diff options
Diffstat (limited to 'drivers/char/hw_random')
| -rw-r--r-- | drivers/char/hw_random/Kconfig | 24 | ||||
| -rw-r--r-- | drivers/char/hw_random/Makefile | 2 | ||||
| -rw-r--r-- | drivers/char/hw_random/core.c | 2 | ||||
| -rw-r--r-- | drivers/char/hw_random/exynos-rng.c | 58 | ||||
| -rw-r--r-- | drivers/char/hw_random/mxc-rnga.c | 14 | ||||
| -rw-r--r-- | drivers/char/hw_random/octeon-rng.c | 12 | ||||
| -rw-r--r-- | drivers/char/hw_random/pasemi-rng.c | 1 | ||||
| -rw-r--r-- | drivers/char/hw_random/ppc4xx-rng.c | 1 | ||||
| -rw-r--r-- | drivers/char/hw_random/st-rng.c | 151 | ||||
| -rw-r--r-- | drivers/char/hw_random/stm32-rng.c | 202 |
10 files changed, 435 insertions, 32 deletions
diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index f48cf11c6..dbf227194 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -10,7 +10,7 @@ menuconfig HW_RANDOM To compile this driver as a module, choose M here: the module will be called rng-core. This provides a device - that's usually called /dev/hw_random, and which exposes one + that's usually called /dev/hwrng, and which exposes one of possibly several hardware random number generators. These hardware random number generators do not feed directly @@ -346,6 +346,16 @@ config HW_RANDOM_MSM If unsure, say Y. +config HW_RANDOM_ST + tristate "ST Microelectronics HW Random Number Generator support" + depends on HW_RANDOM && ARCH_STI + ---help--- + This driver provides kernel-side support for the Random Number + Generator hardware found on STi series of SoCs. + + To compile this driver as a module, choose M here: the + module will be called st-rng. + config HW_RANDOM_XGENE tristate "APM X-Gene True Random Number Generator (TRNG) support" depends on HW_RANDOM && ARCH_XGENE @@ -359,6 +369,18 @@ config HW_RANDOM_XGENE If unsure, say Y. +config HW_RANDOM_STM32 + tristate "STMicroelectronics STM32 random number generator" + depends on HW_RANDOM && (ARCH_STM32 || COMPILE_TEST) + help + This driver provides kernel-side support for the Random Number + Generator hardware found on STM32 microcontrollers. + + To compile this driver as a module, choose M here: the + module will be called stm32-rng. + + If unsure, say N. + endif # HW_RANDOM config UML_RANDOM diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 055bb0151..5ad397635 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -30,4 +30,6 @@ obj-$(CONFIG_HW_RANDOM_TPM) += tpm-rng.o obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o obj-$(CONFIG_HW_RANDOM_MSM) += msm-rng.o +obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o +obj-$(CONFIG_HW_RANDOM_STM32) += stm32-rng.o diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 5643b65ce..6f497aa1b 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -323,7 +323,7 @@ static ssize_t hwrng_attr_current_store(struct device *dev, return -ERESTARTSYS; err = -ENODEV; list_for_each_entry(rng, &rng_list, list) { - if (strcmp(rng->name, buf) == 0) { + if (sysfs_streq(rng->name, buf)) { err = 0; if (rng != current_rng) err = set_current_rng(rng); diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c index dc4701fd8..30cf46231 100644 --- a/drivers/char/hw_random/exynos-rng.c +++ b/drivers/char/hw_random/exynos-rng.c @@ -53,15 +53,11 @@ static void exynos_rng_writel(struct exynos_rng *rng, u32 val, u32 offset) __raw_writel(val, rng->mem + offset); } -static int exynos_init(struct hwrng *rng) +static int exynos_rng_configure(struct exynos_rng *exynos_rng) { - struct exynos_rng *exynos_rng = container_of(rng, - struct exynos_rng, rng); int i; int ret = 0; - pm_runtime_get_sync(exynos_rng->dev); - for (i = 0 ; i < 5 ; i++) exynos_rng_writel(exynos_rng, jiffies, EXYNOS_PRNG_SEED_OFFSET + 4*i); @@ -70,6 +66,17 @@ static int exynos_init(struct hwrng *rng) & SEED_SETTING_DONE)) ret = -EIO; + return ret; +} + +static int exynos_init(struct hwrng *rng) +{ + struct exynos_rng *exynos_rng = container_of(rng, + struct exynos_rng, rng); + int ret = 0; + + pm_runtime_get_sync(exynos_rng->dev); + ret = exynos_rng_configure(exynos_rng); pm_runtime_put_noidle(exynos_rng->dev); return ret; @@ -81,21 +88,24 @@ static int exynos_read(struct hwrng *rng, void *buf, struct exynos_rng *exynos_rng = container_of(rng, struct exynos_rng, rng); u32 *data = buf; + int retry = 100; pm_runtime_get_sync(exynos_rng->dev); exynos_rng_writel(exynos_rng, PRNG_START, 0); while (!(exynos_rng_readl(exynos_rng, - EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE)) + EXYNOS_PRNG_STATUS_OFFSET) & PRNG_DONE) && --retry) cpu_relax(); + if (!retry) + return -ETIMEDOUT; exynos_rng_writel(exynos_rng, PRNG_DONE, EXYNOS_PRNG_STATUS_OFFSET); *data = exynos_rng_readl(exynos_rng, EXYNOS_PRNG_OUT1_OFFSET); pm_runtime_mark_last_busy(exynos_rng->dev); - pm_runtime_autosuspend(exynos_rng->dev); + pm_runtime_put_sync_autosuspend(exynos_rng->dev); return 4; } @@ -152,15 +162,45 @@ static int exynos_rng_runtime_resume(struct device *dev) return clk_prepare_enable(exynos_rng->clk); } + +static int exynos_rng_suspend(struct device *dev) +{ + return pm_runtime_force_suspend(dev); +} + +static int exynos_rng_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct exynos_rng *exynos_rng = platform_get_drvdata(pdev); + int ret; + + ret = pm_runtime_force_resume(dev); + if (ret) + return ret; + + return exynos_rng_configure(exynos_rng); +} #endif -static UNIVERSAL_DEV_PM_OPS(exynos_rng_pm_ops, exynos_rng_runtime_suspend, - exynos_rng_runtime_resume, NULL); +static const struct dev_pm_ops exynos_rng_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(exynos_rng_suspend, exynos_rng_resume) + SET_RUNTIME_PM_OPS(exynos_rng_runtime_suspend, + exynos_rng_runtime_resume, NULL) +}; + +static const struct of_device_id exynos_rng_dt_match[] = { + { + .compatible = "samsung,exynos4-rng", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, exynos_rng_dt_match); static struct platform_driver exynos_rng_driver = { .driver = { .name = "exynos-rng", .pm = &exynos_rng_pm_ops, + .of_match_table = exynos_rng_dt_match, }, .probe = exynos_rng_probe, }; diff --git a/drivers/char/hw_random/mxc-rnga.c b/drivers/char/hw_random/mxc-rnga.c index 6cbb72ec6..467362262 100644 --- a/drivers/char/hw_random/mxc-rnga.c +++ b/drivers/char/hw_random/mxc-rnga.c @@ -141,12 +141,11 @@ static void mxc_rnga_cleanup(struct hwrng *rng) static int __init mxc_rnga_probe(struct platform_device *pdev) { - int err = -ENODEV; + int err; struct resource *res; struct mxc_rng *mxc_rng; - mxc_rng = devm_kzalloc(&pdev->dev, sizeof(struct mxc_rng), - GFP_KERNEL); + mxc_rng = devm_kzalloc(&pdev->dev, sizeof(*mxc_rng), GFP_KERNEL); if (!mxc_rng) return -ENOMEM; @@ -160,13 +159,12 @@ static int __init mxc_rnga_probe(struct platform_device *pdev) mxc_rng->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(mxc_rng->clk)) { dev_err(&pdev->dev, "Could not get rng_clk!\n"); - err = PTR_ERR(mxc_rng->clk); - goto out; + return PTR_ERR(mxc_rng->clk); } err = clk_prepare_enable(mxc_rng->clk); if (err) - goto out; + return err; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mxc_rng->mem = devm_ioremap_resource(&pdev->dev, res); @@ -181,14 +179,10 @@ static int __init mxc_rnga_probe(struct platform_device *pdev) goto err_ioremap; } - dev_info(&pdev->dev, "MXC RNGA Registered.\n"); - return 0; err_ioremap: clk_disable_unprepare(mxc_rng->clk); - -out: return err; } diff --git a/drivers/char/hw_random/octeon-rng.c b/drivers/char/hw_random/octeon-rng.c index 6234a4a19..8c78aa090 100644 --- a/drivers/char/hw_random/octeon-rng.c +++ b/drivers/char/hw_random/octeon-rng.c @@ -96,7 +96,7 @@ static int octeon_rng_probe(struct platform_device *pdev) rng->ops = ops; platform_set_drvdata(pdev, &rng->ops); - ret = hwrng_register(&rng->ops); + ret = devm_hwrng_register(&pdev->dev, &rng->ops); if (ret) return -ENOENT; @@ -105,21 +105,11 @@ static int octeon_rng_probe(struct platform_device *pdev) return 0; } -static int octeon_rng_remove(struct platform_device *pdev) -{ - struct hwrng *rng = platform_get_drvdata(pdev); - - hwrng_unregister(rng); - - return 0; -} - static struct platform_driver octeon_rng_driver = { .driver = { .name = "octeon_rng", }, .probe = octeon_rng_probe, - .remove = octeon_rng_remove, }; module_platform_driver(octeon_rng_driver); diff --git a/drivers/char/hw_random/pasemi-rng.c b/drivers/char/hw_random/pasemi-rng.c index 51cb1d5cc..699b7259f 100644 --- a/drivers/char/hw_random/pasemi-rng.c +++ b/drivers/char/hw_random/pasemi-rng.c @@ -138,6 +138,7 @@ static const struct of_device_id rng_match[] = { { .compatible = "pasemi,pwrficient-rng", }, { }, }; +MODULE_DEVICE_TABLE(of, rng_match); static struct platform_driver rng_driver = { .driver = { diff --git a/drivers/char/hw_random/ppc4xx-rng.c b/drivers/char/hw_random/ppc4xx-rng.c index b2cfda0fa..c0db4387d 100644 --- a/drivers/char/hw_random/ppc4xx-rng.c +++ b/drivers/char/hw_random/ppc4xx-rng.c @@ -129,6 +129,7 @@ static const struct of_device_id ppc4xx_rng_match[] = { { .compatible = "amcc,ppc440epx-rng", }, {}, }; +MODULE_DEVICE_TABLE(of, ppc4xx_rng_match); static struct platform_driver ppc4xx_rng_driver = { .driver = { diff --git a/drivers/char/hw_random/st-rng.c b/drivers/char/hw_random/st-rng.c new file mode 100644 index 000000000..1d35363d2 --- /dev/null +++ b/drivers/char/hw_random/st-rng.c @@ -0,0 +1,151 @@ +/* + * ST Random Number Generator Driver ST's Platforms + * + * Author: Pankaj Dev: <pankaj.dev@st.com> + * Lee Jones <lee.jones@linaro.org> + * + * Copyright (C) 2015 STMicroelectronics (R&D) Limited + * + * 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/clk.h> +#include <linux/delay.h> +#include <linux/hw_random.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +/* Registers */ +#define ST_RNG_STATUS_REG 0x20 +#define ST_RNG_DATA_REG 0x24 + +/* Registers fields */ +#define ST_RNG_STATUS_BAD_SEQUENCE BIT(0) +#define ST_RNG_STATUS_BAD_ALTERNANCE BIT(1) +#define ST_RNG_STATUS_FIFO_FULL BIT(5) + +#define ST_RNG_SAMPLE_SIZE 2 /* 2 Byte (16bit) samples */ +#define ST_RNG_FIFO_DEPTH 4 +#define ST_RNG_FIFO_SIZE (ST_RNG_FIFO_DEPTH * ST_RNG_SAMPLE_SIZE) + +/* + * Samples are documented to be available every 0.667us, so in theory + * the 4 sample deep FIFO should take 2.668us to fill. However, during + * thorough testing, it became apparent that filling the FIFO actually + * takes closer to 12us. We then multiply by 2 in order to account for + * the lack of udelay()'s reliability, suggested by Russell King. + */ +#define ST_RNG_FILL_FIFO_TIMEOUT (12 * 2) + +struct st_rng_data { + void __iomem *base; + struct clk *clk; + struct hwrng ops; +}; + +static int st_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct st_rng_data *ddata = (struct st_rng_data *)rng->priv; + u32 status; + int i; + + if (max < sizeof(u16)) + return -EINVAL; + + /* Wait until FIFO is full - max 4uS*/ + for (i = 0; i < ST_RNG_FILL_FIFO_TIMEOUT; i++) { + status = readl_relaxed(ddata->base + ST_RNG_STATUS_REG); + if (status & ST_RNG_STATUS_FIFO_FULL) + break; + udelay(1); + } + + if (i == ST_RNG_FILL_FIFO_TIMEOUT) + return 0; + + for (i = 0; i < ST_RNG_FIFO_SIZE && i < max; i += 2) + *(u16 *)(data + i) = + readl_relaxed(ddata->base + ST_RNG_DATA_REG); + + return i; /* No of bytes read */ +} + +static int st_rng_probe(struct platform_device *pdev) +{ + struct st_rng_data *ddata; + struct resource *res; + struct clk *clk; + void __iomem *base; + int ret; + + ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + ret = clk_prepare_enable(clk); + if (ret) + return ret; + + ddata->ops.priv = (unsigned long)ddata; + ddata->ops.read = st_rng_read; + ddata->ops.name = pdev->name; + ddata->base = base; + ddata->clk = clk; + + dev_set_drvdata(&pdev->dev, ddata); + + ret = hwrng_register(&ddata->ops); + if (ret) { + dev_err(&pdev->dev, "Failed to register HW RNG\n"); + return ret; + } + + dev_info(&pdev->dev, "Successfully registered HW RNG\n"); + + return 0; +} + +static int st_rng_remove(struct platform_device *pdev) +{ + struct st_rng_data *ddata = dev_get_drvdata(&pdev->dev); + + hwrng_unregister(&ddata->ops); + + clk_disable_unprepare(ddata->clk); + + return 0; +} + +static const struct of_device_id st_rng_match[] = { + { .compatible = "st,rng" }, + {}, +}; +MODULE_DEVICE_TABLE(of, st_rng_match); + +static struct platform_driver st_rng_driver = { + .driver = { + .name = "st-hwrandom", + .of_match_table = of_match_ptr(st_rng_match), + }, + .probe = st_rng_probe, + .remove = st_rng_remove +}; + +module_platform_driver(st_rng_driver); + +MODULE_AUTHOR("Pankaj Dev <pankaj.dev@st.com>"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c new file mode 100644 index 000000000..92a810648 --- /dev/null +++ b/drivers/char/hw_random/stm32-rng.c @@ -0,0 +1,202 @@ +/* + * Copyright (c) 2015, Daniel Thompson + * + * This file is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This file is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/hw_random.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> + +#define RNG_CR 0x00 +#define RNG_CR_RNGEN BIT(2) + +#define RNG_SR 0x04 +#define RNG_SR_SEIS BIT(6) +#define RNG_SR_CEIS BIT(5) +#define RNG_SR_DRDY BIT(0) + +#define RNG_DR 0x08 + +/* + * It takes 40 cycles @ 48MHz to generate each random number (e.g. <1us). + * At the time of writing STM32 parts max out at ~200MHz meaning a timeout + * of 500 leaves us a very comfortable margin for error. The loop to which + * the timeout applies takes at least 4 instructions per iteration so the + * timeout is enough to take us up to multi-GHz parts! + */ +#define RNG_TIMEOUT 500 + +struct stm32_rng_private { + struct hwrng rng; + void __iomem *base; + struct clk *clk; +}; + +static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + struct stm32_rng_private *priv = + container_of(rng, struct stm32_rng_private, rng); + u32 sr; + int retval = 0; + + pm_runtime_get_sync((struct device *) priv->rng.priv); + + while (max > sizeof(u32)) { + sr = readl_relaxed(priv->base + RNG_SR); + if (!sr && wait) { + unsigned int timeout = RNG_TIMEOUT; + + do { + cpu_relax(); + sr = readl_relaxed(priv->base + RNG_SR); + } while (!sr && --timeout); + } + + /* If error detected or data not ready... */ + if (sr != RNG_SR_DRDY) + break; + + *(u32 *)data = readl_relaxed(priv->base + RNG_DR); + + retval += sizeof(u32); + data += sizeof(u32); + max -= sizeof(u32); + } + + if (WARN_ONCE(sr & (RNG_SR_SEIS | RNG_SR_CEIS), + "bad RNG status - %x\n", sr)) + writel_relaxed(0, priv->base + RNG_SR); + + pm_runtime_mark_last_busy((struct device *) priv->rng.priv); + pm_runtime_put_sync_autosuspend((struct device *) priv->rng.priv); + + return retval || !wait ? retval : -EIO; +} + +static int stm32_rng_init(struct hwrng *rng) +{ + struct stm32_rng_private *priv = + container_of(rng, struct stm32_rng_private, rng); + int err; + + err = clk_prepare_enable(priv->clk); + if (err) + return err; + + writel_relaxed(RNG_CR_RNGEN, priv->base + RNG_CR); + + /* clear error indicators */ + writel_relaxed(0, priv->base + RNG_SR); + + return 0; +} + +static void stm32_rng_cleanup(struct hwrng *rng) +{ + struct stm32_rng_private *priv = + container_of(rng, struct stm32_rng_private, rng); + + writel_relaxed(0, priv->base + RNG_CR); + clk_disable_unprepare(priv->clk); +} + +static int stm32_rng_probe(struct platform_device *ofdev) +{ + struct device *dev = &ofdev->dev; + struct device_node *np = ofdev->dev.of_node; + struct stm32_rng_private *priv; + struct resource res; + int err; + + priv = devm_kzalloc(dev, sizeof(struct stm32_rng_private), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + err = of_address_to_resource(np, 0, &res); + if (err) + return err; + + priv->base = devm_ioremap_resource(dev, &res); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->clk = devm_clk_get(&ofdev->dev, NULL); + if (IS_ERR(priv->clk)) + return PTR_ERR(priv->clk); + + dev_set_drvdata(dev, priv); + + priv->rng.name = dev_driver_string(dev), +#ifndef CONFIG_PM + priv->rng.init = stm32_rng_init, + priv->rng.cleanup = stm32_rng_cleanup, +#endif + priv->rng.read = stm32_rng_read, + priv->rng.priv = (unsigned long) dev; + + pm_runtime_set_autosuspend_delay(dev, 100); + pm_runtime_use_autosuspend(dev); + pm_runtime_enable(dev); + + return devm_hwrng_register(dev, &priv->rng); +} + +#ifdef CONFIG_PM +static int stm32_rng_runtime_suspend(struct device *dev) +{ + struct stm32_rng_private *priv = dev_get_drvdata(dev); + + stm32_rng_cleanup(&priv->rng); + + return 0; +} + +static int stm32_rng_runtime_resume(struct device *dev) +{ + struct stm32_rng_private *priv = dev_get_drvdata(dev); + + return stm32_rng_init(&priv->rng); +} +#endif + +static UNIVERSAL_DEV_PM_OPS(stm32_rng_pm_ops, stm32_rng_runtime_suspend, + stm32_rng_runtime_resume, NULL); + +static const struct of_device_id stm32_rng_match[] = { + { + .compatible = "st,stm32-rng", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_rng_match); + +static struct platform_driver stm32_rng_driver = { + .driver = { + .name = "stm32-rng", + .pm = &stm32_rng_pm_ops, + .of_match_table = stm32_rng_match, + }, + .probe = stm32_rng_probe, +}; + +module_platform_driver(stm32_rng_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Daniel Thompson <daniel.thompson@linaro.org>"); +MODULE_DESCRIPTION("STMicroelectronics STM32 RNG device driver"); |