ata/ahci_platform: Add clock framework support

On many architectures, drivers are supposed to prepare/unprepare &
enable/disable functional clock of device. This patch adds clock support for
ahci_platform.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

2 files changed, 52 insertions, 7 deletions

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 6441cbecfa1d..9be471200a07 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -35,6 +35,7 @@
 #ifndef _AHCI_H
 #define _AHCI_H
 
+#include <linux/clk.h>
 #include <linux/libata.h>
 
 /* Enclosure Management Control */
@@ -316,6 +317,7 @@ struct ahci_host_priv {
         u32                     em_loc; /* enclosure management location */
         u32                     em_buf_sz;      /* EM buffer size in byte */
         u32                     em_msg_type;    /* EM message type */
+        struct clk              *clk;           /* Only for platforms supporting clk */
 };
 
 extern int ahci_ignore_sss;
diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index dc187c746649..b1ae48054dc5 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -12,6 +12,7 @@
  * any later version.
  */
 
+#include <linux/clk.h>
 #include <linux/kernel.h>
 #include <linux/gfp.h>
 #include <linux/module.h>
@@ -118,6 +119,17 @@ static int __init ahci_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
 
+        hpriv->clk = clk_get(dev, NULL);
+        if (IS_ERR(hpriv->clk)) {
+                dev_err(dev, "can't get clock\n");
+        } else {
+                rc = clk_prepare_enable(hpriv->clk);
+                if (rc) {
+                        dev_err(dev, "clock prepare enable failed");
+                        goto free_clk;
+                }
+        }
+
         /*
          * Some platforms might need to prepare for mmio region access,
          * which could be done in the following init call. So, the mmio
@@ -127,7 +139,7 @@ static int __init ahci_probe(struct platform_device *pdev)
         if (pdata && pdata->init) {
                 rc = pdata->init(dev, hpriv->mmio);
                 if (rc)
-                        return rc;
+                        goto disable_unprepare_clk;
         }
 
         ahci_save_initial_config(dev, hpriv,
@@ -153,7 +165,7 @@ static int __init ahci_probe(struct platform_device *pdev)
         host = ata_host_alloc_pinfo(dev, ppi, n_ports);
         if (!host) {
                 rc = -ENOMEM;
-                goto err0;
+                goto pdata_exit;
         }
 
         host->private_data = hpriv;
@@ -183,7 +195,7 @@ static int __init ahci_probe(struct platform_device *pdev)
 
         rc = ahci_reset_controller(host);
         if (rc)
-                goto err0;
+                goto pdata_exit;
 
         ahci_init_controller(host);
         ahci_print_info(host, "platform");
@@ -191,12 +203,18 @@ static int __init ahci_probe(struct platform_device *pdev)
         rc = ata_host_activate(host, irq, ahci_interrupt, IRQF_SHARED,
                                &ahci_platform_sht);
         if (rc)
-                goto err0;
+                goto pdata_exit;
 
         return 0;
-err0:
+pdata_exit:
         if (pdata && pdata->exit)
                 pdata->exit(dev);
+disable_unprepare_clk:
+        if (!IS_ERR(hpriv->clk))
+                clk_disable_unprepare(hpriv->clk);
+free_clk:
+        if (!IS_ERR(hpriv->clk))
+                clk_put(hpriv->clk);
         return rc;
 }
 
@@ -205,12 +223,18 @@ static int __devexit ahci_remove(struct platform_device *pdev)
         struct device *dev = &pdev->dev;
         struct ahci_platform_data *pdata = dev_get_platdata(dev);
         struct ata_host *host = dev_get_drvdata(dev);
+        struct ahci_host_priv *hpriv = host->private_data;
 
         ata_host_detach(host);
 
         if (pdata && pdata->exit)
                 pdata->exit(dev);
 
+        if (!IS_ERR(hpriv->clk)) {
+                clk_disable_unprepare(hpriv->clk);
+                clk_put(hpriv->clk);
+        }
+
         return 0;
 }
 
@@ -245,6 +269,10 @@ static int ahci_suspend(struct device *dev)
 
         if (pdata && pdata->suspend)
                 return pdata->suspend(dev);
+
+        if (!IS_ERR(hpriv->clk))
+                clk_disable_unprepare(hpriv->clk);
+
         return 0;
 }
 
@@ -252,18 +280,27 @@ static int ahci_resume(struct device *dev)
 {
         struct ahci_platform_data *pdata = dev_get_platdata(dev);
         struct ata_host *host = dev_get_drvdata(dev);
+        struct ahci_host_priv *hpriv = host->private_data;
         int rc;
 
+        if (!IS_ERR(hpriv->clk)) {
+                rc = clk_prepare_enable(hpriv->clk);
+                if (rc) {
+                        dev_err(dev, "clock prepare enable failed");
+                        return rc;
+                }
+        }
+
         if (pdata && pdata->resume) {
                 rc = pdata->resume(dev);
                 if (rc)
-                        return rc;
+                        goto disable_unprepare_clk;
         }
 
         if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
                 rc = ahci_reset_controller(host);
                 if (rc)
-                        return rc;
+                        goto disable_unprepare_clk;
 
                 ahci_init_controller(host);
         }
@@ -271,6 +308,12 @@ static int ahci_resume(struct device *dev)
         ata_host_resume(host);
 
         return 0;
+
+disable_unprepare_clk:
+        if (!IS_ERR(hpriv->clk))
+                clk_disable_unprepare(hpriv->clk);
+
+        return rc;
 }
 #endif