dmaengine: shdma: add runtime- and system-level power management
Guennadi Liakhovetski [Fri, 29 Apr 2011 17:09:25 +0000 (17:09 +0000)]
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>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/dma/shdma.c
drivers/dma/shdma.h

index 727f51e..00b5f32 100644 (file)
@@ -1255,6 +1255,8 @@ rst_err:
        spin_unlock_irqrestore(&sh_dmae_lock, flags);
 
        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,
        },
 };
 
index 52e4fb1..3f9d3cd 100644 (file)
@@ -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 {