// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2019-2020 NVIDIA Corporation. All rights reserved. */ #include #include #include #include #include #include #include #include /* shared registers */ #define TKETSC0 0x000 #define TKETSC1 0x004 #define TKEUSEC 0x008 #define TKEOSC 0x00c #define TKEIE(x) (0x100 + ((x) * 4)) #define TKEIE_WDT_MASK(x, y) ((y) << (16 + 4 * (x))) /* timer registers */ #define TMRCR 0x000 #define TMRCR_ENABLE BIT(31) #define TMRCR_PERIODIC BIT(30) #define TMRCR_PTV(x) ((x) & 0x0fffffff) #define TMRSR 0x004 #define TMRSR_INTR_CLR BIT(30) #define TMRCSSR 0x008 #define TMRCSSR_SRC_USEC (0 << 0) /* watchdog registers */ #define WDTCR 0x000 #define WDTCR_SYSTEM_POR_RESET_ENABLE BIT(16) #define WDTCR_SYSTEM_DEBUG_RESET_ENABLE BIT(15) #define WDTCR_REMOTE_INT_ENABLE BIT(14) #define WDTCR_LOCAL_FIQ_ENABLE BIT(13) #define WDTCR_LOCAL_INT_ENABLE BIT(12) #define WDTCR_PERIOD_MASK (0xff << 4) #define WDTCR_PERIOD(x) (((x) & 0xff) << 4) #define WDTCR_TIMER_SOURCE_MASK 0xf #define WDTCR_TIMER_SOURCE(x) ((x) & 0xf) #define WDTCMDR 0x008 #define WDTCMDR_DISABLE_COUNTER BIT(1) #define WDTCMDR_START_COUNTER BIT(0) #define WDTUR 0x00c #define WDTUR_UNLOCK_PATTERN 0x0000c45a struct tegra186_timer_soc { unsigned int num_timers; unsigned int num_wdts; }; struct tegra186_tmr { struct tegra186_timer *parent; void __iomem *regs; unsigned int index; unsigned int hwirq; }; struct tegra186_wdt { struct watchdog_device base; void __iomem *regs; unsigned int index; bool locked; struct tegra186_tmr *tmr; }; static inline struct tegra186_wdt *to_tegra186_wdt(struct watchdog_device *wdd) { return container_of(wdd, struct tegra186_wdt, base); } struct tegra186_timer { const struct tegra186_timer_soc *soc; struct device *dev; void __iomem *regs; struct tegra186_wdt *wdt; struct clocksource usec; struct clocksource tsc; struct clocksource osc; }; static void tmr_writel(struct tegra186_tmr *tmr, u32 value, unsigned int offset) { writel_relaxed(value, tmr->regs + offset); } static void wdt_writel(struct tegra186_wdt *wdt, u32 value, unsigned int offset) { writel_relaxed(value, wdt->regs + offset); } static u32 wdt_readl(struct tegra186_wdt *wdt, unsigned int offset) { return readl_relaxed(wdt->regs + offset); } static struct tegra186_tmr *tegra186_tmr_create(struct tegra186_timer *tegra, unsigned int index) { unsigned int offset = 0x10000 + index * 0x10000; struct tegra186_tmr *tmr; tmr = devm_kzalloc(tegra->dev, sizeof(*tmr), GFP_KERNEL); if (!tmr) return ERR_PTR(-ENOMEM); tmr->parent = tegra; tmr->regs = tegra->regs + offset; tmr->index = index; tmr->hwirq = 0; return tmr; } static const struct watchdog_info tegra186_wdt_info = { .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .identity = "NVIDIA Tegra186 WDT", }; static void tegra186_wdt_disable(struct tegra186_wdt *wdt) { /* unlock and disable the watchdog */ wdt_writel(wdt, WDTUR_UNLOCK_PATTERN, WDTUR); wdt_writel(wdt, WDTCMDR_DISABLE_COUNTER, WDTCMDR); /* disable timer */ tmr_writel(wdt->tmr, 0, TMRCR); } static void tegra186_wdt_enable(struct tegra186_wdt *wdt) { struct tegra186_timer *tegra = wdt->tmr->parent; u32 value; /* unmask hardware IRQ, this may have been lost across powergate */ value = TKEIE_WDT_MASK(wdt->index, 1); writel(value, tegra->regs + TKEIE(wdt->tmr->hwirq)); /* clear interrupt */ tmr_writel(wdt->tmr, TMRSR_INTR_CLR, TMRSR); /* select microsecond source */ tmr_writel(wdt->tmr, TMRCSSR_SRC_USEC, TMRCSSR); /* configure timer (system reset happens on the fifth expiration) */ value = TMRCR_PTV(wdt->base.timeout * USEC_PER_SEC / 5) | TMRCR_PERIODIC | TMRCR_ENABLE; tmr_writel(wdt->tmr, value, TMRCR); if (!wdt->locked) { value = wdt_readl(wdt, WDTCR); /* select the proper timer source */ value &= ~WDTCR_TIMER_SOURCE_MASK; value |= WDTCR_TIMER_SOURCE(wdt->tmr->index); /* single timer period since that's already configured */ value &= ~WDTCR_PERIOD_MASK; value |= WDTCR_PERIOD(1); /* enable local interrupt for WDT petting */ value |= WDTCR_LOCAL_INT_ENABLE; /* enable local FIQ and remote interrupt for debug dump */ if (0) value |= WDTCR_REMOTE_INT_ENABLE | WDTCR_LOCAL_FIQ_ENABLE; /* enable system debug reset (doesn't properly reboot) */ if (0) value |= WDTCR_SYSTEM_DEBUG_RESET_ENABLE; /* enable system POR reset */ value |= WDTCR_SYSTEM_POR_RESET_ENABLE; wdt_writel(wdt, value, WDTCR); } wdt_writel(wdt, WDTCMDR_START_COUNTER, WDTCMDR); } static int tegra186_wdt_start(struct watchdog_device *wdd) { struct tegra186_wdt *wdt = to_tegra186_wdt(wdd); tegra186_wdt_enable(wdt); return 0; } static int tegra186_wdt_stop(struct watchdog_device *wdd) { struct tegra186_wdt *wdt = to_tegra186_wdt(wdd); tegra186_wdt_disable(wdt); return 0; } static int tegra186_wdt_ping(struct watchdog_device *wdd) { struct tegra186_wdt *wdt = to_tegra186_wdt(wdd); tegra186_wdt_disable(wdt); tegra186_wdt_enable(wdt); return 0; } static int tegra186_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { struct tegra186_wdt *wdt = to_tegra186_wdt(wdd); if (watchdog_active(&wdt->base)) tegra186_wdt_disable(wdt); wdt->base.timeout = timeout; if (watchdog_active(&wdt->base)) tegra186_wdt_enable(wdt); return 0; } static const struct watchdog_ops tegra186_wdt_ops = { .owner = THIS_MODULE, .start = tegra186_wdt_start, .stop = tegra186_wdt_stop, .ping = tegra186_wdt_ping, .set_timeout = tegra186_wdt_set_timeout, }; static struct tegra186_wdt *tegra186_wdt_create(struct tegra186_timer *tegra, unsigned int index) { unsigned int offset = 0x10000, source; struct tegra186_wdt *wdt; u32 value; int err; offset += tegra->soc->num_timers * 0x10000 + index * 0x10000; wdt = devm_kzalloc(tegra->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return ERR_PTR(-ENOMEM); wdt->regs = tegra->regs + offset; wdt->index = index; /* read the watchdog configuration since it might be locked down */ value = wdt_readl(wdt, WDTCR); if (value & WDTCR_LOCAL_INT_ENABLE) wdt->locked = true; source = value & WDTCR_TIMER_SOURCE_MASK; wdt->tmr = tegra186_tmr_create(tegra, source); if (IS_ERR(wdt->tmr)) return ERR_CAST(wdt->tmr); wdt->base.info = &tegra186_wdt_info; wdt->base.ops = &tegra186_wdt_ops; wdt->base.min_timeout = 1; wdt->base.max_timeout = 255; wdt->base.parent = tegra->dev; err = watchdog_init_timeout(&wdt->base, 5, tegra->dev); if (err < 0) { dev_err(tegra->dev, "failed to initialize timeout: %d\n", err); return ERR_PTR(err); } err = devm_watchdog_register_device(tegra->dev, &wdt->base); if (err < 0) { dev_err(tegra->dev, "failed to register WDT: %d\n", err); return ERR_PTR(err); } return wdt; } static u64 tegra186_timer_tsc_read(struct clocksource *cs) { struct tegra186_timer *tegra = container_of(cs, struct tegra186_timer, tsc); u32 hi, lo, ss; hi = readl_relaxed(tegra->regs + TKETSC1); /* * The 56-bit value of the TSC is spread across two registers that are * not synchronized. In order to read them atomically, ensure that the * high 24 bits match before and after reading the low 32 bits. */ do { /* snapshot the high 24 bits */ ss = hi; lo = readl_relaxed(tegra->regs + TKETSC0); hi = readl_relaxed(tegra->regs + TKETSC1); } while (hi != ss); return (u64)hi << 32 | lo; } static int tegra186_timer_tsc_init(struct tegra186_timer *tegra) { tegra->tsc.name = "tsc"; tegra->tsc.rating = 300; tegra->tsc.read = tegra186_timer_tsc_read; tegra->tsc.mask = CLOCKSOURCE_MASK(56); tegra->tsc.flags = CLOCK_SOURCE_IS_CONTINUOUS; return clocksource_register_hz(&tegra->tsc, 31250000); } static u64 tegra186_timer_osc_read(struct clocksource *cs) { struct tegra186_timer *tegra = container_of(cs, struct tegra186_timer, osc); return readl_relaxed(tegra->regs + TKEOSC); } static int tegra186_timer_osc_init(struct tegra186_timer *tegra) { tegra->osc.name = "osc"; tegra->osc.rating = 300; tegra->osc.read = tegra186_timer_osc_read; tegra->osc.mask = CLOCKSOURCE_MASK(32); tegra->osc.flags = CLOCK_SOURCE_IS_CONTINUOUS; return clocksource_register_hz(&tegra->osc, 38400000); } static u64 tegra186_timer_usec_read(struct clocksource *cs) { struct tegra186_timer *tegra = container_of(cs, struct tegra186_timer, usec); return readl_relaxed(tegra->regs + TKEUSEC); } static int tegra186_timer_usec_init(struct tegra186_timer *tegra) { tegra->usec.name = "usec"; tegra->usec.rating = 300; tegra->usec.read = tegra186_timer_usec_read; tegra->usec.mask = CLOCKSOURCE_MASK(32); tegra->usec.flags = CLOCK_SOURCE_IS_CONTINUOUS; return clocksource_register_hz(&tegra->usec, USEC_PER_SEC); } static irqreturn_t tegra186_timer_irq(int irq, void *data) { struct tegra186_timer *tegra = data; if (watchdog_active(&tegra->wdt->base)) { tegra186_wdt_disable(tegra->wdt); tegra186_wdt_enable(tegra->wdt); } return IRQ_HANDLED; } static int tegra186_timer_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct tegra186_timer *tegra; unsigned int irq; int err; tegra = devm_kzalloc(dev, sizeof(*tegra), GFP_KERNEL); if (!tegra) return -ENOMEM; tegra->soc = of_device_get_match_data(dev); dev_set_drvdata(dev, tegra); tegra->dev = dev; tegra->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(tegra->regs)) return PTR_ERR(tegra->regs); err = platform_get_irq(pdev, 0); if (err < 0) return err; irq = err; /* create a watchdog using a preconfigured timer */ tegra->wdt = tegra186_wdt_create(tegra, 0); if (IS_ERR(tegra->wdt)) { err = PTR_ERR(tegra->wdt); dev_err(dev, "failed to create WDT: %d\n", err); return err; } err = tegra186_timer_tsc_init(tegra); if (err < 0) { dev_err(dev, "failed to register TSC counter: %d\n", err); return err; } err = tegra186_timer_osc_init(tegra); if (err < 0) { dev_err(dev, "failed to register OSC counter: %d\n", err); goto unregister_tsc; } err = tegra186_timer_usec_init(tegra); if (err < 0) { dev_err(dev, "failed to register USEC counter: %d\n", err); goto unregister_osc; } err = devm_request_irq(dev, irq, tegra186_timer_irq, 0, "tegra186-timer", tegra); if (err < 0) { dev_err(dev, "failed to request IRQ#%u: %d\n", irq, err); goto unregister_usec; } return 0; unregister_usec: clocksource_unregister(&tegra->usec); unregister_osc: clocksource_unregister(&tegra->osc); unregister_tsc: clocksource_unregister(&tegra->tsc); return err; } static void tegra186_timer_remove(struct platform_device *pdev) { struct tegra186_timer *tegra = platform_get_drvdata(pdev); clocksource_unregister(&tegra->usec); clocksource_unregister(&tegra->osc); clocksource_unregister(&tegra->tsc); } static int __maybe_unused tegra186_timer_suspend(struct device *dev) { struct tegra186_timer *tegra = dev_get_drvdata(dev); if (watchdog_active(&tegra->wdt->base)) tegra186_wdt_disable(tegra->wdt); return 0; } static int __maybe_unused tegra186_timer_resume(struct device *dev) { struct tegra186_timer *tegra = dev_get_drvdata(dev); if (watchdog_active(&tegra->wdt->base)) tegra186_wdt_enable(tegra->wdt); return 0; } static SIMPLE_DEV_PM_OPS(tegra186_timer_pm_ops, tegra186_timer_suspend, tegra186_timer_resume); static const struct tegra186_timer_soc tegra186_timer = { .num_timers = 10, .num_wdts = 3, }; static const struct tegra186_timer_soc tegra234_timer = { .num_timers = 16, .num_wdts = 3, }; static const struct of_device_id tegra186_timer_of_match[] = { { .compatible = "nvidia,tegra186-timer", .data = &tegra186_timer }, { .compatible = "nvidia,tegra234-timer", .data = &tegra234_timer }, { } }; MODULE_DEVICE_TABLE(of, tegra186_timer_of_match); static struct platform_driver tegra186_wdt_driver = { .driver = { .name = "tegra186-timer", .pm = &tegra186_timer_pm_ops, .of_match_table = tegra186_timer_of_match, }, .probe = tegra186_timer_probe, .remove = tegra186_timer_remove, }; module_platform_driver(tegra186_wdt_driver); MODULE_AUTHOR("Thierry Reding "); MODULE_DESCRIPTION("NVIDIA Tegra186 timers driver");