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142 lines
3.5 KiB
142 lines
3.5 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Watchdog timer driver for the WinSystems EBC-C384 |
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* Copyright (C) 2016 William Breathitt Gray |
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*/ |
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#include <linux/device.h> |
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#include <linux/dmi.h> |
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#include <linux/errno.h> |
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#include <linux/io.h> |
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#include <linux/ioport.h> |
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#include <linux/isa.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/types.h> |
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#include <linux/watchdog.h> |
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#define MODULE_NAME "ebc-c384_wdt" |
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#define WATCHDOG_TIMEOUT 60 |
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/* |
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* The timeout value in minutes must fit in a single byte when sent to the |
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* watchdog timer; the maximum timeout possible is 15300 (255 * 60) seconds. |
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*/ |
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#define WATCHDOG_MAX_TIMEOUT 15300 |
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#define BASE_ADDR 0x564 |
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#define ADDR_EXTENT 5 |
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#define CFG_ADDR (BASE_ADDR + 1) |
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#define PET_ADDR (BASE_ADDR + 2) |
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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, "Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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static unsigned timeout; |
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module_param(timeout, uint, 0); |
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MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=" |
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__MODULE_STRING(WATCHDOG_TIMEOUT) ")"); |
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static int ebc_c384_wdt_start(struct watchdog_device *wdev) |
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{ |
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unsigned t = wdev->timeout; |
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/* resolution is in minutes for timeouts greater than 255 seconds */ |
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if (t > 255) |
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t = DIV_ROUND_UP(t, 60); |
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outb(t, PET_ADDR); |
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return 0; |
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} |
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static int ebc_c384_wdt_stop(struct watchdog_device *wdev) |
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{ |
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outb(0x00, PET_ADDR); |
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return 0; |
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} |
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static int ebc_c384_wdt_set_timeout(struct watchdog_device *wdev, unsigned t) |
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{ |
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/* resolution is in minutes for timeouts greater than 255 seconds */ |
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if (t > 255) { |
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/* round second resolution up to minute granularity */ |
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wdev->timeout = roundup(t, 60); |
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/* set watchdog timer for minutes */ |
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outb(0x00, CFG_ADDR); |
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} else { |
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wdev->timeout = t; |
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/* set watchdog timer for seconds */ |
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outb(0x80, CFG_ADDR); |
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} |
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return 0; |
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} |
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static const struct watchdog_ops ebc_c384_wdt_ops = { |
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.start = ebc_c384_wdt_start, |
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.stop = ebc_c384_wdt_stop, |
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.set_timeout = ebc_c384_wdt_set_timeout |
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}; |
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static const struct watchdog_info ebc_c384_wdt_info = { |
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.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT, |
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.identity = MODULE_NAME |
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}; |
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static int ebc_c384_wdt_probe(struct device *dev, unsigned int id) |
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{ |
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struct watchdog_device *wdd; |
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if (!devm_request_region(dev, BASE_ADDR, ADDR_EXTENT, dev_name(dev))) { |
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dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", |
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BASE_ADDR, BASE_ADDR + ADDR_EXTENT); |
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return -EBUSY; |
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} |
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wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); |
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if (!wdd) |
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return -ENOMEM; |
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wdd->info = &ebc_c384_wdt_info; |
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wdd->ops = &ebc_c384_wdt_ops; |
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wdd->timeout = WATCHDOG_TIMEOUT; |
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wdd->min_timeout = 1; |
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wdd->max_timeout = WATCHDOG_MAX_TIMEOUT; |
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watchdog_set_nowayout(wdd, nowayout); |
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watchdog_init_timeout(wdd, timeout, dev); |
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return devm_watchdog_register_device(dev, wdd); |
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} |
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static struct isa_driver ebc_c384_wdt_driver = { |
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.probe = ebc_c384_wdt_probe, |
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.driver = { |
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.name = MODULE_NAME |
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}, |
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}; |
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static int __init ebc_c384_wdt_init(void) |
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{ |
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if (!dmi_match(DMI_BOARD_NAME, "EBC-C384 SBC")) |
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return -ENODEV; |
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return isa_register_driver(&ebc_c384_wdt_driver, 1); |
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} |
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static void __exit ebc_c384_wdt_exit(void) |
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{ |
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isa_unregister_driver(&ebc_c384_wdt_driver); |
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} |
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module_init(ebc_c384_wdt_init); |
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module_exit(ebc_c384_wdt_exit); |
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MODULE_AUTHOR("William Breathitt Gray <[email protected]>"); |
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MODULE_DESCRIPTION("WinSystems EBC-C384 watchdog timer driver"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("isa:" MODULE_NAME);
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