385 lines
9.5 KiB
C
385 lines
9.5 KiB
C
|
/*
|
||
|
|
* Simple PWM driver for EP93XX
|
||
|
|
*
|
||
|
|
* (c) Copyright 2009 Matthieu Crapet <mcrapet@gmail.com>
|
||
|
|
* (c) Copyright 2009 H Hartley Sweeten <hsweeten@visionengravers.com>
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
*
|
||
|
|
* EP9307 has only one channel:
|
||
|
|
* - PWMOUT
|
||
|
|
*
|
||
|
|
* EP9301/02/12/15 have two channels:
|
||
|
|
* - PWMOUT
|
||
|
|
* - PWMOUT1 (alternate function for EGPIO14)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/platform_device.h>
|
||
|
|
#include <linux/clk.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <linux/io.h>
|
||
|
|
|
||
|
|
#include <mach/platform.h>
|
||
|
|
|
||
|
|
#define EP93XX_PWMx_TERM_COUNT 0x00
|
||
|
|
#define EP93XX_PWMx_DUTY_CYCLE 0x04
|
||
|
|
#define EP93XX_PWMx_ENABLE 0x08
|
||
|
|
#define EP93XX_PWMx_INVERT 0x0C
|
||
|
|
|
||
|
|
#define EP93XX_PWM_MAX_COUNT 0xFFFF
|
||
|
|
|
||
|
|
struct ep93xx_pwm {
|
||
|
|
void __iomem *mmio_base;
|
||
|
|
struct clk *clk;
|
||
|
|
u32 duty_percent;
|
||
|
|
};
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_writel(struct ep93xx_pwm *pwm,
|
||
|
|
unsigned int val, unsigned int off)
|
||
|
|
{
|
||
|
|
__raw_writel(val, pwm->mmio_base + off);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline unsigned int ep93xx_pwm_readl(struct ep93xx_pwm *pwm,
|
||
|
|
unsigned int off)
|
||
|
|
{
|
||
|
|
return __raw_readl(pwm->mmio_base + off);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_write_tc(struct ep93xx_pwm *pwm, u16 value)
|
||
|
|
{
|
||
|
|
ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_TERM_COUNT);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline u16 ep93xx_pwm_read_tc(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
return ep93xx_pwm_readl(pwm, EP93XX_PWMx_TERM_COUNT);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_write_dc(struct ep93xx_pwm *pwm, u16 value)
|
||
|
|
{
|
||
|
|
ep93xx_pwm_writel(pwm, value, EP93XX_PWMx_DUTY_CYCLE);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_enable(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_ENABLE);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_disable(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_ENABLE);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int ep93xx_pwm_is_enabled(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
return ep93xx_pwm_readl(pwm, EP93XX_PWMx_ENABLE) & 0x1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_invert(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
ep93xx_pwm_writel(pwm, 0x1, EP93XX_PWMx_INVERT);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void ep93xx_pwm_normal(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
ep93xx_pwm_writel(pwm, 0x0, EP93XX_PWMx_INVERT);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int ep93xx_pwm_is_inverted(struct ep93xx_pwm *pwm)
|
||
|
|
{
|
||
|
|
return ep93xx_pwm_readl(pwm, EP93XX_PWMx_INVERT) & 0x1;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* /sys/devices/platform/ep93xx-pwm.N
|
||
|
|
* /min_freq read-only minimum pwm output frequency
|
||
|
|
* /max_req read-only maximum pwm output frequency
|
||
|
|
* /freq read-write pwm output frequency (0 = disable output)
|
||
|
|
* /duty_percent read-write pwm duty cycle percent (1..99)
|
||
|
|
* /invert read-write invert pwm output
|
||
|
|
*/
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_get_min_freq(struct device *dev,
|
||
|
|
struct device_attribute *attr, char *buf)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
unsigned long rate = clk_get_rate(pwm->clk);
|
||
|
|
|
||
|
|
return sprintf(buf, "%ld\n", rate / (EP93XX_PWM_MAX_COUNT + 1));
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_get_max_freq(struct device *dev,
|
||
|
|
struct device_attribute *attr, char *buf)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
unsigned long rate = clk_get_rate(pwm->clk);
|
||
|
|
|
||
|
|
return sprintf(buf, "%ld\n", rate / 2);
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_get_freq(struct device *dev,
|
||
|
|
struct device_attribute *attr, char *buf)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
|
||
|
|
if (ep93xx_pwm_is_enabled(pwm)) {
|
||
|
|
unsigned long rate = clk_get_rate(pwm->clk);
|
||
|
|
u16 term = ep93xx_pwm_read_tc(pwm);
|
||
|
|
|
||
|
|
return sprintf(buf, "%ld\n", rate / (term + 1));
|
||
|
|
} else {
|
||
|
|
return sprintf(buf, "disabled\n");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_set_freq(struct device *dev,
|
||
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
long val;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = strict_strtol(buf, 10, &val);
|
||
|
|
if (err)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
if (val == 0) {
|
||
|
|
ep93xx_pwm_disable(pwm);
|
||
|
|
} else if (val <= (clk_get_rate(pwm->clk) / 2)) {
|
||
|
|
u32 term, duty;
|
||
|
|
|
||
|
|
val = (clk_get_rate(pwm->clk) / val) - 1;
|
||
|
|
if (val > EP93XX_PWM_MAX_COUNT)
|
||
|
|
val = EP93XX_PWM_MAX_COUNT;
|
||
|
|
if (val < 1)
|
||
|
|
val = 1;
|
||
|
|
|
||
|
|
term = ep93xx_pwm_read_tc(pwm);
|
||
|
|
duty = ((val + 1) * pwm->duty_percent / 100) - 1;
|
||
|
|
|
||
|
|
/* If pwm is running, order is important */
|
||
|
|
if (val > term) {
|
||
|
|
ep93xx_pwm_write_tc(pwm, val);
|
||
|
|
ep93xx_pwm_write_dc(pwm, duty);
|
||
|
|
} else {
|
||
|
|
ep93xx_pwm_write_dc(pwm, duty);
|
||
|
|
ep93xx_pwm_write_tc(pwm, val);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!ep93xx_pwm_is_enabled(pwm))
|
||
|
|
ep93xx_pwm_enable(pwm);
|
||
|
|
} else {
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_get_duty_percent(struct device *dev,
|
||
|
|
struct device_attribute *attr, char *buf)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
|
||
|
|
return sprintf(buf, "%d\n", pwm->duty_percent);
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_set_duty_percent(struct device *dev,
|
||
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
long val;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = strict_strtol(buf, 10, &val);
|
||
|
|
if (err)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
if (val > 0 && val < 100) {
|
||
|
|
u32 term = ep93xx_pwm_read_tc(pwm);
|
||
|
|
ep93xx_pwm_write_dc(pwm, ((term + 1) * val / 100) - 1);
|
||
|
|
pwm->duty_percent = val;
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_get_invert(struct device *dev,
|
||
|
|
struct device_attribute *attr, char *buf)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
|
||
|
|
return sprintf(buf, "%d\n", ep93xx_pwm_is_inverted(pwm));
|
||
|
|
}
|
||
|
|
|
||
|
|
static ssize_t ep93xx_pwm_set_invert(struct device *dev,
|
||
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
||
|
|
{
|
||
|
|
struct platform_device *pdev = to_platform_device(dev);
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
long val;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = strict_strtol(buf, 10, &val);
|
||
|
|
if (err)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
if (val == 0)
|
||
|
|
ep93xx_pwm_normal(pwm);
|
||
|
|
else if (val == 1)
|
||
|
|
ep93xx_pwm_invert(pwm);
|
||
|
|
else
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
static DEVICE_ATTR(min_freq, S_IRUGO, ep93xx_pwm_get_min_freq, NULL);
|
||
|
|
static DEVICE_ATTR(max_freq, S_IRUGO, ep93xx_pwm_get_max_freq, NULL);
|
||
|
|
static DEVICE_ATTR(freq, S_IWUSR | S_IRUGO,
|
||
|
|
ep93xx_pwm_get_freq, ep93xx_pwm_set_freq);
|
||
|
|
static DEVICE_ATTR(duty_percent, S_IWUSR | S_IRUGO,
|
||
|
|
ep93xx_pwm_get_duty_percent, ep93xx_pwm_set_duty_percent);
|
||
|
|
static DEVICE_ATTR(invert, S_IWUSR | S_IRUGO,
|
||
|
|
ep93xx_pwm_get_invert, ep93xx_pwm_set_invert);
|
||
|
|
|
||
|
|
static struct attribute *ep93xx_pwm_attrs[] = {
|
||
|
|
&dev_attr_min_freq.attr,
|
||
|
|
&dev_attr_max_freq.attr,
|
||
|
|
&dev_attr_freq.attr,
|
||
|
|
&dev_attr_duty_percent.attr,
|
||
|
|
&dev_attr_invert.attr,
|
||
|
|
NULL
|
||
|
|
};
|
||
|
|
|
||
|
|
static const struct attribute_group ep93xx_pwm_sysfs_files = {
|
||
|
|
.attrs = ep93xx_pwm_attrs,
|
||
|
|
};
|
||
|
|
|
||
|
|
static int __init ep93xx_pwm_probe(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
struct ep93xx_pwm *pwm;
|
||
|
|
struct resource *res;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = ep93xx_pwm_acquire_gpio(pdev);
|
||
|
|
if (err)
|
||
|
|
return err;
|
||
|
|
|
||
|
|
pwm = kzalloc(sizeof(struct ep93xx_pwm), GFP_KERNEL);
|
||
|
|
if (!pwm) {
|
||
|
|
err = -ENOMEM;
|
||
|
|
goto fail_no_mem;
|
||
|
|
}
|
||
|
|
|
||
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||
|
|
if (res == NULL) {
|
||
|
|
err = -ENXIO;
|
||
|
|
goto fail_no_mem_resource;
|
||
|
|
}
|
||
|
|
|
||
|
|
res = request_mem_region(res->start, resource_size(res), pdev->name);
|
||
|
|
if (res == NULL) {
|
||
|
|
err = -EBUSY;
|
||
|
|
goto fail_no_mem_resource;
|
||
|
|
}
|
||
|
|
|
||
|
|
pwm->mmio_base = ioremap(res->start, resource_size(res));
|
||
|
|
if (pwm->mmio_base == NULL) {
|
||
|
|
err = -ENXIO;
|
||
|
|
goto fail_no_ioremap;
|
||
|
|
}
|
||
|
|
|
||
|
|
err = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
|
||
|
|
if (err)
|
||
|
|
goto fail_no_sysfs;
|
||
|
|
|
||
|
|
pwm->clk = clk_get(&pdev->dev, "pwm_clk");
|
||
|
|
if (IS_ERR(pwm->clk)) {
|
||
|
|
err = PTR_ERR(pwm->clk);
|
||
|
|
goto fail_no_clk;
|
||
|
|
}
|
||
|
|
|
||
|
|
pwm->duty_percent = 50;
|
||
|
|
|
||
|
|
platform_set_drvdata(pdev, pwm);
|
||
|
|
|
||
|
|
/* disable pwm at startup. Avoids zero value. */
|
||
|
|
ep93xx_pwm_disable(pwm);
|
||
|
|
ep93xx_pwm_write_tc(pwm, EP93XX_PWM_MAX_COUNT);
|
||
|
|
ep93xx_pwm_write_dc(pwm, EP93XX_PWM_MAX_COUNT / 2);
|
||
|
|
|
||
|
|
clk_enable(pwm->clk);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
fail_no_clk:
|
||
|
|
sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
|
||
|
|
fail_no_sysfs:
|
||
|
|
iounmap(pwm->mmio_base);
|
||
|
|
fail_no_ioremap:
|
||
|
|
release_mem_region(res->start, resource_size(res));
|
||
|
|
fail_no_mem_resource:
|
||
|
|
kfree(pwm);
|
||
|
|
fail_no_mem:
|
||
|
|
ep93xx_pwm_release_gpio(pdev);
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int __exit ep93xx_pwm_remove(struct platform_device *pdev)
|
||
|
|
{
|
||
|
|
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
|
||
|
|
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||
|
|
|
||
|
|
ep93xx_pwm_disable(pwm);
|
||
|
|
clk_disable(pwm->clk);
|
||
|
|
clk_put(pwm->clk);
|
||
|
|
platform_set_drvdata(pdev, NULL);
|
||
|
|
sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
|
||
|
|
iounmap(pwm->mmio_base);
|
||
|
|
release_mem_region(res->start, resource_size(res));
|
||
|
|
kfree(pwm);
|
||
|
|
ep93xx_pwm_release_gpio(pdev);
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct platform_driver ep93xx_pwm_driver = {
|
||
|
|
.driver = {
|
||
|
|
.name = "ep93xx-pwm",
|
||
|
|
.owner = THIS_MODULE,
|
||
|
|
},
|
||
|
|
.remove = __exit_p(ep93xx_pwm_remove),
|
||
|
|
};
|
||
|
|
|
||
|
|
static int __init ep93xx_pwm_init(void)
|
||
|
|
{
|
||
|
|
return platform_driver_probe(&ep93xx_pwm_driver, ep93xx_pwm_probe);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __exit ep93xx_pwm_exit(void)
|
||
|
|
{
|
||
|
|
platform_driver_unregister(&ep93xx_pwm_driver);
|
||
|
|
}
|
||
|
|
|
||
|
|
module_init(ep93xx_pwm_init);
|
||
|
|
module_exit(ep93xx_pwm_exit);
|
||
|
|
|
||
|
|
MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>, "
|
||
|
|
"H Hartley Sweeten <hsweeten@visionengravers.com>");
|
||
|
|
MODULE_DESCRIPTION("EP93xx PWM driver");
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_ALIAS("platform:ep93xx-pwm");
|