cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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clps711x-timer.c (2336B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *  Cirrus Logic CLPS711X clocksource driver
      4 *
      5 *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
      6 */
      7
      8#include <linux/clk.h>
      9#include <linux/clockchips.h>
     10#include <linux/clocksource.h>
     11#include <linux/interrupt.h>
     12#include <linux/io.h>
     13#include <linux/of_address.h>
     14#include <linux/of_irq.h>
     15#include <linux/sched_clock.h>
     16#include <linux/slab.h>
     17
     18enum {
     19	CLPS711X_CLKSRC_CLOCKSOURCE,
     20	CLPS711X_CLKSRC_CLOCKEVENT,
     21};
     22
     23static void __iomem *tcd;
     24
     25static u64 notrace clps711x_sched_clock_read(void)
     26{
     27	return ~readw(tcd);
     28}
     29
     30static void __init clps711x_clksrc_init(struct clk *clock, void __iomem *base)
     31{
     32	unsigned long rate = clk_get_rate(clock);
     33
     34	tcd = base;
     35
     36	clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
     37			      clocksource_mmio_readw_down);
     38
     39	sched_clock_register(clps711x_sched_clock_read, 16, rate);
     40}
     41
     42static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id)
     43{
     44	struct clock_event_device *evt = dev_id;
     45
     46	evt->event_handler(evt);
     47
     48	return IRQ_HANDLED;
     49}
     50
     51static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base,
     52					unsigned int irq)
     53{
     54	struct clock_event_device *clkevt;
     55	unsigned long rate;
     56
     57	clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
     58	if (!clkevt)
     59		return -ENOMEM;
     60
     61	rate = clk_get_rate(clock);
     62
     63	/* Set Timer prescaler */
     64	writew(DIV_ROUND_CLOSEST(rate, HZ), base);
     65
     66	clkevt->name = "clps711x-clockevent";
     67	clkevt->rating = 300;
     68	clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP;
     69	clkevt->cpumask = cpumask_of(0);
     70	clockevents_config_and_register(clkevt, HZ, 0, 0);
     71
     72	return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
     73			   "clps711x-timer", clkevt);
     74}
     75
     76static int __init clps711x_timer_init(struct device_node *np)
     77{
     78	unsigned int irq = irq_of_parse_and_map(np, 0);
     79	struct clk *clock = of_clk_get(np, 0);
     80	void __iomem *base = of_iomap(np, 0);
     81
     82	if (!base)
     83		return -ENOMEM;
     84	if (!irq)
     85		return -EINVAL;
     86	if (IS_ERR(clock))
     87		return PTR_ERR(clock);
     88
     89	switch (of_alias_get_id(np, "timer")) {
     90	case CLPS711X_CLKSRC_CLOCKSOURCE:
     91		clps711x_clksrc_init(clock, base);
     92		break;
     93	case CLPS711X_CLKSRC_CLOCKEVENT:
     94		return _clps711x_clkevt_init(clock, base, irq);
     95	default:
     96		return -EINVAL;
     97	}
     98
     99	return 0;
    100}
    101TIMER_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);