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 | |
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 | |
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, addr: 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), addr: 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 | |
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, addr: 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), addr: 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 | |