1 /**
2 * ulpi.c - DesignWare USB3 Controller's ULPI PHY interface
3 *
4 * Copyright (C) 2015 Intel Corporation
5 *
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.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 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/ulpi/regs.h>
14
15 #include "core.h"
16 #include "io.h"
17
18 #define DWC3_ULPI_ADDR(a) \
19 ((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
20 DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
21 DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
22
dwc3_ulpi_busyloop(struct dwc3 * dwc)23 static int dwc3_ulpi_busyloop(struct dwc3 *dwc)
24 {
25 unsigned count = 1000;
26 u32 reg;
27
28 while (count--) {
29 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
30 if (!(reg & DWC3_GUSB2PHYACC_BUSY))
31 return 0;
32 cpu_relax();
33 }
34
35 return -ETIMEDOUT;
36 }
37
dwc3_ulpi_read(struct device * dev,u8 addr)38 static int dwc3_ulpi_read(struct device *dev, u8 addr)
39 {
40 struct dwc3 *dwc = dev_get_drvdata(dev);
41 u32 reg;
42 int ret;
43
44 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
45 if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
46 reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
47 dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
48 }
49
50 reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
51 dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
52
53 ret = dwc3_ulpi_busyloop(dwc);
54 if (ret)
55 return ret;
56
57 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
58
59 return DWC3_GUSB2PHYACC_DATA(reg);
60 }
61
dwc3_ulpi_write(struct device * dev,u8 addr,u8 val)62 static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
63 {
64 struct dwc3 *dwc = dev_get_drvdata(dev);
65 u32 reg;
66
67 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
68 if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
69 reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
70 dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
71 }
72
73 reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
74 reg |= DWC3_GUSB2PHYACC_WRITE | val;
75 dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
76
77 return dwc3_ulpi_busyloop(dwc);
78 }
79
80 static const struct ulpi_ops dwc3_ulpi_ops = {
81 .read = dwc3_ulpi_read,
82 .write = dwc3_ulpi_write,
83 };
84
dwc3_ulpi_init(struct dwc3 * dwc)85 int dwc3_ulpi_init(struct dwc3 *dwc)
86 {
87 /* Register the interface */
88 dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
89 if (IS_ERR(dwc->ulpi)) {
90 dev_err(dwc->dev, "failed to register ULPI interface");
91 return PTR_ERR(dwc->ulpi);
92 }
93
94 return 0;
95 }
96
dwc3_ulpi_exit(struct dwc3 * dwc)97 void dwc3_ulpi_exit(struct dwc3 *dwc)
98 {
99 if (dwc->ulpi) {
100 ulpi_unregister_interface(dwc->ulpi);
101 dwc->ulpi = NULL;
102 }
103 }
104