drivers/usb/dwc3/ulpi.c

   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
  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
  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
  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
  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
  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 }