Prev: [PWM PATCH 4/7] Implements PWM-based LED control
Next: [PATCH v2 2/3] powerpc: doc/dts-bindings: document mpc5121 psc uart dts-bindings
From: Bill Gatliff on 9 Feb 2010 15:50

Signed-off-by: Bill Gatliff <bgat(a)billgatliff.com>
---
drivers/misc/Makefile | 1 -
drivers/misc/atmel_pwm.c | 409 --------------------------------
drivers/pwm/atmel-pwm.c | 590 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 590 insertions(+), 410 deletions(-)
delete mode 100644 drivers/misc/atmel_pwm.c
create mode 100644 drivers/pwm/atmel-pwm.c

diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 049ff24..b94666c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -5,7 +5,6 @@
obj-$(CONFIG_IBM_ASM) += ibmasm/
obj-$(CONFIG_HDPU_FEATURES) += hdpuftrs/
obj-$(CONFIG_AD525X_DPOT) += ad525x_dpot.o
-obj-$(CONFIG_ATMEL_PWM) += atmel_pwm.o
obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o
obj-$(CONFIG_ATMEL_TCLIB) += atmel_tclib.o
obj-$(CONFIG_ICS932S401) += ics932s401.o
diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c
deleted file mode 100644
index 6aa5294..0000000
--- a/drivers/misc/atmel_pwm.c
+++ /dev/null
@@ -1,409 +0,0 @@
-#include <linux/module.h>
-#include <linux/clk.h>
-#include <linux/err.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;
-
- /* insist on PWM init, with this signal pinned out */
- if (!pwm || !(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, r->end - r->start + 1);
- 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).
- */
-};
-
-static int __init pwm_init(void)
-{
- return platform_driver_probe(&atmel_pwm_driver, pwm_probe);
-}
-module_init(pwm_init);
-
-static void __exit pwm_exit(void)
-{
- platform_driver_unregister(&atmel_pwm_driver);
-}
-module_exit(pwm_exit);
-
-MODULE_DESCRIPTION("Driver for AT32/AT91 PWM module");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:atmel_pwm");
diff --git a/drivers/pwm/atmel-pwm.c b/drivers/pwm/atmel-pwm.c
new file mode 100644
index 0000000..4f0ef8c
--- /dev/null
+++ b/drivers/pwm/atmel-pwm.c
@@ -0,0 +1,590 @@
+/*
+ * drivers/pwm/atmel-pwm.c
+ *
+ * Copyright (C) 2010 Bill Gatliff <bgat(a)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/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);
+
+ 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(a)billgatliff.com>");
+MODULE_DESCRIPTION("Driver for Atmel PWMC peripheral");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:atmel_pwmc");
--
1.6.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: [PWM PATCH 4/7] Implements PWM-based LED control
Next: [PATCH v2 2/3] powerpc: doc/dts-bindings: document mpc5121 psc uart dts-bindings