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257 lines
6.3 KiB
257 lines
6.3 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Watchdog driver for the UniPhier watchdog timer |
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* |
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* (c) Copyright 2014 Panasonic Corporation |
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* (c) Copyright 2016 Socionext Inc. |
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* All rights reserved. |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/mfd/syscon.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/regmap.h> |
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#include <linux/watchdog.h> |
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/* WDT timer setting register */ |
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#define WDTTIMSET 0x3004 |
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#define WDTTIMSET_PERIOD_MASK (0xf << 0) |
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#define WDTTIMSET_PERIOD_1_SEC (0x3 << 0) |
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/* WDT reset selection register */ |
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#define WDTRSTSEL 0x3008 |
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#define WDTRSTSEL_RSTSEL_MASK (0x3 << 0) |
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#define WDTRSTSEL_RSTSEL_BOTH (0x0 << 0) |
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#define WDTRSTSEL_RSTSEL_IRQ_ONLY (0x2 << 0) |
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/* WDT control register */ |
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#define WDTCTRL 0x300c |
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#define WDTCTRL_STATUS BIT(8) |
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#define WDTCTRL_CLEAR BIT(1) |
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#define WDTCTRL_ENABLE BIT(0) |
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#define SEC_TO_WDTTIMSET_PRD(sec) \ |
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(ilog2(sec) + WDTTIMSET_PERIOD_1_SEC) |
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#define WDTST_TIMEOUT 1000 /* usec */ |
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#define WDT_DEFAULT_TIMEOUT 64 /* Default is 64 seconds */ |
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#define WDT_PERIOD_MIN 1 |
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#define WDT_PERIOD_MAX 128 |
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static unsigned int timeout = 0; |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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struct uniphier_wdt_dev { |
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struct watchdog_device wdt_dev; |
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struct regmap *regmap; |
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}; |
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/* |
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* UniPhier Watchdog operations |
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*/ |
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static int uniphier_watchdog_ping(struct watchdog_device *w) |
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{ |
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struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); |
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unsigned int val; |
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int ret; |
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/* Clear counter */ |
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ret = regmap_write_bits(wdev->regmap, WDTCTRL, |
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WDTCTRL_CLEAR, WDTCTRL_CLEAR); |
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if (!ret) |
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/* |
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* As SoC specification, after clear counter, |
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* it needs to wait until counter status is 1. |
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*/ |
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ret = regmap_read_poll_timeout(wdev->regmap, WDTCTRL, val, |
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(val & WDTCTRL_STATUS), |
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0, WDTST_TIMEOUT); |
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return ret; |
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} |
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static int __uniphier_watchdog_start(struct regmap *regmap, unsigned int sec) |
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{ |
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unsigned int val; |
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int ret; |
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ret = regmap_read_poll_timeout(regmap, WDTCTRL, val, |
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!(val & WDTCTRL_STATUS), |
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0, WDTST_TIMEOUT); |
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if (ret) |
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return ret; |
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/* Setup period */ |
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ret = regmap_write(regmap, WDTTIMSET, |
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SEC_TO_WDTTIMSET_PRD(sec)); |
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if (ret) |
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return ret; |
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/* Enable and clear watchdog */ |
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ret = regmap_write(regmap, WDTCTRL, WDTCTRL_ENABLE | WDTCTRL_CLEAR); |
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if (!ret) |
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/* |
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* As SoC specification, after clear counter, |
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* it needs to wait until counter status is 1. |
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*/ |
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ret = regmap_read_poll_timeout(regmap, WDTCTRL, val, |
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(val & WDTCTRL_STATUS), |
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0, WDTST_TIMEOUT); |
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return ret; |
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} |
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static int __uniphier_watchdog_stop(struct regmap *regmap) |
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{ |
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/* Disable and stop watchdog */ |
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return regmap_write_bits(regmap, WDTCTRL, WDTCTRL_ENABLE, 0); |
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} |
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static int __uniphier_watchdog_restart(struct regmap *regmap, unsigned int sec) |
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{ |
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int ret; |
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ret = __uniphier_watchdog_stop(regmap); |
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if (ret) |
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return ret; |
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return __uniphier_watchdog_start(regmap, sec); |
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} |
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static int uniphier_watchdog_start(struct watchdog_device *w) |
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{ |
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struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); |
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unsigned int tmp_timeout; |
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tmp_timeout = roundup_pow_of_two(w->timeout); |
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return __uniphier_watchdog_start(wdev->regmap, tmp_timeout); |
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} |
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static int uniphier_watchdog_stop(struct watchdog_device *w) |
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{ |
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struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); |
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return __uniphier_watchdog_stop(wdev->regmap); |
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} |
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static int uniphier_watchdog_set_timeout(struct watchdog_device *w, |
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unsigned int t) |
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{ |
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struct uniphier_wdt_dev *wdev = watchdog_get_drvdata(w); |
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unsigned int tmp_timeout; |
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int ret; |
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tmp_timeout = roundup_pow_of_two(t); |
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if (tmp_timeout == w->timeout) |
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return 0; |
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if (watchdog_active(w)) { |
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ret = __uniphier_watchdog_restart(wdev->regmap, tmp_timeout); |
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if (ret) |
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return ret; |
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} |
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w->timeout = tmp_timeout; |
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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 watchdog_info uniphier_wdt_info = { |
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.identity = "uniphier-wdt", |
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.options = WDIOF_SETTIMEOUT | |
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WDIOF_KEEPALIVEPING | |
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WDIOF_MAGICCLOSE | |
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WDIOF_OVERHEAT, |
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}; |
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static const struct watchdog_ops uniphier_wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = uniphier_watchdog_start, |
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.stop = uniphier_watchdog_stop, |
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.ping = uniphier_watchdog_ping, |
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.set_timeout = uniphier_watchdog_set_timeout, |
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}; |
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static int uniphier_wdt_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct uniphier_wdt_dev *wdev; |
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struct regmap *regmap; |
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struct device_node *parent; |
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int ret; |
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wdev = devm_kzalloc(dev, sizeof(*wdev), GFP_KERNEL); |
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if (!wdev) |
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return -ENOMEM; |
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parent = of_get_parent(dev->of_node); /* parent should be syscon node */ |
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regmap = syscon_node_to_regmap(parent); |
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of_node_put(parent); |
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if (IS_ERR(regmap)) |
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return PTR_ERR(regmap); |
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wdev->regmap = regmap; |
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wdev->wdt_dev.info = &uniphier_wdt_info; |
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wdev->wdt_dev.ops = &uniphier_wdt_ops; |
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wdev->wdt_dev.max_timeout = WDT_PERIOD_MAX; |
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wdev->wdt_dev.min_timeout = WDT_PERIOD_MIN; |
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wdev->wdt_dev.timeout = WDT_DEFAULT_TIMEOUT; |
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wdev->wdt_dev.parent = dev; |
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watchdog_init_timeout(&wdev->wdt_dev, timeout, dev); |
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watchdog_set_nowayout(&wdev->wdt_dev, nowayout); |
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watchdog_stop_on_reboot(&wdev->wdt_dev); |
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watchdog_set_drvdata(&wdev->wdt_dev, wdev); |
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uniphier_watchdog_stop(&wdev->wdt_dev); |
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ret = regmap_write(wdev->regmap, WDTRSTSEL, WDTRSTSEL_RSTSEL_BOTH); |
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if (ret) |
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return ret; |
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ret = devm_watchdog_register_device(dev, &wdev->wdt_dev); |
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if (ret) |
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return ret; |
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dev_info(dev, "watchdog driver (timeout=%d sec, nowayout=%d)\n", |
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wdev->wdt_dev.timeout, nowayout); |
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return 0; |
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} |
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static const struct of_device_id uniphier_wdt_dt_ids[] = { |
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{ .compatible = "socionext,uniphier-wdt" }, |
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{ /* sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, uniphier_wdt_dt_ids); |
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static struct platform_driver uniphier_wdt_driver = { |
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.probe = uniphier_wdt_probe, |
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.driver = { |
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.name = "uniphier-wdt", |
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.of_match_table = uniphier_wdt_dt_ids, |
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}, |
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}; |
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module_platform_driver(uniphier_wdt_driver); |
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module_param(timeout, uint, 0000); |
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MODULE_PARM_DESC(timeout, |
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"Watchdog timeout seconds in power of 2. (0 < timeout < 128, default=" |
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__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")"); |
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module_param(nowayout, bool, 0000); |
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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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MODULE_AUTHOR("Keiji Hayashibara <[email protected]>"); |
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MODULE_DESCRIPTION("UniPhier Watchdog Device Driver"); |
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MODULE_LICENSE("GPL v2");
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