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rename target/linux/generic-2.6 to generic

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git-svn-id: svn://svn.openwrt.org/openwrt/trunk@21952 3c298f89-4303-0410-b956-a3cf2f4a3e73
This commit is contained in:
nbd
2010-06-26 20:42:58 +00:00
parent 7ec88f88f4
commit c5552ad039
1042 changed files with 1 additions and 1 deletions
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31
target/linux/generic/files/drivers/pwm/Kconfig Normal file
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#
# PWM infrastructure and devices
#
menuconfig GENERIC_PWM
tristate "PWM Support"
depends on SYSFS
help
This enables PWM support through the generic PWM library.
If unsure, say N.
if GENERIC_PWM
config ATMEL_PWM
tristate "Atmel AT32/AT91 PWM support"
depends on AVR32 || ARCH_AT91
help
This option enables device driver support for the PWMC
peripheral channels found on certain Atmel processors.
Pulse Width Modulation is used many for purposes, including
software controlled power-efficient backlights on LCD
displays, motor control, and waveform generation. If
unsure, say N.
config GPIO_PWM
tristate "PWM emulation using GPIO"
help
This option enables a single-channel PWM device using
a kernel interval timer and a GPIO pin. If unsure, say N.
endif

6
target/linux/generic/files/drivers/pwm/Makefile Normal file
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@@ -0,0 +1,6 @@
#
# Makefile for pwm devices
#
obj-y := pwm.o
obj-$(CONFIG_ATMEL_PWM) += atmel-pwm.o
obj-$(CONFIG_GPIO_PWM) += gpio.o

592
target/linux/generic/files/drivers/pwm/atmel-pwm.c Normal file
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/*
* drivers/pwm/atmel-pwm.c
*
* Copyright (C) 2010 Bill Gatliff <bgat@billgatliff.com>
* Copyright (C) 2007 David Brownell
*
* This program is free software; you may redistribute and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pwm/pwm.h>
enum {
/* registers common to the PWMC peripheral */
PWMC_MR = 0,
PWMC_ENA = 4,
PWMC_DIS = 8,
PWMC_SR = 0xc,
PWMC_IER = 0x10,
PWMC_IDR = 0x14,
PWMC_IMR = 0x18,
PWMC_ISR = 0x1c,
/* registers per each PWMC channel */
PWMC_CMR = 0,
PWMC_CDTY = 4,
PWMC_CPRD = 8,
PWMC_CCNT = 0xc,
PWMC_CUPD = 0x10,
/* how to find each channel */
PWMC_CHAN_BASE = 0x200,
PWMC_CHAN_STRIDE = 0x20,
/* CMR bits of interest */
PWMC_CMR_CPD = 10,
PWMC_CMR_CPOL = 9,
PWMC_CMR_CALG = 8,
PWMC_CMR_CPRE_MASK = 0xf,
};
struct atmel_pwm {
struct pwm_device pwm;
spinlock_t lock;
void __iomem *iobase;
struct clk *clk;
u32 *sync_mask;
int irq;
u32 ccnt_mask;
};
static inline struct atmel_pwm *to_atmel_pwm(const struct pwm_channel *p)
{
return container_of(p->pwm, struct atmel_pwm, pwm);
}
static inline void
pwmc_writel(const struct atmel_pwm *p,
unsigned offset, u32 val)
{
__raw_writel(val, p->iobase + offset);
}
static inline u32
pwmc_readl(const struct atmel_pwm *p,
unsigned offset)
{
return __raw_readl(p->iobase + offset);
}
static inline void
pwmc_chan_writel(const struct pwm_channel *p,
u32 offset, u32 val)
{
const struct atmel_pwm *ap = to_atmel_pwm(p);
if (PWMC_CMR == offset)
val &= ((1 << PWMC_CMR_CPD)
| (1 << PWMC_CMR_CPOL)
| (1 << PWMC_CMR_CALG)
| (PWMC_CMR_CPRE_MASK));
else
val &= ap->ccnt_mask;
pwmc_writel(ap, offset + PWMC_CHAN_BASE
+ (p->chan * PWMC_CHAN_STRIDE), val);
}
static inline u32
pwmc_chan_readl(const struct pwm_channel *p,
u32 offset)
{
const struct atmel_pwm *ap = to_atmel_pwm(p);
return pwmc_readl(ap, offset + PWMC_CHAN_BASE
+ (p->chan * PWMC_CHAN_STRIDE));
}
static inline int
__atmel_pwm_is_on(struct pwm_channel *p)
{
struct atmel_pwm *ap = to_atmel_pwm(p);
return (pwmc_readl(ap, PWMC_SR) & (1 << p->chan)) ? 1 : 0;
}
static inline void
__atmel_pwm_unsynchronize(struct pwm_channel *p,
struct pwm_channel *to_p)
{
const struct atmel_pwm *ap = to_atmel_pwm(p);
int wchan;
if (to_p) {
ap->sync_mask[p->chan] &= ~(1 << to_p->chan);
ap->sync_mask[to_p->chan] &= ~(1 << p->chan);
goto done;
}
ap->sync_mask[p->chan] = 0;
for (wchan = 0; wchan < ap->pwm.nchan; wchan++)
ap->sync_mask[wchan] &= ~(1 << p->chan);
done:
dev_dbg(p->pwm->dev, "sync_mask %x\n", ap->sync_mask[p->chan]);
}
static inline void
__atmel_pwm_synchronize(struct pwm_channel *p,
struct pwm_channel *to_p)
{
const struct atmel_pwm *ap = to_atmel_pwm(p);
if (!to_p)
return;
ap->sync_mask[p->chan] |= (1 << to_p->chan);
ap->sync_mask[to_p->chan] |= (1 << p->chan);
dev_dbg(p->pwm->dev, "sync_mask %x\n", ap->sync_mask[p->chan]);
}
static inline void
__atmel_pwm_stop(struct pwm_channel *p)
{
struct atmel_pwm *ap = to_atmel_pwm(p);
u32 chid = 1 << p->chan;
pwmc_writel(ap, PWMC_DIS, ap->sync_mask[p->chan] | chid);
}
static inline void
__atmel_pwm_start(struct pwm_channel *p)
{
struct atmel_pwm *ap = to_atmel_pwm(p);
u32 chid = 1 << p->chan;
pwmc_writel(ap, PWMC_ENA, ap->sync_mask[p->chan] | chid);
}
static int
atmel_pwm_synchronize(struct pwm_channel *p,
struct pwm_channel *to_p)
{
unsigned long flags;
spin_lock_irqsave(&p->lock, flags);
__atmel_pwm_synchronize(p, to_p);
spin_unlock_irqrestore(&p->lock, flags);
return 0;
}
static int
atmel_pwm_unsynchronize(struct pwm_channel *p,
struct pwm_channel *from_p)
{
unsigned long flags;
spin_lock_irqsave(&p->lock, flags);
__atmel_pwm_unsynchronize(p, from_p);
spin_unlock_irqrestore(&p->lock, flags);
return 0;
}
static inline int
__atmel_pwm_config_polarity(struct pwm_channel *p,
struct pwm_channel_config *c)
{
u32 cmr = pwmc_chan_readl(p, PWMC_CMR);
if (c->polarity)
cmr &= ~BIT(PWMC_CMR_CPOL);
else
cmr |= BIT(PWMC_CMR_CPOL);
pwmc_chan_writel(p, PWMC_CMR, cmr);
p->active_high = c->polarity ? 1 : 0;
dev_dbg(p->pwm->dev, "polarity %d\n", c->polarity);
return 0;
}
static inline int
__atmel_pwm_config_duty_ticks(struct pwm_channel *p,
struct pwm_channel_config *c)
{
u32 cmr, cprd, cpre, cdty;
cmr = pwmc_chan_readl(p, PWMC_CMR);
cprd = pwmc_chan_readl(p, PWMC_CPRD);
cpre = cmr & PWMC_CMR_CPRE_MASK;
cmr &= ~BIT(PWMC_CMR_CPD);
cdty = cprd - (c->duty_ticks >> cpre);
p->duty_ticks = c->duty_ticks;
if (__atmel_pwm_is_on(p)) {
pwmc_chan_writel(p, PWMC_CMR, cmr);
pwmc_chan_writel(p, PWMC_CUPD, cdty);
} else
pwmc_chan_writel(p, PWMC_CDTY, cdty);
dev_dbg(p->pwm->dev, "duty_ticks = %lu cprd = %x"
" cdty = %x cpre = %x\n", p->duty_ticks,
cprd, cdty, cpre);
return 0;
}
static inline int
__atmel_pwm_config_period_ticks(struct pwm_channel *p,
struct pwm_channel_config *c)
{
u32 cmr, cprd, cpre;
cpre = fls(c->period_ticks);
if (cpre < 16)
cpre = 0;
else {
cpre -= 15;
if (cpre > 10)
return -EINVAL;
}
cmr = pwmc_chan_readl(p, PWMC_CMR);
cmr &= ~PWMC_CMR_CPRE_MASK;
cmr |= cpre;
cprd = c->period_ticks >> cpre;
pwmc_chan_writel(p, PWMC_CMR, cmr);
pwmc_chan_writel(p, PWMC_CPRD, cprd);
p->period_ticks = c->period_ticks;
dev_dbg(p->pwm->dev, "period_ticks = %lu cprd = %x cpre = %x\n",
p->period_ticks, cprd, cpre);
return 0;
}
static int
atmel_pwm_config_nosleep(struct pwm_channel *p,
struct pwm_channel_config *c)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&p->lock, flags);
switch (c->config_mask) {
case PWM_CONFIG_DUTY_TICKS:
__atmel_pwm_config_duty_ticks(p, c);
break;
case PWM_CONFIG_STOP:
__atmel_pwm_stop(p);
break;
case PWM_CONFIG_START:
__atmel_pwm_start(p);
break;
case PWM_CONFIG_POLARITY:
__atmel_pwm_config_polarity(p, c);
break;
default:
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&p->lock, flags);
return ret;
}
static int
atmel_pwm_stop_sync(struct pwm_channel *p)
{
struct atmel_pwm *ap = container_of(p->pwm, struct atmel_pwm, pwm);
int ret;
int was_on = __atmel_pwm_is_on(p);
if (was_on) {
do {
init_completion(&p->complete);
set_bit(FLAG_STOP, &p->flags);
pwmc_writel(ap, PWMC_IER, 1 << p->chan);
dev_dbg(p->pwm->dev, "waiting on stop_sync completion...\n");
ret = wait_for_completion_interruptible(&p->complete);
dev_dbg(p->pwm->dev, "stop_sync complete (%d)\n", ret);
if (ret)
return ret;
} while (p->flags & BIT(FLAG_STOP));
}
return was_on;
}
static int
atmel_pwm_config(struct pwm_channel *p,
struct pwm_channel_config *c)
{
int was_on = 0;
if (p->pwm->config_nosleep) {
if (!p->pwm->config_nosleep(p, c))
return 0;
}
might_sleep();
dev_dbg(p->pwm->dev, "config_mask %x\n", c->config_mask);
was_on = atmel_pwm_stop_sync(p);
if (was_on < 0)
return was_on;
if (c->config_mask & PWM_CONFIG_PERIOD_TICKS) {
__atmel_pwm_config_period_ticks(p, c);
if (!(c->config_mask & PWM_CONFIG_DUTY_TICKS)) {
struct pwm_channel_config d = {
.config_mask = PWM_CONFIG_DUTY_TICKS,
.duty_ticks = p->duty_ticks,
};
__atmel_pwm_config_duty_ticks(p, &d);
}
}
if (c->config_mask & PWM_CONFIG_DUTY_TICKS)
__atmel_pwm_config_duty_ticks(p, c);
if (c->config_mask & PWM_CONFIG_POLARITY)
__atmel_pwm_config_polarity(p, c);
if ((c->config_mask & PWM_CONFIG_START)
|| (was_on && !(c->config_mask & PWM_CONFIG_STOP)))
__atmel_pwm_start(p);
return 0;
}
static void
__atmel_pwm_set_callback(struct pwm_channel *p,
pwm_callback_t callback)
{
struct atmel_pwm *ap = container_of(p->pwm, struct atmel_pwm, pwm);
p->callback = callback;
pwmc_writel(ap, p->callback ? PWMC_IER : PWMC_IDR, 1 << p->chan);
}
static int
atmel_pwm_set_callback(struct pwm_channel *p,
pwm_callback_t callback)
{
struct atmel_pwm *ap = to_atmel_pwm(p);
unsigned long flags;
spin_lock_irqsave(&ap->lock, flags);
__atmel_pwm_set_callback(p, callback);
spin_unlock_irqrestore(&ap->lock, flags);
return 0;
}
static int
atmel_pwm_request(struct pwm_channel *p)
{
struct atmel_pwm *ap = to_atmel_pwm(p);
unsigned long flags;
spin_lock_irqsave(&p->lock, flags);
clk_enable(ap->clk);
p->tick_hz = clk_get_rate(ap->clk);
__atmel_pwm_unsynchronize(p, NULL);
__atmel_pwm_stop(p);
spin_unlock_irqrestore(&p->lock, flags);
return 0;
}
static void
atmel_pwm_free(struct pwm_channel *p)
{
struct atmel_pwm *ap = to_atmel_pwm(p);
clk_disable(ap->clk);
}
static irqreturn_t
atmel_pwmc_irq(int irq, void *data)
{
struct atmel_pwm *ap = data;
struct pwm_channel *p;
u32 isr;
int chid;
unsigned long flags;
spin_lock_irqsave(&ap->lock, flags);
isr = pwmc_readl(ap, PWMC_ISR);
for (chid = 0; isr; chid++, isr >>= 1) {
p = &ap->pwm.channels[chid];
if (isr & 1) {
if (p->callback)
p->callback(p);
if (p->flags & BIT(FLAG_STOP)) {
__atmel_pwm_stop(p);
clear_bit(FLAG_STOP, &p->flags);
}
complete_all(&p->complete);
}
}
spin_unlock_irqrestore(&ap->lock, flags);
return IRQ_HANDLED;
}
static int __devinit
atmel_pwmc_probe(struct platform_device *pdev)
{
struct atmel_pwm *ap;
struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
int ret = 0;
ap = kzalloc(sizeof(*ap), GFP_KERNEL);
if (!ap) {
ret = -ENOMEM;
goto err_atmel_pwm_alloc;
}
spin_lock_init(&ap->lock);
platform_set_drvdata(pdev, ap);
ap->pwm.dev = &pdev->dev;
ap->pwm.bus_id = dev_name(&pdev->dev);
ap->pwm.nchan = 4; /* TODO: true only for SAM9263 and AP7000 */
ap->ccnt_mask = 0xffffUL; /* TODO: true only for SAM9263 */
ap->sync_mask = kzalloc(ap->pwm.nchan * sizeof(u32), GFP_KERNEL);
if (!ap->sync_mask) {
ret = -ENOMEM;
goto err_alloc_sync_masks;
}
ap->pwm.owner = THIS_MODULE;
ap->pwm.request = atmel_pwm_request;
ap->pwm.free = atmel_pwm_free;
ap->pwm.config_nosleep = atmel_pwm_config_nosleep;
ap->pwm.config = atmel_pwm_config;
ap->pwm.synchronize = atmel_pwm_synchronize;
ap->pwm.unsynchronize = atmel_pwm_unsynchronize;
ap->pwm.set_callback = atmel_pwm_set_callback;
ap->clk = clk_get(&pdev->dev, "pwm_clk");
if (PTR_ERR(ap->clk)) {
ret = -ENODEV;
goto err_clk_get;
}
ap->iobase = ioremap_nocache(r->start, r->end - r->start + 1);
if (!ap->iobase) {
ret = -ENODEV;
goto err_ioremap;
}
clk_enable(ap->clk);
pwmc_writel(ap, PWMC_DIS, -1);
pwmc_writel(ap, PWMC_IDR, -1);
clk_disable(ap->clk);
ap->irq = platform_get_irq(pdev, 0);
if (ap->irq != -ENXIO) {
ret = request_irq(ap->irq, atmel_pwmc_irq, 0,
ap->pwm.bus_id, ap);
if (ret)
goto err_request_irq;
}
ret = pwm_register(&ap->pwm);
if (ret)
goto err_pwm_register;
return 0;
err_pwm_register:
if (ap->irq != -ENXIO)
free_irq(ap->irq, ap);
err_request_irq:
iounmap(ap->iobase);
err_ioremap:
clk_put(ap->clk);
err_clk_get:
platform_set_drvdata(pdev, NULL);
err_alloc_sync_masks:
kfree(ap);
err_atmel_pwm_alloc:
return ret;
}
static int __devexit
atmel_pwmc_remove(struct platform_device *pdev)
{
struct atmel_pwm *ap = platform_get_drvdata(pdev);
int ret;
/* TODO: what can we do if this fails? */
ret = pwm_unregister(&ap->pwm);
clk_enable(ap->clk);
pwmc_writel(ap, PWMC_IDR, -1);
pwmc_writel(ap, PWMC_DIS, -1);
clk_disable(ap->clk);
if (ap->irq != -ENXIO)
free_irq(ap->irq, ap);
clk_put(ap->clk);
iounmap(ap->iobase);
kfree(ap);
return 0;
}
static struct platform_driver atmel_pwm_driver = {
.driver = {
.name = "atmel_pwmc",
.owner = THIS_MODULE,
},
.probe = atmel_pwmc_probe,
.remove = __devexit_p(atmel_pwmc_remove),
};
static int __init atmel_pwm_init(void)
{
return platform_driver_register(&atmel_pwm_driver);
}
module_init(atmel_pwm_init);
static void __exit atmel_pwm_exit(void)
{
platform_driver_unregister(&atmel_pwm_driver);
}
module_exit(atmel_pwm_exit);
MODULE_AUTHOR("Bill Gatliff <bgat@billgatliff.com>");
MODULE_DESCRIPTION("Driver for Atmel PWMC peripheral");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:atmel_pwmc");

298
target/linux/generic/files/drivers/pwm/gpio.c Normal file
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/*
* drivers/pwm/gpio.c
*
* Models a single-channel PWM device using a timer and a GPIO pin.
*
* Copyright (C) 2010 Bill Gatliff <bgat@billgatliff.com>
*
* This program is free software; you may redistribute and/or modify
* it under the terms of the GNU General Public License Version 2, as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/hrtimer.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/pwm/pwm.h>
struct gpio_pwm {
struct pwm_device pwm;
struct hrtimer timer;
struct work_struct work;
pwm_callback_t callback;
int gpio;
unsigned long polarity : 1;
unsigned long active : 1;
};
static inline struct gpio_pwm *to_gpio_pwm(const struct pwm_channel *p)
{
return container_of(p->pwm, struct gpio_pwm, pwm);
}
static void
gpio_pwm_work (struct work_struct *work)
{
struct gpio_pwm *gp = container_of(work, struct gpio_pwm, work);
if (gp->active)
gpio_direction_output(gp->gpio, gp->polarity ? 1 : 0);
else
gpio_direction_output(gp->gpio, gp->polarity ? 0 : 1);
}
static enum hrtimer_restart
gpio_pwm_timeout(struct hrtimer *t)
{
struct gpio_pwm *gp = container_of(t, struct gpio_pwm, timer);
ktime_t tnew;
if (unlikely(gp->pwm.channels[0].duty_ticks == 0))
gp->active = 0;
else if (unlikely(gp->pwm.channels[0].duty_ticks
== gp->pwm.channels[0].period_ticks))
gp->active = 1;
else
gp->active ^= 1;
if (gpio_cansleep(gp->gpio))
schedule_work(&gp->work);
else
gpio_pwm_work(&gp->work);
if (!gp->active && gp->pwm.channels[0].callback)
gp->pwm.channels[0].callback(&gp->pwm.channels[0]);
if (unlikely(!gp->active &&
(gp->pwm.channels[0].flags & BIT(FLAG_STOP)))) {
clear_bit(FLAG_STOP, &gp->pwm.channels[0].flags);
complete_all(&gp->pwm.channels[0].complete);
return HRTIMER_NORESTART;
}
if (gp->active)
tnew = ktime_set(0, gp->pwm.channels[0].duty_ticks);
else
tnew = ktime_set(0, gp->pwm.channels[0].period_ticks
- gp->pwm.channels[0].duty_ticks);
hrtimer_start(&gp->timer, tnew, HRTIMER_MODE_REL);
return HRTIMER_NORESTART;
}
static void gpio_pwm_start(struct pwm_channel *p)
{
struct gpio_pwm *gp = to_gpio_pwm(p);
gp->active = 0;
gpio_pwm_timeout(&gp->timer);
}
static int
gpio_pwm_config_nosleep(struct pwm_channel *p,
struct pwm_channel_config *c)
{
struct gpio_pwm *gp = to_gpio_pwm(p);
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&p->lock, flags);
switch (c->config_mask) {
case PWM_CONFIG_DUTY_TICKS:
p->duty_ticks = c->duty_ticks;
break;
case PWM_CONFIG_START:
if (!hrtimer_active(&gp->timer)) {
gpio_pwm_start(p);
}
break;
default:
ret = -EINVAL;
break;
}
spin_unlock_irqrestore(&p->lock, flags);
return ret;
}
static int
gpio_pwm_stop_sync(struct pwm_channel *p)
{
struct gpio_pwm *gp = to_gpio_pwm(p);
int ret;
int was_on = hrtimer_active(&gp->timer);
if (was_on) {
do {
init_completion(&p->complete);
set_bit(FLAG_STOP, &p->flags);
ret = wait_for_completion_interruptible(&p->complete);
if (ret)
return ret;
} while (p->flags & BIT(FLAG_STOP));
}
return was_on;
}
static int
gpio_pwm_config(struct pwm_channel *p,
struct pwm_channel_config *c)
{
struct gpio_pwm *gp = to_gpio_pwm(p);
int was_on = 0;
if (p->pwm->config_nosleep) {
if (!p->pwm->config_nosleep(p, c))
return 0;
}
might_sleep();
was_on = gpio_pwm_stop_sync(p);
if (was_on < 0)
return was_on;
if (c->config_mask & PWM_CONFIG_PERIOD_TICKS)
p->period_ticks = c->period_ticks;
if (c->config_mask & PWM_CONFIG_DUTY_TICKS)
p->duty_ticks = c->duty_ticks;
if (c->config_mask & PWM_CONFIG_POLARITY) {
gp->polarity = c->polarity ? 1 : 0;
p->active_high = gp->polarity;
}
if ((c->config_mask & PWM_CONFIG_START)
|| (was_on && !(c->config_mask & PWM_CONFIG_STOP)))
gpio_pwm_start(p);
return 0;
}
static int
gpio_pwm_set_callback(struct pwm_channel *p,
pwm_callback_t callback)
{
struct gpio_pwm *gp = to_gpio_pwm(p);
gp->callback = callback;
return 0;
}
static int
gpio_pwm_request(struct pwm_channel *p)
{
p->tick_hz = 1000000000UL;
return 0;
}
static int __devinit
gpio_pwm_probe(struct platform_device *pdev)
{
struct gpio_pwm *gp;
struct gpio_pwm_platform_data *gpd = pdev->dev.platform_data;
int ret = 0;
/* TODO: create configfs entries, so users can assign GPIOs to
* PWMs at runtime instead of creating a platform_device
* specification and rebuilding their kernel */
if (!gpd || gpio_request(gpd->gpio, dev_name(&pdev->dev)))
return -EINVAL;
gp = kzalloc(sizeof(*gp), GFP_KERNEL);
if (!gp) {
ret = -ENOMEM;
goto err_alloc;
}
platform_set_drvdata(pdev, gp);
gp->pwm.dev = &pdev->dev;
gp->pwm.bus_id = dev_name(&pdev->dev);
gp->pwm.nchan = 1;
gp->gpio = gpd->gpio;
INIT_WORK(&gp->work, gpio_pwm_work);
hrtimer_init(&gp->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
gp->timer.function = gpio_pwm_timeout;
gp->pwm.owner = THIS_MODULE;
gp->pwm.config_nosleep = gpio_pwm_config_nosleep;
gp->pwm.config = gpio_pwm_config;
gp->pwm.request = gpio_pwm_request;
gp->pwm.set_callback = gpio_pwm_set_callback;
ret = pwm_register(&gp->pwm);
if (ret)
goto err_pwm_register;
return 0;
err_pwm_register:
platform_set_drvdata(pdev, 0);
kfree(gp);
err_alloc:
return ret;
}
static int __devexit
gpio_pwm_remove(struct platform_device *pdev)
{
struct gpio_pwm *gp = platform_get_drvdata(pdev);
int ret;
ret = pwm_unregister(&gp->pwm);
hrtimer_cancel(&gp->timer);
cancel_work_sync(&gp->work);
platform_set_drvdata(pdev, 0);
kfree(gp);
return 0;
}
static struct platform_driver gpio_pwm_driver = {
.driver = {
.name = "gpio_pwm",
.owner = THIS_MODULE,
},
.probe = gpio_pwm_probe,
.remove = __devexit_p(gpio_pwm_remove),
};
static int __init gpio_pwm_init(void)
{
return platform_driver_register(&gpio_pwm_driver);
}
module_init(gpio_pwm_init);
static void __exit gpio_pwm_exit(void)
{
platform_driver_unregister(&gpio_pwm_driver);
}
module_exit(gpio_pwm_exit);
MODULE_AUTHOR("Bill Gatliff <bgat@billgatliff.com>");
MODULE_DESCRIPTION("PWM output using GPIO and a high-resolution timer");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio_pwm");

643
target/linux/generic/files/drivers/pwm/pwm.c Normal file
View File

@@ -0,0 +1,643 @@
/*
* drivers/pwm/pwm.c
*
* Copyright (C) 2010 Bill Gatliff <bgat@billgatliff.com>
*
* This program is free software; you may redistribute and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/completion.h>
#include <linux/workqueue.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/slab.h> /*kcalloc, kfree since 2.6.34 */
#include <linux/pwm/pwm.h>
static int __pwm_create_sysfs(struct pwm_device *pwm);
static const char *REQUEST_SYSFS = "sysfs";
static LIST_HEAD(pwm_device_list);
static DEFINE_MUTEX(device_list_mutex);
static struct class pwm_class;
static struct workqueue_struct *pwm_handler_workqueue;
int pwm_register(struct pwm_device *pwm)
{
struct pwm_channel *p;
int wchan;
int ret;
spin_lock_init(&pwm->list_lock);
p = kcalloc(pwm->nchan, sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
for (wchan = 0; wchan < pwm->nchan; wchan++) {
spin_lock_init(&p[wchan].lock);
init_completion(&p[wchan].complete);
p[wchan].chan = wchan;
p[wchan].pwm = pwm;
}
pwm->channels = p;
mutex_lock(&device_list_mutex);
list_add_tail(&pwm->list, &pwm_device_list);
ret = __pwm_create_sysfs(pwm);
if (ret) {
mutex_unlock(&device_list_mutex);
goto err_create_sysfs;
}
mutex_unlock(&device_list_mutex);
dev_info(pwm->dev, "%d channel%s\n", pwm->nchan,
pwm->nchan > 1 ? "s" : "");
return 0;
err_create_sysfs:
kfree(p);
return ret;
}
EXPORT_SYMBOL(pwm_register);
static int __match_device(struct device *dev, void *data)
{
return dev_get_drvdata(dev) == data;
}
int pwm_unregister(struct pwm_device *pwm)
{
int wchan;
struct device *dev;
mutex_lock(&device_list_mutex);
for (wchan = 0; wchan < pwm->nchan; wchan++) {
if (pwm->channels[wchan].flags & BIT(FLAG_REQUESTED)) {
mutex_unlock(&device_list_mutex);
return -EBUSY;
}
}
for (wchan = 0; wchan < pwm->nchan; wchan++) {
dev = class_find_device(&pwm_class, NULL,
&pwm->channels[wchan],
__match_device);
if (dev) {
put_device(dev);
device_unregister(dev);
}
}
kfree(pwm->channels);
list_del(&pwm->list);
mutex_unlock(&device_list_mutex);
return 0;
}
EXPORT_SYMBOL(pwm_unregister);
static struct pwm_device *
__pwm_find_device(const char *bus_id)
{
struct pwm_device *p;
list_for_each_entry(p, &pwm_device_list, list) {
if (!strcmp(bus_id, p->bus_id))
return p;
}
return NULL;
}
static int
__pwm_request_channel(struct pwm_channel *p,
const char *requester)
{
int ret;
if (test_and_set_bit(FLAG_REQUESTED, &p->flags))
return -EBUSY;
if (p->pwm->request) {
ret = p->pwm->request(p);
if (ret) {
clear_bit(FLAG_REQUESTED, &p->flags);
return ret;
}
}
p->requester = requester;
if (!strcmp(requester, REQUEST_SYSFS))
p->pid = current->pid;
return 0;
}
struct pwm_channel *
pwm_request(const char *bus_id,
int chan,
const char *requester)
{
struct pwm_device *p;
int ret;
mutex_lock(&device_list_mutex);
p = __pwm_find_device(bus_id);
if (!p || chan >= p->nchan)
goto err_no_device;
if (!try_module_get(p->owner))
goto err_module_get_failed;
ret = __pwm_request_channel(&p->channels[chan], requester);
if (ret)
goto err_request_failed;
mutex_unlock(&device_list_mutex);
return &p->channels[chan];
err_request_failed:
module_put(p->owner);
err_module_get_failed:
err_no_device:
mutex_unlock(&device_list_mutex);
return NULL;
}
EXPORT_SYMBOL(pwm_request);
void pwm_free(struct pwm_channel *p)
{
mutex_lock(&device_list_mutex);
if (!test_and_clear_bit(FLAG_REQUESTED, &p->flags))
goto done;
pwm_stop(p);
pwm_unsynchronize(p, NULL);
pwm_set_handler(p, NULL, NULL);
if (p->pwm->free)
p->pwm->free(p);
module_put(p->pwm->owner);
done:
mutex_unlock(&device_list_mutex);
}
EXPORT_SYMBOL(pwm_free);
unsigned long pwm_ns_to_ticks(struct pwm_channel *p,
unsigned long nsecs)
{
unsigned long long ticks;
ticks = nsecs;
ticks *= p->tick_hz;
do_div(ticks, 1000000000);
return ticks;
}
EXPORT_SYMBOL(pwm_ns_to_ticks);
unsigned long pwm_ticks_to_ns(struct pwm_channel *p,
unsigned long ticks)
{
unsigned long long ns;
if (!p->tick_hz)
return 0;
ns = ticks;
ns *= 1000000000UL;
do_div(ns, p->tick_hz);
return ns;
}
EXPORT_SYMBOL(pwm_ticks_to_ns);
static void
pwm_config_ns_to_ticks(struct pwm_channel *p,
struct pwm_channel_config *c)
{
if (c->config_mask & PWM_CONFIG_PERIOD_NS) {
c->period_ticks = pwm_ns_to_ticks(p, c->period_ns);
c->config_mask &= ~PWM_CONFIG_PERIOD_NS;
c->config_mask |= PWM_CONFIG_PERIOD_TICKS;
}
if (c->config_mask & PWM_CONFIG_DUTY_NS) {
c->duty_ticks = pwm_ns_to_ticks(p, c->duty_ns);
c->config_mask &= ~PWM_CONFIG_DUTY_NS;
c->config_mask |= PWM_CONFIG_DUTY_TICKS;
}
}
static void
pwm_config_percent_to_ticks(struct pwm_channel *p,
struct pwm_channel_config *c)
{
if (c->config_mask & PWM_CONFIG_DUTY_PERCENT) {
if (c->config_mask & PWM_CONFIG_PERIOD_TICKS)
c->duty_ticks = c->period_ticks;
else
c->duty_ticks = p->period_ticks;
c->duty_ticks *= c->duty_percent;
c->duty_ticks /= 100;
c->config_mask &= ~PWM_CONFIG_DUTY_PERCENT;
c->config_mask |= PWM_CONFIG_DUTY_TICKS;
}
}
int pwm_config_nosleep(struct pwm_channel *p,
struct pwm_channel_config *c)
{
if (!p->pwm->config_nosleep)
return -EINVAL;
pwm_config_ns_to_ticks(p, c);
pwm_config_percent_to_ticks(p, c);
return p->pwm->config_nosleep(p, c);
}
EXPORT_SYMBOL(pwm_config_nosleep);
int pwm_config(struct pwm_channel *p,
struct pwm_channel_config *c)
{
int ret = 0;
if (unlikely(!p->pwm->config))
return -EINVAL;
pwm_config_ns_to_ticks(p, c);
pwm_config_percent_to_ticks(p, c);
switch (c->config_mask & (PWM_CONFIG_PERIOD_TICKS
| PWM_CONFIG_DUTY_TICKS)) {
case PWM_CONFIG_PERIOD_TICKS:
if (p->duty_ticks > c->period_ticks) {
ret = -EINVAL;
goto err;
}
break;
case PWM_CONFIG_DUTY_TICKS:
if (p->period_ticks < c->duty_ticks) {
ret = -EINVAL;
goto err;
}
break;
case PWM_CONFIG_DUTY_TICKS | PWM_CONFIG_PERIOD_TICKS:
if (c->duty_ticks > c->period_ticks) {
ret = -EINVAL;
goto err;
}
break;
default:
break;
}
err:
dev_dbg(p->pwm->dev, "%s: config_mask %d period_ticks %lu duty_ticks %lu"
" polarity %d duty_ns %lu period_ns %lu duty_percent %d\n",
__func__, c->config_mask, c->period_ticks, c->duty_ticks,
c->polarity, c->duty_ns, c->period_ns, c->duty_percent);
if (ret)
return ret;
return p->pwm->config(p, c);
}
EXPORT_SYMBOL(pwm_config);
int pwm_set_period_ns(struct pwm_channel *p,
unsigned long period_ns)
{
struct pwm_channel_config c = {
.config_mask = PWM_CONFIG_PERIOD_TICKS,
.period_ticks = pwm_ns_to_ticks(p, period_ns),
};
return pwm_config(p, &c);
}
EXPORT_SYMBOL(pwm_set_period_ns);
unsigned long pwm_get_period_ns(struct pwm_channel *p)
{
return pwm_ticks_to_ns(p, p->period_ticks);
}
EXPORT_SYMBOL(pwm_get_period_ns);
int pwm_set_duty_ns(struct pwm_channel *p,
unsigned long duty_ns)
{
struct pwm_channel_config c = {
.config_mask = PWM_CONFIG_DUTY_TICKS,
.duty_ticks = pwm_ns_to_ticks(p, duty_ns),
};
return pwm_config(p, &c);
}
EXPORT_SYMBOL(pwm_set_duty_ns);
unsigned long pwm_get_duty_ns(struct pwm_channel *p)
{
return pwm_ticks_to_ns(p, p->duty_ticks);
}
EXPORT_SYMBOL(pwm_get_duty_ns);
int pwm_set_duty_percent(struct pwm_channel *p,
int percent)
{
struct pwm_channel_config c = {
.config_mask = PWM_CONFIG_DUTY_PERCENT,
.duty_percent = percent,
};
return pwm_config(p, &c);
}
EXPORT_SYMBOL(pwm_set_duty_percent);
int pwm_set_polarity(struct pwm_channel *p,
int active_high)
{
struct pwm_channel_config c = {
.config_mask = PWM_CONFIG_POLARITY,
.polarity = active_high,
};
return pwm_config(p, &c);
}
EXPORT_SYMBOL(pwm_set_polarity);
int pwm_start(struct pwm_channel *p)
{
struct pwm_channel_config c = {
.config_mask = PWM_CONFIG_START,
};
return pwm_config(p, &c);
}
EXPORT_SYMBOL(pwm_start);
int pwm_stop(struct pwm_channel *p)
{
struct pwm_channel_config c = {
.config_mask = PWM_CONFIG_STOP,
};
return pwm_config(p, &c);
}
EXPORT_SYMBOL(pwm_stop);
int pwm_synchronize(struct pwm_channel *p,
struct pwm_channel *to_p)
{
if (p->pwm != to_p->pwm) {
/* TODO: support cross-device synchronization */
return -EINVAL;
}
if (!p->pwm->synchronize)
return -EINVAL;
return p->pwm->synchronize(p, to_p);
}
EXPORT_SYMBOL(pwm_synchronize);
int pwm_unsynchronize(struct pwm_channel *p,
struct pwm_channel *from_p)
{
if (from_p && (p->pwm != from_p->pwm)) {
/* TODO: support cross-device synchronization */
return -EINVAL;
}
if (!p->pwm->unsynchronize)
return -EINVAL;
return p->pwm->unsynchronize(p, from_p);
}
EXPORT_SYMBOL(pwm_unsynchronize);
static void pwm_handler(struct work_struct *w)
{
struct pwm_channel *p = container_of(w, struct pwm_channel,
handler_work);
if (p->handler && p->handler(p, p->handler_data))
pwm_stop(p);
}
static void __pwm_callback(struct pwm_channel *p)
{
queue_work(pwm_handler_workqueue, &p->handler_work);
dev_dbg(p->pwm->dev, "handler %p scheduled with data %p\n",
p->handler, p->handler_data);
}
int pwm_set_handler(struct pwm_channel *p,
pwm_handler_t handler,
void *data)
{
if (p->pwm->set_callback) {
p->handler_data = data;
p->handler = handler;
INIT_WORK(&p->handler_work, pwm_handler);
return p->pwm->set_callback(p, handler ? __pwm_callback : NULL);
}
return -EINVAL;
}
EXPORT_SYMBOL(pwm_set_handler);
static ssize_t pwm_run_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct pwm_channel *p = dev_get_drvdata(dev);
if (sysfs_streq(buf, "1"))
pwm_start(p);
else if (sysfs_streq(buf, "0"))
pwm_stop(p);
return len;
}
static DEVICE_ATTR(run, 0200, NULL, pwm_run_store);
static ssize_t pwm_duty_ns_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct pwm_channel *p = dev_get_drvdata(dev);
return sprintf(buf, "%lu\n", pwm_get_duty_ns(p));
}
static ssize_t pwm_duty_ns_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
unsigned long duty_ns;
struct pwm_channel *p = dev_get_drvdata(dev);
if (1 == sscanf(buf, "%lu", &duty_ns))
pwm_set_duty_ns(p, duty_ns);
return len;
}
static DEVICE_ATTR(duty_ns, 0644, pwm_duty_ns_show, pwm_duty_ns_store);
static ssize_t pwm_period_ns_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct pwm_channel *p = dev_get_drvdata(dev);
return sprintf(buf, "%lu\n", pwm_get_period_ns(p));
}
static ssize_t pwm_period_ns_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
unsigned long period_ns;
struct pwm_channel *p = dev_get_drvdata(dev);
if (1 == sscanf(buf, "%lu", &period_ns))
pwm_set_period_ns(p, period_ns);
return len;
}
static DEVICE_ATTR(period_ns, 0644, pwm_period_ns_show, pwm_period_ns_store);
static ssize_t pwm_polarity_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct pwm_channel *p = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", p->active_high ? 1 : 0);
}
static ssize_t pwm_polarity_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
int polarity;
struct pwm_channel *p = dev_get_drvdata(dev);
if (1 == sscanf(buf, "%d", &polarity))
pwm_set_polarity(p, polarity);
return len;
}
static DEVICE_ATTR(polarity, 0644, pwm_polarity_show, pwm_polarity_store);
static ssize_t pwm_request_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct pwm_channel *p = dev_get_drvdata(dev);
mutex_lock(&device_list_mutex);
__pwm_request_channel(p, REQUEST_SYSFS);
mutex_unlock(&device_list_mutex);
if (p->pid)
return sprintf(buf, "%s %d\n", p->requester, p->pid);
else
return sprintf(buf, "%s\n", p->requester);
}
static ssize_t pwm_request_store(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct pwm_channel *p = dev_get_drvdata(dev);
pwm_free(p);
return len;
}
static DEVICE_ATTR(request, 0644, pwm_request_show, pwm_request_store);
static const struct attribute *pwm_attrs[] =
{
&dev_attr_run.attr,
&dev_attr_polarity.attr,
&dev_attr_duty_ns.attr,
&dev_attr_period_ns.attr,
&dev_attr_request.attr,
NULL,
};
static const struct attribute_group pwm_device_attr_group = {
.attrs = (struct attribute **)pwm_attrs,
};
static int __pwm_create_sysfs(struct pwm_device *pwm)
{
int ret = 0;
struct device *dev;
int wchan;
for (wchan = 0; wchan < pwm->nchan; wchan++) {
dev = device_create(&pwm_class, pwm->dev, MKDEV(0, 0),
pwm->channels + wchan,
"%s:%d", pwm->bus_id, wchan);
if (!dev)
goto err_dev_create;
ret = sysfs_create_group(&dev->kobj, &pwm_device_attr_group);
if (ret)
goto err_dev_create;
}
return ret;
err_dev_create:
for (wchan = 0; wchan < pwm->nchan; wchan++) {
dev = class_find_device(&pwm_class, NULL,
&pwm->channels[wchan],
__match_device);
if (dev) {
put_device(dev);
device_unregister(dev);
}
}
return ret;
}
static struct class_attribute pwm_class_attrs[] = {
__ATTR_NULL,
};
static struct class pwm_class = {
.name = "pwm",
.owner = THIS_MODULE,
.class_attrs = pwm_class_attrs,
};
static int __init pwm_init(void)
{
int ret;
/* TODO: how to deal with devices that register very early? */
pr_err("%s\n", __func__);
ret = class_register(&pwm_class);
if (ret < 0)
return ret;
pwm_handler_workqueue = create_workqueue("pwmd");
return 0;
}
postcore_initcall(pwm_init);