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>
10#include <linux/io.h>
11#include <asm/proc-fns.h>
12#include <asm/system_misc.h>
13
14#include <mach/regs-ost.h>
15#include <mach/reset.h>
16#include <mach/smemc.h>
17
18unsigned int reset_status;
19EXPORT_SYMBOL(reset_status);
20
21static void do_hw_reset(void);
22
23static int reset_gpio = -1;
24
25int init_gpio_reset(int gpio, int output, int level)
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
35	if (output)
36		rc = gpio_direction_output(gpio, level);
37	else
38		rc = gpio_direction_input(gpio);
39	if (rc) {
40		printk(KERN_ERR "Can't configure reset_gpio\n");
41		gpio_free(gpio);
42		goto out;
43	}
44
45out:
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 */
57static 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
78static void do_hw_reset(void)
79{
80	/* Initialize the watchdog and let it fire */
81	writel_relaxed(OWER_WME, OWER);
82	writel_relaxed(OSSR_M3, OSSR);
83	/* ... in 100 ms */
84	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
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);
91}
92
93void pxa_restart(enum reboot_mode mode, const char *cmd)
94{
95	local_irq_disable();
96	local_fiq_disable();
97
98	clear_reset_status(RESET_STATUS_ALL);
99
100	switch (mode) {
101	case REBOOT_SOFT:
102		/* Jump into ROM at address 0 */
103		soft_restart(0);
104		break;
105	case REBOOT_GPIO:
106		do_gpio_reset();
107		break;
108	case REBOOT_HARD:
109	default:
110		do_hw_reset();
111		break;
112	}
113}
114