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 22 static 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 29 static 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 47 static 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 63 struct usb_phy_io_ops ulpi_viewport_access_ops = { 64 .read = ulpi_viewport_read, 65 .write = ulpi_viewport_write, 66 }; 67 EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops); 68