i.MX6SX: crypto/fsl: fix entropy delay value

RNG Hardware error is reported due to incorrect entropy delay

rng self test are run to determine the correct ent_dly.
test is executed with different voltage and temperature to identify the
worst case value for ent_dly. after adding a margin value(1000),
ent_dly should be at least 12000.

Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>

diff --git a/drivers/crypto/fsl/jr.c b/drivers/crypto/fsl/jr.c
index 1d951cf0a64f16424a3b68b03445ac0854983926..85a3dac79603763ec681c5eae0f43f15be99399e 100644 (file)
--- a/drivers/crypto/fsl/jr.c
+++ b/drivers/crypto/fsl/jr.c
@@ -623,7 +623,7 @@ static void kick_trng(int ent_delay, ccsr_sec_t *sec)
 
 static int rng_init(uint8_t sec_idx, ccsr_sec_t *sec)
 {
-       int ret, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN;
+       int ret, gen_sk, ent_delay = RTSDCTL_ENT_DLY;
        struct rng4tst __iomem *rng =
                        (struct rng4tst __iomem *)&sec->rng;
        u32 inst_handles;
@@ -652,6 +652,15 @@ static int rng_init(uint8_t sec_idx, ccsr_sec_t *sec)
                 * the RNG.
                 */
                ret = instantiate_rng(sec_idx, sec, gen_sk);
+               /*
+                * entropy delay is calculated via self-test method.
+                * self-test are run across different volatge, temp.
+                * if worst case value for ent_dly is identified,
+                * loop can be skipped for that platform.
+                */
+               if (IS_ENABLED(CONFIG_MX6SX))
+                       break;
+
        } while ((ret == -1) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
        if (ret) {
                printf("SEC%u:  Failed to instantiate RNG\n", sec_idx);

diff --git a/include/fsl_sec.h b/include/fsl_sec.h
index 7b6e3e2c20d7d6e1e6d5c78c7deccba2b236c798..d57c4ca820c87a363851a82fc33ff0bb3713ffb8 100644 (file)
--- a/include/fsl_sec.h
+++ b/include/fsl_sec.h
@@ -48,7 +48,11 @@ struct rng4tst {
        u32 rtmctl;             /* misc. control register */
        u32 rtscmisc;           /* statistical check misc. register */
        u32 rtpkrrng;           /* poker range register */
-#define RTSDCTL_ENT_DLY_MIN    3200
+#ifdef CONFIG_MX6SX
+#define RTSDCTL_ENT_DLY                12000
+#else
+#define RTSDCTL_ENT_DLY                3200
+#endif
 #define RTSDCTL_ENT_DLY_MAX    12800
        union {
                u32 rtpkrmax;   /* PRGM=1: poker max. limit register */