1 /*
2  * Copyright (C) 2011 Jana Rapava <fermata7@gmail.com>
3  * Copyright (C) 2011 CompuLab, Ltd. <www.compulab.co.il>
4  *
5  * Authors: Jana Rapava <fermata7@gmail.com>
6  *	    Igor Grinberg <grinberg@compulab.co.il>
7  *
8  * Based on:
9  * linux/drivers/usb/otg/ulpi_viewport.c
10  *
11  * Original Copyright follow:
12  * Copyright (C) 2011 Google, Inc.
13  *
14  * This software is licensed under the terms of the GNU General Public
15  * License version 2, as published by the Free Software Foundation, and
16  * may be copied, distributed, and modified under those terms.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  */
24 
25 #include <common.h>
26 #include <asm/io.h>
27 #include <usb/ulpi.h>
28 
29 /* ULPI viewport control bits */
30 #define ULPI_SS		(1 << 27)
31 #define ULPI_RWCTRL	(1 << 29)
32 #define ULPI_RWRUN	(1 << 30)
33 #define ULPI_WU		(1 << 31)
34 
35 /*
36  * Wait for the ULPI request to complete
37  *
38  * @ulpi_viewport	- the address of the viewport
39  * @mask		- expected value to wait for
40  *
41  * returns 0 on mask match, ULPI_ERROR on time out.
42  */
43 static int ulpi_wait(u32 ulpi_viewport, u32 mask)
44 {
45 	int timeout = CONFIG_USB_ULPI_TIMEOUT;
46 
47 	/* Wait for the bits in mask to become zero. */
48 	while (--timeout) {
49 		if ((readl(ulpi_viewport) & mask) == 0)
50 			return 0;
51 
52 		udelay(1);
53 	}
54 
55 	return ULPI_ERROR;
56 }
57 
58 /*
59  * Wake the ULPI PHY up for communication
60  *
61  * returns 0 on success.
62  */
63 static int ulpi_wakeup(u32 ulpi_viewport)
64 {
65 	int err;
66 
67 	if (readl(ulpi_viewport) & ULPI_SS)
68 		return 0; /* already awake */
69 
70 	writel(ULPI_WU, ulpi_viewport);
71 
72 	err = ulpi_wait(ulpi_viewport, ULPI_WU);
73 	if (err)
74 		printf("ULPI wakeup timed out\n");
75 
76 	return err;
77 }
78 
79 /*
80  * Issue a ULPI read/write request
81  *
82  * @value - the ULPI request
83  */
84 static int ulpi_request(u32 ulpi_viewport, u32 value)
85 {
86 	int err;
87 
88 	err = ulpi_wakeup(ulpi_viewport);
89 	if (err)
90 		return err;
91 
92 	writel(value, ulpi_viewport);
93 
94 	err = ulpi_wait(ulpi_viewport, ULPI_RWRUN);
95 	if (err)
96 		printf("ULPI request timed out\n");
97 
98 	return err;
99 }
100 
101 int ulpi_write(u32 ulpi_viewport, u8 *reg, u32 value)
102 {
103 	u32 val = ULPI_RWRUN | ULPI_RWCTRL | ((u32)reg << 16) | (value & 0xff);
104 
105 	return ulpi_request(ulpi_viewport, val);
106 }
107 
108 u32 ulpi_read(u32 ulpi_viewport, u8 *reg)
109 {
110 	int err;
111 	u32 val = ULPI_RWRUN | ((u32)reg << 16);
112 
113 	err = ulpi_request(ulpi_viewport, val);
114 	if (err)
115 		return err;
116 
117 	return (readl(ulpi_viewport) >> 8) & 0xff;
118 }
119