crypto: atmel-sha - fix context switches

This patch saves the value of the internal hash register at the end of an
'update' operation then restores this value before starting the next
'update'. This way the driver can now properly handle context switches.

WARNING: only hardware versions from sama5d4x and later provide the
needed interface to update the internal hash value. Especially, sama5d3x
cannot implement this feature so context switches are still broken.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/atmel-sha-regs.h b/drivers/crypto/atmel-sha-regs.h
index 83b2d74..e088971 100644
--- a/drivers/crypto/atmel-sha-regs.h
+++ b/drivers/crypto/atmel-sha-regs.h
@@ -8,6 +8,8 @@
 #define SHA_CR_START			(1 << 0)
 #define SHA_CR_FIRST			(1 << 4)
 #define SHA_CR_SWRST			(1 << 8)
+#define SHA_CR_WUIHV			(1 << 12)
+#define SHA_CR_WUIEHV			(1 << 13)
 
 #define SHA_MR				0x04
 #define SHA_MR_MODE_MASK		(0x3 << 0)
@@ -15,6 +17,8 @@
 #define SHA_MR_MODE_AUTO		0x1
 #define SHA_MR_MODE_PDC			0x2
 #define SHA_MR_PROCDLY			(1 << 4)
+#define SHA_MR_UIHV			(1 << 5)
+#define SHA_MR_UIEHV			(1 << 6)
 #define SHA_MR_ALGO_SHA1		(0 << 8)
 #define SHA_MR_ALGO_SHA256		(1 << 8)
 #define SHA_MR_ALGO_SHA384		(2 << 8)