[PATCH 2/2] dmaengine: shdma: add runtime- and system-level power management

Guennadi Liakhovetski
2011-04-29T17:09:52Z

This patch extends and fixes runtime power management in the shdma
driver to support powering down the DMA controller and adds support
for system-level suspend and resume.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
---
drivers/dma/shdma.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/dma/shdma.h | 1 +
2 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index d0f402b..dcc1b21 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -1254,6 +1254,8 @@ rst_err:
spin_unlock_irq(&sh_dmae_lock);

pm_runtime_put(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+
if (dmars)
iounmap(shdev->dmars);
emapdmars:
@@ -1313,12 +1315,78 @@ static void sh_dmae_shutdown(struct platform_device *pdev)
sh_dmae_ctl_stop(shdev);
}

+static int sh_dmae_runtime_suspend(struct device *dev)
+{
+ return 0;
+}
+
+static int sh_dmae_runtime_resume(struct device *dev)
+{
+ struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+
+ return sh_dmae_rst(shdev);
+}
+
+#ifdef CONFIG_PM
+static int sh_dmae_suspend(struct device *dev)
+{
+ struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < shdev->pdata->channel_num; i++) {
+ struct sh_dmae_chan *sh_chan = shdev->chan[i];
+ if (sh_chan->descs_allocated)
+ sh_chan->pm_error = pm_runtime_put_sync(dev);
+ }
+
+ return 0;
+}
+
+static int sh_dmae_resume(struct device *dev)
+{
+ struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < shdev->pdata->channel_num; i++) {
+ struct sh_dmae_chan *sh_chan = shdev->chan[i];
+ struct sh_dmae_slave *param = sh_chan->common.private;
+
+ if (!sh_chan->descs_allocated)
+ continue;
+
+ if (!sh_chan->pm_error)
+ pm_runtime_get_sync(dev);
+
+ if (param) {
+ const struct sh_dmae_slave_config *cfg = param->config;
+ dmae_set_dmars(sh_chan, cfg->mid_rid);
+ dmae_set_chcr(sh_chan, cfg->chcr);
+ } else {
+ dmae_init(sh_chan);
+ }
+ }
+
+ return 0;
+}
+#else
+#define sh_dmae_suspend NULL
+#define sh_dmae_resume NULL
+#endif
+
+const struct dev_pm_ops sh_dmae_pm = {
+ .suspend = sh_dmae_suspend,
+ .resume = sh_dmae_resume,
+ .runtime_suspend = sh_dmae_runtime_suspend,
+ .runtime_resume = sh_dmae_runtime_resume,
+};
+
static struct platform_driver sh_dmae_driver = {
.remove = __exit_p(sh_dmae_remove),
.shutdown = sh_dmae_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "sh-dma-engine",
+ .pm = &sh_dmae_pm,
},
};

diff --git a/drivers/dma/shdma.h b/drivers/dma/shdma.h
index 52e4fb1..3f9d3cd 100644
--- a/drivers/dma/shdma.h
+++ b/drivers/dma/shdma.h
@@ -37,6 +37,7 @@ struct sh_dmae_chan {
int id; /* Raw id of this channel */
u32 __iomem *base;
char dev_id[16]; /* unique name per DMAC of channel */
+ int pm_error;
};

struct sh_dmae_device {
--
1.7.2.5