[PATCH v4 3/4] ata: libahci: Allow using multiple regulators

[Gregory CLEMENT]

The current implementation of the libahci allows using multiple PHYs
but not multiple regulators. This patch adds the support of multiple
regulators. Until now it was mandatory to have a PHY under a subnode,
now a port subnode can contain either a regulator or a PHY (or both).

In order to be able to asociate a port with a regulator the port are
now a platform device in the device tree case.

There was only one driver which used directly the regulator field of
the ahci_host_priv structure. To preserve the bisectability the change
in the ahci_imx driver was done in the same patch.

Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
---
 drivers/ata/ahci.h             |   2 +-
 drivers/ata/ahci_imx.c         |  14 +--
 drivers/ata/libahci_platform.c | 230 +++++++++++++++++++++++++++++------------
 include/linux/ahci_platform.h  |   2 +
 4 files changed, 173 insertions(+), 75 deletions(-)

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 40f0e34f17af..275358ae0b3f 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -333,7 +333,7 @@ struct ahci_host_priv {
 	u32			em_msg_type;	/* EM message type */
 	bool			got_runtime_pm; /* Did we do pm_runtime_get? */
 	struct clk		*clks[AHCI_MAX_CLKS]; /* Optional */
-	struct regulator	*target_pwr;	/* Optional */
+	struct regulator	**target_pwrs;	/* Optional */
 	/*
 	 * If platform uses PHYs. There is a 1:1 relation between the port number and
 	 * the PHY position in this array.
diff --git a/drivers/ata/ahci_imx.c b/drivers/ata/ahci_imx.c
index 35d51c59a370..41632e57d46f 100644
--- a/drivers/ata/ahci_imx.c
+++ b/drivers/ata/ahci_imx.c
@@ -221,11 +221,9 @@ static int imx_sata_enable(struct ahci_host_priv *hpriv)
 	if (imxpriv->no_device)
 		return 0;
 
-	if (hpriv->target_pwr) {
-		ret = regulator_enable(hpriv->target_pwr);
-		if (ret)
-			return ret;
-	}
+	ret = ahci_platform_enable_regulators(hpriv);
+	if (ret)
+		return ret;
 
 	ret = clk_prepare_enable(imxpriv->sata_ref_clk);
 	if (ret < 0)
@@ -270,8 +268,7 @@ static int imx_sata_enable(struct ahci_host_priv *hpriv)
 disable_clk:
 	clk_disable_unprepare(imxpriv->sata_ref_clk);
 disable_regulator:
-	if (hpriv->target_pwr)
-		regulator_disable(hpriv->target_pwr);
+	ahci_platform_disable_regulators(hpriv);
 
 	return ret;
 }
@@ -291,8 +288,7 @@ static void imx_sata_disable(struct ahci_host_priv *hpriv)
 
 	clk_disable_unprepare(imxpriv->sata_ref_clk);
 
-	if (hpriv->target_pwr)
-		regulator_disable(hpriv->target_pwr);
+	ahci_platform_disable_regulators(hpriv);
 }
 
 static void ahci_imx_error_handler(struct ata_port *ap)
diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index a147aaadca85..73a086664ee7 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -24,6 +24,7 @@
 #include <linux/ahci_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/pm_runtime.h>
+#include <linux/of_platform.h>
 #include "ahci.h"
 
 static void ahci_host_stop(struct ata_host *host);
@@ -138,6 +139,59 @@ void ahci_platform_disable_clks(struct ahci_host_priv *hpriv)
 EXPORT_SYMBOL_GPL(ahci_platform_disable_clks);
 
 /**
+ * ahci_platform_enable_regulators - Enable regulators
+ * @hpriv: host private area to store config values
+ *
+ * This function enables all the regulators found in
+ * hpriv->target_pwrs, if any.  If a regulator fails to be enabled, it
+ * disables all the regulators already enabled in reverse order and
+ * returns an error.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv)
+{
+	int rc, i;
+
+	for (i = 0; i < hpriv->nports; i++) {
+		if (!hpriv->target_pwrs[i])
+			continue;
+
+		rc = regulator_enable(hpriv->target_pwrs[i]);
+		if (rc)
+			goto disable_target_pwrs;
+	}
+
+	return 0;
+
+disable_target_pwrs:
+	while (--i >= 0)
+		if (hpriv->target_pwrs[i])
+			regulator_disable(hpriv->target_pwrs[i]);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ahci_platform_enable_regulators);
+
+/**
+ * ahci_platform_disable_regulators - Disable regulators
+ * @hpriv: host private area to store config values
+ *
+ * This function disables all regulators found in hpriv->target_pwrs.
+ */
+void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv)
+{
+	int i;
+
+	for (i = 0; i < hpriv->nports; i++) {
+		if (!hpriv->target_pwrs[i])
+			continue;
+		regulator_disable(hpriv->target_pwrs[i]);
+	}
+}
+EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
+/**
  * ahci_platform_enable_resources - Enable platform resources
  * @hpriv: host private area to store config values
  *
@@ -157,11 +211,9 @@ int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
 {
 	int rc;
 
-	if (hpriv->target_pwr) {
-		rc = regulator_enable(hpriv->target_pwr);
-		if (rc)
-			return rc;
-	}
+	rc = ahci_platform_enable_regulators(hpriv);
+	if (rc)
+		return rc;
 
 	rc = ahci_platform_enable_clks(hpriv);
 	if (rc)
@@ -177,8 +229,8 @@ disable_clks:
 	ahci_platform_disable_clks(hpriv);
 
 disable_regulator:
-	if (hpriv->target_pwr)
-		regulator_disable(hpriv->target_pwr);
+	ahci_platform_disable_regulators(hpriv);
+
 	return rc;
 }
 EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
@@ -199,8 +251,7 @@ void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
 
 	ahci_platform_disable_clks(hpriv);
 
-	if (hpriv->target_pwr)
-		regulator_disable(hpriv->target_pwr);
+	ahci_platform_disable_regulators(hpriv);
 }
 EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
 
@@ -216,6 +267,68 @@ static void ahci_platform_put_resources(struct device *dev, void *res)
 
 	for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
 		clk_put(hpriv->clks[c]);
+	/*
+	 * The regulators are tied to child node device and not to the
+	 * SATA device itself. So we can't use devm for automatically
+	 * releasing them. We have to do it manually here.
+	 */
+	for (c = 0; c < hpriv->nports; c++)
+		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
+			regulator_put(hpriv->target_pwrs[c]);
+
+}
+
+static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port,
+				struct device *dev, struct device_node *node)
+{
+	int rc;
+
+	hpriv->phys[port] = devm_of_phy_get(dev, node, NULL);
+
+	if (!IS_ERR(hpriv->phys[port]))
+		return 0;
+
+	rc = PTR_ERR(hpriv->phys[port]);
+	switch (rc) {
+	case -ENOSYS:
+		/* No PHY support. Check if PHY is required. */
+		if (of_find_property(node, "phys", NULL)) {
+			dev_err(dev,
+				"couldn't get PHY in node %s: ENOSYS\n",
+				node->name);
+			break;
+		}
+	case -ENODEV:
+		/* continue normally */
+		hpriv->phys[port] = NULL;
+		rc = 0;
+		break;
+
+	default:
+		dev_err(dev,
+			"couldn't get PHY in node %s: %d\n",
+			node->name, rc);
+
+		break;
+	}
+
+	return rc;
+}
+
+static int ahci_platform_get_regulator(struct ahci_host_priv *hpriv, u32 port,
+				struct device *dev)
+{
+	struct regulator *target_pwr;
+	int rc = 0;
+
+	target_pwr = regulator_get_optional(dev, "target");
+
+	if (!IS_ERR(target_pwr))
+		hpriv->target_pwrs[port] = target_pwr;
+	else
+		rc = PTR_ERR(target_pwr);
+
+	return rc;
 }
 
 /**
@@ -240,7 +353,7 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
 	struct ahci_host_priv *hpriv;
 	struct clk *clk;
 	struct device_node *child;
-	int i, enabled_ports = 0, rc = -ENOMEM;
+	int i, sz, enabled_ports = 0, rc = -ENOMEM, child_nodes;
 	u32 mask_port_map = 0;
 
 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
@@ -261,14 +374,6 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
 		goto err_out;
 	}
 
-	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)
-			goto err_out;
-		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,
@@ -290,19 +395,33 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
 		hpriv->clks[i] = clk;
 	}
 
-	hpriv->nports = of_get_child_count(dev->of_node);
+	hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
 
-	if (hpriv->nports) {
-		hpriv->phys = devm_kzalloc(dev,
-					   hpriv->nports * sizeof(*hpriv->phys),
-					   GFP_KERNEL);
-		if (!hpriv->phys) {
-			rc = -ENOMEM;
-			goto err_out;
-		}
+	/*
+	 * If no sub-node was found, we still need to set nports to
+	 * one in order to be able to use the
+	 * ahci_platform_[en|dis]able_[phys|regulators] functions.
+	 */
+	if (!child_nodes)
+		hpriv->nports = 1;
 
+	sz = hpriv->nports * sizeof(*hpriv->phys);
+	hpriv->phys = devm_kzalloc(dev, sz, GFP_KERNEL);
+	if (!hpriv->phys) {
+		rc = -ENOMEM;
+		goto err_out;
+	}
+	sz = hpriv->nports * sizeof(*hpriv->target_pwrs);
+	hpriv->target_pwrs = devm_kzalloc(dev, sz, GFP_KERNEL);
+	if (!hpriv->target_pwrs) {
+		rc = -ENOMEM;
+		goto err_out;
+	}
+
+	if (child_nodes) {
 		for_each_child_of_node(dev->of_node, child) {
 			u32 port;
+			struct platform_device *port_dev;
 
 			if (!of_device_is_available(child))
 				continue;
@@ -316,18 +435,23 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
 				dev_warn(dev, "invalid port number %d\n", port);
 				continue;
 			}
-
 			mask_port_map |= BIT(port);
 
-			hpriv->phys[port] = devm_of_phy_get(dev, child, NULL);
-			if (IS_ERR(hpriv->phys[port])) {
-				rc = PTR_ERR(hpriv->phys[port]);
-				dev_err(dev,
-					"couldn't get PHY in node %s: %d\n",
-					child->name, rc);
-				goto err_out;
+			of_platform_device_create(child, NULL, NULL);
+
+			port_dev = of_find_device_by_node(child);
+
+			if (port_dev) {
+				rc = ahci_platform_get_regulator(hpriv, port,
+								&port_dev->dev);
+				if (rc == -EPROBE_DEFER)
+					goto err_out;
 			}
 
+			rc = ahci_platform_get_phy(hpriv, port, dev, child);
+			if (rc)
+				goto err_out;
+
 			enabled_ports++;
 		}
 		if (!enabled_ports) {
@@ -343,38 +467,14 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
 		 * If no sub-node was found, keep this for device tree
 		 * compatibility
 		 */
-		struct phy *phy = devm_phy_get(dev, "sata-phy");
-		if (!IS_ERR(phy)) {
-			hpriv->phys = devm_kzalloc(dev, sizeof(*hpriv->phys),
-						   GFP_KERNEL);
-			if (!hpriv->phys) {
-				rc = -ENOMEM;
-				goto err_out;
-			}
-
-			hpriv->phys[0] = phy;
-			hpriv->nports = 1;
-		} else {
-			rc = PTR_ERR(phy);
-			switch (rc) {
-				case -ENOSYS:
-					/* No PHY support. Check if PHY is required. */
-					if (of_find_property(dev->of_node, "phys", NULL)) {
-						dev_err(dev, "couldn't get sata-phy: ENOSYS\n");
-						goto err_out;
-					}
-				case -ENODEV:
-					/* continue normally */
-					hpriv->phys = NULL;
-					break;
-
-				default:
-					goto err_out;
+		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
+		if (rc)
+			goto err_out;
 
-			}
-		}
+		rc = ahci_platform_get_regulator(hpriv, 0, dev);
+		if (rc == -EPROBE_DEFER)
+			goto err_out;
 	}
-
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);
 	hpriv->got_runtime_pm = true;
diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h
index 642d6ae4030c..f65b33809170 100644
--- a/include/linux/ahci_platform.h
+++ b/include/linux/ahci_platform.h
@@ -24,6 +24,8 @@ struct platform_device;
 
 int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);
 void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);
+int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv);
+void ahci_platform_disable_regulators(struct ahci_host_priv *hpriv);
 int ahci_platform_enable_resources(struct ahci_host_priv *hpriv);
 void ahci_platform_disable_resources(struct ahci_host_priv *hpriv);
 struct ahci_host_priv *ahci_platform_get_resources(
-- 
1.9.1

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