![Greg Kroah-Hartman](/assets/img/avatar_default.png)
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: David Airlie <airlied@linux.ie> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
199 lines
4.7 KiB
C
199 lines
4.7 KiB
C
/*
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* Copyright (c) 2010-2011 Picochip Ltd., Jamie Iles
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* All enquiries to support@picochip.com
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*/
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#include <linux/clk.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/hw_random.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#define DATA_REG_OFFSET 0x0200
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#define CSR_REG_OFFSET 0x0278
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#define CSR_OUT_EMPTY_MASK (1 << 24)
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#define CSR_FAULT_MASK (1 << 1)
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#define TRNG_BLOCK_RESET_MASK (1 << 0)
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#define TAI_REG_OFFSET 0x0380
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/*
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* The maximum amount of time in microseconds to spend waiting for data if the
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* core wants us to wait. The TRNG should generate 32 bits every 320ns so a
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* timeout of 20us seems reasonable. The TRNG does builtin tests of the data
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* for randomness so we can't always assume there is data present.
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*/
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#define PICO_TRNG_TIMEOUT 20
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static void __iomem *rng_base;
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static struct clk *rng_clk;
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struct device *rng_dev;
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static inline u32 picoxcell_trng_read_csr(void)
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{
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return __raw_readl(rng_base + CSR_REG_OFFSET);
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}
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static inline bool picoxcell_trng_is_empty(void)
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{
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return picoxcell_trng_read_csr() & CSR_OUT_EMPTY_MASK;
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}
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/*
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* Take the random number generator out of reset and make sure the interrupts
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* are masked. We shouldn't need to get large amounts of random bytes so just
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* poll the status register. The hardware generates 32 bits every 320ns so we
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* shouldn't have to wait long enough to warrant waiting for an IRQ.
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*/
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static void picoxcell_trng_start(void)
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{
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__raw_writel(0, rng_base + TAI_REG_OFFSET);
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__raw_writel(0, rng_base + CSR_REG_OFFSET);
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}
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static void picoxcell_trng_reset(void)
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{
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__raw_writel(TRNG_BLOCK_RESET_MASK, rng_base + CSR_REG_OFFSET);
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__raw_writel(TRNG_BLOCK_RESET_MASK, rng_base + TAI_REG_OFFSET);
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picoxcell_trng_start();
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}
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/*
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* Get some random data from the random number generator. The hw_random core
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* layer provides us with locking.
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*/
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static int picoxcell_trng_read(struct hwrng *rng, void *buf, size_t max,
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bool wait)
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{
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int i;
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/* Wait for some data to become available. */
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for (i = 0; i < PICO_TRNG_TIMEOUT && picoxcell_trng_is_empty(); ++i) {
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if (!wait)
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return 0;
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udelay(1);
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}
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if (picoxcell_trng_read_csr() & CSR_FAULT_MASK) {
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dev_err(rng_dev, "fault detected, resetting TRNG\n");
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picoxcell_trng_reset();
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return -EIO;
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}
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if (i == PICO_TRNG_TIMEOUT)
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return 0;
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*(u32 *)buf = __raw_readl(rng_base + DATA_REG_OFFSET);
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return sizeof(u32);
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}
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static struct hwrng picoxcell_trng = {
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.name = "picoxcell",
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.read = picoxcell_trng_read,
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};
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static int picoxcell_trng_probe(struct platform_device *pdev)
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{
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int ret;
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struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!mem) {
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dev_warn(&pdev->dev, "no memory resource\n");
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return -ENOMEM;
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}
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if (!devm_request_mem_region(&pdev->dev, mem->start, resource_size(mem),
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"picoxcell_trng")) {
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dev_warn(&pdev->dev, "unable to request io mem\n");
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return -EBUSY;
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}
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rng_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
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if (!rng_base) {
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dev_warn(&pdev->dev, "unable to remap io mem\n");
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return -ENOMEM;
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}
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rng_clk = clk_get(&pdev->dev, NULL);
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if (IS_ERR(rng_clk)) {
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dev_warn(&pdev->dev, "no clk\n");
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return PTR_ERR(rng_clk);
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}
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ret = clk_enable(rng_clk);
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if (ret) {
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dev_warn(&pdev->dev, "unable to enable clk\n");
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goto err_enable;
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}
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picoxcell_trng_start();
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ret = hwrng_register(&picoxcell_trng);
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if (ret)
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goto err_register;
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rng_dev = &pdev->dev;
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dev_info(&pdev->dev, "pixoxcell random number generator active\n");
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return 0;
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err_register:
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clk_disable(rng_clk);
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err_enable:
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clk_put(rng_clk);
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return ret;
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}
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static int picoxcell_trng_remove(struct platform_device *pdev)
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{
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hwrng_unregister(&picoxcell_trng);
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clk_disable(rng_clk);
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clk_put(rng_clk);
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return 0;
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}
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#ifdef CONFIG_PM
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static int picoxcell_trng_suspend(struct device *dev)
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{
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clk_disable(rng_clk);
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return 0;
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}
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static int picoxcell_trng_resume(struct device *dev)
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{
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return clk_enable(rng_clk);
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}
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static const struct dev_pm_ops picoxcell_trng_pm_ops = {
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.suspend = picoxcell_trng_suspend,
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.resume = picoxcell_trng_resume,
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};
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#endif /* CONFIG_PM */
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static struct platform_driver picoxcell_trng_driver = {
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.probe = picoxcell_trng_probe,
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.remove = picoxcell_trng_remove,
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.driver = {
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.name = "picoxcell-trng",
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.owner = THIS_MODULE,
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#ifdef CONFIG_PM
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.pm = &picoxcell_trng_pm_ops,
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#endif /* CONFIG_PM */
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},
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};
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module_platform_driver(picoxcell_trng_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Jamie Iles");
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MODULE_DESCRIPTION("Picochip picoXcell TRNG driver");
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