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/iopoll.h>
11 #include <linux/usb/otg.h>
12 #include <linux/usb/ulpi.h>
13
14 #define ULPI_VIEW_WAKEUP (1 << 31)
15 #define ULPI_VIEW_RUN (1 << 30)
16 #define ULPI_VIEW_WRITE (1 << 29)
17 #define ULPI_VIEW_READ (0 << 29)
18 #define ULPI_VIEW_ADDR(x) (((x) & 0xff) << 16)
19 #define ULPI_VIEW_DATA_READ(x) (((x) >> 8) & 0xff)
20 #define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff)
21
ulpi_viewport_wait(void __iomem * view,u32 mask)22 static int ulpi_viewport_wait(void __iomem *view, u32 mask)
23 {
24 u32 val;
25
26 return readl_poll_timeout_atomic(view, val, !(val & mask), 1, 2000);
27 }
28
ulpi_viewport_read(struct usb_phy * otg,u32 reg)29 static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
30 {
31 int ret;
32 void __iomem *view = otg->io_priv;
33
34 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
35 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
36 if (ret)
37 return ret;
38
39 writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
40 ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
41 if (ret)
42 return ret;
43
44 return ULPI_VIEW_DATA_READ(readl(view));
45 }
46
ulpi_viewport_write(struct usb_phy * otg,u32 val,u32 reg)47 static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
48 {
49 int ret;
50 void __iomem *view = otg->io_priv;
51
52 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
53 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
54 if (ret)
55 return ret;
56
57 writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
58 ULPI_VIEW_ADDR(reg), view);
59
60 return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
61 }
62
63 struct usb_phy_io_ops ulpi_viewport_access_ops = {
64 .read = ulpi_viewport_read,
65 .write = ulpi_viewport_write,
66 };
67 EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);
68