1 /* 2 * Copyright (C) 2011 Google, Inc. 3 * 4 * This software is licensed under the terms of the GNU General Public 5 * License version 2, as published by the Free Software Foundation, and 6 * may be copied, distributed, and modified under those terms. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 */ 14 15 #include <linux/export.h> 16 #include <linux/kernel.h> 17 #include <linux/usb.h> 18 #include <linux/io.h> 19 #include <linux/usb/otg.h> 20 #include <linux/usb/ulpi.h> 21 22 #define ULPI_VIEW_WAKEUP (1 << 31) 23 #define ULPI_VIEW_RUN (1 << 30) 24 #define ULPI_VIEW_WRITE (1 << 29) 25 #define ULPI_VIEW_READ (0 << 29) 26 #define ULPI_VIEW_ADDR(x) (((x) & 0xff) << 16) 27 #define ULPI_VIEW_DATA_READ(x) (((x) >> 8) & 0xff) 28 #define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff) 29 30 static int ulpi_viewport_wait(void __iomem *view, u32 mask) 31 { 32 unsigned long usec = 2000; 33 34 while (usec--) { 35 if (!(readl(view) & mask)) 36 return 0; 37 38 udelay(1); 39 } 40 41 return -ETIMEDOUT; 42 } 43 44 static int ulpi_viewport_read(struct usb_phy *otg, u32 reg) 45 { 46 int ret; 47 void __iomem *view = otg->io_priv; 48 49 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view); 50 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP); 51 if (ret) 52 return ret; 53 54 writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view); 55 ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN); 56 if (ret) 57 return ret; 58 59 return ULPI_VIEW_DATA_READ(readl(view)); 60 } 61 62 static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg) 63 { 64 int ret; 65 void __iomem *view = otg->io_priv; 66 67 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view); 68 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP); 69 if (ret) 70 return ret; 71 72 writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) | 73 ULPI_VIEW_ADDR(reg), view); 74 75 return ulpi_viewport_wait(view, ULPI_VIEW_RUN); 76 } 77 78 struct usb_phy_io_ops ulpi_viewport_access_ops = { 79 .read = ulpi_viewport_read, 80 .write = ulpi_viewport_write, 81 }; 82 EXPORT_SYMBOL_GPL(ulpi_viewport_access_ops); 83