static int fschmd_probe()

in fschmd.c [1083:1249]

• 129 lines of code
• 30 McCabe index (conditional complexity)

static int fschmd_probe(struct i2c_client *client)
{
	struct fschmd_data *data;
	const char * const names[7] = { "Poseidon", "Hermes", "Scylla",
				"Heracles", "Heimdall", "Hades", "Syleus" };
	const int watchdog_minors[] = { WATCHDOG_MINOR, 212, 213, 214, 215 };
	int i, err;
	enum chips kind = i2c_match_id(fschmd_id, client)->driver_data;

	data = kzalloc(sizeof(struct fschmd_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);
	mutex_init(&data->watchdog_lock);
	INIT_LIST_HEAD(&data->list);
	kref_init(&data->kref);
	/*
	 * Store client pointer in our data struct for watchdog usage
	 * (where the client is found through a data ptr instead of the
	 * otherway around)
	 */
	data->client = client;
	data->kind = kind;

	if (kind == fscpos) {
		/*
		 * The Poseidon has hardwired temp limits, fill these
		 * in for the alarm resetting code
		 */
		data->temp_max[0] = 70 + 128;
		data->temp_max[1] = 50 + 128;
		data->temp_max[2] = 50 + 128;
	}

	/* Read the special DMI table for fscher and newer chips */
	if ((kind == fscher || kind >= fschrc) && dmi_vref == -1) {
		dmi_walk(fschmd_dmi_decode, NULL);
		if (dmi_vref == -1) {
			dev_warn(&client->dev,
				"Couldn't get voltage scaling factors from "
				"BIOS DMI table, using builtin defaults\n");
			dmi_vref = 33;
		}
	}

	/* Read in some never changing registers */
	data->revision = i2c_smbus_read_byte_data(client, FSCHMD_REG_REVISION);
	data->global_control = i2c_smbus_read_byte_data(client,
					FSCHMD_REG_CONTROL);
	data->watchdog_control = i2c_smbus_read_byte_data(client,
					FSCHMD_REG_WDOG_CONTROL[data->kind]);
	data->watchdog_state = i2c_smbus_read_byte_data(client,
					FSCHMD_REG_WDOG_STATE[data->kind]);
	data->watchdog_preset = i2c_smbus_read_byte_data(client,
					FSCHMD_REG_WDOG_PRESET[data->kind]);

	err = device_create_file(&client->dev, &dev_attr_alert_led);
	if (err)
		goto exit_detach;

	for (i = 0; i < FSCHMD_NO_VOLT_SENSORS[data->kind]; i++) {
		err = device_create_file(&client->dev,
					&fschmd_attr[i].dev_attr);
		if (err)
			goto exit_detach;
	}

	for (i = 0; i < (FSCHMD_NO_TEMP_SENSORS[data->kind] * 4); i++) {
		/* Poseidon doesn't have TEMP_LIMIT registers */
		if (kind == fscpos && fschmd_temp_attr[i].dev_attr.show ==
				temp_max_show)
			continue;

		if (kind == fscsyl) {
			if (i % 4 == 0)
				data->temp_status[i / 4] =
					i2c_smbus_read_byte_data(client,
						FSCHMD_REG_TEMP_STATE
						[data->kind][i / 4]);
			if (data->temp_status[i / 4] & FSCHMD_TEMP_DISABLED)
				continue;
		}

		err = device_create_file(&client->dev,
					&fschmd_temp_attr[i].dev_attr);
		if (err)
			goto exit_detach;
	}

	for (i = 0; i < (FSCHMD_NO_FAN_SENSORS[data->kind] * 5); i++) {
		/* Poseidon doesn't have a FAN_MIN register for its 3rd fan */
		if (kind == fscpos &&
				!strcmp(fschmd_fan_attr[i].dev_attr.attr.name,
					"pwm3_auto_point1_pwm"))
			continue;

		if (kind == fscsyl) {
			if (i % 5 == 0)
				data->fan_status[i / 5] =
					i2c_smbus_read_byte_data(client,
						FSCHMD_REG_FAN_STATE
						[data->kind][i / 5]);
			if (data->fan_status[i / 5] & FSCHMD_FAN_DISABLED)
				continue;
		}

		err = device_create_file(&client->dev,
					&fschmd_fan_attr[i].dev_attr);
		if (err)
			goto exit_detach;
	}

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		data->hwmon_dev = NULL;
		goto exit_detach;
	}

	/*
	 * We take the data_mutex lock early so that watchdog_open() cannot
	 * run when misc_register() has completed, but we've not yet added
	 * our data to the watchdog_data_list (and set the default timeout)
	 */
	mutex_lock(&watchdog_data_mutex);
	for (i = 0; i < ARRAY_SIZE(watchdog_minors); i++) {
		/* Register our watchdog part */
		snprintf(data->watchdog_name, sizeof(data->watchdog_name),
			"watchdog%c", (i == 0) ? '\0' : ('0' + i));
		data->watchdog_miscdev.name = data->watchdog_name;
		data->watchdog_miscdev.fops = &watchdog_fops;
		data->watchdog_miscdev.minor = watchdog_minors[i];
		err = misc_register(&data->watchdog_miscdev);
		if (err == -EBUSY)
			continue;
		if (err) {
			data->watchdog_miscdev.minor = 0;
			dev_err(&client->dev,
				"Registering watchdog chardev: %d\n", err);
			break;
		}

		list_add(&data->list, &watchdog_data_list);
		watchdog_set_timeout(data, 60);
		dev_info(&client->dev,
			"Registered watchdog chardev major 10, minor: %d\n",
			watchdog_minors[i]);
		break;
	}
	if (i == ARRAY_SIZE(watchdog_minors)) {
		data->watchdog_miscdev.minor = 0;
		dev_warn(&client->dev,
			 "Couldn't register watchdog chardev (due to no free minor)\n");
	}
	mutex_unlock(&watchdog_data_mutex);

	dev_info(&client->dev, "Detected FSC %s chip, revision: %d\n",
		names[data->kind], (int) data->revision);

	return 0;

exit_detach:
	fschmd_remove(client); /* will also free data for us */
	return err;
}