| Jonathan Corbet | dcec3c8 | 2016-08-20 13:17:32 -0600 | [diff] [blame] | 1 | Parallel 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 | |
| 16 | 16x50 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 | |
| 25 | Pulse-Width Modulation (PWM) |
| 26 | ============================ |
| 27 | |
| 28 | Pulse-width modulation is a modulation technique primarily used to |
| 29 | control power supplied to electrical devices. |
| 30 | |
| 31 | The PWM framework provides an abstraction for providers and consumers of |
| 32 | PWM signals. A controller that provides one or more PWM signals is |
| 33 | registered as :c:type:`struct pwm_chip <pwm_chip>`. Providers |
| 34 | are expected to embed this structure in a driver-specific structure. |
| 35 | This structure contains fields that describe a particular chip. |
| 36 | |
| 37 | A chip exposes one or more PWM signal sources, each of which exposed as |
| 38 | a :c:type:`struct pwm_device <pwm_device>`. Operations can be |
| 39 | performed on PWM devices to control the period, duty cycle, polarity and |
| 40 | active state of the signal. |
| 41 | |
| 42 | Note that PWM devices are exclusive resources: they can always only be |
| 43 | used 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 | |