linux/drivers/usb/otg/ulpi_viewport.c
Benoit Goby ee398ba97d usb: otg: Add ulpi viewport access ops
Add generic access ops for controllers with a ulpi viewport register
(e.g. Chipidea/ARC based controllers).

Signed-off-by: Benoit Goby <benoit@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-11 14:22:10 -08:00

81 lines
2.0 KiB
C

/*
* Copyright (C) 2011 Google, Inc.
*
* 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/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 otg_transceiver *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 otg_transceiver *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 otg_io_access_ops ulpi_viewport_access_ops = {
.read = ulpi_viewport_read,
.write = ulpi_viewport_write,
};