+++ /dev/null
-/*
- * 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");
projects / openwrt / staging / wigyori.git / blobdiff