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Commit f2a70e1f authored by Alexandre Belloni's avatar Alexandre Belloni Committed by Nicolas Ferre
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misc: atmel_pwm: remove obsolete driver 

The misc/atmel_pwm is not used by any mainlined boards and has been replaced by
the pwm-driver using the generic PWM framework.
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
parent 3088883b
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drivers/misc/Kconfig
View file @ f2a70e1f
......@@ -51,16 +51,6 @@ config AD525X_DPOT_SPI
To compile this driver as a module, choose M here: the
module will be called ad525x_dpot-spi.
config ATMEL_PWM
tristate "Atmel AT32/AT91 PWM support"
depends on HAVE_CLK
depends on AVR32 || ARCH_AT91SAM9263 || ARCH_AT91SAM9RL || ARCH_AT91SAM9G45
help
This option enables device driver support for the PWM channels
on certain Atmel processors. Pulse Width Modulation is used for
purposes including software controlled power-efficient backlights
on LCD displays, motor control, and waveform generation.
config ATMEL_TCLIB
bool "Atmel AT32/AT91 Timer/Counter Library"
depends on (AVR32 || ARCH_AT91)
......
drivers/misc/Makefile
View file @ f2a70e1f
......@@ -7,7 +7,6 @@ obj-$(CONFIG_AD525X_DPOT) += ad525x_dpot.o
obj-$(CONFIG_AD525X_DPOT_I2C) += ad525x_dpot-i2c.o
obj-$(CONFIG_AD525X_DPOT_SPI) += ad525x_dpot-spi.o
obj-$(CONFIG_INTEL_MID_PTI) += pti.o
obj-$(CONFIG_ATMEL_PWM) += atmel_pwm.o
obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o
obj-$(CONFIG_ATMEL_TCLIB) += atmel_tclib.o
obj-$(CONFIG_BMP085) += bmp085.o
......
drivers/misc/atmel_pwm.c deleted 100644 → 0
View file @ 3088883b
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/atmel_pwm.h>
/*
* This is a simple driver for the PWM controller found in various newer
* Atmel SOCs, including the AVR32 series and the AT91sam9263.
*
* Chips with current Linux ports have only 4 PWM channels, out of max 32.
* AT32UC3A and AT32UC3B chips have 7 channels (but currently no Linux).
* Docs are inconsistent about the width of the channel counter registers;
* it's at least 16 bits, but several places say 20 bits.
*/
#define PWM_NCHAN 4 /* max 32 */
struct pwm {
spinlock_t lock;
struct platform_device *pdev;
u32 mask;
int irq;
void __iomem *base;
struct clk *clk;
struct pwm_channel *channel[PWM_NCHAN];
void (*handler[PWM_NCHAN])(struct pwm_channel *);
};
/* global PWM controller registers */
#define PWM_MR 0x00
#define PWM_ENA 0x04
#define PWM_DIS 0x08
#define PWM_SR 0x0c
#define PWM_IER 0x10
#define PWM_IDR 0x14
#define PWM_IMR 0x18
#define PWM_ISR 0x1c
static inline void pwm_writel(const struct pwm *p, unsigned offset, u32 val)
{
__raw_writel(val, p->base + offset);
}
static inline u32 pwm_readl(const struct pwm *p, unsigned offset)
{
return __raw_readl(p->base + offset);
}
static inline void __iomem *pwmc_regs(const struct pwm *p, int index)
{
return p->base + 0x200 + index * 0x20;
}
static struct pwm *pwm;
static void pwm_dumpregs(struct pwm_channel *ch, char *tag)
{
struct device *dev = &pwm->pdev->dev;
dev_dbg(dev, "%s: mr %08x, sr %08x, imr %08x\n",
tag,
pwm_readl(pwm, PWM_MR),
pwm_readl(pwm, PWM_SR),
pwm_readl(pwm, PWM_IMR));
dev_dbg(dev,
"pwm ch%d - mr %08x, dty %u, prd %u, cnt %u\n",
ch->index,
pwm_channel_readl(ch, PWM_CMR),
pwm_channel_readl(ch, PWM_CDTY),
pwm_channel_readl(ch, PWM_CPRD),
pwm_channel_readl(ch, PWM_CCNT));
}
/**
* pwm_channel_alloc - allocate an unused PWM channel
* @index: identifies the channel
* @ch: structure to be initialized
*
* Drivers allocate PWM channels according to the board's wiring, and
* matching board-specific setup code. Returns zero or negative errno.
*/
int pwm_channel_alloc(int index, struct pwm_channel *ch)
{
unsigned long flags;
int status = 0;
if (!pwm)
return -EPROBE_DEFER;
if (!(pwm->mask & 1 << index))
return -ENODEV;
if (index < 0 || index >= PWM_NCHAN || !ch)
return -EINVAL;
memset(ch, 0, sizeof *ch);
spin_lock_irqsave(&pwm->lock, flags);
if (pwm->channel[index])
status = -EBUSY;
else {
clk_enable(pwm->clk);
ch->regs = pwmc_regs(pwm, index);
ch->index = index;
/* REVISIT: ap7000 seems to go 2x as fast as we expect!! */
ch->mck = clk_get_rate(pwm->clk);
pwm->channel[index] = ch;
pwm->handler[index] = NULL;
/* channel and irq are always disabled when we return */
pwm_writel(pwm, PWM_DIS, 1 << index);
pwm_writel(pwm, PWM_IDR, 1 << index);
}
spin_unlock_irqrestore(&pwm->lock, flags);
return status;
}
EXPORT_SYMBOL(pwm_channel_alloc);
static int pwmcheck(struct pwm_channel *ch)
{
int index;
if (!pwm)
return -ENODEV;
if (!ch)
return -EINVAL;
index = ch->index;
if (index < 0 || index >= PWM_NCHAN || pwm->channel[index] != ch)
return -EINVAL;
return index;
}
/**
* pwm_channel_free - release a previously allocated channel
* @ch: the channel being released
*
* The channel is completely shut down (counter and IRQ disabled),
* and made available for re-use. Returns zero, or negative errno.
*/
int pwm_channel_free(struct pwm_channel *ch)
{
unsigned long flags;
int t;
spin_lock_irqsave(&pwm->lock, flags);
t = pwmcheck(ch);
if (t >= 0) {
pwm->channel[t] = NULL;
pwm->handler[t] = NULL;
/* channel and irq are always disabled when we return */
pwm_writel(pwm, PWM_DIS, 1 << t);
pwm_writel(pwm, PWM_IDR, 1 << t);
clk_disable(pwm->clk);
t = 0;
}
spin_unlock_irqrestore(&pwm->lock, flags);
return t;
}
EXPORT_SYMBOL(pwm_channel_free);
int __pwm_channel_onoff(struct pwm_channel *ch, int enabled)
{
unsigned long flags;
int t;
/* OMITTED FUNCTIONALITY: starting several channels in synch */
spin_lock_irqsave(&pwm->lock, flags);
t = pwmcheck(ch);
if (t >= 0) {
pwm_writel(pwm, enabled ? PWM_ENA : PWM_DIS, 1 << t);
t = 0;
pwm_dumpregs(ch, enabled ? "enable" : "disable");
}
spin_unlock_irqrestore(&pwm->lock, flags);
return t;
}
EXPORT_SYMBOL(__pwm_channel_onoff);
/**
* pwm_clk_alloc - allocate and configure CLKA or CLKB
* @prescale: from 0..10, the power of two used to divide MCK
* @div: from 1..255, the linear divisor to use
*
* Returns PWM_CPR_CLKA, PWM_CPR_CLKB, or negative errno. The allocated
* clock will run with a period of (2^prescale * div) / MCK, or twice as
* long if center aligned PWM output is used. The clock must later be
* deconfigured using pwm_clk_free().
*/
int pwm_clk_alloc(unsigned prescale, unsigned div)
{
unsigned long flags;
u32 mr;
u32 val = (prescale << 8) | div;
int ret = -EBUSY;
if (prescale >= 10 || div == 0 || div > 255)
return -EINVAL;
spin_lock_irqsave(&pwm->lock, flags);
mr = pwm_readl(pwm, PWM_MR);
if ((mr & 0xffff) == 0) {
mr |= val;
ret = PWM_CPR_CLKA;
} else if ((mr & (0xffff << 16)) == 0) {
mr |= val << 16;
ret = PWM_CPR_CLKB;
}
if (ret > 0)
pwm_writel(pwm, PWM_MR, mr);
spin_unlock_irqrestore(&pwm->lock, flags);
return ret;
}
EXPORT_SYMBOL(pwm_clk_alloc);
/**
* pwm_clk_free - deconfigure and release CLKA or CLKB
*
* Reverses the effect of pwm_clk_alloc().
*/
void pwm_clk_free(unsigned clk)
{
unsigned long flags;
u32 mr;
spin_lock_irqsave(&pwm->lock, flags);
mr = pwm_readl(pwm, PWM_MR);
if (clk == PWM_CPR_CLKA)
pwm_writel(pwm, PWM_MR, mr & ~(0xffff << 0));
if (clk == PWM_CPR_CLKB)
pwm_writel(pwm, PWM_MR, mr & ~(0xffff << 16));
spin_unlock_irqrestore(&pwm->lock, flags);
}
EXPORT_SYMBOL(pwm_clk_free);
/**
* pwm_channel_handler - manage channel's IRQ handler
* @ch: the channel
* @handler: the handler to use, possibly NULL
*
* If the handler is non-null, the handler will be called after every
* period of this PWM channel. If the handler is null, this channel
* won't generate an IRQ.
*/
int pwm_channel_handler(struct pwm_channel *ch,
void (*handler)(struct pwm_channel *ch))
{
unsigned long flags;
int t;
spin_lock_irqsave(&pwm->lock, flags);
t = pwmcheck(ch);
if (t >= 0) {
pwm->handler[t] = handler;
pwm_writel(pwm, handler ? PWM_IER : PWM_IDR, 1 << t);
t = 0;
}
spin_unlock_irqrestore(&pwm->lock, flags);
return t;
}
EXPORT_SYMBOL(pwm_channel_handler);
static irqreturn_t pwm_irq(int id, void *_pwm)
{
struct pwm *p = _pwm;
irqreturn_t handled = IRQ_NONE;
u32 irqstat;
int index;
spin_lock(&p->lock);
/* ack irqs, then handle them */
irqstat = pwm_readl(pwm, PWM_ISR);
while (irqstat) {
struct pwm_channel *ch;
void (*handler)(struct pwm_channel *ch);
index = ffs(irqstat) - 1;
irqstat &= ~(1 << index);
ch = pwm->channel[index];
handler = pwm->handler[index];
if (handler && ch) {
spin_unlock(&p->lock);
handler(ch);
spin_lock(&p->lock);
handled = IRQ_HANDLED;
}
}
spin_unlock(&p->lock);
return handled;
}
static int __init pwm_probe(struct platform_device *pdev)
{
struct resource *r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
int irq = platform_get_irq(pdev, 0);
u32 *mp = pdev->dev.platform_data;
struct pwm *p;
int status = -EIO;
if (pwm)
return -EBUSY;
if (!r || irq < 0 || !mp || !*mp)
return -ENODEV;
if (*mp & ~((1<<PWM_NCHAN)-1)) {
dev_warn(&pdev->dev, "mask 0x%x ... more than %d channels\n",
*mp, PWM_NCHAN);
return -EINVAL;
}
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
spin_lock_init(&p->lock);
p->pdev = pdev;
p->mask = *mp;
p->irq = irq;
p->base = ioremap(r->start, resource_size(r));
if (!p->base)
goto fail;
p->clk = clk_get(&pdev->dev, "pwm_clk");
if (IS_ERR(p->clk)) {
status = PTR_ERR(p->clk);
p->clk = NULL;
goto fail;
}
status = request_irq(irq, pwm_irq, 0, pdev->name, p);
if (status < 0)
goto fail;
pwm = p;
platform_set_drvdata(pdev, p);
return 0;
fail:
if (p->clk)
clk_put(p->clk);
if (p->base)
iounmap(p->base);
kfree(p);
return status;
}
static int __exit pwm_remove(struct platform_device *pdev)
{
struct pwm *p = platform_get_drvdata(pdev);
if (p != pwm)
return -EINVAL;
clk_enable(pwm->clk);
pwm_writel(pwm, PWM_DIS, (1 << PWM_NCHAN) - 1);
pwm_writel(pwm, PWM_IDR, (1 << PWM_NCHAN) - 1);
clk_disable(pwm->clk);
pwm = NULL;
free_irq(p->irq, p);
clk_put(p->clk);
iounmap(p->base);
kfree(p);
return 0;
}
static struct platform_driver atmel_pwm_driver = {
.driver = {
.name = "atmel_pwm",
.owner = THIS_MODULE,
},
.remove = __exit_p(pwm_remove),
/* NOTE: PWM can keep running in AVR32 "idle" and "frozen" states;
* and all AT91sam9263 states, albeit at reduced clock rate if
* MCK becomes the slow clock (i.e. what Linux labels STR).
*/
};
module_platform_driver_probe(atmel_pwm_driver, pwm_probe);
MODULE_DESCRIPTION("Driver for AT32/AT91 PWM module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:atmel_pwm");
include/linux/atmel_pwm.h deleted 100644 → 0
View file @ 3088883b
#ifndef __LINUX_ATMEL_PWM_H
#define __LINUX_ATMEL_PWM_H
/**
* struct pwm_channel - driver handle to a PWM channel
* @regs: base of this channel's registers
* @index: number of this channel (0..31)
* @mck: base clock rate, which can be prescaled and maybe subdivided
*
* Drivers initialize a pwm_channel structure using pwm_channel_alloc().
* Then they configure its clock rate (derived from MCK), alignment,
* polarity, and duty cycle by writing directly to the channel registers,
* before enabling the channel by calling pwm_channel_enable().
*
* After emitting a PWM signal for the desired length of time, drivers
* may then pwm_channel_disable() or pwm_channel_free(). Both of these
* disable the channel, but when it's freed the IRQ is deconfigured and
* the channel must later be re-allocated and reconfigured.
*
* Note that if the period or duty cycle need to be changed while the
* PWM channel is operating, drivers must use the PWM_CUPD double buffer
* mechanism, either polling until they change or getting implicitly
* notified through a once-per-period interrupt handler.
*/
struct pwm_channel {
void __iomem *regs;
unsigned index;
unsigned long mck;
};
extern int pwm_channel_alloc(int index, struct pwm_channel *ch);
extern int pwm_channel_free(struct pwm_channel *ch);
extern int pwm_clk_alloc(unsigned prescale, unsigned div);
extern void pwm_clk_free(unsigned clk);
extern int __pwm_channel_onoff(struct pwm_channel *ch, int enabled);
#define pwm_channel_enable(ch) __pwm_channel_onoff((ch), 1)
#define pwm_channel_disable(ch) __pwm_channel_onoff((ch), 0)
/* periodic interrupts, mostly for CUPD changes to period or cycle */
extern int pwm_channel_handler(struct pwm_channel *ch,
void (*handler)(struct pwm_channel *ch));
/* per-channel registers (banked at pwm_channel->regs) */
#define PWM_CMR 0x00 /* mode register */
#define PWM_CPR_CPD (1 << 10) /* set: CUPD modifies period */
#define PWM_CPR_CPOL (1 << 9) /* set: idle high */
#define PWM_CPR_CALG (1 << 8) /* set: center align */
#define PWM_CPR_CPRE (0xf << 0) /* mask: rate is mck/(2^pre) */
#define PWM_CPR_CLKA (0xb << 0) /* rate CLKA */
#define PWM_CPR_CLKB (0xc << 0) /* rate CLKB */
#define PWM_CDTY 0x04 /* duty cycle (max of CPRD) */
#define PWM_CPRD 0x08 /* period (count up from zero) */
#define PWM_CCNT 0x0c /* counter (20 bits?) */
#define PWM_CUPD 0x10 /* update CPRD (or CDTY) next period */
static inline void
pwm_channel_writel(struct pwm_channel *pwmc, unsigned offset, u32 val)
{
__raw_writel(val, pwmc->regs + offset);
}
static inline u32 pwm_channel_readl(struct pwm_channel *pwmc, unsigned offset)
{
return __raw_readl(pwmc->regs + offset);
}
#endif /* __LINUX_ATMEL_PWM_H */
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