xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunTegra SoC PWFM controller
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunRequired properties:
4*4882a593Smuzhiyun- compatible: Must be:
5*4882a593Smuzhiyun  - "nvidia,tegra20-pwm": for Tegra20
6*4882a593Smuzhiyun  - "nvidia,tegra30-pwm", "nvidia,tegra20-pwm": for Tegra30
7*4882a593Smuzhiyun  - "nvidia,tegra114-pwm", "nvidia,tegra20-pwm": for Tegra114
8*4882a593Smuzhiyun  - "nvidia,tegra124-pwm", "nvidia,tegra20-pwm": for Tegra124
9*4882a593Smuzhiyun  - "nvidia,tegra132-pwm", "nvidia,tegra20-pwm": for Tegra132
10*4882a593Smuzhiyun  - "nvidia,tegra210-pwm", "nvidia,tegra20-pwm": for Tegra210
11*4882a593Smuzhiyun  - "nvidia,tegra186-pwm": for Tegra186
12*4882a593Smuzhiyun  - "nvidia,tegra194-pwm": for Tegra194
13*4882a593Smuzhiyun- reg: physical base address and length of the controller's registers
14*4882a593Smuzhiyun- #pwm-cells: should be 2. See pwm.yaml in this directory for a description of
15*4882a593Smuzhiyun  the cells format.
16*4882a593Smuzhiyun- clocks: Must contain one entry, for the module clock.
17*4882a593Smuzhiyun  See ../clocks/clock-bindings.txt for details.
18*4882a593Smuzhiyun- resets: Must contain an entry for each entry in reset-names.
19*4882a593Smuzhiyun  See ../reset/reset.txt for details.
20*4882a593Smuzhiyun- reset-names: Must include the following entries:
21*4882a593Smuzhiyun  - pwm
22*4882a593Smuzhiyun
23*4882a593SmuzhiyunOptional properties:
24*4882a593Smuzhiyun============================
25*4882a593SmuzhiyunIn some of the interface like PWM based regulator device, it is required
26*4882a593Smuzhiyunto configure the pins differently in different states, especially in suspend
27*4882a593Smuzhiyunstate of the system. The configuration of pin is provided via the pinctrl
28*4882a593SmuzhiyunDT node as detailed in the pinctrl DT binding document
29*4882a593Smuzhiyun	Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunThe PWM node will have following optional properties.
32*4882a593Smuzhiyunpinctrl-names:	Pin state names. Must be "default" and "sleep".
33*4882a593Smuzhiyunpinctrl-0:	phandle for the default/active state of pin configurations.
34*4882a593Smuzhiyunpinctrl-1:	phandle for the sleep state of pin configurations.
35*4882a593Smuzhiyun
36*4882a593SmuzhiyunExample:
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun	pwm: pwm@7000a000 {
39*4882a593Smuzhiyun		compatible = "nvidia,tegra20-pwm";
40*4882a593Smuzhiyun		reg = <0x7000a000 0x100>;
41*4882a593Smuzhiyun		#pwm-cells = <2>;
42*4882a593Smuzhiyun		clocks = <&tegra_car 17>;
43*4882a593Smuzhiyun		resets = <&tegra_car 17>;
44*4882a593Smuzhiyun		reset-names = "pwm";
45*4882a593Smuzhiyun	};
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun
48*4882a593SmuzhiyunExample with the pin configuration for suspend and resume:
49*4882a593Smuzhiyun=========================================================
50*4882a593SmuzhiyunSuppose pin PE7 (On Tegra210) interfaced with the regulator device and
51*4882a593Smuzhiyunit requires PWM output to be tristated when system enters suspend.
52*4882a593SmuzhiyunFollowing will be DT binding to achieve this:
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun#include <dt-bindings/pinctrl/pinctrl-tegra.h>
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun	pinmux@700008d4 {
57*4882a593Smuzhiyun		pwm_active_state: pwm_active_state {
58*4882a593Smuzhiyun                        pe7 {
59*4882a593Smuzhiyun                                nvidia,pins = "pe7";
60*4882a593Smuzhiyun                                nvidia,tristate = <TEGRA_PIN_DISABLE>;
61*4882a593Smuzhiyun			};
62*4882a593Smuzhiyun		};
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun		pwm_sleep_state: pwm_sleep_state {
65*4882a593Smuzhiyun                        pe7 {
66*4882a593Smuzhiyun                                nvidia,pins = "pe7";
67*4882a593Smuzhiyun                                nvidia,tristate = <TEGRA_PIN_ENABLE>;
68*4882a593Smuzhiyun			};
69*4882a593Smuzhiyun		};
70*4882a593Smuzhiyun	};
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun	pwm@7000a000 {
73*4882a593Smuzhiyun		/* Mandatory PWM properties */
74*4882a593Smuzhiyun		pinctrl-names = "default", "sleep";
75*4882a593Smuzhiyun		pinctrl-0 = <&pwm_active_state>;
76*4882a593Smuzhiyun		pinctrl-1 = <&pwm_sleep_state>;
77*4882a593Smuzhiyun	};
78