OpenCloudOS-Kernel/arch/arm/mach-ux500/board-mop500-uib.c

134 lines
2.5 KiB
C

/*
* Copyright (C) ST-Ericsson SA 2010
*
* Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
* License terms: GNU General Public License (GPL), version 2
*/
#define pr_fmt(fmt) "mop500-uib: " fmt
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include "board-mop500.h"
#include "id.h"
enum mop500_uib {
STUIB,
U8500UIB,
};
struct uib {
const char *name;
const char *option;
void (*init)(void);
};
static struct uib __initdata mop500_uibs[] = {
[STUIB] = {
.name = "ST-UIB",
.option = "stuib",
.init = mop500_stuib_init,
},
[U8500UIB] = {
.name = "U8500-UIB",
.option = "u8500uib",
.init = mop500_u8500uib_init,
},
};
static struct uib *mop500_uib;
static int __init mop500_uib_setup(char *str)
{
int i;
for (i = 0; i < ARRAY_SIZE(mop500_uibs); i++) {
struct uib *uib = &mop500_uibs[i];
if (!strcmp(str, uib->option)) {
mop500_uib = uib;
break;
}
}
if (i == ARRAY_SIZE(mop500_uibs))
pr_err("invalid uib= option (%s)\n", str);
return 1;
}
__setup("uib=", mop500_uib_setup);
/*
* The UIBs are detected after the I2C host controllers are registered, so
* i2c_register_board_info() can't be used.
*/
void mop500_uib_i2c_add(int busnum, struct i2c_board_info *info,
unsigned n)
{
struct i2c_adapter *adap;
struct i2c_client *client;
int i;
adap = i2c_get_adapter(busnum);
if (!adap) {
pr_err("failed to get adapter i2c%d\n", busnum);
return;
}
for (i = 0; i < n; i++) {
client = i2c_new_device(adap, &info[i]);
if (!client)
pr_err("failed to register %s to i2c%d\n",
info[i].type, busnum);
}
i2c_put_adapter(adap);
}
static void __init __mop500_uib_init(struct uib *uib, const char *why)
{
pr_info("%s (%s)\n", uib->name, why);
uib->init();
}
/*
* Detect the UIB attached based on the presence or absence of i2c devices.
*/
int __init mop500_uib_init(void)
{
struct uib *uib = mop500_uib;
struct i2c_adapter *i2c0;
int ret;
if (!cpu_is_u8500_family())
return -ENODEV;
if (uib) {
__mop500_uib_init(uib, "from uib= boot argument");
return 0;
}
i2c0 = i2c_get_adapter(0);
if (!i2c0) {
__mop500_uib_init(&mop500_uibs[STUIB],
"fallback, could not get i2c0");
return -ENODEV;
}
/* U8500-UIB has the TC35893 at 0x44 on I2C0, the ST-UIB doesn't. */
ret = i2c_smbus_xfer(i2c0, 0x44, 0, I2C_SMBUS_WRITE, 0,
I2C_SMBUS_QUICK, NULL);
i2c_put_adapter(i2c0);
if (ret == 0)
uib = &mop500_uibs[U8500UIB];
else
uib = &mop500_uibs[STUIB];
__mop500_uib_init(uib, "detected");
return 0;
}