[PATCH 3/5] usb: phy: add Broadcom Kona USB control driver

[Matt Porter <matt.porter@linaro.org>]

Broadcom BCM281xx parts have a PHY control block that
operates in conjunction with the DWC2 USB OTG. This driver
exposes an API that allows control of power/reset for a
connected USB PHY.

Signed-off-by: Matt Porter <matt.porter@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
---
 .../devicetree/bindings/usb/bcm-kona-usb-ctrl.txt  |  12 ++
 drivers/usb/phy/Kconfig                            |   5 +
 drivers/usb/phy/Makefile                           |   1 +
 drivers/usb/phy/bcm-kona-usb.h                     |  31 +++++
 drivers/usb/phy/phy-bcm-kona-ctrl.c                | 151 +++++++++++++++++++++
 5 files changed, 200 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/bcm-kona-usb-ctrl.txt
 create mode 100644 drivers/usb/phy/bcm-kona-usb.h
 create mode 100644 drivers/usb/phy/phy-bcm-kona-ctrl.c

diff --git a/Documentation/devicetree/bindings/usb/bcm-kona-usb-ctrl.txt b/Documentation/devicetree/bindings/usb/bcm-kona-usb-ctrl.txt
new file mode 100644
index 0000000..98163f6
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/bcm-kona-usb-ctrl.txt
@@ -0,0 +1,12 @@
+BROADCOM KONA USB CONTROL
+
+Required properties:
+ - compatible: brcm,kona-ctrl-usb
+ - reg: offset and length of the USB control registers
+
+Example:
+
+	usbctl: usbctl@3f130000 {
+		compatible = "brcm,kona-ctrl-usb";
+		reg = <0x3f130000 0x28>;
+	};
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index d5589f9..2b7b4f1 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -100,6 +100,11 @@ config AM335X_PHY_USB
 	  This driver provides PHY support for that phy which part for the
 	  AM335x SoC.
 
+config BCM_KONA_CTRL_USB
+	tristate
+	help
+	  Enable this to support the Broadcom Kona USB control block
+
 config SAMSUNG_USBPHY
 	tristate
 	help
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 2135e85..98c545e 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_NOP_USB_XCEIV)		+= phy-generic.o
 obj-$(CONFIG_OMAP_CONTROL_USB)		+= phy-omap-control.o
 obj-$(CONFIG_AM335X_CONTROL_USB)	+= phy-am335x-control.o
 obj-$(CONFIG_AM335X_PHY_USB)		+= phy-am335x.o
+obj-$(CONFIG_BCM_KONA_CTRL_USB)		+= phy-bcm-kona-ctrl.o
 obj-$(CONFIG_OMAP_USB2)			+= phy-omap-usb2.o
 obj-$(CONFIG_OMAP_USB3)			+= phy-omap-usb3.o
 obj-$(CONFIG_SAMSUNG_USBPHY)		+= phy-samsung-usb.o
diff --git a/drivers/usb/phy/bcm-kona-usb.h b/drivers/usb/phy/bcm-kona-usb.h
new file mode 100644
index 0000000..4563dd6
--- /dev/null
+++ b/drivers/usb/phy/bcm-kona-usb.h
@@ -0,0 +1,31 @@
+/*
+ * bcm_kona_usb.h -- Broadcom Kona USB header file
+ *
+ * Copyright (C) 2013 Linaro Limited
+ * Matt Porter <matt.porter@linaro.org>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __BCM_KONA_USB_H
+#define __BCM_KONA_USB_H
+
+#include <linux/usb/phy.h>
+
+struct bcm_kona_usb {
+	struct usb_phy phy;
+	struct device *dev;
+	struct device *ctrl_dev;
+};
+
+extern struct device *bcm_kona_get_ctrl_dev(void);
+extern void bcm_kona_ctrl_usb_phy_power(struct device *, int);
+
+#endif /* __BCM_KONA_USB_H */
diff --git a/drivers/usb/phy/phy-bcm-kona-ctrl.c b/drivers/usb/phy/phy-bcm-kona-ctrl.c
new file mode 100644
index 0000000..d2936b6
--- /dev/null
+++ b/drivers/usb/phy/phy-bcm-kona-ctrl.c
@@ -0,0 +1,151 @@
+/*
+ * phy-bcm-kona-ctrl.c - Broadcom Kona USB Control Driver
+ *
+ * Based on phy-omap-control.c
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ * Copyright (C) 2013 Linaro Limited
+ * Matt Porter <matt.porter@linaro.org>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+
+#include "bcm-kona-usb.h"
+
+#define OTGCTL_OTGSTAT2		(1 << 31)
+#define OTGCTL_OTGSTAT1		(1 << 30)
+#define OTGCTL_PRST_N_SW	(1 << 11)
+#define OTGCTL_HRESET_N		(1 << 10)
+#define OTGCTL_UTMI_LINE_STATE1	(1 << 9)
+#define OTGCTL_UTMI_LINE_STATE0	(1 << 8)
+
+#define P1CTL_SOFT_RESET	(1 << 1)
+#define P1CTL_NON_DRIVING	(1 << 0)
+
+struct bcm_kona_usb_ctrl_regs {
+	u32 ctrl;
+	u32 cfg;
+	u32 p1ctl;
+	u32 status;
+	u32 bc_cfg;
+	u32 tp_in;
+	u32 tp_out;
+	u32 phy_ctrl;
+	u32 usbreg;
+	u32 usbproben;
+};
+
+struct bcm_kona_ctrl_usb {
+	struct device *dev;
+	struct bcm_kona_usb_ctrl_regs *regs;
+};
+
+static struct bcm_kona_ctrl_usb *ctrl_usb;
+
+/**
+ * bcm_kona_ctrl_dev - returns the device pointer for this control device
+ *
+ * This API should be called to get the device pointer for the Kona USB
+ * control device. This device pointer should be used when calling the
+ * exported bcm_kona_ctrl_usb_phy_power() API.
+ */
+struct device *bcm_kona_get_ctrl_dev(void)
+{
+	if (!ctrl_usb)
+		return ERR_PTR(-ENODEV);
+
+	return ctrl_usb->dev;
+}
+EXPORT_SYMBOL_GPL(bcm_kona_get_ctrl_dev);
+
+/**
+ * bcm_kona_ctrl_usb_phy_power - power on/off the phy using control module reg
+ * @dev: the control module device
+ * @on: 0 or 1, based on powering on or off the PHY
+ */
+void bcm_kona_ctrl_usb_phy_power(struct device *dev, int on)
+{
+	struct bcm_kona_ctrl_usb *ctrl = dev_get_drvdata(dev);
+	u32 val;
+
+	val = readl(&ctrl->regs->ctrl);
+	if (on) {
+		/* Configure and power PHY */
+		val &= ~(OTGCTL_OTGSTAT2 | OTGCTL_OTGSTAT1 |
+			 OTGCTL_UTMI_LINE_STATE1 | OTGCTL_UTMI_LINE_STATE0);
+		val |= OTGCTL_PRST_N_SW | OTGCTL_HRESET_N;
+		writel(val, &ctrl->regs->ctrl);
+
+		/* Soft reset PHY */
+		val = readl(&ctrl->regs->p1ctl);
+		val &= ~P1CTL_NON_DRIVING;
+		val |= P1CTL_SOFT_RESET;
+		writel(val, &ctrl->regs->p1ctl);
+		writel(val & ~P1CTL_SOFT_RESET, &ctrl->regs->p1ctl);
+		/* Reset needs to be asserted for 2ms */
+		mdelay(2);
+		writel(val | P1CTL_SOFT_RESET, &ctrl->regs->p1ctl);
+	} else {
+		val &= ~(OTGCTL_PRST_N_SW | OTGCTL_HRESET_N);
+		writel(val, &ctrl->regs->ctrl);
+	}
+}
+EXPORT_SYMBOL_GPL(bcm_kona_ctrl_usb_phy_power);
+
+static int bcm_kona_ctrl_usb_probe(struct platform_device *pdev)
+{
+	struct resource	*res;
+
+	ctrl_usb = devm_kzalloc(&pdev->dev, sizeof(*ctrl_usb), GFP_KERNEL);
+	if (!ctrl_usb) {
+		dev_err(&pdev->dev, "unable to alloc memory for control usb\n");
+		return -ENOMEM;
+	}
+
+	ctrl_usb->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ctrl_usb->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ctrl_usb->regs))
+		return PTR_ERR(ctrl_usb->regs);
+
+	dev_set_drvdata(ctrl_usb->dev, ctrl_usb);
+
+	return 0;
+}
+
+static const struct of_device_id bcm_kona_ctrl_usb_id_table[] = {
+	{ .compatible = "brcm,kona-ctrl-usb" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bcm_kona_ctrl_usb_id_table);
+
+static struct platform_driver bcm_kona_ctrl_usb_driver = {
+	.probe		= bcm_kona_ctrl_usb_probe,
+	.driver		= {
+		.name	= "bcm-kona-ctrl-usb",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(bcm_kona_ctrl_usb_id_table),
+	},
+};
+
+module_platform_driver(bcm_kona_ctrl_usb_driver);
+
+MODULE_ALIAS("platform:bcm-kona-ctrl-usb");
+MODULE_AUTHOR("Matt Porter");
+MODULE_DESCRIPTION("Broadcom Kona USB Control Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.4