linux/drivers/watchdog/meson_wdt.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

233 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Meson Watchdog Driver
*
* Copyright (c) 2014 Carlo Caione
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#define DRV_NAME "meson_wdt"
#define MESON_WDT_TC 0x00
#define MESON_WDT_DC_RESET (3 << 24)
#define MESON_WDT_RESET 0x04
#define MESON_WDT_TIMEOUT 30
#define MESON_WDT_MIN_TIMEOUT 1
#define MESON_SEC_TO_TC(s, c) ((s) * (c))
static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int timeout;
struct meson_wdt_data {
unsigned int enable;
unsigned int terminal_count_mask;
unsigned int count_unit;
};
static struct meson_wdt_data meson6_wdt_data = {
.enable = BIT(22),
.terminal_count_mask = 0x3fffff,
.count_unit = 100000, /* 10 us */
};
static struct meson_wdt_data meson8b_wdt_data = {
.enable = BIT(19),
.terminal_count_mask = 0xffff,
.count_unit = 7812, /* 128 us */
};
struct meson_wdt_dev {
struct watchdog_device wdt_dev;
void __iomem *wdt_base;
const struct meson_wdt_data *data;
};
static int meson_wdt_restart(struct watchdog_device *wdt_dev,
unsigned long action, void *data)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 tc_reboot = MESON_WDT_DC_RESET;
tc_reboot |= meson_wdt->data->enable;
while (1) {
writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
mdelay(5);
}
return 0;
}
static int meson_wdt_ping(struct watchdog_device *wdt_dev)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
return 0;
}
static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 reg;
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
reg &= ~meson_wdt->data->terminal_count_mask;
reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
}
static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
wdt_dev->timeout = timeout;
meson_wdt_change_timeout(wdt_dev, timeout);
meson_wdt_ping(wdt_dev);
return 0;
}
static int meson_wdt_stop(struct watchdog_device *wdt_dev)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 reg;
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
reg &= ~meson_wdt->data->enable;
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
return 0;
}
static int meson_wdt_start(struct watchdog_device *wdt_dev)
{
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
u32 reg;
meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
meson_wdt_ping(wdt_dev);
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
reg |= meson_wdt->data->enable;
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
return 0;
}
static const struct watchdog_info meson_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops meson_wdt_ops = {
.owner = THIS_MODULE,
.start = meson_wdt_start,
.stop = meson_wdt_stop,
.ping = meson_wdt_ping,
.set_timeout = meson_wdt_set_timeout,
.restart = meson_wdt_restart,
};
static const struct of_device_id meson_wdt_dt_ids[] = {
{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
{ .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
{ .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
static int meson_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct meson_wdt_dev *meson_wdt;
const struct of_device_id *of_id;
int err;
meson_wdt = devm_kzalloc(dev, sizeof(*meson_wdt), GFP_KERNEL);
if (!meson_wdt)
return -ENOMEM;
meson_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(meson_wdt->wdt_base))
return PTR_ERR(meson_wdt->wdt_base);
of_id = of_match_device(meson_wdt_dt_ids, dev);
if (!of_id) {
dev_err(dev, "Unable to initialize WDT data\n");
return -ENODEV;
}
meson_wdt->data = of_id->data;
meson_wdt->wdt_dev.parent = dev;
meson_wdt->wdt_dev.info = &meson_wdt_info;
meson_wdt->wdt_dev.ops = &meson_wdt_ops;
meson_wdt->wdt_dev.max_timeout =
meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
meson_wdt->wdt_dev.timeout = min_t(unsigned int,
MESON_WDT_TIMEOUT,
meson_wdt->wdt_dev.max_timeout);
watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, dev);
watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
meson_wdt_stop(&meson_wdt->wdt_dev);
watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
err = devm_watchdog_register_device(dev, &meson_wdt->wdt_dev);
if (err)
return err;
dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
meson_wdt->wdt_dev.timeout, nowayout);
return 0;
}
static struct platform_driver meson_wdt_driver = {
.probe = meson_wdt_probe,
.driver = {
.name = DRV_NAME,
.of_match_table = meson_wdt_dt_ids,
},
};
module_platform_driver(meson_wdt_driver);
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
MODULE_DESCRIPTION("Meson Watchdog Timer Driver");