[linux.git] / drivers / clocksource / clps711x-timer.c

/*
 *  Cirrus Logic CLPS711X clocksource driver
 *
 *  Copyright (C) 2014 Alexander Shiyan <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/sched_clock.h>
#include <linux/slab.h>

enum {
	CLPS711X_CLKSRC_CLOCKSOURCE,
	CLPS711X_CLKSRC_CLOCKEVENT,
};

static void __iomem *tcd;

static u64 notrace clps711x_sched_clock_read(void)
{
	return ~readw(tcd);
}

static int __init _clps711x_clksrc_init(struct clk *clock, void __iomem *base)
{
	unsigned long rate;

	if (!base)
		return -ENOMEM;
	if (IS_ERR(clock))
		return PTR_ERR(clock);

	rate = clk_get_rate(clock);

	tcd = base;

	clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
			      clocksource_mmio_readw_down);

	sched_clock_register(clps711x_sched_clock_read, 16, rate);

	return 0;
}

static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = dev_id;

	evt->event_handler(evt);

	return IRQ_HANDLED;
}

static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base,
					unsigned int irq)
{
	struct clock_event_device *clkevt;
	unsigned long rate;

	if (!irq)
		return -EINVAL;
	if (!base)
		return -ENOMEM;
	if (IS_ERR(clock))
		return PTR_ERR(clock);

	clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
	if (!clkevt)
		return -ENOMEM;

	rate = clk_get_rate(clock);

	/* Set Timer prescaler */
	writew(DIV_ROUND_CLOSEST(rate, HZ), base);

	clkevt->name = "clps711x-clockevent";
	clkevt->rating = 300;
	clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP;
	clkevt->cpumask = cpumask_of(0);
	clockevents_config_and_register(clkevt, HZ, 0, 0);

	return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
			   "clps711x-timer", clkevt);
}

void __init clps711x_clksrc_init(void __iomem *tc1_base, void __iomem *tc2_base,
				 unsigned int irq)
{
	struct clk *tc1 = clk_get_sys("clps711x-timer.0", NULL);
	struct clk *tc2 = clk_get_sys("clps711x-timer.1", NULL);

	BUG_ON(_clps711x_clksrc_init(tc1, tc1_base));
	BUG_ON(_clps711x_clkevt_init(tc2, tc2_base, irq));
}

#ifdef CONFIG_CLKSRC_OF
static int __init clps711x_timer_init(struct device_node *np)
{
	unsigned int irq = irq_of_parse_and_map(np, 0);
	struct clk *clock = of_clk_get(np, 0);
	void __iomem *base = of_iomap(np, 0);

	switch (of_alias_get_id(np, "timer")) {
	case CLPS711X_CLKSRC_CLOCKSOURCE:
		return _clps711x_clksrc_init(clock, base);
	case CLPS711X_CLKSRC_CLOCKEVENT:
		return _clps711x_clkevt_init(clock, base, irq);
	default:
		return -EINVAL;
	}
}
CLOCKSOURCE_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);
#endif
Commit	Line	Data
f0b7fabe AS	1	/*
	2	* Cirrus Logic CLPS711X clocksource driver
	3	*
	4	* Copyright (C) 2014 Alexander Shiyan <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*/
	11
	12	#include <linux/clk.h>
	13	#include <linux/clockchips.h>
	14	#include <linux/clocksource.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/io.h>
	17	#include <linux/of_address.h>
	18	#include <linux/of_irq.h>
	19	#include <linux/sched_clock.h>
	20	#include <linux/slab.h>
	21
	22	enum {
	23	CLPS711X_CLKSRC_CLOCKSOURCE,
	24	CLPS711X_CLKSRC_CLOCKEVENT,
	25	};
	26
	27	static void __iomem *tcd;
	28
	29	static u64 notrace clps711x_sched_clock_read(void)
	30	{
	31	return ~readw(tcd);
	32	}
	33
	34	static int __init _clps711x_clksrc_init(struct clk clock, void __iomem base)
	35	{
	36	unsigned long rate;
	37
	38	if (!base)
	39	return -ENOMEM;
	40	if (IS_ERR(clock))
	41	return PTR_ERR(clock);
	42
	43	rate = clk_get_rate(clock);
	44
	45	tcd = base;
	46
	47	clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
	48	clocksource_mmio_readw_down);
	49
	50	sched_clock_register(clps711x_sched_clock_read, 16, rate);
	51
	52	return 0;
	53	}
	54
	55	static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id)
	56	{
	57	struct clock_event_device *evt = dev_id;
	58
	59	evt->event_handler(evt);
	60
	61	return IRQ_HANDLED;
	62	}
	63
f0b7fabe AS	64	static int __init _clps711x_clkevt_init(struct clk clock, void __iomem base,
	65	unsigned int irq)
	66	{
	67	struct clock_event_device *clkevt;
	68	unsigned long rate;
	69
	70	if (!irq)
	71	return -EINVAL;
	72	if (!base)
	73	return -ENOMEM;
	74	if (IS_ERR(clock))
	75	return PTR_ERR(clock);
	76
	77	clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
	78	if (!clkevt)
	79	return -ENOMEM;
	80
	81	rate = clk_get_rate(clock);
	82
	83	/* Set Timer prescaler */
	84	writew(DIV_ROUND_CLOSEST(rate, HZ), base);
	85
	86	clkevt->name = "clps711x-clockevent";
	87	clkevt->rating = 300;
	88	clkevt->features = CLOCK_EVT_FEAT_PERIODIC \| CLOCK_EVT_FEAT_C3STOP;
f0b7fabe AS	89	clkevt->cpumask = cpumask_of(0);
	90	clockevents_config_and_register(clkevt, HZ, 0, 0);
	91
	92	return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
	93	"clps711x-timer", clkevt);
	94	}
	95
	96	void __init clps711x_clksrc_init(void __iomem tc1_base, void __iomem tc2_base,
	97	unsigned int irq)
	98	{
	99	struct clk *tc1 = clk_get_sys("clps711x-timer.0", NULL);
	100	struct clk *tc2 = clk_get_sys("clps711x-timer.1", NULL);
	101
	102	BUG_ON(_clps711x_clksrc_init(tc1, tc1_base));
	103	BUG_ON(_clps711x_clkevt_init(tc2, tc2_base, irq));
	104	}
	105
	106	#ifdef CONFIG_CLKSRC_OF
04410efb	107	static int __init clps711x_timer_init(struct device_node *np)
f0b7fabe AS	108	{
	109	unsigned int irq = irq_of_parse_and_map(np, 0);
	110	struct clk *clock = of_clk_get(np, 0);
	111	void __iomem *base = of_iomap(np, 0);
	112
	113	switch (of_alias_get_id(np, "timer")) {
	114	case CLPS711X_CLKSRC_CLOCKSOURCE:
04410efb	115	return _clps711x_clksrc_init(clock, base);
f0b7fabe	116	case CLPS711X_CLKSRC_CLOCKEVENT:
04410efb	117	return _clps711x_clkevt_init(clock, base, irq);
f0b7fabe	118	default:
04410efb	119	return -EINVAL;
f0b7fabe AS	120	}
f0b7fabe AS	121	}
d64c0105	122	CLOCKSOURCE_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);
f0b7fabe	123	#endif