2 * ulpi.c - DesignWare USB3 Controller's ULPI PHY interface
4 * Copyright (C) 2015 Intel Corporation
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
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.
13 #include <linux/delay.h>
14 #include <linux/time64.h>
15 #include <linux/ulpi/regs.h>
20 #define DWC3_ULPI_ADDR(a) \
21 ((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
22 DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
23 DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
25 #define DWC3_ULPI_BASE_DELAY DIV_ROUND_UP(NSEC_PER_SEC, 60000000L)
27 static int dwc3_ulpi_busyloop(struct dwc3 *dwc, u8 addr, bool read)
29 unsigned long ns = 5L * DWC3_ULPI_BASE_DELAY;
30 unsigned int count = 1000;
33 if (addr >= ULPI_EXT_VENDOR_SPECIFIC)
34 ns += DWC3_ULPI_BASE_DELAY;
37 ns += DWC3_ULPI_BASE_DELAY;
41 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
42 if (!(reg & DWC3_GUSB2PHYACC_BUSY))
50 static int dwc3_ulpi_read(struct device *dev, u8 addr)
52 struct dwc3 *dwc = dev_get_drvdata(dev);
56 reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
57 dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
59 ret = dwc3_ulpi_busyloop(dwc, addr, true);
63 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
65 return DWC3_GUSB2PHYACC_DATA(reg);
68 static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
70 struct dwc3 *dwc = dev_get_drvdata(dev);
73 reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
74 reg |= DWC3_GUSB2PHYACC_WRITE | val;
75 dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
77 return dwc3_ulpi_busyloop(dwc, addr, false);
80 static const struct ulpi_ops dwc3_ulpi_ops = {
81 .read = dwc3_ulpi_read,
82 .write = dwc3_ulpi_write,
85 int dwc3_ulpi_init(struct dwc3 *dwc)
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);
97 void dwc3_ulpi_exit(struct dwc3 *dwc)
100 ulpi_unregister_interface(dwc->ulpi);