1 // SPDX-License-Identifier: GPL-2.0
2 /**
3 * ulpi.c - DesignWare USB3 Controller's ULPI PHY interface
4 *
5 * Copyright (C) 2015 Intel Corporation
6 *
7 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
8 */
9
10 #include <linux/ulpi/regs.h>
11
12 #include "core.h"
13 #include "io.h"
14
15 #define DWC3_ULPI_ADDR(a) \
16 ((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
17 DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
18 DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
19
dwc3_ulpi_busyloop(struct dwc3 * dwc)20 static int dwc3_ulpi_busyloop(struct dwc3 *dwc)
21 {
22 unsigned count = 1000;
23 u32 reg;
24
25 while (count--) {
26 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
27 if (!(reg & DWC3_GUSB2PHYACC_BUSY))
28 return 0;
29 cpu_relax();
30 }
31
32 return -ETIMEDOUT;
33 }
34
dwc3_ulpi_read(struct device * dev,u8 addr)35 static int dwc3_ulpi_read(struct device *dev, u8 addr)
36 {
37 struct dwc3 *dwc = dev_get_drvdata(dev);
38 u32 reg;
39 int ret;
40
41 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
42 if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
43 reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
44 dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
45 }
46
47 reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
48 dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
49
50 ret = dwc3_ulpi_busyloop(dwc);
51 if (ret)
52 return ret;
53
54 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
55
56 return DWC3_GUSB2PHYACC_DATA(reg);
57 }
58
dwc3_ulpi_write(struct device * dev,u8 addr,u8 val)59 static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
60 {
61 struct dwc3 *dwc = dev_get_drvdata(dev);
62 u32 reg;
63
64 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
65 if (reg & DWC3_GUSB2PHYCFG_SUSPHY) {
66 reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
67 dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
68 }
69
70 reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
71 reg |= DWC3_GUSB2PHYACC_WRITE | val;
72 dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
73
74 return dwc3_ulpi_busyloop(dwc);
75 }
76
77 static const struct ulpi_ops dwc3_ulpi_ops = {
78 .read = dwc3_ulpi_read,
79 .write = dwc3_ulpi_write,
80 };
81
dwc3_ulpi_init(struct dwc3 * dwc)82 int dwc3_ulpi_init(struct dwc3 *dwc)
83 {
84 /* Register the interface */
85 dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
86 if (IS_ERR(dwc->ulpi)) {
87 dev_err(dwc->dev, "failed to register ULPI interface");
88 return PTR_ERR(dwc->ulpi);
89 }
90
91 return 0;
92 }
93
dwc3_ulpi_exit(struct dwc3 * dwc)94 void dwc3_ulpi_exit(struct dwc3 *dwc)
95 {
96 if (dwc->ulpi) {
97 ulpi_unregister_interface(dwc->ulpi);
98 dwc->ulpi = NULL;
99 }
100 }
101
