Commit f29cd5bb authored by Om Prakash Singh's avatar Om Prakash Singh Committed by Herbert Xu
Browse files

crypto: qcom-rng - Add hw_random interface support 



Add hw_random interface support in qcom-rng driver as new IP block
in Qualcomm SoC has inbuilt NIST SP800 90B compliant entropic source
to generate true random number.

Keeping current rng_alg interface as well for random number generation
using Kernel Crypto API.

Signed-off-by: default avatarOm Prakash Singh <quic_omprsing@quicinc.com>
Reviewed-by: default avatarBjorn Andersson <quic_bjorande@quicinc.com>
Signed-off-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Acked-by: default avatarOm Prakash Singh <quic_omprsing@quicinc.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a4d7e9ec

drivers/crypto/qcom-rng.c

+58 −7
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/acpi.h>

#include <linux/clk.h>

#include <linux/crypto.h>

#include <linux/hw_random.h>

#include <linux/io.h>

#include <linux/iopoll.h>

#include <linux/kernel.h>
@@ -28,17 +29,25 @@ 


#define WORD_SZ			4



#define QCOM_TRNG_QUALITY	1024



struct qcom_rng {

	struct mutex lock;

	void __iomem *base;

	struct clk *clk;

	unsigned int skip_init;

	struct hwrng hwrng;

	struct qcom_rng_of_data *of_data;

};



struct qcom_rng_ctx {

	struct qcom_rng *rng;

};



struct qcom_rng_of_data {

	bool skip_init;

	bool hwrng_support;

};



static struct qcom_rng *qcom_rng_dev;



static int qcom_rng_read(struct qcom_rng *rng, u8 *data, unsigned int max)
@@ -66,11 +75,11 @@ static int qcom_rng_read(struct qcom_rng *rng, u8 *data, unsigned int max) 
		} else {

			/* copy only remaining bytes */

			memcpy(data, &val, max - currsize);

			break;

			currsize = max;

		}

	} while (currsize < max);



	return 0;

	return currsize;

}



static int qcom_rng_generate(struct crypto_rng *tfm,
@@ -92,6 +101,9 @@ static int qcom_rng_generate(struct crypto_rng *tfm, 
	mutex_unlock(&rng->lock);

	clk_disable_unprepare(rng->clk);



	if (ret >= 0)

		ret = 0;



	return ret;

}
@@ -101,6 +113,13 @@ static int qcom_rng_seed(struct crypto_rng *tfm, const u8 *seed, 
	return 0;

}



static int qcom_hwrng_read(struct hwrng *hwrng, void *data, size_t max, bool wait)

{

	struct qcom_rng *qrng = container_of(hwrng, struct qcom_rng, hwrng);



	return qcom_rng_read(qrng, data, max);

}



static int qcom_rng_enable(struct qcom_rng *rng)

{

	u32 val;
@@ -136,7 +155,7 @@ static int qcom_rng_init(struct crypto_tfm *tfm) 


	ctx->rng = qcom_rng_dev;



	if (!ctx->rng->skip_init)

	if (!ctx->rng->of_data->skip_init)

		return qcom_rng_enable(ctx->rng);



	return 0;
@@ -177,15 +196,31 @@ static int qcom_rng_probe(struct platform_device *pdev) 
	if (IS_ERR(rng->clk))

		return PTR_ERR(rng->clk);



	rng->skip_init = (unsigned long)device_get_match_data(&pdev->dev);

	rng->of_data = (struct qcom_rng_of_data *)of_device_get_match_data(&pdev->dev);



	qcom_rng_dev = rng;

	ret = crypto_register_rng(&qcom_rng_alg);

	if (ret) {

		dev_err(&pdev->dev, "Register crypto rng failed: %d\n", ret);

		qcom_rng_dev = NULL;

		return ret;

	}



	if (rng->of_data->hwrng_support) {

		rng->hwrng.name = "qcom_hwrng";

		rng->hwrng.read = qcom_hwrng_read;

		rng->hwrng.quality = QCOM_TRNG_QUALITY;

		ret = devm_hwrng_register(&pdev->dev, &rng->hwrng);

		if (ret) {

			dev_err(&pdev->dev, "Register hwrng failed: %d\n", ret);

			qcom_rng_dev = NULL;

			goto fail;

		}

	}



	return ret;

fail:

	crypto_unregister_rng(&qcom_rng_alg);

	return ret;

}
@@ -198,6 +233,21 @@ static int qcom_rng_remove(struct platform_device *pdev) 
	return 0;

}



static struct qcom_rng_of_data qcom_prng_of_data = {

	.skip_init = false,

	.hwrng_support = false,

};



static struct qcom_rng_of_data qcom_prng_ee_of_data = {

	.skip_init = true,

	.hwrng_support = false,

};



static struct qcom_rng_of_data qcom_trng_of_data = {

	.skip_init = true,

	.hwrng_support = true,

};



static const struct acpi_device_id __maybe_unused qcom_rng_acpi_match[] = {

	{ .id = "QCOM8160", .driver_data = 1 },

	{}
@@ -205,8 +255,9 @@ static const struct acpi_device_id __maybe_unused qcom_rng_acpi_match[] = { 
MODULE_DEVICE_TABLE(acpi, qcom_rng_acpi_match);



static const struct of_device_id __maybe_unused qcom_rng_of_match[] = {

	{ .compatible = "qcom,prng", .data = (void *)0},

	{ .compatible = "qcom,prng-ee", .data = (void *)1},

	{ .compatible = "qcom,prng", .data = &qcom_prng_of_data },

	{ .compatible = "qcom,prng-ee", .data = &qcom_prng_ee_of_data },

	{ .compatible = "qcom,trng", .data = &qcom_trng_of_data },

	{}

};

MODULE_DEVICE_TABLE(of, qcom_rng_of_match);