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/*
* reset controller for CSR SiRFprimaII
*
* Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
*
* Licensed under GPLv2 or later.
*/
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/of_address.h>
void __iomem *sirfsoc_rstc_base;
static DEFINE_MUTEX(rstc_lock);
static struct of_device_id rstc_ids[] = {
{ .compatible = "sirf,prima2-rstc" },
};
static int __init sirfsoc_of_rstc_init(void)
{
struct device_node *np;
np = of_find_matching_node(NULL, rstc_ids);
if (!np)
panic("unable to find compatible rstc node in dtb\n");
sirfsoc_rstc_base = of_iomap(np, 0);
if (!sirfsoc_rstc_base)
panic("unable to map rstc cpu registers\n");
of_node_put(np);
return 0;
}
early_initcall(sirfsoc_of_rstc_init);
int sirfsoc_reset_device(struct device *dev)
{
const unsigned int *prop = of_get_property(dev->of_node, "reset-bit", NULL);
unsigned int reset_bit;
if (!prop)
return -ENODEV;
reset_bit = be32_to_cpup(prop);
mutex_lock(&rstc_lock);
/*
* Writing 1 to this bit resets corresponding block. Writing 0 to this
* bit de-asserts reset signal of the corresponding block.
* datasheet doesn't require explicit delay between the set and clear
* of reset bit. it could be shorter if tests pass.
*/
writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) | reset_bit,
sirfsoc_rstc_base + (reset_bit / 32) * 4);
msleep(10);
writel(readl(sirfsoc_rstc_base + (reset_bit / 32) * 4) & ~reset_bit,
sirfsoc_rstc_base + (reset_bit / 32) * 4);
mutex_unlock(&rstc_lock);
return 0;
}
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