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>

4 files changed, 159 insertions, 0 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index a5a3ebcbdd2..0c0523a35f8 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -97,6 +97,16 @@ config SATA_AHCI_PLATFORM
 
 	  If unsure, say N.
 
+config SATA_PHY
+	bool "SATA PHY Framework"
+	default n
+	help
+	  This option enables the 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.
+
 config SATA_FSL
 	tristate "Freescale 3.0Gbps SATA support"
 	depends on FSL_SOC
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index c04d0fd038a..6eae7e733cb 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_SATA_INIC162X)	+= sata_inic162x.o
 obj-$(CONFIG_SATA_SIL24)	+= sata_sil24.o
 obj-$(CONFIG_SATA_DWC)		+= sata_dwc_460ex.o
 obj-$(CONFIG_SATA_HIGHBANK)	+= sata_highbank.o libahci.o
+obj-$(CONFIG_SATA_PHY)		+= sata_phy.o
 
 # SFF w/ custom DMA
 obj-$(CONFIG_PDC_ADMA)		+= pdc_adma.o
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);
diff --git a/drivers/ata/sata_phy.h b/drivers/ata/sata_phy.h
new file mode 100644
index 00000000000..dc38683052e
--- /dev/null
+++ b/drivers/ata/sata_phy.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (c) 2010-2012 Samsung Electronics Co., Ltd.
+ *              http://www.samsung.com
+ *
+ * EXYNOS - SATA utility framework definitions.
+ *
+ * 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.
+*/
+
+enum sata_phy_type {
+	SATA_PHY_GENERATION1,
+	SATA_PHY_GENERATION2,
+	SATA_PHY_GENERATION3,
+};
+
+struct sata_phy {
+	int (*init) (struct sata_phy *);
+	int (*shutdown) (struct sata_phy *);
+	struct device *dev;
+	void *priv_data;
+	enum sata_phy_type type;
+	struct list_head head;
+};
+
+static inline int sata_init_phy(struct sata_phy *x)
+{
+	if (x && x->init)
+		return x->init(x);
+
+	return -EINVAL;
+}
+
+static inline void sata_shutdown_phy(struct sata_phy *x)
+{
+	if (x && x->shutdown)
+		x->shutdown(x);
+}
+
+struct sata_phy *sata_get_phy(enum sata_phy_type);
+int sata_add_phy(struct sata_phy *, enum sata_phy_type);
+void sata_remove_phy(struct sata_phy *);
+void sata_put_phy(struct sata_phy *);