linux/arch/arm/mach-ux500/board-mop500-uib.c
Lee Jones fd6948bb2a ARM: ux500: Only initialise STE's UIBs on boards which support them
ST-Ericsson uses User Interface Boards to extend functionality of
some of their development boards. However, these aren't compatible
with all the supported boards found in Mainline (Snowball for
instance). This patch ensures that the UIBs are only probed on
boards which can actually support them. This in turn saves lots of
unnecessary error messages normally found in Snowball's boot log.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-06-01 02:04:33 +02:00

133 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 <mach/hardware.h>
#include "board-mop500.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;
}