mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-26 14:14:01 +08:00
106 lines
2.3 KiB
C
106 lines
2.3 KiB
C
|
/*
|
||
|
|
* PowerNV LPC bus handling.
|
||
|
|
*
|
||
|
|
* Copyright 2013 IBM Corp.
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU General Public License
|
||
|
|
* as published by the Free Software Foundation; either version
|
||
|
|
* 2 of the License, or (at your option) any later version.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/of.h>
|
||
|
|
#include <linux/bug.h>
|
||
|
|
#include <linux/gfp.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
|
||
|
|
#include <asm/machdep.h>
|
||
|
|
#include <asm/firmware.h>
|
||
|
|
#include <asm/opal.h>
|
||
|
|
#include <asm/scom.h>
|
||
|
|
|
||
|
|
/*
|
||
|
|
* We could probably fit that inside the scom_map_t
|
||
|
|
* which is a void* after all but it's really too ugly
|
||
|
|
* so let's kmalloc it for now
|
||
|
|
*/
|
||
|
|
struct opal_scom_map {
|
||
|
|
uint32_t chip;
|
||
|
|
uint32_t addr;
|
||
|
|
};
|
||
|
|
|
||
|
|
static scom_map_t opal_scom_map(struct device_node *dev, u64 reg, u64 count)
|
||
|
|
{
|
||
|
|
struct opal_scom_map *m;
|
||
|
|
const __be32 *gcid;
|
||
|
|
|
||
|
|
if (!of_get_property(dev, "scom-controller", NULL)) {
|
||
|
|
pr_err("%s: device %s is not a SCOM controller\n",
|
||
|
|
__func__, dev->full_name);
|
||
|
|
return SCOM_MAP_INVALID;
|
||
|
|
}
|
||
|
|
gcid = of_get_property(dev, "ibm,chip-id", NULL);
|
||
|
|
if (!gcid) {
|
||
|
|
pr_err("%s: device %s has no ibm,chip-id\n",
|
||
|
|
__func__, dev->full_name);
|
||
|
|
return SCOM_MAP_INVALID;
|
||
|
|
}
|
||
|
|
m = kmalloc(sizeof(struct opal_scom_map), GFP_KERNEL);
|
||
|
|
if (!m)
|
||
|
|
return NULL;
|
||
|
|
m->chip = be32_to_cpup(gcid);
|
||
|
|
m->addr = reg;
|
||
|
|
|
||
|
|
return (scom_map_t)m;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void opal_scom_unmap(scom_map_t map)
|
||
|
|
{
|
||
|
|
kfree(map);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int opal_xscom_err_xlate(int64_t rc)
|
||
|
|
{
|
||
|
|
switch(rc) {
|
||
|
|
case 0:
|
||
|
|
return 0;
|
||
|
|
/* Add more translations if necessary */
|
||
|
|
default:
|
||
|
|
return -EIO;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static int opal_scom_read(scom_map_t map, u32 reg, u64 *value)
|
||
|
|
{
|
||
|
|
struct opal_scom_map *m = map;
|
||
|
|
int64_t rc;
|
||
|
|
|
||
|
|
rc = opal_xscom_read(m->chip, m->addr + reg, (uint64_t *)__pa(value));
|
||
|
|
return opal_xscom_err_xlate(rc);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int opal_scom_write(scom_map_t map, u32 reg, u64 value)
|
||
|
|
{
|
||
|
|
struct opal_scom_map *m = map;
|
||
|
|
int64_t rc;
|
||
|
|
|
||
|
|
rc = opal_xscom_write(m->chip, m->addr + reg, value);
|
||
|
|
return opal_xscom_err_xlate(rc);
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct scom_controller opal_scom_controller = {
|
||
|
|
.map = opal_scom_map,
|
||
|
|
.unmap = opal_scom_unmap,
|
||
|
|
.read = opal_scom_read,
|
||
|
|
.write = opal_scom_write
|
||
|
|
};
|
||
|
|
|
||
|
|
static int opal_xscom_init(void)
|
||
|
|
{
|
||
|
|
if (firmware_has_feature(FW_FEATURE_OPALv3))
|
||
|
|
scom_init(&opal_scom_controller);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
arch_initcall(opal_xscom_init);
|