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yaml
---
r: 374666
b: refs/heads/master
c: de61608
h: refs/heads/master
v: v3
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Lars-Peter Clausen authored and Vinod Koul committed May 2, 2013
1 parent 22aac6c commit 8a372f2
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Showing 3 changed files with 23 additions and 61 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: f22eb1402244885126c4263eb36b857e4182dd6f
refs/heads/master: de61608acf89779c8831aaa1428b6975d49d98c0
76 changes: 20 additions & 56 deletions trunk/drivers/dma/of-dma.c
Original file line number Diff line number Diff line change
Expand Up @@ -13,61 +13,38 @@
#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/rculist.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_dma.h>

static LIST_HEAD(of_dma_list);
static DEFINE_SPINLOCK(of_dma_lock);
static DEFINE_MUTEX(of_dma_lock);

/**
* of_dma_get_controller - Get a DMA controller in DT DMA helpers list
* of_dma_find_controller - Get a DMA controller in DT DMA helpers list
* @dma_spec: pointer to DMA specifier as found in the device tree
*
* Finds a DMA controller with matching device node and number for dma cells
* in a list of registered DMA controllers. If a match is found the use_count
* variable is increased and a valid pointer to the DMA data stored is retuned.
* A NULL pointer is returned if no match is found.
* in a list of registered DMA controllers. If a match is found a valid pointer
* to the DMA data stored is retuned. A NULL pointer is returned if no match is
* found.
*/
static struct of_dma *of_dma_get_controller(struct of_phandle_args *dma_spec)
static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec)
{
struct of_dma *ofdma;

spin_lock(&of_dma_lock);

list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers)
if ((ofdma->of_node == dma_spec->np) &&
(ofdma->of_dma_nbcells == dma_spec->args_count)) {
ofdma->use_count++;
spin_unlock(&of_dma_lock);
(ofdma->of_dma_nbcells == dma_spec->args_count))
return ofdma;
}

spin_unlock(&of_dma_lock);

pr_debug("%s: can't find DMA controller %s\n", __func__,
dma_spec->np->full_name);

return NULL;
}

/**
* of_dma_put_controller - Decrement use count for a registered DMA controller
* @of_dma: pointer to DMA controller data
*
* Decrements the use_count variable in the DMA data structure. This function
* should be called only when a valid pointer is returned from
* of_dma_get_controller() and no further accesses to data referenced by that
* pointer are needed.
*/
static void of_dma_put_controller(struct of_dma *ofdma)
{
spin_lock(&of_dma_lock);
ofdma->use_count--;
spin_unlock(&of_dma_lock);
}

/**
* of_dma_controller_register - Register a DMA controller to DT DMA helpers
* @np: device node of DMA controller
Expand Down Expand Up @@ -114,12 +91,11 @@ int of_dma_controller_register(struct device_node *np,
ofdma->of_dma_nbcells = nbcells;
ofdma->of_dma_xlate = of_dma_xlate;
ofdma->of_dma_data = data;
ofdma->use_count = 0;

/* Now queue of_dma controller structure in list */
spin_lock(&of_dma_lock);
mutex_lock(&of_dma_lock);
list_add_tail(&ofdma->of_dma_controllers, &of_dma_list);
spin_unlock(&of_dma_lock);
mutex_unlock(&of_dma_lock);

return 0;
}
Expand All @@ -131,32 +107,20 @@ EXPORT_SYMBOL_GPL(of_dma_controller_register);
*
* Memory allocated by of_dma_controller_register() is freed here.
*/
int of_dma_controller_free(struct device_node *np)
void of_dma_controller_free(struct device_node *np)
{
struct of_dma *ofdma;

spin_lock(&of_dma_lock);

if (list_empty(&of_dma_list)) {
spin_unlock(&of_dma_lock);
return -ENODEV;
}
mutex_lock(&of_dma_lock);

list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers)
if (ofdma->of_node == np) {
if (ofdma->use_count) {
spin_unlock(&of_dma_lock);
return -EBUSY;
}

list_del(&ofdma->of_dma_controllers);
spin_unlock(&of_dma_lock);
kfree(ofdma);
return 0;
break;
}

spin_unlock(&of_dma_lock);
return -ENODEV;
mutex_unlock(&of_dma_lock);
}
EXPORT_SYMBOL_GPL(of_dma_controller_free);

Expand Down Expand Up @@ -219,15 +183,15 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
if (of_dma_match_channel(np, name, i, &dma_spec))
continue;

ofdma = of_dma_get_controller(&dma_spec);
mutex_lock(&of_dma_lock);
ofdma = of_dma_find_controller(&dma_spec);

if (ofdma) {
if (ofdma)
chan = ofdma->of_dma_xlate(&dma_spec, ofdma);

of_dma_put_controller(ofdma);
} else {
else
chan = NULL;
}

mutex_unlock(&of_dma_lock);

of_node_put(dma_spec.np);

Expand Down
6 changes: 2 additions & 4 deletions trunk/include/linux/of_dma.h
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,6 @@ struct of_dma {
struct dma_chan *(*of_dma_xlate)
(struct of_phandle_args *, struct of_dma *);
void *of_dma_data;
int use_count;
};

struct of_dma_filter_info {
Expand All @@ -38,7 +37,7 @@ extern int of_dma_controller_register(struct device_node *np,
struct dma_chan *(*of_dma_xlate)
(struct of_phandle_args *, struct of_dma *),
void *data);
extern int of_dma_controller_free(struct device_node *np);
extern void of_dma_controller_free(struct device_node *np);
extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
const char *name);
extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
Expand All @@ -52,9 +51,8 @@ static inline int of_dma_controller_register(struct device_node *np,
return -ENODEV;
}

static inline int of_dma_controller_free(struct device_node *np)
static inline void of_dma_controller_free(struct device_node *np)
{
return -ENODEV;
}

static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
Expand Down

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