diff options
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/gpio/consumer.rst | 2 | ||||
| -rw-r--r-- | Documentation/driver-api/gpio/drivers-on-gpio.rst | 6 | ||||
| -rw-r--r-- | Documentation/driver-api/pwm.rst | 6 | ||||
| -rw-r--r-- | Documentation/driver-api/thermal/sysfs-api.rst | 12 | ||||
| -rw-r--r-- | Documentation/driver-api/vfio.rst | 2 |
5 files changed, 14 insertions, 14 deletions
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst index 22271c342d92..3366a991b4aa 100644 --- a/Documentation/driver-api/gpio/consumer.rst +++ b/Documentation/driver-api/gpio/consumer.rst @@ -12,7 +12,7 @@ Guidelines for GPIOs consumers Drivers that can't work without standard GPIO calls should have Kconfig entries that depend on GPIOLIB or select GPIOLIB. The functions that allow a driver to -obtain and use GPIOs are available by including the following file: +obtain and use GPIOs are available by including the following file:: #include <linux/gpio/consumer.h> diff --git a/Documentation/driver-api/gpio/drivers-on-gpio.rst b/Documentation/driver-api/gpio/drivers-on-gpio.rst index 41ec3cc72d32..af632d764ac6 100644 --- a/Documentation/driver-api/gpio/drivers-on-gpio.rst +++ b/Documentation/driver-api/gpio/drivers-on-gpio.rst @@ -96,6 +96,12 @@ hardware descriptions such as device tree or ACPI: way to pass the charging parameters from hardware descriptions such as the device tree. +- gpio-mux: drivers/mux/gpio.c is used for controlling a multiplexer using + n GPIO lines such that you can mux in 2^n different devices by activating + different GPIO lines. Often the GPIOs are on a SoC and the devices are + some SoC-external entities, such as different components on a PCB that + can be selectively enabled. + Apart from this there are special GPIO drivers in subsystems like MMC/SD to read card detect and write protect GPIO lines, and in the TTY serial subsystem to emulate MCTRL (modem control) signals CTS/RTS by using two GPIO lines. The diff --git a/Documentation/driver-api/pwm.rst b/Documentation/driver-api/pwm.rst index ab62f1bb0366..a7ca4f58305a 100644 --- a/Documentation/driver-api/pwm.rst +++ b/Documentation/driver-api/pwm.rst @@ -55,7 +55,11 @@ several parameter at once. For example, if you see pwm_config() and pwm_{enable,disable}() calls in the same function, this probably means you should switch to pwm_apply_state(). -The PWM user API also allows one to query the PWM state with pwm_get_state(). +The PWM user API also allows one to query the PWM state that was passed to the +last invocation of pwm_apply_state() using pwm_get_state(). Note this is +different to what the driver has actually implemented if the request cannot be +satisfied exactly with the hardware in use. There is currently no way for +consumers to get the actually implemented settings. In addition to the PWM state, the PWM API also exposes PWM arguments, which are the reference PWM config one should use on this PWM. diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index 29fdd817ddb0..4b638c14bc16 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -730,17 +730,7 @@ This function returns the thermal_instance corresponding to a given {thermal_zone, cooling_device, trip_point} combination. Returns NULL if such an instance does not exist. -4.3. thermal_notify_framework ------------------------------ - -This function handles the trip events from sensor drivers. It starts -throttling the cooling devices according to the policy configured. -For CRITICAL and HOT trip points, this notifies the respective drivers, -and does actual throttling for other trip points i.e ACTIVE and PASSIVE. -The throttling policy is based on the configured platform data; if no -platform data is provided, this uses the step_wise throttling policy. - -4.4. thermal_cdev_update +4.3. thermal_cdev_update ------------------------ This function serves as an arbitrator to set the state of a cooling diff --git a/Documentation/driver-api/vfio.rst b/Documentation/driver-api/vfio.rst index decc68cb8114..606eed8823ce 100644 --- a/Documentation/driver-api/vfio.rst +++ b/Documentation/driver-api/vfio.rst @@ -2,7 +2,7 @@ VFIO - "Virtual Function I/O" [1]_ ================================== -Many modern system now provide DMA and interrupt remapping facilities +Many modern systems now provide DMA and interrupt remapping facilities to help ensure I/O devices behave within the boundaries they've been allotted. This includes x86 hardware with AMD-Vi and Intel VT-d, POWER systems with Partitionable Endpoints (PEs) and embedded PowerPC |