linux/drivers/usb/phy/phy-ulpi-viewport.c

74 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2011 Google, Inc.
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/io.h>
#include <linux/usb/otg.h>
#include <linux/usb/ulpi.h>
#define ULPI_VIEW_WAKEUP (1 << 31)
#define ULPI_VIEW_RUN (1 << 30)
#define ULPI_VIEW_WRITE (1 << 29)
#define ULPI_VIEW_READ (0 << 29)
#define ULPI_VIEW_ADDR(x) (((x) & 0xff) << 16)
#define ULPI_VIEW_DATA_READ(x) (((x) >> 8) & 0xff)
#define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff)
static int ulpi_viewport_wait(void __iomem *view, u32 mask)
{
unsigned long usec = 2000;
while (usec--) {
if (!(readl(view) & mask))
return 0;
udelay(1);
}
return -ETIMEDOUT;
}
static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
{
int ret;
void __iomem *view = otg->io_priv;
writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
if (ret)
return ret;
writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
if (ret)
return ret;
return ULPI_VIEW_DATA_READ(readl(view));
}
static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
{
int ret;
void __iomem *view = otg->io_priv;
writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
if (ret)
return ret;
writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
ULPI_VIEW_ADDR(reg), view);
return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
}
struct usb_phy_io_ops ulpi_viewport_access_ops = {
.read = ulpi_viewport_read,
.write = ulpi_viewport_write,
};
EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);