[RFC PATCH v2 1/3] hwmon: pmbus: Add fan control support
Andrew Jeffery
andrew at aj.id.au
Tue Jul 18 13:36:51 AEST 2017
Expose fanX_target, pwmX and pwmX_enable hwmon sysfs attributes.
Fans in a PMBus device are driven by the configuration of two registers:
FAN_CONFIG_x_y and FAN_COMMAND_x: FAN_CONFIG_x_y dictates how the fan
and the tacho operate (if installed), while FAN_COMMAND_x sets the
desired fan rate. The unit of FAN_COMMAND_x is dependent on the
operational fan mode, RPM or PWM percent duty, as determined by the
corresponding FAN_CONFIG_x_y.
The mapping of fanX_target, pwmX and pwmX_enable onto FAN_CONFIG_x_y and
FAN_COMMAND_x is implemented with the addition of virtual registers and
generic implementations in the core:
1. PMBUS_VIRT_FAN_TARGET_x
2. PMBUS_VIRT_PWM_x
3. PMBUS_VIRT_PWM_ENABLE_x
The facilitate the necessary side-effects of each access. Examples of
the read case, assuming m = 1, b = 0, R = 0:
Read | With || Gives
-------------------------------------------------------
Attribute | FAN_CONFIG_x_y | FAN_COMMAND_y || Value
----------------------------------------------++-------
fanX_target | ~PB_FAN_z_RPM | 0x0001 || 1
pwm1 | ~PB_FAN_z_RPM | 0x0064 || 255
pwmX_enable | ~PB_FAN_z_RPM | 0x0001 || 1
fanX_target | PB_FAN_z_RPM | 0x0001 || 1
pwm1 | PB_FAN_z_RPM | 0x0064 || 0
pwmX_enable | PB_FAN_z_RPM | 0x0001 || 1
And the write case:
Write | With || Sets
-------------+-------++----------------+---------------
Attribute | Value || FAN_CONFIG_x_y | FAN_COMMAND_x
-------------+-------++----------------+---------------
fanX_target | 1 || PB_FAN_z_RPM | 0x0001
pwmX | 255 || ~PB_FAN_z_RPM | 0x0064
pwmX_enable | 1 || ~PB_FAN_z_RPM | 0x0064
Also, the DIRECT mode scaling of some controllers is different between
RPM and PWM percent duty control modes, so PSC_PWM is introduced to
capture the necessary coefficients.
Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
v1 -> v2:
* Convert to using virtual registers
* Drop struct pmbus_fan_ctrl
* Introduce PSC_PWM
* Drop struct pmbus_coeffs
* Drop additional callbacks
drivers/hwmon/pmbus/pmbus.h | 19 ++++
drivers/hwmon/pmbus/pmbus_core.c | 215 +++++++++++++++++++++++++++++++++++----
2 files changed, 217 insertions(+), 17 deletions(-)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index bfcb13bae34b..226a37bd525f 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -190,6 +190,20 @@ enum pmbus_regs {
PMBUS_VIRT_VMON_UV_FAULT_LIMIT,
PMBUS_VIRT_VMON_OV_FAULT_LIMIT,
PMBUS_VIRT_STATUS_VMON,
+
+ /* Fan control */
+ PMBUS_VIRT_FAN_TARGET_1,
+ PMBUS_VIRT_FAN_TARGET_2,
+ PMBUS_VIRT_FAN_TARGET_3,
+ PMBUS_VIRT_FAN_TARGET_4,
+ PMBUS_VIRT_PWM_1,
+ PMBUS_VIRT_PWM_2,
+ PMBUS_VIRT_PWM_3,
+ PMBUS_VIRT_PWM_4,
+ PMBUS_VIRT_PWM_ENABLE_1,
+ PMBUS_VIRT_PWM_ENABLE_2,
+ PMBUS_VIRT_PWM_ENABLE_3,
+ PMBUS_VIRT_PWM_ENABLE_4,
};
/*
@@ -223,6 +237,8 @@ enum pmbus_regs {
#define PB_FAN_1_RPM BIT(6)
#define PB_FAN_1_INSTALLED BIT(7)
+enum pmbus_fan_mode { percent = 0, rpm };
+
/*
* STATUS_BYTE, STATUS_WORD (lower)
*/
@@ -313,6 +329,7 @@ enum pmbus_sensor_classes {
PSC_POWER,
PSC_TEMPERATURE,
PSC_FAN,
+ PSC_PWM,
PSC_NUM_CLASSES /* Number of power sensor classes */
};
@@ -413,6 +430,8 @@ int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg,
u8 value);
int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
u8 mask, u8 value);
+int pmbus_update_fan(struct i2c_client *client, int page, int id,
+ int config, int mask, int command);
void pmbus_clear_faults(struct i2c_client *client);
bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg);
bool pmbus_check_word_register(struct i2c_client *client, int page, int reg);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index ba59eaef2e07..712a8b6c4bd6 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -63,6 +63,7 @@ struct pmbus_sensor {
u16 reg; /* register */
enum pmbus_sensor_classes class; /* sensor class */
bool update; /* runtime sensor update needed */
+ bool convert; /* Whether or not to apply linear/vid/direct */
int data; /* Sensor data.
Negative if there was a read error */
};
@@ -118,6 +119,27 @@ struct pmbus_data {
u8 currpage;
};
+static const int pmbus_fan_rpm_mask[] = {
+ PB_FAN_1_RPM,
+ PB_FAN_2_RPM,
+ PB_FAN_1_RPM,
+ PB_FAN_2_RPM,
+};
+
+static const int pmbus_fan_config_registers[] = {
+ PMBUS_FAN_CONFIG_12,
+ PMBUS_FAN_CONFIG_12,
+ PMBUS_FAN_CONFIG_34,
+ PMBUS_FAN_CONFIG_34
+};
+
+static const int pmbus_fan_command_registers[] = {
+ PMBUS_FAN_COMMAND_1,
+ PMBUS_FAN_COMMAND_2,
+ PMBUS_FAN_COMMAND_3,
+ PMBUS_FAN_COMMAND_4,
+};
+
void pmbus_clear_cache(struct i2c_client *client)
{
struct pmbus_data *data = i2c_get_clientdata(client);
@@ -188,6 +210,29 @@ int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word)
}
EXPORT_SYMBOL_GPL(pmbus_write_word_data);
+int pmbus_update_fan(struct i2c_client *client, int page, int id,
+ int config, int mask, int command)
+{
+ int from, to;
+ int rv;
+
+ from = pmbus_read_byte_data(client, page,
+ pmbus_fan_config_registers[id]);
+ if (from < 0)
+ return from;
+
+ to = (from & ~mask) | (config & mask);
+
+ rv = pmbus_write_byte_data(client, page,
+ pmbus_fan_config_registers[id], to);
+ if (rv < 0)
+ return rv;
+
+ return pmbus_write_word_data(client, page,
+ pmbus_fan_command_registers[id], command);
+}
+EXPORT_SYMBOL_GPL(pmbus_update_fan);
+
/*
* _pmbus_write_word_data() is similar to pmbus_write_word_data(), but checks if
* a device specific mapping function exists and calls it if necessary.
@@ -197,15 +242,47 @@ static int _pmbus_write_word_data(struct i2c_client *client, int page, int reg,
{
struct pmbus_data *data = i2c_get_clientdata(client);
const struct pmbus_driver_info *info = data->info;
- int status;
+ int status = -ENODATA;
if (info->write_word_data) {
status = info->write_word_data(client, page, reg, word);
if (status != -ENODATA)
return status;
}
- if (reg >= PMBUS_VIRT_BASE)
- return -ENXIO;
+ if (status == -ENODATA && reg >= PMBUS_VIRT_BASE) {
+ int id, bit;
+
+ switch (reg) {
+ case PMBUS_VIRT_FAN_TARGET_1:
+ case PMBUS_VIRT_FAN_TARGET_2:
+ case PMBUS_VIRT_FAN_TARGET_3:
+ case PMBUS_VIRT_FAN_TARGET_4:
+ id = reg - PMBUS_VIRT_FAN_TARGET_1;
+ bit = pmbus_fan_rpm_mask[id];
+ status = pmbus_update_fan(client, page, id, bit, bit,
+ word);
+ break;
+ case PMBUS_VIRT_PWM_1:
+ case PMBUS_VIRT_PWM_2:
+ case PMBUS_VIRT_PWM_3:
+ case PMBUS_VIRT_PWM_4:
+ {
+ long command = word;
+
+ id = reg - PMBUS_VIRT_PWM_1;
+ bit = pmbus_fan_rpm_mask[id];
+ command *= 100;
+ command /= 255;
+ status = pmbus_update_fan(client, page, id, 0, bit,
+ command);
+ break;
+ }
+ default:
+ status = -ENXIO;
+ break;
+ }
+ return status;
+ }
return pmbus_write_word_data(client, page, reg, word);
}
@@ -221,6 +298,9 @@ int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg)
}
EXPORT_SYMBOL_GPL(pmbus_read_word_data);
+static int pmbus_get_fan_command(struct i2c_client *client, int page, int id,
+ enum pmbus_fan_mode mode);
+
/*
* _pmbus_read_word_data() is similar to pmbus_read_word_data(), but checks if
* a device specific mapping function exists and calls it if necessary.
@@ -229,15 +309,49 @@ static int _pmbus_read_word_data(struct i2c_client *client, int page, int reg)
{
struct pmbus_data *data = i2c_get_clientdata(client);
const struct pmbus_driver_info *info = data->info;
- int status;
+ int status = -ENODATA;
if (info->read_word_data) {
status = info->read_word_data(client, page, reg);
if (status != -ENODATA)
return status;
}
- if (reg >= PMBUS_VIRT_BASE)
- return -ENXIO;
+ if (status == -ENODATA && reg >= PMBUS_VIRT_BASE) {
+ int id;
+
+ switch (reg) {
+ case PMBUS_VIRT_FAN_TARGET_1:
+ case PMBUS_VIRT_FAN_TARGET_2:
+ case PMBUS_VIRT_FAN_TARGET_3:
+ case PMBUS_VIRT_FAN_TARGET_4:
+ id = reg - PMBUS_VIRT_FAN_TARGET_1;
+ status = pmbus_get_fan_command(client, page, id, rpm);
+ break;
+ case PMBUS_VIRT_PWM_1:
+ case PMBUS_VIRT_PWM_2:
+ case PMBUS_VIRT_PWM_3:
+ case PMBUS_VIRT_PWM_4:
+ {
+ long rv;
+
+ id = reg - PMBUS_VIRT_PWM_1;
+ rv = pmbus_get_fan_command(client, page, id, percent);
+ if (rv < 0)
+ return rv;
+
+ rv *= 255;
+ rv /= 100;
+
+ status = rv;
+ break;
+ }
+ default:
+ status = -ENXIO;
+ break;
+ }
+
+ return status;
+ }
return pmbus_read_word_data(client, page, reg);
}
@@ -304,6 +418,23 @@ static int _pmbus_read_byte_data(struct i2c_client *client, int page, int reg)
return pmbus_read_byte_data(client, page, reg);
}
+static int pmbus_get_fan_command(struct i2c_client *client, int page, int id,
+ enum pmbus_fan_mode mode)
+{
+ int config;
+
+ config = _pmbus_read_byte_data(client, page,
+ pmbus_fan_config_registers[id]);
+ if (config < 0)
+ return config;
+
+ if ((mode == rpm) != (!!(config & pmbus_fan_rpm_mask[id])))
+ return 0;
+
+ return _pmbus_read_word_data(client, page,
+ pmbus_fan_command_registers[id]);
+}
+
static void pmbus_clear_fault_page(struct i2c_client *client, int page)
{
_pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
@@ -489,7 +620,7 @@ static long pmbus_reg2data_direct(struct pmbus_data *data,
/* X = 1/m * (Y * 10^-R - b) */
R = -R;
/* scale result to milli-units for everything but fans */
- if (sensor->class != PSC_FAN) {
+ if (!(sensor->class == PSC_FAN || sensor->class == PSC_PWM)) {
R += 3;
b *= 1000;
}
@@ -539,6 +670,9 @@ static long pmbus_reg2data(struct pmbus_data *data, struct pmbus_sensor *sensor)
{
long val;
+ if (!sensor->convert)
+ return sensor->data;
+
switch (data->info->format[sensor->class]) {
case direct:
val = pmbus_reg2data_direct(data, sensor);
@@ -642,7 +776,7 @@ static u16 pmbus_data2reg_direct(struct pmbus_data *data,
}
/* Calculate Y = (m * X + b) * 10^R */
- if (sensor->class != PSC_FAN) {
+ if (!(sensor->class == PSC_FAN || sensor->class == PSC_PWM)) {
R -= 3; /* Adjust R and b for data in milli-units */
b *= 1000;
}
@@ -673,6 +807,9 @@ static u16 pmbus_data2reg(struct pmbus_data *data,
{
u16 regval;
+ if (!sensor->convert)
+ return val;
+
switch (data->info->format[sensor->class]) {
case direct:
regval = pmbus_data2reg_direct(data, sensor, val);
@@ -895,12 +1032,13 @@ static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data,
return NULL;
a = &sensor->attribute;
- snprintf(sensor->name, sizeof(sensor->name), "%s%d_%s",
- name, seq, type);
+ snprintf(sensor->name, sizeof(sensor->name), "%s%d%s%s",
+ name, seq, type ? "_" : "", type ? type : "");
sensor->page = page;
sensor->reg = reg;
sensor->class = class;
sensor->update = update;
+ sensor->convert = true;
pmbus_dev_attr_init(a, sensor->name,
readonly ? S_IRUGO : S_IRUGO | S_IWUSR,
pmbus_show_sensor, pmbus_set_sensor);
@@ -1558,13 +1696,6 @@ static const int pmbus_fan_registers[] = {
PMBUS_READ_FAN_SPEED_4
};
-static const int pmbus_fan_config_registers[] = {
- PMBUS_FAN_CONFIG_12,
- PMBUS_FAN_CONFIG_12,
- PMBUS_FAN_CONFIG_34,
- PMBUS_FAN_CONFIG_34
-};
-
static const int pmbus_fan_status_registers[] = {
PMBUS_STATUS_FAN_12,
PMBUS_STATUS_FAN_12,
@@ -1587,6 +1718,47 @@ static const u32 pmbus_fan_status_flags[] = {
};
/* Fans */
+static int pmbus_add_fan_ctrl(struct i2c_client *client,
+ struct pmbus_data *data, int index, int page, int id,
+ u8 config)
+{
+ struct pmbus_sensor *sensor;
+ int rv;
+
+ rv = _pmbus_read_word_data(client, page,
+ pmbus_fan_command_registers[id]);
+ if (rv < 0)
+ return rv;
+
+ sensor = pmbus_add_sensor(data, "fan", "target", index, page,
+ PMBUS_VIRT_FAN_TARGET_1 + id, PSC_FAN,
+ true, false);
+
+ if (!sensor)
+ return -ENOMEM;
+
+ if (!data->info->m[PSC_PWM])
+ return 0;
+
+ sensor = pmbus_add_sensor(data, "pwm", NULL, index, page,
+ PMBUS_VIRT_PWM_1 + id, PSC_PWM,
+ true, false);
+
+ if (!sensor)
+ return -ENOMEM;
+
+ sensor = pmbus_add_sensor(data, "pwm", "enable", index, page,
+ PMBUS_VIRT_PWM_ENABLE_1 + id, PSC_PWM,
+ true, false);
+
+ if (!sensor)
+ return -ENOMEM;
+
+ sensor->convert = false;
+
+ return 0;
+}
+
static int pmbus_add_fan_attributes(struct i2c_client *client,
struct pmbus_data *data)
{
@@ -1624,6 +1796,15 @@ static int pmbus_add_fan_attributes(struct i2c_client *client,
PSC_FAN, true, true) == NULL)
return -ENOMEM;
+ /* Fan control */
+ if (pmbus_check_word_register(client, page,
+ pmbus_fan_command_registers[f])) {
+ ret = pmbus_add_fan_ctrl(client, data, index,
+ page, f, regval);
+ if (ret < 0)
+ return ret;
+ }
+
/*
* Each fan status register covers multiple fans,
* so we have to do some magic.
--
2.11.0
More information about the openbmc
mailing list