asb100.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

/* VRM */
static ssize_t show_vrm(struct device *dev, char *buf)
{
	struct asb100_data *data = asb100_update_device(dev);
	return sprintf(buf, "%d\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 asb100_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	data->vrm = val;
	return count;
}

/* Alarms */
static DEVICE_ATTR(vrm, S_IRUGO | S_IWUSR, show_vrm, set_vrm);
#define device_create_file_vrm(client) \
device_create_file(&client->dev, &dev_attr_vrm);

static ssize_t show_alarms(struct device *dev, char *buf)
{
	struct asb100_data *data = asb100_update_device(dev);
	return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->alarms));
}

static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
#define device_create_file_alarms(client) \
device_create_file(&client->dev, &dev_attr_alarms)

/* 1 PWM */
static ssize_t show_pwm1(struct device *dev, char *buf)
{
	struct asb100_data *data = asb100_update_device(dev);
	return sprintf(buf, "%d\n", ASB100_PWM_FROM_REG(data->pwm & 0x0f));
}

static ssize_t set_pwm1(struct device *dev, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct asb100_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	data->pwm &= 0x80; /* keep the enable bit */
	data->pwm |= (0x0f & ASB100_PWM_TO_REG(val));
	asb100_write_value(client, ASB100_REG_PWM1, data->pwm);
	return count;
}

static ssize_t show_pwm_enable1(struct device *dev, char *buf)
{
	struct asb100_data *data = asb100_update_device(dev);
	return sprintf(buf, "%d\n", (data->pwm & 0x80) ? 1 : 0);
}

static ssize_t set_pwm_enable1(struct device *dev, const char *buf,
				size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct asb100_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	data->pwm &= 0x0f; /* keep the duty cycle bits */
	data->pwm |= (val ? 0x80 : 0x00);
	asb100_write_value(client, ASB100_REG_PWM1, data->pwm);
	return count;
}

static DEVICE_ATTR(fan1_pwm, S_IRUGO | S_IWUSR, show_pwm1, set_pwm1);
static DEVICE_ATTR(fan1_pwm_enable, S_IRUGO | S_IWUSR,
		show_pwm_enable1, set_pwm_enable1);
#define device_create_file_pwm1(client) do { \
	device_create_file(&new_client->dev, &dev_attr_fan1_pwm); \
	device_create_file(&new_client->dev, &dev_attr_fan1_pwm_enable); \
} while (0)

/* This function is called when:
	asb100_driver is inserted (when this module is loaded), for each
		available adapter
	when a new adapter is inserted (and asb100_driver is still present)
 */
static int asb100_attach_adapter(struct i2c_adapter *adapter)
{
	if (!(adapter->class & I2C_CLASS_HWMON))
		return 0;
	return i2c_detect(adapter, &addr_data, asb100_detect);
}

static int asb100_detect_subclients(struct i2c_adapter *adapter, int address,
		int kind, struct i2c_client *new_client)
{
	int i, id, err;
	struct asb100_data *data = i2c_get_clientdata(new_client);

	data->lm75[0] = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
	if (!(data->lm75[0])) {
		err = -ENOMEM;
		goto ERROR_SC_0;
	}
	memset(data->lm75[0], 0x00, sizeof(struct i2c_client));

	data->lm75[1] = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
	if (!(data->lm75[1])) {
		err = -ENOMEM;
		goto ERROR_SC_1;
	}
	memset(data->lm75[1], 0x00, sizeof(struct i2c_client));

	id = i2c_adapter_id(adapter);

	if (force_subclients[0] == id && force_subclients[1] == address) {
		for (i = 2; i <= 3; i++) {
			if (force_subclients[i] < 0x48 ||
			    force_subclients[i] > 0x4f) {
				dev_err(&new_client->dev, "invalid subclient "
					"address %d; must be 0x48-0x4f\n",
					force_subclients[i]);
				err = -ENODEV;
				goto ERROR_SC_2;
			}
		}
		asb100_write_value(new_client, ASB100_REG_I2C_SUBADDR,
					(force_subclients[2] & 0x07) |
					((force_subclients[3] & 0x07) <<4));
		data->lm75[0]->addr = force_subclients[2];
		data->lm75[1]->addr = force_subclients[3];
	} else {
		int val = asb100_read_value(new_client, ASB100_REG_I2C_SUBADDR);
		data->lm75[0]->addr = 0x48 + (val & 0x07);
		data->lm75[1]->addr = 0x48 + ((val >> 4) & 0x07);
	}

	if(data->lm75[0]->addr == data->lm75[1]->addr) {
		dev_err(&new_client->dev, "duplicate addresses 0x%x "
				"for subclients\n", data->lm75[0]->addr);
		err = -ENODEV;
		goto ERROR_SC_2;
	}

	for (i = 0; i <= 1; i++) {
		i2c_set_clientdata(data->lm75[i], NULL);
		data->lm75[i]->adapter = adapter;
		data->lm75[i]->driver = &asb100_driver;
		data->lm75[i]->flags = 0;
		strlcpy(data->lm75[i]->name, "asb100 subclient", I2C_NAME_SIZE);
	}

	if ((err = i2c_attach_client(data->lm75[0]))) {
		dev_err(&new_client->dev, "subclient %d registration "
			"at address 0x%x failed.\n", i, data->lm75[0]->addr);
		goto ERROR_SC_2;
	}

	if ((err = i2c_attach_client(data->lm75[1]))) {
		dev_err(&new_client->dev, "subclient %d registration "
			"at address 0x%x failed.\n", i, data->lm75[1]->addr);
		goto ERROR_SC_3;
	}

	return 0;

/* Undo inits in case of errors */
ERROR_SC_3:
	i2c_detach_client(data->lm75[0]);
ERROR_SC_2:
	kfree(data->lm75[1]);
ERROR_SC_1:
	kfree(data->lm75[0]);
ERROR_SC_0:
	return err;
}

static int asb100_detect(struct i2c_adapter *adapter, int address, int kind)
{
	int err;
	struct i2c_client *new_client;
	struct asb100_data *data;

	/* asb100 is SMBus only */
	if (i2c_is_isa_adapter(adapter)) {
		pr_debug("asb100.o: detect failed, "
				"cannot attach to legacy adapter!\n");
		err = -ENODEV;
		goto ERROR0;
	}

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
		pr_debug("asb100.o: detect failed, "
				"smbus byte data not supported!\n");
		err = -ENODEV;
		goto ERROR0;
	}

	/* OK. For now, we presume we have a valid client. We now create the
	   client structure, even though we cannot fill it completely yet.
	   But it allows us to access asb100_{read,write}_value. */

	if (!(data = kmalloc(sizeof(struct asb100_data), GFP_KERNEL))) {
		pr_debug("asb100.o: detect failed, kmalloc failed!\n");
		err = -ENOMEM;
		goto ERROR0;
	}
	memset(data, 0, sizeof(struct asb100_data));

	new_client = &data->client;
	init_MUTEX(&data->lock);
	i2c_set_clientdata(new_client, data);
	new_client->addr = address;
	new_client->adapter = adapter;
	new_client->driver = &asb100_driver;
	new_client->flags = 0;

	/* Now, we do the remaining detection. */

	/* The chip may be stuck in some other bank than bank 0. This may
	   make reading other information impossible. Specify a force=... or
	   force_*=... parameter, and the chip will be reset to the right
	   bank. */
	if (kind < 0) {

		int val1 = asb100_read_value(new_client, ASB100_REG_BANK);
		int val2 = asb100_read_value(new_client, ASB100_REG_CHIPMAN);

		/* If we're in bank 0 */
		if ( (!(val1 & 0x07)) &&
				/* Check for ASB100 ID (low byte) */
				( ((!(val1 & 0x80)) && (val2 != 0x94)) ||
				/* Check for ASB100 ID (high byte ) */
				((val1 & 0x80) && (val2 != 0x06)) ) ) {
			pr_debug("asb100.o: detect failed, "
					"bad chip id 0x%02x!\n", val2);
			err = -ENODEV;
			goto ERROR1;
		}

	} /* kind < 0 */

	/* We have either had a force parameter, or we have already detected
	   Winbond. Put it now into bank 0 and Vendor ID High Byte */
	asb100_write_value(new_client, ASB100_REG_BANK,
		(asb100_read_value(new_client, ASB100_REG_BANK) & 0x78) | 0x80);

	/* Determine the chip type. */
	if (kind <= 0) {
		int val1 = asb100_read_value(new_client, ASB100_REG_WCHIPID);
		int val2 = asb100_read_value(new_client, ASB100_REG_CHIPMAN);

		if ((val1 == 0x31) && (val2 == 0x06))
			kind = asb100;
		else {
			if (kind == 0)
				dev_warn(&new_client->dev, "ignoring "
					"'force' parameter for unknown chip "
					"at adapter %d, address 0x%02x.\n",
					i2c_adapter_id(adapter), address);
			err = -ENODEV;
			goto ERROR1;
		}
	}

	/* Fill in remaining client fields and put it into the global list */
	strlcpy(new_client->name, "asb100", I2C_NAME_SIZE);
	data->type = kind;

	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 ERROR1;

	/* Attach secondary lm75 clients */
	if ((err = asb100_detect_subclients(adapter, address, kind,
			new_client)))
		goto ERROR2;

	/* Initialize the chip */
	asb100_init_client(new_client);

	/* A few vars need to be filled upon startup */
	data->fan_min[0] = asb100_read_value(new_client, ASB100_REG_FAN_MIN(0));
	data->fan_min[1] = asb100_read_value(new_client, ASB100_REG_FAN_MIN(1));
	data->fan_min[2] = asb100_read_value(new_client, ASB100_REG_FAN_MIN(2));

	/* Register sysfs hooks */
	device_create_file_in(new_client, 0);
	device_create_file_in(new_client, 1);
	device_create_file_in(new_client, 2);
	device_create_file_in(new_client, 3);
	device_create_file_in(new_client, 4);
	device_create_file_in(new_client, 5);
	device_create_file_in(new_client, 6);

	device_create_file_fan(new_client, 1);
	device_create_file_fan(new_client, 2);
	device_create_file_fan(new_client, 3);

	device_create_file_temp(new_client, 1);
	device_create_file_temp(new_client, 2);
	device_create_file_temp(new_client, 3);
	device_create_file_temp(new_client, 4);

	device_create_file_vid(new_client);
	device_create_file_vrm(new_client);

	device_create_file_alarms(new_client);

	device_create_file_pwm1(new_client);

	return 0;

ERROR2:
	i2c_detach_client(new_client);
ERROR1:
	kfree(data);
ERROR0:
	return err;
}

static int asb100_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;
	}

	if (i2c_get_clientdata(client)==NULL) {
		/* subclients */
		kfree(client);
	} else {
		/* main client */
		kfree(i2c_get_clientdata(client));
	}

	return 0;
}

/* The SMBus locks itself, usually, but nothing may access the chip between
   bank switches. */
static int asb100_read_value(struct i2c_client *client, u16 reg)
{
	struct asb100_data *data = i2c_get_clientdata(client);
	struct i2c_client *cl;
	int res, bank;

	down(&data->lock);

	bank = (reg >> 8) & 0x0f;
	if (bank > 2)
		/* switch banks */
		i2c_smbus_write_byte_data(client, ASB100_REG_BANK, bank);

	if (bank == 0 || bank > 2) {
		res = i2c_smbus_read_byte_data(client, reg & 0xff);
	} else {
		/* switch to subclient */
		cl = data->lm75[bank - 1];

		/* convert from ISA to LM75 I2C addresses */
		switch (reg & 0xff) {
		case 0x50: /* TEMP */
			res = swab16(i2c_smbus_read_word_data (cl, 0));
			break;
		case 0x52: /* CONFIG */
			res = i2c_smbus_read_byte_data(cl, 1);
			break;
		case 0x53: /* HYST */
			res = swab16(i2c_smbus_read_word_data (cl, 2));
			break;
		case 0x55: /* MAX */
		default:
			res = swab16(i2c_smbus_read_word_data (cl, 3));
			break;
		}
	}

	if (bank > 2)
		i2c_smbus_write_byte_data(client, ASB100_REG_BANK, 0);

	up(&data->lock);

	return res;
}

static void asb100_write_value(struct i2c_client *client, u16 reg, u16 value)
{
	struct asb100_data *data = i2c_get_clientdata(client);
	struct i2c_client *cl;
	int bank;

	down(&data->lock);

	bank = (reg >> 8) & 0x0f;
	if (bank > 2)
		/* switch banks */
		i2c_smbus_write_byte_data(client, ASB100_REG_BANK, bank);

	if (bank == 0 || bank > 2) {
		i2c_smbus_write_byte_data(client, reg & 0xff, value & 0xff);
	} else {
		/* switch to subclient */
		cl = data->lm75[bank - 1];

		/* convert from ISA to LM75 I2C addresses */
		switch (reg & 0xff) {
		case 0x52: /* CONFIG */
			i2c_smbus_write_byte_data(cl, 1, value & 0xff);
			break;
		case 0x53: /* HYST */
			i2c_smbus_write_word_data(cl, 2, swab16(value));
			break;
		case 0x55: /* MAX */
			i2c_smbus_write_word_data(cl, 3, swab16(value));
			break;
		}
	}

	if (bank > 2)
		i2c_smbus_write_byte_data(client, ASB100_REG_BANK, 0);

	up(&data->lock);
}

static void asb100_init_client(struct i2c_client *client)
{
	struct asb100_data *data = i2c_get_clientdata(client);
	int vid = 0;

	vid = asb100_read_value(client, ASB100_REG_VID_FANDIV) & 0x0f;
	vid |= (asb100_read_value(client, ASB100_REG_CHIPID) & 0x01) << 4;
	data->vrm = ASB100_DEFAULT_VRM;
	vid = vid_from_reg(vid, data->vrm);

	/* Start monitoring */
	asb100_write_value(client, ASB100_REG_CONFIG, 
		(asb100_read_value(client, ASB100_REG_CONFIG) & 0xf7) | 0x01);
}

static struct asb100_data *asb100_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct asb100_data *data = i2c_get_clientdata(client);
	int i;

	down(&data->update_lock);

	if (time_after(jiffies - data->last_updated, (unsigned long)(HZ+HZ/2))
		|| time_before(jiffies, data->last_updated) || !data->valid) {

		dev_dbg(&client->dev, "starting device update...\n");

		/* 7 voltage inputs */
		for (i = 0; i < 7; i++) {
			data->in[i] = asb100_read_value(client,
				ASB100_REG_IN(i));
			data->in_min[i] = asb100_read_value(client,
				ASB100_REG_IN_MIN(i));
			data->in_max[i] = asb100_read_value(client,
				ASB100_REG_IN_MAX(i));
		}

		/* 3 fan inputs */
		for (i = 0; i < 3; i++) {
			data->fan[i] = asb100_read_value(client,
					ASB100_REG_FAN(i));
			data->fan_min[i] = asb100_read_value(client,
					ASB100_REG_FAN_MIN(i));
		}

		/* 4 temperature inputs */
		for (i = 1; i <= 4; i++) {
			data->temp[i-1] = asb100_read_value(client,
					ASB100_REG_TEMP(i));
			data->temp_max[i-1] = asb100_read_value(client,
					ASB100_REG_TEMP_MAX(i));
			data->temp_hyst[i-1] = asb100_read_value(client,
					ASB100_REG_TEMP_HYST(i));
		}

		/* VID and fan divisors */
		i = asb100_read_value(client, ASB100_REG_VID_FANDIV);
		data->vid = i & 0x0f;
		data->vid |= (asb100_read_value(client,
				ASB100_REG_CHIPID) & 0x01) << 4;
		data->fan_div[0] = (i >> 4) & 0x03;
		data->fan_div[1] = (i >> 6) & 0x03;
		data->fan_div[2] = (asb100_read_value(client,
				ASB100_REG_PIN) >> 6) & 0x03;

		/* PWM */
		data->pwm = asb100_read_value(client, ASB100_REG_PWM1);

		/* alarms */
		data->alarms = asb100_read_value(client, ASB100_REG_ALARM1) +
			(asb100_read_value(client, ASB100_REG_ALARM2) << 8);

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

		dev_dbg(&client->dev, "... device update complete\n");
	}

	up(&data->update_lock);

	return data;
}

static int __init asb100_init(void)
{
	return i2c_add_driver(&asb100_driver);
}

static void __exit asb100_exit(void)
{
	i2c_del_driver(&asb100_driver);
}

MODULE_AUTHOR("Mark M. Hoffman <[e-mail]>");
MODULE_DESCRIPTION("ASB100 Bach driver");
MODULE_LICENSE("GPL");

module_init(asb100_init);
module_exit(asb100_exit);