xref: /openbmc/u-boot/drivers/usb/musb/am35x.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * am35x.c - TI's AM35x platform specific usb wrapper functions.
4  *
5  * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
6  *
7  * Based on drivers/usb/musb/da8xx.c
8  *
9  * Copyright (c) 2010 Texas Instruments Incorporated
10  */
11 
12 #include <common.h>
13 
14 #include "am35x.h"
15 
16 /* MUSB platform configuration */
17 struct musb_config musb_cfg = {
18 	.regs		= (struct musb_regs *)AM35X_USB_OTG_CORE_BASE,
19 	.timeout	= AM35X_USB_OTG_TIMEOUT,
20 	.musb_speed	= 0,
21 };
22 
23 /*
24  * Enable the USB phy
25  */
26 static u8 phy_on(void)
27 {
28 	u32 devconf2;
29 	u32 timeout;
30 
31 	devconf2 = readl(&am35x_scm_general_regs->devconf2);
32 
33 	devconf2 &= ~(DEVCONF2_RESET | DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN |
34 		      DEVCONF2_OTGMODE | DEVCONF2_REFFREQ |
35 		      DEVCONF2_PHY_GPIOMODE);
36 	devconf2 |= DEVCONF2_SESENDEN | DEVCONF2_VBDTCTEN | DEVCONF2_PHY_PLLON |
37 		    DEVCONF2_REFFREQ_13MHZ | DEVCONF2_DATPOL;
38 
39 	writel(devconf2, &am35x_scm_general_regs->devconf2);
40 
41 	/* wait until the USB phy is turned on */
42 	timeout = musb_cfg.timeout;
43 	while (timeout--)
44 		if (readl(&am35x_scm_general_regs->devconf2) & DEVCONF2_PHYCKGD)
45 			return 1;
46 
47 	/* USB phy was not turned on */
48 	return 0;
49 }
50 
51 /*
52  * Disable the USB phy
53  */
54 static void phy_off(void)
55 {
56 	u32 devconf2;
57 
58 	/*
59 	 * Power down the on-chip PHY.
60 	 */
61 	devconf2 = readl(&am35x_scm_general_regs->devconf2);
62 
63 	devconf2 &= ~DEVCONF2_PHY_PLLON;
64 	devconf2 |= DEVCONF2_PHYPWRDN | DEVCONF2_OTGPWRDN;
65 	writel(devconf2, &am35x_scm_general_regs->devconf2);
66 }
67 
68 /*
69  * This function performs platform specific initialization for usb0.
70  */
71 int musb_platform_init(void)
72 {
73 	u32 revision;
74 	u32 sw_reset;
75 
76 	/* global usb reset */
77 	sw_reset = readl(&am35x_scm_general_regs->ip_sw_reset);
78 	sw_reset |= (1 << 0);
79 	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
80 	sw_reset &= ~(1 << 0);
81 	writel(sw_reset, &am35x_scm_general_regs->ip_sw_reset);
82 
83 	/* reset the controller */
84 	writel(0x1, &am35x_usb_regs->control);
85 	udelay(5000);
86 
87 	/* start the on-chip usb phy and its pll */
88 	if (phy_on() == 0)
89 		return -1;
90 
91 	/* Returns zero if e.g. not clocked */
92 	revision = readl(&am35x_usb_regs->revision);
93 	if (revision == 0)
94 		return -1;
95 
96 	return 0;
97 }
98 
99 /*
100  * This function performs platform specific deinitialization for usb0.
101  */
102 void musb_platform_deinit(void)
103 {
104 	/* Turn off the phy */
105 	phy_off();
106 }
107 
108 /*
109  * This function reads data from endpoint fifo for AM35x
110  * which supports only 32bit read operation.
111  *
112  * ep           - endpoint number
113  * length       - number of bytes to read from FIFO
114  * fifo_data    - pointer to data buffer into which data is read
115  */
116 __attribute__((weak))
117 void read_fifo(u8 ep, u32 length, void *fifo_data)
118 {
119 	u8  *data = (u8 *)fifo_data;
120 	u32 val;
121 	int i;
122 
123 	/* select the endpoint index */
124 	writeb(ep, &musbr->index);
125 
126 	if (length > 4) {
127 		for (i = 0; i < (length >> 2); i++) {
128 			val = readl(&musbr->fifox[ep]);
129 			memcpy(data, &val, 4);
130 			data += 4;
131 		}
132 		length %= 4;
133 	}
134 	if (length > 0) {
135 		val = readl(&musbr->fifox[ep]);
136 		memcpy(data, &val, length);
137 	}
138 }
139