1/*
2 * Copyright (C) 2011 Google, Inc.
3 *
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 *
13 */
14
15#include <linux/export.h>
16#include <linux/kernel.h>
17#include <linux/usb.h>
18#include <linux/io.h>
19#include <linux/usb/otg.h>
20#include <linux/usb/ulpi.h>
21
22#define ULPI_VIEW_WAKEUP	(1 << 31)
23#define ULPI_VIEW_RUN		(1 << 30)
24#define ULPI_VIEW_WRITE		(1 << 29)
25#define ULPI_VIEW_READ		(0 << 29)
26#define ULPI_VIEW_ADDR(x)	(((x) & 0xff) << 16)
27#define ULPI_VIEW_DATA_READ(x)	(((x) >> 8) & 0xff)
28#define ULPI_VIEW_DATA_WRITE(x)	((x) & 0xff)
29
30static int ulpi_viewport_wait(void __iomem *view, u32 mask)
31{
32	unsigned long usec = 2000;
33
34	while (usec--) {
35		if (!(readl(view) & mask))
36			return 0;
37
38		udelay(1);
39	}
40
41	return -ETIMEDOUT;
42}
43
44static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
45{
46	int ret;
47	void __iomem *view = otg->io_priv;
48
49	writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
50	ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
51	if (ret)
52		return ret;
53
54	writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
55	ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
56	if (ret)
57		return ret;
58
59	return ULPI_VIEW_DATA_READ(readl(view));
60}
61
62static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
63{
64	int ret;
65	void __iomem *view = otg->io_priv;
66
67	writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
68	ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
69	if (ret)
70		return ret;
71
72	writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
73						 ULPI_VIEW_ADDR(reg), view);
74
75	return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
76}
77
78struct usb_phy_io_ops ulpi_viewport_access_ops = {
79	.read	= ulpi_viewport_read,
80	.write	= ulpi_viewport_write,
81};
82EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);
83