1 /*
2  *
3  * Utility functions for the Freescale MPC52xx.
4  *
5  * Copyright (C) 2006 Sylvain Munaut <tnt@246tNt.com>
6  *
7  * This file is licensed under the terms of the GNU General Public License
8  * version 2. This program is licensed "as is" without any warranty of any
9  * kind, whether express or implied.
10  *
11  */
12 
13 #undef DEBUG
14 
15 #include <linux/kernel.h>
16 
17 #include <asm/io.h>
18 #include <asm/prom.h>
19 #include <asm/of_platform.h>
20 #include <asm/mpc52xx.h>
21 
22 
23 void __iomem *
24 mpc52xx_find_and_map(const char *compatible)
25 {
26 	struct device_node *ofn;
27 	const u32 *regaddr_p;
28 	u64 regaddr64, size64;
29 
30 	ofn = of_find_compatible_node(NULL, NULL, compatible);
31 	if (!ofn)
32 		return NULL;
33 
34 	regaddr_p = of_get_address(ofn, 0, &size64, NULL);
35 	if (!regaddr_p) {
36 		of_node_put(ofn);
37 		return NULL;
38 	}
39 
40 	regaddr64 = of_translate_address(ofn, regaddr_p);
41 
42 	of_node_put(ofn);
43 
44 	return ioremap((u32)regaddr64, (u32)size64);
45 }
46 EXPORT_SYMBOL(mpc52xx_find_and_map);
47 
48 
49 /**
50  * 	mpc52xx_find_ipb_freq - Find the IPB bus frequency for a device
51  * 	@node:	device node
52  *
53  * 	Returns IPB bus frequency, or 0 if the bus frequency cannot be found.
54  */
55 unsigned int
56 mpc52xx_find_ipb_freq(struct device_node *node)
57 {
58 	struct device_node *np;
59 	const unsigned int *p_ipb_freq = NULL;
60 
61 	of_node_get(node);
62 	while (node) {
63 		p_ipb_freq = of_get_property(node, "bus-frequency", NULL);
64 		if (p_ipb_freq)
65 			break;
66 
67 		np = of_get_parent(node);
68 		of_node_put(node);
69 		node = np;
70 	}
71 	if (node)
72 		of_node_put(node);
73 
74 	return p_ipb_freq ? *p_ipb_freq : 0;
75 }
76 EXPORT_SYMBOL(mpc52xx_find_ipb_freq);
77 
78 
79 void __init
80 mpc52xx_setup_cpu(void)
81 {
82 	struct mpc52xx_cdm  __iomem *cdm;
83 	struct mpc52xx_xlb  __iomem *xlb;
84 
85 	/* Map zones */
86 	cdm = mpc52xx_find_and_map("mpc5200-cdm");
87 	xlb = mpc52xx_find_and_map("mpc5200-xlb");
88 
89 	if (!cdm || !xlb) {
90 		printk(KERN_ERR __FILE__ ": "
91 			"Error while mapping CDM/XLB during mpc52xx_setup_cpu. "
92 			"Expect some abnormal behavior\n");
93 		goto unmap_regs;
94 	}
95 
96 	/* Use internal 48 Mhz */
97 	out_8(&cdm->ext_48mhz_en, 0x00);
98 	out_8(&cdm->fd_enable, 0x01);
99 	if (in_be32(&cdm->rstcfg) & 0x40)	/* Assumes 33Mhz clock */
100 		out_be16(&cdm->fd_counters, 0x0001);
101 	else
102 		out_be16(&cdm->fd_counters, 0x5555);
103 
104 	/* Configure the XLB Arbiter priorities */
105 	out_be32(&xlb->master_pri_enable, 0xff);
106 	out_be32(&xlb->master_priority, 0x11111111);
107 
108 	/* Disable XLB pipelining */
109 	/* (cfr errate 292. We could do this only just before ATA PIO
110 	    transaction and re-enable it afterwards ...) */
111 	out_be32(&xlb->config, in_be32(&xlb->config) | MPC52xx_XLB_CFG_PLDIS);
112 
113 	/* Unmap zones */
114 unmap_regs:
115 	if (cdm) iounmap(cdm);
116 	if (xlb) iounmap(xlb);
117 }
118 
119 void __init
120 mpc52xx_declare_of_platform_devices(void)
121 {
122 	/* Find every child of the SOC node and add it to of_platform */
123 	if (of_platform_bus_probe(NULL, NULL, NULL))
124 		printk(KERN_ERR __FILE__ ": "
125 			"Error while probing of_platform bus\n");
126 }
127 
128