xref: /openbmc/u-boot/drivers/usb/musb/am35x.c (revision 4e3349b6)
1 /*
2  * am35x.c - TI's AM35x platform specific usb wrapper functions.
3  *
4  * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
5  *
6  * Based on drivers/usb/musb/da8xx.c
7  *
8  * Copyright (c) 2010 Texas Instruments Incorporated
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23  */
24 #include <common.h>
25 
26 #include "am35x.h"
27 
28 /* MUSB platform configuration */
29 struct musb_config musb_cfg = {
30 	.regs		= (struct musb_regs *)AM35X_USB_OTG_CORE_BASE,
31 	.timeout	= AM35X_USB_OTG_TIMEOUT,
32 	.musb_speed	= 0,
33 };
34 
35 /*
36  * Enable the USB phy
37  */
38 static u8 phy_on(void)
39 {
40 	u32 devconf2;
41 	u32 timeout;
42 
43 	devconf2 = readl(&am35x_scm_general_regs->devconf2);
44 
45 	devconf2 &= ~(DEVCONF2_RESET | DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN |
46 		      DEVCONF2_OTGMODE | DEVCONF2_REFFREQ |
47 		      DEVCONF2_PHY_GPIOMODE);
48 	devconf2 |= DEVCONF2_SESENDEN | DEVCONF2_VBDTCTEN | DEVCONF2_PHY_PLLON |
49 		    DEVCONF2_REFFREQ_13MHZ | DEVCONF2_DATPOL;
50 
51 	writel(devconf2, &am35x_scm_general_regs->devconf2);
52 
53 	/* wait until the USB phy is turned on */
54 	timeout = musb_cfg.timeout;
55 	while (timeout--)
56 		if (readl(&am35x_scm_general_regs->devconf2) & DEVCONF2_PHYCKGD)
57 			return 1;
58 
59 	/* USB phy was not turned on */
60 	return 0;
61 }
62 
63 /*
64  * Disable the USB phy
65  */
66 static void phy_off(void)
67 {
68 	u32 devconf2;
69 
70 	/*
71 	 * Power down the on-chip PHY.
72 	 */
73 	devconf2 = readl(&am35x_scm_general_regs->devconf2);
74 
75 	devconf2 &= ~DEVCONF2_PHY_PLLON;
76 	devconf2 |= DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN;
77 	writel(devconf2, &am35x_scm_general_regs->devconf2);
78 }
79 
80 /*
81  * This function performs platform specific initialization for usb0.
82  */
83 int musb_platform_init(void)
84 {
85 	u32 revision;
86 	u32 sw_reset;
87 
88 	/* global usb reset */
89 	sw_reset = readl(&am35x_scm_general_regs->ip_sw_reset);
90 	sw_reset |= (1 << 0);
91 	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
92 	sw_reset &= ~(1 << 0);
93 	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
94 
95 	/* reset the controller */
96 	writel(0x1, &am35x_usb_regs->control);
97 	udelay(5000);
98 
99 	/* start the on-chip usb phy and its pll */
100 	if (phy_on() == 0)
101 		return -1;
102 
103 	/* Returns zero if e.g. not clocked */
104 	revision = readl(&am35x_usb_regs->revision);
105 	if (revision == 0)
106 		return -1;
107 
108 	return 0;
109 }
110 
111 /*
112  * This function performs platform specific deinitialization for usb0.
113  */
114 void musb_platform_deinit(void)
115 {
116 	/* Turn off the phy */
117 	phy_off();
118 }
119 
120 /*
121  * This function reads data from endpoint fifo for AM35x
122  * which supports only 32bit read operation.
123  *
124  * ep           - endpoint number
125  * length       - number of bytes to read from FIFO
126  * fifo_data    - pointer to data buffer into which data is read
127  */
128 __attribute__((weak))
129 void read_fifo(u8 ep, u32 length, void *fifo_data)
130 {
131 	u8  *data = (u8 *)fifo_data;
132 	u32 val;
133 	int i;
134 
135 	/* select the endpoint index */
136 	writeb(ep, &musbr->index);
137 
138 	if (length > 4) {
139 		for (i = 0; i < (length >> 2); i++) {
140 			val = readl(&musbr->fifox[ep]);
141 			memcpy(data, &val, 4);
142 			data += 4;
143 		}
144 		length %= 4;
145 	}
146 	if (length > 0) {
147 		val = readl(&musbr->fifox[ep]);
148 		memcpy(data, &val, length);
149 	}
150 }
151