xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/pwm/pwm-sifive.yaml (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2*4882a593Smuzhiyun# Copyright (C) 2020 SiFive, Inc.
3*4882a593Smuzhiyun%YAML 1.2
4*4882a593Smuzhiyun---
5*4882a593Smuzhiyun$id: http://devicetree.org/schemas/pwm/pwm-sifive.yaml#
6*4882a593Smuzhiyun$schema: http://devicetree.org/meta-schemas/core.yaml#
7*4882a593Smuzhiyun
8*4882a593Smuzhiyuntitle: SiFive PWM controller
9*4882a593Smuzhiyun
10*4882a593Smuzhiyunmaintainers:
11*4882a593Smuzhiyun  - Yash Shah <yash.shah@sifive.com>
12*4882a593Smuzhiyun  - Sagar Kadam <sagar.kadam@sifive.com>
13*4882a593Smuzhiyun  - Paul Walmsley <paul.walmsley@sifive.com>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyundescription:
16*4882a593Smuzhiyun  Unlike most other PWM controllers, the SiFive PWM controller currently
17*4882a593Smuzhiyun  only supports one period for all channels in the PWM. All PWMs need to
18*4882a593Smuzhiyun  run at the same period. The period also has significant restrictions on
19*4882a593Smuzhiyun  the values it can achieve, which the driver rounds to the nearest
20*4882a593Smuzhiyun  achievable period. PWM RTL that corresponds to the IP block version
21*4882a593Smuzhiyun  numbers can be found here -
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun  https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/pwm
24*4882a593Smuzhiyun
25*4882a593Smuzhiyunproperties:
26*4882a593Smuzhiyun  compatible:
27*4882a593Smuzhiyun    items:
28*4882a593Smuzhiyun      - const: sifive,fu540-c000-pwm
29*4882a593Smuzhiyun      - const: sifive,pwm0
30*4882a593Smuzhiyun    description:
31*4882a593Smuzhiyun      Should be "sifive,<chip>-pwm" and "sifive,pwm<version>". Supported
32*4882a593Smuzhiyun      compatible strings are "sifive,fu540-c000-pwm" for the SiFive PWM v0
33*4882a593Smuzhiyun      as integrated onto the SiFive FU540 chip, and "sifive,pwm0" for the
34*4882a593Smuzhiyun      SiFive PWM v0 IP block with no chip integration tweaks.
35*4882a593Smuzhiyun      Please refer to sifive-blocks-ip-versioning.txt for details.
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun  reg:
38*4882a593Smuzhiyun    maxItems: 1
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun  clocks:
41*4882a593Smuzhiyun    maxItems: 1
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun  "#pwm-cells":
44*4882a593Smuzhiyun    const: 3
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun  interrupts:
47*4882a593Smuzhiyun    maxItems: 4
48*4882a593Smuzhiyun    description:
49*4882a593Smuzhiyun      Each PWM instance in FU540-C000 has 4 comparators. One interrupt per comparator.
50*4882a593Smuzhiyun
51*4882a593Smuzhiyunrequired:
52*4882a593Smuzhiyun  - compatible
53*4882a593Smuzhiyun  - reg
54*4882a593Smuzhiyun  - clocks
55*4882a593Smuzhiyun  - "#pwm-cells"
56*4882a593Smuzhiyun  - interrupts
57*4882a593Smuzhiyun
58*4882a593SmuzhiyunadditionalProperties: false
59*4882a593Smuzhiyun
60*4882a593Smuzhiyunexamples:
61*4882a593Smuzhiyun  - |
62*4882a593Smuzhiyun    pwm:  pwm@10020000 {
63*4882a593Smuzhiyun      compatible = "sifive,fu540-c000-pwm", "sifive,pwm0";
64*4882a593Smuzhiyun      reg = <0x10020000 0x1000>;
65*4882a593Smuzhiyun      clocks = <&tlclk>;
66*4882a593Smuzhiyun      interrupt-parent = <&plic>;
67*4882a593Smuzhiyun      interrupts = <42>, <43>, <44>, <45>;
68*4882a593Smuzhiyun      #pwm-cells = <3>;
69*4882a593Smuzhiyun    };
70