aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/52xx/mpc52xx_common.c
blob: 9850685c542999c69a89ee65c94cba2b750e7b5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/*
 *
 * Utility functions for the Freescale MPC52xx.
 *
 * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 *
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/of_platform.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/mpc52xx.h>

/*
 * This variable is mapped in mpc52xx_map_wdt() and used in mpc52xx_restart().
 * Permanent mapping is required because mpc52xx_restart() can be called
 * from interrupt context while node mapping (which calls ioremap())
 * cannot be used at such point.
 */
static volatile struct mpc52xx_gpt *mpc52xx_wdt = NULL;

static void __iomem *
mpc52xx_map_node(struct device_node *ofn)
{
	const u32 *regaddr_p;
	u64 regaddr64, size64;

	if (!ofn)
		return NULL;

	regaddr_p = of_get_address(ofn, 0, &size64, NULL);
	if (!regaddr_p) {
		of_node_put(ofn);
		return NULL;
	}

	regaddr64 = of_translate_address(ofn, regaddr_p);

	of_node_put(ofn);

	return ioremap((u32)regaddr64, (u32)size64);
}

void __iomem *
mpc52xx_find_and_map(const char *compatible)
{
	return mpc52xx_map_node(
		of_find_compatible_node(NULL, NULL, compatible));
}

EXPORT_SYMBOL(mpc52xx_find_and_map);

void __iomem *
mpc52xx_find_and_map_path(const char *path)
{
	return mpc52xx_map_node(of_find_node_by_path(path));
}

EXPORT_SYMBOL(mpc52xx_find_and_map_path);

/**
 * 	mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
 * 	@node:	device node
 *
 * 	Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
 */
unsigned int
mpc52xx_find_ipb_freq(struct device_node *node)
{
	struct device_node *np;
	const unsigned int *p_ipb_freq = NULL;

	of_node_get(node);
	while (node) {
		p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
		if (p_ipb_freq)
			break;

		np = of_get_parent(node);
		of_node_put(node);
		node = np;
	}
	if (node)
		of_node_put(node);

	return p_ipb_freq ? *p_ipb_freq : 0;
}
EXPORT_SYMBOL(mpc52xx_find_ipb_freq);


/*
 * Configure the XLB arbiter settings to match what Linux expects.
 */
void __init
mpc5200_setup_xlb_arbiter(void)
{
	struct mpc52xx_xlb  __iomem *xlb;

	xlb = mpc52xx_find_and_map("mpc5200-xlb");
	if (!xlb) {
		printk(KERN_ERR __FILE__ ": "
			"Error mapping XLB in mpc52xx_setup_cpu().  "
			"Expect some abnormal behavior\n");
		return;
	}

	/* Configure the XLB Arbiter priorities */
	out_be32(&xlb->master_pri_enable, 0xff);
	out_be32(&xlb->master_priority, 0x11111111);

	/* Disable XLB pipelining
	 * (cfr errate 292. We could do this only just before ATA PIO
	 *  transaction and re-enable it afterwards ...)
	 */
	out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);

	iounmap(xlb);
}

void __init
mpc52xx_declare_of_platform_devices(void)
{
	/* Find every child of the SOC node and add it to of_platform */
	if (of_platform_bus_probe(NULL, NULL, NULL))
		printk(KERN_ERR __FILE__ ": "
			"Error while probing of_platform bus\n");
}

void __init
mpc52xx_map_wdt(void)
{
	const void *has_wdt;
	struct device_node *np;

	/* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
	 * possibly from a interrupt context. wdt is only implement
	 * on a gpt0, so check has-wdt property before mapping.
	 */
	for_each_compatible_node(np, NULL, "fsl,mpc5200-gpt") {
		has_wdt = of_get_property(np, "fsl,has-wdt", NULL);
		if (has_wdt) {
			mpc52xx_wdt = mpc52xx_map_node(np);
			return;
		}
	}
	for_each_compatible_node(np, NULL, "mpc5200-gpt") {
		has_wdt = of_get_property(np, "has-wdt", NULL);
		if (has_wdt) {
			mpc52xx_wdt = mpc52xx_map_node(np);
			return;
		}
	}
}

void
mpc52xx_restart(char *cmd)
{
	local_irq_disable();

	/* Turn on the watchdog and wait for it to expire.
	 * It effectively does a reset. */
	if (mpc52xx_wdt) {
		out_be32(&mpc52xx_wdt->mode, 0x00000000);
		out_be32(&mpc52xx_wdt->count, 0x000000ff);
		out_be32(&mpc52xx_wdt->mode, 0x00009004);
	} else
		printk("mpc52xx_restart: Can't access wdt. "
			"Restart impossible, system halted.\n");

	while (1);
}