linux/arch/c6x/platforms/emif.c

88 lines
2.0 KiB
C
Raw Normal View History

/*
* External Memory Interface
*
* Copyright (C) 2011 Texas Instruments Incorporated
* Author: Mark Salter <msalter@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <asm/soc.h>
#include <asm/dscr.h>
#define NUM_EMIFA_CHIP_ENABLES 4
struct emifa_regs {
u32 midr;
u32 stat;
u32 reserved1[6];
u32 bprio;
u32 reserved2[23];
u32 cecfg[NUM_EMIFA_CHIP_ENABLES];
u32 reserved3[4];
u32 awcc;
u32 reserved4[7];
u32 intraw;
u32 intmsk;
u32 intmskset;
u32 intmskclr;
};
static struct of_device_id emifa_match[] __initdata = {
{ .compatible = "ti,c64x+emifa" },
{}
};
/*
* Parse device tree for existence of an EMIF (External Memory Interface)
* and initialize it if found.
*/
static int __init c6x_emifa_init(void)
{
struct emifa_regs __iomem *regs;
struct device_node *node;
const __be32 *p;
u32 val;
int i, len, err;
node = of_find_matching_node(NULL, emifa_match);
if (!node)
return 0;
regs = of_iomap(node, 0);
if (!regs)
return 0;
/* look for a dscr-based enable for emifa pin buffers */
err = of_property_read_u32_array(node, "ti,dscr-dev-enable", &val, 1);
if (!err)
dscr_set_devstate(val, DSCR_DEVSTATE_ENABLED);
/* set up the chip enables */
p = of_get_property(node, "ti,emifa-ce-config", &len);
if (p) {
len /= sizeof(u32);
if (len > NUM_EMIFA_CHIP_ENABLES)
len = NUM_EMIFA_CHIP_ENABLES;
for (i = 0; i <= len; i++)
soc_writel(be32_to_cpup(&p[i]), &regs->cecfg[i]);
}
err = of_property_read_u32_array(node, "ti,emifa-burst-priority", &val, 1);
if (!err)
soc_writel(val, &regs->bprio);
err = of_property_read_u32_array(node, "ti,emifa-async-wait-control", &val, 1);
if (!err)
soc_writel(val, &regs->awcc);
iounmap(regs);
of_node_put(node);
return 0;
}
pure_initcall(c6x_emifa_init);