LXR linux/drivers/usb/phy/phy-ulpi-viewport.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2011 Google, Inc.
   4 */
   5
   6#include <linux/export.h>
   7#include <linux/kernel.h>
   8#include <linux/usb.h>
   9#include <linux/io.h>
  10#include <linux/iopoll.h>
  11#include <linux/usb/otg.h>
  12#include <linux/usb/ulpi.h>
  13
  14#define ULPI_VIEW_WAKEUP        (1 << 31)
  15#define ULPI_VIEW_RUN           (1 << 30)
  16#define ULPI_VIEW_WRITE         (1 << 29)
  17#define ULPI_VIEW_READ          (0 << 29)
  18#define ULPI_VIEW_ADDR(x)       (((x) & 0xff) << 16)
  19#define ULPI_VIEW_DATA_READ(x)  (((x) >> 8) & 0xff)
  20#define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff)
  21
  22static int ulpi_viewport_wait(void __iomem *view, u32 mask)
  23{
  24        u32 val;
  25
  26        return readl_poll_timeout_atomic(view, val, !(val & mask), 1, 2000);
  27}
  28
  29static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
  30{
  31        int ret;
  32        void __iomem *view = otg->io_priv;
  33
  34        writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
  35        ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
  36        if (ret)
  37                return ret;
  38
  39        writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
  40        ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
  41        if (ret)
  42                return ret;
  43
  44        return ULPI_VIEW_DATA_READ(readl(view));
  45}
  46
  47static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
  48{
  49        int ret;
  50        void __iomem *view = otg->io_priv;
  51
  52        writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
  53        ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
  54        if (ret)
  55                return ret;
  56
  57        writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
  58                                                 ULPI_VIEW_ADDR(reg), view);
  59
  60        return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
  61}
  62
  63struct usb_phy_io_ops ulpi_viewport_access_ops = {
  64        .read   = ulpi_viewport_read,
  65        .write  = ulpi_viewport_write,
  66};
  67EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);
  68