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"); |