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hwmon: (it87) Fix multi-line comments
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Fix multi-line comments, and clean up some of the affected comments.

Cc: Jean Delvare <khali@linux-fr.org>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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Guenter Roeck authored and Guenter Roeck committed Mar 19, 2012
1 parent 86d566e commit 4a0d71c
Showing 1 changed file with 108 additions and 62 deletions.
170 changes: 108 additions & 62 deletions drivers/hwmon/it87.c
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Original file line number Diff line number Diff line change
Expand Up @@ -176,12 +176,16 @@ static bool fix_pwm_polarity;
#define IT87_REG_ALARM2 0x02
#define IT87_REG_ALARM3 0x03

/* The IT8718F and IT8720F have the VID value in a different register, in
Super-I/O configuration space. */
/*
* The IT8718F and IT8720F have the VID value in a different register, in
* Super-I/O configuration space.
*/
#define IT87_REG_VID 0x0a
/* The IT8705F and IT8712F earlier than revision 0x08 use register 0x0b
for fan divisors. Later IT8712F revisions must use 16-bit tachometer
mode. */
/*
* The IT8705F and IT8712F earlier than revision 0x08 use register 0x0b
* for fan divisors. Later IT8712F revisions must use 16-bit tachometer
* mode.
*/
#define IT87_REG_FAN_DIV 0x0b
#define IT87_REG_FAN_16BIT 0x0c

Expand Down Expand Up @@ -227,8 +231,10 @@ struct it87_sio_data {
u8 skip_pwm;
};

/* For each registered chip, we need to keep some data in memory.
The structure is dynamically allocated. */
/*
* For each registered chip, we need to keep some data in memory.
* The structure is dynamically allocated.
*/
struct it87_data {
struct device *hwmon_dev;
enum chips type;
Expand Down Expand Up @@ -259,14 +265,16 @@ struct it87_data {
u8 fan_main_ctrl; /* Register value */
u8 fan_ctl; /* Register value */

/* The following 3 arrays correspond to the same registers up to
/*
* The following 3 arrays correspond to the same registers up to
* the IT8720F. The meaning of bits 6-0 depends on the value of bit
* 7, and we want to preserve settings on mode changes, so we have
* to track all values separately.
* Starting with the IT8721F, the manual PWM duty cycles are stored
* in separate registers (8-bit values), so the separate tracking
* is no longer needed, but it is still done to keep the driver
* simple. */
* simple.
*/
u8 pwm_ctrl[3]; /* Register value */
u8 pwm_duty[3]; /* Manual PWM value set by user */
u8 pwm_temp_map[3]; /* PWM to temp. chan. mapping (bits 1-0) */
Expand Down Expand Up @@ -388,9 +396,11 @@ static const unsigned int pwm_freq[8] = {

static inline int has_16bit_fans(const struct it87_data *data)
{
/* IT8705F Datasheet 0.4.1, 3h == Version G.
IT8712F Datasheet 0.9.1, section 8.3.5 indicates 8h == Version J.
These are the first revisions with 16bit tachometer support. */
/*
* IT8705F Datasheet 0.4.1, 3h == Version G.
* IT8712F Datasheet 0.9.1, section 8.3.5 indicates 8h == Version J.
* These are the first revisions with 16-bit tachometer support.
*/
return (data->type == it87 && data->revision >= 0x03)
|| (data->type == it8712 && data->revision >= 0x08)
|| data->type == it8716
Expand All @@ -402,9 +412,11 @@ static inline int has_16bit_fans(const struct it87_data *data)

static inline int has_old_autopwm(const struct it87_data *data)
{
/* The old automatic fan speed control interface is implemented
by IT8705F chips up to revision F and IT8712F chips up to
revision G. */
/*
* The old automatic fan speed control interface is implemented
* by IT8705F chips up to revision F and IT8712F chips up to
* revision G.
*/
return (data->type == it87 && data->revision < 0x03)
|| (data->type == it8712 && data->revision < 0x08);
}
Expand Down Expand Up @@ -606,10 +618,8 @@ static ssize_t show_sensor(struct device *dev, struct device_attribute *attr,
{
struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
int nr = sensor_attr->index;

struct it87_data *data = it87_update_device(dev);
u8 reg = data->sensor; /* In case the value is updated while
we use it */
u8 reg = data->sensor; /* In case value is updated while used */

if (reg & (1 << nr))
return sprintf(buf, "3\n"); /* thermal diode */
Expand Down Expand Up @@ -894,8 +904,10 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,

mutex_lock(&data->update_lock);
if (has_newer_autopwm(data)) {
/* If we are in automatic mode, the PWM duty cycle register
* is read-only so we can't write the value */
/*
* If we are in automatic mode, the PWM duty cycle register
* is read-only so we can't write the value.
*/
if (data->pwm_ctrl[nr] & 0x80) {
mutex_unlock(&data->update_lock);
return -EBUSY;
Expand All @@ -905,8 +917,10 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
data->pwm_duty[nr]);
} else {
data->pwm_duty[nr] = pwm_to_reg(data, val);
/* If we are in manual mode, write the duty cycle immediately;
* otherwise, just store it for later use. */
/*
* If we are in manual mode, write the duty cycle immediately;
* otherwise, just store it for later use.
*/
if (!(data->pwm_ctrl[nr] & 0x80)) {
data->pwm_ctrl[nr] = data->pwm_duty[nr];
it87_write_value(data, IT87_REG_PWM(nr),
Expand Down Expand Up @@ -965,8 +979,10 @@ static ssize_t set_pwm_temp_map(struct device *dev,
long val;
u8 reg;

/* This check can go away if we ever support automatic fan speed
control on newer chips. */
/*
* This check can go away if we ever support automatic fan speed
* control on newer chips.
*/
if (!has_old_autopwm(data)) {
dev_notice(dev, "Mapping change disabled for safety reasons\n");
return -EINVAL;
Expand All @@ -991,8 +1007,10 @@ static ssize_t set_pwm_temp_map(struct device *dev,

mutex_lock(&data->update_lock);
data->pwm_temp_map[nr] = reg;
/* If we are in automatic mode, write the temp mapping immediately;
* otherwise, just store it for later use. */
/*
* If we are in automatic mode, write the temp mapping immediately;
* otherwise, just store it for later use.
*/
if (data->pwm_ctrl[nr] & 0x80) {
data->pwm_ctrl[nr] = 0x80 | data->pwm_temp_map[nr];
it87_write_value(data, IT87_REG_PWM(nr), data->pwm_ctrl[nr]);
Expand Down Expand Up @@ -1162,9 +1180,11 @@ static ssize_t set_fan16_min(struct device *dev, struct device_attribute *attr,
return count;
}

/* We want to use the same sysfs file names as 8-bit fans, but we need
different variable names, so we have to use SENSOR_ATTR instead of
SENSOR_DEVICE_ATTR. */
/*
* We want to use the same sysfs file names as 8-bit fans, but we need
* different variable names, so we have to use SENSOR_ATTR instead of
* SENSOR_DEVICE_ATTR.
*/
#define show_fan16_offset(offset) \
static struct sensor_device_attribute sensor_dev_attr_fan##offset##_input16 \
= SENSOR_ATTR(fan##offset##_input, S_IRUGO, \
Expand Down Expand Up @@ -1736,12 +1756,14 @@ static int __init it87_find(unsigned short *address,
if (board_vendor && board_name) {
if (strcmp(board_vendor, "nVIDIA") == 0
&& strcmp(board_name, "FN68PT") == 0) {
/* On the Shuttle SN68PT, FAN_CTL2 is apparently not
connected to a fan, but to something else. One user
has reported instant system power-off when changing
the PWM2 duty cycle, so we disable it.
I use the board name string as the trigger in case
the same board is ever used in other systems. */
/*
* On the Shuttle SN68PT, FAN_CTL2 is apparently not
* connected to a fan, but to something else. One user
* has reported instant system power-off when changing
* the PWM2 duty cycle, so we disable it.
* I use the board name string as the trigger in case
* the same board is ever used in other systems.
*/
pr_info("Disabling pwm2 due to hardware constraints\n");
sio_data->skip_pwm = (1 << 1);
}
Expand Down Expand Up @@ -1879,9 +1901,11 @@ static int __devinit it87_probe(struct platform_device *pdev)
if (!fan_beep_need_rw)
continue;

/* As we have a single beep enable bit for all fans,
/*
* As we have a single beep enable bit for all fans,
* only the first enabled fan has a writable attribute
* for it. */
* for it.
*/
if (sysfs_chmod_file(&dev->kobj,
it87_attributes_fan_beep[i],
S_IRUGO | S_IWUSR))
Expand Down Expand Up @@ -1961,18 +1985,22 @@ static int __devexit it87_remove(struct platform_device *pdev)
return 0;
}

/* Must be called with data->update_lock held, except during initialization.
We ignore the IT87 BUSY flag at this moment - it could lead to deadlocks,
would slow down the IT87 access and should not be necessary. */
/*
* Must be called with data->update_lock held, except during initialization.
* We ignore the IT87 BUSY flag at this moment - it could lead to deadlocks,
* would slow down the IT87 access and should not be necessary.
*/
static int it87_read_value(struct it87_data *data, u8 reg)
{
outb_p(reg, data->addr + IT87_ADDR_REG_OFFSET);
return inb_p(data->addr + IT87_DATA_REG_OFFSET);
}

/* Must be called with data->update_lock held, except during initialization.
We ignore the IT87 BUSY flag at this moment - it could lead to deadlocks,
would slow down the IT87 access and should not be necessary. */
/*
* Must be called with data->update_lock held, except during initialization.
* We ignore the IT87 BUSY flag at this moment - it could lead to deadlocks,
* would slow down the IT87 access and should not be necessary.
*/
static void it87_write_value(struct it87_data *data, u8 reg, u8 value)
{
outb_p(reg, data->addr + IT87_ADDR_REG_OFFSET);
Expand All @@ -1983,26 +2011,32 @@ static void it87_write_value(struct it87_data *data, u8 reg, u8 value)
static int __devinit it87_check_pwm(struct device *dev)
{
struct it87_data *data = dev_get_drvdata(dev);
/* Some BIOSes fail to correctly configure the IT87 fans. All fans off
/*
* Some BIOSes fail to correctly configure the IT87 fans. All fans off
* and polarity set to active low is sign that this is the case so we
* disable pwm control to protect the user. */
* disable pwm control to protect the user.
*/
int tmp = it87_read_value(data, IT87_REG_FAN_CTL);
if ((tmp & 0x87) == 0) {
if (fix_pwm_polarity) {
/* The user asks us to attempt a chip reconfiguration.
/*
* The user asks us to attempt a chip reconfiguration.
* This means switching to active high polarity and
* inverting all fan speed values. */
* inverting all fan speed values.
*/
int i;
u8 pwm[3];

for (i = 0; i < 3; i++)
pwm[i] = it87_read_value(data,
IT87_REG_PWM(i));

/* If any fan is in automatic pwm mode, the polarity
/*
* If any fan is in automatic pwm mode, the polarity
* might be correct, as suspicious as it seems, so we
* better don't change anything (but still disable the
* PWM interface). */
* PWM interface).
*/
if (!((pwm[0] | pwm[1] | pwm[2]) & 0x80)) {
dev_info(dev, "Reconfiguring PWM to "
"active high polarity\n");
Expand Down Expand Up @@ -2038,7 +2072,8 @@ static void __devinit it87_init_device(struct platform_device *pdev)
int tmp, i;
u8 mask;

/* For each PWM channel:
/*
* For each PWM channel:
* - If it is in automatic mode, setting to manual mode should set
* the fan to full speed by default.
* - If it is in manual mode, we need a mapping to temperature
Expand All @@ -2048,18 +2083,21 @@ static void __devinit it87_init_device(struct platform_device *pdev)
* prior to switching to a different mode.
* Note that this is no longer needed for the IT8721F and later, as
* these have separate registers for the temperature mapping and the
* manual duty cycle. */
* manual duty cycle.
*/
for (i = 0; i < 3; i++) {
data->pwm_temp_map[i] = i;
data->pwm_duty[i] = 0x7f; /* Full speed */
data->auto_pwm[i][3] = 0x7f; /* Full speed, hard-coded */
}

/* Some chips seem to have default value 0xff for all limit
/*
* Some chips seem to have default value 0xff for all limit
* registers. For low voltage limits it makes no sense and triggers
* alarms, so change to 0 instead. For high temperature limits, it
* means -1 degree C, which surprisingly doesn't trigger an alarm,
* but is still confusing, so change to 127 degrees C. */
* but is still confusing, so change to 127 degrees C.
*/
for (i = 0; i < 8; i++) {
tmp = it87_read_value(data, IT87_REG_VIN_MIN(i));
if (tmp == 0xff)
Expand All @@ -2071,10 +2109,12 @@ static void __devinit it87_init_device(struct platform_device *pdev)
it87_write_value(data, IT87_REG_TEMP_HIGH(i), 127);
}

/* Temperature channels are not forcibly enabled, as they can be
/*
* Temperature channels are not forcibly enabled, as they can be
* set to two different sensor types and we can't guess which one
* is correct for a given system. These channels can be enabled at
* run-time through the temp{1-3}_type sysfs accessors if needed. */
* run-time through the temp{1-3}_type sysfs accessors if needed.
*/

/* Check if voltage monitors are reset manually or by some reason */
tmp = it87_read_value(data, IT87_REG_VIN_ENABLE);
Expand Down Expand Up @@ -2157,8 +2197,10 @@ static struct it87_data *it87_update_device(struct device *dev)
if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
|| !data->valid) {
if (update_vbat) {
/* Cleared after each update, so reenable. Value
returned by this read will be previous value */
/*
* Cleared after each update, so reenable. Value
* returned by this read will be previous value
*/
it87_write_value(data, IT87_REG_CONFIG,
it87_read_value(data, IT87_REG_CONFIG) | 0x40);
}
Expand Down Expand Up @@ -2220,13 +2262,17 @@ static struct it87_data *it87_update_device(struct device *dev)
it87_update_pwm_ctrl(data, i);

data->sensor = it87_read_value(data, IT87_REG_TEMP_ENABLE);
/* The 8705 does not have VID capability.
The 8718 and later don't use IT87_REG_VID for the
same purpose. */
/*
* The IT8705F does not have VID capability.
* The IT8718F and later don't use IT87_REG_VID for the
* same purpose.
*/
if (data->type == it8712 || data->type == it8716) {
data->vid = it87_read_value(data, IT87_REG_VID);
/* The older IT8712F revisions had only 5 VID pins,
but we assume it is always safe to read 6 bits. */
/*
* The older IT8712F revisions had only 5 VID pins,
* but we assume it is always safe to read 6 bits.
*/
data->vid &= 0x3f;
}
data->last_updated = jiffies;
Expand Down

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