1Parallel Port Devices 2===================== 3 4.. kernel-doc:: include/linux/parport.h 5 :internal: 6 7.. kernel-doc:: drivers/parport/ieee1284.c 8 :export: 9 10.. kernel-doc:: drivers/parport/share.c 11 :export: 12 13.. kernel-doc:: drivers/parport/daisy.c 14 :internal: 15 1616x50 UART Driver 17================= 18 19.. kernel-doc:: drivers/tty/serial/serial_core.c 20 :export: 21 22.. kernel-doc:: drivers/tty/serial/8250/8250_core.c 23 :export: 24 25Pulse-Width Modulation (PWM) 26============================ 27 28Pulse-width modulation is a modulation technique primarily used to 29control power supplied to electrical devices. 30 31The PWM framework provides an abstraction for providers and consumers of 32PWM signals. A controller that provides one or more PWM signals is 33registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers 34are expected to embed this structure in a driver-specific structure. 35This structure contains fields that describe a particular chip. 36 37A chip exposes one or more PWM signal sources, each of which exposed as 38a :c:type:`struct pwm_device <pwm_device>`. Operations can be 39performed on PWM devices to control the period, duty cycle, polarity and 40active state of the signal. 41 42Note that PWM devices are exclusive resources: they can always only be 43used by one consumer at a time. 44 45.. kernel-doc:: include/linux/pwm.h 46 :internal: 47 48.. kernel-doc:: drivers/pwm/core.c 49 :export: 50