mmc: Add runtime and system-wide PM to the TMIO MMC driver

Add runtime and system-wide power management to the TMIO MMC driver
in PIO and DMA modes, allowing it to properly save and restore its
state during system suspend. Runtime PM is very crude ATM, because
the controller has to be powered on all the time to detect card
hotplug events.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 54 insertions, 3 deletions

diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 710339a85c84..8b05d3ceb29c 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -39,6 +39,7 @@
 #include <linux/module.h>
 #include <linux/pagemap.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/scatterlist.h>
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
@@ -834,12 +835,17 @@ int __devinit tmio_mmc_host_probe(struct tmio_mmc_host **host,
         else
                 mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
 
+        pm_runtime_enable(&pdev->dev);
+        ret = pm_runtime_resume(&pdev->dev);
+        if (ret < 0)
+                goto pm_disable;
+
         tmio_mmc_clk_stop(_host);
         tmio_mmc_reset(_host);
 
         ret = platform_get_irq(pdev, 0);
         if (ret < 0)
-                goto unmap_ctl;
+                goto pm_suspend;
 
         _host->irq = ret;
 
@@ -850,7 +856,7 @@ int __devinit tmio_mmc_host_probe(struct tmio_mmc_host **host,
         ret = request_irq(_host->irq, tmio_mmc_irq, IRQF_DISABLED |
                 IRQF_TRIGGER_FALLING, dev_name(&pdev->dev), _host);
         if (ret)
-                goto unmap_ctl;
+                goto pm_suspend;
 
         spin_lock_init(&_host->lock);
 
@@ -860,6 +866,9 @@ int __devinit tmio_mmc_host_probe(struct tmio_mmc_host **host,
         /* See if we also get DMA */
         tmio_mmc_request_dma(_host, pdata);
 
+        /* We have to keep the device powered for its card detection to work */
+        pm_runtime_get_noresume(&pdev->dev);
+
         mmc_add_host(mmc);
 
         /* Unmask the IRQs we want to know about */
@@ -874,7 +883,10 @@ int __devinit tmio_mmc_host_probe(struct tmio_mmc_host **host,
 
         return 0;
 
-unmap_ctl:
+pm_suspend:
+        pm_runtime_suspend(&pdev->dev);
+pm_disable:
+        pm_runtime_disable(&pdev->dev);
         iounmap(_host->ctl);
 host_free:
         mmc_free_host(mmc);
@@ -885,13 +897,52 @@ EXPORT_SYMBOL(tmio_mmc_host_probe);
 
 void tmio_mmc_host_remove(struct tmio_mmc_host *host)
 {
+        struct platform_device *pdev = host->pdev;
+
         mmc_remove_host(host->mmc);
         cancel_delayed_work_sync(&host->delayed_reset_work);
         tmio_mmc_release_dma(host);
         free_irq(host->irq, host);
         iounmap(host->ctl);
         mmc_free_host(host->mmc);
+
+        /* Compensate for pm_runtime_get_sync() in probe() above */
+        pm_runtime_put_sync(&pdev->dev);
+        pm_runtime_disable(&pdev->dev);
 }
 EXPORT_SYMBOL(tmio_mmc_host_remove);
 
+#ifdef CONFIG_PM
+int tmio_mmc_host_suspend(struct device *dev)
+{
+        struct mmc_host *mmc = dev_get_drvdata(dev);
+        struct tmio_mmc_host *host = mmc_priv(mmc);
+        int ret = mmc_suspend_host(mmc);
+
+        if (!ret)
+                tmio_mmc_disable_mmc_irqs(host, TMIO_MASK_ALL);
+
+        host->pm_error = pm_runtime_put_sync(dev);
+
+        return ret;
+}
+EXPORT_SYMBOL(tmio_mmc_host_suspend);
+
+int tmio_mmc_host_resume(struct device *dev)
+{
+        struct mmc_host *mmc = dev_get_drvdata(dev);
+        struct tmio_mmc_host *host = mmc_priv(mmc);
+
+        if (!host->pm_error)
+                pm_runtime_get_sync(dev);
+
+        tmio_mmc_reset(mmc_priv(mmc));
+        tmio_mmc_request_dma(host, host->pdata);
+
+        return mmc_resume_host(mmc);
+}
+EXPORT_SYMBOL(tmio_mmc_host_resume);
+
+#endif  /* CONFIG_PM */
+
 MODULE_LICENSE("GPL v2");