linux/drivers/pwm/pwm-raspberrypi-poe.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2021 Nicolas Saenz Julienne <[email protected]>
 * For more information on Raspberry Pi's PoE hat see:
 * https://www.raspberrypi.org/products/poe-hat/
 *
 * Limitations:
 *  - No disable bit, so a disabled PWM is simulated by duty_cycle 0
 *  - Only normal polarity
 *  - Fixed 12.5 kHz period
 *
 * The current period is completed when HW is reconfigured.
 */

#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>

#include <soc/bcm2835/raspberrypi-firmware.h>
#include <dt-bindings/pwm/raspberrypi,firmware-poe-pwm.h>

#define RPI_PWM_MAX_DUTY …
#define RPI_PWM_PERIOD_NS …

#define RPI_PWM_CUR_DUTY_REG …

struct raspberrypi_pwm { … };

struct raspberrypi_pwm_prop { … } __packed;

static inline
struct raspberrypi_pwm *raspberrypi_pwm_from_chip(struct pwm_chip *chip)
{ … }

static int raspberrypi_pwm_set_property(struct rpi_firmware *firmware,
					u32 reg, u32 val)
{ … }

static int raspberrypi_pwm_get_property(struct rpi_firmware *firmware,
					u32 reg, u32 *val)
{ … }

static int raspberrypi_pwm_get_state(struct pwm_chip *chip,
				     struct pwm_device *pwm,
				     struct pwm_state *state)
{ … }

static int raspberrypi_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
				 const struct pwm_state *state)
{ … }

static const struct pwm_ops raspberrypi_pwm_ops = …;

static int raspberrypi_pwm_probe(struct platform_device *pdev)
{ … }

static const struct of_device_id raspberrypi_pwm_of_match[] = …;
MODULE_DEVICE_TABLE(of, raspberrypi_pwm_of_match);

static struct platform_driver raspberrypi_pwm_driver = …;
module_platform_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;