barebox/arch/arm/mach-imx/clocksource.c

/*
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Marius Groeger <mgroeger@sysgo.de>
 *
 * (C) Copyright 2002
 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
 * Alex Zuepke <azu@sysgo.de>
 *
 * (C) Copyright 2002
 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <common.h>
#include <init.h>
#include <clock.h>
#include <errno.h>
#include <notifier.h>
#include <mach/imx-regs.h>
#include <mach/clock.h>
#include <io.h>

/* Part 1: Registers */
# define GPT_TCTL   0x00
# define GPT_TPRER  0x04

/* Part 2: Bitfields */
#define TCTL_SWR			(1 << 15)	/* Software reset */
#define IMX1_TCTL_FRR			(1 << 8)	/* Freerun / restart */
#define IMX31_TCTL_FRR			(1 << 9)	/* Freerun / restart */
#define IMX1_TCTL_CLKSOURCE_IPG		(1 << 1)	/* Clock source bit position */
#define IMX31_TCTL_CLKSOURCE_IPG	(1 << 6)	/* Clock source bit position */
#define TCTL_TEN			(1 << 0)	/* Timer enable */

struct imx_gpt_regs {
	unsigned int tcn;
	uint32_t tctl_val;
};

static struct imx_gpt_regs regs_imx1 = {
	.tcn = 0x10,
	.tctl_val = IMX1_TCTL_FRR | IMX1_TCTL_CLKSOURCE_IPG | TCTL_TEN,
};

static struct imx_gpt_regs regs_imx31 = {
	.tcn = 0x24,
	.tctl_val = IMX31_TCTL_FRR | IMX31_TCTL_CLKSOURCE_IPG | TCTL_TEN,
};

static struct imx_gpt_regs *regs;
static void __iomem *timer_base;

static uint64_t imx_clocksource_read(void)
{
	return readl(timer_base + regs->tcn);
}

static struct clocksource cs = {
	.read	= imx_clocksource_read,
	.mask	= CLOCKSOURCE_MASK(32),
	.shift	= 10,
};

static int imx_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
{
	cs.mult = clocksource_hz2mult(imx_get_gptclk(), cs.shift);
	return 0;
}

static struct notifier_block imx_clock_notifier = {
	.notifier_call = imx_clocksource_clock_change,
};

static int imx_gpt_probe(struct device_d *dev)
{
	int i;
	int ret;

	/* one timer is enough */
	if (timer_base)
		return -EBUSY;

	ret = dev_get_drvdata(dev, (unsigned long *)&regs);
	if (ret)
		return ret;

	timer_base = dev_request_mem_region(dev, 0);

	/* setup GP Timer 1 */
	writel(TCTL_SWR, timer_base + GPT_TCTL);

#ifdef CONFIG_ARCH_IMX21
	PCCR1 |= PCCR1_GPT1_EN;
#endif
#ifdef CONFIG_ARCH_IMX27
	PCCR0 |= PCCR0_GPT1_EN;
	PCCR1 |= PCCR1_PERCLK1_EN;
#endif
#ifdef CONFIG_ARCH_IMX25
	writel(readl(IMX_CCM_BASE + CCM_CGCR1) | (1 << 19),
		IMX_CCM_BASE + CCM_CGCR1);
#endif

	for (i = 0; i < 100; i++)
		writel(0, timer_base + GPT_TCTL); /* We have no udelay by now */

	writel(0, timer_base + GPT_TPRER);
	writel(regs->tctl_val, timer_base + GPT_TCTL);

	cs.mult = clocksource_hz2mult(imx_get_gptclk(), cs.shift);

	init_clock(&cs);

	clock_register_client(&imx_clock_notifier);

	return 0;
}

static __maybe_unused struct of_device_id imx_gpt_dt_ids[] = {
	{
		.compatible = "fsl,imx1-gpt",
		.data = (unsigned long)&regs_imx1,
	}, {
		.compatible = "fsl,imx31-gpt",
		.data = (unsigned long)&regs_imx31,
	}, {
		/* sentinel */
	}
};

static struct platform_device_id imx_gpt_ids[] = {
	{
		.name = "imx1-gpt",
		.driver_data = (unsigned long)&regs_imx1,
	}, {
		.name = "imx31-gpt",
		.driver_data = (unsigned long)&regs_imx31,
	}, {
		/* sentinel */
	},
};

static struct driver_d imx_gpt_driver = {
	.name = "imx-gpt",
	.probe = imx_gpt_probe,
	.of_compatible = DRV_OF_COMPAT(imx_gpt_dt_ids),
	.id_table = imx_gpt_ids,
};

static int imx_gpt_init(void)
{
	return platform_driver_register(&imx_gpt_driver);
}
coredevice_initcall(imx_gpt_init);

/*
 * Watchdog Registers
 */
#ifdef CONFIG_ARCH_IMX1
#define WDOG_WCR	0x00 /* Watchdog Control Register */
#define WDOG_WSR	0x04 /* Watchdog Service Register */
#define WDOG_WSTR	0x08 /* Watchdog Status Register  */
#define WDOG_WCR_WDE	(1 << 0)
#else
#define WDOG_WCR	0x00 /* Watchdog Control Register */
#define WDOG_WSR	0x02 /* Watchdog Service Register */
#define WDOG_WSTR	0x04 /* Watchdog Status Register  */
#define WDOG_WCR_WDE	(1 << 2)
#endif

/*
 * Reset the cpu by setting up the watchdog timer and let it time out
 */
void __noreturn reset_cpu (unsigned long addr)
{
	void __iomem *wdt = IOMEM(IMX_WDT_BASE);

	/* Disable watchdog and set Time-Out field to 0 */
	writew(0x0, wdt + WDOG_WCR);

	/* Write Service Sequence */
	writew(0x5555, wdt + WDOG_WSR);
	writew(0xaaaa, wdt + WDOG_WSR);

	/* Enable watchdog */
	writew(WDOG_WCR_WDE, wdt + WDOG_WCR);

	while (1);
	/*NOTREACHED*/
}
EXPORT_SYMBOL(reset_cpu);