[PATCH v2] dmaengine: sirf: add PM entries for sleep and runtime
Barry Song
21cnbao at gmail.com
Tue Jul 30 05:44:34 EDT 2013
this patch adds PM ops entries in sirf-dma drivers, so that this
driver can support suspend/resume, hibernation and runtime PM.
while suspending, sirf-dma will lose all registers, so we save
them at suspend and restore in resume for active channels.
Signed-off-by: Barry Song <Baohua.Song at csr.com>
Signed-off-by: Rongjun Ying <Rongjun.Ying at csr.com>
---
-v2: add comments for PM state machine;
don't always put dma to suspended after resuming from sleep as it
depends on the runtime pm status;
drivers/dma/sirf-dma.c | 132 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 129 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
index 716b23e..ff3cdd2 100644
--- a/drivers/dma/sirf-dma.c
+++ b/drivers/dma/sirf-dma.c
@@ -9,6 +9,7 @@
#include <linux/module.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
+#include <linux/pm_runtime.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/slab.h>
@@ -73,6 +74,11 @@ struct sirfsoc_dma_chan {
int mode;
};
+struct sirfsoc_dma_regs {
+ u32 ctrl[SIRFSOC_DMA_CHANNELS];
+ u32 interrupt_en;
+};
+
struct sirfsoc_dma {
struct dma_device dma;
struct tasklet_struct tasklet;
@@ -81,10 +87,13 @@ struct sirfsoc_dma {
int irq;
struct clk *clk;
bool is_marco;
+ struct sirfsoc_dma_regs regs_save;
};
#define DRV_NAME "sirfsoc_dma"
+static int sirfsoc_dma_runtime_suspend(struct device *dev);
+
/* Convert struct dma_chan to struct sirfsoc_dma_chan */
static inline
struct sirfsoc_dma_chan *dma_chan_to_sirfsoc_dma_chan(struct dma_chan *c)
@@ -393,6 +402,8 @@ static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan)
LIST_HEAD(descs);
int i;
+ pm_runtime_get_sync(sdma->dma.dev);
+
/* Alloc descriptors for this channel */
for (i = 0; i < SIRFSOC_DMA_DESCRIPTORS; i++) {
sdesc = kzalloc(sizeof(*sdesc), GFP_KERNEL);
@@ -425,6 +436,7 @@ static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan)
static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan)
{
struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+ struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
struct sirfsoc_dma_desc *sdesc, *tmp;
unsigned long flags;
LIST_HEAD(descs);
@@ -445,6 +457,8 @@ static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan)
/* Free descriptors */
list_for_each_entry_safe(sdesc, tmp, &descs, node)
kfree(sdesc);
+
+ pm_runtime_put(sdma->dma.dev);
}
/* Send pending descriptor to hardware */
@@ -723,14 +737,14 @@ static int sirfsoc_dma_probe(struct platform_device *op)
tasklet_init(&sdma->tasklet, sirfsoc_dma_tasklet, (unsigned long)sdma);
- clk_prepare_enable(sdma->clk);
-
/* Register DMA engine */
dev_set_drvdata(dev, sdma);
+
ret = dma_async_device_register(dma);
if (ret)
goto free_irq;
+ pm_runtime_enable(&op->dev);
dev_info(dev, "initialized SIRFSOC DMAC driver\n");
return 0;
@@ -747,13 +761,124 @@ static int sirfsoc_dma_remove(struct platform_device *op)
struct device *dev = &op->dev;
struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
- clk_disable_unprepare(sdma->clk);
dma_async_device_unregister(&sdma->dma);
free_irq(sdma->irq, sdma);
irq_dispose_mapping(sdma->irq);
+ pm_runtime_disable(&op->dev);
+ if (!pm_runtime_status_suspended(&op->dev))
+ sirfsoc_dma_runtime_suspend(&op->dev);
+
+ return 0;
+}
+
+static int sirfsoc_dma_runtime_suspend(struct device *dev)
+{
+ struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(sdma->clk);
+ return 0;
+}
+
+static int sirfsoc_dma_runtime_resume(struct device *dev)
+{
+ struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(sdma->clk);
+ if (ret < 0) {
+ dev_err(dev, "clk_enable failed: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int sirfsoc_dma_pm_suspend(struct device *dev)
+{
+ struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+ struct sirfsoc_dma_regs *save = &sdma->regs_save;
+ struct sirfsoc_dma_desc *sdesc;
+ struct sirfsoc_dma_chan *schan;
+ int ch;
+ int ret;
+
+ /*
+ * if we were runtime-suspended before, resume to enable clock
+ * before accessing register
+ */
+ if (pm_runtime_status_suspended(dev)) {
+ ret = sirfsoc_dma_runtime_resume(dev);
+ if (ret < 0)
+ return ret;
+ }
+
+ /*
+ * DMA controller will lose all registers while suspending
+ * so we need to save registers for active channels
+ */
+ for (ch = 0; ch < SIRFSOC_DMA_CHANNELS; ch++) {
+ schan = &sdma->channels[ch];
+ if (list_empty(&schan->active))
+ continue;
+ sdesc = list_first_entry(&schan->active,
+ struct sirfsoc_dma_desc,
+ node);
+ save->ctrl[ch] = readl_relaxed(sdma->base +
+ ch * 0x10 + SIRFSOC_DMA_CH_CTRL);
+ }
+ save->interrupt_en = readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN);
+
+ /* Disable clock */
+ sirfsoc_dma_runtime_suspend(dev);
+
+ return 0;
+}
+
+static int sirfsoc_dma_pm_resume(struct device *dev)
+{
+ struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+ struct sirfsoc_dma_regs *save = &sdma->regs_save;
+ struct sirfsoc_dma_desc *sdesc;
+ struct sirfsoc_dma_chan *schan;
+ int ch;
+ int ret;
+
+ /* Enable clock before accessing register */
+ ret = sirfsoc_dma_runtime_resume(dev);
+ if (ret < 0)
+ return ret;
+
+ writel_relaxed(save->interrupt_en, sdma->base + SIRFSOC_DMA_INT_EN);
+ for (ch = 0; ch < SIRFSOC_DMA_CHANNELS; ch++) {
+ schan = &sdma->channels[ch];
+ if (list_empty(&schan->active))
+ continue;
+ sdesc = list_first_entry(&schan->active,
+ struct sirfsoc_dma_desc,
+ node);
+ writel_relaxed(sdesc->width,
+ sdma->base + SIRFSOC_DMA_WIDTH_0 + ch * 4);
+ writel_relaxed(sdesc->xlen,
+ sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_XLEN);
+ writel_relaxed(sdesc->ylen,
+ sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_YLEN);
+ writel_relaxed(save->ctrl[ch],
+ sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_CTRL);
+ writel_relaxed(sdesc->addr >> 2,
+ sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_ADDR);
+ }
+
+ /* if we were runtime-suspended before, suspend again */
+ if (pm_runtime_status_suspended(dev))
+ sirfsoc_dma_runtime_suspend(dev);
+
return 0;
}
+static const struct dev_pm_ops sirfsoc_dma_pm_ops = {
+ SET_RUNTIME_PM_OPS(sirfsoc_dma_runtime_suspend, sirfsoc_dma_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(sirfsoc_dma_pm_suspend, sirfsoc_dma_pm_resume)
+};
+
static struct of_device_id sirfsoc_dma_match[] = {
{ .compatible = "sirf,prima2-dmac", },
{ .compatible = "sirf,marco-dmac", },
@@ -766,6 +891,7 @@ static struct platform_driver sirfsoc_dma_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
+ .pm = &sirfsoc_dma_pm_ops,
.of_match_table = sirfsoc_dma_match,
},
};
--
1.8.2.3
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