// SPDX-License-Identifier: GPL-2.0 /* * IXP4 timer driver * Copyright (C) 2019 Linus Walleij <[email protected]> * * Based on arch/arm/mach-ixp4xx/common.c * Copyright 2002 (C) Intel Corporation * Copyright 2003-2004 (C) MontaVista, Software, Inc. * Copyright (C) Deepak Saxena <[email protected]> */ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/clockchips.h> #include <linux/clocksource.h> #include <linux/sched_clock.h> #include <linux/slab.h> #include <linux/bitops.h> #include <linux/delay.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/platform_device.h> /* * Constants to make it easy to access Timer Control/Status registers */ #define IXP4XX_OSTS_OFFSET … #define IXP4XX_OST1_OFFSET … #define IXP4XX_OSRT1_OFFSET … #define IXP4XX_OST2_OFFSET … #define IXP4XX_OSRT2_OFFSET … #define IXP4XX_OSST_OFFSET … /* * Timer register values and bit definitions */ #define IXP4XX_OST_ENABLE … #define IXP4XX_OST_ONE_SHOT … /* Low order bits of reload value ignored */ #define IXP4XX_OST_RELOAD_MASK … #define IXP4XX_OST_DISABLED … #define IXP4XX_OSST_TIMER_1_PEND … #define IXP4XX_OSST_TIMER_2_PEND … #define IXP4XX_OSST_TIMER_TS_PEND … /* Remaining registers are for the watchdog and defined in the watchdog driver */ struct ixp4xx_timer { … }; /* * A local singleton used by sched_clock and delay timer reads, which are * fast and stateless */ static struct ixp4xx_timer *local_ixp4xx_timer; static inline struct ixp4xx_timer * to_ixp4xx_timer(struct clock_event_device *evt) { … } static unsigned long ixp4xx_read_timer(void) { … } static u64 notrace ixp4xx_read_sched_clock(void) { … } static u64 ixp4xx_clocksource_read(struct clocksource *c) { … } static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id) { … } static int ixp4xx_set_next_event(unsigned long cycles, struct clock_event_device *evt) { … } static int ixp4xx_shutdown(struct clock_event_device *evt) { … } static int ixp4xx_set_oneshot(struct clock_event_device *evt) { … } static int ixp4xx_set_periodic(struct clock_event_device *evt) { … } static int ixp4xx_resume(struct clock_event_device *evt) { … } /* * IXP4xx timer tick * We use OS timer1 on the CPU for the timer tick and the timestamp * counter as a source of real clock ticks to account for missed jiffies. */ static __init int ixp4xx_timer_register(void __iomem *base, int timer_irq, unsigned int timer_freq) { … } static struct platform_device ixp4xx_watchdog_device = …; /* * This probe gets called after the timer is already up and running. The main * function on this platform is to spawn the watchdog device as a child. */ static int ixp4xx_timer_probe(struct platform_device *pdev) { … } static const struct of_device_id ixp4xx_timer_dt_id[] = …; static struct platform_driver ixp4xx_timer_driver = …; builtin_platform_driver(…) …; static __init int ixp4xx_of_timer_init(struct device_node *np) { … } TIMER_OF_DECLARE(ixp4xx, "intel,ixp4xx-timer", ixp4xx_of_timer_init);
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