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>

drivers/mmc/host/sh_mobile_sdhi.c

@@ -143,10 +143,16 @@ static int sh_mobile_sdhi_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct dev_pm_ops tmio_mmc_dev_pm_ops = {
+	.suspend = tmio_mmc_host_suspend,
+	.resume = tmio_mmc_host_resume,
+};
+
 static struct platform_driver sh_mobile_sdhi_driver = {
 	.driver		= {
 		.name	= "sh_mobile_sdhi",
 		.owner	= THIS_MODULE,
+		.pm	= &tmio_mmc_dev_pm_ops,
 	},
 	.probe		= sh_mobile_sdhi_probe,
 	.remove		= __devexit_p(sh_mobile_sdhi_remove),

drivers/mmc/host/tmio_mmc.c

@@ -30,7 +30,7 @@ static int tmio_mmc_suspend(struct platform_device *dev, pm_message_t state)
 	struct mmc_host *mmc = platform_get_drvdata(dev);
 	int ret;
 
-	ret = mmc_suspend_host(mmc);
+	ret = tmio_mmc_host_suspend(&dev->dev);
 
 	/* Tell MFD core it can disable us now.*/
 	if (!ret && cell->disable)
@@ -46,15 +46,12 @@ static int tmio_mmc_resume(struct platform_device *dev)
 	int ret = 0;
 
 	/* Tell the MFD core we are ready to be enabled */
-	if (cell->resume) {
+	if (cell->resume)
 		ret = cell->resume(dev);
-		if (ret)
-			goto out;
-	}
 
-	mmc_resume_host(mmc);
+	if (!ret)
+		ret = tmio_mmc_host_resume(&dev->dev);
 
-out:
 	return ret;
 }
 #else

drivers/mmc/host/tmio_mmc.h

@@ -51,6 +51,8 @@ struct tmio_mmc_host {
 	void (*set_pwr)(struct platform_device *host, int state);
 	void (*set_clk_div)(struct platform_device *host, int state);
 
+	int			pm_error;
+
 	/* pio related stuff */
 	struct scatterlist      *sg_ptr;
 	struct scatterlist      *sg_orig;
@@ -120,4 +122,12 @@ static inline void tmio_mmc_release_dma(struct tmio_mmc_host *host)
 }
 #endif
 
+#ifdef CONFIG_PM
+int tmio_mmc_host_suspend(struct device *dev);
+int tmio_mmc_host_resume(struct device *dev);
+#else
+#define tmio_mmc_host_suspend NULL
+#define tmio_mmc_host_resume NULL
+#endif
+
 #endif

drivers/mmc/host/tmio_mmc_dma.c

@@ -256,7 +256,10 @@ static bool tmio_mmc_filter(struct dma_chan *chan, void *arg)
 void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
 {
 	/* We can only either use DMA for both Tx and Rx or not use it at all */
-	if (pdata->dma) {
+	if (!pdata->dma)
+		return;
+
+	if (!host->chan_tx && !host->chan_rx) {
 		dma_cap_mask_t mask;
 
 		dma_cap_zero(mask);
@@ -284,18 +287,18 @@ void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdat
 
 		tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
 		tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
+	}
 
 	tmio_mmc_enable_dma(host, true);
 
 	return;
+
 ebouncebuf:
 	dma_release_channel(host->chan_rx);
 	host->chan_rx = NULL;
 ereqrx:
 	dma_release_channel(host->chan_tx);
 	host->chan_tx = NULL;
-		return;
-	}
 }
 
 void tmio_mmc_release_dma(struct tmio_mmc_host *host)

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");