Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PWM framework driver for Cirrus Logic EP93xx
 *
 * Copyright (c) 2009        Matthieu Crapet <mcrapet@gmail.com>
 * Copyright (c) 2009, 2013  H Hartley Sweeten <hsweeten@visionengravers.com>
 *
 * EP9301/02 have only one channel:
 *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
 *
 * EP9307 has only one channel:
 *   platform device ep93xx-pwm.0 - PWMOUT
 *
 * EP9312/15 have two channels:
 *   platform device ep93xx-pwm.0 - PWMOUT
 *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
 */
 
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/pwm.h>
 
#include <asm/div64.h>
 
#include <linux/soc/cirrus/ep93xx.h>	/* for ep93xx_pwm_{acquire,release}_gpio() */
 
#define EP93XX_PWMx_TERM_COUNT	0x00
#define EP93XX_PWMx_DUTY_CYCLE	0x04
#define EP93XX_PWMx_ENABLE	0x08
#define EP93XX_PWMx_INVERT	0x0c
 
struct ep93xx_pwm {
<------>void __iomem *base;
<------>struct clk *clk;
<------>struct pwm_chip chip;
};
 
static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip)
{
<------>return container_of(chip, struct ep93xx_pwm, chip);
}
 
static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
<------>struct platform_device *pdev = to_platform_device(chip->dev);
 
<------>return ep93xx_pwm_acquire_gpio(pdev);
}
 
static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
<------>struct platform_device *pdev = to_platform_device(chip->dev);
 
<------>ep93xx_pwm_release_gpio(pdev);
}
 
static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
<------><------><------>     int duty_ns, int period_ns)
{
<------>struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
<------>void __iomem *base = ep93xx_pwm->base;
<------>unsigned long long c;
<------>unsigned long period_cycles;
<------>unsigned long duty_cycles;
<------>unsigned long term;
<------>int ret = 0;
 
<------>/*
<------> * The clock needs to be enabled to access the PWM registers.
<------> * Configuration can be changed at any time.
<------> */
<------>if (!pwm_is_enabled(pwm)) {
<------><------>ret = clk_enable(ep93xx_pwm->clk);
<------><------>if (ret)
<------><------><------>return ret;
<------>}
 
<------>c = clk_get_rate(ep93xx_pwm->clk);
<------>c *= period_ns;
<------>do_div(c, 1000000000);
<------>period_cycles = c;
 
<------>c = period_cycles;
<------>c *= duty_ns;
<------>do_div(c, period_ns);
<------>duty_cycles = c;
 
<------>if (period_cycles < 0x10000 && duty_cycles < 0x10000) {
<------><------>term = readw(base + EP93XX_PWMx_TERM_COUNT);
 
<------><------>/* Order is important if PWM is running */
<------><------>if (period_cycles > term) {
<------><------><------>writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
<------><------><------>writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
<------><------>} else {
<------><------><------>writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
<------><------><------>writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
<------><------>}
<------>} else {
<------><------>ret = -EINVAL;
<------>}
 
<------>if (!pwm_is_enabled(pwm))
<------><------>clk_disable(ep93xx_pwm->clk);
 
<------>return ret;
}
 
static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
<------><------><------>       enum pwm_polarity polarity)
{
<------>struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
<------>int ret;
 
<------>/*
<------> * The clock needs to be enabled to access the PWM registers.
<------> * Polarity can only be changed when the PWM is disabled.
<------> */
<------>ret = clk_enable(ep93xx_pwm->clk);
<------>if (ret)
<------><------>return ret;
 
<------>if (polarity == PWM_POLARITY_INVERSED)
<------><------>writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
<------>else
<------><------>writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
 
<------>clk_disable(ep93xx_pwm->clk);
 
<------>return 0;
}
 
static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
<------>struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
<------>int ret;
 
<------>ret = clk_enable(ep93xx_pwm->clk);
<------>if (ret)
<------><------>return ret;
 
<------>writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
 
<------>return 0;
}
 
static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
<------>struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
 
<------>writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
<------>clk_disable(ep93xx_pwm->clk);
}
 
static const struct pwm_ops ep93xx_pwm_ops = {
<------>.request = ep93xx_pwm_request,
<------>.free = ep93xx_pwm_free,
<------>.config = ep93xx_pwm_config,
<------>.set_polarity = ep93xx_pwm_polarity,
<------>.enable = ep93xx_pwm_enable,
<------>.disable = ep93xx_pwm_disable,
<------>.owner = THIS_MODULE,
};
 
static int ep93xx_pwm_probe(struct platform_device *pdev)
{
<------>struct ep93xx_pwm *ep93xx_pwm;
<------>struct resource *res;
<------>int ret;
 
<------>ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
<------>if (!ep93xx_pwm)
<------><------>return -ENOMEM;
 
<------>res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
<------>ep93xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);
<------>if (IS_ERR(ep93xx_pwm->base))
<------><------>return PTR_ERR(ep93xx_pwm->base);
 
<------>ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
<------>if (IS_ERR(ep93xx_pwm->clk))
<------><------>return PTR_ERR(ep93xx_pwm->clk);
 
<------>ep93xx_pwm->chip.dev = &pdev->dev;
<------>ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
<------>ep93xx_pwm->chip.base = -1;
<------>ep93xx_pwm->chip.npwm = 1;
 
<------>ret = pwmchip_add(&ep93xx_pwm->chip);
<------>if (ret < 0)
<------><------>return ret;
 
<------>platform_set_drvdata(pdev, ep93xx_pwm);
<------>return 0;
}
 
static int ep93xx_pwm_remove(struct platform_device *pdev)
{
<------>struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev);
 
<------>return pwmchip_remove(&ep93xx_pwm->chip);
}
 
static struct platform_driver ep93xx_pwm_driver = {
<------>.driver = {
<------><------>.name = "ep93xx-pwm",
<------>},
<------>.probe = ep93xx_pwm_probe,
<------>.remove = ep93xx_pwm_remove,
};
module_platform_driver(ep93xx_pwm_driver);
 
MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>");
MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_ALIAS("platform:ep93xx-pwm");
MODULE_LICENSE("GPL");