ahci-platform: Add support for an optional regulator for sata-target power

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Documentation/devicetree/bindings/ata/ahci-platform.txt

@@ -11,6 +11,7 @@ Required properties:
 Optional properties:
 - dma-coherent      : Present if dma operations are coherent
 - clocks            : a list of phandle + clock specifier pairs
+- target-supply     : regulator for SATA target power
 
 Example:
         sata@ffe08000 {

drivers/ata/ahci.h

@@ -37,6 +37,7 @@
 
 #include <linux/clk.h>
 #include <linux/libata.h>
+#include <linux/regulator/consumer.h>
 
 /* Enclosure Management Control */
 #define EM_CTRL_MSG_TYPE              0x000f0000
@@ -323,6 +324,7 @@ struct ahci_host_priv {
 	u32			em_buf_sz;	/* EM buffer size in byte */
 	u32			em_msg_type;	/* EM message type */
 	struct clk		*clks[AHCI_MAX_CLKS]; /* Optional */
+	struct regulator	*target_pwr;	/* Optional */
 	void			*plat_data;	/* Other platform data */
 	/*
 	 * Optional ahci_start_engine override, if not set this gets set to the

drivers/ata/ahci_platform.c

@@ -185,6 +185,14 @@ static int ahci_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	hpriv->target_pwr = devm_regulator_get_optional(dev, "target");
+	if (IS_ERR(hpriv->target_pwr)) {
+		rc = PTR_ERR(hpriv->target_pwr);
+		if (rc == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		hpriv->target_pwr = NULL;
+	}
+
 	for (i = 0; i < AHCI_MAX_CLKS; i++) {
 		/*
 		 * For now we must use clk_get(dev, NULL) for the first clock,
@@ -206,9 +214,15 @@ static int ahci_probe(struct platform_device *pdev)
 		hpriv->clks[i] = clk;
 	}
 
+	if (hpriv->target_pwr) {
+		rc = regulator_enable(hpriv->target_pwr);
+		if (rc)
+			goto free_clk;
+	}
+
 	rc = ahci_enable_clks(dev, hpriv);
 	if (rc)
-		goto free_clk;
+		goto disable_regulator;
 
 	/*
 	 * Some platforms might need to prepare for mmio region access,
@@ -291,6 +305,9 @@ static int ahci_probe(struct platform_device *pdev)
 		pdata->exit(dev);
 disable_unprepare_clk:
 	ahci_disable_clks(hpriv);
+disable_regulator:
+	if (hpriv->target_pwr)
+		regulator_disable(hpriv->target_pwr);
 free_clk:
 	ahci_put_clks(hpriv);
 	return rc;
@@ -307,6 +324,9 @@ static void ahci_host_stop(struct ata_host *host)
 
 	ahci_disable_clks(hpriv);
 	ahci_put_clks(hpriv);
+
+	if (hpriv->target_pwr)
+		regulator_disable(hpriv->target_pwr);
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -343,6 +363,9 @@ static int ahci_suspend(struct device *dev)
 
 	ahci_disable_clks(hpriv);
 
+	if (hpriv->target_pwr)
+		regulator_disable(hpriv->target_pwr);
+
 	return 0;
 }
 
@@ -353,9 +376,15 @@ static int ahci_resume(struct device *dev)
 	struct ahci_host_priv *hpriv = host->private_data;
 	int rc;
 
+	if (hpriv->target_pwr) {
+		rc = regulator_enable(hpriv->target_pwr);
+		if (rc)
+			return rc;
+	}
+
 	rc = ahci_enable_clks(dev, hpriv);
 	if (rc)
-		return rc;
+		goto disable_regulator;
 
 	if (pdata && pdata->resume) {
 		rc = pdata->resume(dev);
@@ -377,6 +406,9 @@ static int ahci_resume(struct device *dev)
 
 disable_unprepare_clk:
 	ahci_disable_clks(hpriv);
+disable_regulator:
+	if (hpriv->target_pwr)
+		regulator_disable(hpriv->target_pwr);
 
 	return rc;
 }