src/soc/intel/broadwell/iobp.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2014 Google Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <console/console.h>
  17 #include <delay.h>
  18 #include <arch/io.h>
  19 #include <soc/iobp.h>
  20 #include <soc/rcba.h>
  21
  22 #define IOBP_RETRY 1000
  23
  24 static inline int iobp_poll(void)
  25 {
  26         unsigned try;
  27
  28         for (try = IOBP_RETRY; try > 0; try--) {
  29                 u16 status = RCBA16(IOBPS);
  30                 if ((status & IOBPS_READY) == 0)
  31                         return 1;
  32                 udelay(10);
  33         }
  34
  35         printk(BIOS_ERR, "IOBP: timeout waiting for transaction to complete\n");
  36         return 0;
  37 }
  38
  39 u32 pch_iobp_read(u32 address)
  40 {
  41         u16 status;
  42
  43         if (!iobp_poll())
  44                 return 0;
  45
  46         /* Set the address */
  47         RCBA32(IOBPIRI) = address;
  48
  49         /* READ OPCODE */
  50         status = RCBA16(IOBPS);
  51         status &= ~IOBPS_MASK;
  52         status |= IOBPS_READ;
  53         RCBA16(IOBPS) = status;
  54
  55         /* Undocumented magic */
  56         RCBA16(IOBPU) = IOBPU_MAGIC;
  57
  58         /* Set ready bit */
  59         status = RCBA16(IOBPS);
  60         status |= IOBPS_READY;
  61         RCBA16(IOBPS) = status;
  62
  63         if (!iobp_poll())
  64                 return 0;
  65
  66         /* Check for successful transaction */
  67         status = RCBA16(IOBPS);
  68         if (status & IOBPS_TX_MASK) {
  69                 printk(BIOS_ERR, "IOBP: read 0x%08x failed\n", address);
  70                 return 0;
  71         }
  72
  73         /* Read IOBP data */
  74         return RCBA32(IOBPD);
  75 }
  76
  77 void pch_iobp_write(u32 address, u32 data)
  78 {
  79         u16 status;
  80
  81         if (!iobp_poll())
  82                 return;
  83
  84         /* Set the address */
  85         RCBA32(IOBPIRI) = address;
  86
  87         /* WRITE OPCODE */
  88         status = RCBA16(IOBPS);
  89         status &= ~IOBPS_MASK;
  90         status |= IOBPS_WRITE;
  91         RCBA16(IOBPS) = status;
  92
  93         RCBA32(IOBPD) = data;
  94
  95         /* Undocumented magic */
  96         RCBA16(IOBPU) = IOBPU_MAGIC;
  97
  98         /* Set ready bit */
  99         status = RCBA16(IOBPS);
 100         status |= IOBPS_READY;
 101         RCBA16(IOBPS) = status;
 102
 103         if (!iobp_poll())
 104                 return;
 105
 106         /* Check for successful transaction */
 107         status = RCBA16(IOBPS);
 108         if (status & IOBPS_TX_MASK)
 109                 printk(BIOS_ERR, "IOBP: write 0x%08x failed\n", address);
 110 }
 111
 112 void pch_iobp_update(u32 address, u32 andvalue, u32 orvalue)
 113 {
 114         u32 data = pch_iobp_read(address);
 115
 116         /* Update the data */
 117         data &= andvalue;
 118         data |= orvalue;
 119
 120         pch_iobp_write(address, data);
 121 }
 122
 123 void pch_iobp_exec(u32 addr, u16 op_code, u8 route_id, u32 *data, u8 *resp)
 124 {
 125         if (!data || !resp)
 126                 return;
 127
 128         *resp = -1;
 129         if (!iobp_poll())
 130                 return;
 131
 132         /* RCBA2330[31:0] = Address */
 133         RCBA32(IOBPIRI) = addr;
 134         /* RCBA2338[15:8] = opcode */
 135         RCBA16(IOBPS) = (RCBA16(IOBPS) & 0x00ff) | op_code;
 136         /* RCBA233A[15:8] = 0xf0 RCBA233A[7:0] = Route ID */
 137         RCBA16(IOBPU) = IOBPU_MAGIC | route_id;
 138
 139         RCBA32(IOBPD) = *data;
 140         /* Set RCBA2338[0] to trigger IOBP transaction*/
 141         RCBA16(IOBPS) = RCBA16(IOBPS) | 0x1;
 142
 143         if (!iobp_poll())
 144                 return;
 145
 146         *resp = (RCBA16(IOBPS) & IOBPS_TX_MASK) >> 1;
 147         *data = RCBA32(IOBPD);
 148 }