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|
/*
* Tahvo USB transceiver driver
*
* Copyright (C) 2005-2006 Nokia Corporation
*
* Parts copied from isp1301_omap.c.
* Copyright (C) 2004 Texas Instruments
* Copyright (C) 2004 David Brownell
*
* Original driver written by Juha Yrjölä, Tony Lindgren and Timo Teräs.
* Modified for Retu/Tahvo MFD by Aaro Koskinen.
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file "COPYING" in the main directory of this
* archive for more details.
*
* 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/io.h>
#include <linux/clk.h>
#include <linux/usb.h>
#include <linux/extcon.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/usb/otg.h>
#include <linux/mfd/retu.h>
#include <linux/usb/gadget.h>
#include <linux/platform_device.h>
#define DRIVER_NAME "tahvo-usb"
#define TAHVO_REG_IDSR 0x02
#define TAHVO_REG_USBR 0x06
#define USBR_SLAVE_CONTROL (1 << 8)
#define USBR_VPPVIO_SW (1 << 7)
#define USBR_SPEED (1 << 6)
#define USBR_REGOUT (1 << 5)
#define USBR_MASTER_SW2 (1 << 4)
#define USBR_MASTER_SW1 (1 << 3)
#define USBR_SLAVE_SW (1 << 2)
#define USBR_NSUSPEND (1 << 1)
#define USBR_SEMODE (1 << 0)
#define TAHVO_MODE_HOST 0
#define TAHVO_MODE_PERIPHERAL 1
struct tahvo_usb {
struct platform_device *pt_dev;
struct usb_phy phy;
int vbus_state;
struct mutex serialize;
struct clk *ick;
int irq;
int tahvo_mode;
struct extcon_dev extcon;
};
static const char *tahvo_cable[] = {
"USB-HOST",
"USB",
NULL,
};
static ssize_t vbus_state_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct tahvo_usb *tu = dev_get_drvdata(device);
return sprintf(buf, "%s\n", tu->vbus_state ? "on" : "off");
}
static DEVICE_ATTR(vbus, 0444, vbus_state_show, NULL);
static void check_vbus_state(struct tahvo_usb *tu)
{
struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
int reg, prev_state;
reg = retu_read(rdev, TAHVO_REG_IDSR);
if (reg & TAHVO_STAT_VBUS) {
switch (tu->phy.state) {
case OTG_STATE_B_IDLE:
/* Enable the gadget driver */
if (tu->phy.otg->gadget)
usb_gadget_vbus_connect(tu->phy.otg->gadget);
tu->phy.state = OTG_STATE_B_PERIPHERAL;
break;
case OTG_STATE_A_IDLE:
/*
* Session is now valid assuming the USB hub is driving
* Vbus.
*/
tu->phy.state = OTG_STATE_A_HOST;
break;
default:
break;
}
dev_info(&tu->pt_dev->dev, "USB cable connected\n");
} else {
switch (tu->phy.state) {
case OTG_STATE_B_PERIPHERAL:
if (tu->phy.otg->gadget)
usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
tu->phy.state = OTG_STATE_B_IDLE;
break;
case OTG_STATE_A_HOST:
tu->phy.state = OTG_STATE_A_IDLE;
break;
default:
break;
}
dev_info(&tu->pt_dev->dev, "USB cable disconnected\n");
}
prev_state = tu->vbus_state;
tu->vbus_state = reg & TAHVO_STAT_VBUS;
if (prev_state != tu->vbus_state) {
extcon_set_cable_state(&tu->extcon, "USB", tu->vbus_state);
sysfs_notify(&tu->pt_dev->dev.kobj, NULL, "vbus_state");
}
}
static void tahvo_usb_become_host(struct tahvo_usb *tu)
{
struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
extcon_set_cable_state(&tu->extcon, "USB-HOST", true);
/* Power up the transceiver in USB host mode */
retu_write(rdev, TAHVO_REG_USBR, USBR_REGOUT | USBR_NSUSPEND |
USBR_MASTER_SW2 | USBR_MASTER_SW1);
tu->phy.state = OTG_STATE_A_IDLE;
check_vbus_state(tu);
}
static void tahvo_usb_stop_host(struct tahvo_usb *tu)
{
tu->phy.state = OTG_STATE_A_IDLE;
}
static void tahvo_usb_become_peripheral(struct tahvo_usb *tu)
{
struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
extcon_set_cable_state(&tu->extcon, "USB-HOST", false);
/* Power up transceiver and set it in USB peripheral mode */
retu_write(rdev, TAHVO_REG_USBR, USBR_SLAVE_CONTROL | USBR_REGOUT |
USBR_NSUSPEND | USBR_SLAVE_SW);
tu->phy.state = OTG_STATE_B_IDLE;
check_vbus_state(tu);
}
static void tahvo_usb_stop_peripheral(struct tahvo_usb *tu)
{
if (tu->phy.otg->gadget)
usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
tu->phy.state = OTG_STATE_B_IDLE;
}
static void tahvo_usb_power_off(struct tahvo_usb *tu)
{
struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
/* Disable gadget controller if any */
if (tu->phy.otg->gadget)
usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
/* Power off transceiver */
retu_write(rdev, TAHVO_REG_USBR, 0);
tu->phy.state = OTG_STATE_UNDEFINED;
}
static int tahvo_usb_set_suspend(struct usb_phy *dev, int suspend)
{
struct tahvo_usb *tu = container_of(dev, struct tahvo_usb, phy);
struct retu_dev *rdev = dev_get_drvdata(tu->pt_dev->dev.parent);
u16 w;
dev_dbg(&tu->pt_dev->dev, "%s\n", __func__);
w = retu_read(rdev, TAHVO_REG_USBR);
if (suspend)
w &= ~USBR_NSUSPEND;
else
w |= USBR_NSUSPEND;
retu_write(rdev, TAHVO_REG_USBR, w);
return 0;
}
static int tahvo_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
{
struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, host);
mutex_lock(&tu->serialize);
if (host == NULL) {
if (tu->tahvo_mode == TAHVO_MODE_HOST)
tahvo_usb_power_off(tu);
otg->host = NULL;
mutex_unlock(&tu->serialize);
return 0;
}
if (tu->tahvo_mode == TAHVO_MODE_HOST) {
otg->host = NULL;
tahvo_usb_become_host(tu);
}
otg->host = host;
mutex_unlock(&tu->serialize);
return 0;
}
static int tahvo_usb_set_peripheral(struct usb_otg *otg,
struct usb_gadget *gadget)
{
struct tahvo_usb *tu = container_of(otg->phy, struct tahvo_usb, phy);
dev_dbg(&tu->pt_dev->dev, "%s %p\n", __func__, gadget);
mutex_lock(&tu->serialize);
if (!gadget) {
if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
tahvo_usb_power_off(tu);
tu->phy.otg->gadget = NULL;
mutex_unlock(&tu->serialize);
return 0;
}
tu->phy.otg->gadget = gadget;
if (tu->tahvo_mode == TAHVO_MODE_PERIPHERAL)
tahvo_usb_become_peripheral(tu);
mutex_unlock(&tu->serialize);
return 0;
}
static irqreturn_t tahvo_usb_vbus_interrupt(int irq, void *_tu)
{
struct tahvo_usb *tu = _tu;
mutex_lock(&tu->serialize);
check_vbus_state(tu);
mutex_unlock(&tu->serialize);
return IRQ_HANDLED;
}
static ssize_t otg_mode_show(struct device *device,
struct device_attribute *attr,
|