LXR linux/arch/powerpc/sysdev/fsl

   1/*
   2 * Freescale LBC and UPM routines.
   3 *
   4 * Copyright (c) 2007-2008  MontaVista Software, Inc.
   5 *
   6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 */
  13
  14#include <linux/init.h>
  15#include <linux/module.h>
  16#include <linux/kernel.h>
  17#include <linux/compiler.h>
  18#include <linux/spinlock.h>
  19#include <linux/types.h>
  20#include <linux/io.h>
  21#include <linux/of.h>
  22#include <asm/prom.h>
  23#include <asm/fsl_lbc.h>
  24
  25static spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
  26static struct fsl_lbc_regs __iomem *fsl_lbc_regs;
  27
  28static char __initdata *compat_lbc[] = {
  29        "fsl,pq2-localbus",
  30        "fsl,pq2pro-localbus",
  31        "fsl,pq3-localbus",
  32        "fsl,elbc",
  33};
  34
  35static int __init fsl_lbc_init(void)
  36{
  37        struct device_node *lbus;
  38        int i;
  39
  40        for (i = 0; i < ARRAY_SIZE(compat_lbc); i++) {
  41                lbus = of_find_compatible_node(NULL, NULL, compat_lbc[i]);
  42                if (lbus)
  43                        goto found;
  44        }
  45        return -ENODEV;
  46
  47found:
  48        fsl_lbc_regs = of_iomap(lbus, 0);
  49        of_node_put(lbus);
  50        if (!fsl_lbc_regs)
  51                return -ENOMEM;
  52        return 0;
  53}
  54arch_initcall(fsl_lbc_init);
  55
  56/**
  57 * fsl_lbc_find - find Localbus bank
  58 * @addr_base:  base address of the memory bank
  59 *
  60 * This function walks LBC banks comparing "Base address" field of the BR
  61 * registers with the supplied addr_base argument. When bases match this
  62 * function returns bank number (starting with 0), otherwise it returns
  63 * appropriate errno value.
  64 */
  65int fsl_lbc_find(phys_addr_t addr_base)
  66{
  67        int i;
  68
  69        if (!fsl_lbc_regs)
  70                return -ENODEV;
  71
  72        for (i = 0; i < ARRAY_SIZE(fsl_lbc_regs->bank); i++) {
  73                __be32 br = in_be32(&fsl_lbc_regs->bank[i].br);
  74                __be32 or = in_be32(&fsl_lbc_regs->bank[i].or);
  75
  76                if (br & BR_V && (br & or & BR_BA) == addr_base)
  77                        return i;
  78        }
  79
  80        return -ENOENT;
  81}
  82EXPORT_SYMBOL(fsl_lbc_find);
  83
  84/**
  85 * fsl_upm_find - find pre-programmed UPM via base address
  86 * @addr_base:  base address of the memory bank controlled by the UPM
  87 * @upm:        pointer to the allocated fsl_upm structure
  88 *
  89 * This function fills fsl_upm structure so you can use it with the rest of
  90 * UPM API. On success this function returns 0, otherwise it returns
  91 * appropriate errno value.
  92 */
  93int fsl_upm_find(phys_addr_t addr_base, struct fsl_upm *upm)
  94{
  95        int bank;
  96        __be32 br;
  97
  98        bank = fsl_lbc_find(addr_base);
  99        if (bank < 0)
 100                return bank;
 101
 102        br = in_be32(&fsl_lbc_regs->bank[bank].br);
 103
 104        switch (br & BR_MSEL) {
 105        case BR_MS_UPMA:
 106                upm->mxmr = &fsl_lbc_regs->mamr;
 107                break;
 108        case BR_MS_UPMB:
 109                upm->mxmr = &fsl_lbc_regs->mbmr;
 110                break;
 111        case BR_MS_UPMC:
 112                upm->mxmr = &fsl_lbc_regs->mcmr;
 113                break;
 114        default:
 115                return -EINVAL;
 116        }
 117
 118        switch (br & BR_PS) {
 119        case BR_PS_8:
 120                upm->width = 8;
 121                break;
 122        case BR_PS_16:
 123                upm->width = 16;
 124                break;
 125        case BR_PS_32:
 126                upm->width = 32;
 127                break;
 128        default:
 129                return -EINVAL;
 130        }
 131
 132        return 0;
 133}
 134EXPORT_SYMBOL(fsl_upm_find);
 135
 136/**
 137 * fsl_upm_run_pattern - actually run an UPM pattern
 138 * @upm:        pointer to the fsl_upm structure obtained via fsl_upm_find
 139 * @io_base:    remapped pointer to where memory access should happen
 140 * @mar:        MAR register content during pattern execution
 141 *
 142 * This function triggers dummy write to the memory specified by the io_base,
 143 * thus UPM pattern actually executed. Note that mar usage depends on the
 144 * pre-programmed AMX bits in the UPM RAM.
 145 */
 146int fsl_upm_run_pattern(struct fsl_upm *upm, void __iomem *io_base, u32 mar)
 147{
 148        int ret = 0;
 149        unsigned long flags;
 150
 151        spin_lock_irqsave(&fsl_lbc_lock, flags);
 152
 153        out_be32(&fsl_lbc_regs->mar, mar);
 154
 155        switch (upm->width) {
 156        case 8:
 157                out_8(io_base, 0x0);
 158                break;
 159        case 16:
 160                out_be16(io_base, 0x0);
 161                break;
 162        case 32:
 163                out_be32(io_base, 0x0);
 164                break;
 165        default:
 166                ret = -EINVAL;
 167                break;
 168        }
 169
 170        spin_unlock_irqrestore(&fsl_lbc_lock, flags);
 171
 172        return ret;
 173}
 174EXPORT_SYMBOL(fsl_upm_run_pattern);
 175