linux/drivers/usb/chipidea/ulpi.c

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/*
* Copyright (c) 2016 Linaro Ltd.
*
* 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/device.h>
#include <linux/usb/chipidea.h>
#include <linux/ulpi/interface.h>
#include "ci.h"
#define ULPI_WAKEUP BIT(31)
#define ULPI_RUN BIT(30)
#define ULPI_WRITE BIT(29)
#define ULPI_SYNC_STATE BIT(27)
#define ULPI_ADDR(n) ((n) << 16)
#define ULPI_DATA(n) (n)
static int ci_ulpi_wait(struct ci_hdrc *ci, u32 mask)
{
unsigned long usec = 10000;
while (usec--) {
if (!hw_read(ci, OP_ULPI_VIEWPORT, mask))
return 0;
udelay(1);
}
return -ETIMEDOUT;
}
static int ci_ulpi_read(struct device *dev, u8 addr)
{
struct ci_hdrc *ci = dev_get_drvdata(dev);
int ret;
hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_WRITE | ULPI_WAKEUP);
ret = ci_ulpi_wait(ci, ULPI_WAKEUP);
if (ret)
return ret;
hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_RUN | ULPI_ADDR(addr));
ret = ci_ulpi_wait(ci, ULPI_RUN);
if (ret)
return ret;
return hw_read(ci, OP_ULPI_VIEWPORT, GENMASK(15, 8)) >> 8;
}
static int ci_ulpi_write(struct device *dev, u8 addr, u8 val)
{
struct ci_hdrc *ci = dev_get_drvdata(dev);
int ret;
hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff, ULPI_WRITE | ULPI_WAKEUP);
ret = ci_ulpi_wait(ci, ULPI_WAKEUP);
if (ret)
return ret;
hw_write(ci, OP_ULPI_VIEWPORT, 0xffffffff,
ULPI_RUN | ULPI_WRITE | ULPI_ADDR(addr) | val);
return ci_ulpi_wait(ci, ULPI_RUN);
}
int ci_ulpi_init(struct ci_hdrc *ci)
{
if (ci->platdata->phy_mode != USBPHY_INTERFACE_MODE_ULPI)
return 0;
/*
* Set PORTSC correctly so we can read/write ULPI registers for
* identification purposes
*/
hw_phymode_configure(ci);
ci->ulpi_ops.read = ci_ulpi_read;
ci->ulpi_ops.write = ci_ulpi_write;
ci->ulpi = ulpi_register_interface(ci->dev, &ci->ulpi_ops);
if (IS_ERR(ci->ulpi))
dev_err(ci->dev, "failed to register ULPI interface");
return PTR_ERR_OR_ZERO(ci->ulpi);
}
void ci_ulpi_exit(struct ci_hdrc *ci)
{
if (ci->ulpi) {
ulpi_unregister_interface(ci->ulpi);
ci->ulpi = NULL;
}
}
int ci_ulpi_resume(struct ci_hdrc *ci)
{
int cnt = 100000;
while (cnt-- > 0) {
if (hw_read(ci, OP_ULPI_VIEWPORT, ULPI_SYNC_STATE))
return 0;
udelay(1);
}
return -ETIMEDOUT;
}