ata: Add SATA PHY utility framework

This patch adds SATA PHY utility framework APIs. The framework acts as an
interface between the SATA device and the PHY device. The SATA PHY device
registers itself with the framework through the APIs provided and the SATA
device finds and requests for an appropriate PHY device.

Signed-off-by: Vasanth Ananthan <vasanth.a@samsung.com>

1 files changed, 104 insertions, 0 deletions

diff --git a/drivers/ata/sata_phy.c b/drivers/ata/sata_phy.c
new file mode 100644
index 00000000000..e5631a97951
--- /dev/null
+++ b/drivers/ata/sata_phy.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2010-2012 Samsung Electronics Co., Ltd.
+ *              http://www.samsung.com
+ *
+ * EXYNOS - SATA utility framework.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include "sata_phy.h"
+
+static LIST_HEAD(phy_list);
+static DEFINE_SPINLOCK(phy_lock);
+
+struct sata_phy *sata_get_phy(enum sata_phy_type type)
+{
+	struct sata_phy *x = NULL;
+	unsigned long flag;
+
+	if (list_empty(&phy_list))
+		return x;
+
+	spin_lock_irqsave(&phy_lock, flag);
+
+	list_for_each_entry(x, &phy_list, head) {
+		if (x->type == type) {
+			get_device(x->dev);
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&phy_lock, flag);
+	return x;
+}
+EXPORT_SYMBOL(sata_get_phy);
+
+int sata_add_phy(struct sata_phy *phy, enum sata_phy_type type)
+{
+	unsigned long flag;
+	unsigned int ret = -EINVAL;
+	struct sata_phy *x;
+
+	spin_lock_irqsave(&phy_lock, flag);
+
+	if (!phy)
+		return ret;
+
+	list_for_each_entry(x, &phy_list, head) {
+		if (x->type == type) {
+			dev_err(phy->dev, "transceiver type already exists\n");
+			goto out;
+		}
+	}
+	phy->type = type;
+	list_add_tail(&phy->head, &phy_list);
+	ret = 0;
+
+ out:
+	spin_unlock_irqrestore(&phy_lock, flag);
+	return ret;
+}
+EXPORT_SYMBOL(sata_add_phy);
+
+void sata_remove_phy(struct sata_phy *phy)
+{
+	unsigned long flag;
+	struct sata_phy *x;
+
+	spin_lock_irqsave(&phy_lock, flag);
+
+	if (!phy)
+		return;
+
+	list_for_each_entry(x, &phy_list, head) {
+		if (x->type == phy->type)
+			list_del(&phy->head);
+	}
+
+	spin_unlock_irqrestore(&phy_lock, flag);
+}
+EXPORT_SYMBOL(sata_remove_phy);
+
+void sata_put_phy(struct sata_phy *phy)
+{
+	unsigned long flag;
+
+	spin_lock_irqsave(&phy_lock, flag);
+
+	if (!phy)
+		return;
+
+	put_device(phy->dev);
+	spin_unlock_irqrestore(&phy_lock, flag);
+
+}
+EXPORT_SYMBOL(sata_put_phy);