usb/phy/phy-ulpi-viewport.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Copyright (C) 2011 Google, Inc.
0004  */
0005
0006 #include <linux/export.h>
0007 #include <linux/kernel.h>
0008 #include <linux/usb.h>
0009 #include <linux/io.h>
0010 #include <linux/iopoll.h>
0011 #include <linux/usb/otg.h>
0012 #include <linux/usb/ulpi.h>
0013
0014 #define ULPI_VIEW_WAKEUP    (1 << 31)
0015 #define ULPI_VIEW_RUN       (1 << 30)
0016 #define ULPI_VIEW_WRITE     (1 << 29)
0017 #define ULPI_VIEW_READ      (0 << 29)
0018 #define ULPI_VIEW_ADDR(x)   (((x) & 0xff) << 16)
0019 #define ULPI_VIEW_DATA_READ(x)  (((x) >> 8) & 0xff)
0020 #define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff)
0021
0022 static int ulpi_viewport_wait(void __iomem *view, u32 mask)
0023 {
0024     u32 val;
0025
0026     return readl_poll_timeout_atomic(view, val, !(val & mask), 1, 2000);
0027 }
0028
0029 static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
0030 {
0031     int ret;
0032     void __iomem *view = otg->io_priv;
0033
0034     writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
0035     ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
0036     if (ret)
0037         return ret;
0038
0039     writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view);
0040     ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN);
0041     if (ret)
0042         return ret;
0043
0044     return ULPI_VIEW_DATA_READ(readl(view));
0045 }
0046
0047 static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg)
0048 {
0049     int ret;
0050     void __iomem *view = otg->io_priv;
0051
0052     writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view);
0053     ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP);
0054     if (ret)
0055         return ret;
0056
0057     writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) |
0058                          ULPI_VIEW_ADDR(reg), view);
0059
0060     return ulpi_viewport_wait(view, ULPI_VIEW_RUN);
0061 }
0062
0063 struct usb_phy_io_ops ulpi_viewport_access_ops = {
0064     .read   = ulpi_viewport_read,
0065     .write  = ulpi_viewport_write,
0066 };
0067 EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops);