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
23static 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
38static int dwc3_ulpi_read(struct ulpi_ops *ops, u8 addr)
39{
40	struct dwc3 *dwc = dev_get_drvdata(ops->dev);
41	u32 reg;
42	int ret;
43
44	reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
45	dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
46
47	ret = dwc3_ulpi_busyloop(dwc);
48	if (ret)
49		return ret;
50
51	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
52
53	return DWC3_GUSB2PHYACC_DATA(reg);
54}
55
56static int dwc3_ulpi_write(struct ulpi_ops *ops, u8 addr, u8 val)
57{
58	struct dwc3 *dwc = dev_get_drvdata(ops->dev);
59	u32 reg;
60
61	reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
62	reg |= DWC3_GUSB2PHYACC_WRITE | val;
63	dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
64
65	return dwc3_ulpi_busyloop(dwc);
66}
67
68static struct ulpi_ops dwc3_ulpi_ops = {
69	.read = dwc3_ulpi_read,
70	.write = dwc3_ulpi_write,
71};
72
73int dwc3_ulpi_init(struct dwc3 *dwc)
74{
75	/* Register the interface */
76	dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
77	if (IS_ERR(dwc->ulpi)) {
78		dev_err(dwc->dev, "failed to register ULPI interface");
79		return PTR_ERR(dwc->ulpi);
80	}
81
82	return 0;
83}
84
85void dwc3_ulpi_exit(struct dwc3 *dwc)
86{
87	if (dwc->ulpi) {
88		ulpi_unregister_interface(dwc->ulpi);
89		dwc->ulpi = NULL;
90	}
91}
92