[RFC PATCH] DMA: PL330: Update PL330 DMAC to support runtime PM
Chanwoo Choi
cw00.choi at samsung.com
Wed Jul 27 02:14:27 EDT 2011
This patch update runtime PM for PL330 DMAC to reduce power consumption.
Signed-off-by: Chanwoo Choi <cw00.choi at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
The following patch support runtime PM for PL330 DMAC, but the clock
of PL330 is always on. If the clock of PL330 is always on, additional power
(10mA) is consumed.
"[PATCH 01/15] DMA: PL330: Add support runtime PM for PL330 DMAC"
http://permalink.gmane.org/gmane.linux.kernel.samsung-soc/5931
arch/arm/plat-samsung/dma-ops.c | 21 +++++++++++
drivers/dma/pl330.c | 76 +++++++++++++--------------------------
include/linux/amba/pl330.h | 54 +++++++++++++++++++++++++++
3 files changed, 100 insertions(+), 51 deletions(-)
diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma-ops.c
index 9053433..b726e4a 100644
--- a/arch/arm/plat-samsung/dma-ops.c
+++ b/arch/arm/plat-samsung/dma-ops.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/amba/pl330.h>
+#include <linux/pm_runtime.h>
#include <mach/dma.h>
@@ -33,12 +34,23 @@ static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
struct dma_chan *chan;
dma_cap_mask_t mask;
struct dma_slave_config slave_config;
+#ifdef CONFIG_PM_RUNTIME
+ struct dma_pl330_chan *pch;
+ struct dma_pl330_dmac *pdmac;
+#endif
dma_cap_zero(mask);
dma_cap_set(info->cap, mask);
chan = dma_request_channel(mask, pl330_filter, (void *)dma_ch);
+#ifdef CONFIG_PM_RUNTIME
+ pch = container_of(chan, struct dma_pl330_chan, chan);
+ pdmac = pch->dmac;
+
+ pm_runtime_get_sync(pdmac->pif.dev);
+#endif
+
if (info->direction == DMA_FROM_DEVICE) {
memset(&slave_config, 0, sizeof(struct dma_slave_config));
slave_config.direction = info->direction;
@@ -59,8 +71,17 @@ static unsigned samsung_dmadev_request(enum dma_ch dma_ch,
static int samsung_dmadev_release(unsigned ch,
struct s3c2410_dma_client *client)
{
+#ifdef CONFIG_PM_RUNTIME
+ struct dma_pl330_chan *pch =
+ container_of((struct dma_chan *)ch, struct dma_pl330_chan, chan);
+ struct dma_pl330_dmac *pdmac = pdmac = pch->dmac;;
+#endif
+
dma_release_channel((struct dma_chan *)ch);
+#ifdef CONFIG_PM_RUNTIME
+ pm_runtime_put(pdmac->pif.dev);
+#endif
return 0;
}
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 121c75a..14d0ba6 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -42,57 +42,6 @@ enum desc_status {
DONE,
};
-struct dma_pl330_chan {
- /* Schedule desc completion */
- struct tasklet_struct task;
-
- /* DMA-Engine Channel */
- struct dma_chan chan;
-
- /* Last completed cookie */
- dma_cookie_t completed;
-
- /* List of to be xfered descriptors */
- struct list_head work_list;
-
- /* Pointer to the DMAC that manages this channel,
- * NULL if the channel is available to be acquired.
- * As the parent, this DMAC also provides descriptors
- * to the channel.
- */
- struct dma_pl330_dmac *dmac;
-
- /* To protect channel manipulation */
- spinlock_t lock;
-
- /* Token of a hardware channel thread of PL330 DMAC
- * NULL if the channel is available to be acquired.
- */
- void *pl330_chid;
-
- /* taks for cyclic capability */
- struct tasklet_struct *cyclic_task;
-
- bool cyclic;
-};
-
-struct dma_pl330_dmac {
- struct pl330_info pif;
-
- /* DMA-Engine Device */
- struct dma_device ddma;
-
- /* Pool of descriptors available for the DMAC's channels */
- struct list_head desc_pool;
- /* To protect desc_pool manipulation */
- spinlock_t pool_lock;
-
- /* Peripheral channels connected to this DMAC */
- struct dma_pl330_chan peripherals[0]; /* keep at end */
-
- struct clk *clk;
-};
-
struct dma_pl330_desc {
/* To attach to a queue as child */
struct list_head node;
@@ -935,6 +884,18 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
pi->pcfg.data_bus_width / 8, pi->pcfg.num_chan,
pi->pcfg.num_peri, pi->pcfg.num_events);
+#ifdef CONFIG_PM_RUNTIME
+ /* disable the power domain */
+ ret = pm_runtime_put(&adev->dev);
+ if (ret < 0) {
+ dev_err(&adev->dev, "failed to put runtime pm\n");
+ ret = -ENODEV;
+ goto probe_err4;
+ }
+#else
+ /* disable dma clk */
+ clk_disable(pdmac->clk);
+#endif
return 0;
probe_err4:
@@ -943,6 +904,13 @@ probe_err3:
free_irq(irq, pi);
probe_err2:
iounmap(pi->base);
+
+#ifdef CONFIG_PM_RUNTIME
+ pm_runtime_disable(&adev->dev);
+ pm_runtime_put(&adev->dev);
+#else
+ clk_disable(pdmac->clk);
+#endif
probe_err1:
release_mem_region(res->start, resource_size(res));
kfree(pdmac);
@@ -961,6 +929,12 @@ static int __devexit pl330_remove(struct amba_device *adev)
if (!pdmac)
return 0;
+#ifdef CONFIG_PM_RUNTIME
+ pm_runtime_get_sync(&adev->dev);
+#else
+ clk_enable(pdmac->clk);
+#endif
+
amba_set_drvdata(adev, NULL);
/* Idle the DMAC */
diff --git a/include/linux/amba/pl330.h b/include/linux/amba/pl330.h
index 17b0ada..d9a63fd 100644
--- a/include/linux/amba/pl330.h
+++ b/include/linux/amba/pl330.h
@@ -12,6 +12,9 @@
#ifndef __AMBA_PL330_H_
#define __AMBA_PL330_H_
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+
#include <asm/hardware/pl330.h>
struct dma_pl330_peri {
@@ -42,4 +45,55 @@ struct dma_pl330_platdata {
unsigned mcbuf_sz;
};
+struct dma_pl330_chan {
+ /* Schedule desc completion */
+ struct tasklet_struct task;
+
+ /* DMA-Engine Channel */
+ struct dma_chan chan;
+
+ /* Last completed cookie */
+ dma_cookie_t completed;
+
+ /* List of to be xfered descriptors */
+ struct list_head work_list;
+
+ /* Pointer to the DMAC that manages this channel,
+ * NULL if the channel is available to be acquired.
+ * As the parent, this DMAC also provides descriptors
+ * to the channel.
+ */
+ struct dma_pl330_dmac *dmac;
+
+ /* To protect channel manipulation */
+ spinlock_t lock;
+
+ /* Token of a hardware channel thread of PL330 DMAC
+ * NULL if the channel is available to be acquired.
+ */
+ void *pl330_chid;
+
+ /* taks for cyclic capability */
+ struct tasklet_struct *cyclic_task;
+
+ bool cyclic;
+};
+
+struct dma_pl330_dmac {
+ struct pl330_info pif;
+
+ /* DMA-Engine Device */
+ struct dma_device ddma;
+
+ /* Pool of descriptors available for the DMAC's channels */
+ struct list_head desc_pool;
+ /* To protect desc_pool manipulation */
+ spinlock_t pool_lock;
+
+ /* Peripheral channels connected to this DMAC */
+ struct dma_pl330_chan peripherals[0]; /* keep at end */
+
+ struct clk *clk;
+};
+
#endif /* __AMBA_PL330_H_ */
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