drivers: phy: add generic PHY framework

The PHY framework provides a set of APIs to control a PHY. This API is
derived from the linux version of the generic PHY framework.
Currently the API supports init(), deinit(), power_on, power_off() and
reset(). The framework provides a way to get a reference to a phy from the
device-tree.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/phy/Kconfig

@@ -0,0 +1,36 @@
+
+menu "PHY Subsystem"
+
+config PHY
+	bool "PHY Core"
+	depends on DM
+	help
+	  PHY support.
+
+	  This framework is designed to provide a generic interface for PHY
+	  devices. PHY devices are dedicated hardware that handle the physical
+	  layer of the protocols in the OSI model.
+	  PHYs are commonly used for high speed interfaces such as Serial-ATA
+	  or PCI express.
+	  The API provides functions to initialize/deinitialize the
+	  PHY, power on/off the PHY, and reset the PHY. It's meant to be as
+	  compatible as possible with the equivalent framework found in the
+	  linux kernel.
+
+config SPL_PHY
+	bool "PHY Core in SPL"
+	depends on DM
+	help
+	  PHY support in SPL.
+
+	  This framework is designed to provide a generic interface for PHY
+	  devices. PHY devices are dedicated hardware that handle the physical
+	  layer of the protocols (https://en.wikipedia.org/wiki/OSI_model).
+	  PHYs are commonly used for high speed interfaces such as Serial-ATA
+	  or PCI express.
+	  The API provides functions to initialize/deinitialize the
+	  PHY, power on/off the PHY, and reset the PHY. It's meant to be as
+	  compatible as possible with the equivalent framework found in the
+	  linux kernel.
+
+endmenu

drivers/phy/Makefile

@@ -0,0 +1,8 @@
+#
+# Copyright (C) 2017 Texas Instruments Incorporated - http://www.ti.com/
+# Written by Jean-Jacques Hiblot  <jjhiblot@ti.com>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_$(SPL_)PHY) += phy-uclass.o

drivers/phy/phy-uclass.c

@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2017 Texas Instruments Incorporated - http://www.ti.com/
+ * Written by Jean-Jacques Hiblot  <jjhiblot@ti.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <generic-phy.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static inline struct phy_ops *phy_dev_ops(struct udevice *dev)
+{
+	return (struct phy_ops *)dev->driver->ops;
+}
+
+static int generic_phy_xlate_offs_flags(struct phy *phy,
+				 struct fdtdec_phandle_args *args)
+{
+	debug("%s(phy=%p)\n", __func__, phy);
+
+	if (args->args_count > 1) {
+		debug("Invaild args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+
+	if (args->args_count)
+		phy->id = args->args[0];
+	else
+		phy->id = 0;
+
+
+	return 0;
+}
+
+int generic_phy_get_by_index(struct udevice *dev, int index,
+			     struct phy *phy)
+{
+	struct fdtdec_phandle_args args;
+	struct phy_ops *ops;
+	int ret;
+	struct udevice *phydev;
+
+	debug("%s(dev=%p, index=%d, phy=%p)\n", __func__, dev, index, phy);
+
+	assert(phy);
+	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev_of_offset(dev),
+					     "phys", "#phy-cells", 0, index,
+					     &args);
+	if (ret) {
+		debug("%s: fdtdec_parse_phandle_with_args failed: err=%d\n",
+		      __func__, ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_of_offset(UCLASS_PHY, args.node, &phydev);
+	if (ret) {
+		debug("%s: uclass_get_device_by_of_offset failed: err=%d\n",
+		      __func__, ret);
+		return ret;
+	}
+
+	phy->dev = phydev;
+
+	ops = phy_dev_ops(phydev);
+
+	if (ops->of_xlate)
+		ret = ops->of_xlate(phy, &args);
+	else
+		ret = generic_phy_xlate_offs_flags(phy, &args);
+	if (ret) {
+		debug("of_xlate() failed: %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	return ret;
+}
+
+int generic_phy_get_by_name(struct udevice *dev, const char *phy_name,
+			    struct phy *phy)
+{
+	int index;
+
+	debug("%s(dev=%p, name=%s, phy=%p)\n", __func__, dev, phy_name, phy);
+
+	index = fdt_stringlist_search(gd->fdt_blob, dev_of_offset(dev),
+				      "phy-names", phy_name);
+	if (index < 0) {
+		debug("fdt_stringlist_search() failed: %d\n", index);
+		return index;
+	}
+
+	return generic_phy_get_by_index(dev, index, phy);
+}
+
+int generic_phy_init(struct phy *phy)
+{
+	struct phy_ops const *ops = phy_dev_ops(phy->dev);
+
+	return ops->init ? ops->init(phy) : 0;
+}
+
+int generic_phy_reset(struct phy *phy)
+{
+	struct phy_ops const *ops = phy_dev_ops(phy->dev);
+
+	return ops->reset ? ops->reset(phy) : 0;
+}
+
+int generic_phy_exit(struct phy *phy)
+{
+	struct phy_ops const *ops = phy_dev_ops(phy->dev);
+
+	return ops->exit ? ops->exit(phy) : 0;
+}
+
+int generic_phy_power_on(struct phy *phy)
+{
+	struct phy_ops const *ops = phy_dev_ops(phy->dev);
+
+	return ops->power_on ? ops->power_on(phy) : 0;
+}
+
+int generic_phy_power_off(struct phy *phy)
+{
+	struct phy_ops const *ops = phy_dev_ops(phy->dev);
+
+	return ops->power_off ? ops->power_off(phy) : 0;
+}
+
+UCLASS_DRIVER(phy) = {
+	.id		= UCLASS_PHY,
+	.name		= "phy",
+};