linux/drivers/pwm/pwm-ep93xx.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] this program is distributed in the hope that
  it will be useful but without any warranty without even the implied
  warranty of merchantability or fitness for a particular purpose see
  the gnu general public license for more details

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] this program is distributed in the hope
  that it will be useful but without any warranty without even the
  implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

222 lines
5.4 KiB
C

// 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");