2 * PowerNV LPC bus handling.
4 * Copyright 2013 IBM Corp.
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.
12 #include <linux/kernel.h>
14 #include <linux/bug.h>
15 #include <linux/gfp.h>
16 #include <linux/slab.h>
18 #include <asm/machdep.h>
19 #include <asm/firmware.h>
24 * We could probably fit that inside the scom_map_t
25 * which is a void* after all but it's really too ugly
26 * so let's kmalloc it for now
28 struct opal_scom_map {
33 static scom_map_t opal_scom_map(struct device_node *dev, u64 reg, u64 count)
35 struct opal_scom_map *m;
38 if (!of_get_property(dev, "scom-controller", NULL)) {
39 pr_err("%s: device %s is not a SCOM controller\n",
40 __func__, dev->full_name);
41 return SCOM_MAP_INVALID;
43 gcid = of_get_property(dev, "ibm,chip-id", NULL);
45 pr_err("%s: device %s has no ibm,chip-id\n",
46 __func__, dev->full_name);
47 return SCOM_MAP_INVALID;
49 m = kmalloc(sizeof(struct opal_scom_map), GFP_KERNEL);
52 m->chip = be32_to_cpup(gcid);
58 static void opal_scom_unmap(scom_map_t map)
63 static int opal_xscom_err_xlate(int64_t rc)
68 /* Add more translations if necessary */
74 static int opal_scom_read(scom_map_t map, u32 reg, u64 *value)
76 struct opal_scom_map *m = map;
79 rc = opal_xscom_read(m->chip, m->addr + reg, (uint64_t *)__pa(value));
80 return opal_xscom_err_xlate(rc);
83 static int opal_scom_write(scom_map_t map, u32 reg, u64 value)
85 struct opal_scom_map *m = map;
88 rc = opal_xscom_write(m->chip, m->addr + reg, value);
89 return opal_xscom_err_xlate(rc);
92 static const struct scom_controller opal_scom_controller = {
94 .unmap = opal_scom_unmap,
95 .read = opal_scom_read,
96 .write = opal_scom_write
99 static int opal_xscom_init(void)
101 if (firmware_has_feature(FW_FEATURE_OPALv3))
102 scom_init(&opal_scom_controller);
105 arch_initcall(opal_xscom_init);