[2/7] clocksource: Add Tegra186 timers support

Message ID	20200320133452.3705040-3-thierry.reding@gmail.com
State	Deferred
Headers	show Return-Path: <linux-tegra-owner@vger.kernel.org> From: Thierry Reding <thierry.reding@gmail.com> To: Thomas Gleixner <tglx@linutronix.de>, Thierry Reding <thierry.reding@gmail.com> Cc: Rob Herring <robh+dt@kernel.org>, Jon Hunter <jonathanh@nvidia.com>, linux-tegra@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/7] clocksource: Add Tegra186 timers support Date: Fri, 20 Mar 2020 14:34:47 +0100 Message-Id: <20200320133452.3705040-3-thierry.reding@gmail.com> In-Reply-To: <20200320133452.3705040-1-thierry.reding@gmail.com> References: <20200320133452.3705040-1-thierry.reding@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk
Series	clocksource: Add NVIDIA Tegra186 timers support \| expand [0/7] clocksource: Add NVIDIA Tegra186 timers support [1/7] dt-bindings: timer: Add bindings for NVIDIA Tegra186 timers [2/7] clocksource: Add Tegra186 timers support [4/7] arm64: tegra: Add native timer support on Tegra186 [5/7] arm64: tegra: Enable native timers on Jetson TX2 [6/7] arm64: tegra: Add native timer support on Tegra194 [7/7] arm64: tegra: Enable native timers on Jetson AGX Xavier

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index f2142e6bbea3..54d1b27d1f8b 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -149,6 +149,14 @@ config TEGRA_TIMER help Enables support for the Tegra driver. +config TEGRA186_TIMER + bool "NVIDIA Tegra186 timer driver" + depends on ARCH_TEGRA || COMPILE_TEST + select TIMER_OF + help + Enables support for the timers and watchdogs found on NVIDIA + Tegra186 and later SoCs. + config VT8500_TIMER bool "VT8500 timer driver" if COMPILE_TEST depends on HAS_IOMEM diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 641ba5383ab5..ffa7950f4b7c 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_SUN4I_TIMER) += timer-sun4i.o obj-$(CONFIG_SUN5I_HSTIMER) += timer-sun5i.o obj-$(CONFIG_MESON6_TIMER) += timer-meson6.o obj-$(CONFIG_TEGRA_TIMER) += timer-tegra.o +obj-$(CONFIG_TEGRA186_TIMER) += timer-tegra186.o obj-$(CONFIG_VT8500_TIMER) += timer-vt8500.o obj-$(CONFIG_NSPIRE_TIMER) += timer-zevio.o obj-$(CONFIG_BCM_KONA_TIMER) += bcm_kona_timer.o diff --git a/drivers/clocksource/timer-tegra186.c b/drivers/clocksource/timer-tegra186.c new file mode 100644 index 000000000000..f8bdda041e3a --- /dev/null +++ b/drivers/clocksource/timer-tegra186.c @@ -0,0 +1,377 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2019-2020 NVIDIA Corporation. All rights reserved. + */ + +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/watchdog.h> + +/* shared registers */ +#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; + unsigned int irq; + + struct tegra186_wdt *wdt; +}; + +static void tmr_writel(struct tegra186_tmr *tmr, u32 value, unsigned int offset) +{ + writel(value, tmr->regs + offset); +} + +static void wdt_writel(struct tegra186_wdt *wdt, u32 value, unsigned int offset) +{ + writel(value, wdt->regs + offset); +} + +static u32 wdt_readl(struct tegra186_wdt *wdt, unsigned int offset) +{ + return readl(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); + + tegra186_wdt_disable(wdt); + wdt->base.timeout = timeout; + 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 irqreturn_t tegra186_timer_irq(int irq, void *data) +{ + struct tegra186_timer *tegra = data; + + if (tegra->wdt) { + tegra186_wdt_disable(tegra->wdt); + tegra186_wdt_enable(tegra->wdt); + } + + return IRQ_HANDLED; +} + +static int tegra186_timer_probe(struct platform_device *pdev) +{ + struct tegra186_timer *tegra; + int err; + + tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL); + if (!tegra) + return -ENOMEM; + + tegra->soc = of_device_get_match_data(&pdev->dev); + dev_set_drvdata(&pdev->dev, tegra); + tegra->dev = &pdev->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) { + dev_err(tegra->dev, "failed to get interrupt #0: %d\n", err); + return err; + } + + tegra->irq = err; + + err = devm_request_irq(tegra->dev, tegra->irq, tegra186_timer_irq, + IRQF_ONESHOT | IRQF_TRIGGER_HIGH, + "tegra186-timer", tegra); + if (err < 0) { + dev_err(tegra->dev, "failed to request IRQ#%u: %d\n", + tegra->irq, err); + return 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(&pdev->dev, "failed to create WDT: %d\n", err); + return err; + } + + return 0; +} + +static int __maybe_unused tegra186_timer_suspend(struct device *dev) +{ + return 0; +} + +static int __maybe_unused tegra186_timer_resume(struct device *dev) +{ + 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 of_device_id tegra186_timer_of_match[] = { + { .compatible = "nvidia,tegra186-timer", .data = &tegra186_timer }, + { } +}; + +static struct platform_driver tegra186_wdt_driver = { + .driver = { + .name = "tegra186-timer", + .pm = &tegra186_timer_pm_ops, + .of_match_table = tegra186_timer_of_match, + .suppress_bind_attrs = true, + }, + .probe = tegra186_timer_probe, +}; +module_platform_driver(tegra186_wdt_driver); + +MODULE_AUTHOR("Thierry Reding <treding@nvidia.com>"); +MODULE_DESCRIPTION("NVIDIA Tegra186 timers driver"); +MODULE_LICENSE("GPL v2");

[2/7] clocksource: Add Tegra186 timers support

Commit Message

Comments

Patch