// 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_MAX_TIMEOUT_TYPE3 65535
#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;
* @pdata: data received from platform driver;
* @regmap: register map of parent device;
* @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;
* @regmap_val_sz: size of value in register map;
* @wdt_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;
int regmap_val_sz;
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_write_bits(wdt->regmap, reg_data->reg, ~reg_data->mask,
BIT(reg_data->bit));
}
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;
switch (wdt->wdt_type) {
case 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;
rc = regmap_write(wdt->regmap, reg_data->reg, regval);
break;
case MLX_WDT_TYPE2:
set_time = timeout;
rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
break;
case MLX_WDT_TYPE3:
/* WD_TYPE3 has 2B set time register */
set_time = timeout;
if (wdt->regmap_val_sz == 1) {
regval = timeout & 0xff;
rc = regmap_write(wdt->regmap, reg_data->reg, regval);
if (!rc) {
regval = (timeout & 0xff00) >> 8;
rc = regmap_write(wdt->regmap,
reg_data->reg + 1, regval);
}
} else {
rc = regmap_write(wdt->regmap, reg_data->reg, timeout);
}
break;
default:
return -EINVAL;
}
wdd->timeout = set_time;
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, msb, lsb;
int rc;
if (wdt->wdt_type == MLX_WDT_TYPE2) {
rc = regmap_read(wdt->regmap, reg_data->reg, ®val);
} else {
/* WD_TYPE3 has 2 byte timeleft register */
if (wdt->regmap_val_sz == 1) {
rc = regmap_read(wdt->regmap, reg_data->reg, &lsb);
if (!rc) {
rc = regmap_read(wdt->regmap,
reg_data->reg + 1, &msb);
regval = (msb & 0xff) << 8 | (lsb & 0xff);
}
} else {
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;
switch (wdt->wdt_type) {
case MLX_WDT_TYPE1:
wdt->wdd.ops = &mlxreg_wdt_ops_type1;
wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1;
break;
case MLX_WDT_TYPE2:
wdt->wdd.ops = &mlxreg_wdt_ops_type2;
wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2;
break;
case MLX_WDT_TYPE3:
wdt->wdd.ops = &mlxreg_wdt_ops_type2;
wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE3;
break;
default:
break;
}
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 device *dev = &pdev->dev;
struct mlxreg_core_platform_data *pdata;
struct mlxreg_wdt *wdt;
int rc;
pdata = dev_get_platdata(dev);
if (!pdata) {
dev_err(dev, "Failed to get platform data.\n");
return -EINVAL;
}
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;
wdt->wdd.parent = dev;
wdt->regmap = pdata->regmap;
rc = regmap_get_val_bytes(wdt->regmap);
if (rc < 0)
return -EINVAL;
wdt->regmap_val_sz = rc;
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(dev, &wdt->wdd);
register_error:
if (rc)
dev_err(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");
