[mirror_ubuntu-artful-kernel.git] / arch / arm / mach-pxa / reset.c

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <asm/proc-fns.h>
#include <asm/system_misc.h>

#include <mach/regs-ost.h>
#include <mach/reset.h>
#include <mach/smemc.h>

unsigned int reset_status;
EXPORT_SYMBOL(reset_status);

static void do_hw_reset(void);

static int reset_gpio = -1;

int init_gpio_reset(int gpio, int output, int level)
{
	int rc;

	rc = gpio_request(gpio, "reset generator");
	if (rc) {
		printk(KERN_ERR "Can't request reset_gpio\n");
		goto out;
	}

	if (output)
		rc = gpio_direction_output(gpio, level);
	else
		rc = gpio_direction_input(gpio);
	if (rc) {
		printk(KERN_ERR "Can't configure reset_gpio\n");
		gpio_free(gpio);
		goto out;
	}

out:
	if (!rc)
		reset_gpio = gpio;

	return rc;
}

/*
 * Trigger GPIO reset.
 * This covers various types of logic connecting gpio pin
 * to RESET pins (nRESET or GPIO_RESET):
 */
static void do_gpio_reset(void)
{
	BUG_ON(reset_gpio == -1);

	/* drive it low */
	gpio_direction_output(reset_gpio, 0);
	mdelay(2);
	/* rising edge or drive high */
	gpio_set_value(reset_gpio, 1);
	mdelay(2);
	/* falling edge */
	gpio_set_value(reset_gpio, 0);

	/* give it some time */
	mdelay(10);

	WARN_ON(1);
	/* fallback */
	do_hw_reset();
}

static void do_hw_reset(void)
{
	/* Initialize the watchdog and let it fire */
	writel_relaxed(OWER_WME, OWER);
	writel_relaxed(OSSR_M3, OSSR);
	/* ... in 100 ms */
	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
	/*
	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
	 * we put SDRAM into self-refresh to prevent that
	 */
	while (1)
		writel_relaxed(MDREFR_SLFRSH, MDREFR);
}

void pxa_restart(enum reboot_mode mode, const char *cmd)
{
	local_irq_disable();
	local_fiq_disable();

	clear_reset_status(RESET_STATUS_ALL);

	switch (mode) {
	case REBOOT_SOFT:
		/* Jump into ROM at address 0 */
		soft_restart(0);
		break;
	case REBOOT_GPIO:
		do_gpio_reset();
		break;
	case REBOOT_HARD:
	default:
		do_hw_reset();
		break;
	}
}
Commit	Line	Data
75f10b46 DES	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License version 2 as
	4	* published by the Free Software Foundation.
	5	*/
	6	#include <linux/kernel.h>
	7	#include <linux/module.h>
	8	#include <linux/delay.h>
	9	#include <linux/gpio.h>
fced80c7	10	#include <linux/io.h>
75f10b46	11	#include <asm/proc-fns.h>
9f97da78	12	#include <asm/system_misc.h>
75f10b46	13
5bf3df3f	14	#include <mach/regs-ost.h>
afd2fc02	15	#include <mach/reset.h>
ff88b472	16	#include <mach/smemc.h>
75f10b46	17
04fef228 EM	18	unsigned int reset_status;
04fef228 EM	19	EXPORT_SYMBOL(reset_status);
75f10b46 DES	20
	21	static void do_hw_reset(void);
	22
	23	static int reset_gpio = -1;
	24
216e3b7a	25	int init_gpio_reset(int gpio, int output, int level)
75f10b46 DES	26	{
	27	int rc;
	28
	29	rc = gpio_request(gpio, "reset generator");
	30	if (rc) {
	31	printk(KERN_ERR "Can't request reset_gpio\n");
	32	goto out;
	33	}
	34
69fc7eed	35	if (output)
216e3b7a	36	rc = gpio_direction_output(gpio, level);
69fc7eed DES	37	else
69fc7eed DES	38	rc = gpio_direction_input(gpio);
75f10b46	39	if (rc) {
69fc7eed	40	printk(KERN_ERR "Can't configure reset_gpio\n");
75f10b46 DES	41	gpio_free(gpio);
	42	goto out;
	43	}
	44
	45	out:
	46	if (!rc)
	47	reset_gpio = gpio;
	48
	49	return rc;
	50	}
	51
	52	/*
	53	* Trigger GPIO reset.
	54	* This covers various types of logic connecting gpio pin
	55	* to RESET pins (nRESET or GPIO_RESET):
	56	*/
	57	static void do_gpio_reset(void)
	58	{
	59	BUG_ON(reset_gpio == -1);
	60
	61	/* drive it low */
	62	gpio_direction_output(reset_gpio, 0);
	63	mdelay(2);
	64	/* rising edge or drive high */
	65	gpio_set_value(reset_gpio, 1);
	66	mdelay(2);
	67	/* falling edge */
	68	gpio_set_value(reset_gpio, 0);
	69
	70	/* give it some time */
	71	mdelay(10);
	72
	73	WARN_ON(1);
	74	/* fallback */
	75	do_hw_reset();
	76	}
	77
	78	static void do_hw_reset(void)
	79	{
	80	/* Initialize the watchdog and let it fire */
3169663a RK	81	writel_relaxed(OWER_WME, OWER);
	82	writel_relaxed(OSSR_M3, OSSR);
	83	/* ... in 100 ms */
	84	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
ff88b472 SI	85	/*
	86	* SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
	87	* we put SDRAM into self-refresh to prevent that
	88	*/
	89	while (1)
	90	writel_relaxed(MDREFR_SLFRSH, MDREFR);
75f10b46 DES	91	}
75f10b46 DES	92
7b6d864b	93	void pxa_restart(enum reboot_mode mode, const char *cmd)
75f10b46	94	{
271a74fc RK	95	local_irq_disable();
	96	local_fiq_disable();
	97
04fef228	98	clear_reset_status(RESET_STATUS_ALL);
75f10b46 DES	99
75f10b46 DES	100	switch (mode) {
7b6d864b	101	case REBOOT_SOFT:
75f10b46	102	/* Jump into ROM at address 0 */
e879c862	103	soft_restart(0);
75f10b46	104	break;
7b6d864b	105	case REBOOT_GPIO:
75f10b46 DES	106	do_gpio_reset();
75f10b46 DES	107	break;
7b6d864b	108	case REBOOT_HARD:
28105fda JK	109	default:
	110	do_hw_reset();
	111	break;
75f10b46 DES	112	}
75f10b46 DES	113	}