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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/watchdog/sama5d4_wdt.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/watchdog/sama5d4_wdt.c')
-rw-r--r-- | drivers/watchdog/sama5d4_wdt.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c new file mode 100644 index 000000000..e5d11d6a2 --- /dev/null +++ b/drivers/watchdog/sama5d4_wdt.c @@ -0,0 +1,382 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Atmel SAMA5D4 Watchdog Timer + * + * Copyright (C) 2015-2019 Microchip Technology Inc. and its subsidiaries + */ + +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/watchdog.h> + +#include "at91sam9_wdt.h" + +/* minimum and maximum watchdog timeout, in seconds */ +#define MIN_WDT_TIMEOUT 1 +#define MAX_WDT_TIMEOUT 16 +#define WDT_DEFAULT_TIMEOUT MAX_WDT_TIMEOUT + +#define WDT_SEC2TICKS(s) ((s) ? (((s) << 8) - 1) : 0) + +struct sama5d4_wdt { + struct watchdog_device wdd; + void __iomem *reg_base; + u32 mr; + u32 ir; + unsigned long last_ping; + bool need_irq; + bool sam9x60_support; +}; + +static int wdt_timeout; +static bool nowayout = WATCHDOG_NOWAYOUT; + +module_param(wdt_timeout, int, 0); +MODULE_PARM_DESC(wdt_timeout, + "Watchdog timeout in seconds. (default = " + __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +#define wdt_enabled (!(wdt->mr & AT91_WDT_WDDIS)) + +#define wdt_read(wdt, field) \ + readl_relaxed((wdt)->reg_base + (field)) + +/* 4 slow clock periods is 4/32768 = 122.07µs*/ +#define WDT_DELAY usecs_to_jiffies(123) + +static void wdt_write(struct sama5d4_wdt *wdt, u32 field, u32 val) +{ + /* + * WDT_CR and WDT_MR must not be modified within three slow clock + * periods following a restart of the watchdog performed by a write + * access in WDT_CR. + */ + while (time_before(jiffies, wdt->last_ping + WDT_DELAY)) + usleep_range(30, 125); + writel_relaxed(val, wdt->reg_base + field); + wdt->last_ping = jiffies; +} + +static void wdt_write_nosleep(struct sama5d4_wdt *wdt, u32 field, u32 val) +{ + if (time_before(jiffies, wdt->last_ping + WDT_DELAY)) + udelay(123); + writel_relaxed(val, wdt->reg_base + field); + wdt->last_ping = jiffies; +} + +static int sama5d4_wdt_start(struct watchdog_device *wdd) +{ + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); + + if (wdt->sam9x60_support) { + writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IER); + wdt->mr &= ~AT91_SAM9X60_WDDIS; + } else { + wdt->mr &= ~AT91_WDT_WDDIS; + } + wdt_write(wdt, AT91_WDT_MR, wdt->mr); + + return 0; +} + +static int sama5d4_wdt_stop(struct watchdog_device *wdd) +{ + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); + + if (wdt->sam9x60_support) { + writel_relaxed(wdt->ir, wdt->reg_base + AT91_SAM9X60_IDR); + wdt->mr |= AT91_SAM9X60_WDDIS; + } else { + wdt->mr |= AT91_WDT_WDDIS; + } + wdt_write(wdt, AT91_WDT_MR, wdt->mr); + + return 0; +} + +static int sama5d4_wdt_ping(struct watchdog_device *wdd) +{ + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); + + wdt_write(wdt, AT91_WDT_CR, AT91_WDT_KEY | AT91_WDT_WDRSTT); + + return 0; +} + +static int sama5d4_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct sama5d4_wdt *wdt = watchdog_get_drvdata(wdd); + u32 value = WDT_SEC2TICKS(timeout); + + if (wdt->sam9x60_support) { + wdt_write(wdt, AT91_SAM9X60_WLR, + AT91_SAM9X60_SET_COUNTER(value)); + + wdd->timeout = timeout; + return 0; + } + + wdt->mr &= ~AT91_WDT_WDV; + wdt->mr |= AT91_WDT_SET_WDV(value); + + /* + * WDDIS has to be 0 when updating WDD/WDV. The datasheet states: When + * setting the WDDIS bit, and while it is set, the fields WDV and WDD + * must not be modified. + * If the watchdog is enabled, then the timeout can be updated. Else, + * wait that the user enables it. + */ + if (wdt_enabled) + wdt_write(wdt, AT91_WDT_MR, wdt->mr & ~AT91_WDT_WDDIS); + + wdd->timeout = timeout; + + return 0; +} + +static const struct watchdog_info sama5d4_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .identity = "Atmel SAMA5D4 Watchdog", +}; + +static const struct watchdog_ops sama5d4_wdt_ops = { + .owner = THIS_MODULE, + .start = sama5d4_wdt_start, + .stop = sama5d4_wdt_stop, + .ping = sama5d4_wdt_ping, + .set_timeout = sama5d4_wdt_set_timeout, +}; + +static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id) +{ + struct sama5d4_wdt *wdt = platform_get_drvdata(dev_id); + u32 reg; + + if (wdt->sam9x60_support) + reg = wdt_read(wdt, AT91_SAM9X60_ISR); + else + reg = wdt_read(wdt, AT91_WDT_SR); + + if (reg) { + pr_crit("Atmel Watchdog Software Reset\n"); + emergency_restart(); + pr_crit("Reboot didn't succeed\n"); + } + + return IRQ_HANDLED; +} + +static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt) +{ + const char *tmp; + + if (wdt->sam9x60_support) + wdt->mr = AT91_SAM9X60_WDDIS; + else + wdt->mr = AT91_WDT_WDDIS; + + if (!of_property_read_string(np, "atmel,watchdog-type", &tmp) && + !strcmp(tmp, "software")) + wdt->need_irq = true; + + if (of_property_read_bool(np, "atmel,idle-halt")) + wdt->mr |= AT91_WDT_WDIDLEHLT; + + if (of_property_read_bool(np, "atmel,dbg-halt")) + wdt->mr |= AT91_WDT_WDDBGHLT; + + return 0; +} + +static int sama5d4_wdt_init(struct sama5d4_wdt *wdt) +{ + u32 reg, val; + + val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT); + /* + * When booting and resuming, the bootloader may have changed the + * watchdog configuration. + * If the watchdog is already running, we can safely update it. + * Else, we have to disable it properly. + */ + if (!wdt_enabled) { + reg = wdt_read(wdt, AT91_WDT_MR); + if (wdt->sam9x60_support && (!(reg & AT91_SAM9X60_WDDIS))) + wdt_write_nosleep(wdt, AT91_WDT_MR, + reg | AT91_SAM9X60_WDDIS); + else if (!wdt->sam9x60_support && + (!(reg & AT91_WDT_WDDIS))) + wdt_write_nosleep(wdt, AT91_WDT_MR, + reg | AT91_WDT_WDDIS); + } + + if (wdt->sam9x60_support) { + if (wdt->need_irq) + wdt->ir = AT91_SAM9X60_PERINT; + else + wdt->mr |= AT91_SAM9X60_PERIODRST; + + wdt_write(wdt, AT91_SAM9X60_IER, wdt->ir); + wdt_write(wdt, AT91_SAM9X60_WLR, AT91_SAM9X60_SET_COUNTER(val)); + } else { + wdt->mr |= AT91_WDT_SET_WDD(WDT_SEC2TICKS(MAX_WDT_TIMEOUT)); + wdt->mr |= AT91_WDT_SET_WDV(val); + + if (wdt->need_irq) + wdt->mr |= AT91_WDT_WDFIEN; + else + wdt->mr |= AT91_WDT_WDRSTEN; + } + + wdt_write_nosleep(wdt, AT91_WDT_MR, wdt->mr); + + return 0; +} + +static int sama5d4_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct watchdog_device *wdd; + struct sama5d4_wdt *wdt; + void __iomem *regs; + u32 irq = 0; + int ret; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdd = &wdt->wdd; + wdd->timeout = WDT_DEFAULT_TIMEOUT; + wdd->info = &sama5d4_wdt_info; + wdd->ops = &sama5d4_wdt_ops; + wdd->min_timeout = MIN_WDT_TIMEOUT; + wdd->max_timeout = MAX_WDT_TIMEOUT; + wdt->last_ping = jiffies; + wdt->sam9x60_support = of_device_is_compatible(dev->of_node, + "microchip,sam9x60-wdt"); + + watchdog_set_drvdata(wdd, wdt); + + regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(regs)) + return PTR_ERR(regs); + + wdt->reg_base = regs; + + ret = of_sama5d4_wdt_init(dev->of_node, wdt); + if (ret) + return ret; + + if (wdt->need_irq) { + irq = irq_of_parse_and_map(dev->of_node, 0); + if (!irq) { + dev_warn(dev, "failed to get IRQ from DT\n"); + wdt->need_irq = false; + } + } + + if (wdt->need_irq) { + ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler, + IRQF_SHARED | IRQF_IRQPOLL | + IRQF_NO_SUSPEND, pdev->name, pdev); + if (ret) { + dev_err(dev, "cannot register interrupt handler\n"); + return ret; + } + } + + watchdog_init_timeout(wdd, wdt_timeout, dev); + + ret = sama5d4_wdt_init(wdt); + if (ret) + return ret; + + watchdog_set_nowayout(wdd, nowayout); + + watchdog_stop_on_unregister(wdd); + ret = devm_watchdog_register_device(dev, wdd); + if (ret) + return ret; + + platform_set_drvdata(pdev, wdt); + + dev_info(dev, "initialized (timeout = %d sec, nowayout = %d)\n", + wdd->timeout, nowayout); + + return 0; +} + +static const struct of_device_id sama5d4_wdt_of_match[] = { + { + .compatible = "atmel,sama5d4-wdt", + }, + { + .compatible = "microchip,sam9x60-wdt", + }, + { } +}; +MODULE_DEVICE_TABLE(of, sama5d4_wdt_of_match); + +#ifdef CONFIG_PM_SLEEP +static int sama5d4_wdt_suspend_late(struct device *dev) +{ + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + sama5d4_wdt_stop(&wdt->wdd); + + return 0; +} + +static int sama5d4_wdt_resume_early(struct device *dev) +{ + struct sama5d4_wdt *wdt = dev_get_drvdata(dev); + + /* + * FIXME: writing MR also pings the watchdog which may not be desired. + * This should only be done when the registers are lost on suspend but + * there is no way to get this information right now. + */ + sama5d4_wdt_init(wdt); + + if (watchdog_active(&wdt->wdd)) + sama5d4_wdt_start(&wdt->wdd); + + return 0; +} +#endif + +static const struct dev_pm_ops sama5d4_wdt_pm_ops = { + SET_LATE_SYSTEM_SLEEP_PM_OPS(sama5d4_wdt_suspend_late, + sama5d4_wdt_resume_early) +}; + +static struct platform_driver sama5d4_wdt_driver = { + .probe = sama5d4_wdt_probe, + .driver = { + .name = "sama5d4_wdt", + .pm = &sama5d4_wdt_pm_ops, + .of_match_table = sama5d4_wdt_of_match, + } +}; +module_platform_driver(sama5d4_wdt_driver); + +MODULE_AUTHOR("Atmel Corporation"); +MODULE_DESCRIPTION("Atmel SAMA5D4 Watchdog Timer driver"); +MODULE_LICENSE("GPL v2"); |