linux/drivers/usb/dwc3/ulpi.c

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/**
* ulpi.c - DesignWare USB3 Controller's ULPI PHY interface
*
* Copyright (C) 2015 Intel Corporation
*
* Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
*
* 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.
*/
#include <linux/ulpi/regs.h>
#include "core.h"
#include "io.h"
#define DWC3_ULPI_ADDR(a) \
((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
static int dwc3_ulpi_busyloop(struct dwc3 *dwc)
{
unsigned count = 1000;
u32 reg;
while (count--) {
reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
if (!(reg & DWC3_GUSB2PHYACC_BUSY))
return 0;
cpu_relax();
}
return -ETIMEDOUT;
}
static int dwc3_ulpi_read(struct device *dev, u8 addr)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
u32 reg;
int ret;
reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
}
reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
ret = dwc3_ulpi_busyloop(dwc);
if (ret)
return ret;
reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
return DWC3_GUSB2PHYACC_DATA(reg);
}
static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
{
struct dwc3 *dwc = dev_get_drvdata(dev);
u32 reg;
reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
}
reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
reg |= DWC3_GUSB2PHYACC_WRITE | val;
dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
return dwc3_ulpi_busyloop(dwc);
}
static const struct ulpi_ops dwc3_ulpi_ops = {
.read = dwc3_ulpi_read,
.write = dwc3_ulpi_write,
};
int dwc3_ulpi_init(struct dwc3 *dwc)
{
/* Register the interface */
dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
if (IS_ERR(dwc->ulpi)) {
dev_err(dwc->dev, "failed to register ULPI interface");
return PTR_ERR(dwc->ulpi);
}
return 0;
}
void dwc3_ulpi_exit(struct dwc3 *dwc)
{
if (dwc->ulpi) {
ulpi_unregister_interface(dwc->ulpi);
dwc->ulpi = NULL;
}
}