| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Harini Katakam | 1235 | 92.30% | 1 | 7.14% |
| Guenter Roeck | 50 | 3.74% | 2 | 14.29% |
| Shubhrajyoti Datta | 24 | 1.79% | 1 | 7.14% |
| Damien Riegel | 11 | 0.82% | 1 | 7.14% |
| Krzysztof Kozlowski | 5 | 0.37% | 1 | 7.14% |
| Wolfram Sang | 4 | 0.30% | 1 | 7.14% |
| Michal Simek | 3 | 0.22% | 2 | 14.29% |
| Marcus Folkesson | 2 | 0.15% | 1 | 7.14% |
| Bhumika Goyal | 1 | 0.07% | 1 | 7.14% |
| Srinivas Neeli | 1 | 0.07% | 1 | 7.14% |
| Arvind Yadav | 1 | 0.07% | 1 | 7.14% |
| Julia Lawall | 1 | 0.07% | 1 | 7.14% |
| Total | 1338 | 14 |
// SPDX-License-Identifier: GPL-2.0+ /* * Cadence WDT driver - Used by Xilinx Zynq * * Copyright (C) 2010 - 2014 Xilinx, Inc. * */ #include <linux/clk.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/watchdog.h> #define CDNS_WDT_DEFAULT_TIMEOUT 10 /* Supports 1 - 516 sec */ #define CDNS_WDT_MIN_TIMEOUT 1 #define CDNS_WDT_MAX_TIMEOUT 516 /* Restart key */ #define CDNS_WDT_RESTART_KEY 0x00001999 /* Counter register access key */ #define CDNS_WDT_REGISTER_ACCESS_KEY 0x00920000 /* Counter value divisor */ #define CDNS_WDT_COUNTER_VALUE_DIVISOR 0x1000 /* Clock prescaler value and selection */ #define CDNS_WDT_PRESCALE_64 64 #define CDNS_WDT_PRESCALE_512 512 #define CDNS_WDT_PRESCALE_4096 4096 #define CDNS_WDT_PRESCALE_SELECT_64 1 #define CDNS_WDT_PRESCALE_SELECT_512 2 #define CDNS_WDT_PRESCALE_SELECT_4096 3 /* Input clock frequency */ #define CDNS_WDT_CLK_10MHZ 10000000 #define CDNS_WDT_CLK_75MHZ 75000000 /* Counter maximum value */ #define CDNS_WDT_COUNTER_MAX 0xFFF static int wdt_timeout; static int nowayout = WATCHDOG_NOWAYOUT; module_param(wdt_timeout, int, 0644); MODULE_PARM_DESC(wdt_timeout, "Watchdog time in seconds. (default=" __MODULE_STRING(CDNS_WDT_DEFAULT_TIMEOUT) ")"); module_param(nowayout, int, 0644); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); /** * struct cdns_wdt - Watchdog device structure * @regs: baseaddress of device * @rst: reset flag * @clk: struct clk * of a clock source * @prescaler: for saving prescaler value * @ctrl_clksel: counter clock prescaler selection * @io_lock: spinlock for IO register access * @cdns_wdt_device: watchdog device structure * * Structure containing parameters specific to cadence watchdog. */ struct cdns_wdt { void __iomem *regs; bool rst; struct clk *clk; u32 prescaler; u32 ctrl_clksel; spinlock_t io_lock; struct watchdog_device cdns_wdt_device; }; /* Write access to Registers */ static inline void cdns_wdt_writereg(struct cdns_wdt *wdt, u32 offset, u32 val) { writel_relaxed(val, wdt->regs + offset); } /*************************Register Map**************************************/ /* Register Offsets for the WDT */ #define CDNS_WDT_ZMR_OFFSET 0x0 /* Zero Mode Register */ #define CDNS_WDT_CCR_OFFSET 0x4 /* Counter Control Register */ #define CDNS_WDT_RESTART_OFFSET 0x8 /* Restart Register */ #define CDNS_WDT_SR_OFFSET 0xC /* Status Register */ /* * Zero Mode Register - This register controls how the time out is indicated * and also contains the access code to allow writes to the register (0xABC). */ #define CDNS_WDT_ZMR_WDEN_MASK 0x00000001 /* Enable the WDT */ #define CDNS_WDT_ZMR_RSTEN_MASK 0x00000002 /* Enable the reset output */ #define CDNS_WDT_ZMR_IRQEN_MASK 0x00000004 /* Enable IRQ output */ #define CDNS_WDT_ZMR_RSTLEN_16 0x00000030 /* Reset pulse of 16 pclk cycles */ #define CDNS_WDT_ZMR_ZKEY_VAL 0x00ABC000 /* Access key, 0xABC << 12 */ /* * Counter Control register - This register controls how fast the timer runs * and the reset value and also contains the access code to allow writes to * the register. */ #define CDNS_WDT_CCR_CRV_MASK 0x00003FFC /* Counter reset value */ /** * cdns_wdt_stop - Stop the watchdog. * * @wdd: watchdog device * * Read the contents of the ZMR register, clear the WDEN bit * in the register and set the access key for successful write. * * Return: always 0 */ static int cdns_wdt_stop(struct watchdog_device *wdd) { struct cdns_wdt *wdt = watchdog_get_drvdata(wdd); spin_lock(&wdt->io_lock); cdns_wdt_writereg(wdt, CDNS_WDT_ZMR_OFFSET, CDNS_WDT_ZMR_ZKEY_VAL & (~CDNS_WDT_ZMR_WDEN_MASK)); spin_unlock(&wdt->io_lock); return 0; } /** * cdns_wdt_reload - Reload the watchdog timer (i.e. pat the watchdog). * * @wdd: watchdog device * * Write the restart key value (0x00001999) to the restart register. * * Return: always 0 */ static int cdns_wdt_reload(struct watchdog_device *wdd) { struct cdns_wdt *wdt = watchdog_get_drvdata(wdd); spin_lock(&wdt->io_lock); cdns_wdt_writereg(wdt, CDNS_WDT_RESTART_OFFSET, CDNS_WDT_RESTART_KEY); spin_unlock(&wdt->io_lock); return 0; } /** * cdns_wdt_start - Enable and start the watchdog. * * @wdd: watchdog device * * The counter value is calculated according to the formula: * calculated count = (timeout * clock) / prescaler + 1. * The calculated count is divided by 0x1000 to obtain the field value * to write to counter control register. * Clears the contents of prescaler and counter reset value. Sets the * prescaler to 4096 and the calculated count and access key * to write to CCR Register. * Sets the WDT (WDEN bit) and either the Reset signal(RSTEN bit) * or Interrupt signal(IRQEN) with a specified cycles and the access * key to write to ZMR Register. * * Return: always 0 */ static int cdns_wdt_start(struct watchdog_device *wdd) { struct cdns_wdt *wdt = watchdog_get_drvdata(wdd); unsigned int data = 0; unsigned short count; unsigned long clock_f = clk_get_rate(wdt->clk); /* * Counter value divisor to obtain the value of * counter reset to be written to control register. */ count = (wdd->timeout * (clock_f / wdt->prescaler)) / CDNS_WDT_COUNTER_VALUE_DIVISOR + 1; if (count > CDNS_WDT_COUNTER_MAX) count = CDNS_WDT_COUNTER_MAX; spin_lock(&wdt->io_lock); cdns_wdt_writereg(wdt, CDNS_WDT_ZMR_OFFSET, CDNS_WDT_ZMR_ZKEY_VAL); count = (count << 2) & CDNS_WDT_CCR_CRV_MASK; /* Write counter access key first to be able write to register */ data = count | CDNS_WDT_REGISTER_ACCESS_KEY | wdt->ctrl_clksel; cdns_wdt_writereg(wdt, CDNS_WDT_CCR_OFFSET, data); data = CDNS_WDT_ZMR_WDEN_MASK | CDNS_WDT_ZMR_RSTLEN_16 | CDNS_WDT_ZMR_ZKEY_VAL; /* Reset on timeout if specified in device tree. */ if (wdt->rst) { data |= CDNS_WDT_ZMR_RSTEN_MASK; data &= ~CDNS_WDT_ZMR_IRQEN_MASK; } else { data &= ~CDNS_WDT_ZMR_RSTEN_MASK; data |= CDNS_WDT_ZMR_IRQEN_MASK; } cdns_wdt_writereg(wdt, CDNS_WDT_ZMR_OFFSET, data); cdns_wdt_writereg(wdt, CDNS_WDT_RESTART_OFFSET, CDNS_WDT_RESTART_KEY); spin_unlock(&wdt->io_lock); return 0; } /** * cdns_wdt_settimeout - Set a new timeout value for the watchdog device. * * @wdd: watchdog device * @new_time: new timeout value that needs to be set * Return: 0 on success * * Update the watchdog_device timeout with new value which is used when * cdns_wdt_start is called. */ static int cdns_wdt_settimeout(struct watchdog_device *wdd, unsigned int new_time) { wdd->timeout = new_time; return cdns_wdt_start(wdd); } /** * cdns_wdt_irq_handler - Notifies of watchdog timeout. * * @irq: interrupt number * @dev_id: pointer to a platform device structure * Return: IRQ_HANDLED * * The handler is invoked when the watchdog times out and a * reset on timeout has not been enabled. */ static irqreturn_t cdns_wdt_irq_handler(int irq, void *dev_id) { struct platform_device *pdev = dev_id; dev_info(&pdev->dev, "Watchdog timed out. Internal reset not enabled\n"); return IRQ_HANDLED; } /* * Info structure used to indicate the features supported by the device * to the upper layers. This is defined in watchdog.h header file. */ static const struct watchdog_info cdns_wdt_info = { .identity = "cdns_wdt watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; /* Watchdog Core Ops */ static const struct watchdog_ops cdns_wdt_ops = { .owner = THIS_MODULE, .start = cdns_wdt_start, .stop = cdns_wdt_stop, .ping = cdns_wdt_reload, .set_timeout = cdns_wdt_settimeout, }; static void cdns_clk_disable_unprepare(void *data) { clk_disable_unprepare(data); } /************************Platform Operations*****************************/ /** * cdns_wdt_probe - Probe call for the device. * * @pdev: handle to the platform device structure. * Return: 0 on success, negative error otherwise. * * It does all the memory allocation and registration for the device. */ static int cdns_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; int ret, irq; unsigned long clock_f; struct cdns_wdt *wdt; struct watchdog_device *cdns_wdt_device; wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; cdns_wdt_device = &wdt->cdns_wdt_device; cdns_wdt_device->info = &cdns_wdt_info; cdns_wdt_device->ops = &cdns_wdt_ops; cdns_wdt_device->timeout = CDNS_WDT_DEFAULT_TIMEOUT; cdns_wdt_device->min_timeout = CDNS_WDT_MIN_TIMEOUT; cdns_wdt_device->max_timeout = CDNS_WDT_MAX_TIMEOUT; wdt->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(wdt->regs)) return PTR_ERR(wdt->regs); /* Register the interrupt */ wdt->rst = of_property_read_bool(dev->of_node, "reset-on-timeout"); irq = platform_get_irq(pdev, 0); if (!wdt->rst && irq >= 0) { ret = devm_request_irq(dev, irq, cdns_wdt_irq_handler, 0, pdev->name, pdev); if (ret) { dev_err(dev, "cannot register interrupt handler err=%d\n", ret); return ret; } } /* Initialize the members of cdns_wdt structure */ cdns_wdt_device->parent = dev; watchdog_init_timeout(cdns_wdt_device, wdt_timeout, dev); watchdog_set_nowayout(cdns_wdt_device, nowayout); watchdog_stop_on_reboot(cdns_wdt_device); watchdog_set_drvdata(cdns_wdt_device, wdt); wdt->clk = devm_clk_get(dev, NULL); if (IS_ERR(wdt->clk)) return dev_err_probe(dev, PTR_ERR(wdt->clk), "input clock not found\n"); ret = clk_prepare_enable(wdt->clk); if (ret) { dev_err(dev, "unable to enable clock\n"); return ret; } ret = devm_add_action_or_reset(dev, cdns_clk_disable_unprepare, wdt->clk); if (ret) return ret; clock_f = clk_get_rate(wdt->clk); if (clock_f <= CDNS_WDT_CLK_75MHZ) { wdt->prescaler = CDNS_WDT_PRESCALE_512; wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_512; } else { wdt->prescaler = CDNS_WDT_PRESCALE_4096; wdt->ctrl_clksel = CDNS_WDT_PRESCALE_SELECT_4096; } spin_lock_init(&wdt->io_lock); watchdog_stop_on_reboot(cdns_wdt_device); watchdog_stop_on_unregister(cdns_wdt_device); ret = devm_watchdog_register_device(dev, cdns_wdt_device); if (ret) return ret; platform_set_drvdata(pdev, wdt); dev_info(dev, "Xilinx Watchdog Timer with timeout %ds%s\n", cdns_wdt_device->timeout, nowayout ? ", nowayout" : ""); return 0; } /** * cdns_wdt_suspend - Stop the device. * * @dev: handle to the device structure. * Return: 0 always. */ static int __maybe_unused cdns_wdt_suspend(struct device *dev) { struct cdns_wdt *wdt = dev_get_drvdata(dev); if (watchdog_active(&wdt->cdns_wdt_device)) { cdns_wdt_stop(&wdt->cdns_wdt_device); clk_disable_unprepare(wdt->clk); } return 0; } /** * cdns_wdt_resume - Resume the device. * * @dev: handle to the device structure. * Return: 0 on success, errno otherwise. */ static int __maybe_unused cdns_wdt_resume(struct device *dev) { int ret; struct cdns_wdt *wdt = dev_get_drvdata(dev); if (watchdog_active(&wdt->cdns_wdt_device)) { ret = clk_prepare_enable(wdt->clk); if (ret) { dev_err(dev, "unable to enable clock\n"); return ret; } cdns_wdt_start(&wdt->cdns_wdt_device); } return 0; } static SIMPLE_DEV_PM_OPS(cdns_wdt_pm_ops, cdns_wdt_suspend, cdns_wdt_resume); static const struct of_device_id cdns_wdt_of_match[] = { { .compatible = "cdns,wdt-r1p2", }, { /* end of table */ } }; MODULE_DEVICE_TABLE(of, cdns_wdt_of_match); /* Driver Structure */ static struct platform_driver cdns_wdt_driver = { .probe = cdns_wdt_probe, .driver = { .name = "cdns-wdt", .of_match_table = cdns_wdt_of_match, .pm = &cdns_wdt_pm_ops, }, }; module_platform_driver(cdns_wdt_driver); MODULE_AUTHOR("Xilinx, Inc."); MODULE_DESCRIPTION("Watchdog driver for Cadence WDT"); MODULE_LICENSE("GPL");
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