board-mop500-uib.c

Go to the documentation of this file.

/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Rabin Vincent <[email protected]> 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;
}