Pmbus client drivers, if they want to use debugfs, should use the same
root directory as the pmbus debugfs entries are using. Therefore, export
the device dentry for the pmbus client.
Signed-off-by: Edward A. James <eajames@us.ibm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Some circumstances call for virtual pages, to expose multiple values
packed into an extended PMBus register in a manner non-compliant with
the PMBus standard. An example of this is the Maxim MAX31785 controller,
which extends the READ_FAN_SPEED_1 PMBus register from two to four bytes
to support tach readings for both rotors of a dual rotor fan. This extended
register contains two word-sized values, one reporting the rate of the
fastest rotor, the other the rate of the slowest. The concept of virtual
pages aids this situation by mapping the page number onto the value to be
selected from the vectored result.
We should not try to set virtual pages on the device as such a page
explicitly doesn't exist; add a flag so we can avoid doing so.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
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 configuration in 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 to
facilitate the necessary side-effects of each access:
1. PMBUS_VIRT_FAN_TARGET_x
2. PMBUS_VIRT_PWM_x
3. PMBUS_VIRT_PWM_ENABLE_x
Some complexity arises with the fanX_target and pwmX attributes both mapping
onto FAN_COMMAND_x: There is no general mapping between PWM percent duty and
RPM, so we can't display values in either attribute in terms of the other
(which in my mind is the intuitive, if impossible, behaviour). This problem
also affects the pwmX_enable attribute which allows userspace to switch between
full speed, manual PWM and a number of automatic control modes, possibly
including a switch to RPM behaviour (e.g. automatically adjusting PWM duty to
reach a RPM target, the behaviour of fanX_target).
The next most intuitive behaviour is for fanX_target and pwmX to simply be
independent, to retain their most recently set value even if that value is not
active on the hardware (due to switching to the alternative control mode). This
property of retaining the value independent of the hardware state has useful
results for both userspace and the kernel: Userspace always sees a sensible
value in the attribute (the last thing it was set to, as opposed to 0 or
receiving an error on read), and the kernel can use the attributes as a value
cache. This latter point eases the implementation of pwmX_enable, which can
look up the associated pmbus_sensor object, take its cached value and apply it
to hardware on changing control mode. This ensures we will not arbitrarily set
a PWM value as an RPM value or vice versa, and we can assume that the RPM or
PWM value set was sensible at least at some point in the past.
Finally, the DIRECT mode coefficients of some controllers is different between
RPM and PWM percent duty control modes, so PSC_PWM is introduced to capture the
necessary coefficients. As pmbus core had no PWM support previously PSC_FAN
continues to be used to capture the RPM DIRECT coefficients, but in order to
avoid falsely applying RPM scaling to PWM values I have introduced the
PMBUS_HAVE_PWM12 and PMB_BUS_HAVE_PWM34 feature bits. These feature bits allow
drivers to explicitly declare PWM support in order to have the attributes
exposed.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The pmbus core may call read/write word data functions with a page value
of -1, intending to perform the operation without setting the page.
However, the read/write word data functions accept only unsigned 8-bit
page numbers, and therefore cannot check for negative page number to
avoid setting the page. This results in setting the page number to 0xFF.
This may result in errors or undefined behavior of some devices
(specifically the ir35221, which allows the page to be set to 0xFF,
but some subsequent operations to read registers may fail).
Switch the pmbus_set_page page parameter to an integer and perform the
check for negative page there. Make read/write functions consistent in
accepting an integer page number parameter.
Signed-off-by: Edward A. James <eajames@us.ibm.com>
Fixes: cbcdec6202 ("hwmon: (pmbus): Access word data for STATUS_WORD")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The below lists of VOUT_MODE command readout with their related VID
protocols, Digital to Analog Converter steps:
- VR13.0 mode, 10-mV DAC - 0x24
- VR13.0 mode, 5-mV DAC - 0x27
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
pmbus_regulator_ops is not modified after initialized, so make it const.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The pmbus_regulator_ops is for voltage regulators, so explicitly set
regulator type for better readability.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add support for simple on/off control of each channel.
To add regulator support, the pmbus part driver needs to add
regulator_desc information and number of regulators to its
pmbus_driver_info struct.
regulator_desc can be declared using default macro for a
regulator (PMBUS_REGULATOR) that is in pmbus.h
The regulator_init_data can be initialized from either
platform data or the device tree.
Signed-off-by: Alan Tull <atull@opensource.altera.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
For PMBus chips, modifying one limit register may affect other limits.
Since limits are all cached in the PMBus core driver, related changes
are not reflected in reported limits.
Introduce function to clear the attribute cache. After calling this function,
the core pmbus driver re-reads all cached values.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Some PMBus chips support monitoring an additional non-standard voltage. While
this voltage can in many cases be supported by simulating an additional sensor
page, this does not work in all cases. Specifically, it is problematic if the
data format is linear and the voltage is reported in LINEAR11 format. Since
output voltages use LINEAR16, and the exponent for LINEAR16 data is chip-wide
and fixed, this can result in overflows.
To solve this problem, add support for an additional virtual input voltage,
call it 'vmon', and treat this voltage as input voltage (which, when the chip
supports linear data format, uses LINEAR11).
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add PMBUS_VIRT_READ_TEMP_AVG, PMBUS_VIRT_READ_TEMP2_AVG,
PMBUS_VIRT_READ_POUT_AVG, PMBUS_VIRT_READ_POUT_MAX,
and PMBUS_VIRT_RESET_POUT_HISTORY.
We'll need those for MAX34446.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Since devm_kzalloc() is now used to allocate driver memory, the client
driver remove function has no purpose other than to call pmbus_do_remove().
This means we can get rid of it by redefining pmbus_do_remove() to use the
same prototype, and pointing to it directly.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
At least one PMBus chip supports peak attributes for READ_TEMPERATURE2.
Add virtual registers to be able to report it to the user.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Driver remove functions have an error return value, but rarely return an error
in practice. If a driver does return an error from its remove function, the
driver won't be unloaded and is expected to stay alive.
pmbus_do_remove() is defined as returning an int, but always returns 0 (no
error). Calling code passes that return value on to high level driver
remove functions, but does not evaluate it and removes driver data even if
pmbus_do_remove() returned an error (which it in practice never does). Even if
this code could never cause a real problem, it is nevertheless conceptually
wrong.
To reduce confusion and simplify the code, change pmbus_do_remove() to be a void
function, and have PMBus client drivers always return zero in their driver
remove functions.
Reported-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Return values for functions reading/writing manufacturer specific registers are
poorly explained. Add comments to improve documentation.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
With virtual pages and to be able to handle more chips, it is necessary to
virtualise pmbus_write_byte().
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Most PMBus devices provide manufacturer specific commands to read low and/or
high peak values for some or all of its sensors.
To support providing those values as lowest/highest attributes to the user,
introduce virtual PMBus commands. Those commands reside outside the normal
command set and have to be implemented in device specific code, which map the
virtual commands to device specific commands.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Some PMBus chips have non-standard sensor registers. An easy way to
support such sensors is to introduce virtual pages and map the non-standard
registers into standard registers on an extra page.
For this to work, the code verifying if the configured number of pages exists
has to be removed. Since a wrong number of pages can only be configured in a
front-end driver, this should not have a practical impact since the resulting
errors should be found during development and testing.
Also, functions to read the chip status while checking if a command register
exists must be modified to no longer set the page register before reading the
status, since the physical page associated with the checked register may not
exist. This does not make a functional difference since the page was already set
when the attempt to read the register was made.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Some PMBus devices use non-standard registers for some of the sensors and/or
limits. To support such devices, add code to support reading and writing of word
size registers in device specific code.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
In VID mode, output voltages are measured and reported as VID values, and
have to be converted to voltages using VID conversion tables or functions.
Support is added for VR11 only at this time.
This patch enables support for PMBus devices supporting VID VR11 based output
voltage selection such as NCP4200 and NCP4208.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Since the number of PMBus drivers is getting large, move them into
directory drivers/hwmon/pmbus to improve readability and scalability.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>
Edward A. James