WSL2-Linux-Kernel/drivers/misc/atmel_pwm.c

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#include <linux/module.h>
#include <linux/clk.h>
#include <linux/err.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 11:04:11 +03:00
#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;
/* 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");