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  * SPDX-License-Identifier:	GPL-2.0
15  */
16 
17 #include <common.h>
18 #include <asm/io.h>
19 #include <usb/ulpi.h>
20 
21 /* ULPI viewport control bits */
22 #define ULPI_SS		(1 << 27)
23 #define ULPI_RWCTRL	(1 << 29)
24 #define ULPI_RWRUN	(1 << 30)
25 #define ULPI_WU		(1 << 31)
26 
27 /*
28  * Wait for the ULPI request to complete
29  *
30  * @ulpi_viewport	- the address of the viewport
31  * @mask		- expected value to wait for
32  *
33  * returns 0 on mask match, ULPI_ERROR on time out.
34  */
35 static int ulpi_wait(struct ulpi_viewport *ulpi_vp, u32 mask)
36 {
37 	int timeout = CONFIG_USB_ULPI_TIMEOUT;
38 
39 	/* Wait for the bits in mask to become zero. */
40 	while (--timeout) {
41 		if ((readl(ulpi_vp->viewport_addr) & mask) == 0)
42 			return 0;
43 
44 		udelay(1);
45 	}
46 
47 	return ULPI_ERROR;
48 }
49 
50 /*
51  * Wake the ULPI PHY up for communication
52  *
53  * returns 0 on success.
54  */
55 static int ulpi_wakeup(struct ulpi_viewport *ulpi_vp)
56 {
57 	int err;
58 
59 	if (readl(ulpi_vp->viewport_addr) & ULPI_SS)
60 		return 0; /* already awake */
61 
62 	writel(ULPI_WU, ulpi_vp->viewport_addr);
63 
64 	err = ulpi_wait(ulpi_vp, ULPI_WU);
65 	if (err)
66 		printf("ULPI wakeup timed out\n");
67 
68 	return err;
69 }
70 
71 /*
72  * Issue a ULPI read/write request
73  *
74  * @value - the ULPI request
75  */
76 static int ulpi_request(struct ulpi_viewport *ulpi_vp, u32 value)
77 {
78 	int err;
79 
80 	err = ulpi_wakeup(ulpi_vp);
81 	if (err)
82 		return err;
83 
84 	writel(value, ulpi_vp->viewport_addr);
85 
86 	err = ulpi_wait(ulpi_vp, ULPI_RWRUN);
87 	if (err)
88 		printf("ULPI request timed out\n");
89 
90 	return err;
91 }
92 
93 int ulpi_write(struct ulpi_viewport *ulpi_vp, u8 *reg, u32 value)
94 {
95 	u32 val = ULPI_RWRUN | ULPI_RWCTRL | ((u32)reg << 16) | (value & 0xff);
96 
97 	val |= (ulpi_vp->port_num & 0x7) << 24;
98 	return ulpi_request(ulpi_vp, val);
99 }
100 
101 u32 ulpi_read(struct ulpi_viewport *ulpi_vp, u8 *reg)
102 {
103 	int err;
104 	u32 val = ULPI_RWRUN | ((u32)reg << 16);
105 
106 	val |= (ulpi_vp->port_num & 0x7) << 24;
107 	err = ulpi_request(ulpi_vp, val);
108 	if (err)
109 		return err;
110 
111 	return (readl(ulpi_vp->viewport_addr) >> 8) & 0xff;
112 }
113