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/kernel.h> 16 #include <linux/usb.h> 17 #include <linux/io.h> 18 #include <linux/usb/otg.h> 19 #include <linux/usb/ulpi.h> 20 21 #define ULPI_VIEW_WAKEUP (1 << 31) 22 #define ULPI_VIEW_RUN (1 << 30) 23 #define ULPI_VIEW_WRITE (1 << 29) 24 #define ULPI_VIEW_READ (0 << 29) 25 #define ULPI_VIEW_ADDR(x) (((x) & 0xff) << 16) 26 #define ULPI_VIEW_DATA_READ(x) (((x) >> 8) & 0xff) 27 #define ULPI_VIEW_DATA_WRITE(x) ((x) & 0xff) 28 29 static int ulpi_viewport_wait(void __iomem *view, u32 mask) 30 { 31 unsigned long usec = 2000; 32 33 while (usec--) { 34 if (!(readl(view) & mask)) 35 return 0; 36 37 udelay(1); 38 }; 39 40 return -ETIMEDOUT; 41 } 42 43 static int ulpi_viewport_read(struct usb_phy *otg, u32 reg) 44 { 45 int ret; 46 void __iomem *view = otg->io_priv; 47 48 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view); 49 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP); 50 if (ret) 51 return ret; 52 53 writel(ULPI_VIEW_RUN | ULPI_VIEW_READ | ULPI_VIEW_ADDR(reg), view); 54 ret = ulpi_viewport_wait(view, ULPI_VIEW_RUN); 55 if (ret) 56 return ret; 57 58 return ULPI_VIEW_DATA_READ(readl(view)); 59 } 60 61 static int ulpi_viewport_write(struct usb_phy *otg, u32 val, u32 reg) 62 { 63 int ret; 64 void __iomem *view = otg->io_priv; 65 66 writel(ULPI_VIEW_WAKEUP | ULPI_VIEW_WRITE, view); 67 ret = ulpi_viewport_wait(view, ULPI_VIEW_WAKEUP); 68 if (ret) 69 return ret; 70 71 writel(ULPI_VIEW_RUN | ULPI_VIEW_WRITE | ULPI_VIEW_DATA_WRITE(val) | 72 ULPI_VIEW_ADDR(reg), view); 73 74 return ulpi_viewport_wait(view, ULPI_VIEW_RUN); 75 } 76 77 struct usb_phy_io_ops ulpi_viewport_access_ops = { 78 .read = ulpi_viewport_read, 79 .write = ulpi_viewport_write, 80 }; 81