1 /*
2  * OMAP ulpi viewport support
3  * Based on drivers/usb/ulpi/ulpi-viewport.c
4  *
5  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com
6  * Author: Govindraj R <govindraj.raja@ti.com>
7  *
8  * This program is free software: you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2  of
10  * the License as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program. If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <common.h>
22 #include <asm/io.h>
23 #include <usb/ulpi.h>
24 
25 #define OMAP_ULPI_WR_OPSEL	(3 << 21)
26 #define OMAP_ULPI_ACCESS	(1 << 31)
27 
28 /*
29  * Wait for the ULPI Access to complete
30  */
31 static int ulpi_wait(struct ulpi_viewport *ulpi_vp, u32 mask)
32 {
33 	int timeout = CONFIG_USB_ULPI_TIMEOUT;
34 
35 	while (--timeout) {
36 		if ((readl(ulpi_vp->viewport_addr) & mask))
37 			return 0;
38 
39 		udelay(1);
40 	}
41 
42 	return ULPI_ERROR;
43 }
44 
45 /*
46  * Wake the ULPI PHY up for communication
47  *
48  * returns 0 on success.
49  */
50 static int ulpi_wakeup(struct ulpi_viewport *ulpi_vp)
51 {
52 	int err;
53 
54 	if (readl(ulpi_vp->viewport_addr) & OMAP_ULPI_ACCESS)
55 		return 0; /* already awake */
56 
57 	writel(OMAP_ULPI_ACCESS, ulpi_vp->viewport_addr);
58 
59 	err = ulpi_wait(ulpi_vp, OMAP_ULPI_ACCESS);
60 	if (err)
61 		debug("ULPI wakeup timed out\n");
62 
63 	return err;
64 }
65 
66 /*
67  * Issue a ULPI read/write request
68  */
69 static int ulpi_request(struct ulpi_viewport *ulpi_vp, u32 value)
70 {
71 	int err;
72 
73 	err = ulpi_wakeup(ulpi_vp);
74 	if (err)
75 		return err;
76 
77 	writel(value, ulpi_vp->viewport_addr);
78 
79 	err = ulpi_wait(ulpi_vp, OMAP_ULPI_ACCESS);
80 	if (err)
81 		debug("ULPI request timed out\n");
82 
83 	return err;
84 }
85 
86 int ulpi_write(struct ulpi_viewport *ulpi_vp, u8 *reg, u32 value)
87 {
88 	u32 val = ((ulpi_vp->port_num & 0xf) << 24) |
89 			OMAP_ULPI_WR_OPSEL | ((u32)reg << 16) | (value & 0xff);
90 
91 	return ulpi_request(ulpi_vp, val);
92 }
93 
94 u32 ulpi_read(struct ulpi_viewport *ulpi_vp, u8 *reg)
95 {
96 	int err;
97 	u32 val = ((ulpi_vp->port_num & 0xf) << 24) |
98 			 OMAP_ULPI_WR_OPSEL | ((u32)reg << 16);
99 
100 	err = ulpi_request(ulpi_vp, val);
101 	if (err)
102 		return err;
103 
104 	return readl(ulpi_vp->viewport_addr) & 0xff;
105 }
106