diff options
Diffstat (limited to 'drivers/char/hw_random/msm-rng.c')
| -rw-r--r-- | drivers/char/hw_random/msm-rng.c | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/drivers/char/hw_random/msm-rng.c b/drivers/char/hw_random/msm-rng.c deleted file mode 100644 index 841fee845ec9..000000000000 --- a/drivers/char/hw_random/msm-rng.c +++ /dev/null @@ -1,183 +0,0 @@ -/* - * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 and - * only version 2 as published by the Free Software Foundation. - * - * This program 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/err.h> -#include <linux/hw_random.h> -#include <linux/io.h> -#include <linux/module.h> -#include <linux/of.h> -#include <linux/platform_device.h> - -/* Device specific register offsets */ -#define PRNG_DATA_OUT 0x0000 -#define PRNG_STATUS 0x0004 -#define PRNG_LFSR_CFG 0x0100 -#define PRNG_CONFIG 0x0104 - -/* Device specific register masks and config values */ -#define PRNG_LFSR_CFG_MASK 0x0000ffff -#define PRNG_LFSR_CFG_CLOCKS 0x0000dddd -#define PRNG_CONFIG_HW_ENABLE BIT(1) -#define PRNG_STATUS_DATA_AVAIL BIT(0) - -#define MAX_HW_FIFO_DEPTH 16 -#define MAX_HW_FIFO_SIZE (MAX_HW_FIFO_DEPTH * 4) -#define WORD_SZ 4 - -struct msm_rng { - void __iomem *base; - struct clk *clk; - struct hwrng hwrng; -}; - -#define to_msm_rng(p) container_of(p, struct msm_rng, hwrng) - -static int msm_rng_enable(struct hwrng *hwrng, int enable) -{ - struct msm_rng *rng = to_msm_rng(hwrng); - u32 val; - int ret; - - ret = clk_prepare_enable(rng->clk); - if (ret) - return ret; - - if (enable) { - /* Enable PRNG only if it is not already enabled */ - val = readl_relaxed(rng->base + PRNG_CONFIG); - if (val & PRNG_CONFIG_HW_ENABLE) - goto already_enabled; - - val = readl_relaxed(rng->base + PRNG_LFSR_CFG); - val &= ~PRNG_LFSR_CFG_MASK; - val |= PRNG_LFSR_CFG_CLOCKS; - writel(val, rng->base + PRNG_LFSR_CFG); - - val = readl_relaxed(rng->base + PRNG_CONFIG); - val |= PRNG_CONFIG_HW_ENABLE; - writel(val, rng->base + PRNG_CONFIG); - } else { - val = readl_relaxed(rng->base + PRNG_CONFIG); - val &= ~PRNG_CONFIG_HW_ENABLE; - writel(val, rng->base + PRNG_CONFIG); - } - -already_enabled: - clk_disable_unprepare(rng->clk); - return 0; -} - -static int msm_rng_read(struct hwrng *hwrng, void *data, size_t max, bool wait) -{ - struct msm_rng *rng = to_msm_rng(hwrng); - size_t currsize = 0; - u32 *retdata = data; - size_t maxsize; - int ret; - u32 val; - - /* calculate max size bytes to transfer back to caller */ - maxsize = min_t(size_t, MAX_HW_FIFO_SIZE, max); - - ret = clk_prepare_enable(rng->clk); - if (ret) - return ret; - - /* read random data from hardware */ - do { - val = readl_relaxed(rng->base + PRNG_STATUS); - if (!(val & PRNG_STATUS_DATA_AVAIL)) - break; - - val = readl_relaxed(rng->base + PRNG_DATA_OUT); - if (!val) - break; - - *retdata++ = val; - currsize += WORD_SZ; - - /* make sure we stay on 32bit boundary */ - if ((maxsize - currsize) < WORD_SZ) - break; - } while (currsize < maxsize); - - clk_disable_unprepare(rng->clk); - - return currsize; -} - -static int msm_rng_init(struct hwrng *hwrng) -{ - return msm_rng_enable(hwrng, 1); -} - -static void msm_rng_cleanup(struct hwrng *hwrng) -{ - msm_rng_enable(hwrng, 0); -} - -static int msm_rng_probe(struct platform_device *pdev) -{ - struct resource *res; - struct msm_rng *rng; - int ret; - - rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); - if (!rng) - return -ENOMEM; - - platform_set_drvdata(pdev, rng); - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - rng->base = devm_ioremap_resource(&pdev->dev, res); - if (IS_ERR(rng->base)) - return PTR_ERR(rng->base); - - rng->clk = devm_clk_get(&pdev->dev, "core"); - if (IS_ERR(rng->clk)) - return PTR_ERR(rng->clk); - - rng->hwrng.name = KBUILD_MODNAME, - rng->hwrng.init = msm_rng_init, - rng->hwrng.cleanup = msm_rng_cleanup, - rng->hwrng.read = msm_rng_read, - - ret = devm_hwrng_register(&pdev->dev, &rng->hwrng); - if (ret) { - dev_err(&pdev->dev, "failed to register hwrng\n"); - return ret; - } - - return 0; -} - -static const struct of_device_id msm_rng_of_match[] = { - { .compatible = "qcom,prng", }, - {} -}; -MODULE_DEVICE_TABLE(of, msm_rng_of_match); - -static struct platform_driver msm_rng_driver = { - .probe = msm_rng_probe, - .driver = { - .name = KBUILD_MODNAME, - .of_match_table = of_match_ptr(msm_rng_of_match), - } -}; -module_platform_driver(msm_rng_driver); - -MODULE_ALIAS("platform:" KBUILD_MODNAME); -MODULE_AUTHOR("The Linux Foundation"); -MODULE_DESCRIPTION("Qualcomm MSM random number generator driver"); -MODULE_LICENSE("GPL v2"); |