diff options
Diffstat (limited to 'arch/arm/include/asm/arch-tegra/pwm.h')
-rw-r--r-- | arch/arm/include/asm/arch-tegra/pwm.h | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/arm/include/asm/arch-tegra/pwm.h b/arch/arm/include/asm/arch-tegra/pwm.h new file mode 100644 index 0000000..92dced4 --- /dev/null +++ b/arch/arm/include/asm/arch-tegra/pwm.h @@ -0,0 +1,60 @@ +/* + * Tegra pulse width frequency modulator definitions + * + * Copyright (c) 2011 The Chromium OS Authors. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __ASM_ARCH_TEGRA_PWM_H +#define __ASM_ARCH_TEGRA_PWM_H + +/* This is a single PWM channel */ +struct pwm_ctlr { + uint control; /* Control register */ + uint reserved[3]; /* Space space */ +}; + +#define PWM_NUM_CHANNELS 4 + +/* PWM_CONTROLLER_PWM_CSR_0/1/2/3_0 */ +#define PWM_ENABLE_SHIFT 31 +#define PWM_ENABLE_MASK (0x1 << PWM_ENABLE_SHIFT) + +#define PWM_WIDTH_SHIFT 16 +#define PWM_WIDTH_MASK (0x7FFF << PWM_WIDTH_SHIFT) + +#define PWM_DIVIDER_SHIFT 0 +#define PWM_DIVIDER_MASK (0x1FFF << PWM_DIVIDER_SHIFT) + +/** + * Program the PWM with the given parameters. + * + * @param channel PWM channel to update + * @param rate Clock rate to use for PWM, or 0 to leave alone + * @param pulse_width high pulse width: 0=always low, 1=1/256 pulse high, + * n = n/256 pulse high + * @param freq_divider frequency divider value (1 to use rate as is) + */ +void pwm_enable(unsigned channel, int rate, int pulse_width, int freq_divider); + +/** + * Request a pwm channel as referenced by a device tree node. + * + * This channel can then be passed to pwm_enable(). + * + * @param blob Device tree blob + * @param node Node containing reference to pwm + * @param prop_name Property name of pwm reference + * @return channel number, if ok, else -1 + */ +int pwm_request(const void *blob, int node, const char *prop_name); + +/** + * Set up the pwm controller, by looking it up in the fdt. + * + * @return 0 if ok, -1 if the device tree node was not found or invalid. + */ +int pwm_init(const void *blob); + +#endif /* __ASM_ARCH_TEGRA_PWM_H */ |