forked from Minki/linux
hwrng: picoxcell - remove unbuildable picoxcell TRNG
The driver for the "Picochip picoXcell true random number generator" was added in v2.6.39. Its Kconfig symbol has always depended on PICOXCELL_PC3X3. But that Kconfig symbol has never been part of the tree. This means this driver has never been buildable. Let's remove it. It can be re-added if its dependencies are actually part of the tree. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Acked-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Paul Bolle
Herbert Xu
parent
5347ee8eff
commit
8ece117104
@ -255,19 +255,6 @@ config HW_RANDOM_NOMADIK
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If unsure, say Y.
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config HW_RANDOM_PICOXCELL
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tristate "Picochip picoXcell true random number generator support"
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depends on ARCH_PICOXCELL && PICOXCELL_PC3X3
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default HW_RANDOM
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---help---
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This driver provides kernel-side support for the Random Number
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Generator hardware found on Picochip PC3x3 and later devices.
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To compile this driver as a module, choose M here: the
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module will be called picoxcell-rng.
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If unsure, say Y.
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config HW_RANDOM_PPC4XX
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tristate "PowerPC 4xx generic true random number generator support"
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depends on PPC && 4xx
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@ -22,7 +22,6 @@ obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
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obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
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obj-$(CONFIG_HW_RANDOM_OCTEON) += octeon-rng.o
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obj-$(CONFIG_HW_RANDOM_NOMADIK) += nomadik-rng.o
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obj-$(CONFIG_HW_RANDOM_PICOXCELL) += picoxcell-rng.o
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obj-$(CONFIG_HW_RANDOM_PPC4XX) += ppc4xx-rng.o
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obj-$(CONFIG_HW_RANDOM_PSERIES) += pseries-rng.o
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obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
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@ -1,181 +0,0 @@
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/*
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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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static 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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rng_base = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(rng_base))
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return PTR_ERR(rng_base);
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rng_clk = devm_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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return ret;
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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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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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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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