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![Uwe Kleine-König](/assets/img/avatar_default.png)
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230303213716.2123717-31-u.kleine-koenig@pengutronix.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
541 lines
13 KiB
C
541 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
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* integrated watchdog.
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*
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* (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
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*
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* Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
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* provide warranty for any of this software. This material is
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* provided "AS-IS" and at no charge.
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*/
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/*
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* Includes, defines, variables, module parameters, ...
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/* Includes */
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#include <linux/module.h> /* For module specific items */
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#include <linux/moduleparam.h> /* For new moduleparam's */
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#include <linux/types.h> /* For standard types (like size_t) */
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#include <linux/errno.h> /* For the -ENODEV/... values */
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#include <linux/kernel.h> /* For printk/... */
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#include <linux/miscdevice.h> /* For struct miscdevice */
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#include <linux/watchdog.h> /* For the watchdog specific items */
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#include <linux/init.h> /* For __init/__exit/... */
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#include <linux/fs.h> /* For file operations */
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#include <linux/platform_device.h> /* For platform_driver framework */
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#include <linux/ioport.h> /* For io-port access */
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#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
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#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
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#include <linux/io.h> /* For inb/outb/... */
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/* Module and version information */
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#define DRV_NAME "sch311x_wdt"
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/* Runtime registers */
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#define GP60 0x47
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#define WDT_TIME_OUT 0x65
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#define WDT_VAL 0x66
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#define WDT_CFG 0x67
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#define WDT_CTRL 0x68
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/* internal variables */
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static unsigned long sch311x_wdt_is_open;
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static char sch311x_wdt_expect_close;
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static struct platform_device *sch311x_wdt_pdev;
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static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
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static struct { /* The devices private data */
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/* the Runtime Register base address */
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unsigned short runtime_reg;
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/* The card's boot status */
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int boot_status;
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/* the lock for io operations */
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spinlock_t io_lock;
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} sch311x_wdt_data;
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/* Module load parameters */
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static unsigned short force_id;
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module_param(force_id, ushort, 0);
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MODULE_PARM_DESC(force_id, "Override the detected device ID");
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#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
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static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
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module_param(timeout, int, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in seconds. 1<= timeout <=15300, default="
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__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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/*
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* Super-IO functions
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*/
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static inline void sch311x_sio_enter(int sio_config_port)
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{
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outb(0x55, sio_config_port);
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}
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static inline void sch311x_sio_exit(int sio_config_port)
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{
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outb(0xaa, sio_config_port);
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}
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static inline int sch311x_sio_inb(int sio_config_port, int reg)
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{
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outb(reg, sio_config_port);
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return inb(sio_config_port + 1);
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}
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static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
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{
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outb(reg, sio_config_port);
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outb(val, sio_config_port + 1);
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}
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/*
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* Watchdog Operations
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*/
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static void sch311x_wdt_set_timeout(int t)
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{
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unsigned char timeout_unit = 0x80;
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/* When new timeout is bigger then 255 seconds, we will use minutes */
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if (t > 255) {
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timeout_unit = 0;
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t /= 60;
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}
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/* -- Watchdog Timeout --
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* Bit 0-6 (Reserved)
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* Bit 7 WDT Time-out Value Units Select
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* (0 = Minutes, 1 = Seconds)
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*/
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outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
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/* -- Watchdog Timer Time-out Value --
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* Bit 0-7 Binary coded units (0=Disabled, 1..255)
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*/
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outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
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}
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static void sch311x_wdt_start(void)
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{
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unsigned char t;
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spin_lock(&sch311x_wdt_data.io_lock);
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/* set watchdog's timeout */
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sch311x_wdt_set_timeout(timeout);
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/* enable the watchdog */
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/* -- General Purpose I/O Bit 6.0 --
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* Bit 0, In/Out: 0 = Output, 1 = Input
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* Bit 1, Polarity: 0 = No Invert, 1 = Invert
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* Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
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* 10 = Either Edge Triggered Intr.4
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* Bit 4-6 (Reserved)
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* Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
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*/
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t = inb(sch311x_wdt_data.runtime_reg + GP60);
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outb((t & ~0x0d) | 0x0c, sch311x_wdt_data.runtime_reg + GP60);
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spin_unlock(&sch311x_wdt_data.io_lock);
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}
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static void sch311x_wdt_stop(void)
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{
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unsigned char t;
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spin_lock(&sch311x_wdt_data.io_lock);
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/* stop the watchdog */
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t = inb(sch311x_wdt_data.runtime_reg + GP60);
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outb((t & ~0x0d) | 0x01, sch311x_wdt_data.runtime_reg + GP60);
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/* disable timeout by setting it to 0 */
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sch311x_wdt_set_timeout(0);
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spin_unlock(&sch311x_wdt_data.io_lock);
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}
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static void sch311x_wdt_keepalive(void)
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{
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spin_lock(&sch311x_wdt_data.io_lock);
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sch311x_wdt_set_timeout(timeout);
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spin_unlock(&sch311x_wdt_data.io_lock);
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}
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static int sch311x_wdt_set_heartbeat(int t)
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{
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if (t < 1 || t > (255*60))
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return -EINVAL;
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/* When new timeout is bigger then 255 seconds,
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* we will round up to minutes (with a max of 255) */
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if (t > 255)
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t = (((t - 1) / 60) + 1) * 60;
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timeout = t;
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return 0;
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}
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static void sch311x_wdt_get_status(int *status)
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{
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unsigned char new_status;
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*status = 0;
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spin_lock(&sch311x_wdt_data.io_lock);
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/* -- Watchdog timer control --
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* Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
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* Bit 1 Reserved
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* Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
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* Bit 3 P20 Force Timeout enabled:
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* 0 = P20 activity does not generate the WD timeout event
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* 1 = P20 Allows rising edge of P20, from the keyboard
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* controller, to force the WD timeout event.
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* Bit 4-7 Reserved
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*/
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new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
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if (new_status & 0x01)
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*status |= WDIOF_CARDRESET;
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spin_unlock(&sch311x_wdt_data.io_lock);
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}
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/*
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* /dev/watchdog handling
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*/
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static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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if (count) {
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if (!nowayout) {
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size_t i;
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sch311x_wdt_expect_close = 0;
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for (i = 0; i != count; i++) {
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char c;
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if (get_user(c, buf + i))
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return -EFAULT;
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if (c == 'V')
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sch311x_wdt_expect_close = 42;
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}
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}
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sch311x_wdt_keepalive();
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}
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return count;
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}
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static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int status;
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int new_timeout;
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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING |
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WDIOF_SETTIMEOUT |
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WDIOF_MAGICCLOSE,
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.firmware_version = 1,
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.identity = DRV_NAME,
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &ident, sizeof(ident)))
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return -EFAULT;
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break;
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case WDIOC_GETSTATUS:
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{
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sch311x_wdt_get_status(&status);
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return put_user(status, p);
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}
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case WDIOC_GETBOOTSTATUS:
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return put_user(sch311x_wdt_data.boot_status, p);
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case WDIOC_SETOPTIONS:
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{
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int options, retval = -EINVAL;
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if (get_user(options, p))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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sch311x_wdt_stop();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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sch311x_wdt_start();
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retval = 0;
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}
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return retval;
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}
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case WDIOC_KEEPALIVE:
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sch311x_wdt_keepalive();
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break;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_timeout, p))
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return -EFAULT;
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if (sch311x_wdt_set_heartbeat(new_timeout))
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return -EINVAL;
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sch311x_wdt_keepalive();
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fallthrough;
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case WDIOC_GETTIMEOUT:
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return put_user(timeout, p);
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default:
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return -ENOTTY;
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}
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return 0;
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}
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static int sch311x_wdt_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, &sch311x_wdt_is_open))
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return -EBUSY;
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/*
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* Activate
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*/
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sch311x_wdt_start();
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return stream_open(inode, file);
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}
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static int sch311x_wdt_close(struct inode *inode, struct file *file)
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{
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if (sch311x_wdt_expect_close == 42) {
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sch311x_wdt_stop();
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} else {
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pr_crit("Unexpected close, not stopping watchdog!\n");
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sch311x_wdt_keepalive();
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}
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clear_bit(0, &sch311x_wdt_is_open);
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sch311x_wdt_expect_close = 0;
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return 0;
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}
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/*
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* Kernel Interfaces
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*/
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static const struct file_operations sch311x_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = sch311x_wdt_write,
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.unlocked_ioctl = sch311x_wdt_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = sch311x_wdt_open,
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.release = sch311x_wdt_close,
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};
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static struct miscdevice sch311x_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &sch311x_wdt_fops,
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};
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/*
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* Init & exit routines
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*/
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static int sch311x_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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int err;
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spin_lock_init(&sch311x_wdt_data.io_lock);
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if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
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dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
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sch311x_wdt_data.runtime_reg + GP60,
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sch311x_wdt_data.runtime_reg + GP60);
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err = -EBUSY;
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goto exit;
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}
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if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
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DRV_NAME)) {
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dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
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sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
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sch311x_wdt_data.runtime_reg + WDT_CTRL);
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err = -EBUSY;
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goto exit_release_region;
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}
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/* Make sure that the watchdog is not running */
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sch311x_wdt_stop();
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/* Disable keyboard and mouse interaction and interrupt */
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/* -- Watchdog timer configuration --
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* Bit 0 Reserved
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* Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
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* Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
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* Bit 3 Reserved
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* Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
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* 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
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*/
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outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
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/* Check that the heartbeat value is within it's range ;
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* if not reset to the default */
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if (sch311x_wdt_set_heartbeat(timeout)) {
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sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
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dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
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timeout);
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}
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/* Get status at boot */
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sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
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sch311x_wdt_miscdev.parent = dev;
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err = misc_register(&sch311x_wdt_miscdev);
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if (err != 0) {
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dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
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WATCHDOG_MINOR, err);
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goto exit_release_region2;
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}
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dev_info(dev,
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"SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
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timeout, nowayout);
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return 0;
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exit_release_region2:
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release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
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exit_release_region:
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release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
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sch311x_wdt_data.runtime_reg = 0;
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exit:
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return err;
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}
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static void sch311x_wdt_remove(struct platform_device *pdev)
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{
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/* Stop the timer before we leave */
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if (!nowayout)
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sch311x_wdt_stop();
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/* Deregister */
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misc_deregister(&sch311x_wdt_miscdev);
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release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
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release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
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sch311x_wdt_data.runtime_reg = 0;
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}
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static void sch311x_wdt_shutdown(struct platform_device *dev)
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{
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/* Turn the WDT off if we have a soft shutdown */
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sch311x_wdt_stop();
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}
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|
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static struct platform_driver sch311x_wdt_driver = {
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.probe = sch311x_wdt_probe,
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.remove_new = sch311x_wdt_remove,
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.shutdown = sch311x_wdt_shutdown,
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.driver = {
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.name = DRV_NAME,
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},
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};
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static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
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{
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int err = 0, reg;
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unsigned short base_addr;
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unsigned char dev_id;
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sch311x_sio_enter(sio_config_port);
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|
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/* Check device ID. We currently know about:
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* SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
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reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
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if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
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err = -ENODEV;
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goto exit;
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}
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dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
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/* Select logical device A (runtime registers) */
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sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
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/* Check if Logical Device Register is currently active */
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if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
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pr_info("Seems that LDN 0x0a is not active...\n");
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/* Get the base address of the runtime registers */
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base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
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sch311x_sio_inb(sio_config_port, 0x61);
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|
if (!base_addr) {
|
|
pr_err("Base address not set\n");
|
|
err = -ENODEV;
|
|
goto exit;
|
|
}
|
|
*addr = base_addr;
|
|
|
|
pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
|
|
|
|
exit:
|
|
sch311x_sio_exit(sio_config_port);
|
|
return err;
|
|
}
|
|
|
|
static int __init sch311x_wdt_init(void)
|
|
{
|
|
int err, i, found = 0;
|
|
unsigned short addr = 0;
|
|
|
|
for (i = 0; !found && sch311x_ioports[i]; i++)
|
|
if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
|
|
found++;
|
|
|
|
if (!found)
|
|
return -ENODEV;
|
|
|
|
sch311x_wdt_data.runtime_reg = addr;
|
|
|
|
err = platform_driver_register(&sch311x_wdt_driver);
|
|
if (err)
|
|
return err;
|
|
|
|
sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
|
|
NULL, 0);
|
|
|
|
if (IS_ERR(sch311x_wdt_pdev)) {
|
|
err = PTR_ERR(sch311x_wdt_pdev);
|
|
goto unreg_platform_driver;
|
|
}
|
|
|
|
return 0;
|
|
|
|
unreg_platform_driver:
|
|
platform_driver_unregister(&sch311x_wdt_driver);
|
|
return err;
|
|
}
|
|
|
|
static void __exit sch311x_wdt_exit(void)
|
|
{
|
|
platform_device_unregister(sch311x_wdt_pdev);
|
|
platform_driver_unregister(&sch311x_wdt_driver);
|
|
}
|
|
|
|
module_init(sch311x_wdt_init);
|
|
module_exit(sch311x_wdt_exit);
|
|
|
|
MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
|
|
MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
|
|
MODULE_LICENSE("GPL");
|