WSL2-Linux-Kernel/arch/powerpc/sysdev/fsl_lbc.c

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3.9 KiB
C
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/*
* 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);
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);