via686a.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

	u16 twoBits = val & 3;

	/* no interpolation for these */
	if (twoBits == 0 || eightBits == 255)
		return TEMP_FROM_REG(eightBits);

	/* do some linear interpolation */
	return (tempLUT[eightBits] * (4 - twoBits) +
	        tempLUT[eightBits + 1] * twoBits) * 25;
}

#define ALARMS_FROM_REG(val) (val)

#define DIV_FROM_REG(val) (1 << (val))
#define DIV_TO_REG(val) ((val)==8?3:(val)==4?2:(val)==1?0:1)

/* For the VIA686A, we need to keep some data in memory.
   The structure is dynamically allocated, at the same time when a new
   via686a client is allocated. */
struct via686a_data {
	struct i2c_client client;
	struct semaphore update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	u8 in[5];		/* Register value */
	u8 in_max[5];		/* Register value */
	u8 in_min[5];		/* Register value */
	u8 fan[2];		/* Register value */
	u8 fan_min[2];		/* Register value */
	u16 temp[3];		/* Register value 10 bit */
	u8 temp_over[3];	/* Register value */
	u8 temp_hyst[3];	/* Register value */
	u8 fan_div[2];		/* Register encoding, shifted right */
	u16 alarms;		/* Register encoding, combined */
};

static struct pci_dev *s_bridge;	/* pointer to the (only) via686a */

static int via686a_attach_adapter(struct i2c_adapter *adapter);
static int via686a_detect(struct i2c_adapter *adapter, int address, int kind);
static int via686a_detach_client(struct i2c_client *client);

static inline int via686a_read_value(struct i2c_client *client, u8 reg)
{
	return (inb_p(client->addr + reg));
}

static inline void via686a_write_value(struct i2c_client *client, u8 reg,
				       u8 value)
{
	outb_p(value, client->addr + reg);
}

static struct via686a_data *via686a_update_device(struct device *dev);
static void via686a_init_client(struct i2c_client *client);

/* following are the sysfs callback functions */

/* 7 voltage sensors */
static ssize_t show_in(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in[nr], nr));
}

static ssize_t show_in_min(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_min[nr], nr));
}

static ssize_t show_in_max(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_max[nr], nr));
}

static ssize_t set_in_min(struct device *dev, const char *buf, 
		size_t count, int nr) {
	struct i2c_client *client = to_i2c_client(dev);
	struct via686a_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	data->in_min[nr] = IN_TO_REG(val,nr);
	via686a_write_value(client, VIA686A_REG_IN_MIN(nr), 
			data->in_min[nr]);
	return count;
}
static ssize_t set_in_max(struct device *dev, const char *buf, 
		size_t count, int nr) {
	struct i2c_client *client = to_i2c_client(dev);
	struct via686a_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);
	data->in_max[nr] = IN_TO_REG(val,nr);
	via686a_write_value(client, VIA686A_REG_IN_MAX(nr), 
			data->in_max[nr]);
	return count;
}
#define show_in_offset(offset)					\
static ssize_t 							\
	show_in##offset (struct device *dev, char *buf)		\
{								\
	return show_in(dev, buf, 0x##offset);			\
}								\
static ssize_t 							\
	show_in##offset##_min (struct device *dev, char *buf)	\
{								\
	return show_in_min(dev, buf, 0x##offset);		\
}								\
static ssize_t 							\
	show_in##offset##_max (struct device *dev, char *buf)	\
{								\
	return show_in_max(dev, buf, 0x##offset);		\
}								\
static ssize_t set_in##offset##_min (struct device *dev, 	\
		const char *buf, size_t count) 			\
{								\
	return set_in_min(dev, buf, count, 0x##offset);		\
}								\
static ssize_t set_in##offset##_max (struct device *dev,	\
			const char *buf, size_t count)		\
{								\
	return set_in_max(dev, buf, count, 0x##offset);		\
}								\
static DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in##offset, NULL);\
static DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR, 	\
		show_in##offset##_min, set_in##offset##_min);	\
static DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR, 	\
		show_in##offset##_max, set_in##offset##_max);

show_in_offset(0);
show_in_offset(1);
show_in_offset(2);
show_in_offset(3);
show_in_offset(4);

/* 3 temperatures */
static ssize_t show_temp(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf, "%ld\n", TEMP_FROM_REG10(data->temp[nr]));
}
static ssize_t show_temp_over(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_over[nr]));
}
static ssize_t show_temp_hyst(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_hyst[nr]));
}
static ssize_t set_temp_over(struct device *dev, const char *buf, 
		size_t count, int nr) {
	struct i2c_client *client = to_i2c_client(dev);
	struct via686a_data *data = i2c_get_clientdata(client);
	int val = simple_strtol(buf, NULL, 10);
	data->temp_over[nr] = TEMP_TO_REG(val);
	via686a_write_value(client, VIA686A_REG_TEMP_OVER(nr), data->temp_over[nr]);
	return count;
}
static ssize_t set_temp_hyst(struct device *dev, const char *buf, 
		size_t count, int nr) {
	struct i2c_client *client = to_i2c_client(dev);
	struct via686a_data *data = i2c_get_clientdata(client);
	int val = simple_strtol(buf, NULL, 10);
	data->temp_hyst[nr] = TEMP_TO_REG(val);
	via686a_write_value(client, VIA686A_REG_TEMP_HYST(nr), data->temp_hyst[nr]);
	return count;
}
#define show_temp_offset(offset)					\
static ssize_t show_temp_##offset (struct device *dev, char *buf)	\
{									\
	return show_temp(dev, buf, 0x##offset - 1);			\
}									\
static ssize_t								\
show_temp_##offset##_over (struct device *dev, char *buf)		\
{									\
	return show_temp_over(dev, buf, 0x##offset - 1);			\
}									\
static ssize_t								\
show_temp_##offset##_hyst (struct device *dev, char *buf)		\
{									\
	return show_temp_hyst(dev, buf, 0x##offset - 1);			\
}									\
static ssize_t set_temp_##offset##_over (struct device *dev, 		\
		const char *buf, size_t count) 				\
{									\
	return set_temp_over(dev, buf, count, 0x##offset - 1);		\
}									\
static ssize_t set_temp_##offset##_hyst (struct device *dev, 		\
		const char *buf, size_t count) 				\
{									\
	return set_temp_hyst(dev, buf, count, 0x##offset - 1);		\
}									\
static DEVICE_ATTR(temp##offset##_input, S_IRUGO, show_temp_##offset, NULL);\
static DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR, 		\
		show_temp_##offset##_over, set_temp_##offset##_over);	\
static DEVICE_ATTR(temp##offset##_max_hyst, S_IRUGO | S_IWUSR, 		\
		show_temp_##offset##_hyst, set_temp_##offset##_hyst);	

show_temp_offset(1);
show_temp_offset(2);
show_temp_offset(3);

/* 2 Fans */
static ssize_t show_fan(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf,"%d\n", FAN_FROM_REG(data->fan[nr], 
				DIV_FROM_REG(data->fan_div[nr])) );
}
static ssize_t show_fan_min(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf,"%d\n",
		FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr])) );
}
static ssize_t show_fan_div(struct device *dev, char *buf, int nr) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf,"%d\n", DIV_FROM_REG(data->fan_div[nr]) );
}
static ssize_t set_fan_min(struct device *dev, const char *buf, 
		size_t count, int nr) {
	struct i2c_client *client = to_i2c_client(dev);
	struct via686a_data *data = i2c_get_clientdata(client);
	int val = simple_strtol(buf, NULL, 10);
	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
	via686a_write_value(client, VIA686A_REG_FAN_MIN(nr+1), data->fan_min[nr]);
	return count;
}
static ssize_t set_fan_div(struct device *dev, const char *buf, 
		size_t count, int nr) {
	struct i2c_client *client = to_i2c_client(dev);
	struct via686a_data *data = i2c_get_clientdata(client);
	int val = simple_strtol(buf, NULL, 10);
	int old = via686a_read_value(client, VIA686A_REG_FANDIV);
	data->fan_div[nr] = DIV_TO_REG(val);
	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
	via686a_write_value(client, VIA686A_REG_FANDIV, old);
	return count;
}

#define show_fan_offset(offset)						\
static ssize_t show_fan_##offset (struct device *dev, char *buf)	\
{									\
	return show_fan(dev, buf, 0x##offset - 1);			\
}									\
static ssize_t show_fan_##offset##_min (struct device *dev, char *buf)	\
{									\
	return show_fan_min(dev, buf, 0x##offset - 1);			\
}									\
static ssize_t show_fan_##offset##_div (struct device *dev, char *buf)	\
{									\
	return show_fan_div(dev, buf, 0x##offset - 1);			\
}									\
static ssize_t set_fan_##offset##_min (struct device *dev, 		\
	const char *buf, size_t count) 					\
{									\
	return set_fan_min(dev, buf, count, 0x##offset - 1);		\
}									\
static ssize_t set_fan_##offset##_div (struct device *dev, 		\
		const char *buf, size_t count) 				\
{									\
	return set_fan_div(dev, buf, count, 0x##offset - 1);		\
}									\
static DEVICE_ATTR(fan##offset##_input, S_IRUGO, show_fan_##offset, NULL);\
static DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR, 		\
		show_fan_##offset##_min, set_fan_##offset##_min);	\
static DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, 		\
		show_fan_##offset##_div, set_fan_##offset##_div);

show_fan_offset(1);
show_fan_offset(2);

/* Alarms */
static ssize_t show_alarms(struct device *dev, char *buf) {
	struct via686a_data *data = via686a_update_device(dev);
	return sprintf(buf,"%d\n", ALARMS_FROM_REG(data->alarms));
}
static DEVICE_ATTR(alarms, S_IRUGO | S_IWUSR, show_alarms, NULL);

/* The driver. I choose to use type i2c_driver, as at is identical to both
   smbus_driver and isa_driver, and clients could be of either kind */
static struct i2c_driver via686a_driver = {
	.owner		= THIS_MODULE,
	.name		= "via686a",
	.id		= I2C_DRIVERID_VIA686A,
	.flags		= I2C_DF_NOTIFY,
	.attach_adapter	= via686a_attach_adapter,
	.detach_client	= via686a_detach_client,
};