Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761625AbbBJAH4 (ORCPT ); Mon, 9 Feb 2015 19:07:56 -0500 Received: from mail-gw1-out.broadcom.com ([216.31.210.62]:19097 "EHLO mail-gw1-out.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760105AbbBJAHv (ORCPT ); Mon, 9 Feb 2015 19:07:51 -0500 X-IronPort-AV: E=Sophos;i="5.09,547,1418112000"; d="scan'208";a="56882850" From: Scott Branden To: , Rob Herring , Pawel Moll , Mark Rutland , "Ian Campbell" , Kumar Gala , Matt Mackall , Herbert Xu , Grant Likely CC: Ray Jui , Jonathan Richardson , Dmitry Torokhov , Anatol Pomazao , , , , Scott Branden Subject: [PATCH 1/2] hwrng: iproc-rng200 - Add Broadcom IPROC RNG driver Date: Mon, 9 Feb 2015 16:07:09 -0800 Message-ID: <1423526830-29516-2-git-send-email-sbranden@broadcom.com> X-Mailer: git-send-email 2.2.2 In-Reply-To: <1423526830-29516-1-git-send-email-sbranden@broadcom.com> References: <1423526830-29516-1-git-send-email-sbranden@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9189 Lines: 300 This adds a driver for random number generator present on Broadcom IPROC devices. Reviewed-by: Ray Jui Signed-off-by: Scott Branden --- drivers/char/hw_random/Kconfig | 13 ++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/iproc-rng200.c | 239 ++++++++++++++++++++++++++++++++++ 3 files changed, 253 insertions(+) create mode 100644 drivers/char/hw_random/iproc-rng200.c diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index de57b38..f48cf11 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -101,6 +101,19 @@ config HW_RANDOM_BCM2835 If unsure, say Y. +config HW_RANDOM_IPROC_RNG200 + tristate "Broadcom iProc RNG200 support" + depends on ARCH_BCM_IPROC + default HW_RANDOM + ---help--- + This driver provides kernel-side support for the RNG200 + hardware found on the Broadcom iProc SoCs. + + To compile this driver as a module, choose M here: the + module will be called iproc-rng200 + + If unsure, say Y. + config HW_RANDOM_GEODE tristate "AMD Geode HW Random Number Generator support" depends on X86_32 && PCI diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index 0b4cd57..055bb01 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -28,5 +28,6 @@ obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o obj-$(CONFIG_HW_RANDOM_EXYNOS) += exynos-rng.o 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_XGENE) += xgene-rng.o diff --git a/drivers/char/hw_random/iproc-rng200.c b/drivers/char/hw_random/iproc-rng200.c new file mode 100644 index 0000000..0fef15d --- /dev/null +++ b/drivers/char/hw_random/iproc-rng200.c @@ -0,0 +1,239 @@ +/* +* Copyright (C) 2014 Broadcom Corporation +* +* This program 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 version 2. +* +* This program is distributed "as is" WITHOUT ANY WARRANTY of any +* kind, whether express or implied; without even the implied warranty +* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +*/ +/* + * DESCRIPTION: The Broadcom iProc RNG200 Driver + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* Registers */ +#define RNG_CTRL_OFFSET 0x00 +#define RNG_CTRL_RNG_RBGEN_MASK 0x00001FFF +#define RNG_CTRL_RNG_RBGEN_ENABLE 0x00000001 +#define RNG_CTRL_RNG_RBGEN_DISABLE 0x00000000 + +#define RNG_SOFT_RESET_OFFSET 0x04 +#define RNG_SOFT_RESET_RNG_SOFT_RESET_MASK 0x00000001 +#define RNG_SOFT_RESET_RNG_SOFT_RESET_ACTIVE 0x00000001 +#define RNG_SOFT_RESET_RNG_SOFT_RESET_CLEAR 0x00000000 + +#define RBG_SOFT_RESET_OFFSET 0x08 +#define RBG_SOFT_RESET_RNG_SOFT_RESET_MASK 0x00000001 +#define RBG_SOFT_RESET_RNG_SOFT_RESET_ACTIVE 0x00000001 +#define RBG_SOFT_RESET_RNG_SOFT_RESET_CLEAR 0x00000000 + +#define RNG_INT_STATUS_OFFSET 0x18 +#define RNG_INT_STATUS_MASTER_FAIL_LOCKOUT_IRQ_MASK 0x80000000 +#define RNG_INT_STATUS_STARTUP_TRANSITIONS_MET_IRQ_MASK 0x00020000 +#define RNG_INT_STATUS_NIST_FAIL_IRQ_MASK 0x00000020 +#define RNG_INT_STATUS_TOTAL_BITS_COUNT_IRQ_MASK 0x00000001 + +#define RNG_FIFO_DATA_OFFSET 0x20 + +#define RNG_FIFO_COUNT_OFFSET 0x24 +#define RNG_FIFO_COUNT_RNG_FIFO_COUNT_MASK 0x000000FF + +static void iproc_rng200_restart(void __iomem *rng_base) +{ + uint32_t val; + + /* Disable RBG */ + val = ioread32(rng_base + RNG_CTRL_OFFSET); + val &= ~RNG_CTRL_RNG_RBGEN_MASK; + val |= RNG_CTRL_RNG_RBGEN_DISABLE; + iowrite32(val, rng_base + RNG_CTRL_OFFSET); + + /* Clear all interrupt status */ + iowrite32(0xFFFFFFFFUL, rng_base + RNG_INT_STATUS_OFFSET); + + /* Reset RNG and RBG */ + val = ioread32(rng_base + RBG_SOFT_RESET_OFFSET); + val &= ~RBG_SOFT_RESET_RNG_SOFT_RESET_MASK; + val |= RBG_SOFT_RESET_RNG_SOFT_RESET_ACTIVE; + iowrite32(val, rng_base + RBG_SOFT_RESET_OFFSET); + + val = ioread32(rng_base + RNG_SOFT_RESET_OFFSET); + val &= ~RNG_SOFT_RESET_RNG_SOFT_RESET_MASK; + val |= RNG_SOFT_RESET_RNG_SOFT_RESET_ACTIVE; + iowrite32(val, rng_base + RNG_SOFT_RESET_OFFSET); + + val = ioread32(rng_base + RNG_SOFT_RESET_OFFSET); + val &= ~RNG_SOFT_RESET_RNG_SOFT_RESET_MASK; + val |= RNG_SOFT_RESET_RNG_SOFT_RESET_CLEAR; + iowrite32(val, rng_base + RNG_SOFT_RESET_OFFSET); + + val = ioread32(rng_base + RBG_SOFT_RESET_OFFSET); + val &= ~RBG_SOFT_RESET_RNG_SOFT_RESET_MASK; + val |= RBG_SOFT_RESET_RNG_SOFT_RESET_CLEAR; + iowrite32(val, rng_base + RBG_SOFT_RESET_OFFSET); + + /* Enable RBG */ + val = ioread32(rng_base + RNG_CTRL_OFFSET); + val &= ~RNG_CTRL_RNG_RBGEN_MASK; + val |= RNG_CTRL_RNG_RBGEN_ENABLE; + iowrite32(val, rng_base + RNG_CTRL_OFFSET); +} + +static int iproc_rng200_read(struct hwrng *rng, void *buf, size_t max, + bool wait) +{ + uint32_t status = 0; + uint32_t num_remaining = max; + + #define MAX_RESETS_PER_READ 1 + uint32_t num_resets = 0; + + #define MAX_IDLE_TIME (1 * HZ) + unsigned long idle_endtime = jiffies + MAX_IDLE_TIME; + + /* Retrieve HW RNG registers base address. */ + void __iomem *rng_base = (void __iomem *)rng->priv; + + while ((num_remaining > 0) && time_before(jiffies, idle_endtime)) { + + /* Is RNG sane? If not, reset it. */ + status = ioread32(rng_base + RNG_INT_STATUS_OFFSET); + if ((status & (RNG_INT_STATUS_MASTER_FAIL_LOCKOUT_IRQ_MASK | + RNG_INT_STATUS_NIST_FAIL_IRQ_MASK)) != 0) { + + if (num_resets >= MAX_RESETS_PER_READ) + return max - num_remaining; + + iproc_rng200_restart(rng_base); + num_resets++; + } + + /* Are there any random numbers available? */ + if ((ioread32(rng_base + RNG_FIFO_COUNT_OFFSET) & + RNG_FIFO_COUNT_RNG_FIFO_COUNT_MASK) > 0) { + + if (num_remaining >= sizeof(uint32_t)) { + /* Buffer has room to store entire word */ + *(uint32_t *)buf = ioread32(rng_base + + RNG_FIFO_DATA_OFFSET); + buf += sizeof(uint32_t); + num_remaining -= sizeof(uint32_t); + } else { + /* Buffer can only store partial word */ + uint32_t rnd_number = ioread32(rng_base + + RNG_FIFO_DATA_OFFSET); + memcpy(buf, &rnd_number, num_remaining); + buf += num_remaining; + num_remaining = 0; + } + + /* Reset the IDLE timeout */ + idle_endtime = jiffies + MAX_IDLE_TIME; + } else { + if (!wait) + /* Cannot wait, return immediately */ + return max - num_remaining; + + /* Can wait, give others chance to run */ + cpu_relax(); + } + } + + return max - num_remaining; +} + +static struct hwrng iproc_rng200_ops = { + .name = "iproc-rng200", + .read = iproc_rng200_read, +}; + +static int iproc_rng200_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + void __iomem *rng_base = 0; + uint32_t val = 0; + int err = 0; + + /* Map peripheral */ + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + if (!res) { + dev_err(dev, "failed to get rng resources"); + return -ENODEV; + } + + rng_base = devm_ioremap_resource(dev, res); + if (!rng_base) { + dev_err(dev, "failed to remap rng regs"); + return -ENODEV; + } + + iproc_rng200_ops.priv = (unsigned long)rng_base; + + /* Setup RNG. */ + val = ioread32(rng_base + RNG_CTRL_OFFSET); + val &= ~RNG_CTRL_RNG_RBGEN_MASK; + val |= RNG_CTRL_RNG_RBGEN_ENABLE; + iowrite32(val, rng_base + RNG_CTRL_OFFSET); + + /* Register driver */ + err = hwrng_register(&iproc_rng200_ops); + if (err) { + dev_err(dev, "hwrng registration failed\n"); + return err; + } + dev_info(dev, "hwrng registered\n"); + + return 0; +} + +static int iproc_rng200_remove(struct platform_device *pdev) +{ + uint32_t val = 0; + void __iomem *rng_base = (void __iomem *)iproc_rng200_ops.priv; + + /* Unregister driver */ + hwrng_unregister(&iproc_rng200_ops); + + /* Disable RNG hardware */ + val = ioread32(rng_base + RNG_CTRL_OFFSET); + val &= ~RNG_CTRL_RNG_RBGEN_MASK; + val |= RNG_CTRL_RNG_RBGEN_DISABLE; + iowrite32(val, rng_base + RNG_CTRL_OFFSET); + + return 0; +} + +static const struct of_device_id iproc_rng200_of_match[] = { + { .compatible = "brcm,iproc-rng200", }, + {}, +}; +MODULE_DEVICE_TABLE(of, iproc_rng200_of_match); + +static struct platform_driver iproc_rng200_driver = { + .driver = { + .name = "iproc-rng200", + .of_match_table = iproc_rng200_of_match, + }, + .probe = iproc_rng200_probe, + .remove = iproc_rng200_remove, +}; +module_platform_driver(iproc_rng200_driver); + +MODULE_AUTHOR("Broadcom"); +MODULE_DESCRIPTION("iProc RNG200 Random Number Generator driver"); +MODULE_LICENSE("GPL v2"); -- 2.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/