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/kernel.h>
  15 #include <linux/of.h>
  16 #include <asm/fsl_lbc.h>
  17
  18 spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
  19
  20 struct fsl_lbc_regs __iomem *fsl_lbc_regs;
  21 EXPORT_SYMBOL(fsl_lbc_regs);
  22
  23 static char __initdata *compat_lbc[] = {
  24         "fsl,pq2-localbus",
  25         "fsl,pq2pro-localbus",
  26         "fsl,pq3-localbus",
  27         "fsl,elbc",
  28 };
  29
  30 static int __init fsl_lbc_init(void)
  31 {
  32         struct device_node *lbus;
  33         int i;
  34
  35         for (i = 0; i < ARRAY_SIZE(compat_lbc); i++) {
  36                 lbus = of_find_compatible_node(NULL, NULL, compat_lbc[i]);
  37                 if (lbus)
  38                         goto found;
  39         }
  40         return -ENODEV;
  41
  42 found:
  43         fsl_lbc_regs = of_iomap(lbus, 0);
  44         of_node_put(lbus);
  45         if (!fsl_lbc_regs)
  46                 return -ENOMEM;
  47         return 0;
  48 }
  49 arch_initcall(fsl_lbc_init);
  50
  51 /**
  52  * fsl_lbc_find - find Localbus bank
  53  * @addr_base:  base address of the memory bank
  54  *
  55  * This function walks LBC banks comparing "Base address" field of the BR
  56  * registers with the supplied addr_base argument. When bases match this
  57  * function returns bank number (starting with 0), otherwise it returns
  58  * appropriate errno value.
  59  */
  60 int fsl_lbc_find(phys_addr_t addr_base)
  61 {
  62         int i;
  63
  64         if (!fsl_lbc_regs)
  65                 return -ENODEV;
  66
  67         for (i = 0; i < ARRAY_SIZE(fsl_lbc_regs->bank); i++) {
  68                 __be32 br = in_be32(&fsl_lbc_regs->bank[i].br);
  69                 __be32 or = in_be32(&fsl_lbc_regs->bank[i].or);
  70
  71                 if (br & BR_V && (br & or & BR_BA) == addr_base)
  72                         return i;
  73         }
  74
  75         return -ENOENT;
  76 }
  77 EXPORT_SYMBOL(fsl_lbc_find);
  78
  79 /**
  80  * fsl_upm_find - find pre-programmed UPM via base address
  81  * @addr_base:  base address of the memory bank controlled by the UPM
  82  * @upm:        pointer to the allocated fsl_upm structure
  83  *
  84  * This function fills fsl_upm structure so you can use it with the rest of
  85  * UPM API. On success this function returns 0, otherwise it returns
  86  * appropriate errno value.
  87  */
  88 int fsl_upm_find(phys_addr_t addr_base, struct fsl_upm *upm)
  89 {
  90         int bank;
  91         __be32 br;
  92
  93         bank = fsl_lbc_find(addr_base);
  94         if (bank < 0)
  95                 return bank;
  96
  97         br = in_be32(&fsl_lbc_regs->bank[bank].br);
  98
  99         switch (br & BR_MSEL) {
 100         case BR_MS_UPMA:
 101                 upm->mxmr = &fsl_lbc_regs->mamr;
 102                 break;
 103         case BR_MS_UPMB:
 104                 upm->mxmr = &fsl_lbc_regs->mbmr;
 105                 break;
 106         case BR_MS_UPMC:
 107                 upm->mxmr = &fsl_lbc_regs->mcmr;
 108                 break;
 109         default:
 110                 return -EINVAL;
 111         }
 112
 113         switch (br & BR_PS) {
 114         case BR_PS_8:
 115                 upm->width = 8;
 116                 break;
 117         case BR_PS_16:
 118                 upm->width = 16;
 119                 break;
 120         case BR_PS_32:
 121                 upm->width = 32;
 122                 break;
 123         default:
 124                 return -EINVAL;
 125         }
 126
 127         return 0;
 128 }
 129 EXPORT_SYMBOL(fsl_upm_find);