ata: ahci_platform: allow disabling of hotplug to save power

A number of resources remain powered to support hotplug. On platforms
I've worked with, allowing the ahci_platform to suspend saves about
150mW. This patch enables rpm and allows the device to be auto-suspended
through sysfs.

Signed-off-by: Samuel Morris <samorris@lexmark.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 99f9a89..7577293 100644 (file)
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -68,8 +68,13 @@ disable_resources:
        return rc;
 }
 
-static SIMPLE_DEV_PM_OPS(ahci_pm_ops, ahci_platform_suspend,
-                        ahci_platform_resume);
+#ifdef CONFIG_PM_SLEEP
+static const struct dev_pm_ops ahci_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(ahci_platform_suspend, ahci_platform_resume)
+       SET_RUNTIME_PM_OPS(ahci_platform_runtime_suspend,
+                       ahci_platform_runtime_resume, NULL)
+};
+#endif
 
 static const struct of_device_id ahci_of_match[] = {
        { .compatible = "generic-ahci", },
@@ -98,7 +103,9 @@ static struct platform_driver ahci_driver = {
                .name = DRV_NAME,
                .of_match_table = ahci_of_match,
                .acpi_match_table = ahci_acpi_match,
+#ifdef CONFIG_PM_SLEEP
                .pm = &ahci_pm_ops,
+#endif
        },
 };
 module_platform_driver(ahci_driver);

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index 30cc8f1..feee2e1 100644 (file)
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -257,7 +257,7 @@ static void ahci_platform_put_resources(struct device *dev, void *res)
        int c;
 
        if (hpriv->got_runtime_pm) {
-               pm_runtime_put_sync(dev);
+               pm_runtime_allow(dev);
                pm_runtime_disable(dev);
        }
 
@@ -475,8 +475,10 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
                if (rc == -EPROBE_DEFER)
                        goto err_out;
        }
+
+       pm_runtime_set_active(dev);
        pm_runtime_enable(dev);
-       pm_runtime_get_sync(dev);
+       pm_runtime_forbid(dev);
        hpriv->got_runtime_pm = true;
 
        devres_remove_group(dev, NULL);
@@ -705,6 +707,21 @@ int ahci_platform_resume_host(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(ahci_platform_resume_host);
 
+static int _ahci_platform_suspend(struct device *dev)
+{
+       struct ata_host *host = dev_get_drvdata(dev);
+       struct ahci_host_priv *hpriv = host->private_data;
+       int rc;
+
+       rc = ahci_platform_suspend_host(dev);
+       if (rc)
+               return rc;
+
+       ahci_platform_disable_resources(hpriv);
+
+       return 0;
+}
+
 /**
  * ahci_platform_suspend - Suspend an ahci-platform device
  * @dev: the platform device to suspend
@@ -716,20 +733,45 @@ EXPORT_SYMBOL_GPL(ahci_platform_resume_host);
  * 0 on success otherwise a negative error code
  */
 int ahci_platform_suspend(struct device *dev)
+{
+       return _ahci_platform_suspend(dev);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_suspend);
+
+/**
+ * ahci_platform_runtime_suspend - Runtime suspend an ahci-platform device
+ * @dev: the platform device to suspend
+ *
+ * This function suspends the host associated with the device, followed by
+ * disabling all the resources of the device.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_runtime_suspend(struct device *dev)
+{
+       return _ahci_platform_suspend(dev);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_runtime_suspend);
+
+static int _ahci_platform_resume(struct device *dev)
 {
        struct ata_host *host = dev_get_drvdata(dev);
        struct ahci_host_priv *hpriv = host->private_data;
        int rc;
 
-       rc = ahci_platform_suspend_host(dev);
+       rc = ahci_platform_enable_resources(hpriv);
        if (rc)
                return rc;
 
-       ahci_platform_disable_resources(hpriv);
+       rc = ahci_platform_resume_host(dev);
+       if (rc) {
+               ahci_platform_disable_resources(hpriv);
+               return rc;
+       }
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(ahci_platform_suspend);
 
 /**
  * ahci_platform_resume - Resume an ahci-platform device
@@ -743,31 +785,37 @@ EXPORT_SYMBOL_GPL(ahci_platform_suspend);
  */
 int ahci_platform_resume(struct device *dev)
 {
-       struct ata_host *host = dev_get_drvdata(dev);
-       struct ahci_host_priv *hpriv = host->private_data;
        int rc;
 
-       rc = ahci_platform_enable_resources(hpriv);
+       rc = _ahci_platform_resume(dev);
        if (rc)
                return rc;
 
-       rc = ahci_platform_resume_host(dev);
-       if (rc)
-               goto disable_resources;
-
        /* We resumed so update PM runtime state */
        pm_runtime_disable(dev);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);
 
        return 0;
-
-disable_resources:
-       ahci_platform_disable_resources(hpriv);
-
-       return rc;
 }
 EXPORT_SYMBOL_GPL(ahci_platform_resume);
+
+/**
+ * ahci_platform_runtime_resume - Runtime resume an ahci-platform device
+ * @dev: the platform device to resume
+ *
+ * This function enables all the resources of the device followed by
+ * resuming the host associated with the device.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_runtime_resume(struct device *dev)
+{
+       return _ahci_platform_resume(dev);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_runtime_resume);
+
 #endif
 
 MODULE_DESCRIPTION("AHCI SATA platform library");

diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h
index 1b0a17b..6396e69 100644 (file)
--- a/include/linux/ahci_platform.h
+++ b/include/linux/ahci_platform.h
@@ -42,5 +42,7 @@ int ahci_platform_suspend_host(struct device *dev);
 int ahci_platform_resume_host(struct device *dev);
 int ahci_platform_suspend(struct device *dev);
 int ahci_platform_resume(struct device *dev);
+int ahci_platform_runtime_suspend(struct device *dev);
+int ahci_platform_runtime_resume(struct device *dev);
 
 #endif /* _AHCI_PLATFORM_H */