Release 4.12 drivers/watchdog/sunxi_wdt.c
  
  
  
/*
 *      sunxi Watchdog Driver
 *
 *      Copyright (c) 2013 Carlo Caione
 *                    2012 Henrik Nordstrom
 *
 *      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.
 *
 *      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 = WDT_MAX_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Chen-Yu Tsai | 103 | 57.54% | 1 | 20.00% | 
| Maxime Ripard | 38 | 21.23% | 1 | 20.00% | 
| Guenter Roeck | 32 | 17.88% | 2 | 40.00% | 
| Damien Riegel | 6 | 3.35% | 1 | 20.00% | 
| Total | 179 | 100.00% | 5 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Carlo Caione | 40 | 74.07% | 1 | 50.00% | 
| Chen-Yu Tsai | 14 | 25.93% | 1 | 50.00% | 
| Total | 54 | 100.00% | 2 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Carlo Caione | 91 | 76.47% | 1 | 50.00% | 
| Chen-Yu Tsai | 28 | 23.53% | 1 | 50.00% | 
| Total | 119 | 100.00% | 2 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Carlo Caione | 40 | 74.07% | 1 | 50.00% | 
| Chen-Yu Tsai | 14 | 25.93% | 1 | 50.00% | 
| Total | 54 | 100.00% | 2 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Carlo Caione | 81 | 58.27% | 1 | 50.00% | 
| Chen-Yu Tsai | 58 | 41.73% | 1 | 50.00% | 
| Total | 139 | 100.00% | 2 | 100.00% | 
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 sunxi_wdt_dev *sunxi_wdt;
	const struct of_device_id *device;
	struct resource *res;
	int err;
	sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL);
	if (!sunxi_wdt)
		return -EINVAL;
	device = of_match_device(sunxi_wdt_dt_ids, &pdev->dev);
	if (!device)
		return -ENODEV;
	sunxi_wdt->wdt_regs = device->data;
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
	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 = &pdev->dev;
	watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->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(&pdev->dev, &sunxi_wdt->wdt_dev);
	if (unlikely(err))
		return err;
	dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
			sunxi_wdt->wdt_dev.timeout, nowayout);
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Carlo Caione | 229 | 79.51% | 1 | 25.00% | 
| Chen-Yu Tsai | 35 | 12.15% | 1 | 25.00% | 
| Guenter Roeck | 14 | 4.86% | 1 | 25.00% | 
| Damien Riegel | 10 | 3.47% | 1 | 25.00% | 
| Total | 288 | 100.00% | 4 | 100.00% | 
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);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Carlo Caione | 784 | 59.30% | 1 | 10.00% | 
| Chen-Yu Tsai | 409 | 30.94% | 2 | 20.00% | 
| Guenter Roeck | 50 | 3.78% | 3 | 30.00% | 
| Maxime Ripard | 45 | 3.40% | 1 | 10.00% | 
| Damien Riegel | 21 | 1.59% | 1 | 10.00% | 
| Emilio López | 11 | 0.83% | 1 | 10.00% | 
| Sachin Kamat | 2 | 0.15% | 1 | 10.00% | 
| Total | 1322 | 100.00% | 10 | 100.00% | 
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