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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-23 16:18:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-23 16:18:25 -0800
commit26b265cd29dde56bf0901c421eabc7ae815f38c4 (patch)
tree83a5418c96ccde8522bda6614063b665fe5e0ec9 /drivers/char/hw_random/msm-rng.c
parent2e7babfa892a55588467ef03b545002e32f31528 (diff)
parentf262f0f5cad0c9eca61d1d383e3b67b57dcbe5ea (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu: - Made x86 ablk_helper generic for ARM - Phase out chainiv in favour of eseqiv (affects IPsec) - Fixed aes-cbc IV corruption on s390 - Added constant-time crypto_memneq which replaces memcmp - Fixed aes-ctr in omap-aes - Added OMAP3 ROM RNG support - Add PRNG support for MSM SoC's - Add and use Job Ring API in caam - Misc fixes [ NOTE! This pull request was sent within the merge window, but Herbert has some questionable email sending setup that makes him public enemy #1 as far as gmail is concerned. So most of his emails seem to be trapped by gmail as spam, resulting in me not seeing them. - Linus ] * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (49 commits) crypto: s390 - Fix aes-cbc IV corruption crypto: omap-aes - Fix CTR mode counter length crypto: omap-sham - Add missing modalias padata: make the sequence counter an atomic_t crypto: caam - Modify the interface layers to use JR API's crypto: caam - Add API's to allocate/free Job Rings crypto: caam - Add Platform driver for Job Ring hwrng: msm - Add PRNG support for MSM SoC's ARM: DT: msm: Add Qualcomm's PRNG driver binding document crypto: skcipher - Use eseqiv even on UP machines crypto: talitos - Simplify key parsing crypto: picoxcell - Simplify and harden key parsing crypto: ixp4xx - Simplify and harden key parsing crypto: authencesn - Simplify key parsing crypto: authenc - Export key parsing helper function crypto: mv_cesa: remove deprecated IRQF_DISABLED hwrng: OMAP3 ROM Random Number Generator support crypto: sha256_ssse3 - also test for BMI2 crypto: mv_cesa - Remove redundant of_match_ptr crypto: sahara - Remove redundant of_match_ptr ...
Diffstat (limited to 'drivers/char/hw_random/msm-rng.c')
-rw-r--r--drivers/char/hw_random/msm-rng.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/char/hw_random/msm-rng.c b/drivers/char/hw_random/msm-rng.c
new file mode 100644
index 000000000000..148521e51dc6
--- /dev/null
+++ b/drivers/char/hw_random/msm-rng.c
@@ -0,0 +1,197 @@
+/*
+ * 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);
+
+ /* no room for word data */
+ if (maxsize < WORD_SZ)
+ return 0;
+
+ 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 = hwrng_register(&rng->hwrng);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register hwrng\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int msm_rng_remove(struct platform_device *pdev)
+{
+ struct msm_rng *rng = platform_get_drvdata(pdev);
+
+ hwrng_unregister(&rng->hwrng);
+ 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,
+ .remove = msm_rng_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .owner = THIS_MODULE,
+ .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");