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171 lines
4.0 KiB
171 lines
4.0 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Watchdog driver for the MEN z069 IP-Core |
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* |
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* Copyright (C) 2018 Johannes Thumshirn <[email protected]> |
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*/ |
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#include <linux/io.h> |
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#include <linux/kernel.h> |
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#include <linux/mcb.h> |
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#include <linux/module.h> |
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#include <linux/watchdog.h> |
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struct men_z069_drv { |
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struct watchdog_device wdt; |
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void __iomem *base; |
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struct resource *mem; |
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}; |
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#define MEN_Z069_WTR 0x10 |
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#define MEN_Z069_WTR_WDEN BIT(15) |
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#define MEN_Z069_WTR_WDET_MASK 0x7fff |
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#define MEN_Z069_WVR 0x14 |
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#define MEN_Z069_TIMER_FREQ 500 /* 500 Hz */ |
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#define MEN_Z069_WDT_COUNTER_MIN 1 |
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#define MEN_Z069_WDT_COUNTER_MAX 0x7fff |
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#define MEN_Z069_DEFAULT_TIMEOUT 30 |
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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 int men_z069_wdt_start(struct watchdog_device *wdt) |
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{ |
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struct men_z069_drv *drv = watchdog_get_drvdata(wdt); |
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u16 val; |
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val = readw(drv->base + MEN_Z069_WTR); |
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val |= MEN_Z069_WTR_WDEN; |
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writew(val, drv->base + MEN_Z069_WTR); |
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return 0; |
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} |
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static int men_z069_wdt_stop(struct watchdog_device *wdt) |
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{ |
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struct men_z069_drv *drv = watchdog_get_drvdata(wdt); |
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u16 val; |
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val = readw(drv->base + MEN_Z069_WTR); |
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val &= ~MEN_Z069_WTR_WDEN; |
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writew(val, drv->base + MEN_Z069_WTR); |
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return 0; |
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} |
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static int men_z069_wdt_ping(struct watchdog_device *wdt) |
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{ |
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struct men_z069_drv *drv = watchdog_get_drvdata(wdt); |
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u16 val; |
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/* The watchdog trigger value toggles between 0x5555 and 0xaaaa */ |
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val = readw(drv->base + MEN_Z069_WVR); |
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val ^= 0xffff; |
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writew(val, drv->base + MEN_Z069_WVR); |
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return 0; |
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} |
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static int men_z069_wdt_set_timeout(struct watchdog_device *wdt, |
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unsigned int timeout) |
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{ |
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struct men_z069_drv *drv = watchdog_get_drvdata(wdt); |
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u16 reg, val, ena; |
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wdt->timeout = timeout; |
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val = timeout * MEN_Z069_TIMER_FREQ; |
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reg = readw(drv->base + MEN_Z069_WVR); |
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ena = reg & MEN_Z069_WTR_WDEN; |
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reg = ena | val; |
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writew(reg, drv->base + MEN_Z069_WTR); |
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return 0; |
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} |
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static const struct watchdog_info men_z069_info = { |
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
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.identity = "MEN z069 Watchdog", |
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}; |
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static const struct watchdog_ops men_z069_ops = { |
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.owner = THIS_MODULE, |
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.start = men_z069_wdt_start, |
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.stop = men_z069_wdt_stop, |
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.ping = men_z069_wdt_ping, |
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.set_timeout = men_z069_wdt_set_timeout, |
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}; |
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static struct watchdog_device men_z069_wdt = { |
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.info = &men_z069_info, |
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.ops = &men_z069_ops, |
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.timeout = MEN_Z069_DEFAULT_TIMEOUT, |
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.min_timeout = 1, |
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.max_timeout = MEN_Z069_WDT_COUNTER_MAX / MEN_Z069_TIMER_FREQ, |
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}; |
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static int men_z069_probe(struct mcb_device *dev, |
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const struct mcb_device_id *id) |
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{ |
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struct men_z069_drv *drv; |
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struct resource *mem; |
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drv = devm_kzalloc(&dev->dev, sizeof(struct men_z069_drv), GFP_KERNEL); |
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if (!drv) |
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return -ENOMEM; |
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mem = mcb_request_mem(dev, "z069-wdt"); |
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if (IS_ERR(mem)) |
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return PTR_ERR(mem); |
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drv->base = devm_ioremap(&dev->dev, mem->start, resource_size(mem)); |
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if (drv->base == NULL) |
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goto release_mem; |
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drv->mem = mem; |
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drv->wdt = men_z069_wdt; |
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watchdog_init_timeout(&drv->wdt, 0, &dev->dev); |
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watchdog_set_nowayout(&drv->wdt, nowayout); |
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watchdog_set_drvdata(&drv->wdt, drv); |
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drv->wdt.parent = &dev->dev; |
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mcb_set_drvdata(dev, drv); |
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return watchdog_register_device(&men_z069_wdt); |
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release_mem: |
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mcb_release_mem(mem); |
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return -ENOMEM; |
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} |
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static void men_z069_remove(struct mcb_device *dev) |
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{ |
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struct men_z069_drv *drv = mcb_get_drvdata(dev); |
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watchdog_unregister_device(&drv->wdt); |
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mcb_release_mem(drv->mem); |
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} |
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static const struct mcb_device_id men_z069_ids[] = { |
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{ .device = 0x45 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(mcb, men_z069_ids); |
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static struct mcb_driver men_z069_driver = { |
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.driver = { |
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.name = "z069-wdt", |
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.owner = THIS_MODULE, |
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}, |
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.probe = men_z069_probe, |
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.remove = men_z069_remove, |
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.id_table = men_z069_ids, |
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}; |
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module_mcb_driver(men_z069_driver); |
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MODULE_AUTHOR("Johannes Thumshirn <[email protected]>"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("mcb:16z069"); |
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MODULE_IMPORT_NS(MCB);
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