crypto: hisilicon/trng - add version to adapt new algorithm

Kunpeng930 supports trng and prng, but Kunpeng920 only supports trng.

Therefore, version information is added to ensure that prng is not
registered to Crypto subsystem on Kunpeng920.

Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/hisilicon/trng/trng.c

@@ -18,6 +18,8 @@
 #define HISI_TRNG_REG		0x00F0
 #define HISI_TRNG_BYTES		4
 #define HISI_TRNG_QUALITY	512
+#define HISI_TRNG_VERSION	0x01B8
+#define HISI_TRNG_VER_V1	GENMASK(31, 0)
 #define SLEEP_US		10
 #define TIMEOUT_US		10000
 #define SW_DRBG_NUM_SHIFT	2
@@ -50,6 +52,7 @@ struct hisi_trng {
 	struct hisi_trng_list *trng_list;
 	struct list_head list;
 	struct hwrng rng;
+	u32 ver;
 	bool is_used;
 	struct mutex mutex;
 };
@@ -260,6 +263,7 @@ static int hisi_trng_probe(struct platform_device *pdev)
 		return PTR_ERR(trng->base);
 
 	trng->is_used = false;
+	trng->ver = readl(trng->base + HISI_TRNG_VERSION);
 	if (!trng_devices.is_init) {
 		INIT_LIST_HEAD(&trng_devices.list);
 		mutex_init(&trng_devices.lock);
@@ -267,7 +271,8 @@ static int hisi_trng_probe(struct platform_device *pdev)
 	}
 
 	hisi_trng_add_to_list(trng);
-	if (atomic_inc_return(&trng_active_devs) == 1) {
+	if (trng->ver != HISI_TRNG_VER_V1 &&
+	    atomic_inc_return(&trng_active_devs) == 1) {
 		ret = crypto_register_rng(&hisi_trng_alg);
 		if (ret) {
 			dev_err(&pdev->dev,
@@ -289,7 +294,8 @@ static int hisi_trng_probe(struct platform_device *pdev)
 	return ret;
 
 err_crypto_unregister:
-	if (atomic_dec_return(&trng_active_devs) == 0)
+	if (trng->ver != HISI_TRNG_VER_V1 &&
+	    atomic_dec_return(&trng_active_devs) == 0)
 		crypto_unregister_rng(&hisi_trng_alg);
 
 err_remove_from_list:
@@ -305,7 +311,8 @@ static int hisi_trng_remove(struct platform_device *pdev)
 	while (hisi_trng_del_from_list(trng))
 		;
 
-	if (atomic_dec_return(&trng_active_devs) == 0)
+	if (trng->ver != HISI_TRNG_VER_V1 &&
+	    atomic_dec_return(&trng_active_devs) == 0)
 		crypto_unregister_rng(&hisi_trng_alg);
 
 	return 0;