USB: gadget: MIPS ci13xxx_udc

MIPS USB IP core family device controller
Currently it only supports IP part number CI13412.

[dbrownell@users.sourceforge.net: minor comment tweaks]

Signed-off-by: David Lopo <dlopo@chipidea.mips.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 3051 insertions, 0 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index dd4cd5a5137..cf3a662c333 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -377,6 +377,24 @@ config USB_FSL_QE
 	default USB_GADGET
 	select USB_GADGET_SELECTED
 
+config USB_GADGET_CI13XXX
+	boolean "MIPS USB CI13xxx"
+	depends on PCI
+	select USB_GADGET_DUALSPEED
+	help
+	  MIPS USB IP core family device controller
+	  Currently it only supports IP part number CI13412
+
+	  Say "y" to link the driver statically, or "m" to build a
+	  dynamically linked module called "ci13xxx_udc" and force all
+	  gadget drivers to also be dynamically linked.
+
+config USB_CI13XXX
+	tristate
+	depends on USB_GADGET_CI13XXX
+	default USB_GADGET
+	select USB_GADGET_SELECTED
+
 config USB_GADGET_NET2280
 	boolean "NetChip 228x"
 	depends on PCI
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index bd4041b47dc..5d64a2ab188 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_USB_ATMEL_USBA)	+= atmel_usba_udc.o
 obj-$(CONFIG_USB_FSL_USB2)	+= fsl_usb2_udc.o
 obj-$(CONFIG_USB_M66592)	+= m66592-udc.o
 obj-$(CONFIG_USB_FSL_QE)	+= fsl_qe_udc.o
+obj-$(CONFIG_USB_CI13XXX)	+= ci13xxx_udc.o
 
 #
 # USB gadget drivers
diff --git a/drivers/usb/gadget/ci13xxx_udc.c b/drivers/usb/gadget/ci13xxx_udc.c
new file mode 100644
index 00000000000..bebf911c7e5
--- /dev/null
+++ b/drivers/usb/gadget/ci13xxx_udc.c
@@ -0,0 +1,2830 @@
+/*
+ * ci13xxx_udc.c - MIPS USB IP core family device controller
+ *
+ * Copyright (C) 2008 Chipidea - MIPS Technologies, Inc. All rights reserved.
+ *
+ * Author: David Lopo
+ *
+ * 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.
+ */
+
+/*
+ * Description: MIPS USB IP core family device controller
+ *              Currently it only supports IP part number CI13412
+ *
+ * This driver is composed of several blocks:
+ * - HW:     hardware interface
+ * - DBG:    debug facilities (optional)
+ * - UTIL:   utilities
+ * - ISR:    interrupts handling
+ * - ENDPT:  endpoint operations (Gadget API)
+ * - GADGET: gadget operations (Gadget API)
+ * - BUS:    bus glue code, bus abstraction layer
+ * - PCI:    PCI core interface and PCI resources (interrupts, memory...)
+ *
+ * Compile Options
+ * - CONFIG_USB_GADGET_DEBUG_FILES: enable debug facilities
+ * - STALL_IN:  non-empty bulk-in pipes cannot be halted
+ *              if defined mass storage compliance succeeds but with warnings
+ *              => case 4: Hi >  Dn
+ *              => case 5: Hi >  Di
+ *              => case 8: Hi <> Do
+ *              if undefined usbtest 13 fails
+ * - TRACE:     enable function tracing (depends on DEBUG)
+ *
+ * Main Features
+ * - Chapter 9 & Mass Storage Compliance with Gadget File Storage
+ * - Chapter 9 Compliance with Gadget Zero (STALL_IN undefined)
+ * - Normal & LPM support
+ *
+ * USBTEST Report
+ * - OK: 0-12, 13 (STALL_IN defined) & 14
+ * - Not Supported: 15 & 16 (ISO)
+ *
+ * TODO List
+ * - OTG
+ * - Isochronous & Interrupt Traffic
+ * - Handle requests which spawns into several TDs
+ * - GET_STATUS(device) - always reports 0
+ * - Gadget API (majority of optional features)
+ * - Suspend & Remote Wakeup
+ */
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+
+#include "ci13xxx_udc.h"
+
+
+/******************************************************************************
+ * DEFINE
+ *****************************************************************************/
+/* ctrl register bank access */
+static DEFINE_SPINLOCK(udc_lock);
+
+/* driver name */
+#define UDC_DRIVER_NAME   "ci13xxx_udc"
+
+/* control endpoint description */
+static const struct usb_endpoint_descriptor
+ctrl_endpt_desc = {
+	.bLength         = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+
+	.bmAttributes    = USB_ENDPOINT_XFER_CONTROL,
+	.wMaxPacketSize  = cpu_to_le16(CTRL_PAYLOAD_MAX),
+};
+
+/* UDC descriptor */
+static struct ci13xxx *_udc;
+
+/* Interrupt statistics */
+#define ISR_MASK   0x1F
+static struct {
+	u32 test;
+	u32 ui;
+	u32 uei;
+	u32 pci;
+	u32 uri;
+	u32 sli;
+	u32 none;
+	struct {
+		u32 cnt;
+		u32 buf[ISR_MASK+1];
+		u32 idx;
+	} hndl;
+} isr_statistics;
+
+/**
+ * ffs_nr: find first (least significant) bit set
+ * @x: the word to search
+ *
+ * This function returns bit number (instead of position)
+ */
+static int ffs_nr(u32 x)
+{
+	int n = ffs(x);
+
+	return n ? n-1 : 32;
+}
+
+/******************************************************************************
+ * HW block
+ *****************************************************************************/
+/* register bank descriptor */
+static struct {
+	unsigned      lpm;    /* is LPM? */
+	void __iomem *abs;    /* bus map offset */
+	void __iomem *cap;    /* bus map offset + CAP offset + CAP data */
+	size_t        size;   /* bank size */
+} hw_bank;
+
+/* UDC register map */
+#define ABS_CAPLENGTH       (0x100UL)
+#define ABS_HCCPARAMS       (0x108UL)
+#define ABS_DCCPARAMS       (0x124UL)
+#define ABS_TESTMODE        (hw_bank.lpm ? 0x0FCUL : 0x138UL)
+/* offset to CAPLENTGH (addr + data) */
+#define CAP_USBCMD          (0x000UL)
+#define CAP_USBSTS          (0x004UL)
+#define CAP_USBINTR         (0x008UL)
+#define CAP_DEVICEADDR      (0x014UL)
+#define CAP_ENDPTLISTADDR   (0x018UL)
+#define CAP_PORTSC          (0x044UL)
+#define CAP_DEVLC           (0x0B4UL)
+#define CAP_USBMODE         (hw_bank.lpm ? 0x0C8UL : 0x068UL)
+#define CAP_ENDPTSETUPSTAT  (hw_bank.lpm ? 0x0D8UL : 0x06CUL)
+#define CAP_ENDPTPRIME      (hw_bank.lpm ? 0x0DCUL : 0x070UL)
+#define CAP_ENDPTFLUSH      (hw_bank.lpm ? 0x0E0UL : 0x074UL)
+#define CAP_ENDPTSTAT       (hw_bank.lpm ? 0x0E4UL : 0x078UL)
+#define CAP_ENDPTCOMPLETE   (hw_bank.lpm ? 0x0E8UL : 0x07CUL)
+#define CAP_ENDPTCTRL       (hw_bank.lpm ? 0x0ECUL : 0x080UL)
+#define CAP_LAST            (hw_bank.lpm ? 0x12CUL : 0x0C0UL)
+
+/* maximum number of enpoints: valid only after hw_device_reset() */
+static unsigned hw_ep_max;
+
+/**
+ * hw_ep_bit: calculates the bit number
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns bit number
+ */
+static inline int hw_ep_bit(int num, int dir)
+{
+	return num + (dir ? 16 : 0);
+}
+
+/**
+ * hw_aread: reads from register bitfield
+ * @addr: address relative to bus map
+ * @mask: bitfield mask
+ *
+ * This function returns register bitfield data
+ */
+static u32 hw_aread(u32 addr, u32 mask)
+{
+	return ioread32(addr + hw_bank.abs) & mask;
+}
+
+/**
+ * hw_awrite: writes to register bitfield
+ * @addr: address relative to bus map
+ * @mask: bitfield mask
+ * @data: new data
+ */
+static void hw_awrite(u32 addr, u32 mask, u32 data)
+{
+	iowrite32(hw_aread(addr, ~mask) | (data & mask),
+		  addr + hw_bank.abs);
+}
+
+/**
+ * hw_cread: reads from register bitfield
+ * @addr: address relative to CAP offset plus content
+ * @mask: bitfield mask
+ *
+ * This function returns register bitfield data
+ */
+static u32 hw_cread(u32 addr, u32 mask)
+{
+	return ioread32(addr + hw_bank.cap) & mask;
+}
+
+/**
+ * hw_cwrite: writes to register bitfield
+ * @addr: address relative to CAP offset plus content
+ * @mask: bitfield mask
+ * @data: new data
+ */
+static void hw_cwrite(u32 addr, u32 mask, u32 data)
+{
+	iowrite32(hw_cread(addr, ~mask) | (data & mask),
+		  addr + hw_bank.cap);
+}
+
+/**
+ * hw_ctest_and_clear: tests & clears register bitfield
+ * @addr: address relative to CAP offset plus content
+ * @mask: bitfield mask
+ *
+ * This function returns register bitfield data
+ */
+static u32 hw_ctest_and_clear(u32 addr, u32 mask)
+{
+	u32 reg = hw_cread(addr, mask);
+
+	iowrite32(reg, addr + hw_bank.cap);
+	return reg;
+}
+
+/**
+ * hw_ctest_and_write: tests & writes register bitfield
+ * @addr: address relative to CAP offset plus content
+ * @mask: bitfield mask
+ * @data: new data
+ *
+ * This function returns register bitfield data
+ */
+static u32 hw_ctest_and_write(u32 addr, u32 mask, u32 data)
+{
+	u32 reg = hw_cread(addr, ~0);
+
+	iowrite32((reg & ~mask) | (data & mask), addr + hw_bank.cap);
+	return (reg & mask) >> ffs_nr(mask);
+}
+
+/**
+ * hw_device_reset: resets chip (execute without interruption)
+ * @base: register base address
+ *
+ * This function returns an error code
+ */
+static int hw_device_reset(void __iomem *base)
+{
+	u32 reg;
+
+	/* bank is a module variable */
+	hw_bank.abs = base;
+
+	hw_bank.cap = hw_bank.abs;
+	hw_bank.cap += ABS_CAPLENGTH;
+	hw_bank.cap += ioread8(hw_bank.cap);
+
+	reg = hw_aread(ABS_HCCPARAMS, HCCPARAMS_LEN) >> ffs_nr(HCCPARAMS_LEN);
+	hw_bank.lpm  = reg;
+	hw_bank.size = hw_bank.cap - hw_bank.abs;
+	hw_bank.size += CAP_LAST;
+	hw_bank.size /= sizeof(u32);
+
+	/* should flush & stop before reset */
+	hw_cwrite(CAP_ENDPTFLUSH, ~0, ~0);
+	hw_cwrite(CAP_USBCMD, USBCMD_RS, 0);
+
+	hw_cwrite(CAP_USBCMD, USBCMD_RST, USBCMD_RST);
+	while (hw_cread(CAP_USBCMD, USBCMD_RST))
+		udelay(10);             /* not RTOS friendly */
+
+	/* USBMODE should be configured step by step */
+	hw_cwrite(CAP_USBMODE, USBMODE_CM, USBMODE_CM_IDLE);
+	hw_cwrite(CAP_USBMODE, USBMODE_CM, USBMODE_CM_DEVICE);
+	hw_cwrite(CAP_USBMODE, USBMODE_SLOM, USBMODE_SLOM);  /* HW >= 2.3 */
+
+	if (hw_cread(CAP_USBMODE, USBMODE_CM) != USBMODE_CM_DEVICE) {
+		pr_err("cannot enter in device mode");
+		pr_err("lpm = %i", hw_bank.lpm);
+		return -ENODEV;
+	}
+
+	reg = hw_aread(ABS_DCCPARAMS, DCCPARAMS_DEN) >> ffs_nr(DCCPARAMS_DEN);
+	if (reg == 0 || reg > ENDPT_MAX)
+		return -ENODEV;
+
+	hw_ep_max = reg;   /* cache hw ENDPT_MAX */
+
+	/* setup lock mode ? */
+
+	/* ENDPTSETUPSTAT is '0' by default */
+
+	/* HCSPARAMS.bf.ppc SHOULD BE zero for device */
+
+	return 0;
+}
+
+/**
+ * hw_device_state: enables/disables interrupts & starts/stops device (execute
+ *                  without interruption)
+ * @dma: 0 => disable, !0 => enable and set dma engine
+ *
+ * This function returns an error code
+ */
+static int hw_device_state(u32 dma)
+{
+	if (dma) {
+		hw_cwrite(CAP_ENDPTLISTADDR, ~0, dma);
+		/* interrupt, error, port change, reset, sleep/suspend */
+		hw_cwrite(CAP_USBINTR, ~0,
+			     USBi_UI|USBi_UEI|USBi_PCI|USBi_URI|USBi_SLI);
+		hw_cwrite(CAP_USBCMD, USBCMD_RS, USBCMD_RS);
+	} else {
+		hw_cwrite(CAP_USBCMD, USBCMD_RS, 0);
+		hw_cwrite(CAP_USBINTR, ~0, 0);
+	}
+	return 0;
+}
+
+/**
+ * hw_ep_flush: flush endpoint fifo (execute without interruption)
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns an error code
+ */
+static int hw_ep_flush(int num, int dir)
+{
+	int n = hw_ep_bit(num, dir);
+
+	do {
+		/* flush any pending transfer */
+		hw_cwrite(CAP_ENDPTFLUSH, BIT(n), BIT(n));
+		while (hw_cread(CAP_ENDPTFLUSH, BIT(n)))
+			cpu_relax();
+	} while (hw_cread(CAP_ENDPTSTAT, BIT(n)));
+
+	return 0;
+}
+
+/**
+ * hw_ep_disable: disables endpoint (execute without interruption)
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns an error code
+ */
+static int hw_ep_disable(int num, int dir)
+{
+	hw_ep_flush(num, dir);
+	hw_cwrite(CAP_ENDPTCTRL + num * sizeof(u32),
+		  dir ? ENDPTCTRL_TXE : ENDPTCTRL_RXE, 0);
+	return 0;
+}
+
+/**
+ * hw_ep_enable: enables endpoint (execute without interruption)
+ * @num:  endpoint number
+ * @dir:  endpoint direction
+ * @type: endpoint type
+ *
+ * This function returns an error code
+ */
+static int hw_ep_enable(int num, int dir, int type)
+{
+	u32 mask, data;
+
+	if (dir) {
+		mask  = ENDPTCTRL_TXT;  /* type    */
+		data  = type << ffs_nr(mask);
+
+		mask |= ENDPTCTRL_TXS;  /* unstall */
+		mask |= ENDPTCTRL_TXR;  /* reset data toggle */
+		data |= ENDPTCTRL_TXR;
+		mask |= ENDPTCTRL_TXE;  /* enable  */
+		data |= ENDPTCTRL_TXE;
+	} else {
+		mask  = ENDPTCTRL_RXT;  /* type    */
+		data  = type << ffs_nr(mask);
+
+		mask |= ENDPTCTRL_RXS;  /* unstall */
+		mask |= ENDPTCTRL_RXR;  /* reset data toggle */
+		data |= ENDPTCTRL_RXR;
+		mask |= ENDPTCTRL_RXE;  /* enable  */
+		data |= ENDPTCTRL_RXE;
+	}
+	hw_cwrite(CAP_ENDPTCTRL + num * sizeof(u32), mask, data);
+	return 0;
+}
+
+/**
+ * hw_ep_get_halt: return endpoint halt status
+ * @num: endpoint number
+ * @dir: endpoint direction
+ *
+ * This function returns 1 if endpoint halted
+ */
+static int hw_ep_get_halt(int num, int dir)
+{
+	u32 mask = dir ? ENDPTCTRL_TXS : ENDPTCTRL_RXS;
+
+	return hw_cread(CAP_ENDPTCTRL + num * sizeof(u32), mask) ? 1 : 0;
+}
+
+/**
+ * hw_ep_is_primed: test if endpoint is primed (execute without interruption)
+ * @num:   endpoint number
+ * @dir:   endpoint direction
+ *
+ * This function returns true if endpoint primed
+ */
+static int hw_ep_is_primed(int num, int dir)
+{
+	u32 reg = hw_cread(CAP_ENDPTPRIME, ~0) | hw_cread(CAP_ENDPTSTAT, ~0);
+
+	return test_bit(hw_ep_bit(num, dir), (void *)&reg);
+}
+
+/**
+ * hw_test_and_clear_setup_status: test & clear setup status (execute without
+ *                                 interruption)
+ * @n: bit number (endpoint)
+ *
+ * This function returns setup status
+ */
+static int hw_test_and_clear_setup_status(int n)
+{
+	return hw_ctest_and_clear(CAP_ENDPTSETUPSTAT, BIT(n));
+}
+
+/**
+ * hw_ep_prime: primes endpoint (execute without interruption)
+ * @num:     endpoint number
+ * @dir:     endpoint direction
+ * @is_ctrl: true if control endpoint
+ *
+ * This function returns an error code
+ */
+static int hw_ep_prime(int num, int dir, int is_ctrl)
+{
+	int n = hw_ep_bit(num, dir);
+
+	/* the caller should flush first */
+	if (hw_ep_is_primed(num, dir))
+		return -EBUSY;
+
+	if (is_ctrl && dir == RX && hw_cread(CAP_ENDPTSETUPSTAT, BIT(num)))
+		return -EAGAIN;
+
+	hw_cwrite(CAP_ENDPTPRIME, BIT(n), BIT(n));
+
+	while (hw_cread(CAP_ENDPTPRIME, BIT(n)))
+		cpu_relax();
+	if (is_ctrl && dir == RX  && hw_cread(CAP_ENDPTSETUPSTAT, BIT(num)))
+		return -EAGAIN;
+
+	/* status shoult be tested according with manual but it doesn't work */
+	return 0;
+}
+
+/**
+ * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute
+ *                 without interruption)
+ * @num:   endpoint number
+ * @dir:   endpoint direction
+ * @value: true => stall, false => unstall
+ *
+ * This function returns an error code
+ */
+static int hw_ep_set_halt(int num, int dir, int value)
+{
+	if (value != 0 && value != 1)
+		return -EINVAL;
+
+	do {
+		u32 addr = CAP_ENDPTCTRL + num * sizeof(u32);
+		u32 mask_xs = dir ? ENDPTCTRL_TXS : ENDPTCTRL_RXS;
+		u32 mask_xr = dir ? ENDPTCTRL_TXR : ENDPTCTRL_RXR;
+
+		/* data toggle - reserved for EP0 but it's in ESS */
+		hw_cwrite(addr, mask_xs|mask_xr, value ? mask_xs : mask_xr);
+
+	} while (value != hw_ep_get_halt(num, dir));
+
+	return 0;
+}
+
+/**
+ * hw_intr_clear: disables interrupt & clears interrupt status (execute without
+ *                interruption)
+ * @n: interrupt bit
+ *
+ * This function returns an error code
+ */
+static int hw_intr_clear(int n)
+{
+	if (n >= REG_BITS)
+		return -EINVAL;
+
+	hw_cwrite(CAP_USBINTR, BIT(n), 0);
+	hw_cwrite(CAP_USBSTS,  BIT(n), BIT(n));
+	return 0;
+}
+
+/**
+ * hw_intr_force: enables interrupt & forces interrupt status (execute without
+ *                interruption)
+ * @n: interrupt bit
+ *
+ * This function returns an error code
+ */
+static int hw_intr_force(int n)
+{
+	if (n >= REG_BITS)
+		return -EINVAL;
+
+	hw_awrite(ABS_TESTMODE, TESTMODE_FORCE, TESTMODE_FORCE);
+	hw_cwrite(CAP_USBINTR,  BIT(n), BIT(n));
+	hw_cwrite(CAP_USBSTS,   BIT(n), BIT(n));
+	hw_awrite(ABS_TESTMODE, TESTMODE_FORCE, 0);
+	return 0;
+}
+
+/**
+ * hw_is_port_high_speed: test if port is high speed
+ *
+ * This function returns true if high speed port
+ */
+static int hw_port_is_high_speed(void)
+{
+	return hw_bank.lpm ? hw_cread(CAP_DEVLC, DEVLC_PSPD) :
+		hw_cread(CAP_PORTSC, PORTSC_HSP);
+}
+
+/**
+ * hw_port_test_get: reads port test mode value
+ *
+ * This function returns port test mode value
+ */
+static u8 hw_port_test_get(void)
+{
+	return hw_cread(CAP_PORTSC, PORTSC_PTC) >> ffs_nr(PORTSC_PTC);
+}
+
+/**
+ * hw_port_test_set: writes port test mode (execute without interruption)
+ * @mode: new value
+ *
+ * This function returns an error code
+ */
+static int hw_port_test_set(u8 mode)
+{
+	const u8 TEST_MODE_MAX = 7;
+
+	if (mode > TEST_MODE_MAX)
+		return -EINVAL;
+
+	hw_cwrite(CAP_PORTSC, PORTSC_PTC, mode << ffs_nr(PORTSC_PTC));
+	return 0;
+}
+
+/**
+ * hw_read_intr_enable: returns interrupt enable register
+ *
+ * This function returns register data
+ */
+static u32 hw_read_intr_enable(void)
+{
+	return hw_cread(CAP_USBINTR, ~0);
+}
+
+/**
+ * hw_read_intr_status: returns interrupt status register
+ *
+ * This function returns register data
+ */
+static u32 hw_read_intr_status(void)
+{
+	return hw_cread(CAP_USBSTS, ~0);
+}
+
+/**
+ * hw_register_read: reads all device registers (execute without interruption)
+ * @buf:  destination buffer
+ * @size: buffer size
+ *
+ * This function returns number of registers read
+ */
+static size_t hw_register_read(u32 *buf, size_t size)
+{
+	unsigned i;
+
+	if (size > hw_bank.size)
+		size = hw_bank.size;
+
+	for (i = 0; i < size; i++)
+		buf[i] = hw_aread(i * sizeof(u32), ~0);
+
+	return size;
+}
+
+/**
+ * hw_register_write: writes to register
+ * @addr: register address
+ * @data: register value
+ *
+ * This function returns an error code
+ */
+static int hw_register_write(u16 addr, u32 data)
+{
+	/* align */
+	addr /= sizeof(u32);
+
+	if (addr >= hw_bank.size)
+		return -EINVAL;
+
+	/* align */
+	addr *= sizeof(u32);
+
+	hw_awrite(addr, ~0, data);
+	return 0;
+}
+
+/**
+ * hw_test_and_clear_complete: test & clear complete status (execute without
+ *                             interruption)
+ * @n: bit number (endpoint)
+ *
+ * This function returns complete status
+ */
+static int hw_test_and_clear_complete(int n)
+{
+	return hw_ctest_and_clear(CAP_ENDPTCOMPLETE, BIT(n));
+}
+
+/**
+ * hw_test_and_clear_intr_active: test & clear active interrupts (execute
+ *                                without interruption)
+ *
+ * This function returns active interrutps
+ */
+static u32 hw_test_and_clear_intr_active(void)
+{
+	u32 reg = hw_read_intr_status() & hw_read_intr_enable();
+
+	hw_cwrite(CAP_USBSTS, ~0, reg);
+	return reg;
+}
+
+/**
+ * hw_test_and_clear_setup_guard: test & clear setup guard (execute without
+ *                                interruption)
+ *
+ * This function returns guard value
+ */
+static int hw_test_and_clear_setup_guard(void)
+{
+	return hw_ctest_and_write(CAP_USBCMD, USBCMD_SUTW, 0);
+}
+
+/**
+ * hw_test_and_set_setup_guard: test & set setup guard (execute without
+ *                              interruption)
+ *
+ * This function returns guard value
+ */
+static int hw_test_and_set_setup_guard(void)
+{
+	return hw_ctest_and_write(CAP_USBCMD, USBCMD_SUTW, USBCMD_SUTW);
+}
+
+/**
+ * hw_usb_set_address: configures USB address (execute without interruption)
+ * @value: new USB address
+ *
+ * This function returns an error code
+ */
+static int hw_usb_set_address(u8 value)
+{
+	/* advance */
+	hw_cwrite(CAP_DEVICEADDR, DEVICEADDR_USBADR | DEVICEADDR_USBADRA,
+		  value << ffs_nr(DEVICEADDR_USBADR) | DEVICEADDR_USBADRA);
+	return 0;
+}
+
+/**
+ * hw_usb_reset: restart device after a bus reset (execute without
+ *               interruption)
+ *
+ * This function returns an error code
+ */
+static int hw_usb_reset(void)
+{
+	hw_usb_set_address(0);
+
+	/* ESS flushes only at end?!? */
+	hw_cwrite(CAP_ENDPTFLUSH,    ~0, ~0);   /* flush all EPs */
+
+	/* clear setup token semaphores */
+	hw_cwrite(CAP_ENDPTSETUPSTAT, 0,  0);   /* writes its content */
+
+	/* clear complete status */
+	hw_cwrite(CAP_ENDPTCOMPLETE,  0,  0);   /* writes its content */
+
+	/* wait until all bits cleared */
+	while (hw_cread(CAP_ENDPTPRIME, ~0))
+		udelay(10);             /* not RTOS friendly */
+
+	/* reset all endpoints ? */
+
+	/* reset internal status and wait for further instructions
+	   no need to verify the port reset status (ESS does it) */
+
+	return 0;
+}
+
+/******************************************************************************
+ * DBG block
+ *****************************************************************************/
+/**
+ * show_device: prints information about device capabilities and status
+ *
+ * Check "device.h" for details
+ */
+static ssize_t show_device(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct ci13xxx *udc = container_of(dev, struct ci13xxx, gadget.dev);
+	struct usb_gadget *gadget = &udc->gadget;
+	int n = 0;
+
+	dbg_trace("[%s] %p\n", __func__, buf);
+	if (attr == NULL || buf == NULL) {
+		dev_err(dev, "[%s] EINVAL\n", __func__);
+		return 0;
+	}
+
+	n += scnprintf(buf + n, PAGE_SIZE - n, "speed             = %d\n",
+		       gadget->speed);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "is_dualspeed      = %d\n",
+		       gadget->is_dualspeed);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "is_otg            = %d\n",
+		       gadget->is_otg);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "is_a_peripheral   = %d\n",
+		       gadget->is_a_peripheral);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "b_hnp_enable      = %d\n",
+		       gadget->b_hnp_enable);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "a_hnp_support     = %d\n",
+		       gadget->a_hnp_support);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "a_alt_hnp_support = %d\n",
+		       gadget->a_alt_hnp_support);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "name              = %s\n",
+		       (gadget->name ? gadget->name : ""));
+
+	return n;
+}
+static DEVICE_ATTR(device, S_IRUSR, show_device, NULL);
+
+/**
+ * show_driver: prints information about attached gadget (if any)
+ *
+ * Check "device.h" for details
+ */
+static ssize_t show_driver(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct ci13xxx *udc = container_of(dev, struct ci13xxx, gadget.dev);
+	struct usb_gadget_driver *driver = udc->driver;
+	int n = 0;
+
+	dbg_trace("[%s] %p\n", __func__, buf);
+	if (attr == NULL || buf == NULL) {
+		dev_err(dev, "[%s] EINVAL\n", __func__);
+		return 0;
+	}
+
+	if (driver == NULL)
+		return scnprintf(buf, PAGE_SIZE,
+				 "There is no gadget attached!\n");
+
+	n += scnprintf(buf + n, PAGE_SIZE - n, "function  = %s\n",
+		       (driver->function ? driver->function : ""));
+	n += scnprintf(buf + n, PAGE_SIZE - n, "max speed = %d\n",
+		       driver->speed);
+
+	return n;
+}
+static DEVICE_ATTR(driver, S_IRUSR, show_driver, NULL);
+
+/* Maximum event message length */
+#define DBG_DATA_MSG   64UL
+
+/* Maximum event messages */
+#define DBG_DATA_MAX   128UL
+
+/* Event buffer descriptor */
+static struct {
+	char     (buf[DBG_DATA_MAX])[DBG_DATA_MSG];   /* buffer */
+	unsigned idx;   /* index */
+	unsigned tty;   /* print to console? */
+	rwlock_t lck;   /* lock */
+} dbg_data = {
+	.idx = 0,
+	.tty = 0,
+	.lck = __RW_LOCK_UNLOCKED(lck)
+};
+
+/**
+ * dbg_dec: decrements debug event index
+ * @idx: buffer index
+ */
+static void dbg_dec(unsigned *idx)
+{
+	*idx = (*idx - 1) & (DBG_DATA_MAX-1);
+}
+
+/**
+ * dbg_inc: increments debug event index
+ * @idx: buffer index
+ */
+static void dbg_inc(unsigned *idx)
+{
+	*idx = (*idx + 1) & (DBG_DATA_MAX-1);
+}
+
+/**
+ * dbg_print:  prints the common part of the event
+ * @addr:   endpoint address
+ * @name:   event name
+ * @status: status
+ * @extra:  extra information
+ */
+static void dbg_print(u8 addr, const char *name, int status, const char *extra)
+{
+	struct timeval tval;
+	unsigned int stamp;
+	unsigned long flags;
+
+	write_lock_irqsave(&dbg_data.lck, flags);
+
+	do_gettimeofday(&tval);
+	stamp = tval.tv_sec & 0xFFFF;	/* 2^32 = 4294967296. Limit to 4096s */
+	stamp = stamp * 1000000 + tval.tv_usec;
+
+	scnprintf(dbg_data.buf[dbg_data.idx], DBG_DATA_MSG,
+		  "%04X\t» %02X %-7.7s %4i «\t%s\n",
+		  stamp, addr, name, status, extra);
+
+	dbg_inc(&dbg_data.idx);
+
+	write_unlock_irqrestore(&dbg_data.lck, flags);
+
+	if (dbg_data.tty != 0)
+		pr_notice("%04X\t» %02X %-7.7s %4i «\t%s\n",
+			  stamp, addr, name, status, extra);
+}
+
+/**
+ * dbg_done: prints a DONE event
+ * @addr:   endpoint address
+ * @td:     transfer descriptor
+ * @status: status
+ */
+static void dbg_done(u8 addr, const u32 token, int status)
+{
+	char msg[DBG_DATA_MSG];
+
+	scnprintf(msg, sizeof(msg), "%d %02X",
+		  (int)(token & TD_TOTAL_BYTES) >> ffs_nr(TD_TOTAL_BYTES),
+		  (int)(token & TD_STATUS)      >> ffs_nr(TD_STATUS));
+	dbg_print(addr, "DONE", status, msg);
+}
+
+/**
+ * dbg_event: prints a generic event
+ * @addr:   endpoint address
+ * @name:   event name
+ * @status: status
+ */
+static void dbg_event(u8 addr, const char *name, int status)
+{
+	if (name != NULL)
+		dbg_print(addr, name, status, "");
+}
+
+/*
+ * dbg_queue: prints a QUEUE event
+ * @addr:   endpoint address
+ * @req:    USB request
+ * @status: status
+ */
+static void dbg_queue(u8 addr, const struct usb_request *req, int status)
+{
+	char msg[DBG_DATA_MSG];
+
+	if (req != NULL) {
+		scnprintf(msg, sizeof(msg),
+			  "%d %d", !req->no_interrupt, req->length);
+		dbg_print(addr, "QUEUE", status, msg);
+	}
+}
+
+/**
+ * dbg_setup: prints a SETUP event
+ * @addr: endpoint address
+ * @req:  setup request
+ */
+static void dbg_setup(u8 addr, const struct usb_ctrlrequest *req)
+{
+	char msg[DBG_DATA_MSG];
+
+	if (req != NULL) {
+		scnprintf(msg, sizeof(msg),
+			  "%02X %02X %04X %04X %d", req->bRequestType,
+			  req->bRequest, le16_to_cpu(req->wValue),
+			  le16_to_cpu(req->wIndex), le16_to_cpu(req->wLength));
+		dbg_print(addr, "SETUP", 0, msg);
+	}
+}
+
+/**
+ * show_events: displays the event buffer
+ *
+ * Check "device.h" for details
+ */
+static ssize_t show_events(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	unsigned long flags;
+	unsigned i, j, n = 0;
+
+	dbg_trace("[%s] %p\n", __func__, buf);
+	if (attr == NULL || buf == NULL) {
+		dev_err(dev, "[%s] EINVAL\n", __func__);
+		return 0;
+	}
+
+	read_lock_irqsave(&dbg_data.lck, flags);
+
+	i = dbg_data.idx;
+	for (dbg_dec(&i); i != dbg_data.idx; dbg_dec(&i)) {
+		n += strlen(dbg_data.buf[i]);
+		if (n >= PAGE_SIZE) {
+			n -= strlen(dbg_data.buf[i]);
+			break;
+		}
+	}
+	for (j = 0, dbg_inc(&i); j < n; dbg_inc(&i))
+		j += scnprintf(buf + j, PAGE_SIZE - j,
+			       "%s", dbg_data.buf[i]);
+
+	read_unlock_irqrestore(&dbg_data.lck, flags);
+
+	return n;
+}
+
+/**
+ * store_events: configure if events are going to be also printed to console
+ *
+ * Check "device.h" for details
+ */
+static ssize_t store_events(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	unsigned tty;
+
+	dbg_trace("[%s] %p, %d\n", __func__, buf, count);
+	if (attr == NULL || buf == NULL) {
+		dev_err(dev, "[%s] EINVAL\n", __func__);
+		goto done;
+	}
+
+	if (sscanf(buf, "%u", &tty) != 1 || tty > 1) {
+		dev_err(dev, "<1|0>: enable|disable console log\n");
+		goto done;
+	}
+
+	dbg_data.tty = tty;
+	dev_info(dev, "tty = %u", dbg_data.tty);
+
+ done:
+	return count;
+}
+static DEVICE_ATTR(events, S_IRUSR | S_IWUSR, show_events, store_events);
+
+/**
+ * show_inters: interrupt status, enable status and historic
+ *
+ * Check "device.h" for details
+ */
+static ssize_t show_inters(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct ci13xxx *udc = container_of(dev, struct ci13xxx, gadget.dev);
+	unsigned long flags;
+	u32 intr;
+	unsigned i, j, n = 0;
+
+	dbg_trace("[%s] %p\n", __func__, buf);
+	if (attr == NULL || buf == NULL) {
+		dev_err(dev, "[%s] EINVAL\n", __func__);
+		return 0;
+	}
+
+	spin_lock_irqsave(udc->lock, flags);
+
+	n += scnprintf(buf + n, PAGE_SIZE - n,
+		       "status = %08x\n", hw_read_intr_status());
+	n += scnprintf(buf + n, PAGE_SIZE - n,
+		       "enable = %08x\n", hw_read_intr_enable());
+
+	n += scnprintf(buf + n, PAGE_SIZE - n, "*test = %d\n",
+		       isr_statistics.test);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "» ui  = %d\n",
+		       isr_statistics.ui);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "» uei = %d\n",
+		       isr_statistics.uei);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "» pci = %d\n",
+		       isr_statistics.pci);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "» uri = %d\n",
+		       isr_statistics.uri);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "» sli = %d\n",
+		       isr_statistics.sli);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "*none = %d\n",
+		       isr_statistics.none);
+	n += scnprintf(buf + n, PAGE_SIZE - n, "*hndl = %d\n",
+		       isr_statistics.hndl.cnt);
+
+	for (i = isr_statistics.hndl.idx, j = 0; j <= ISR_MASK; j++, i++) {
+		i   &= ISR_MASK;
+		intr = isr_statistics.hndl.buf[i];
+
+		if (USBi_UI  & intr)
+			n += scnprintf(buf + n, PAGE_SIZE - n, "ui  ");
+		intr &= ~USBi_UI;
+		if (USBi_UEI & intr)
+			n += scnprintf(buf + n, PAGE_SIZE - n, "uei ");
+		intr &= ~USBi_UEI;
+		if (USBi_PCI & intr)
+			n += scnprintf(buf + n, PAGE_SIZE - n, "pci ");
+		intr &= ~USBi_PCI;
+		if (USBi_URI & intr)
+			n += scnprintf(buf + n, PAGE_SIZE - n, "uri ");
+		intr &= ~USBi_URI;
+		if (USBi_SLI & intr)
+			n += scnprintf(buf + n, PAGE_SIZE - n, "sli ");
+		intr &= ~USBi_SLI;
+		if (intr)
+			n += scnprintf(buf + n, PAGE_SIZE - n, "??? ");
+		if (isr_statistics.hndl.buf[i])
+			n += scnprintf(buf + n, PAGE_SIZE - n, "\n");
+	}
+
+	spin_unlock_irqrestore(udc->lock, flags);
+
+	return n;
+}
+
+/**
+ * store_inters: enable & force or disable an individual interrutps
+ *                   (to be used for test purposes only)
+ *
+ * Check "device.h" for details
+ */
+static ssize_t store_inters(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct ci13xxx *udc = container_of(dev, struct ci13xxx, gadget.dev);
+	unsigned long flags;
+	unsigned en, bit;
+
+	dbg_trace("[%s] %p, %d\n", __func__, buf, count);
+	if (attr == NULL || buf == NULL) {
+		dev_err(dev, "[%s] EINVAL\n", __func__);
+		goto done;
+	}
+
+	if (sscanf(buf, "%u %u", &en, &bit) != 2 || en > 1) {
+		dev_err(dev, "<1|0> <bit>: enable|disable interrupt");
+		goto done;
+	}
+
+	spin_lock_irqsave(udc->lock, flags);
+	if (en) {
+		if (hw_intr_force(bit))
+			dev_err(dev, "invalid bit number\n");
+		else
+			isr_statistics.test++;
+	} else {
+		if (hw_intr_clear(bit))
+			dev_err(dev, "invalid bit number\n");
+	}
+	spin_unlock_irqrestore(udc->lock, flags);
+
+ done:
+	return count;
+}
+static DEVICE_ATTR(inters, S_IRUSR | S_IWUSR, show_inters, store_inters);
+
+/**
+ * show_port_test: reads port test mode
+ *
+ * Check "device.h" for details
+ */
+static ssize_t show_port_test(struct device *dev,
+