[PATCH v1 2/2] usb: musb: pic32: Add USB DRC driver for PIC32 OTG controller.

[Purna Chandra Mandal]

From: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>

This driver adds support of PIC32 MUSB OTG controller as
dual role device. It implements platform specific glue to
reuse musb core.

Signed-off-by: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
Signed-off-by: Purna Chandra Mandal <purna.mandal@xxxxxxxxxxxxx>

---

 drivers/usb/musb/Kconfig  |   9 +-
 drivers/usb/musb/Makefile |   3 +-
 drivers/usb/musb/pic32.c  | 608 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 617 insertions(+), 3 deletions(-)
 create mode 100644 drivers/usb/musb/pic32.c

diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
index 886526b..705f8b8 100644
--- a/drivers/usb/musb/Kconfig
+++ b/drivers/usb/musb/Kconfig
@@ -112,6 +112,13 @@ config USB_MUSB_BLACKFIN
 	depends on (BF54x && !BF544) || (BF52x && ! BF522 && !BF523)
 	depends on NOP_USB_XCEIV
 
+config USB_MUSB_PIC32
+	tristate "Microchip PIC32 USB platforms"
+	depends on MACH_PIC32 || COMPILE_TEST
+	depends on NOP_USB_XCEIV
+	help
+	  Say y to enable PIC32 USB DRC controller support
+
 config USB_MUSB_UX500
 	tristate "Ux500 platforms"
 	depends on ARCH_U8500 || COMPILE_TEST
@@ -149,7 +156,7 @@ config USB_UX500_DMA
 
 config USB_INVENTRA_DMA
 	bool 'Inventra'
-	depends on USB_MUSB_OMAP2PLUS || USB_MUSB_BLACKFIN
+	depends on USB_MUSB_OMAP2PLUS || USB_MUSB_BLACKFIN || USB_MUSB_PIC32
 	help
 	  Enable DMA transfers using Mentor's engine.
 
diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
index f95befe..b9275cd 100644
--- a/drivers/usb/musb/Makefile
+++ b/drivers/usb/musb/Makefile
@@ -1,7 +1,6 @@
 #
 # for USB OTG silicon based on Mentor Graphics INVENTRA designs
 #
-
 obj-$(CONFIG_USB_MUSB_HDRC) += musb_hdrc.o
 
 musb_hdrc-y := musb_core.o
@@ -20,9 +19,9 @@ obj-$(CONFIG_USB_MUSB_DA8XX)			+= da8xx.o
 obj-$(CONFIG_USB_MUSB_BLACKFIN)			+= blackfin.o
 obj-$(CONFIG_USB_MUSB_UX500)			+= ux500.o
 obj-$(CONFIG_USB_MUSB_JZ4740)			+= jz4740.o
+obj-$(CONFIG_USB_MUSB_PIC32)			+= pic32.o
 obj-$(CONFIG_USB_MUSB_SUNXI)			+= sunxi.o
 
-
 obj-$(CONFIG_USB_MUSB_AM335X_CHILD)		+= musb_am335x.o
 
 # the kconfig must guarantee that only one of the
diff --git a/drivers/usb/musb/pic32.c b/drivers/usb/musb/pic32.c
new file mode 100644
index 0000000..3921088
--- /dev/null
+++ b/drivers/usb/musb/pic32.c
@@ -0,0 +1,608 @@
+/*
+ * Microchip PIC32 MUSB Dual-Role Controller "glue layer".
+ *
+ * Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
+ * Purna Chandra Mandal <purna.mandal@xxxxxxxxxxxxx>
+ * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
+ *
+ * Based on the am35x and dsps "glue layer" code.
+ *
+ * This program is free software; you can distribute it and/or modify it
+ * under the terms of the GNU General Public License (Version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/usb/of.h>
+
+#include "musb_core.h"
+
+#define MUSB_SOFTRST		0x7f
+#define  MUSB_SOFTRST_NRST      BIT(0)
+#define  MUSB_SOFTRST_NRSTX     BIT(1)
+
+/* USB Clock & Reset Control */
+#define USBCRCON		0x0
+#define  USBCRCON_USBWKUPEN	BIT(0)  /* Enable remote wakeup interrupt */
+#define  USBCRCON_USBRIE	BIT(1)  /* Enable Remote resume interrupt */
+#define  USBCRCON_USBIE		BIT(2)  /* Enable USB General interrupt */
+#define  USBCRCON_SENDMONEN     BIT(3)  /* Enable Session End VBUS monitoring */
+#define  USBCRCON_BSVALMONEN    BIT(4)  /* Enable B-Device VBUS monitoring */
+#define  USBCRCON_ASVALMONEN    BIT(5)  /* Enable A-Device VBUS monitoring */
+#define  USBCRCON_VBUSMONEN     BIT(6)  /* Enable VBUS monitoring */
+#define  USBCRCON_PHYIDEN	BIT(7)  /* Enabale USBPhy USBID monitoring */
+#define  USBCRCON_USBIDVAL	BIT(8)  /* USBID override value */
+#define  USBCRCON_USBIDOVEN	BIT(9)  /* Enable USBID override */
+#define  USBCRCON_USBWKUP	BIT(24) /* Remote wakeup status */
+#define  USBCRCON_USBRF		BIT(25) /* USB Remote resume status */
+#define  USBCRCON_USBIF		BIT(26) /* USB General interrupt status */
+
+#define PIC32_TX_EP_MASK	0xffff	/* EP0 + 15 Tx EPs */
+#define PIC32_RX_EP_MASK	0xfffe	/* 15 Rx EPs */
+
+#define	POLL_SECONDS		2
+
+struct pic32_musb {
+	void __iomem		*cru;
+	struct clk		*clk;
+	int			oc_irq;
+	struct platform_device	*platdev;
+	struct timer_list	timer;		/* otg_workaround timer */
+	unsigned long		last_timer;	/* last timer data for */
+};
+
+static irqreturn_t pic32_over_current(int irq, void *d)
+{
+	struct device *dev = d;
+
+	dev_err(dev, "USB Host over-current detected !\n");
+
+	return IRQ_HANDLED;
+}
+
+static void pic32_musb_enable(struct musb *musb)
+{
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue = dev_get_drvdata(dev->parent);
+
+	/* Enable additional interrupts */
+	enable_irq(glue->oc_irq);
+}
+
+static void pic32_musb_disable(struct musb *musb)
+{
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue = dev_get_drvdata(dev->parent);
+
+	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
+
+	/* Disable additional interrupts */
+	disable_irq(glue->oc_irq);
+}
+
+static void pic32_musb_set_vbus(struct musb *musb, int is_on)
+{
+	WARN_ON(is_on && is_peripheral_active(musb));
+}
+
+static void otg_timer(unsigned long _musb)
+{
+	struct musb *musb = (void *)_musb;
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue;
+	int skip_session = 0;
+	unsigned long flags;
+	u8 devctl;
+
+	glue = dev_get_drvdata(dev->parent);
+	/*
+	 * We poll because IP's won't expose several OTG-critical
+	 * status change events (from the transceiver) otherwise.
+	 */
+	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+	dev_dbg(dev, "Poll devctl %02x (%s)\n", devctl,
+		usb_otg_state_string(musb->xceiv->otg->state));
+
+	spin_lock_irqsave(&musb->lock, flags);
+	switch (musb->xceiv->otg->state) {
+	case OTG_STATE_A_WAIT_BCON:
+		musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
+		skip_session = 1;
+		/* fall */
+	case OTG_STATE_A_IDLE:
+	case OTG_STATE_B_IDLE:
+		if (devctl & MUSB_DEVCTL_BDEVICE) {
+			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
+			MUSB_DEV_MODE(musb);
+		} else {
+			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
+			MUSB_HST_MODE(musb);
+		}
+		if (!(devctl & MUSB_DEVCTL_SESSION) && !skip_session)
+			musb_writeb(musb->mregs,
+				    MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
+		mod_timer(&glue->timer, jiffies + POLL_SECONDS * HZ);
+		break;
+	case OTG_STATE_A_WAIT_VFALL:
+		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
+		break;
+	default:
+		break;
+	}
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+static void pic32_musb_try_idle(struct musb *musb, unsigned long timeout)
+{
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue = dev_get_drvdata(dev);
+
+	if (timeout == 0)
+		timeout = jiffies + msecs_to_jiffies(3);
+
+	/* Never idle if active, or when VBUS timeout is not set as host */
+	if (musb->is_active ||
+	    (musb->a_wait_bcon == 0 &&
+	     musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
+		dev_dbg(dev, "%s active, deleting timer\n",
+			usb_otg_state_string(musb->xceiv->otg->state));
+		del_timer(&glue->timer);
+		glue->last_timer = jiffies;
+		return;
+	}
+
+	if (musb->port_mode != MUSB_PORT_MODE_DUAL_ROLE)
+		return;
+
+	if (!musb->g.dev.driver)
+		return;
+
+	if (time_after(glue->last_timer, timeout) &&
+	    timer_pending(&glue->timer)) {
+		dev_dbg(dev, "Longer idle timer already pending, ignoring\n");
+		return;
+	}
+	glue->last_timer = timeout;
+
+	dev_dbg(dev, "%s inactive, starting idle timer for %u ms\n",
+		usb_otg_state_string(musb->xceiv->otg->state),
+		jiffies_to_msecs(timeout - jiffies));
+	mod_timer(&glue->timer, timeout);
+}
+
+static irqreturn_t pic32_musb_interrupt(int irq, void *hci)
+{
+	struct musb  *musb = hci;
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue;
+	unsigned long flags;
+	irqreturn_t ret = IRQ_NONE;
+
+	glue = dev_get_drvdata(dev->parent);
+	spin_lock_irqsave(&musb->lock, flags);
+
+	/* Get endpoint interrupts */
+	musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX) & PIC32_RX_EP_MASK;
+	musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX) & PIC32_TX_EP_MASK;
+
+	/* Get usb core interrupts */
+	musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
+	if (!musb->int_usb && !(musb->int_rx || musb->int_tx)) {
+		dev_err(dev, "Got USB spurious interrupt !\n");
+		goto irq_done;
+	}
+
+	if (is_host_active(musb) && musb->int_usb & MUSB_INTR_BABBLE)
+		dev_err(dev, "CAUTION: Babble interrupt occurred!\n");
+
+	/* Drop spurious RX and TX if device is disconnected */
+	if (musb->int_usb & MUSB_INTR_DISCONNECT) {
+		musb->int_tx = 0;
+		musb->int_rx = 0;
+	}
+
+	if (musb->int_tx || musb->int_rx || musb->int_usb)
+		ret |= musb_interrupt(musb);
+
+irq_done:
+	/* Poll for ID change in OTG port mode */
+	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE &&
+	    musb->port_mode == MUSB_PORT_MODE_DUAL_ROLE)
+		mod_timer(&glue->timer, jiffies + POLL_SECONDS * HZ);
+
+	spin_unlock_irqrestore(&musb->lock, flags);
+
+	return ret;
+}
+
+static int pic32_musb_set_mode(struct musb *musb, u8 mode)
+{
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue;
+	u32 crcon;
+
+	glue = dev_get_drvdata(dev->parent);
+	crcon = musb_readl(glue->cru, USBCRCON);
+	switch (mode) {
+	case MUSB_HOST:
+		crcon &= ~USBCRCON_USBIDVAL;
+		crcon |= USBCRCON_USBIDOVEN;
+		musb_writel(glue->cru, USBCRCON, crcon);
+		dev_dbg(dev, "MUSB Host mode enabled\n");
+		break;
+
+	case MUSB_PERIPHERAL:
+		crcon |= USBCRCON_USBIDVAL;
+		crcon |= USBCRCON_USBIDOVEN;
+		musb_writel(glue->cru, USBCRCON, crcon);
+		dev_dbg(dev, "MUSB Device mode enabled\n");
+		break;
+
+	case MUSB_OTG:
+		/* enable OTG mode using usb_id irq */
+		dev_warn(dev, "MUSB OTG mode enabled\n");
+		break;
+
+	default:
+		dev_err(dev, "unsupported mode %d\n", mode);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pic32_musb_init(struct musb *musb)
+{
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue;
+	u16 hwvers;
+	int ret;
+
+	glue = dev_get_drvdata(dev->parent);
+
+	/* Returns zero if e.g. not clocked */
+	hwvers = musb_read_hwvers(musb->mregs);
+	if (!hwvers)
+		return -ENODEV;
+
+	/* The PHY transceiver is registered using device tree */
+	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
+	if (IS_ERR_OR_NULL(musb->xceiv))
+		return -EPROBE_DEFER;
+
+	setup_timer(&glue->timer, otg_timer, (unsigned long)musb);
+
+	/* On-chip PHY and PLL is enabled by default */
+	musb->isr = pic32_musb_interrupt;
+
+	/* Request other interrupts */
+	irq_set_status_flags(glue->oc_irq, IRQ_NOAUTOEN);
+	ret = devm_request_irq(dev, glue->oc_irq, pic32_over_current,
+			       0, dev_name(dev), dev);
+	if (ret) {
+		dev_err(dev, "failed to request irq: %d\n", ret);
+		return ret;
+	}
+
+	switch (musb->port_mode) {
+	case MUSB_PORT_MODE_DUAL_ROLE:
+	case MUSB_PORT_MODE_HOST:
+	case MUSB_PORT_MODE_GADGET:
+		break;
+	default:
+		dev_err(dev, "unsupported mode %d\n", musb->port_mode);
+		return -EINVAL;
+	}
+
+	musb_writel(glue->cru, USBCRCON,
+		    USBCRCON_USBIDOVEN | USBCRCON_PHYIDEN |
+		    USBCRCON_USBIE | USBCRCON_USBRIE |
+		    USBCRCON_USBWKUPEN | USBCRCON_VBUSMONEN);
+
+	/* soft reset */
+	musb_writeb(musb->mregs, MUSB_SOFTRST, MUSB_SOFTRST_NRSTX);
+
+	return 0;
+}
+
+static int pic32_musb_exit(struct musb *musb)
+{
+	struct device *dev = musb->controller;
+	struct pic32_musb *glue;
+
+	glue = dev_get_drvdata(dev->parent);
+	del_timer_sync(&glue->timer);
+	/* no way to shutdown on-chip PHY and its PLL */
+	usb_put_phy(musb->xceiv);
+
+	return 0;
+}
+
+/* PIC32 supports only 32bit read operation */
+static void pic32_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
+{
+	void __iomem *fifo = hw_ep->fifo;
+	u32 val, rem = len % 4;
+
+	/* USB stack ensures dst is always 32bit aligned. */
+	readsl(fifo, dst, len / 4);
+
+	if (rem) {
+		dst += len & ~0x03;
+		val = musb_readl(fifo, 0);
+		memcpy(dst, &val, rem);
+	}
+}
+
+static const struct musb_platform_ops pic32_musb_ops = {
+	.quirks         = MUSB_DMA_INVENTRA | MUSB_INDEXED_EP,
+	.init		= pic32_musb_init,
+	.exit		= pic32_musb_exit,
+	.read_fifo	= pic32_read_fifo,
+#ifdef CONFIG_USB_INVENTRA_DMA
+	.dma_init	= musbhs_dma_controller_create,
+	.dma_exit	= musbhs_dma_controller_destroy,
+#endif
+	.enable		= pic32_musb_enable,
+	.disable	= pic32_musb_disable,
+	.set_mode	= pic32_musb_set_mode,
+	.try_idle	= pic32_musb_try_idle,
+	.set_vbus	= pic32_musb_set_vbus,
+};
+
+static u64 musb_dmamask = DMA_BIT_MASK(32);
+
+static int get_musb_port_mode(struct device *dev)
+{
+	enum usb_dr_mode mode;
+
+	mode = usb_get_dr_mode(dev);
+	switch (mode) {
+	case USB_DR_MODE_HOST:
+		return MUSB_PORT_MODE_HOST;
+	case USB_DR_MODE_PERIPHERAL:
+		return MUSB_PORT_MODE_GADGET;
+	case USB_DR_MODE_UNKNOWN:
+	case USB_DR_MODE_OTG:
+	default:
+		return MUSB_PORT_MODE_DUAL_ROLE;
+	}
+}
+
+/* Microchip FIFO config 0 - fits in 8KB */
+static struct musb_fifo_cfg pic32_musb_fifo_cfg0[] = {
+	{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 2, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 3, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 3, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 4, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 4, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 5, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 5, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 6, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 6, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 7, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 7, .style = FIFO_RX, .maxpacket = 512, },
+};
+
+/* Microchip FIFO config 1 - fits in 8KB */
+static struct musb_fifo_cfg pic32_musb_fifo_cfg1[] = {
+	{ .hw_ep_num = 1, .style = FIFO_TX,   .maxpacket = 512, },
+	{ .hw_ep_num = 1, .style = FIFO_RX,   .maxpacket = 512, },
+	{ .hw_ep_num = 2, .style = FIFO_TX,   .maxpacket = 512, },
+	{ .hw_ep_num = 2, .style = FIFO_RX,   .maxpacket = 512, },
+	{ .hw_ep_num = 3, .style = FIFO_TX,   .maxpacket = 512, },
+	{ .hw_ep_num = 3, .style = FIFO_RX,   .maxpacket = 512, },
+	{ .hw_ep_num = 4, .style = FIFO_RXTX, .maxpacket = 4096, },
+};
+
+static int pic32_probe_musb_device(struct pic32_musb *glue,
+				   struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct musb_hdrc_platform_data pdata;
+	struct musb_hdrc_config	*mconfig;
+	struct platform_device *platdev;
+	struct resource	resources[3];
+	struct resource	*res;
+	int fifo_mode = 0;
+	int ret;
+
+	memset(resources, 0, sizeof(resources));
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mc");
+	if (!res) {
+		dev_err(&pdev->dev, "failed to get memory.\n");
+		return -EINVAL;
+	}
+	resources[0] = *res;
+	resources[0].name = "mc";
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "mc");
+	if (!res) {
+		dev_err(&pdev->dev, "failed to get irq.\n");
+		return -EINVAL;
+	}
+	resources[1] = *res;
+	resources[1].name = "mc";
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "dma");
+	if (!res) {
+		dev_warn(&pdev->dev, "No MUSB DMA irq provided. Assuming PIO mode.\n");
+	} else {
+		resources[2] = *res;
+		resources[2].name = "dma";
+	}
+
+	/* allocate child platform device for musb platform driver */
+	platdev = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
+	if (!platdev)
+		return -ENOMEM;
+
+	glue->platdev = platdev;
+
+	platdev->dev.parent = &pdev->dev;
+	platdev->dev.dma_mask = &musb_dmamask;
+	platdev->dev.coherent_dma_mask = 0;
+
+	ret = platform_device_add_resources(platdev, resources,
+					    ARRAY_SIZE(resources));
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add resources\n");
+		goto err_pdev;
+	}
+
+	mconfig = devm_kzalloc(&pdev->dev, sizeof(*mconfig), GFP_KERNEL);
+	if (!mconfig) {
+		ret = -ENOMEM;
+		goto err_pdev;
+	}
+
+	mconfig->host_port_deassert_reset_at_resume = 1;
+	mconfig->multipoint = of_property_read_bool(np, "mentor,multipoint");
+	of_property_read_u32(np, "mentor,num-eps", (u32 *)&mconfig->num_eps);
+	of_property_read_u32(np, "mentor,ram-bits", (u32 *)&mconfig->ram_bits);
+
+	/* FiFo configuration */
+	of_property_read_u32(np, "microchip,fifo-mode", (u32 *)&fifo_mode);
+	dev_info(&pdev->dev, "using fifo mode %d\n", fifo_mode);
+	switch (fifo_mode) {
+	case 1:
+		mconfig->fifo_cfg = pic32_musb_fifo_cfg1;
+		mconfig->fifo_cfg_size = ARRAY_SIZE(pic32_musb_fifo_cfg1);
+		break;
+	default:
+		mconfig->fifo_cfg = pic32_musb_fifo_cfg0;
+		mconfig->fifo_cfg_size = ARRAY_SIZE(pic32_musb_fifo_cfg0);
+		break;
+	}
+
+	/* add platform data */
+	pdata.config = mconfig;
+	pdata.platform_ops = &pic32_musb_ops;
+	pdata.mode = get_musb_port_mode(&pdev->dev);
+
+	/* DT keeps this entry in mA, but musb expects it as per USB spec */
+	of_property_read_u32(np, "mentor,power", (u32 *)&pdata.power);
+	pdata.power /= 2;
+
+	ret = platform_device_add_data(platdev, &pdata, sizeof(pdata));
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add platform_data\n");
+		goto err_pdev;
+	}
+
+	ret = platform_device_add(platdev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register musb device\n");
+		goto err_pdev;
+	}
+
+	return 0;
+
+err_pdev:
+	platform_device_put(platdev);
+	return ret;
+}
+
+static int pic32_musb_probe(struct platform_device *pdev)
+{
+	struct device_node *dev_oc;
+	struct pic32_musb *glue;
+	struct resource	*cru;
+	int ret;
+
+	/* allocate glue */
+	glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
+	if (!glue)
+		return -ENOMEM;
+
+	dev_oc = of_parse_phandle(pdev->dev.of_node, "usb_overcurrent", 0);
+	if (!dev_oc) {
+		dev_err(&pdev->dev, "error usb_overcurrent property missing\n");
+		return -EINVAL;
+	}
+
+	glue->oc_irq = irq_of_parse_and_map(dev_oc, 0);
+	if (!glue->oc_irq) {
+		dev_err(&pdev->dev, "cannot get over current irq!\n");
+		ret = -EINVAL;
+		goto err_put_oc;
+	}
+
+	/* clock-reset module */
+	cru = platform_get_resource_byname(pdev, IORESOURCE_MEM, "usbcr");
+	glue->cru = devm_ioremap_resource(&pdev->dev, cru);
+	if (IS_ERR(glue->cru)) {
+		ret = PTR_ERR(glue->cru);
+		goto err_put_oc;
+	}
+
+	glue->clk = devm_clk_get(&pdev->dev, "usb_clk");
+	if (IS_ERR(glue->clk)) {
+		dev_err(&pdev->dev, "failed to get usb_clk %d\n", ret);
+		ret = PTR_ERR(glue->clk);
+		goto err_put_oc;
+	}
+
+	ret = clk_prepare_enable(glue->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable usb_clk %d\n", ret);
+		goto err_put_oc;
+	}
+
+	platform_set_drvdata(pdev, glue);
+
+	ret = pic32_probe_musb_device(glue, pdev);
+	if (ret) {
+		clk_disable_unprepare(glue->clk);
+		goto err_put_oc;
+	}
+
+err_put_oc:
+	of_node_put(dev_oc);
+	return ret;
+}
+
+static int pic32_remove(struct platform_device *pdev)
+{
+	struct pic32_musb *glue = platform_get_drvdata(pdev);
+
+	platform_device_unregister(glue->platdev);
+	clk_disable_unprepare(glue->clk);
+
+	return 0;
+}
+
+static const struct of_device_id pic32_musb_of_match[] = {
+	{ .compatible = "microchip,pic32mzda-usb" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pic32_musb_of_match);
+
+static struct platform_driver pic32_musb_driver = {
+	.probe	= pic32_musb_probe,
+	.remove	= pic32_remove,
+	.driver	= {
+		.name		= "musb-pic32mz",
+		.of_match_table	= pic32_musb_of_match,
+	},
+};
+
+MODULE_DESCRIPTION("Microchip PIC32 MUSB Glue Layer");
+MODULE_AUTHOR("Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+
+module_platform_driver(pic32_musb_driver);
-- 
1.8.3.1