1 /*
2 * SCOM backend for WSP
3 *
4 * Copyright 2010 Benjamin Herrenschmidt, IBM Corp.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <linux/cpumask.h>
13 #include <linux/io.h>
14 #include <linux/of.h>
15 #include <linux/spinlock.h>
16 #include <linux/types.h>
17
18 #include <asm/cputhreads.h>
19 #include <asm/reg_a2.h>
20 #include <asm/scom.h>
21 #include <asm/udbg.h>
22
23 #include "wsp.h"
24
25
wsp_scom_map(struct device_node * dev,u64 reg,u64 count)26 static scom_map_t wsp_scom_map(struct device_node *dev, u64 reg, u64 count)
27 {
28 struct resource r;
29 u64 xscom_addr;
30
31 if (!of_get_property(dev, "scom-controller", NULL)) {
32 pr_err("%s: device %s is not a SCOM controller\n",
33 __func__, dev->full_name);
34 return SCOM_MAP_INVALID;
35 }
36
37 if (of_address_to_resource(dev, 0, &r)) {
38 pr_debug("Failed to find SCOM controller address\n");
39 return 0;
40 }
41
42 /* Transform the SCOM address into an XSCOM offset */
43 xscom_addr = ((reg & 0x7f000000) >> 1) | ((reg & 0xfffff) << 3);
44
45 return (scom_map_t)ioremap(r.start + xscom_addr, count << 3);
46 }
47
wsp_scom_unmap(scom_map_t map)48 static void wsp_scom_unmap(scom_map_t map)
49 {
50 iounmap((void *)map);
51 }
52
wsp_scom_read(scom_map_t map,u32 reg)53 static u64 wsp_scom_read(scom_map_t map, u32 reg)
54 {
55 u64 __iomem *addr = (u64 __iomem *)map;
56
57 return in_be64(addr + reg);
58 }
59
wsp_scom_write(scom_map_t map,u32 reg,u64 value)60 static void wsp_scom_write(scom_map_t map, u32 reg, u64 value)
61 {
62 u64 __iomem *addr = (u64 __iomem *)map;
63
64 return out_be64(addr + reg, value);
65 }
66
67 static const struct scom_controller wsp_scom_controller = {
68 .map = wsp_scom_map,
69 .unmap = wsp_scom_unmap,
70 .read = wsp_scom_read,
71 .write = wsp_scom_write
72 };
73
scom_init_wsp(void)74 void scom_init_wsp(void)
75 {
76 scom_init(&wsp_scom_controller);
77 }
78