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Commit e5ffbfc1 authored by Alex Porosanu's avatar Alex Porosanu Committed by Herbert Xu
Browse files

crypto: caam - enable raw data instead of von Neumann data 



The sampling of the oscillator can be done in multiple modes for
generating the entropy value. By default, this is set to von
Neumann. This patch changes the sampling to raw data, since it
has been discovered that the generated entropy has a better
'quality'.

Signed-off-by: default avatarAlex Porosanu <alexandru.porosanu@freescale.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent eeaa1724

drivers/crypto/caam/ctrl.c

+10 −1
Original line number Diff line number Diff line
@@ -357,8 +357,17 @@ static void kick_trng(struct platform_device *pdev, int ent_delay) 
	wr_reg32(&r4tst->rtfrqmin, ent_delay >> 2);

	/* disable maximum frequency count */

	wr_reg32(&r4tst->rtfrqmax, RTFRQMAX_DISABLE);

	/* read the control register */

	val = rd_reg32(&r4tst->rtmctl);

	/*

	 * select raw sampling in both entropy shifter

	 * and statistical checker

	 */

	setbits32(&val, RTMCTL_SAMP_MODE_RAW_ES_SC);

	/* put RNG4 into run mode */

	clrbits32(&r4tst->rtmctl, RTMCTL_PRGM);

	clrbits32(&val, RTMCTL_PRGM);

	/* write back the control register */

	wr_reg32(&r4tst->rtmctl, val);

}



/**

drivers/crypto/caam/regs.h

+10 −0
Original line number Diff line number Diff line
@@ -269,6 +269,16 @@ struct rngtst { 
/* RNG4 TRNG test registers */

struct rng4tst {

#define RTMCTL_PRGM	0x00010000	/* 1 -> program mode, 0 -> run mode */

#define RTMCTL_SAMP_MODE_VON_NEUMANN_ES_SC	0 /* use von Neumann data in

						     both entropy shifter and

						     statistical checker */

#define RTMCTL_SAMP_MODE_RAW_ES_SC		1 /* use raw data in both

						     entropy shifter and

						     statistical checker */

#define RTMCTL_SAMP_MODE_VON_NEUMANN_ES_RAW_SC	2 /* use von Neumann data in

						     entropy shifter, raw data

						     in statistical checker */

#define RTMCTL_SAMP_MODE_INVALID		3 /* invalid combination */

	u32 rtmctl;		/* misc. control register */

	u32 rtscmisc;		/* statistical check misc. register */

	u32 rtpkrrng;		/* poker range register */