linux/drivers/pwm/pwm-ep93xx.c
Uwe Kleine-König f9a8ee8c8b pwm: Always allocate PWM chip base ID dynamically
Since commit 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip
base dynamically") all drivers use dynamic ID allocation explicitly. New
drivers are supposed to do the same, so remove support for driver
specified base IDs and drop all assignments in the low-level drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:53:00 +01:00

219 lines
5.3 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;
int ret;
ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
if (!ep93xx_pwm)
return -ENOMEM;
ep93xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
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.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");