arch/powerpc/sysdev/fsl_lbc.c

   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
  25 static spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
  26 static struct fsl_lbc_regs __iomem *fsl_lbc_regs;
  27
  28 static char __initdata *compat_lbc[] = {
  29         "fsl,pq2-localbus",
  30         "fsl,pq2pro-localbus",
  31         "fsl,pq3-localbus",
  32         "fsl,elbc",
  33 };
  34
  35 static 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
  47 found:
  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 }
  54 arch_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  */
  65 int 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 }
  82 EXPORT_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  */
  93 int 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 }
 134 EXPORT_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  */
 146 int 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 }
 174 EXPORT_SYMBOL(fsl_upm_run_pattern);