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linux/drivers/watchdog/sunxi_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

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* sunxi Watchdog Driver
*
* Copyright (c) 2013 Carlo Caione
* 2012 Henrik Nordstrom
*
* Based on xen_wdt.c
* (c) Copyright 2010 Novell, Inc.
*/
#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 WDT_MAX_TIMEOUT 16
#define WDT_MIN_TIMEOUT 1
#define WDT_TIMEOUT_MASK 0x0F
#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
#define WDT_MODE_EN (1 << 0)
#define DRV_NAME "sunxi-wdt"
#define DRV_VERSION "1.0"
static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int timeout;
/*
* This structure stores the register offsets for different variants
* of Allwinner's watchdog hardware.
*/
struct sunxi_wdt_reg {
u8 wdt_ctrl;
u8 wdt_cfg;
u8 wdt_mode;
u8 wdt_timeout_shift;
u8 wdt_reset_mask;
u8 wdt_reset_val;
};
struct sunxi_wdt_dev {
struct watchdog_device wdt_dev;
void __iomem *wdt_base;
const struct sunxi_wdt_reg *wdt_regs;
};
/*
* wdt_timeout_map maps the watchdog timer interval value in seconds to
* the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3
*
* [timeout seconds] = register value
*
*/
static const int wdt_timeout_map[] = {
[1] = 0x1, /* 1s */
[2] = 0x2, /* 2s */
[3] = 0x3, /* 3s */
[4] = 0x4, /* 4s */
[5] = 0x5, /* 5s */
[6] = 0x6, /* 6s */
[8] = 0x7, /* 8s */
[10] = 0x8, /* 10s */
[12] = 0x9, /* 12s */
[14] = 0xA, /* 14s */
[16] = 0xB, /* 16s */
};
static int sunxi_wdt_restart(struct watchdog_device *wdt_dev,
unsigned long action, void *data)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
u32 val;
/* Set system reset function */
val = readl(wdt_base + regs->wdt_cfg);
val &= ~(regs->wdt_reset_mask);
val |= regs->wdt_reset_val;
writel(val, wdt_base + regs->wdt_cfg);
/* Set lowest timeout and enable watchdog */
val = readl(wdt_base + regs->wdt_mode);
val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
val |= WDT_MODE_EN;
writel(val, wdt_base + regs->wdt_mode);
/*
* Restart the watchdog. The default (and lowest) interval
* value for the watchdog is 0.5s.
*/
writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
while (1) {
mdelay(5);
val = readl(wdt_base + regs->wdt_mode);
val |= WDT_MODE_EN;
writel(val, wdt_base + regs->wdt_mode);
}
return 0;
}
static int sunxi_wdt_ping(struct watchdog_device *wdt_dev)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl);
return 0;
}
static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
u32 reg;
if (wdt_timeout_map[timeout] == 0)
timeout++;
sunxi_wdt->wdt_dev.timeout = timeout;
reg = readl(wdt_base + regs->wdt_mode);
reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift);
reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift;
writel(reg, wdt_base + regs->wdt_mode);
sunxi_wdt_ping(wdt_dev);
return 0;
}
static int sunxi_wdt_stop(struct watchdog_device *wdt_dev)
{
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
writel(0, wdt_base + regs->wdt_mode);
return 0;
}
static int sunxi_wdt_start(struct watchdog_device *wdt_dev)
{
u32 reg;
struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev);
void __iomem *wdt_base = sunxi_wdt->wdt_base;
const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs;
int ret;
ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev,
sunxi_wdt->wdt_dev.timeout);
if (ret < 0)
return ret;
/* Set system reset function */
reg = readl(wdt_base + regs->wdt_cfg);
reg &= ~(regs->wdt_reset_mask);
reg |= regs->wdt_reset_val;
writel(reg, wdt_base + regs->wdt_cfg);
/* Enable watchdog */
reg = readl(wdt_base + regs->wdt_mode);
reg |= WDT_MODE_EN;
writel(reg, wdt_base + regs->wdt_mode);
return 0;
}
static const struct watchdog_info sunxi_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops sunxi_wdt_ops = {
.owner = THIS_MODULE,
.start = sunxi_wdt_start,
.stop = sunxi_wdt_stop,
.ping = sunxi_wdt_ping,
.set_timeout = sunxi_wdt_set_timeout,
.restart = sunxi_wdt_restart,
};
static const struct sunxi_wdt_reg sun4i_wdt_reg = {
.wdt_ctrl = 0x00,
.wdt_cfg = 0x04,
.wdt_mode = 0x04,
.wdt_timeout_shift = 3,
.wdt_reset_mask = 0x02,
.wdt_reset_val = 0x02,
};
static const struct sunxi_wdt_reg sun6i_wdt_reg = {
.wdt_ctrl = 0x10,
.wdt_cfg = 0x14,
.wdt_mode = 0x18,
.wdt_timeout_shift = 4,
.wdt_reset_mask = 0x03,
.wdt_reset_val = 0x01,
};
static const struct of_device_id sunxi_wdt_dt_ids[] = {
{ .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg },
{ .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids);
static int sunxi_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct sunxi_wdt_dev *sunxi_wdt;
int err;
sunxi_wdt = devm_kzalloc(dev, sizeof(*sunxi_wdt), GFP_KERNEL);
if (!sunxi_wdt)
return -EINVAL;
sunxi_wdt->wdt_regs = of_device_get_match_data(dev);
if (!sunxi_wdt->wdt_regs)
return -ENODEV;
sunxi_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(sunxi_wdt->wdt_base))
return PTR_ERR(sunxi_wdt->wdt_base);
sunxi_wdt->wdt_dev.info = &sunxi_wdt_info;
sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops;
sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT;
sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT;
sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT;
sunxi_wdt->wdt_dev.parent = dev;
watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, dev);
watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout);
watchdog_set_restart_priority(&sunxi_wdt->wdt_dev, 128);
watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt);
sunxi_wdt_stop(&sunxi_wdt->wdt_dev);
watchdog_stop_on_reboot(&sunxi_wdt->wdt_dev);
err = devm_watchdog_register_device(dev, &sunxi_wdt->wdt_dev);
if (unlikely(err))
return err;
dev_info(dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
sunxi_wdt->wdt_dev.timeout, nowayout);
return 0;
}
static struct platform_driver sunxi_wdt_driver = {
.probe = sunxi_wdt_probe,
.driver = {
.name = DRV_NAME,
.of_match_table = sunxi_wdt_dt_ids,
},
};
module_platform_driver(sunxi_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@gmail.com>");
MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
MODULE_VERSION(DRV_VERSION);
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