drivers/usb/dwc3/ulpi.c

   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/delay.h>
  11 #include <linux/time64.h>
  12 #include <linux/ulpi/regs.h>
  13
  14 #include "core.h"
  15 #include "io.h"
  16
  17 #define DWC3_ULPI_ADDR(a) \
  18                 ((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
  19                 DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
  20                 DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
  21
  22 #define DWC3_ULPI_BASE_DELAY    DIV_ROUND_UP(NSEC_PER_SEC, 60000000L)
  23
  24 static int dwc3_ulpi_busyloop(struct dwc3 *dwc, u8 addr, bool read)
  25 {
  26         unsigned long ns = 5L * DWC3_ULPI_BASE_DELAY;
  27         unsigned int count = 10000;
  28         u32 reg;
  29
  30         if (addr >= ULPI_EXT_VENDOR_SPECIFIC)
  31                 ns += DWC3_ULPI_BASE_DELAY;
  32
  33         if (read)
  34                 ns += DWC3_ULPI_BASE_DELAY;
  35
  36         reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
  37         if (reg & DWC3_GUSB2PHYCFG_SUSPHY)
  38                 usleep_range(1000, 1200);
  39
  40         while (count--) {
  41                 ndelay(ns);
  42                 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
  43                 if (reg & DWC3_GUSB2PHYACC_DONE)
  44                         return 0;
  45                 cpu_relax();
  46         }
  47
  48         return -ETIMEDOUT;
  49 }
  50
  51 static int dwc3_ulpi_read(struct device *dev, u8 addr)
  52 {
  53         struct dwc3 *dwc = dev_get_drvdata(dev);
  54         u32 reg;
  55         int ret;
  56
  57         reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
  58         dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
  59
  60         ret = dwc3_ulpi_busyloop(dwc, addr, true);
  61         if (ret)
  62                 return ret;
  63
  64         reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
  65
  66         return DWC3_GUSB2PHYACC_DATA(reg);
  67 }
  68
  69 static int dwc3_ulpi_write(struct device *dev, u8 addr, u8 val)
  70 {
  71         struct dwc3 *dwc = dev_get_drvdata(dev);
  72         u32 reg;
  73
  74         reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
  75         reg |= DWC3_GUSB2PHYACC_WRITE | val;
  76         dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
  77
  78         return dwc3_ulpi_busyloop(dwc, addr, false);
  79 }
  80
  81 static const struct ulpi_ops dwc3_ulpi_ops = {
  82         .read = dwc3_ulpi_read,
  83         .write = dwc3_ulpi_write,
  84 };
  85
  86 int dwc3_ulpi_init(struct dwc3 *dwc)
  87 {
  88         /* Register the interface */
  89         dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
  90         if (IS_ERR(dwc->ulpi)) {
  91                 dev_err(dwc->dev, "failed to register ULPI interface");
  92                 return PTR_ERR(dwc->ulpi);
  93         }
  94
  95         return 0;
  96 }
  97
  98 void dwc3_ulpi_exit(struct dwc3 *dwc)
  99 {
 100         if (dwc->ulpi) {
 101                 ulpi_unregister_interface(dwc->ulpi);
 102                 dwc->ulpi = NULL;
 103         }
 104 }