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