DM8168: EIO when adding an I2C regulator

Hi, 

I get a EIO which is thrown inside tps53819a_probe when trying to register a i2c regulator. It seems like the exception is because of lacking platform_data.

Basically what I did is casting the default gpio-regulator registration into the i2c regulator's, and add some driver support for the i2c regulator.

1. Add regulator specific data to the board file at "arch/arm/mach-omap2/board-dm8168z3.c":

#elif CONFIG_REGULATOR_TPS53819A
static struct regulator_consumer_supply ti816x_tps53819a_dcdc_supply[] = {
	{
		.supply = "tps53819a",
	},
};

static struct regulator_init_data tps53819a_pmic_init_data = {
	.constraints = {
		.min_uV		= 800000,
		.max_uV		= 1500000,
		.valid_ops_mask	= (REGULATOR_CHANGE_VOLTAGE |
			REGULATOR_CHANGE_STATUS),
	},
	.num_consumer_supplies	= ARRAY_SIZE(ti816x_tps53819a_dcdc_supply),
	.consumer_supplies	= ti816x_tps53819a_dcdc_supply,
};

/* TPS regulator platform data */
static struct tps53819a_reg_platform_data tps53819a_vr_init_data = {
	.name			= "tps53819a",
	.pmic_init_data		= &tps53819a_pmic_init_data,
};

/* VCORE for SR regulator init */
static struct platform_device ti816x_tps53819a_vr_device = {
	.name	= "tps53819a",
	.id		= -1,
	.dev    = {
		      .platform_data = &tps53819a_vr_init_data,
	},
};

static void __init ti816x_tps53819a_vr_init(void)
{
	if (platform_device_register(&ti816x_tps53819a_vr_device))
		printk(KERN_ERR "failed to register ti816x_tps53819a_vr device\n");
        else
		printk(KERN_INFO "registered ti816x_tps53819a_vr device\n");
}
.... 

static struct i2c_board_info __initdata z3dm816x_i2c_boardinfo1[] = {
        {
                I2C_BOARD_INFO("tps53819a", 0x2a),
                .platform_data = &tps53819a_vr_init_data,
        },
};
...

#ifdef CONFIG_REGULATOR_TPS53819A
        ti816x_tps53819a_vr_init();

2. Add SR platform specific data based on the chosen PMIC to the devices file at "arch/arm/mach-omap2/devices.c":

static struct ti816x_sr_platform_data ti816x_sr_pdata = {
	.vd_name		= "tps53819a",
	.ip_type		= 2,
	.irq_delay		= 2000,
	.no_of_vds		= 1,
	.no_of_sens		= ARRAY_SIZE(sr_sensor_data),
        .vstep_size_uv          = 49000,
	.enable_on_init		= true,
	.sr_sdata		= sr_sensor_data,
};

3. Add regulator driver support at "kernel/driver/regulator/tps53819a-regulator.c":

static int __devinit tps53819a_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
    const struct tps_info *info = (void *)id->driver_data;
    struct regulator_init_data *init_data;
    struct regulator_dev *rdev;
    struct tps_pmic *tps;
    int error;

    if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
        dev_err(&client->dev, "i2c_check_functionality failed!\n");
        return -EIO;
    }

    init_data = client->dev.platform_data;
    if (!init_data) {
        dev_err(&client->dev, "platform_data is null!\n");
    	return -EIO;
    }

    tps = kzalloc(sizeof(*tps), GFP_KERNEL);
    if (!tps)
    	return -ENOMEM;

    mutex_init(&tps->io_lock);

    /* common for all regulators */
    tps->client = client;
    tps->info = info;
    tps->desc.name = info->name;
    tps->desc.n_voltages = ARRAY_SIZE(VDCDC_VSEL_table);
    tps->desc.ops = &tps53819a_dcdc_ops;
    tps->desc.type = REGULATOR_VOLTAGE;
    tps->desc.owner = THIS_MODULE;

    /* Register the Regulator */
    rdev = regulator_register(&tps->desc, &client->dev, init_data, tps);
    if (IS_ERR(rdev)) {
        dev_err(&client->dev, "failed to register %s\n", id->name);
        error = PTR_ERR(rdev);
        goto exit_devreg;
    }

    /* Save regulator for cleanup */
    tps->rdev = rdev;

    i2c_set_clientdata(client, tps);

    return 0;

exit_devreg:
    regulator_unregister(tps->rdev);

    kfree(tps);
    return error;
}

static const struct tps_info tps53819a_regs[] = {
    {
        .name = "TPS53819A_VDCDC",
        .min_uV = TPS53819A_MIN_VOLTAGE,
        .max_uV = TPS53819A_MAX_VOLTAGE,
        .table_len = ARRAY_SIZE(VDCDC_VSEL_table),
        .table = VDCDC_VSEL_table,
    },
};

static const struct i2c_device_id tps53819a_id[] = {
    {
        .name = "tps53819a",
        .driver_data = (unsigned long) tps53819a_regs,
    },
};

MODULE_DEVICE_TABLE(i2c, tps53819a_id);

static struct i2c_driver tps53819a_i2c_driver = {
    .driver = {
        .name = "tps53819a",
        .owner = THIS_MODULE,
    },
    .probe = tps53819a_probe,
    .remove = __devexit_p(tps53819a_remove),
    .id_table = tps53819a_id,
};

static int __init tps53819a_init(void)
{
    printk(KERN_INFO "regulator: %s\n", __func__);
    return i2c_add_driver(&tps53819a_i2c_driver);
}
module_init(tps53819a_init);

Thanks,

Guang