Logo Search packages:      
Sourcecode: linux version File versions  Download package

fsl_lbc.c

/*
 * Freescale LBC and UPM routines.
 *
 * Copyright (c) 2007-2008  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/of.h>
#include <asm/prom.h>
#include <asm/fsl_lbc.h>

static spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
static struct fsl_lbc_regs __iomem *fsl_lbc_regs;

static char __initdata *compat_lbc[] = {
      "fsl,pq2-localbus",
      "fsl,pq2pro-localbus",
      "fsl,pq3-localbus",
      "fsl,elbc",
};

static int __init fsl_lbc_init(void)
{
      struct device_node *lbus;
      int i;

      for (i = 0; i < ARRAY_SIZE(compat_lbc); i++) {
            lbus = of_find_compatible_node(NULL, NULL, compat_lbc[i]);
            if (lbus)
                  goto found;
      }
      return -ENODEV;

found:
      fsl_lbc_regs = of_iomap(lbus, 0);
      of_node_put(lbus);
      if (!fsl_lbc_regs)
            return -ENOMEM;
      return 0;
}
arch_initcall(fsl_lbc_init);

/**
 * fsl_lbc_find - find Localbus bank
 * @addr_base:    base address of the memory bank
 *
 * This function walks LBC banks comparing "Base address" field of the BR
 * registers with the supplied addr_base argument. When bases match this
 * function returns bank number (starting with 0), otherwise it returns
 * appropriate errno value.
 */
int fsl_lbc_find(phys_addr_t addr_base)
{
      int i;

      if (!fsl_lbc_regs)
            return -ENODEV;

      for (i = 0; i < ARRAY_SIZE(fsl_lbc_regs->bank); i++) {
            __be32 br = in_be32(&fsl_lbc_regs->bank[i].br);
            __be32 or = in_be32(&fsl_lbc_regs->bank[i].or);

            if (br & BR_V && (br & or & BR_BA) == addr_base)
                  return i;
      }

      return -ENOENT;
}
EXPORT_SYMBOL(fsl_lbc_find);

/**
 * fsl_upm_find - find pre-programmed UPM via base address
 * @addr_base:    base address of the memory bank controlled by the UPM
 * @upm:    pointer to the allocated fsl_upm structure
 *
 * This function fills fsl_upm structure so you can use it with the rest of
 * UPM API. On success this function returns 0, otherwise it returns
 * appropriate errno value.
 */
int fsl_upm_find(phys_addr_t addr_base, struct fsl_upm *upm)
{
      int bank;
      __be32 br;

      bank = fsl_lbc_find(addr_base);
      if (bank < 0)
            return bank;

      br = in_be32(&fsl_lbc_regs->bank[bank].br);

      switch (br & BR_MSEL) {
      case BR_MS_UPMA:
            upm->mxmr = &fsl_lbc_regs->mamr;
            break;
      case BR_MS_UPMB:
            upm->mxmr = &fsl_lbc_regs->mbmr;
            break;
      case BR_MS_UPMC:
            upm->mxmr = &fsl_lbc_regs->mcmr;
            break;
      default:
            return -EINVAL;
      }

      switch (br & BR_PS) {
      case BR_PS_8:
            upm->width = 8;
            break;
      case BR_PS_16:
            upm->width = 16;
            break;
      case BR_PS_32:
            upm->width = 32;
            break;
      default:
            return -EINVAL;
      }

      return 0;
}
EXPORT_SYMBOL(fsl_upm_find);

/**
 * fsl_upm_run_pattern - actually run an UPM pattern
 * @upm:    pointer to the fsl_upm structure obtained via fsl_upm_find
 * @io_base:      remapped pointer to where memory access should happen
 * @mar:    MAR register content during pattern execution
 *
 * This function triggers dummy write to the memory specified by the io_base,
 * thus UPM pattern actually executed. Note that mar usage depends on the
 * pre-programmed AMX bits in the UPM RAM.
 */
int fsl_upm_run_pattern(struct fsl_upm *upm, void __iomem *io_base, u32 mar)
{
      int ret = 0;
      unsigned long flags;

      spin_lock_irqsave(&fsl_lbc_lock, flags);

      out_be32(&fsl_lbc_regs->mar, mar << (32 - upm->width));

      switch (upm->width) {
      case 8:
            out_8(io_base, 0x0);
            break;
      case 16:
            out_be16(io_base, 0x0);
            break;
      case 32:
            out_be32(io_base, 0x0);
            break;
      default:
            ret = -EINVAL;
            break;
      }

      spin_unlock_irqrestore(&fsl_lbc_lock, flags);

      return ret;
}
EXPORT_SYMBOL(fsl_upm_run_pattern);

Generated by  Doxygen 1.6.0   Back to index