adm1025.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

	struct adm1025_data *data = adm1025_update_device(dev);
	return sprintf(buf, "%u\n", data->vrm);
}
static ssize_t set_vrm(struct device *dev, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct adm1025_data *data = i2c_get_clientdata(client);
	data->vrm = simple_strtoul(buf, NULL, 10);
	return count;
}
static DEVICE_ATTR(vrm, S_IRUGO | S_IWUSR, show_vrm, set_vrm);

/*
 * Real code
 */

static int adm1025_attach_adapter(struct i2c_adapter *adapter)
{
	if (!(adapter->class & I2C_CLASS_HWMON))
		return 0;
	return i2c_detect(adapter, &addr_data, adm1025_detect);
}

/*
 * The following function does more than just detection. If detection
 * succeeds, it also registers the new chip.
 */
static int adm1025_detect(struct i2c_adapter *adapter, int address, int kind)
{
	struct i2c_client *new_client;
	struct adm1025_data *data;
	int err = 0;
	const char *name = "";
	u8 config;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		goto exit;

	if (!(data = kmalloc(sizeof(struct adm1025_data), GFP_KERNEL))) {
		err = -ENOMEM;
		goto exit;
	}
	memset(data, 0, sizeof(struct adm1025_data));

	/* The common I2C client data is placed right before the
	   ADM1025-specific data. */
	new_client = &data->client;
	i2c_set_clientdata(new_client, data);
	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &adm1025_driver;
	new_client->flags = 0;

	/*
	 * Now we do the remaining detection. A negative kind means that
	 * the driver was loaded with no force parameter (default), so we
	 * must both detect and identify the chip. A zero kind means that
	 * the driver was loaded with the force parameter, the detection
	 * step shall be skipped. A positive kind means that the driver
	 * was loaded with the force parameter and a given kind of chip is
	 * requested, so both the detection and the identification steps
	 * are skipped.
	 */
	config = i2c_smbus_read_byte_data(new_client, ADM1025_REG_CONFIG);
	if (kind < 0) { /* detection */
		if ((config & 0x80) != 0x00
		 || (i2c_smbus_read_byte_data(new_client,
		     ADM1025_REG_STATUS1) & 0xC0) != 0x00
		 || (i2c_smbus_read_byte_data(new_client,
		     ADM1025_REG_STATUS2) & 0xBC) != 0x00) {
			dev_dbg(&adapter->dev,
				"ADM1025 detection failed at 0x%02x.\n",
				address);
			goto exit_free;
		}
	}

	if (kind <= 0) { /* identification */
		u8 man_id, chip_id;

		man_id = i2c_smbus_read_byte_data(new_client,
			 ADM1025_REG_MAN_ID);
		chip_id = i2c_smbus_read_byte_data(new_client,
			  ADM1025_REG_CHIP_ID);
		
		if (man_id == 0x41) { /* Analog Devices */
			if ((chip_id & 0xF0) == 0x20) { /* ADM1025/ADM1025A */
				kind = adm1025;
			}
		} else
		if (man_id == 0xA1) { /* Philips */
			if (address != 0x2E
			 && (chip_id & 0xF0) == 0x20) { /* NE1619 */
				kind = ne1619;
			}
		}

		if (kind <= 0) { /* identification failed */
			dev_info(&adapter->dev,
			    "Unsupported chip (man_id=0x%02X, "
			    "chip_id=0x%02X).\n", man_id, chip_id);
			goto exit_free;
		}
	}

	if (kind == adm1025) {
		name = "adm1025";
	} else if (kind == ne1619) {
		name = "ne1619";
	}

	/* We can fill in the remaining client fields */
	strlcpy(new_client->name, name, I2C_NAME_SIZE);
	new_client->id = adm1025_id++;
	data->valid = 0;
	init_MUTEX(&data->update_lock);

	/* Tell the I2C layer a new client has arrived */
	if ((err = i2c_attach_client(new_client)))
		goto exit_free;

	/* Initialize the ADM1025 chip */
	adm1025_init_client(new_client);

	/* Register sysfs hooks */
	device_create_file(&new_client->dev, &dev_attr_in0_input);
	device_create_file(&new_client->dev, &dev_attr_in1_input);
	device_create_file(&new_client->dev, &dev_attr_in2_input);
	device_create_file(&new_client->dev, &dev_attr_in3_input);
	device_create_file(&new_client->dev, &dev_attr_in5_input);
	device_create_file(&new_client->dev, &dev_attr_in0_min);
	device_create_file(&new_client->dev, &dev_attr_in1_min);
	device_create_file(&new_client->dev, &dev_attr_in2_min);
	device_create_file(&new_client->dev, &dev_attr_in3_min);
	device_create_file(&new_client->dev, &dev_attr_in5_min);
	device_create_file(&new_client->dev, &dev_attr_in0_max);
	device_create_file(&new_client->dev, &dev_attr_in1_max);
	device_create_file(&new_client->dev, &dev_attr_in2_max);
	device_create_file(&new_client->dev, &dev_attr_in3_max);
	device_create_file(&new_client->dev, &dev_attr_in5_max);
	device_create_file(&new_client->dev, &dev_attr_temp1_input);
	device_create_file(&new_client->dev, &dev_attr_temp2_input);
	device_create_file(&new_client->dev, &dev_attr_temp1_min);
	device_create_file(&new_client->dev, &dev_attr_temp2_min);
	device_create_file(&new_client->dev, &dev_attr_temp1_max);
	device_create_file(&new_client->dev, &dev_attr_temp2_max);
	device_create_file(&new_client->dev, &dev_attr_alarms);
	device_create_file(&new_client->dev, &dev_attr_in1_ref);
	device_create_file(&new_client->dev, &dev_attr_vrm);

	/* Pin 11 is either in4 (+12V) or VID4 */
	if (!(config & 0x20)) {
		device_create_file(&new_client->dev, &dev_attr_in4_input);
		device_create_file(&new_client->dev, &dev_attr_in4_min);
		device_create_file(&new_client->dev, &dev_attr_in4_max);
	}

	return 0;

exit_free:
	kfree(data);
exit:
	return err;
}

static void adm1025_init_client(struct i2c_client *client)
{
	u8 reg;
	struct adm1025_data *data = i2c_get_clientdata(client);
	int i;

	data->vrm = 82;

	/*
	 * Set high limits
	 * Usually we avoid setting limits on driver init, but it happens
	 * that the ADM1025 comes with stupid default limits (all registers
	 * set to 0). In case the chip has not gone through any limit
	 * setting yet, we better set the high limits to the max so that
	 * no alarm triggers.
	 */
	for (i=0; i<6; i++) {
		reg = i2c_smbus_read_byte_data(client,
					       ADM1025_REG_IN_MAX(i));
		if (reg == 0)
			i2c_smbus_write_byte_data(client,
						  ADM1025_REG_IN_MAX(i),
						  0xFF);
	}
	for (i=0; i<2; i++) {
		reg = i2c_smbus_read_byte_data(client,
					       ADM1025_REG_TEMP_HIGH(i));
		if (reg == 0)
			i2c_smbus_write_byte_data(client,
						  ADM1025_REG_TEMP_HIGH(i),
						  0x7F);
	}

	/*
	 * Start the conversions
	 */
	reg = i2c_smbus_read_byte_data(client, ADM1025_REG_CONFIG);
	if (!(reg & 0x01))
		i2c_smbus_write_byte_data(client, ADM1025_REG_CONFIG,
					  (reg&0x7E)|0x01);
}

static int adm1025_detach_client(struct i2c_client *client)
{
	int err;

	if ((err = i2c_detach_client(client))) {
		dev_err(&client->dev, "Client deregistration failed, "
			"client not detached.\n");
		return err;
	}

	kfree(i2c_get_clientdata(client));
	return 0;
}

static struct adm1025_data *adm1025_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct adm1025_data *data = i2c_get_clientdata(client);

	down(&data->update_lock);

	if ((jiffies - data->last_updated > HZ * 2) ||
	    (jiffies < data->last_updated) ||
	    !data->valid) {
		int i;

		dev_dbg(&client->dev, "Updating data.\n");
		for (i=0; i<6; i++) {
			data->in[i] = i2c_smbus_read_byte_data(client,
				      ADM1025_REG_IN(i));
			data->in_min[i] = i2c_smbus_read_byte_data(client,
					  ADM1025_REG_IN_MIN(i));
			data->in_max[i] = i2c_smbus_read_byte_data(client,
					  ADM1025_REG_IN_MAX(i));
		}
		for (i=0; i<2; i++) {
			data->temp[i] = i2c_smbus_read_byte_data(client,
					ADM1025_REG_TEMP(i));
			data->temp_min[i] = i2c_smbus_read_byte_data(client,
					    ADM1025_REG_TEMP_LOW(i));
			data->temp_max[i] = i2c_smbus_read_byte_data(client,
					    ADM1025_REG_TEMP_HIGH(i));
		}
		data->alarms = i2c_smbus_read_byte_data(client,
			       ADM1025_REG_STATUS1)
			     | (i2c_smbus_read_byte_data(client,
				ADM1025_REG_STATUS2) << 8);
		data->vid = (i2c_smbus_read_byte_data(client,
			     ADM1025_REG_VID) & 0x0f)
			  | ((i2c_smbus_read_byte_data(client,
			      ADM1025_REG_VID4) & 0x01) << 4);

		data->last_updated = jiffies;
		data->valid = 1;
	}

	up(&data->update_lock);

	return data;
}

static int __init sensors_adm1025_init(void)
{
	return i2c_add_driver(&adm1025_driver);
}

static void __exit sensors_adm1025_exit(void)
{
	i2c_del_driver(&adm1025_driver);
}

MODULE_AUTHOR("Jean Delvare <[e-mail]>");
MODULE_DESCRIPTION("ADM1025 driver");
MODULE_LICENSE("GPL");

module_init(sensors_adm1025_init);
module_exit(sensors_adm1025_exit);