/*
 * Copyright (c) 2009 Nuvoton technology corporation.
 *
 * Wan ZongShun <mcuos.com@gmail.com>
 *
 * 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;version 2 of the License.
 *
 */

#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>

#define REG_WTCR		0x1c
#define WTCLK			(0x01 << 10)
#define WTE			(0x01 << 7)	/*wdt enable*/
#define WTIS			(0x03 << 4)
#define WTIF			(0x01 << 3)
#define WTRF			(0x01 << 2)
#define WTRE			(0x01 << 1)
#define WTR			(0x01 << 0)
/*
 * The watchdog time interval can be calculated via following formula:
 * WTIS		real time interval (formula)
 * 0x00		((2^ 14 ) * ((external crystal freq) / 256))seconds
 * 0x01		((2^ 16 ) * ((external crystal freq) / 256))seconds
 * 0x02		((2^ 18 ) * ((external crystal freq) / 256))seconds
 * 0x03		((2^ 20 ) * ((external crystal freq) / 256))seconds
 *
 * The external crystal freq is 15Mhz in the nuc900 evaluation board.
 * So 0x00 = +-0.28 seconds, 0x01 = +-1.12 seconds, 0x02 = +-4.48 seconds,
 * 0x03 = +- 16.92 seconds..
 */
#define WDT_HW_TIMEOUT		0x02
#define WDT_TIMEOUT		(HZ/2)
#define WDT_HEARTBEAT		15

static int heartbeat = WDT_HEARTBEAT;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
	"(default = " __MODULE_STRING(WDT_HEARTBEAT) ")");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

struct nuc900_wdt {
	struct clk	 *wdt_clock;
	struct platform_device *pdev;
	void __iomem	 *wdt_base;
	char		 expect_close;
	struct timer_list timer;
	spinlock_t       wdt_lock;
	unsigned long next_heartbeat;
};

static unsigned long nuc900wdt_busy;
static struct nuc900_wdt *nuc900_wdt;

static inline void nuc900_wdt_keepalive(void)
{
	unsigned int val;

	spin_lock(&nuc900_wdt->wdt_lock);

	val = __raw_readl(nuc900_wdt->wdt_base + REG_WTCR);
	val |= (WTR | WTIF);
	__raw_writel(val, nuc900_wdt->wdt_base + REG_WTCR);

	spin_unlock(&nuc900_wdt->wdt_lock);
}

static inline void nuc900_wdt_start(void)
{
	unsigned int val;

	spin_lock(&nuc900_wdt->wdt_lock);

	val = __raw_readl(nuc900_wdt->wdt_base + REG_WTCR);
	val |= (WTRE | WTE | WTR | WTCLK | WTIF);
	val &= ~WTIS;
	val |= (WDT_HW_TIMEOUT << 0x04);
	__raw_writel(val, nuc900_wdt->wdt_base + REG_WTCR);

	spin_unlock(&nuc900_wdt->wdt_lock);

	nuc900_wdt->next_heartbeat = jiffies + heartbeat * HZ;
	mod_timer(&nuc900_wdt->timer, jiffies + WDT_TIMEOUT);
}

static inline void nuc900_wdt_stop(void)
{
	unsigned int val;

	del_timer(&nuc900_wdt->timer);

	spin_lock(&nuc900_wdt->wdt_lock);

	val = __raw_readl(nuc900_wdt->wdt_base + REG_WTCR);
	val &= ~WTE;
	__raw_writel(val, nuc900_wdt->wdt_base + REG_WTCR);

	spin_unlock(&nuc900_wdt->wdt_lock);
}

static inline void nuc900_wdt_ping(void)
{
	nuc900_wdt->next_heartbeat = jiffies + heartbeat * HZ;
}

static int nuc900_wdt_open(struct inode *inode, struct file *file)
{

	if (test_and_set_bit(0, &nuc900wdt_busy))
		return -EBUSY;

	nuc900_wdt_start();

	return nonseekable_open(inode, file);
}

static int nuc900_wdt_close(struct inode *inode, struct file *file)
{
	if (nuc900_wdt->expect_close == 42)
		nuc900_wdt_stop();
	else {
		dev_crit(&nuc900_wdt->pdev->dev,
			"Unexpected close, not stopping watchdog!\n");
		nuc900_wdt_ping();
	}

	nuc900_wdt->expect_close = 0;
	clear_bit(0, &nuc900wdt_busy);
	return 0;
}

static const struct watchdog_info nuc900_wdt_info = {
	.identity	= "nuc900 watchdog",
	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
						WDIOF_MAGICCLOSE,
};

static long nuc900_wdt_ioctl(struct file *file,
					unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_value;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(argp, &nuc900_wdt_info,
				sizeof(nuc900_wdt_info)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_KEEPALIVE:
		nuc900_wdt_ping();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_value, p))
			return -EFAULT;

		heartbeat = new_value;
		nuc900_wdt_ping();

		return put_user(new_value, p);
	case WDIOC_GETTIMEOUT:
		return put_user(heartbeat, p);
	default:
		return -ENOTTY;
	}
}

static ssize_t nuc900_wdt_write(struct file *file, const char __user *data,
						size_t len, loff_t *ppos)
{
	if (!len)
		return 0;

	/* Scan for magic character */
	if (!nowayout) {
		size_t i;

		nuc900_wdt->expect_close = 0;

		for (i = 0; i < len; i++) {
			char c;
			if (get_user(c, data + i))
				return -EFAULT;
			if (c == 'V') {
				nuc900_wdt->expect_close = 42;
				break;
			}
		}
	}

	nuc900_wdt_ping();
	return len;
}

static void nuc900_wdt_timer_ping(unsigned long data)
{
	if (time_before(jiffies, nuc900_wdt->next_heartbeat)) {
		nuc900_wdt_keepalive();
		mod_timer(&nuc900_wdt->timer, jiffies + WDT_TIMEOUT);
	} else
		dev_warn(&nuc900_wdt->pdev->dev, "Will reset the machine !\n");
}

static const struct file_operations nuc900wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.unlocked_ioctl	= nuc900_wdt_ioctl,
	.open		= nuc900_wdt_open,
	.release	= nuc900_wdt_close,
	.write		= nuc900_wdt_write,
};

static struct miscdevice nuc900wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &nuc900wdt_fops,
};

static int nuc900wdt_probe(struct platform_device *pdev)
{
	struct resource *res;
	int ret = 0;

	nuc900_wdt = devm_kzalloc(&pdev->dev, sizeof(*nuc900_wdt),
				GFP_KERNEL);
	if (!nuc900_wdt)
		return -ENOMEM;

	nuc900_wdt->pdev = pdev;

	spin_lock_init(&nuc900_wdt->wdt_lock);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	nuc900_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(nuc900_wdt->wdt_base))
		return PTR_ERR(nuc900_wdt->wdt_base);

	nuc900_wdt->wdt_clock = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(nuc900_wdt->wdt_clock)) {
		dev_err(&pdev->dev, "failed to find watchdog clock source\n");
		return PTR_ERR(nuc900_wdt->wdt_clock);
	}

	clk_enable(nuc900_wdt->wdt_clock);

	setup_timer(&nuc900_wdt->timer, nuc900_wdt_timer_ping, 0);

	ret = misc_register(&nuc900wdt_miscdev);
	if (ret) {
		dev_err(&pdev->dev, "err register miscdev on minor=%d (%d)\n",
			WATCHDOG_MINOR, ret);
		goto err_clk;
	}

	return 0;

err_clk:
	clk_disable(nuc900_wdt->wdt_clock);
	return ret;
}

static int nuc900wdt_remove(struct platform_device *pdev)
{
	misc_deregister(&nuc900wdt_miscdev);

	clk_disable(nuc900_wdt->wdt_clock);

	return 0;
}

static struct platform_driver nuc900wdt_driver = {
	.probe		= nuc900wdt_probe,
	.remove		= nuc900wdt_remove,
	.driver		= {
		.name	= "nuc900-wdt",
	},
};

module_platform_driver(nuc900wdt_driver);

MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
MODULE_DESCRIPTION("Watchdog driver for NUC900");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:nuc900-wdt");
indow, from
    Alexey Kodanev.

 9) Missing kmemdup() failure check in ipv6 segment routing code, from
    Eric Dumazet.

10) Don't execute unix_bind() under the bindlock, otherwise we deadlock
    with splice. From WANG Cong.

11) ip6_tnl_parse_tlv_enc_lim() potentially reallocates the skb buffer,
    therefore callers must reload cached header pointers into that skb.
    Fix from Eric Dumazet.

12) Fix various bugs in legacy IRQ fallback handling in alx driver, from
    Tobias Regnery.

13) Do not allow lwtunnel drivers to be unloaded while they are
    referenced by active instances, from Robert Shearman.

14) Fix truncated PHY LED trigger names, from Geert Uytterhoeven.

15) Fix a few regressions from virtio_net XDP support, from John
    Fastabend and Jakub Kicinski.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (102 commits)
  ISDN: eicon: silence misleading array-bounds warning
  net: phy: micrel: add support for KSZ8795
  gtp: fix cross netns recv on gtp socket
  gtp: clear DF bit on GTP packet tx
  gtp: add genl family modules alias
  tcp: don't annotate mark on control socket from tcp_v6_send_response()
  ravb: unmap descriptors when freeing rings
  virtio_net: reject XDP programs using header adjustment
  virtio_net: use dev_kfree_skb for small buffer XDP receive
  r8152: check rx after napi is enabled
  r8152: re-schedule napi for tx
  r8152: avoid start_xmit to schedule napi when napi is disabled
  r8152: avoid start_xmit to call napi_schedule during autosuspend
  net: dsa: Bring back device detaching in dsa_slave_suspend()
  net: phy: leds: Fix truncated LED trigger names
  net: phy: leds: Break dependency of phy.h on phy_led_triggers.h
  net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash
  net-next: ethernet: mediatek: change the compatible string
  Documentation: devicetree: change the mediatek ethernet compatible string
  bnxt_en: Fix RTNL lock usage on bnxt_get_port_module_status().
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>Diffstat</a> (limited to 'fs/xfs/libxfs/xfs_dir2_block.c')</div><table summary='diffstat' class='diffstat'>