[linux-2.6-block.git] / drivers / clocksource / timer-ti-32k.c

// SPDX-License-Identifier: GPL-2.0-only
/**
 * timer-ti-32k.c - OMAP2 32k Timer Support
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Update to use new clocksource/clockevent layers
 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
 * Copyright (C) 2007 MontaVista Software, Inc.
 *
 * Original driver:
 * Copyright (C) 2005 Nokia Corporation
 * Author: Paul Mundt <paul.mundt@nokia.com>
 *         Juha Yrjölä <juha.yrjola@nokia.com>
 * OMAP Dual-mode timer framework support by Timo Teras
 *
 * Some parts based off of TI's 24xx code:
 *
 * Copyright (C) 2004-2009 Texas Instruments, Inc.
 *
 * Roughly modelled after the OMAP1 MPU timer code.
 * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
 *
 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
 */

#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched_clock.h>
#include <linux/clocksource.h>
#include <linux/of.h>
#include <linux/of_address.h>

/*
 * 32KHz clocksource ... always available, on pretty most chips except
 * OMAP 730 and 1510.  Other timers could be used as clocksources, with
 * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
 * but systems won't necessarily want to spend resources that way.
 */

#define OMAP2_32KSYNCNT_REV_OFF		0x0
#define OMAP2_32KSYNCNT_REV_SCHEME	(0x3 << 30)
#define OMAP2_32KSYNCNT_CR_OFF_LOW	0x10
#define OMAP2_32KSYNCNT_CR_OFF_HIGH	0x30

struct ti_32k {
	void __iomem		*base;
	void __iomem		*counter;
	struct clocksource	cs;
};

static inline struct ti_32k *to_ti_32k(struct clocksource *cs)
{
	return container_of(cs, struct ti_32k, cs);
}

static u64 notrace ti_32k_read_cycles(struct clocksource *cs)
{
	struct ti_32k *ti = to_ti_32k(cs);

	return (u64)readl_relaxed(ti->counter);
}

static struct ti_32k ti_32k_timer = {
	.cs = {
		.name		= "32k_counter",
		.rating		= 250,
		.read		= ti_32k_read_cycles,
		.mask		= CLOCKSOURCE_MASK(32),
		.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
	},
};

static u64 notrace omap_32k_read_sched_clock(void)
{
	return ti_32k_read_cycles(&ti_32k_timer.cs);
}

static int __init ti_32k_timer_init(struct device_node *np)
{
	int ret;

	ti_32k_timer.base = of_iomap(np, 0);
	if (!ti_32k_timer.base) {
		pr_err("Can't ioremap 32k timer base\n");
		return -ENXIO;
	}

	if (!of_machine_is_compatible("ti,am43"))
		ti_32k_timer.cs.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;

	ti_32k_timer.counter = ti_32k_timer.base;

	/*
	 * 32k sync Counter IP register offsets vary between the highlander
	 * version and the legacy ones.
	 *
	 * The 'SCHEME' bits(30-31) of the revision register is used to identify
	 * the version.
	 */
	if (readl_relaxed(ti_32k_timer.base + OMAP2_32KSYNCNT_REV_OFF) &
			OMAP2_32KSYNCNT_REV_SCHEME)
		ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_HIGH;
	else
		ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_LOW;

	ret = clocksource_register_hz(&ti_32k_timer.cs, 32768);
	if (ret) {
		pr_err("32k_counter: can't register clocksource\n");
		return ret;
	}

	sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
	pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");

	return 0;
}
TIMER_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k",
		ti_32k_timer_init);
Commit	Line	Data
6b1baefe	1	// SPDX-License-Identifier: GPL-2.0-only
fe851f56 FB	2	/**
	3	* timer-ti-32k.c - OMAP2 32k Timer Support
	4	*
	5	* Copyright (C) 2009 Nokia Corporation
	6	*
	7	* Update to use new clocksource/clockevent layers
	8	* Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
	9	* Copyright (C) 2007 MontaVista Software, Inc.
	10	*
	11	* Original driver:
	12	* Copyright (C) 2005 Nokia Corporation
	13	* Author: Paul Mundt <paul.mundt@nokia.com>
	14	* Juha Yrjölä <juha.yrjola@nokia.com>
	15	* OMAP Dual-mode timer framework support by Timo Teras
	16	*
	17	* Some parts based off of TI's 24xx code:
	18	*
	19	* Copyright (C) 2004-2009 Texas Instruments, Inc.
	20	*
	21	* Roughly modelled after the OMAP1 MPU timer code.
	22	* Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
	23	*
	24	* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
fe851f56 FB	25	*/
	26
	27	#include <linux/init.h>
	28	#include <linux/time.h>
	29	#include <linux/sched_clock.h>
	30	#include <linux/clocksource.h>
	31	#include <linux/of.h>
	32	#include <linux/of_address.h>
	33
	34	/*
	35	* 32KHz clocksource ... always available, on pretty most chips except
	36	* OMAP 730 and 1510. Other timers could be used as clocksources, with
	37	* higher resolution in free-running counter modes (e.g. 12 MHz xtal),
	38	* but systems won't necessarily want to spend resources that way.
	39	*/
	40
	41	#define OMAP2_32KSYNCNT_REV_OFF 0x0
	42	#define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30)
	43	#define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10
	44	#define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30
	45
	46	struct ti_32k {
	47	void __iomem *base;
	48	void __iomem *counter;
	49	struct clocksource cs;
	50	};
	51
	52	static inline struct ti_32k to_ti_32k(struct clocksource cs)
	53	{
	54	return container_of(cs, struct ti_32k, cs);
	55	}
	56
a5a1d1c2	57	static u64 notrace ti_32k_read_cycles(struct clocksource *cs)
fe851f56 FB	58	{
	59	struct ti_32k *ti = to_ti_32k(cs);
	60
a5a1d1c2	61	return (u64)readl_relaxed(ti->counter);
fe851f56 FB	62	}
	63
	64	static struct ti_32k ti_32k_timer = {
	65	.cs = {
	66	.name = "32k_counter",
	67	.rating = 250,
	68	.read = ti_32k_read_cycles,
	69	.mask = CLOCKSOURCE_MASK(32),
c77aee71	70	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
fe851f56 FB	71	},
	72	};
	73
	74	static u64 notrace omap_32k_read_sched_clock(void)
	75	{
	76	return ti_32k_read_cycles(&ti_32k_timer.cs);
	77	}
	78
0a8e7d49	79	static int __init ti_32k_timer_init(struct device_node *np)
fe851f56 FB	80	{
	81	int ret;
	82
	83	ti_32k_timer.base = of_iomap(np, 0);
	84	if (!ti_32k_timer.base) {
	85	pr_err("Can't ioremap 32k timer base\n");
0a8e7d49	86	return -ENXIO;
fe851f56 FB	87	}
fe851f56 FB	88
3b7d96a0 K	89	if (!of_machine_is_compatible("ti,am43"))
	90	ti_32k_timer.cs.flags \|= CLOCK_SOURCE_SUSPEND_NONSTOP;
	91
fe851f56 FB	92	ti_32k_timer.counter = ti_32k_timer.base;
	93
	94	/*
	95	* 32k sync Counter IP register offsets vary between the highlander
	96	* version and the legacy ones.
	97	*
	98	* The 'SCHEME' bits(30-31) of the revision register is used to identify
	99	* the version.
	100	*/
	101	if (readl_relaxed(ti_32k_timer.base + OMAP2_32KSYNCNT_REV_OFF) &
	102	OMAP2_32KSYNCNT_REV_SCHEME)
	103	ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_HIGH;
	104	else
	105	ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_LOW;
	106
	107	ret = clocksource_register_hz(&ti_32k_timer.cs, 32768);
	108	if (ret) {
	109	pr_err("32k_counter: can't register clocksource\n");
0a8e7d49	110	return ret;
fe851f56 FB	111	}
	112
	113	sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
	114	pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
0a8e7d49 DL	115
0a8e7d49 DL	116	return 0;
fe851f56	117	}
17273395	118	TIMER_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k",
fe851f56	119	ti_32k_timer_init);