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pwm: add ep93xx PWM support

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Remove the non-standard EP93xx PWM driver in drivers/misc and add
a new driver for the PWM controllers on the EP93xx platform based
on the PWM framework.

These PWM controllers each support 1 PWM channel with programmable
duty cycle, frequency, and polarity inversion.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
H Hartley Sweeten 2013-10-15 18:40:03 -07:00 committed by Thierry Reding
parent 8f43e18e27
commit a230869817
6 changed files with 240 additions and 300 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
drivers/misc/Kconfig
View file

@ -381,19 +381,6 @@ config HMC6352
This driver provides support for the Honeywell HMC6352 compass,
providing configuration and heading data via sysfs.
config EP93XX_PWM
tristate "EP93xx PWM support"
depends on ARCH_EP93XX
help
This option enables device driver support for the PWM channels
on the Cirrus EP93xx processors. The EP9307 chip only has one
PWM channel all the others have two, the second channel is an
alternate function of the EGPIO14 pin. A sysfs interface is
provided to control the PWM channels.
To compile this driver as a module, choose M here: the module will
be called ep93xx_pwm.
config DS1682
tristate "Dallas DS1682 Total Elapsed Time Recorder with Alarm"
depends on I2C

1
drivers/misc/Makefile
View file

@ -33,7 +33,6 @@ obj-$(CONFIG_APDS9802ALS) += apds9802als.o
obj-$(CONFIG_ISL29003) += isl29003.o
obj-$(CONFIG_ISL29020) += isl29020.o
obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
obj-$(CONFIG_EP93XX_PWM) += ep93xx_pwm.o
obj-$(CONFIG_DS1682) += ds1682.o
obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o
obj-$(CONFIG_C2PORT) += c2port/

286
drivers/misc/ep93xx_pwm.c
View file

@ -1,286 +0,0 @@
/*
* 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/slab.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;
};
/*
* /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 (readl(pwm->mmio_base + EP93XX_PWMx_ENABLE) & 0x1) {
unsigned long rate = clk_get_rate(pwm->clk);
u16 term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
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 = kstrtol(buf, 10, &val);
if (err)
return -EINVAL;
if (val == 0) {
writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
} 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 = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
duty = ((val + 1) * pwm->duty_percent / 100) - 1;
/* If pwm is running, order is important */
if (val > term) {
writel(val, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
} else {
writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
writel(val, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
}
if (!readl(pwm->mmio_base + EP93XX_PWMx_ENABLE) & 0x1)
writel(0x1, pwm->mmio_base + EP93XX_PWMx_ENABLE);
} 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 = kstrtol(buf, 10, &val);
if (err)
return -EINVAL;
if (val > 0 && val < 100) {
u32 term = readl(pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
u32 duty = ((term + 1) * val / 100) - 1;
writel(duty, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
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);
int inverted = readl(pwm->mmio_base + EP93XX_PWMx_INVERT) & 0x1;
return sprintf(buf, "%d\n", inverted);
}
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 = kstrtol(buf, 10, &val);
if (err)
return -EINVAL;
if (val == 0)
writel(0x0, pwm->mmio_base + EP93XX_PWMx_INVERT);
else if (val == 1)
writel(0x1, pwm->mmio_base + EP93XX_PWMx_INVERT);
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 ep93xx_pwm_probe(struct platform_device *pdev)
{
struct ep93xx_pwm *pwm;
struct resource *res;
int ret;
pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
if (!pwm)
return -ENOMEM;
pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
if (IS_ERR(pwm->clk))
return PTR_ERR(pwm->clk);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pwm->mmio_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(pwm->mmio_base))
return PTR_ERR(pwm->mmio_base);
ret = ep93xx_pwm_acquire_gpio(pdev);
if (ret)
return ret;
ret = sysfs_create_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
if (ret) {
ep93xx_pwm_release_gpio(pdev);
return ret;
}
pwm->duty_percent = 50;
/* disable pwm at startup. Avoids zero value. */
writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
writel(EP93XX_PWM_MAX_COUNT, pwm->mmio_base + EP93XX_PWMx_TERM_COUNT);
writel(EP93XX_PWM_MAX_COUNT/2, pwm->mmio_base + EP93XX_PWMx_DUTY_CYCLE);
clk_enable(pwm->clk);
platform_set_drvdata(pdev, pwm);
return 0;
}
static int ep93xx_pwm_remove(struct platform_device *pdev)
{
struct ep93xx_pwm *pwm = platform_get_drvdata(pdev);
writel(0x0, pwm->mmio_base + EP93XX_PWMx_ENABLE);
clk_disable(pwm->clk);
sysfs_remove_group(&pdev->dev.kobj, &ep93xx_pwm_sysfs_files);
ep93xx_pwm_release_gpio(pdev);
return 0;
}
static struct platform_driver ep93xx_pwm_driver = {
.driver = {
.name = "ep93xx-pwm",
.owner = THIS_MODULE,
},
.probe = ep93xx_pwm_probe,
.remove = ep93xx_pwm_remove,
};
module_platform_driver(ep93xx_pwm_driver);
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");

9
drivers/pwm/Kconfig
View file

@ -62,6 +62,15 @@ config PWM_BFIN
To compile this driver as a module, choose M here: the module
will be called pwm-bfin.
config PWM_EP93XX
tristate "Cirrus Logic EP93xx PWM support"
depends on ARCH_EP93XX
help
Generic PWM framework driver for Cirrus Logic EP93xx.
To compile this driver as a module, choose M here: the module
will be called pwm-ep93xx.
config PWM_IMX
tristate "i.MX PWM support"
depends on ARCH_MXC

1
drivers/pwm/Makefile
View file

@ -3,6 +3,7 @@ obj-$(CONFIG_PWM_SYSFS) += sysfs.o
obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_EP93XX) += pwm-ep93xx.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o

230
drivers/pwm/pwm-ep93xx.c Normal file
View file

@ -0,0 +1,230 @@
/*
* 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)
*
* 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.
*/
#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 <mach/platform.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 (!test_bit(PWMF_ENABLED, &pwm->flags)) {
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 (!test_bit(PWMF_ENABLED, &pwm->flags))
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>, "
"H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_ALIAS("platform:ep93xx-pwm");
MODULE_LICENSE("GPL");