+++ /dev/null
-#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");
+++ /dev/null
-#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 */
projects / karo-tx-linux.git / commitdiff