Commit 4f6ade91 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'clkdev' of git://git.linaro.org/people/rmk/linux-arm 

Pull clkdev updates from Russell King:
 "This supplements clkdev with a device-managed API, allowing drivers
  cleanup paths to be simplified.  We also optimize clk_find() so that
  it exits as soon as it finds a perfect match, and we provide a way to
  minimise the amount of code platforms need to register clkdev entries.

  Some of the code in arm-soc depends on these changes."

* 'clkdev' of git://git.linaro.org/people/rmk/linux-arm:
  CLKDEV: provide helpers for common clock framework
  ARM: 7392/1: CLKDEV: Optimize clk_find()
  ARM: 7376/1: clkdev: Implement managed clk_get()
parents 31a67102 e9d7f406

Documentation/driver-model/devres.txt

+4 −0
Original line number Diff line number Diff line
@@ -276,3 +276,7 @@ REGULATOR 
  devm_regulator_get()

  devm_regulator_put()

  devm_regulator_bulk_get()



CLOCK

  devm_clk_get()

  devm_clk_put()

drivers/clk/clkdev.c

+132 −10
Original line number Diff line number Diff line
@@ -35,7 +35,12 @@ static DEFINE_MUTEX(clocks_mutex); 
static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)

{

	struct clk_lookup *p, *cl = NULL;

	int match, best = 0;

	int match, best_found = 0, best_possible = 0;



	if (dev_id)

		best_possible += 2;

	if (con_id)

		best_possible += 1;



	list_for_each_entry(p, &clocks, node) {

		match = 0;
@@ -50,10 +55,10 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id) 
			match += 1;

		}



		if (match > best) {

		if (match > best_found) {

			cl = p;

			if (match != 3)

				best = match;

			if (match != best_possible)

				best_found = match;

			else

				break;

		}
@@ -89,6 +94,51 @@ void clk_put(struct clk *clk) 
}

EXPORT_SYMBOL(clk_put);



static void devm_clk_release(struct device *dev, void *res)

{

	clk_put(*(struct clk **)res);

}



struct clk *devm_clk_get(struct device *dev, const char *id)

{

	struct clk **ptr, *clk;



	ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);

	if (!ptr)

		return ERR_PTR(-ENOMEM);



	clk = clk_get(dev, id);

	if (!IS_ERR(clk)) {

		*ptr = clk;

		devres_add(dev, ptr);

	} else {

		devres_free(ptr);

	}



	return clk;

}

EXPORT_SYMBOL(devm_clk_get);



static int devm_clk_match(struct device *dev, void *res, void *data)

{

	struct clk **c = res;

	if (!c || !*c) {

		WARN_ON(!c || !*c);

		return 0;

	}

	return *c == data;

}



void devm_clk_put(struct device *dev, struct clk *clk)

{

	int ret;



	ret = devres_destroy(dev, devm_clk_release, devm_clk_match, clk);



	WARN_ON(ret);

}

EXPORT_SYMBOL(devm_clk_put);



void clkdev_add(struct clk_lookup *cl)

{

	mutex_lock(&clocks_mutex);
@@ -116,8 +166,9 @@ struct clk_lookup_alloc { 
	char	con_id[MAX_CON_ID];

};



struct clk_lookup * __init_refok

clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)

static struct clk_lookup * __init_refok

vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,

	va_list ap)

{

	struct clk_lookup_alloc *cla;
@@ -132,16 +183,25 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) 
	}



	if (dev_fmt) {

		va_list ap;



		va_start(ap, dev_fmt);

		vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);

		cla->cl.dev_id = cla->dev_id;

		va_end(ap);

	}



	return &cla->cl;

}



struct clk_lookup * __init_refok

clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)

{

	struct clk_lookup *cl;

	va_list ap;



	va_start(ap, dev_fmt);

	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);

	va_end(ap);



	return cl;

}

EXPORT_SYMBOL(clkdev_alloc);



int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
@@ -173,3 +233,65 @@ void clkdev_drop(struct clk_lookup *cl) 
	kfree(cl);

}

EXPORT_SYMBOL(clkdev_drop);



/**

 * clk_register_clkdev - register one clock lookup for a struct clk

 * @clk: struct clk to associate with all clk_lookups

 * @con_id: connection ID string on device

 * @dev_id: format string describing device name

 *

 * con_id or dev_id may be NULL as a wildcard, just as in the rest of

 * clkdev.

 *

 * To make things easier for mass registration, we detect error clks

 * from a previous clk_register() call, and return the error code for

 * those.  This is to permit this function to be called immediately

 * after clk_register().

 */

int clk_register_clkdev(struct clk *clk, const char *con_id,

	const char *dev_fmt, ...)

{

	struct clk_lookup *cl;

	va_list ap;



	if (IS_ERR(clk))

		return PTR_ERR(clk);



	va_start(ap, dev_fmt);

	cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);

	va_end(ap);



	if (!cl)

		return -ENOMEM;



	clkdev_add(cl);



	return 0;

}



/**

 * clk_register_clkdevs - register a set of clk_lookup for a struct clk

 * @clk: struct clk to associate with all clk_lookups

 * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized

 * @num: number of clk_lookup structures to register

 *

 * To make things easier for mass registration, we detect error clks

 * from a previous clk_register() call, and return the error code for

 * those.  This is to permit this function to be called immediately

 * after clk_register().

 */

int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)

{

	unsigned i;



	if (IS_ERR(clk))

		return PTR_ERR(clk);



	for (i = 0; i < num; i++, cl++) {

		cl->clk = clk;

		clkdev_add(cl);

	}



	return 0;

}

EXPORT_SYMBOL(clk_register_clkdevs);

include/linux/clk.h

+32 −0
Original line number Diff line number Diff line
@@ -100,6 +100,26 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); 
 */

struct clk *clk_get(struct device *dev, const char *id);



/**

 * devm_clk_get - lookup and obtain a managed reference to a clock producer.

 * @dev: device for clock "consumer"

 * @id: clock comsumer ID

 *

 * Returns a struct clk corresponding to the clock producer, or

 * valid IS_ERR() condition containing errno.  The implementation

 * uses @dev and @id to determine the clock consumer, and thereby

 * the clock producer.  (IOW, @id may be identical strings, but

 * clk_get may return different clock producers depending on @dev.)

 *

 * Drivers must assume that the clock source is not enabled.

 *

 * devm_clk_get should not be called from within interrupt context.

 *

 * The clock will automatically be freed when the device is unbound

 * from the bus.

 */

struct clk *devm_clk_get(struct device *dev, const char *id);



/**

 * clk_prepare - prepare a clock source

 * @clk: clock source
@@ -206,6 +226,18 @@ unsigned long clk_get_rate(struct clk *clk); 
 */

void clk_put(struct clk *clk);



/**

 * devm_clk_put	- "free" a managed clock source

 * @dev: device used to acuqire the clock

 * @clk: clock source acquired with devm_clk_get()

 *

 * Note: drivers must ensure that all clk_enable calls made on this

 * clock source are balanced by clk_disable calls prior to calling

 * this function.

 *

 * clk_put should not be called from within interrupt context.

 */

void devm_clk_put(struct device *dev, struct clk *clk);



/*

 * The remaining APIs are optional for machine class support.

include/linux/clkdev.h

+3 −0
Original line number Diff line number Diff line
@@ -40,4 +40,7 @@ void clkdev_drop(struct clk_lookup *cl); 
void clkdev_add_table(struct clk_lookup *, size_t);

int clk_add_alias(const char *, const char *, char *, struct device *);



int clk_register_clkdev(struct clk *, const char *, const char *, ...);

int clk_register_clkdevs(struct clk *, struct clk_lookup *, size_t);



#endif

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