tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2011 Google, Inc.
4 */
5
6#include <linux/export.h>
7#include <linux/kernel.h>
8#include <linux/usb.h>
9#include <linux/io.h>
10#include <linux/usb/otg.h>
11#include <linux/usb/ulpi.h>
12
13#define ULPI_VIEW_WAKEUP (1 << 31)
14#define ULPI_VIEW_RUN (1 << 30)
15#define ULPI_VIEW_WRITE (1 << 29)
16#define ULPI_VIEW_READ (0 << 29)
17#define ULPI_VIEW_ADDR(x) (((x) & 0xff) << 16)
18#define ULPI_VIEW_DATA_READ(x) (((x) >> 8) & 0xff)
19#define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff)
20
21static int ulpi_viewport_wait(void __iomem *view, u32 mask)
22{
23 unsigned long usec = 2000;
24
25 while (usec--) {
26 if (!(readl(view) & mask))
27 return 0;
28
29 udelay(1);
30 }
31
32 return -ETIMEDOUT;
33}
34
35static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
36{
37 int ret;
38 void __iomem *view = otg->io_priv;
39
40 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
41 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
42 if (ret)
43 return ret;
44
45 writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
46 ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
47 if (ret)
48 return ret;
49
50 return ULPI_VIEW_DATA_READ(readl(view));
51}
52
53static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
54{
55 int ret;
56 void __iomem *view = otg->io_priv;
57
58 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
59 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
60 if (ret)
61 return ret;
62
63 writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
64 ULPI_VIEW_ADDR(reg), view);
65
66 return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
67}
68
69struct usb_phy_io_ops ulpi_viewport_access_ops = {
70 .read = ulpi_viewport_read,
71 .write = ulpi_viewport_write,
72};
73EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);