drivers/usb/ulpi/omap-ulpi-viewport.c

   1 /*
   2  * OMAP ulpi viewport support
   3  * Based on drivers/usb/ulpi/ulpi-viewport.c
   4  *
   5  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com
   6  * Author: Govindraj R <govindraj.raja@ti.com>
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0
   9  */
  10
  11 #include <common.h>
  12 #include <asm/io.h>
  13 #include <usb/ulpi.h>
  14
  15 #define OMAP_ULPI_WR_OPSEL      (2 << 22)
  16 #define OMAP_ULPI_RD_OPSEL      (3 << 22)
  17 #define OMAP_ULPI_START         (1 << 31)
  18
  19 /*
  20  * Wait for having ulpi in done state
  21  */
  22 static int ulpi_wait(struct ulpi_viewport *ulpi_vp, u32 mask)
  23 {
  24         int timeout = CONFIG_USB_ULPI_TIMEOUT;
  25
  26         while (--timeout) {
  27                 if (!(readl(ulpi_vp->viewport_addr) & mask))
  28                         return 0;
  29
  30                 udelay(1);
  31         }
  32
  33         return ULPI_ERROR;
  34 }
  35
  36 /*
  37  * Issue a ULPI read/write request
  38  */
  39 static int ulpi_request(struct ulpi_viewport *ulpi_vp, u32 value)
  40 {
  41         int err;
  42
  43         writel(value, ulpi_vp->viewport_addr);
  44
  45         err = ulpi_wait(ulpi_vp, OMAP_ULPI_START);
  46         if (err)
  47                 debug("ULPI request timed out\n");
  48
  49         return err;
  50 }
  51
  52 int ulpi_write(struct ulpi_viewport *ulpi_vp, u8 *reg, u32 value)
  53 {
  54         u32 val = OMAP_ULPI_START | (((ulpi_vp->port_num + 1) & 0xf) << 24) |
  55                         OMAP_ULPI_WR_OPSEL | ((u32)reg << 16) | (value & 0xff);
  56
  57         return ulpi_request(ulpi_vp, val);
  58 }
  59
  60 u32 ulpi_read(struct ulpi_viewport *ulpi_vp, u8 *reg)
  61 {
  62         int err;
  63         u32 val = OMAP_ULPI_START | (((ulpi_vp->port_num + 1) & 0xf) << 24) |
  64                          OMAP_ULPI_RD_OPSEL | ((u32)reg << 16);
  65
  66         err = ulpi_request(ulpi_vp, val);
  67         if (err)
  68                 return err;
  69
  70         return readl(ulpi_vp->viewport_addr) & 0xff;
  71 }