2 * Tegra pulse width frequency modulator definitions
4 * Copyright (c) 2011 The Chromium OS Authors.
6 * SPDX-License-Identifier: GPL-2.0+
9 #ifndef __ASM_ARCH_TEGRA_PWM_H
10 #define __ASM_ARCH_TEGRA_PWM_H
12 /* This is a single PWM channel */
14 uint control; /* Control register */
15 uint reserved[3]; /* Space space */
18 #define PWM_NUM_CHANNELS 4
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)
24 #define PWM_WIDTH_SHIFT 16
25 #define PWM_WIDTH_MASK (0x7FFF << PWM_WIDTH_SHIFT)
27 #define PWM_DIVIDER_SHIFT 0
28 #define PWM_DIVIDER_MASK (0x1FFF << PWM_DIVIDER_SHIFT)
31 * Program the PWM with the given parameters.
33 * @param channel PWM channel to update
34 * @param rate Clock rate to use for PWM, or 0 to leave alone
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)
39 void pwm_enable(unsigned channel, int rate, int pulse_width, int freq_divider);
42 * Request a pwm channel as referenced by a device tree node.
44 * This channel can then be passed to pwm_enable().
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
51 int pwm_request(const void *blob, int node, const char *prop_name);
54 * Set up the pwm controller, by looking it up in the fdt.
56 * @return 0 if ok, -1 if the device tree node was not found or invalid.
58 int pwm_init(const void *blob);
60 #endif /* __ASM_ARCH_TEGRA_PWM_H */