diff options
Diffstat (limited to 'include/linux/pinctrl/pinconf-generic.h')
| -rw-r--r-- | include/linux/pinctrl/pinconf-generic.h | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h index 6aa23809662..bf7e989abcb 100644 --- a/include/linux/pinctrl/pinconf-generic.h +++ b/include/linux/pinctrl/pinconf-generic.h @@ -29,12 +29,25 @@ * if for example some other pin is going to drive the signal connected * to it for a while. Pins used for input are usually always high * impedance. + * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it + * weakly drives the last value on a tristate bus, also known as a "bus + * holder", "bus keeper" or "repeater". This allows another device on the + * bus to change the value by driving the bus high or low and switching to + * tristate. The argument is ignored. * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high * impedance to VDD). If the argument is != 0 pull-up is enabled, - * if it is 0, pull-up is disabled. + * if it is 0, pull-up is total, i.e. the pin is connected to VDD. * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high * impedance to GROUND). If the argument is != 0 pull-down is enabled, - * if it is 0, pull-down is disabled. + * if it is 0, pull-down is total, i.e. the pin is connected to GROUND. + * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based + * on embedded knowledge of the controller hardware, like current mux + * function. The pull direction and possibly strength too will normally + * be decided completely inside the hardware block and not be readable + * from the kernel side. + * If the argument is != 0 pull up/down is enabled, if it is 0, the + * configuration is ignored. The proper way to disable it is to use + * @PIN_CONFIG_BIAS_DISABLE. * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and * low, this is the most typical case and is typically achieved with two * active transistors on the output. Setting this config will enable @@ -57,14 +70,14 @@ * setting pins to this mode. * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode, * which means it will wait for signals to settle when reading inputs. The - * argument gives the debounce time on a custom format. Setting the + * argument gives the debounce time in usecs. Setting the * argument to zero turns debouncing off. * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power * supplies, the argument to this parameter (on a custom format) tells * the driver which alternative power source to use. * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to - * this parameter (on a custom format) tells the driver which alternative - * slew rate to use. + * this parameter (on a custom format) tells the driver which alternative + * slew rate to use. * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power * operation, if several modes of operation are supported these can be * passed in the argument on a custom form, else just use argument 1 @@ -78,8 +91,10 @@ enum pin_config_param { PIN_CONFIG_BIAS_DISABLE, PIN_CONFIG_BIAS_HIGH_IMPEDANCE, + PIN_CONFIG_BIAS_BUS_HOLD, PIN_CONFIG_BIAS_PULL_UP, PIN_CONFIG_BIAS_PULL_DOWN, + PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, PIN_CONFIG_DRIVE_PUSH_PULL, PIN_CONFIG_DRIVE_OPEN_DRAIN, PIN_CONFIG_DRIVE_OPEN_SOURCE, |