owner = THIS_MODULE,
+};
+
+static const struct watchdog_info mlxreg_wdt_main_info = {
+ .options = MLXREG_WDT_OPTIONS_BASE
+ | WDIOF_CARDRESET,
+ .identity = "mlx-wdt-main",
+};
+
+static const struct watchdog_info mlxreg_wdt_aux_info = {
+ .options = MLXREG_WDT_OPTIONS_BASE
+ | WDIOF_ALARMONLY,
+ .identity = "mlx-wdt-aux",
+};
+
+static void mlxreg_wdt_config(struct mlxreg_wdt *wdt,
+ struct mlxreg_core_platform_data *pdata)
+{
+ struct mlxreg_core_data *data = pdata->data;
+ int i;
+
+ wdt->reset_idx = -EINVAL;
+ for (i = 0; i < pdata->counter; i++, data++) {
+ if (strnstr(data->label, "action", sizeof(data->label)))
+ wdt->action_idx = i;
+ else if (strnstr(data->label, "timeout", sizeof(data->label)))
+ wdt->timeout_idx = i;
+ else if (strnstr(data->label, "timeleft", sizeof(data->label)))
+ wdt->tleft_idx = i;
+ else if (strnstr(data->label, "ping", sizeof(data->label)))
+ wdt->ping_idx = i;
+ else if (strnstr(data->label, "reset", sizeof(data->label)))
+ wdt->reset_idx = i;
+ }
+
+ wdt->pdata = pdata;
+ if (strnstr(pdata->identity, mlxreg_wdt_main_info.identity,
+ sizeof(mlxreg_wdt_main_info.identity)))
+ wdt->wdd.info = &mlxreg_wdt_main_info;
+ else
+ wdt->wdd.info = &mlxreg_wdt_aux_info;
+
+ wdt->wdt_type = pdata->version;
+ if (wdt->wdt_type == MLX_WDT_TYPE2) {
+ wdt->wdd.ops = &mlxreg_wdt_ops_type2;
+ wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2;
+ } else {
+ wdt->wdd.ops = &mlxreg_wdt_ops_type1;
+ wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1;
+ }
+ wdt->wdd.min_timeout = MLXREG_WDT_MIN_TIMEOUT;
+}
+
+static int mlxreg_wdt_init_timeout(struct mlxreg_wdt *wdt,
+ struct mlxreg_core_platform_data *pdata)
+{
+ u32 timeout;
+
+ timeout = pdata->data[wdt->timeout_idx].health_cntr;
+ return mlxreg_wdt_set_timeout(&wdt->wdd, timeout);
+}
+
+static int mlxreg_wdt_probe(struct platform_device *pdev)
+{
+ struct mlxreg_core_platform_data *pdata;
+ struct mlxreg_wdt *wdt;
+ int rc;
+
+ pdata = dev_get_platdata(&pdev->dev);
+ if (!pdata) {
+ dev_err(&pdev->dev, "Failed to get platform data.\n");
+ return -EINVAL;
+ }
+ wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ wdt->wdd.parent = &pdev->dev;
+ wdt->regmap = pdata->regmap;
+ mlxreg_wdt_config(wdt, pdata);
+
+ if ((pdata->features & MLXREG_CORE_WD_FEATURE_NOWAYOUT))
+ watchdog_set_nowayout(&wdt->wdd, WATCHDOG_NOWAYOUT);
+ watchdog_stop_on_reboot(&wdt->wdd);
+ watchdog_stop_on_unregister(&wdt->wdd);
+ watchdog_set_drvdata(&wdt->wdd, wdt);
+ rc = mlxreg_wdt_init_timeout(wdt, pdata);
+ if (rc)
+ goto register_error;
+
+ if ((pdata->features & MLXREG_CORE_WD_FEATURE_START_AT_BOOT)) {
+ rc = mlxreg_wdt_start(&wdt->wdd);
+ if (rc)
+ goto register_error;
+ set_bit(WDOG_HW_RUNNING, &wdt->wdd.status);
+ }
+ mlxreg_wdt_check_card_reset(wdt);
+ rc = devm_watchdog_register_device(&pdev->dev, &wdt->wdd);
+
+register_error:
+ if (rc)
+ dev_err(&pdev->dev,
+ "Cannot register watchdog device (err=%d)\n", rc);
+ return rc;
+}
+
+static struct platform_driver mlxreg_wdt_driver = {
+ .probe = mlxreg_wdt_probe,
+ .driver = {
+ .name = "mlx-wdt",
+ },
+};
+
+module_platform_driver(mlxreg_wdt_driver);
+
+MODULE_AUTHOR("Michael Shych <michaelsh@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mlx-wdt");
projects / linux-2.6-block.git / commitdiff