[PATCH 1/5] phy: add support for USB cluster on the Armada 375 SoC

[Gregory CLEMENT]

The Armada 375 SoC comes with an USB2 host and device controller and
an USB3 controller. The USB cluster control register allows to manage
common features of both USB controllers.

This commit adds a driver integrated in the generic PHY framework to
control this USB cluster feature.

Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
---
 drivers/phy/Kconfig                              |   6 +
 drivers/phy/Makefile                             |   1 +
 drivers/phy/phy-armada375-usb2.c                 | 140 +++++++++++++++++++++++
 include/dt-bindings/phy/armada-375-usb-cluster.h |  18 +++
 4 files changed, 165 insertions(+)
 create mode 100644 drivers/phy/phy-armada375-usb2.c
 create mode 100644 include/dt-bindings/phy/armada-375-usb-cluster.h

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 3bb05f17b9b4..e63cf9d15489 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -15,6 +15,12 @@ config GENERIC_PHY
 	  phy users can obtain reference to the PHY. All the users of this
 	  framework should select this config.
 
+config ARMADA375_USBCLUSTER_PHY
+	def_bool y
+	depends on MACH_ARMADA_375 || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+
 config PHY_EXYNOS_MIPI_VIDEO
 	tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
 	depends on HAS_IOMEM
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 2faf78edc864..47d5a86807b6 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -3,6 +3,7 @@
 #
 
 obj-$(CONFIG_GENERIC_PHY)		+= phy-core.o
+obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)	+= phy-armada375-usb2.o
 obj-$(CONFIG_BCM_KONA_USB2_PHY)		+= phy-bcm-kona-usb2.o
 obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)	+= phy-exynos-dp-video.o
 obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)	+= phy-exynos-mipi-video.o
diff --git a/drivers/phy/phy-armada375-usb2.c b/drivers/phy/phy-armada375-usb2.c
new file mode 100644
index 000000000000..6f8b274693de
--- /dev/null
+++ b/drivers/phy/phy-armada375-usb2.c
@@ -0,0 +1,140 @@
+/*
+ * USB cluster support for Armada 375 platform.
+ *
+ * Copyright (C) 2014 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2 or later. This program is licensed "as is"
+ * without any warranty of any kind, whether express or implied.
+ *
+ * Armada 375 comes with an USB2 host and device controller and an
+ * USB3 controller. The USB cluster control register allows to manage
+ * common features of both USB controllers.
+ */
+
+#include <dt-bindings/phy/armada-375-usb-cluster.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+#define USB2_PHY_CONFIG_DISABLE BIT(0)
+
+struct armada375_cluster_phy {
+	struct phy *phy;
+	void __iomem *reg;
+	bool use_usb3;
+	bool phy_provided;
+};
+
+static struct armada375_cluster_phy usb_cluster_phy;
+
+static int armada375_usb_phy_init(struct phy *phy)
+{
+	struct armada375_cluster_phy *cluster_phy = phy_get_drvdata(phy);
+	u32 reg;
+
+	reg = readl(cluster_phy->reg);
+	if (cluster_phy->use_usb3)
+		reg |= USB2_PHY_CONFIG_DISABLE;
+	else
+		reg &= ~USB2_PHY_CONFIG_DISABLE;
+	writel(reg, cluster_phy->reg);
+
+	return 0;
+}
+
+static struct phy_ops armada375_usb_phy_ops = {
+	.init = armada375_usb_phy_init,
+	.owner		= THIS_MODULE,
+};
+
+/*
+ * Only one controller can use this PHY. We shouldn't have the case
+ * when two controllers want to use this PHY. But if this case occurs
+ * then we provide a phy to the first one and return an error for the
+ * next one. This error has also to be an error returned by
+ * devm_phy_optional_get() so different from ENODEV for USB2. In the
+ * USB3 case it still optional and we use ENODEV.
+ */
+static struct phy *armada375_usb_phy_xlate(struct device *dev,
+					struct of_phandle_args *args)
+{
+	if (WARN_ON(usb_cluster_phy.phy_provided)) {
+		dev_err(dev, "This PHY has already been provided!\n");
+		dev_err(dev, "Check your device tree, only one controller can use it\n.");
+		if (args->args[0] == PHY_USB2)
+			return ERR_PTR(-EBUSY);
+		else
+			return ERR_PTR(-ENODEV);
+	}
+
+	if (args->args[0] == PHY_USB2)
+		usb_cluster_phy.use_usb3 = false;
+	else if (args->args[0] == PHY_USB3)
+		usb_cluster_phy.use_usb3 = true;
+	else {
+		dev_err(dev, "Invalid PHY mode\n");
+		return ERR_PTR(-ENODEV);
+	}
+
+	usb_cluster_phy.phy_provided = true;
+
+	return usb_cluster_phy.phy;
+}
+
+static int armada375_usb_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct phy *phy;
+	struct phy_provider *phy_provider;
+	void __iomem *usb_cluster_base;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	usb_cluster_base = devm_ioremap_resource(&pdev->dev, res);
+	if (!usb_cluster_base)
+		return -ENOMEM;
+
+	phy = devm_phy_create(dev, &armada375_usb_phy_ops, NULL);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "failed to create PHY \n");
+		return PTR_ERR(phy);
+	}
+
+	usb_cluster_phy.phy = phy;
+	usb_cluster_phy.reg = usb_cluster_base;
+	phy_set_drvdata(phy, &usb_cluster_phy);
+
+	phy_provider = devm_of_phy_provider_register(&pdev->dev,
+						     armada375_usb_phy_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
+
+	return 0;
+}
+
+static const struct of_device_id of_usb_cluster_table[] = {
+	{ .compatible = "marvell,armada-375-usb-cluster", },
+	{ /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, of_usb_cluster_table);
+
+static struct platform_driver armada375_usb_phy_driver = {
+	.probe	= armada375_usb_phy_probe,
+	.driver = {
+		.of_match_table	= of_usb_cluster_table,
+		.name  = "armada-375-usb-cluster",
+		.owner = THIS_MODULE,
+	}
+};
+module_platform_driver(armada375_usb_phy_driver);
+
+MODULE_DESCRIPTION("Armada 375 USB cluster driver");
+MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/phy/armada-375-usb-cluster.h b/include/dt-bindings/phy/armada-375-usb-cluster.h
new file mode 100644
index 000000000000..8cf037bb6408
--- /dev/null
+++ b/include/dt-bindings/phy/armada-375-usb-cluster.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (C) 2014 Marvell
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ */
+
+#ifndef __ARMADA_375_USB_CLUSTER__
+#define __ARMADA_375_USB_CLUSTER__
+
+/* The supported mode passed through by the phandle are the following */
+
+#define PHY_USB2    0
+#define PHY_USB3    1
+
+#endif /* __DT_BINDINGS_CLOCK_R8A7791_H__ */
-- 
1.8.1.2

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