diff options
Diffstat (limited to 'drivers/misc/atmel_pwm.c')
| -rw-r--r-- | drivers/misc/atmel_pwm.c | 402 | 
1 files changed, 0 insertions, 402 deletions
diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c deleted file mode 100644 index a6dc56e1bc58..000000000000 --- a/drivers/misc/atmel_pwm.c +++ /dev/null @@ -1,402 +0,0 @@ -#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");  |