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/*
* drivers/usb/otg/tegra-otg.c
*
* OTG transceiver driver for Tegra UTMI phy
*
* Copyright (C) 2010 NVIDIA Corp.
* Copyright (C) 2010 Google, Inc.
*
* 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.
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/usb.h>
#include <linux/usb/otg.h>
#include <linux/usb/gadget.h>
#include <linux/usb/hcd.h>
#include <linux/platform_device.h>
#include <linux/platform_data/tegra_usb.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/err.h>
#define USB_PHY_WAKEUP 0x408
#define USB_ID_INT_EN (1 << 0)
#define USB_ID_INT_STATUS (1 << 1)
#define USB_ID_STATUS (1 << 2)
#define USB_ID_PIN_WAKEUP_EN (1 << 6)
#define USB_VBUS_WAKEUP_EN (1 << 30)
#define USB_VBUS_INT_EN (1 << 8)
#define USB_VBUS_INT_STATUS (1 << 9)
#define USB_VBUS_STATUS (1 << 10)
#define USB_INTS (USB_VBUS_INT_STATUS | USB_ID_INT_STATUS)
struct tegra_otg_data {
struct otg_transceiver otg;
unsigned long int_status;
spinlock_t lock;
void __iomem *regs;
struct clk *clk;
int irq;
struct platform_device *host;
struct platform_device *pdev;
struct work_struct work;
unsigned int intr_reg_data;
};
static inline unsigned long otg_readl(struct tegra_otg_data *tegra,
unsigned int offset)
{
return readl(tegra->regs + offset);
}
static inline void otg_writel(struct tegra_otg_data *tegra, unsigned long val,
unsigned int offset)
{
writel(val, tegra->regs + offset);
}
static const char *tegra_state_name(enum usb_otg_state state)
{
if (state == OTG_STATE_A_HOST)
return "HOST";
if (state == OTG_STATE_B_PERIPHERAL)
return "PERIPHERAL";
if (state == OTG_STATE_A_SUSPEND)
return "SUSPEND";
return "INVALID";
}
void tegra_start_host(struct tegra_otg_data *tegra)
{
struct tegra_otg_platform_data *pdata = tegra->otg.dev->platform_data;
if (!tegra->pdev) {
tegra->pdev = pdata->host_register();
}
}
void tegra_stop_host(struct tegra_otg_data *tegra)
{
struct tegra_otg_platform_data *pdata = tegra->otg.dev->platform_data;
if (tegra->pdev) {
pdata->host_unregister(tegra->pdev);
tegra->pdev = NULL;
}
}
static void irq_work(struct work_struct *work)
{
struct tegra_otg_data *tegra =
container_of(work, struct tegra_otg_data, work);
struct otg_transceiver *otg = &tegra->otg;
enum usb_otg_state from = otg->state;
enum usb_otg_state to = OTG_STATE_UNDEFINED;
unsigned long flags;
unsigned long status;
clk_enable(tegra->clk);
spin_lock_irqsave(&tegra->lock, flags);
status = tegra->int_status;
if (tegra->int_status & USB_ID_INT_STATUS) {
if (status & USB_ID_STATUS) {
if ((status & USB_VBUS_STATUS) && (from != OTG_STATE_A_HOST))
to = OTG_STATE_B_PERIPHERAL;
else
to = OTG_STATE_A_SUSPEND;
}
else
to = OTG_STATE_A_HOST;
}
if (from != OTG_STATE_A_HOST) {
if (tegra->int_status & USB_VBUS_INT_STATUS) {
if (status & USB_VBUS_STATUS)
to = OTG_STATE_B_PERIPHERAL;
else
to = OTG_STATE_A_SUSPEND;
}
}
spin_unlock_irqrestore(&tegra->lock, flags);
if (to != OTG_STATE_UNDEFINED) {
otg->state = to;
dev_info(tegra->otg.dev, "%s --> %s\n", tegra_state_name(from),
tegra_state_name(to));
if (to == OTG_STATE_A_SUSPEND) {
if (from == OTG_STATE_A_HOST)
tegra_stop_host(tegra);
else if (from == OTG_STATE_B_PERIPHERAL && otg->gadget)
usb_gadget_vbus_disconnect(otg->gadget);
} else if (to == OTG_STATE_B_PERIPHERAL && otg->gadget) {
if (from == OTG_STATE_A_SUSPEND)
usb_gadget_vbus_connect(otg->gadget);
} else if (to == OTG_STATE_A_HOST) {
if (from == OTG_STATE_A_SUSPEND)
tegra_start_host(tegra);
}
}
clk_disable(tegra->clk);
}
static irqreturn_t tegra_otg_irq(int irq, void *data)
{
struct tegra_otg_data *tegra = data;
unsigned long flags;
unsigned long val;
spin_lock_irqsave(&tegra->lock, flags);
val = otg_readl(tegra, USB_PHY_WAKEUP);
otg_writel(tegra, val, USB_PHY_WAKEUP);
if ((val & USB_ID_INT_STATUS) || (val & USB_VBUS_INT_STATUS)) {
tegra->int_status = val;
schedule_work(&tegra->work);
}
spin_unlock_irqrestore(&tegra->lock, flags);
return IRQ_HANDLED;
}
static int tegra_otg_set_peripheral(struct otg_transceiver *otg,
struct usb_gadget *gadget)
{
struct tegra_otg_data *tegra;
unsigned long val;
tegra = container_of(otg, struct tegra_otg_data, otg);
otg->gadget = gadget;
clk_enable(tegra->clk);
val = otg_readl(tegra, USB_PHY_WAKEUP);
val |= (USB_VBUS_INT_EN | USB_VBUS_WAKEUP_EN);
val |= (USB_ID_INT_EN | USB_ID_PIN_WAKEUP_EN);
otg_writel(tegra, val, USB_PHY_WAKEUP);
clk_disable(tegra->clk);
if ((val & USB_ID_STATUS) && (val & USB_VBUS_STATUS)) {
val |= USB_VBUS_INT_STATUS;
} else if (!(val & USB_ID_STATUS)) {
val |= USB_ID_INT_STATUS;
} else {
val &= ~(USB_ID_INT_STATUS | USB_VBUS_INT_STATUS);
}
if ((val & USB_ID_INT_STATUS) || (val & USB_VBUS_INT_STATUS)) {
tegra->int_status = val;
schedule_work (&tegra->work);
}
return 0;
}
static int tegra_otg_set_host(struct otg_transceiver *otg,
struct usb_bus *host)
{
struct tegra_otg_data *tegra;
unsigned long val;
tegra = container_of(otg, struct tegra_otg_data, otg);
otg->host = host;
clk_enable(tegra->clk);
val = otg_readl(tegra, USB_PHY_WAKEUP);
val &= ~(USB_VBUS_INT_STATUS | USB_ID_INT_STATUS);
val |= (USB_ID_INT_EN | USB_ID_PIN_WAKEUP_EN);
otg_writel(tegra, val, USB_PHY_WAKEUP);
clk_disable(tegra->clk);
return 0;
}
static int tegra_otg_set_power(struct otg_transceiver *otg, unsigned mA)
{
return 0;
}
static int tegra_otg_set_suspend(struct otg_transceiver *otg, int suspend)
{
return 0;
}
static int tegra_otg_probe(struct platform_device *pdev)
{
struct tegra_otg_data *tegra;
struct resource *res;
int err;
tegra = kzalloc(sizeof(struct tegra_otg_data), GFP_KERNEL);
if (!tegra)
return -ENOMEM;
tegra->otg.dev = &pdev->dev;
tegra->otg.label = "tegra-otg";
tegra->otg.state = OTG_STATE_UNDEFINED;
tegra->otg.set_host = tegra_otg_set_host;
tegra->otg.set_peripheral = tegra_otg_set_peripheral;
tegra->otg.set_suspend = tegra_otg_set_suspend;
tegra->otg.set_power = tegra_otg_set_power;
spin_lock_init(&tegra->lock);
platform_set_drvdata(pdev, tegra);
tegra->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(tegra->clk)) {
dev_err(&pdev->dev, "Can't get otg clock\n");
err = PTR_ERR(tegra->clk);
goto err_clk;
}
err = clk_enable(tegra->clk);
if (err)
goto err_clken;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "Failed to get I/O memory\n");
err = -ENXIO;
goto err_io;
}
tegra->regs = ioremap(res->start, resource_size(res));
if (!tegra->regs) {
err = -ENOMEM;
goto err_io;
}
tegra->otg.state = OTG_STATE_A_SUSPEND;
err = otg_set_transceiver(&tegra->otg);
if (err) {
dev_err(&pdev->dev, "can't register transceiver (%d)\n", err);
goto err_otg;
}
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(&pdev->dev, "Failed to get IRQ\n");
err = -ENXIO;
goto err_irq;
}
tegra->irq = res->start;
err = request_threaded_irq(tegra->irq, tegra_otg_irq,
NULL,
IRQF_SHARED, "tegra-otg", tegra);
if (err) {
dev_err(&pdev->dev, "Failed to register IRQ\n");
goto err_irq;
}
INIT_WORK (&tegra->work, irq_work);
dev_info(&pdev->dev, "otg transceiver registered\n");
clk_disable(tegra->clk);
return 0;
err_irq:
otg_set_transceiver(NULL);
err_otg:
iounmap(tegra->regs);
err_io:
clk_disable(tegra->clk);
err_clken:
clk_put(tegra->clk);
err_clk:
platform_set_drvdata(pdev, NULL);
kfree(tegra);
return err;
}
static int __exit tegra_otg_remove(struct platform_device *pdev)
{
struct tegra_otg_data *tegra = platform_get_drvdata(pdev);
free_irq(tegra->irq, tegra);
otg_set_transceiver(NULL);
iounmap(tegra->regs);
clk_disable(tegra->clk);
clk_put(tegra->clk);
platform_set_drvdata(pdev, NULL);
kfree(tegra);
return 0;
}
#ifdef CONFIG_PM
static int tegra_otg_suspend(struct platform_device *pdev, pm_message_t state)
{
struct tegra_otg_data *tegra_otg = platform_get_drvdata(pdev);
/* store the interupt enable for cable ID and VBUS */
tegra_otg->intr_reg_data = readl(tegra_otg->regs + USB_PHY_WAKEUP);
return 0;
}
static int tegra_otg_resume(struct platform_device * pdev)
{
struct tegra_otg_data *tegra_otg = platform_get_drvdata(pdev);
/* restore the interupt enable for cable ID and VBUS */
writel(tegra_otg->intr_reg_data, (tegra_otg->regs + USB_PHY_WAKEUP));
return 0;
}
#endif
static struct platform_driver tegra_otg_driver = {
.driver = {
.name = "tegra-otg",
},
.remove = __exit_p(tegra_otg_remove),
.probe = tegra_otg_probe,
#ifdef CONFIG_PM
.suspend = tegra_otg_suspend,
.resume = tegra_otg_resume,
#endif
};
static int __init tegra_otg_init(void)
{
return platform_driver_register(&tegra_otg_driver);
}
subsys_initcall(tegra_otg_init);
static void __exit tegra_otg_exit(void)
{
platform_driver_unregister(&tegra_otg_driver);
}
module_exit(tegra_otg_exit);
|