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Commit | Line | Data |
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e1ae0d1f SG |
1 | /* |
2 | * Tegra pulse width frequency modulator definitions | |
3 | * | |
4 | * Copyright (c) 2011 The Chromium OS Authors. | |
e1ae0d1f | 5 | * |
1a459660 | 6 | * SPDX-License-Identifier: GPL-2.0+ |
e1ae0d1f SG |
7 | */ |
8 | ||
9 | #ifndef __ASM_ARCH_TEGRA_PWM_H | |
10 | #define __ASM_ARCH_TEGRA_PWM_H | |
11 | ||
12 | /* This is a single PWM channel */ | |
13 | struct pwm_ctlr { | |
14 | uint control; /* Control register */ | |
15 | uint reserved[3]; /* Space space */ | |
16 | }; | |
17 | ||
18 | #define PWM_NUM_CHANNELS 4 | |
19 | ||
20 | /* PWM_CONTROLLER_PWM_CSR_0/1/2/3_0 */ | |
21 | #define PWM_ENABLE_SHIFT 31 | |
22 | #define PWM_ENABLE_MASK (0x1 << PWM_ENABLE_SHIFT) | |
23 | ||
24 | #define PWM_WIDTH_SHIFT 16 | |
25 | #define PWM_WIDTH_MASK (0x7FFF << PWM_WIDTH_SHIFT) | |
26 | ||
27 | #define PWM_DIVIDER_SHIFT 0 | |
28 | #define PWM_DIVIDER_MASK (0x1FFF << PWM_DIVIDER_SHIFT) | |
29 | ||
30 | /** | |
31 | * Program the PWM with the given parameters. | |
32 | * | |
33 | * @param channel PWM channel to update | |
34 | * @param rate Clock rate to use for PWM | |
35 | * @param pulse_width high pulse width: 0=always low, 1=1/256 pulse high, | |
36 | * n = n/256 pulse high | |
37 | * @param freq_divider frequency divider value (1 to use rate as is) | |
38 | */ | |
39 | void pwm_enable(unsigned channel, int rate, int pulse_width, int freq_divider); | |
40 | ||
41 | /** | |
42 | * Request a pwm channel as referenced by a device tree node. | |
43 | * | |
44 | * This channel can then be passed to pwm_enable(). | |
45 | * | |
46 | * @param blob Device tree blob | |
47 | * @param node Node containing reference to pwm | |
48 | * @param prop_name Property name of pwm reference | |
49 | * @return channel number, if ok, else -1 | |
50 | */ | |
51 | int pwm_request(const void *blob, int node, const char *prop_name); | |
52 | ||
53 | /** | |
54 | * Set up the pwm controller, by looking it up in the fdt. | |
55 | * | |
56 | * @return 0 if ok, -1 if the device tree node was not found or invalid. | |
57 | */ | |
58 | int pwm_init(const void *blob); | |
59 | ||
60 | #endif /* __ASM_ARCH_TEGRA_PWM_H */ |