[PATCH 00/12] crypto: atmel - refactor common i2c support and add SHA256 ahash support

[PATCH 00/12] crypto: atmel - refactor common i2c support and add SHA256 ahash support

[Lothar Rubusch]

This series restructures the Atmel secure element drivers around a
shared atmel-i2c core and adds SHA256 ahash support for ATSHA204A and
ECC based devices.

The existing drivers duplicated substantial parts of the transport,
RNG, EEPROM and device management logic. This series consolidates the
common functionality into the shared i2c core and converts the client
drivers to capability based allocation.

The series also introduces per-device timing configuration through
match data, moves sanity checks and RNG handling into the core driver,
updates workqueue handling and cleans up internal constants and helper
definitions.

The final patch adds SHA256 ahash support using the hardware SHA engine
provided by the devices.

ATSHA204A devices require software-side SHA256 padding according to
FIPS 180-4, while newer ECC devices provide a dedicated SHA final
command and perform padding internally in hardware.

Supporting the SHA engine also requires changes to the command
transport path. SHA operations must execute as a strict uninterrupted
sequence consisting of SHA INIT, one or more SHA COMPUTE commands and,
for ECC devices, a terminating SHA FINAL command. The device loses its
internal SHA state if it enters sleep mode or if unrelated commands
are interleaved during the transaction.

To satisfy these hardware requirements, the send/receive path is split
into a low-level transfer helper and a higher-level wrapper managing
wakeup, sleep and locking. SHA operations keep the device awake and
hold the i2c lock for the full duration of the hashing transaction.

The series has been tested on ATSHA204A and ATECC508A devices.
Tests are ongoing/pending on ATECC608A and ATECC608B.
---
Lothar Rubusch (12):
  crypto: atmel - introduce shared I2C client management
  crypto: atmel - move capability-based client allocation into i2c core
  crypto: atmel - remove obsolete CONFIG_OF guard
  crypto: atmel - add per-device timing and match-data driven
    configuration
  crypto: atmel - move RNG support into common i2c core
  crypto: atmel - move EEPROM access support into common i2c core
  crypto: atmel - expose CONFIG zone through sysfs
  crypto: atmel - move device sanity check to core driver
  crypto: atmel - check client data in remove callbacks
  crypto: atmel - update workqueue flags and add flush on exit
  crypto: atmel - refactor and localize driver constants
  crypto: atmel - add SHA256 ahash support

 drivers/crypto/atmel-ecc.c     | 252 +++++++-----
 drivers/crypto/atmel-i2c.c     | 679 +++++++++++++++++++++++++++++----
 drivers/crypto/atmel-i2c.h     | 180 +++++----
 drivers/crypto/atmel-sha204a.c | 284 +++++++-------
 4 files changed, 1010 insertions(+), 385 deletions(-)

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>

base-commit: f7dd32c5179d7755de18e21d5674b08f9e5cb180
-- 
2.53.0

[PATCH 01/12] crypto: atmel - introduce shared I2C client management

[Lothar Rubusch]

Introduce a shared I2C client management infrastructure in the
atmel-i2c core and convert the atmel-ecc and atmel-sha204a drivers
to use it.

Replace the driver-local atmel_ecc_driver_data structure with the
common atmel_i2c_mgmt instance, providing a shared client list and
locking for compatible Atmel secure element devices. Add a common
atmel_i2c_unregister_client() helper to centralize client removal
handling.

Refactor both drivers to use module_i2c_driver() and move duplicated
client list handling into the shared infrastructure. Probe and remove
paths are updated accordingly, including consistent error unwinding
for client registration failures.

Subsequent patches will build on the shared client infrastructure.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     | 58 ++++++++++++++--------------------
 drivers/crypto/atmel-i2c.c     | 15 +++++++++
 drivers/crypto/atmel-i2c.h     |  5 ++-
 drivers/crypto/atmel-sha204a.c | 38 ++++++++++++----------
 4 files changed, 65 insertions(+), 51 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index 3738a4eb8701..cba4238735cc 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -23,8 +23,6 @@
 #include <crypto/kpp.h>
 #include "atmel-i2c.h"
 
-static struct atmel_ecc_driver_data driver_data;
-
 /**
  * struct atmel_ecdh_ctx - transformation context
  * @client     : pointer to i2c client device
@@ -209,14 +207,14 @@ static struct i2c_client *atmel_ecc_i2c_client_alloc(void)
 	int min_tfm_cnt = INT_MAX;
 	int tfm_cnt;
 
-	spin_lock(&driver_data.i2c_list_lock);
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 
-	if (list_empty(&driver_data.i2c_client_list)) {
-		spin_unlock(&driver_data.i2c_list_lock);
+	if (list_empty(&atmel_i2c_mgmt.i2c_client_list)) {
+		spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 		return ERR_PTR(-ENODEV);
 	}
 
-	list_for_each_entry(i2c_priv, &driver_data.i2c_client_list,
+	list_for_each_entry(i2c_priv, &atmel_i2c_mgmt.i2c_client_list,
 			    i2c_client_list_node) {
 		tfm_cnt = atomic_read(&i2c_priv->tfm_count);
 		if (tfm_cnt < min_tfm_cnt) {
@@ -232,7 +230,7 @@ static struct i2c_client *atmel_ecc_i2c_client_alloc(void)
 		client = min_i2c_priv->client;
 	}
 
-	spin_unlock(&driver_data.i2c_list_lock);
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 
 	return client;
 }
@@ -319,27 +317,34 @@ static int atmel_ecc_probe(struct i2c_client *client)
 
 	ret = atmel_i2c_probe(client);
 	if (ret)
-		return ret;
+		goto done;
 
 	i2c_priv = i2c_get_clientdata(client);
 
-	spin_lock(&driver_data.i2c_list_lock);
+	/* add to client list */
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 	list_add_tail(&i2c_priv->i2c_client_list_node,
-		      &driver_data.i2c_client_list);
-	spin_unlock(&driver_data.i2c_list_lock);
+		      &atmel_i2c_mgmt.i2c_client_list);
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 
+	/* register algorithms */
 	ret = crypto_register_kpp(&atmel_ecdh_nist_p256);
 	if (ret) {
-		spin_lock(&driver_data.i2c_list_lock);
-		list_del(&i2c_priv->i2c_client_list_node);
-		spin_unlock(&driver_data.i2c_list_lock);
-
 		dev_err(&client->dev, "%s alg registration failed\n",
 			atmel_ecdh_nist_p256.base.cra_driver_name);
+		goto err_list_del;
 	} else {
 		dev_info(&client->dev, "atmel ecc algorithms registered in /proc/crypto\n");
 	}
 
+	goto done;
+
+err_list_del:
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
+	list_del(&i2c_priv->i2c_client_list_node);
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
+
+done:
 	return ret;
 }
 
@@ -361,11 +366,10 @@ static void atmel_ecc_remove(struct i2c_client *client)
 		return;
 	}
 
-	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
+	atmel_i2c_unregister_client(i2c_priv);
+	atmel_i2c_flush_queue();
 
-	spin_lock(&driver_data.i2c_list_lock);
-	list_del(&i2c_priv->i2c_client_list_node);
-	spin_unlock(&driver_data.i2c_list_lock);
+	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
 }
 
 #ifdef CONFIG_OF
@@ -398,21 +402,7 @@ static struct i2c_driver atmel_ecc_driver = {
 	.id_table	= atmel_ecc_id,
 };
 
-static int __init atmel_ecc_init(void)
-{
-	spin_lock_init(&driver_data.i2c_list_lock);
-	INIT_LIST_HEAD(&driver_data.i2c_client_list);
-	return i2c_add_driver(&atmel_ecc_driver);
-}
-
-static void __exit atmel_ecc_exit(void)
-{
-	atmel_i2c_flush_queue();
-	i2c_del_driver(&atmel_ecc_driver);
-}
-
-module_init(atmel_ecc_init);
-module_exit(atmel_ecc_exit);
+module_i2c_driver(atmel_ecc_driver);
 
 MODULE_AUTHOR("Tudor Ambarus");
 MODULE_DESCRIPTION("Microchip / Atmel ECC (I2C) driver");
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 0e275dbdc8c5..861af52d7a88 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -21,6 +21,12 @@
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
+struct atmel_i2c_client_mgmt atmel_i2c_mgmt = {
+	.i2c_list_lock = __SPIN_LOCK_UNLOCKED(atmel_i2c_mgmt.i2c_list_lock),
+	.i2c_client_list = LIST_HEAD_INIT(atmel_i2c_mgmt.i2c_client_list),
+};
+EXPORT_SYMBOL_GPL(atmel_i2c_mgmt);
+
 static const struct {
 	u8 value;
 	const char *error_text;
@@ -348,6 +354,15 @@ static int device_sanity_check(struct i2c_client *client)
 	return ret;
 }
 
+void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv)
+{
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
+	if (!list_empty(&i2c_priv->i2c_client_list_node))
+		list_del_init(&i2c_priv->i2c_client_list_node);
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
+}
+EXPORT_SYMBOL(atmel_i2c_unregister_client);
+
 int atmel_i2c_probe(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv;
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 72f04c15682f..43a0c1cfcd94 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -115,10 +115,11 @@ struct atmel_i2c_cmd {
 #define ECDH_PREFIX_MODE		0x00
 
 /* Used for binding tfm objects to i2c clients. */
-struct atmel_ecc_driver_data {
+struct atmel_i2c_client_mgmt {
 	struct list_head i2c_client_list;
 	spinlock_t i2c_list_lock;
 } ____cacheline_aligned;
+extern struct atmel_i2c_client_mgmt atmel_i2c_mgmt;
 
 /**
  * atmel_i2c_client_priv - i2c_client private data
@@ -189,4 +190,6 @@ void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid);
 int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 			    struct scatterlist *pubkey);
 
+void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv);
+
 #endif /* __ATMEL_I2C_H__ */
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index ed7d69bf6890..e6808c2bc891 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -169,10 +169,17 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 
 	ret = atmel_i2c_probe(client);
 	if (ret)
-		return ret;
+		goto done;
 
 	i2c_priv = i2c_get_clientdata(client);
 
+	/* add to client list */
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
+	list_add_tail(&i2c_priv->i2c_client_list_node,
+		      &atmel_i2c_mgmt.i2c_client_list);
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
+
+	/* register rng */
 	memset(&i2c_priv->hwrng, 0, sizeof(i2c_priv->hwrng));
 
 	i2c_priv->hwrng.name = dev_name(&client->dev);
@@ -183,15 +190,26 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 		i2c_priv->hwrng.quality = *quality;
 
 	ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
-	if (ret)
+	if (ret) {
 		dev_warn(&client->dev, "failed to register RNG (%d)\n", ret);
+		goto err_list_del;
+	}
 
 	ret = sysfs_create_group(&client->dev.kobj, &atmel_sha204a_groups);
 	if (ret) {
 		dev_err(&client->dev, "failed to register sysfs entry\n");
-		return ret;
+		goto err_list_del;
 	}
 
+	goto done;
+
+err_list_del:
+	sysfs_remove_group(&client->dev.kobj, &atmel_sha204a_groups);
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
+	list_del(&i2c_priv->i2c_client_list_node);
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
+
+done:
 	return ret;
 }
 
@@ -230,19 +248,7 @@ static struct i2c_driver atmel_sha204a_driver = {
 	.driver.of_match_table	= of_match_ptr(atmel_sha204a_dt_ids),
 };
 
-static int __init atmel_sha204a_init(void)
-{
-	return i2c_add_driver(&atmel_sha204a_driver);
-}
-
-static void __exit atmel_sha204a_exit(void)
-{
-	atmel_i2c_flush_queue();
-	i2c_del_driver(&atmel_sha204a_driver);
-}
-
-module_init(atmel_sha204a_init);
-module_exit(atmel_sha204a_exit);
+module_i2c_driver(atmel_sha204a_driver);
 
 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 MODULE_DESCRIPTION("Microchip / Atmel SHA204A (I2C) driver");
-- 
2.53.0

[PATCH 02/12] crypto: atmel - move capability-based client allocation into i2c core

[Lothar Rubusch]

Move the i2c client allocation logic from atmel-ecc into the shared
atmel-i2c core and extend it to support capability-based client
selection.

Introduce enum atmel_i2c_capability and add capability flags to
struct atmel_i2c_client_priv. Devices now advertise their supported
features during probe, allowing atmel_i2c_client_alloc() to select a
compatible client from the shared i2c client list.

The allocation logic continues to balance crypto transformation usage
across devices by selecting the client with the lowest tfm_count, but
is no longer limited to ECC-capable devices.

This centralizes shared client management in the common atmel-i2c core
and prepares the infrastructure for additional shared crypto features
across compatible Atmel devices.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     | 39 +++-------------------------------
 drivers/crypto/atmel-i2c.c     | 39 ++++++++++++++++++++++++++++++++++
 drivers/crypto/atmel-i2c.h     |  7 ++++++
 drivers/crypto/atmel-sha204a.c |  2 ++
 4 files changed, 51 insertions(+), 36 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index cba4238735cc..c63d30947bd7 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -200,41 +200,6 @@ static int atmel_ecdh_compute_shared_secret(struct kpp_request *req)
 	return ret;
 }
 
-static struct i2c_client *atmel_ecc_i2c_client_alloc(void)
-{
-	struct atmel_i2c_client_priv *i2c_priv, *min_i2c_priv = NULL;
-	struct i2c_client *client = ERR_PTR(-ENODEV);
-	int min_tfm_cnt = INT_MAX;
-	int tfm_cnt;
-
-	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
-
-	if (list_empty(&atmel_i2c_mgmt.i2c_client_list)) {
-		spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
-		return ERR_PTR(-ENODEV);
-	}
-
-	list_for_each_entry(i2c_priv, &atmel_i2c_mgmt.i2c_client_list,
-			    i2c_client_list_node) {
-		tfm_cnt = atomic_read(&i2c_priv->tfm_count);
-		if (tfm_cnt < min_tfm_cnt) {
-			min_tfm_cnt = tfm_cnt;
-			min_i2c_priv = i2c_priv;
-		}
-		if (!min_tfm_cnt)
-			break;
-	}
-
-	if (min_i2c_priv) {
-		atomic_inc(&min_i2c_priv->tfm_count);
-		client = min_i2c_priv->client;
-	}
-
-	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
-
-	return client;
-}
-
 static void atmel_ecc_i2c_client_free(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
@@ -249,7 +214,7 @@ static int atmel_ecdh_init_tfm(struct crypto_kpp *tfm)
 	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
 
 	ctx->curve_id = ECC_CURVE_NIST_P256;
-	ctx->client = atmel_ecc_i2c_client_alloc();
+	ctx->client = atmel_i2c_client_alloc(ATMEL_CAP_ECDH);
 	if (IS_ERR(ctx->client)) {
 		pr_err("tfm - i2c_client binding failed\n");
 		return PTR_ERR(ctx->client);
@@ -321,6 +286,8 @@ static int atmel_ecc_probe(struct i2c_client *client)
 
 	i2c_priv = i2c_get_clientdata(client);
 
+	i2c_priv->caps = BIT(ATMEL_CAP_ECDH);
+
 	/* add to client list */
 	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 	list_add_tail(&i2c_priv->i2c_client_list_node,
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 861af52d7a88..b7ee2ec37531 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -57,6 +57,45 @@ static void atmel_i2c_checksum(struct atmel_i2c_cmd *cmd)
 	*__crc16 = cpu_to_le16(bitrev16(crc16(0, data, len)));
 }
 
+struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap)
+{
+	struct atmel_i2c_client_priv *i2c_priv, *min_i2c_priv = NULL;
+	struct i2c_client *client = ERR_PTR(-ENODEV);
+	int min_tfm_cnt = INT_MAX;
+	int tfm_cnt;
+
+	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
+
+	if (list_empty(&atmel_i2c_mgmt.i2c_client_list)) {
+		spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
+		return ERR_PTR(-ENODEV);
+	}
+
+	list_for_each_entry(i2c_priv, &atmel_i2c_mgmt.i2c_client_list,
+			    i2c_client_list_node) {
+		if (!(i2c_priv->caps & BIT(cap)))
+			continue;
+
+		tfm_cnt = atomic_read(&i2c_priv->tfm_count);
+		if (tfm_cnt < min_tfm_cnt) {
+			min_tfm_cnt = tfm_cnt;
+			min_i2c_priv = i2c_priv;
+		}
+		if (!min_tfm_cnt)
+			break;
+	}
+
+	if (min_i2c_priv) {
+		atomic_inc(&min_i2c_priv->tfm_count);
+		client = min_i2c_priv->client;
+	}
+
+	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
+
+	return client;
+}
+EXPORT_SYMBOL(atmel_i2c_client_alloc);
+
 void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd)
 {
 	cmd->word_addr = COMMAND;
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 43a0c1cfcd94..70579b438256 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -115,6 +115,10 @@ struct atmel_i2c_cmd {
 #define ECDH_PREFIX_MODE		0x00
 
 /* Used for binding tfm objects to i2c clients. */
+enum atmel_i2c_capability {
+	ATMEL_CAP_ECDH = 0,
+};
+
 struct atmel_i2c_client_mgmt {
 	struct list_head i2c_client_list;
 	spinlock_t i2c_list_lock;
@@ -130,6 +134,7 @@ extern struct atmel_i2c_client_mgmt atmel_i2c_mgmt;
  * @wake_token_sz       : size in bytes of the wake_token
  * @tfm_count           : number of active crypto transformations on i2c client
  * @hwrng               : hold the hardware generated rng
+ * @caps                : feature capability of the particular driver
  *
  * Reads and writes from/to the i2c client are sequential. The first byte
  * transmitted to the device is treated as the byte size. Any attempt to send
@@ -146,6 +151,7 @@ struct atmel_i2c_client_priv {
 	size_t wake_token_sz;
 	atomic_t tfm_count ____cacheline_aligned;
 	struct hwrng hwrng;
+	u32 caps;
 };
 
 /**
@@ -190,6 +196,7 @@ void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid);
 int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 			    struct scatterlist *pubkey);
 
+struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap);
 void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv);
 
 #endif /* __ATMEL_I2C_H__ */
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index e6808c2bc891..ab758c9cd410 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -173,6 +173,8 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 
 	i2c_priv = i2c_get_clientdata(client);
 
+	i2c_priv->caps = 0;
+
 	/* add to client list */
 	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 	list_add_tail(&i2c_priv->i2c_client_list_node,
-- 
2.53.0

[PATCH 03/12] crypto: atmel - remove obsolete CONFIG_OF guard

[Lothar Rubusch]

Remove the CONFIG_OF preprocessor guard around the OF device match
table in atmel-ecc.

OF match tables are expected to be present unconditionally and the
MODULE_DEVICE_TABLE(of, ...) handling already accounts for
configurations where OF support is disabled. Keeping the additional
guard provides no benefit and only adds unnecessary conditional
compilation.

Also compact the match table formatting while touching the code.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index c63d30947bd7..0dede3707b73 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -339,18 +339,12 @@ static void atmel_ecc_remove(struct i2c_client *client)
 	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
 }
 
-#ifdef CONFIG_OF
 static const struct of_device_id atmel_ecc_dt_ids[] = {
-	{
-		.compatible = "atmel,atecc508a",
-	}, {
-		.compatible = "atmel,atecc608b",
-	}, {
-		/* sentinel */
-	}
+	{ .compatible = "atmel,atecc508a", },
+	{ .compatible = "atmel,atecc608b", },
+	{ }
 };
 MODULE_DEVICE_TABLE(of, atmel_ecc_dt_ids);
-#endif
 
 static const struct i2c_device_id atmel_ecc_id[] = {
 	{ "atecc508a" },
-- 
2.53.0

[PATCH 04/12] crypto: atmel - add per-device timing and match-data driven configuration

[Lothar Rubusch]

The ATSHA204(A) and ATECC device families define different maximum
command execution times in their datasheets. The current driver uses a
mixed set of timing constants, which can result in insufficient wait
times for some devices.

Introduce struct atmel_i2c_of_match_data to provide per-device timing
information through the device match tables. Store the match data in the
client private structure and pass the timing parameters to the command
initialization helpers instead of relying on global timing constants.

This allows the common atmel-i2c core to use device-specific command
timeouts for operations such as READ, RANDOM, GENKEY, and ECDH.

Also move the legacy hwrng quality information into the match data
structure to consolidate per-device configuration in a single place.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     | 32 +++++++++++++---
 drivers/crypto/atmel-i2c.c     | 29 ++++++++------
 drivers/crypto/atmel-i2c.h     | 36 ++++++++++++------
 drivers/crypto/atmel-sha204a.c | 69 ++++++++++++++++++++++++----------
 4 files changed, 120 insertions(+), 46 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index 0dede3707b73..7793f7b4e97e 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -76,6 +76,8 @@ static int atmel_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
 				 unsigned int len)
 {
 	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(ctx->client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
 	struct atmel_i2c_cmd *cmd;
 	void *public_key;
 	struct ecdh params;
@@ -112,7 +114,7 @@ static int atmel_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
 
 	ctx->do_fallback = false;
 
-	atmel_i2c_init_genkey_cmd(cmd, DATA_SLOT_2);
+	atmel_i2c_init_genkey_cmd(cmd, DATA_SLOT_2, &data->timings);
 
 	ret = atmel_i2c_send_receive(ctx->client, cmd);
 	if (ret)
@@ -164,6 +166,8 @@ static int atmel_ecdh_compute_shared_secret(struct kpp_request *req)
 {
 	struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
 	struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(ctx->client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
 	struct atmel_i2c_work_data *work_data;
 	gfp_t gfp;
 	int ret;
@@ -187,7 +191,7 @@ static int atmel_ecdh_compute_shared_secret(struct kpp_request *req)
 	work_data->ctx = ctx;
 	work_data->client = ctx->client;
 
-	ret = atmel_i2c_init_ecdh_cmd(&work_data->cmd, req->src);
+	ret = atmel_i2c_init_ecdh_cmd(&work_data->cmd, req->src, &data->timings);
 	if (ret)
 		goto free_work_data;
 
@@ -278,14 +282,22 @@ static struct kpp_alg atmel_ecdh_nist_p256 = {
 static int atmel_ecc_probe(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv;
+	const struct atmel_i2c_of_match_data *data;
 	int ret;
 
 	ret = atmel_i2c_probe(client);
 	if (ret)
 		goto done;
 
-	i2c_priv = i2c_get_clientdata(client);
+	data = device_get_match_data(&client->dev);
+	if (!data) {
+		dev_err(&client->dev, "no match data found via OF or ID table\n");
+		ret = -ENODEV;
+		goto done;
+	}
 
+	i2c_priv = i2c_get_clientdata(client);
+	i2c_priv->data = data;
 	i2c_priv->caps = BIT(ATMEL_CAP_ECDH);
 
 	/* add to client list */
@@ -339,9 +351,19 @@ static void atmel_ecc_remove(struct i2c_client *client)
 	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
 }
 
+static const struct atmel_i2c_of_match_data atecc508a_match_data = {
+	.timings = {
+		.max_exec_time_ecdh = 58,
+		.max_exec_time_genkey = 115,
+		.max_exec_time_random = 23,
+		.max_exec_time_read = 1,
+		.max_exec_time_write = 42,
+	},
+};
+
 static const struct of_device_id atmel_ecc_dt_ids[] = {
-	{ .compatible = "atmel,atecc508a", },
-	{ .compatible = "atmel,atecc608b", },
+	{ .compatible = "atmel,atecc508a", .data = &atecc508a_match_data, },
+	{ .compatible = "atmel,atecc608b", .data = &atecc508a_match_data, },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, atmel_ecc_dt_ids);
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index b7ee2ec37531..7fa7cf9ab3c1 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -96,7 +96,8 @@ struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap)
 }
 EXPORT_SYMBOL(atmel_i2c_client_alloc);
 
-void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd)
+void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
+				    const struct atmel_i2c_max_exec_timings *timings)
 {
 	cmd->word_addr = COMMAND;
 	cmd->opcode = OPCODE_READ;
@@ -110,12 +111,13 @@ void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd)
 
 	atmel_i2c_checksum(cmd);
 
-	cmd->msecs = MAX_EXEC_TIME_READ;
+	cmd->msecs = timings->max_exec_time_read;
 	cmd->rxsize = READ_RSP_SIZE;
 }
 EXPORT_SYMBOL(atmel_i2c_init_read_config_cmd);
 
-int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr)
+int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr,
+				const struct atmel_i2c_max_exec_timings *timings)
 {
 	if (addr >= OTP_ZONE_SIZE / 4)
 		return -EINVAL;
@@ -132,14 +134,15 @@ int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr)
 
 	atmel_i2c_checksum(cmd);
 
-	cmd->msecs = MAX_EXEC_TIME_READ;
+	cmd->msecs = timings->max_exec_time_read;
 	cmd->rxsize = READ_RSP_SIZE;
 
 	return 0;
 }
 EXPORT_SYMBOL(atmel_i2c_init_read_otp_cmd);
 
-void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd)
+void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
+			       const struct atmel_i2c_max_exec_timings *timings)
 {
 	cmd->word_addr = COMMAND;
 	cmd->opcode = OPCODE_RANDOM;
@@ -149,12 +152,13 @@ void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd)
 
 	atmel_i2c_checksum(cmd);
 
-	cmd->msecs = MAX_EXEC_TIME_RANDOM;
+	cmd->msecs = timings->max_exec_time_random;
 	cmd->rxsize = RANDOM_RSP_SIZE;
 }
 EXPORT_SYMBOL(atmel_i2c_init_random_cmd);
 
-void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid)
+void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
+			       const struct atmel_i2c_max_exec_timings *timings)
 {
 	cmd->word_addr = COMMAND;
 	cmd->count = GENKEY_COUNT;
@@ -165,13 +169,14 @@ void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid)
 
 	atmel_i2c_checksum(cmd);
 
-	cmd->msecs = MAX_EXEC_TIME_GENKEY;
+	cmd->msecs = timings->max_exec_time_genkey;
 	cmd->rxsize = GENKEY_RSP_SIZE;
 }
 EXPORT_SYMBOL(atmel_i2c_init_genkey_cmd);
 
 int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
-			    struct scatterlist *pubkey)
+			    struct scatterlist *pubkey,
+			    const struct atmel_i2c_max_exec_timings *timings)
 {
 	size_t copied;
 
@@ -196,7 +201,7 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 
 	atmel_i2c_checksum(cmd);
 
-	cmd->msecs = MAX_EXEC_TIME_ECDH;
+	cmd->msecs = timings->max_exec_time_ecdh;
 	cmd->rxsize = ECDH_RSP_SIZE;
 
 	return 0;
@@ -363,6 +368,8 @@ static inline size_t atmel_i2c_wake_token_sz(u32 bus_clk_rate)
 
 static int device_sanity_check(struct i2c_client *client)
 {
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
 	struct atmel_i2c_cmd *cmd;
 	int ret;
 
@@ -370,7 +377,7 @@ static int device_sanity_check(struct i2c_client *client)
 	if (!cmd)
 		return -ENOMEM;
 
-	atmel_i2c_init_read_config_cmd(cmd);
+	atmel_i2c_init_read_config_cmd(cmd, &data->timings);
 
 	ret = atmel_i2c_send_receive(client, cmd);
 	if (ret)
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 70579b438256..5224a62c16c9 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -57,6 +57,19 @@ struct atmel_i2c_cmd {
 	u16 rxsize;
 } __packed;
 
+struct atmel_i2c_max_exec_timings {
+	unsigned int max_exec_time_genkey;
+	unsigned int max_exec_time_ecdh;
+	unsigned int max_exec_time_random;
+	unsigned int max_exec_time_read;
+	unsigned int max_exec_time_write;
+};
+
+struct atmel_i2c_of_match_data {
+	const unsigned short *legacy_hwrng;
+	struct atmel_i2c_max_exec_timings timings;
+};
+
 /* Status/Error codes */
 #define STATUS_SIZE			0x04
 #define STATUS_NOERR			0x00
@@ -88,12 +101,6 @@ struct atmel_i2c_cmd {
 /* Wake Low duration */
 #define TWLO_USEC			60
 
-/* Command execution time (milliseconds) */
-#define MAX_EXEC_TIME_ECDH		58
-#define MAX_EXEC_TIME_GENKEY		115
-#define MAX_EXEC_TIME_READ		1
-#define MAX_EXEC_TIME_RANDOM		50
-
 /* Command opcode */
 #define OPCODE_ECDH			0x43
 #define OPCODE_GENKEY			0x40
@@ -135,6 +142,7 @@ extern struct atmel_i2c_client_mgmt atmel_i2c_mgmt;
  * @tfm_count           : number of active crypto transformations on i2c client
  * @hwrng               : hold the hardware generated rng
  * @caps                : feature capability of the particular driver
+ * @data                : preinitialized driver data
  *
  * Reads and writes from/to the i2c client are sequential. The first byte
  * transmitted to the device is treated as the byte size. Any attempt to send
@@ -152,6 +160,7 @@ struct atmel_i2c_client_priv {
 	atomic_t tfm_count ____cacheline_aligned;
 	struct hwrng hwrng;
 	u32 caps;
+	const struct atmel_i2c_of_match_data *data;
 };
 
 /**
@@ -189,12 +198,17 @@ void atmel_i2c_flush_queue(void);
 
 int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd);
 
-void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd);
-int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr);
-void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd);
-void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid);
+void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
+				    const struct atmel_i2c_max_exec_timings *timings);
+int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr,
+				const struct atmel_i2c_max_exec_timings *timings);
+void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
+			       const struct atmel_i2c_max_exec_timings *timings);
+void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
+			       const struct atmel_i2c_max_exec_timings *timings);
 int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
-			    struct scatterlist *pubkey);
+			    struct scatterlist *pubkey,
+			    const struct atmel_i2c_max_exec_timings *timings);
 
 struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap);
 void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv);
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index ab758c9cd410..febf9891b167 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -40,14 +40,15 @@ static void atmel_sha204a_rng_done(struct atmel_i2c_work_data *work_data,
 	atomic_dec(&i2c_priv->tfm_count);
 }
 
-static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *data,
+static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *buf,
 					      size_t max)
 {
-	struct atmel_i2c_client_priv *i2c_priv;
+	struct atmel_i2c_client_priv *i2c_priv = container_of(rng,
+							      struct atmel_i2c_client_priv,
+							      hwrng);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
 	struct atmel_i2c_work_data *work_data;
 
-	i2c_priv = container_of(rng, struct atmel_i2c_client_priv, hwrng);
-
 	/* keep maximum 1 asynchronous read in flight at any time */
 	if (!atomic_add_unless(&i2c_priv->tfm_count, 1, 1))
 		return 0;
@@ -55,7 +56,7 @@ static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *data,
 	if (rng->priv) {
 		work_data = (struct atmel_i2c_work_data *)rng->priv;
 		max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
-		memcpy(data, &work_data->cmd.data[RSP_DATA_IDX], max);
+		memcpy(buf, &work_data->cmd.data[RSP_DATA_IDX], max);
 		rng->priv = 0;
 	} else {
 		work_data = kmalloc_obj(*work_data, GFP_ATOMIC);
@@ -69,42 +70,45 @@ static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *data,
 		max = 0;
 	}
 
-	atmel_i2c_init_random_cmd(&work_data->cmd);
+	atmel_i2c_init_random_cmd(&work_data->cmd, &data->timings);
 	atmel_i2c_enqueue(work_data, atmel_sha204a_rng_done, rng);
 
 	return max;
 }
 
-static int atmel_sha204a_rng_read(struct hwrng *rng, void *data, size_t max,
+static int atmel_sha204a_rng_read(struct hwrng *rng, void *buf, size_t max,
 				  bool wait)
 {
-	struct atmel_i2c_client_priv *i2c_priv;
+	struct atmel_i2c_client_priv *i2c_priv = container_of(rng,
+							      struct atmel_i2c_client_priv,
+							      hwrng);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
 	struct atmel_i2c_cmd cmd;
 	int ret;
 
 	if (!wait)
-		return atmel_sha204a_rng_read_nonblocking(rng, data, max);
-
-	i2c_priv = container_of(rng, struct atmel_i2c_client_priv, hwrng);
+		return atmel_sha204a_rng_read_nonblocking(rng, buf, max);
 
-	atmel_i2c_init_random_cmd(&cmd);
+	atmel_i2c_init_random_cmd(&cmd, &data->timings);
 
 	ret = atmel_i2c_send_receive(i2c_priv->client, &cmd);
 	if (ret)
 		return ret;
 
 	max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
-	memcpy(data, &cmd.data[RSP_DATA_IDX], max);
+	memcpy(buf, &cmd.data[RSP_DATA_IDX], max);
 
 	return max;
 }
 
 static int atmel_sha204a_otp_read(struct i2c_client *client, u16 addr, u8 *otp)
 {
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
 	struct atmel_i2c_cmd cmd;
 	int ret;
 
-	ret = atmel_i2c_init_read_otp_cmd(&cmd, addr);
+	ret = atmel_i2c_init_read_otp_cmd(&cmd, addr, &data->timings);
 	if (ret < 0) {
 		dev_err(&client->dev, "failed, invalid otp address %04X\n",
 			addr);
@@ -164,6 +168,7 @@ static const struct attribute_group atmel_sha204a_groups = {
 static int atmel_sha204a_probe(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv;
+	const struct atmel_i2c_of_match_data *data;
 	const unsigned short *quality;
 	int ret;
 
@@ -171,8 +176,15 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 	if (ret)
 		goto done;
 
-	i2c_priv = i2c_get_clientdata(client);
+	data = device_get_match_data(&client->dev);
+	if (!data) {
+		dev_err(&client->dev, "no match data found via OF or ID table\n");
+		ret = -ENODEV;
+		goto done;
+	}
 
+	i2c_priv = i2c_get_clientdata(client);
+	i2c_priv->data = data;
 	i2c_priv->caps = 0;
 
 	/* add to client list */
@@ -187,7 +199,7 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 	i2c_priv->hwrng.name = dev_name(&client->dev);
 	i2c_priv->hwrng.read = atmel_sha204a_rng_read;
 
-	quality = i2c_get_match_data(client);
+	quality = i2c_priv->data->legacy_hwrng;
 	if (quality)
 		i2c_priv->hwrng.quality = *quality;
 
@@ -227,15 +239,34 @@ static void atmel_sha204a_remove(struct i2c_client *client)
 	kfree((void *)i2c_priv->hwrng.priv);
 }
 
+static const struct atmel_i2c_of_match_data atsha204_match_data = {
+	.timings = {
+		.max_exec_time_genkey = 43,
+		.max_exec_time_random = 50,
+		.max_exec_time_read = 4,
+		.max_exec_time_write = 42,
+	},
+	.legacy_hwrng = &atsha204_quality,
+};
+
+static const struct atmel_i2c_of_match_data atsha204a_match_data = {
+	.timings = {
+		.max_exec_time_genkey = 43,
+		.max_exec_time_random = 50,
+		.max_exec_time_read = 4,
+		.max_exec_time_write = 42,
+	},
+};
+
 static const struct of_device_id atmel_sha204a_dt_ids[] __maybe_unused = {
-	{ .compatible = "atmel,atsha204", .data = &atsha204_quality },
-	{ .compatible = "atmel,atsha204a", },
+	{ .compatible = "atmel,atsha204", .data = &atsha204_match_data, },
+	{ .compatible = "atmel,atsha204a", .data = &atsha204a_match_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, atmel_sha204a_dt_ids);
 
 static const struct i2c_device_id atmel_sha204a_id[] = {
-	{ "atsha204", (kernel_ulong_t)&atsha204_quality },
+	{ "atsha204" },
 	{ "atsha204a" },
 	{ /* sentinel */ }
 };
-- 
2.53.0

[PATCH 05/12] crypto: atmel - move RNG support into common i2c core

[Lothar Rubusch]

Move the hardware RNG implementation from atmel-sha204a into the
shared atmel-i2c core.

The ATSHA204(A) and ATECC devices provide compatible RANDOM commands
through the common Atmel I2C interface. Consolidate the RNG handling in
the core driver and provide a shared atmel_i2c_register_rng() helper for
registering the hwrng device.

This removes duplicated RNG code from atmel-sha204a and enables RNG
support for other compatible Atmel devices, including the ECC family.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     |  12 ++++
 drivers/crypto/atmel-i2c.c     |  93 ++++++++++++++++++++++++++
 drivers/crypto/atmel-i2c.h     |   4 +-
 drivers/crypto/atmel-sha204a.c | 115 +++++----------------------------
 4 files changed, 123 insertions(+), 101 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index 7793f7b4e97e..67fa5975fa7f 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -306,6 +306,13 @@ static int atmel_ecc_probe(struct i2c_client *client)
 		      &atmel_i2c_mgmt.i2c_client_list);
 	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 
+	/* register rng */
+	ret = atmel_i2c_register_rng(i2c_priv, &client->dev);
+	if (ret) {
+		dev_err(&client->dev, "failed to register hw_random\n");
+		goto err_list_del;
+	}
+
 	/* register algorithms */
 	ret = crypto_register_kpp(&atmel_ecdh_nist_p256);
 	if (ret) {
@@ -349,6 +356,11 @@ static void atmel_ecc_remove(struct i2c_client *client)
 	atmel_i2c_flush_queue();
 
 	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
+
+	if (i2c_priv->hwrng.priv) {
+		kfree((void *)i2c_priv->hwrng.priv);
+		i2c_priv->hwrng.priv = 0;
+	}
 }
 
 static const struct atmel_i2c_of_match_data atecc508a_match_data = {
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 7fa7cf9ab3c1..d451017171d8 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -208,6 +208,99 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 }
 EXPORT_SYMBOL(atmel_i2c_init_ecdh_cmd);
 
+static void atmel_i2c_rng_done(struct atmel_i2c_work_data *work_data,
+			       void *areq, int status)
+{
+	struct atmel_i2c_client_priv *i2c_priv = work_data->ctx;
+	struct hwrng *rng = areq;
+
+	if (status)
+		dev_warn_ratelimited(&i2c_priv->client->dev,
+				     "i2c transaction failed (%d)\n",
+				     status);
+
+	rng->priv = (unsigned long)work_data;
+	atomic_dec(&i2c_priv->tfm_count);
+}
+
+static int atmel_i2c_rng_read_nonblocking(struct hwrng *rng, void *buf,
+					  size_t max)
+{
+	struct atmel_i2c_client_priv *i2c_priv = container_of(rng,
+							      struct atmel_i2c_client_priv,
+							      hwrng);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	struct atmel_i2c_work_data *work_data;
+
+	/* keep maximum 1 asynchronous read in flight at any time */
+	if (!atomic_add_unless(&i2c_priv->tfm_count, 1, 1))
+		return 0;
+
+	if (rng->priv) {
+		work_data = (struct atmel_i2c_work_data *)rng->priv;
+		max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
+		memcpy(buf, &work_data->cmd.data[RSP_DATA_IDX], max);
+		rng->priv = 0;
+	} else {
+		work_data = kmalloc_obj(*work_data, GFP_ATOMIC);
+		if (!work_data) {
+			atomic_dec(&i2c_priv->tfm_count);
+			return -ENOMEM;
+		}
+		work_data->ctx = i2c_priv;
+		work_data->client = i2c_priv->client;
+
+		max = 0;
+	}
+
+	atmel_i2c_init_random_cmd(&work_data->cmd, &data->timings);
+	atmel_i2c_enqueue(work_data, atmel_i2c_rng_done, rng);
+
+	return max;
+}
+
+static int atmel_i2c_rng_read(struct hwrng *rng, void *buf, size_t max,
+			      bool wait)
+{
+	struct atmel_i2c_client_priv *i2c_priv = container_of(rng,
+							      struct atmel_i2c_client_priv,
+							      hwrng);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	struct atmel_i2c_cmd cmd;
+	int ret;
+
+	if (!wait)
+		return atmel_i2c_rng_read_nonblocking(rng, buf, max);
+
+	atmel_i2c_init_random_cmd(&cmd, &data->timings);
+
+	ret = atmel_i2c_send_receive(i2c_priv->client, &cmd);
+	if (ret)
+		return ret;
+
+	max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
+	memcpy(buf, &cmd.data[RSP_DATA_IDX], max);
+
+	return max;
+}
+
+int atmel_i2c_register_rng(struct atmel_i2c_client_priv *i2c_priv,
+			   struct device *dev)
+{
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+
+	memset(&i2c_priv->hwrng, 0, sizeof(i2c_priv->hwrng));
+
+	i2c_priv->hwrng.name = dev_name(dev);
+	i2c_priv->hwrng.read = atmel_i2c_rng_read;
+
+	if (data->needs_legacy_hwrng)
+		i2c_priv->hwrng.quality = data->needs_legacy_hwrng;
+
+	return devm_hwrng_register(dev, &i2c_priv->hwrng);
+}
+EXPORT_SYMBOL(atmel_i2c_register_rng);
+
 /*
  * After wake and after execution of a command, there will be error, status, or
  * result bytes in the device's output register that can be retrieved by the
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 5224a62c16c9..5f6c9ff0cf64 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -66,7 +66,7 @@ struct atmel_i2c_max_exec_timings {
 };
 
 struct atmel_i2c_of_match_data {
-	const unsigned short *legacy_hwrng;
+	const unsigned short needs_legacy_hwrng;
 	struct atmel_i2c_max_exec_timings timings;
 };
 
@@ -209,6 +209,8 @@ void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
 int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 			    struct scatterlist *pubkey,
 			    const struct atmel_i2c_max_exec_timings *timings);
+int atmel_i2c_register_rng(struct atmel_i2c_client_priv *i2c_priv,
+			   struct device *dev);
 
 struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap);
 void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv);
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index febf9891b167..ae24d8fbabf9 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -19,88 +19,6 @@
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
-/*
- * According to review by Bill Cox [1], the ATSHA204 has very low entropy.
- * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
- */
-static const unsigned short atsha204_quality = 1;
-
-static void atmel_sha204a_rng_done(struct atmel_i2c_work_data *work_data,
-				   void *areq, int status)
-{
-	struct atmel_i2c_client_priv *i2c_priv = work_data->ctx;
-	struct hwrng *rng = areq;
-
-	if (status)
-		dev_warn_ratelimited(&i2c_priv->client->dev,
-				     "i2c transaction failed (%d)\n",
-				     status);
-
-	rng->priv = (unsigned long)work_data;
-	atomic_dec(&i2c_priv->tfm_count);
-}
-
-static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *buf,
-					      size_t max)
-{
-	struct atmel_i2c_client_priv *i2c_priv = container_of(rng,
-							      struct atmel_i2c_client_priv,
-							      hwrng);
-	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
-	struct atmel_i2c_work_data *work_data;
-
-	/* keep maximum 1 asynchronous read in flight at any time */
-	if (!atomic_add_unless(&i2c_priv->tfm_count, 1, 1))
-		return 0;
-
-	if (rng->priv) {
-		work_data = (struct atmel_i2c_work_data *)rng->priv;
-		max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
-		memcpy(buf, &work_data->cmd.data[RSP_DATA_IDX], max);
-		rng->priv = 0;
-	} else {
-		work_data = kmalloc_obj(*work_data, GFP_ATOMIC);
-		if (!work_data) {
-			atomic_dec(&i2c_priv->tfm_count);
-			return -ENOMEM;
-		}
-		work_data->ctx = i2c_priv;
-		work_data->client = i2c_priv->client;
-
-		max = 0;
-	}
-
-	atmel_i2c_init_random_cmd(&work_data->cmd, &data->timings);
-	atmel_i2c_enqueue(work_data, atmel_sha204a_rng_done, rng);
-
-	return max;
-}
-
-static int atmel_sha204a_rng_read(struct hwrng *rng, void *buf, size_t max,
-				  bool wait)
-{
-	struct atmel_i2c_client_priv *i2c_priv = container_of(rng,
-							      struct atmel_i2c_client_priv,
-							      hwrng);
-	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
-	struct atmel_i2c_cmd cmd;
-	int ret;
-
-	if (!wait)
-		return atmel_sha204a_rng_read_nonblocking(rng, buf, max);
-
-	atmel_i2c_init_random_cmd(&cmd, &data->timings);
-
-	ret = atmel_i2c_send_receive(i2c_priv->client, &cmd);
-	if (ret)
-		return ret;
-
-	max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
-	memcpy(buf, &cmd.data[RSP_DATA_IDX], max);
-
-	return max;
-}
-
 static int atmel_sha204a_otp_read(struct i2c_client *client, u16 addr, u8 *otp)
 {
 	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
@@ -169,7 +87,6 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv;
 	const struct atmel_i2c_of_match_data *data;
-	const unsigned short *quality;
 	int ret;
 
 	ret = atmel_i2c_probe(client);
@@ -193,25 +110,16 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 		      &atmel_i2c_mgmt.i2c_client_list);
 	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 
-	/* register rng */
-	memset(&i2c_priv->hwrng, 0, sizeof(i2c_priv->hwrng));
-
-	i2c_priv->hwrng.name = dev_name(&client->dev);
-	i2c_priv->hwrng.read = atmel_sha204a_rng_read;
-
-	quality = i2c_priv->data->legacy_hwrng;
-	if (quality)
-		i2c_priv->hwrng.quality = *quality;
-
-	ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
+	ret = sysfs_create_group(&client->dev.kobj, &atmel_sha204a_groups);
 	if (ret) {
-		dev_warn(&client->dev, "failed to register RNG (%d)\n", ret);
+		dev_err(&client->dev, "failed to register sysfs entry\n");
 		goto err_list_del;
 	}
 
-	ret = sysfs_create_group(&client->dev.kobj, &atmel_sha204a_groups);
+	/* register rng */
+	ret = atmel_i2c_register_rng(i2c_priv, &client->dev);
 	if (ret) {
-		dev_err(&client->dev, "failed to register sysfs entry\n");
+		dev_err(&client->dev, "failed to register hw_random\n");
 		goto err_list_del;
 	}
 
@@ -234,9 +142,12 @@ static void atmel_sha204a_remove(struct i2c_client *client)
 	devm_hwrng_unregister(&client->dev, &i2c_priv->hwrng);
 	atmel_i2c_flush_queue();
 
-	sysfs_remove_group(&client->dev.kobj, &atmel_sha204a_groups);
+	if (i2c_priv->hwrng.priv) {
+		kfree((void *)i2c_priv->hwrng.priv);
+		i2c_priv->hwrng.priv = 0;
+	}
 
-	kfree((void *)i2c_priv->hwrng.priv);
+	sysfs_remove_group(&client->dev.kobj, &atmel_sha204a_groups);
 }
 
 static const struct atmel_i2c_of_match_data atsha204_match_data = {
@@ -246,7 +157,11 @@ static const struct atmel_i2c_of_match_data atsha204_match_data = {
 		.max_exec_time_read = 4,
 		.max_exec_time_write = 42,
 	},
-	.legacy_hwrng = &atsha204_quality,
+	/*
+	 * According to review by Bill Cox [1], the ATSHA204 has very low entropy.
+	 * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
+	 */
+	.needs_legacy_hwrng = 1,
 };
 
 static const struct atmel_i2c_of_match_data atsha204a_match_data = {
-- 
2.53.0

[PATCH 06/12] crypto: atmel - move EEPROM access support into common i2c core

[Lothar Rubusch]

Move EEPROM read support from atmel-sha204a and atmel-ecc into the
shared atmel-i2c core and provide a generic interface for accessing
EEPROM zones on compatible Atmel devices.

Introduce enum atmel_i2c_eeprom_zones together with per-device EEPROM
zone sizing in struct atmel_i2c_of_match_data. Add common helpers for
EEPROM readout and sysfs formatting, and convert existing OTP sysfs
handling to use the shared infrastructure.

This removes duplicated EEPROM access logic from individual drivers and
extends support to ECC devices. The common implementation supports
CONFIG, OTP, and DATA zones using device-specific layout information
supplied via match data tables.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     |  36 ++++++++
 drivers/crypto/atmel-i2c.c     | 153 +++++++++++++++++++++++++--------
 drivers/crypto/atmel-i2c.h     |  30 +++----
 drivers/crypto/atmel-sha204a.c |  65 ++++----------
 4 files changed, 186 insertions(+), 98 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index 67fa5975fa7f..b5f2d44ec74c 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -23,6 +23,22 @@
 #include <crypto/kpp.h>
 #include "atmel-i2c.h"
 
+static ssize_t otp_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_OTP_ZONE);
+}
+static DEVICE_ATTR_RO(otp);
+
+static struct attribute *atmel_ecc508a_attrs[] = {
+	&dev_attr_otp.attr,
+	NULL
+};
+
+static const struct attribute_group atmel_ecc508a_groups = {
+	.name = "atecc508a",
+	.attrs = atmel_ecc508a_attrs,
+};
+
 /**
  * struct atmel_ecdh_ctx - transformation context
  * @client     : pointer to i2c client device
@@ -306,6 +322,18 @@ static int atmel_ecc_probe(struct i2c_client *client)
 		      &atmel_i2c_mgmt.i2c_client_list);
 	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 
+	/* EEPROM read out */
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		ret = -ENODEV;
+		goto err_list_del;
+	}
+
+	ret = sysfs_create_group(&client->dev.kobj, &atmel_ecc508a_groups);
+	if (ret) {
+		dev_err(&client->dev, "failed to register sysfs entry\n");
+		goto err_list_del;
+	}
+
 	/* register rng */
 	ret = atmel_i2c_register_rng(i2c_priv, &client->dev);
 	if (ret) {
@@ -326,6 +354,7 @@ static int atmel_ecc_probe(struct i2c_client *client)
 	goto done;
 
 err_list_del:
+	sysfs_remove_group(&client->dev.kobj, &atmel_ecc508a_groups);
 	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 	list_del(&i2c_priv->i2c_client_list_node);
 	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
@@ -361,6 +390,8 @@ static void atmel_ecc_remove(struct i2c_client *client)
 		kfree((void *)i2c_priv->hwrng.priv);
 		i2c_priv->hwrng.priv = 0;
 	}
+
+	sysfs_remove_group(&client->dev.kobj, &atmel_ecc508a_groups);
 }
 
 static const struct atmel_i2c_of_match_data atecc508a_match_data = {
@@ -371,6 +402,11 @@ static const struct atmel_i2c_of_match_data atecc508a_match_data = {
 		.max_exec_time_read = 1,
 		.max_exec_time_write = 42,
 	},
+	.eeprom_zone_size = {
+		[ATMEL_EEPROM_CONFIG_ZONE] = 128,
+		[ATMEL_EEPROM_OTP_ZONE] = 64,
+		[ATMEL_EEPROM_DATA_ZONE] = 1208
+	},
 };
 
 static const struct of_device_id atmel_ecc_dt_ids[] = {
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index d451017171d8..26863573a10f 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -21,6 +21,15 @@
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
+#define ATMEL_I2C_COMMAND			0x03 /* packet function */
+
+/* Command opcode */
+#define ATMEL_I2C_OPCODE_ECDH			0x43
+#define ATMEL_I2C_OPCODE_GENKEY			0x40
+#define ATMEL_I2C_OPCODE_READ			0x02
+#define ATMEL_I2C_OPCODE_RANDOM			0x1b
+#define ATMEL_I2C_OPCODE_WRITE			0x12
+
 struct atmel_i2c_client_mgmt atmel_i2c_mgmt = {
 	.i2c_list_lock = __SPIN_LOCK_UNLOCKED(atmel_i2c_mgmt.i2c_list_lock),
 	.i2c_client_list = LIST_HEAD_INIT(atmel_i2c_mgmt.i2c_client_list),
@@ -96,56 +105,55 @@ struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap)
 }
 EXPORT_SYMBOL(atmel_i2c_client_alloc);
 
-void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
-				    const struct atmel_i2c_max_exec_timings *timings)
+static int atmel_i2c_init_read_eeprom_cmd(struct atmel_i2c_cmd *cmd, u16 addr,
+					  enum atmel_i2c_eeprom_zones zone,
+					  const struct atmel_i2c_of_match_data *data)
 {
-	cmd->word_addr = COMMAND;
-	cmd->opcode = OPCODE_READ;
-	/*
-	 * Read the word from Configuration zone that contains the lock bytes
-	 * (UserExtra, Selector, LockValue, LockConfig).
-	 */
-	cmd->param1 = CONFIGURATION_ZONE;
-	cmd->param2 = cpu_to_le16(DEVICE_LOCK_ADDR);
-	cmd->count = READ_COUNT;
+	const struct atmel_i2c_max_exec_timings *timings = &data->timings;
+	size_t zone_size = data->eeprom_zone_size[zone];
+
+	if (addr > zone_size)
+		return -EINVAL;
+
+	cmd->word_addr = ATMEL_I2C_COMMAND;
+	cmd->opcode = ATMEL_I2C_OPCODE_READ;
+	cmd->param1 = zone;
+	cmd->param2 = cpu_to_le16(addr);
+	cmd->count = ATMEL_I2C_READ_COUNT;
 
 	atmel_i2c_checksum(cmd);
 
 	cmd->msecs = timings->max_exec_time_read;
-	cmd->rxsize = READ_RSP_SIZE;
+	cmd->rxsize = ATMEL_I2C_READ_RSP_SIZE;
+
+	return 0;
 }
-EXPORT_SYMBOL(atmel_i2c_init_read_config_cmd);
 
-int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr,
-				const struct atmel_i2c_max_exec_timings *timings)
+void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
+				    const struct atmel_i2c_max_exec_timings *timings)
 {
-	if (addr >= OTP_ZONE_SIZE / 4)
-		return -EINVAL;
-
-	cmd->word_addr = COMMAND;
-	cmd->opcode = OPCODE_READ;
+	cmd->word_addr = ATMEL_I2C_COMMAND;
+	cmd->opcode = ATMEL_I2C_OPCODE_READ;
 	/*
-	 * Read the word from OTP zone that may contain e.g. serial
-	 * numbers or similar if persistently pre-initialized and locked
+	 * Read the word from Configuration zone that contains the lock bytes
+	 * (UserExtra, Selector, LockValue, LockConfig).
 	 */
-	cmd->param1 = OTP_ZONE;
-	cmd->param2 = cpu_to_le16(addr);
-	cmd->count = READ_COUNT;
+	cmd->param1 = CONFIGURATION_ZONE;
+	cmd->param2 = cpu_to_le16(DEVICE_LOCK_ADDR);
+	cmd->count = ATMEL_I2C_READ_COUNT;
 
 	atmel_i2c_checksum(cmd);
 
 	cmd->msecs = timings->max_exec_time_read;
-	cmd->rxsize = READ_RSP_SIZE;
-
-	return 0;
+	cmd->rxsize = ATMEL_I2C_READ_RSP_SIZE;
 }
-EXPORT_SYMBOL(atmel_i2c_init_read_otp_cmd);
+EXPORT_SYMBOL(atmel_i2c_init_read_config_cmd);
 
 void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
 			       const struct atmel_i2c_max_exec_timings *timings)
 {
-	cmd->word_addr = COMMAND;
-	cmd->opcode = OPCODE_RANDOM;
+	cmd->word_addr = ATMEL_I2C_COMMAND;
+	cmd->opcode = ATMEL_I2C_OPCODE_RANDOM;
 	cmd->param1 = 0;
 	cmd->param2 = 0;
 	cmd->count = RANDOM_COUNT;
@@ -160,9 +168,9 @@ EXPORT_SYMBOL(atmel_i2c_init_random_cmd);
 void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
 			       const struct atmel_i2c_max_exec_timings *timings)
 {
-	cmd->word_addr = COMMAND;
+	cmd->word_addr = ATMEL_I2C_COMMAND;
 	cmd->count = GENKEY_COUNT;
-	cmd->opcode = OPCODE_GENKEY;
+	cmd->opcode = ATMEL_I2C_OPCODE_GENKEY;
 	cmd->param1 = GENKEY_MODE_PRIVATE;
 	/* a random private key will be generated and stored in slot keyID */
 	cmd->param2 = cpu_to_le16(keyid);
@@ -180,9 +188,9 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 {
 	size_t copied;
 
-	cmd->word_addr = COMMAND;
+	cmd->word_addr = ATMEL_I2C_COMMAND;
 	cmd->count = ECDH_COUNT;
-	cmd->opcode = OPCODE_ECDH;
+	cmd->opcode = ATMEL_I2C_OPCODE_ECDH;
 	cmd->param1 = ECDH_PREFIX_MODE;
 	/* private key slot */
 	cmd->param2 = cpu_to_le16(DATA_SLOT_2);
@@ -301,6 +309,81 @@ int atmel_i2c_register_rng(struct atmel_i2c_client_priv *i2c_priv,
 }
 EXPORT_SYMBOL(atmel_i2c_register_rng);
 
+static int atmel_i2c_eeprom_read(struct i2c_client *client, u16 addr,
+				 enum atmel_i2c_eeprom_zones zone, u8 *buf)
+{
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	struct atmel_i2c_cmd *cmd;
+	int ret = -1;
+
+	cmd = kmalloc_obj(*cmd);
+	if (!cmd)
+		return -ENOMEM;
+
+	ret = atmel_i2c_init_read_eeprom_cmd(cmd, addr, zone, data);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed, invalid eeprom address %04X\n",
+			addr);
+		goto err;
+	}
+
+	ret = atmel_i2c_send_receive(client, cmd);
+	if (ret)
+		goto err;
+
+	if (cmd->data[0] == 0xff) {
+		dev_err(&client->dev, "failed, device not ready\n");
+		ret = -EINVAL;
+		goto err;
+	}
+
+	memcpy(buf, cmd->data + RSP_DATA_IDX, 4);
+
+err:
+	kfree(cmd);
+	return ret;
+}
+
+ssize_t atmel_i2c_eeprom_display(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf,
+				 enum atmel_i2c_eeprom_zones zone)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	const struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	const size_t *eeprom = data->eeprom_zone_size;
+	u16 block_addr;
+	u8 *eeprom_buf;
+	ssize_t len = 0;
+	int i, ret = 0;
+
+	eeprom_buf = kcalloc(eeprom[zone], sizeof(*eeprom_buf), GFP_KERNEL);
+	if (!eeprom_buf)
+		return -ENOMEM;
+
+	for (block_addr = 0; block_addr < eeprom[zone] / 4; block_addr++) {
+		ret = atmel_i2c_eeprom_read(client, block_addr, zone,
+					    eeprom_buf + block_addr * 4);
+		if (ret < 0) {
+			dev_err(dev, "failed to read %s zone\n",
+				zone == ATMEL_EEPROM_CONFIG_ZONE ? "CONFIG"
+				: (zone == ATMEL_EEPROM_OTP_ZONE ? "OTP" : "DATA"));
+			goto err;
+		}
+	}
+
+	for (i = 0; i < eeprom[zone]; i++)
+		len += sysfs_emit_at(buf, len, "%02X", eeprom_buf[i]);
+	len += sysfs_emit_at(buf, len, "\n");
+	ret = len;
+err:
+	kfree(eeprom_buf);
+	return ret;
+}
+EXPORT_SYMBOL(atmel_i2c_eeprom_display);
+
 /*
  * After wake and after execution of a command, there will be error, status, or
  * result bytes in the device's output register that can be retrieved by the
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 5f6c9ff0cf64..e30e0c417de2 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -12,7 +12,6 @@
 
 #define ATMEL_ECC_PRIORITY		300
 
-#define COMMAND				0x03 /* packet function */
 #define SLEEP_TOKEN			0x01
 #define WAKE_TOKEN_MAX_SIZE		8
 
@@ -30,7 +29,7 @@
 #define ECDH_RSP_SIZE			(32 + CMD_OVERHEAD_SIZE)
 #define GENKEY_RSP_SIZE			(ATMEL_ECC_PUBKEY_SIZE + \
 					 CMD_OVERHEAD_SIZE)
-#define READ_RSP_SIZE			(4 + CMD_OVERHEAD_SIZE)
+#define ATMEL_I2C_READ_RSP_SIZE		(4 + CMD_OVERHEAD_SIZE)
 #define RANDOM_RSP_SIZE			(32 + CMD_OVERHEAD_SIZE)
 #define MAX_RSP_SIZE			GENKEY_RSP_SIZE
 
@@ -57,6 +56,13 @@ struct atmel_i2c_cmd {
 	u16 rxsize;
 } __packed;
 
+/* Definitions for eeprom organization */
+enum atmel_i2c_eeprom_zones {
+	ATMEL_EEPROM_CONFIG_ZONE = 0,
+	ATMEL_EEPROM_OTP_ZONE = 1,
+	ATMEL_EEPROM_DATA_ZONE = 2,
+};
+
 struct atmel_i2c_max_exec_timings {
 	unsigned int max_exec_time_genkey;
 	unsigned int max_exec_time_ecdh;
@@ -68,6 +74,7 @@ struct atmel_i2c_max_exec_timings {
 struct atmel_i2c_of_match_data {
 	const unsigned short needs_legacy_hwrng;
 	struct atmel_i2c_max_exec_timings timings;
+	size_t eeprom_zone_size[3]; /* all atmel devices have three zones */
 };
 
 /* Status/Error codes */
@@ -77,10 +84,6 @@ struct atmel_i2c_of_match_data {
 
 /* Definitions for eeprom organization */
 #define CONFIGURATION_ZONE		0
-#define OTP_ZONE			1
-
-/* Definitions for eeprom zone sizes */
-#define OTP_ZONE_SIZE			64
 
 /* Definitions for Indexes common to all commands */
 #define RSP_DATA_IDX			1 /* buffer index of data in response */
@@ -101,14 +104,8 @@ struct atmel_i2c_of_match_data {
 /* Wake Low duration */
 #define TWLO_USEC			60
 
-/* Command opcode */
-#define OPCODE_ECDH			0x43
-#define OPCODE_GENKEY			0x40
-#define OPCODE_READ			0x02
-#define OPCODE_RANDOM			0x1b
-
 /* Definitions for the READ Command */
-#define READ_COUNT			7
+#define ATMEL_I2C_READ_COUNT		7
 
 /* Definitions for the RANDOM Command */
 #define RANDOM_COUNT			7
@@ -200,8 +197,6 @@ int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
 
 void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
 				    const struct atmel_i2c_max_exec_timings *timings);
-int atmel_i2c_init_read_otp_cmd(struct atmel_i2c_cmd *cmd, u16 addr,
-				const struct atmel_i2c_max_exec_timings *timings);
 void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
 			       const struct atmel_i2c_max_exec_timings *timings);
 void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
@@ -212,6 +207,11 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 int atmel_i2c_register_rng(struct atmel_i2c_client_priv *i2c_priv,
 			   struct device *dev);
 
+ssize_t atmel_i2c_eeprom_display(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf,
+				 enum atmel_i2c_eeprom_zones zone);
+
 struct i2c_client *atmel_i2c_client_alloc(enum atmel_i2c_capability cap);
 void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv);
 
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index ae24d8fbabf9..4f10e826e675 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -19,57 +19,10 @@
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
-static int atmel_sha204a_otp_read(struct i2c_client *client, u16 addr, u8 *otp)
-{
-	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
-	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
-	struct atmel_i2c_cmd cmd;
-	int ret;
-
-	ret = atmel_i2c_init_read_otp_cmd(&cmd, addr, &data->timings);
-	if (ret < 0) {
-		dev_err(&client->dev, "failed, invalid otp address %04X\n",
-			addr);
-		return ret;
-	}
-
-	ret = atmel_i2c_send_receive(client, &cmd);
-	if (ret < 0) {
-		dev_err(&client->dev, "failed to read otp at %04X\n", addr);
-		return ret;
-	}
-
-	if (cmd.data[0] == 0xff) {
-		dev_err(&client->dev, "failed, device not ready\n");
-		return -EIO;
-	}
-
-	memcpy(otp, cmd.data+1, 4);
-
-	return ret;
-}
-
 static ssize_t otp_show(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
-	u16 addr;
-	u8 otp[OTP_ZONE_SIZE];
-	struct i2c_client *client = to_i2c_client(dev);
-	ssize_t len = 0;
-	int i, ret;
-
-	for (addr = 0; addr < OTP_ZONE_SIZE / 4; addr++) {
-		ret = atmel_sha204a_otp_read(client, addr, otp + addr * 4);
-		if (ret < 0) {
-			dev_err(dev, "failed to read otp zone\n");
-			return ret;
-		}
-	}
-
-	for (i = 0; i < OTP_ZONE_SIZE; i++)
-		len += sysfs_emit_at(buf, len, "%02X", otp[i]);
-	len += sysfs_emit_at(buf, len, "\n");
-	return len;
+	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_OTP_ZONE);
 }
 static DEVICE_ATTR_RO(otp);
 
@@ -110,6 +63,12 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 		      &atmel_i2c_mgmt.i2c_client_list);
 	spin_unlock(&atmel_i2c_mgmt.i2c_list_lock);
 
+	/* EEPROM read out */
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		ret = -ENODEV;
+		goto err_list_del;
+	}
+
 	ret = sysfs_create_group(&client->dev.kobj, &atmel_sha204a_groups);
 	if (ret) {
 		dev_err(&client->dev, "failed to register sysfs entry\n");
@@ -157,6 +116,11 @@ static const struct atmel_i2c_of_match_data atsha204_match_data = {
 		.max_exec_time_read = 4,
 		.max_exec_time_write = 42,
 	},
+	.eeprom_zone_size = {
+		[ATMEL_EEPROM_CONFIG_ZONE] = 88,
+		[ATMEL_EEPROM_OTP_ZONE] = 64,
+		[ATMEL_EEPROM_DATA_ZONE] = 512
+	},
 	/*
 	 * According to review by Bill Cox [1], the ATSHA204 has very low entropy.
 	 * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
@@ -171,6 +135,11 @@ static const struct atmel_i2c_of_match_data atsha204a_match_data = {
 		.max_exec_time_read = 4,
 		.max_exec_time_write = 42,
 	},
+	.eeprom_zone_size = {
+		[ATMEL_EEPROM_CONFIG_ZONE] = 88,
+		[ATMEL_EEPROM_OTP_ZONE] = 64,
+		[ATMEL_EEPROM_DATA_ZONE] = 512
+	},
 };
 
 static const struct of_device_id atmel_sha204a_dt_ids[] __maybe_unused = {
-- 
2.53.0

[PATCH 07/12] crypto: atmel - expose CONFIG zone through sysfs

[Lothar Rubusch]

Expose the CONFIG EEPROM zone through a read-only sysfs attribute for
Atmel I2C crypto devices.

The CONFIG zone contains device configuration state, including slot
configuration and lock status, which is useful for debugging and
verifying provisioning state.

Reuse the generic EEPROM display helper provided by the Atmel I2C core
driver to expose the CONFIG zone for both SHA204A and ECC devices.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     | 7 +++++++
 drivers/crypto/atmel-sha204a.c | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index b5f2d44ec74c..f08fdf284b60 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -23,6 +23,12 @@
 #include <crypto/kpp.h>
 #include "atmel-i2c.h"
 
+static ssize_t config_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_CONFIG_ZONE);
+}
+static DEVICE_ATTR_ADMIN_RO(config);
+
 static ssize_t otp_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_OTP_ZONE);
@@ -30,6 +36,7 @@ static ssize_t otp_show(struct device *dev, struct device_attribute *attr, char
 static DEVICE_ATTR_RO(otp);
 
 static struct attribute *atmel_ecc508a_attrs[] = {
+	&dev_attr_config.attr,
 	&dev_attr_otp.attr,
 	NULL
 };
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 4f10e826e675..341554b7b7a2 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -19,6 +19,12 @@
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
+static ssize_t config_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_CONFIG_ZONE);
+}
+static DEVICE_ATTR_ADMIN_RO(config);
+
 static ssize_t otp_show(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
@@ -27,6 +33,7 @@ static ssize_t otp_show(struct device *dev,
 static DEVICE_ATTR_RO(otp);
 
 static struct attribute *atmel_sha204a_attrs[] = {
+	&dev_attr_config.attr,
 	&dev_attr_otp.attr,
 	NULL
 };
-- 
2.53.0

[PATCH 08/12] crypto: atmel - move device sanity check to core driver

[Lothar Rubusch]

Move the device sanity check implementation into the shared Atmel
I2C core driver and reuse the generic EEPROM access helpers for
reading the CONFIG zone lock state.

This removes duplicate CONFIG zone handling and consolidates common
response index and lock state definitions under the Atmel I2C core
namespace.

Update both SHA204A and ECC drivers to invoke the shared sanity
check helper during probe.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     | 10 ++++++--
 drivers/crypto/atmel-i2c.c     | 43 ++++++++++++----------------------
 drivers/crypto/atmel-i2c.h     | 14 +++--------
 drivers/crypto/atmel-sha204a.c |  6 +++++
 4 files changed, 32 insertions(+), 41 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index f08fdf284b60..f6d1a9694d63 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -81,7 +81,7 @@ static void atmel_ecdh_done(struct atmel_i2c_work_data *work_data, void *areq,
 
 	/* copy the shared secret */
 	copied = sg_copy_from_buffer(req->dst, sg_nents_for_len(req->dst, n_sz),
-				     &cmd->data[RSP_DATA_IDX], n_sz);
+				     &cmd->data[ATMEL_I2C_RSP_DATA_IDX], n_sz);
 	if (copied != n_sz)
 		status = -EINVAL;
 
@@ -144,7 +144,7 @@ static int atmel_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
 		goto free_public_key;
 
 	/* save the public key */
-	memcpy(public_key, &cmd->data[RSP_DATA_IDX], ATMEL_ECC_PUBKEY_SIZE);
+	memcpy(public_key, &cmd->data[ATMEL_I2C_RSP_DATA_IDX], ATMEL_ECC_PUBKEY_SIZE);
 	ctx->public_key = public_key;
 
 	kfree(cmd);
@@ -323,6 +323,12 @@ static int atmel_ecc_probe(struct i2c_client *client)
 	i2c_priv->data = data;
 	i2c_priv->caps = BIT(ATMEL_CAP_ECDH);
 
+	ret = atmel_i2c_device_sanity_check(client);
+	if (ret) {
+		dev_err(&client->dev, "failed to read EEPROM, is hardware attached?\n");
+		goto done;
+	}
+
 	/* add to client list */
 	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 	list_add_tail(&i2c_priv->i2c_client_list_node,
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 26863573a10f..50b6bce478d2 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -23,6 +23,11 @@
 
 #define ATMEL_I2C_COMMAND			0x03 /* packet function */
 
+/* Definitions for the device lock state */
+#define ATMEL_I2C_DEVICE_LOCK_ADDR		0x15
+#define ATMEL_I2C_LOCK_VALUE_IDX		(ATMEL_I2C_RSP_DATA_IDX + 2)
+#define ATMEL_I2C_LOCK_CONFIG_IDX		(ATMEL_I2C_RSP_DATA_IDX + 3)
+
 /* Command opcode */
 #define ATMEL_I2C_OPCODE_ECDH			0x43
 #define ATMEL_I2C_OPCODE_GENKEY			0x40
@@ -129,26 +134,6 @@ static int atmel_i2c_init_read_eeprom_cmd(struct atmel_i2c_cmd *cmd, u16 addr,
 	return 0;
 }
 
-void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
-				    const struct atmel_i2c_max_exec_timings *timings)
-{
-	cmd->word_addr = ATMEL_I2C_COMMAND;
-	cmd->opcode = ATMEL_I2C_OPCODE_READ;
-	/*
-	 * Read the word from Configuration zone that contains the lock bytes
-	 * (UserExtra, Selector, LockValue, LockConfig).
-	 */
-	cmd->param1 = CONFIGURATION_ZONE;
-	cmd->param2 = cpu_to_le16(DEVICE_LOCK_ADDR);
-	cmd->count = ATMEL_I2C_READ_COUNT;
-
-	atmel_i2c_checksum(cmd);
-
-	cmd->msecs = timings->max_exec_time_read;
-	cmd->rxsize = ATMEL_I2C_READ_RSP_SIZE;
-}
-EXPORT_SYMBOL(atmel_i2c_init_read_config_cmd);
-
 void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
 			       const struct atmel_i2c_max_exec_timings *timings)
 {
@@ -247,7 +232,7 @@ static int atmel_i2c_rng_read_nonblocking(struct hwrng *rng, void *buf,
 	if (rng->priv) {
 		work_data = (struct atmel_i2c_work_data *)rng->priv;
 		max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
-		memcpy(buf, &work_data->cmd.data[RSP_DATA_IDX], max);
+		memcpy(buf, &work_data->cmd.data[ATMEL_I2C_RSP_DATA_IDX], max);
 		rng->priv = 0;
 	} else {
 		work_data = kmalloc_obj(*work_data, GFP_ATOMIC);
@@ -287,7 +272,7 @@ static int atmel_i2c_rng_read(struct hwrng *rng, void *buf, size_t max,
 		return ret;
 
 	max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
-	memcpy(buf, &cmd.data[RSP_DATA_IDX], max);
+	memcpy(buf, &cmd.data[ATMEL_I2C_RSP_DATA_IDX], max);
 
 	return max;
 }
@@ -338,7 +323,7 @@ static int atmel_i2c_eeprom_read(struct i2c_client *client, u16 addr,
 		goto err;
 	}
 
-	memcpy(buf, cmd->data + RSP_DATA_IDX, 4);
+	memcpy(buf, cmd->data + ATMEL_I2C_RSP_DATA_IDX, 4);
 
 err:
 	kfree(cmd);
@@ -542,7 +527,7 @@ static inline size_t atmel_i2c_wake_token_sz(u32 bus_clk_rate)
 	return DIV_ROUND_UP(no_of_bits, 8);
 }
 
-static int device_sanity_check(struct i2c_client *client)
+int atmel_i2c_device_sanity_check(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
 	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
@@ -553,7 +538,8 @@ static int device_sanity_check(struct i2c_client *client)
 	if (!cmd)
 		return -ENOMEM;
 
-	atmel_i2c_init_read_config_cmd(cmd, &data->timings);
+	atmel_i2c_init_read_eeprom_cmd(cmd, ATMEL_I2C_DEVICE_LOCK_ADDR,
+				       ATMEL_EEPROM_CONFIG_ZONE, data);
 
 	ret = atmel_i2c_send_receive(client, cmd);
 	if (ret)
@@ -565,8 +551,8 @@ static int device_sanity_check(struct i2c_client *client)
 	 * Failure to lock these zones may permit modification of any secret
 	 * keys and may lead to other security problems.
 	 */
-	if (cmd->data[LOCK_CONFIG_IDX] || cmd->data[LOCK_VALUE_IDX]) {
-		dev_err(&client->dev, "Configuration or Data and OTP zones are unlocked!\n");
+	if (cmd->data[ATMEL_I2C_LOCK_CONFIG_IDX] || cmd->data[ATMEL_I2C_LOCK_VALUE_IDX]) {
+		dev_err(&client->dev, "Config, Data and OTP zones are unlocked!\n");
 		ret = -ENOTSUPP;
 	}
 
@@ -575,6 +561,7 @@ static int device_sanity_check(struct i2c_client *client)
 	kfree(cmd);
 	return ret;
 }
+EXPORT_SYMBOL(atmel_i2c_device_sanity_check);
 
 void atmel_i2c_unregister_client(struct atmel_i2c_client_priv *i2c_priv)
 {
@@ -633,7 +620,7 @@ int atmel_i2c_probe(struct i2c_client *client)
 
 	i2c_set_clientdata(client, i2c_priv);
 
-	return device_sanity_check(client);
+	return 0;
 }
 EXPORT_SYMBOL(atmel_i2c_probe);
 
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index e30e0c417de2..2f76e107340e 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -82,18 +82,10 @@ struct atmel_i2c_of_match_data {
 #define STATUS_NOERR			0x00
 #define STATUS_WAKE_SUCCESSFUL		0x11
 
-/* Definitions for eeprom organization */
-#define CONFIGURATION_ZONE		0
-
 /* Definitions for Indexes common to all commands */
-#define RSP_DATA_IDX			1 /* buffer index of data in response */
+#define ATMEL_I2C_RSP_DATA_IDX		1 /* buffer index of data in response */
 #define DATA_SLOT_2			2 /* used for ECDH private key */
 
-/* Definitions for the device lock state */
-#define DEVICE_LOCK_ADDR		0x15
-#define LOCK_VALUE_IDX			(RSP_DATA_IDX + 2)
-#define LOCK_CONFIG_IDX			(RSP_DATA_IDX + 3)
-
 /*
  * Wake High delay to data communication (microseconds). SDA should be stable
  * high for this entire duration.
@@ -195,8 +187,6 @@ void atmel_i2c_flush_queue(void);
 
 int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd);
 
-void atmel_i2c_init_read_config_cmd(struct atmel_i2c_cmd *cmd,
-				    const struct atmel_i2c_max_exec_timings *timings);
 void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
 			       const struct atmel_i2c_max_exec_timings *timings);
 void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
@@ -207,6 +197,8 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 int atmel_i2c_register_rng(struct atmel_i2c_client_priv *i2c_priv,
 			   struct device *dev);
 
+int atmel_i2c_device_sanity_check(struct i2c_client *client);
+
 ssize_t atmel_i2c_eeprom_display(struct device *dev,
 				 struct device_attribute *attr,
 				 char *buf,
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 341554b7b7a2..88726f6ef87c 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -64,6 +64,12 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 	i2c_priv->data = data;
 	i2c_priv->caps = 0;
 
+	ret = atmel_i2c_device_sanity_check(client);
+	if (ret) {
+		dev_err(&client->dev, "failed to read EEPROM, is hardware attached?\n");
+		goto done;
+	}
+
 	/* add to client list */
 	spin_lock(&atmel_i2c_mgmt.i2c_list_lock);
 	list_add_tail(&i2c_priv->i2c_client_list_node,
-- 
2.53.0

[PATCH 09/12] crypto: atmel - check client data in remove callbacks

[Lothar Rubusch]

Check the i2c client private data pointer in the remove callbacks of
the Atmel ECC and SHA204A drivers before accessing driver state.
Move sysfs group removal ahead of the NULL check so cleanup can still
proceed even if client data is unavailable. Also downgrade the
busy-device warning in the ECC remove path from dev_emerg() to
dev_warn().

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     | 20 ++++++--------------
 drivers/crypto/atmel-sha204a.c |  7 +++++--
 2 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index f6d1a9694d63..9ad6d42b6eef 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -380,19 +380,13 @@ static void atmel_ecc_remove(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
 
-	/* Return EBUSY if i2c client already allocated. */
-	if (atomic_read(&i2c_priv->tfm_count)) {
-		/*
-		 * After we return here, the memory backing the device is freed.
-		 * That happens no matter what the return value of this function
-		 * is because in the Linux device model there is no error
-		 * handling for unbinding a driver.
-		 * If there is still some action pending, it probably involves
-		 * accessing the freed memory.
-		 */
-		dev_emerg(&client->dev, "Device is busy, expect memory corruption.\n");
+	sysfs_remove_group(&client->dev.kobj, &atmel_ecc508a_groups);
+
+	if (!i2c_priv)
 		return;
-	}
+
+	if (atomic_read(&i2c_priv->tfm_count))
+		dev_warn(&client->dev, "Device is busy, remove it anyhow\n");
 
 	atmel_i2c_unregister_client(i2c_priv);
 	atmel_i2c_flush_queue();
@@ -403,8 +397,6 @@ static void atmel_ecc_remove(struct i2c_client *client)
 		kfree((void *)i2c_priv->hwrng.priv);
 		i2c_priv->hwrng.priv = 0;
 	}
-
-	sysfs_remove_group(&client->dev.kobj, &atmel_ecc508a_groups);
 }
 
 static const struct atmel_i2c_of_match_data atecc508a_match_data = {
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 88726f6ef87c..6a41024ae40d 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -111,6 +111,11 @@ static void atmel_sha204a_remove(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
 
+	sysfs_remove_group(&client->dev.kobj, &atmel_sha204a_groups);
+
+	if (!i2c_priv)
+		return;
+
 	devm_hwrng_unregister(&client->dev, &i2c_priv->hwrng);
 	atmel_i2c_flush_queue();
 
@@ -118,8 +123,6 @@ static void atmel_sha204a_remove(struct i2c_client *client)
 		kfree((void *)i2c_priv->hwrng.priv);
 		i2c_priv->hwrng.priv = 0;
 	}
-
-	sysfs_remove_group(&client->dev.kobj, &atmel_sha204a_groups);
 }
 
 static const struct atmel_i2c_of_match_data atsha204_match_data = {
-- 
2.53.0

[PATCH 10/12] crypto: atmel - update workqueue flags and add flush on exit

[Lothar Rubusch]

Update workqueue initialization to use WQ_MEM_RECLAIM instead of
WQ_PERCPU. WQ_MEM_RECLAIM already provides per-CPU execution
semantics via a bound workqueue while also ensuring forward progress
via a rescue thread.

Add a flush_workqueue() call during module exit to ensure all queued
work is completed before destroying the workqueue.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-i2c.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 50b6bce478d2..0ec2d768a763 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -626,12 +626,13 @@ EXPORT_SYMBOL(atmel_i2c_probe);
 
 static int __init atmel_i2c_init(void)
 {
-	atmel_wq = alloc_workqueue("atmel_wq", WQ_PERCPU, 0);
+	atmel_wq = alloc_workqueue("atmel_wq", WQ_MEM_RECLAIM, 0);
 	return atmel_wq ? 0 : -ENOMEM;
 }
 
 static void __exit atmel_i2c_exit(void)
 {
+	flush_workqueue(atmel_wq);
 	destroy_workqueue(atmel_wq);
 }
 
-- 
2.53.0

[PATCH 11/12] crypto: atmel - refactor and localize driver constants

[Lothar Rubusch]

After refactoring the client drivers to use the shared atmel-i2c core,
many constants and definitions no longer need global visibility.

Move command definitions, timing constants, status codes and related
helpers from the public header into the local compile unit of the core
driver where possible.

As part of this cleanup, rename macros and constants to use consistent
ATMEL_I2C_* naming and align them with common kernel driver conventions.
Also replace remaining hardcoded values with named constants throughout
the driver.

This is a preparatory cleanup and does not change functionality.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c |   4 +-
 drivers/crypto/atmel-i2c.c | 115 +++++++++++++++++++++++++------------
 drivers/crypto/atmel-i2c.h |  76 +++++++++---------------
 3 files changed, 108 insertions(+), 87 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index 9ad6d42b6eef..ed8c0ce5562b 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -137,7 +137,7 @@ static int atmel_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
 
 	ctx->do_fallback = false;
 
-	atmel_i2c_init_genkey_cmd(cmd, DATA_SLOT_2, &data->timings);
+	atmel_i2c_init_genkey_cmd(cmd, ATMEL_I2C_ECDH_SLOT_DEFAULT, &data->timings);
 
 	ret = atmel_i2c_send_receive(ctx->client, cmd);
 	if (ret)
@@ -296,7 +296,7 @@ static struct kpp_alg atmel_ecdh_nist_p256 = {
 		.cra_flags = CRYPTO_ALG_NEED_FALLBACK,
 		.cra_name = "ecdh-nist-p256",
 		.cra_driver_name = "atmel-ecdh",
-		.cra_priority = ATMEL_ECC_PRIORITY,
+		.cra_priority = ATMEL_I2C_PRIORITY,
 		.cra_module = THIS_MODULE,
 		.cra_ctxsize = sizeof(struct atmel_ecdh_ctx),
 	},
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 0ec2d768a763..53aba2f4bedb 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -21,19 +21,62 @@
 #include <linux/workqueue.h>
 #include "atmel-i2c.h"
 
-#define ATMEL_I2C_COMMAND			0x03 /* packet function */
+#define ATMEL_I2C_COMMAND		0x03 /* packet function */
+#define ATMEL_I2C_SLEEP_TOKEN		0x01
 
 /* Definitions for the device lock state */
-#define ATMEL_I2C_DEVICE_LOCK_ADDR		0x15
-#define ATMEL_I2C_LOCK_VALUE_IDX		(ATMEL_I2C_RSP_DATA_IDX + 2)
-#define ATMEL_I2C_LOCK_CONFIG_IDX		(ATMEL_I2C_RSP_DATA_IDX + 3)
+#define ATMEL_I2C_DEVICE_LOCK_ADDR	0x15
+#define ATMEL_I2C_LOCK_VALUE_IDX	(ATMEL_I2C_RSP_DATA_IDX + 2)
+#define ATMEL_I2C_LOCK_CONFIG_IDX	(ATMEL_I2C_RSP_DATA_IDX + 3)
+
+/* Definitions for the READ Command */
+#define ATMEL_I2C_READ_COUNT		ATMEL_I2C_COUNT_OVERHEAD_SIZE
+#define ATMEL_I2C_READ_RSP_SIZE		(4 + ATMEL_I2C_RSP_OVERHEAD_SIZE)
+
+/* Definitions for the RANDOM Command */
+#define ATMEL_I2C_RANDOM_COUNT		ATMEL_I2C_COUNT_OVERHEAD_SIZE
+#define ATMEL_I2C_RNG_BLOCK_SIZE	32
+#define ATMEL_I2C_RANDOM_RSP_SIZE	(ATMEL_I2C_RNG_BLOCK_SIZE + \
+					ATMEL_I2C_RSP_OVERHEAD_SIZE)
+#define ATMEL_I2C_RANDOM_COUNT		ATMEL_I2C_COUNT_OVERHEAD_SIZE
+
+/* Definitions for the GenKey Command */
+#define ATMEL_I2C_GENKEY_COUNT		ATMEL_I2C_COUNT_OVERHEAD_SIZE
+#define ATMEL_I2C_GENKEY_MODE_PRIVATE	0x04
+
+/* Definitions for the ECDH Command */
+#define ATMEL_I2C_ECDH_COUNT		71
+#define ATMEL_I2C_ECDH_RSP_SIZE		(32 + ATMEL_I2C_RSP_OVERHEAD_SIZE)
+#define ATMEL_I2C_ECDH_PREFIX_MODE	0x00
 
 /* Command opcode */
-#define ATMEL_I2C_OPCODE_ECDH			0x43
-#define ATMEL_I2C_OPCODE_GENKEY			0x40
-#define ATMEL_I2C_OPCODE_READ			0x02
-#define ATMEL_I2C_OPCODE_RANDOM			0x1b
-#define ATMEL_I2C_OPCODE_WRITE			0x12
+#define ATMEL_I2C_OPCODE_ECDH		0x43
+#define ATMEL_I2C_OPCODE_GENKEY		0x40
+#define ATMEL_I2C_OPCODE_READ		0x02
+#define ATMEL_I2C_OPCODE_RANDOM		0x1b
+#define ATMEL_I2C_OPCODE_WRITE		0x12
+
+/*
+ * Wake High delay to data communication (microseconds). SDA should be stable
+ * high for this entire duration.
+ */
+#define ATMEL_I2C_TWHI_MIN		1500
+#define ATMEL_I2C_TWHI_MAX		1550
+
+/* Wake Low duration */
+#define ATMEL_I2C_TWLO_USEC		60
+
+/* Status/Error codes */
+enum atmel_i2c_error_codes {
+	ATMEL_STATUS_OK_NOERR = 0x00,            /* success */
+	ATMEL_STATUS_CHECKMAC_OR_VERIFY_MISCOMPARE = 0x01,
+	ATMEL_STATUS_PARSE_ERROR = 0x03,
+	ATMEL_STATUS_ECC_FAULT = 0x05,
+	ATMEL_STATUS_EXECUTION_FAULT = 0x0F,
+	ATMEL_STATUS_OK_WAKE_SUCCESSFULL = 0x11, /* success */
+	ATMEL_STATUS_WATCHDOG_EXPIRE = 0xEE,
+	ATMEL_STATUS_CRC_ERROR = 0xFF,
+};
 
 struct atmel_i2c_client_mgmt atmel_i2c_mgmt = {
 	.i2c_list_lock = __SPIN_LOCK_UNLOCKED(atmel_i2c_mgmt.i2c_list_lock),
@@ -45,12 +88,12 @@ static const struct {
 	u8 value;
 	const char *error_text;
 } error_list[] = {
-	{ 0x01, "CheckMac or Verify miscompare" },
-	{ 0x03, "Parse Error" },
-	{ 0x05, "ECC Fault" },
-	{ 0x0F, "Execution Error" },
-	{ 0xEE, "Watchdog about to expire" },
-	{ 0xFF, "CRC or other communication error" },
+	{ ATMEL_STATUS_CHECKMAC_OR_VERIFY_MISCOMPARE, "CheckMac or Verify miscompare" },
+	{ ATMEL_STATUS_PARSE_ERROR, "Parse Error" },
+	{ ATMEL_STATUS_ECC_FAULT, "ECC Fault" },
+	{ ATMEL_STATUS_EXECUTION_FAULT, "Execution Error" },
+	{ ATMEL_STATUS_WATCHDOG_EXPIRE, "Watchdog about to expire" },
+	{ ATMEL_STATUS_CRC_ERROR, "CRC or other communication error" },
 };
 
 /**
@@ -65,7 +108,7 @@ static const struct {
 static void atmel_i2c_checksum(struct atmel_i2c_cmd *cmd)
 {
 	u8 *data = &cmd->count;
-	size_t len = cmd->count - CRC_SIZE;
+	size_t len = cmd->count - ATMEL_I2C_CRC_SIZE;
 	__le16 *__crc16 = (__le16 *)(data + len);
 
 	*__crc16 = cpu_to_le16(bitrev16(crc16(0, data, len)));
@@ -141,12 +184,12 @@ void atmel_i2c_init_random_cmd(struct atmel_i2c_cmd *cmd,
 	cmd->opcode = ATMEL_I2C_OPCODE_RANDOM;
 	cmd->param1 = 0;
 	cmd->param2 = 0;
-	cmd->count = RANDOM_COUNT;
+	cmd->count = ATMEL_I2C_RANDOM_COUNT;
 
 	atmel_i2c_checksum(cmd);
 
 	cmd->msecs = timings->max_exec_time_random;
-	cmd->rxsize = RANDOM_RSP_SIZE;
+	cmd->rxsize = ATMEL_I2C_RANDOM_RSP_SIZE;
 }
 EXPORT_SYMBOL(atmel_i2c_init_random_cmd);
 
@@ -154,16 +197,16 @@ void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
 			       const struct atmel_i2c_max_exec_timings *timings)
 {
 	cmd->word_addr = ATMEL_I2C_COMMAND;
-	cmd->count = GENKEY_COUNT;
+	cmd->count = ATMEL_I2C_GENKEY_COUNT;
 	cmd->opcode = ATMEL_I2C_OPCODE_GENKEY;
-	cmd->param1 = GENKEY_MODE_PRIVATE;
+	cmd->param1 = ATMEL_I2C_GENKEY_MODE_PRIVATE;
 	/* a random private key will be generated and stored in slot keyID */
 	cmd->param2 = cpu_to_le16(keyid);
 
 	atmel_i2c_checksum(cmd);
 
 	cmd->msecs = timings->max_exec_time_genkey;
-	cmd->rxsize = GENKEY_RSP_SIZE;
+	cmd->rxsize = ATMEL_I2C_GENKEY_RSP_SIZE;
 }
 EXPORT_SYMBOL(atmel_i2c_init_genkey_cmd);
 
@@ -174,11 +217,11 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 	size_t copied;
 
 	cmd->word_addr = ATMEL_I2C_COMMAND;
-	cmd->count = ECDH_COUNT;
+	cmd->count = ATMEL_I2C_ECDH_COUNT;
 	cmd->opcode = ATMEL_I2C_OPCODE_ECDH;
-	cmd->param1 = ECDH_PREFIX_MODE;
+	cmd->param1 = ATMEL_I2C_ECDH_PREFIX_MODE;
 	/* private key slot */
-	cmd->param2 = cpu_to_le16(DATA_SLOT_2);
+	cmd->param2 = cpu_to_le16(ATMEL_I2C_ECDH_SLOT_DEFAULT);
 
 	/*
 	 * The device only supports NIST P256 ECC keys. The public key size will
@@ -195,7 +238,7 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 	atmel_i2c_checksum(cmd);
 
 	cmd->msecs = timings->max_exec_time_ecdh;
-	cmd->rxsize = ECDH_RSP_SIZE;
+	cmd->rxsize = ATMEL_I2C_ECDH_RSP_SIZE;
 
 	return 0;
 }
@@ -231,7 +274,7 @@ static int atmel_i2c_rng_read_nonblocking(struct hwrng *rng, void *buf,
 
 	if (rng->priv) {
 		work_data = (struct atmel_i2c_work_data *)rng->priv;
-		max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
+		max = min(ATMEL_I2C_RANDOM_RSP_SIZE - ATMEL_I2C_RSP_OVERHEAD_SIZE, max);
 		memcpy(buf, &work_data->cmd.data[ATMEL_I2C_RSP_DATA_IDX], max);
 		rng->priv = 0;
 	} else {
@@ -271,7 +314,7 @@ static int atmel_i2c_rng_read(struct hwrng *rng, void *buf, size_t max,
 	if (ret)
 		return ret;
 
-	max = min(RANDOM_RSP_SIZE - CMD_OVERHEAD_SIZE, max);
+	max = min(ATMEL_I2C_RANDOM_RSP_SIZE - ATMEL_I2C_RSP_OVERHEAD_SIZE, max);
 	memcpy(buf, &cmd.data[ATMEL_I2C_RSP_DATA_IDX], max);
 
 	return max;
@@ -323,7 +366,7 @@ static int atmel_i2c_eeprom_read(struct i2c_client *client, u16 addr,
 		goto err;
 	}
 
-	memcpy(buf, cmd->data + ATMEL_I2C_RSP_DATA_IDX, 4);
+	memcpy(buf, cmd->data + ATMEL_I2C_RSP_DATA_IDX, ATMEL_I2C_STATUS_RSP_SIZE);
 
 err:
 	kfree(cmd);
@@ -381,10 +424,10 @@ static int atmel_i2c_status(struct device *dev, u8 *status)
 	int i;
 	u8 err_id = status[1];
 
-	if (*status != STATUS_SIZE)
+	if (*status != ATMEL_I2C_STATUS_RSP_SIZE)
 		return 0;
 
-	if (err_id == STATUS_WAKE_SUCCESSFUL || err_id == STATUS_NOERR)
+	if (err_id == ATMEL_STATUS_OK_WAKE_SUCCESSFULL || err_id == ATMEL_STATUS_OK_NOERR)
 		return 0;
 
 	for (i = 0; i < err_list_len; i++)
@@ -403,7 +446,7 @@ static int atmel_i2c_status(struct device *dev, u8 *status)
 static int atmel_i2c_wakeup(struct i2c_client *client)
 {
 	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
-	u8 status[STATUS_RSP_SIZE];
+	u8 status[ATMEL_I2C_STATUS_RSP_SIZE];
 	int ret;
 
 	/*
@@ -418,9 +461,9 @@ static int atmel_i2c_wakeup(struct i2c_client *client)
 	 * Wait to wake the device. Typical execution times for ecdh and genkey
 	 * are around tens of milliseconds. Delta is chosen to 50 microseconds.
 	 */
-	usleep_range(TWHI_MIN, TWHI_MAX);
+	usleep_range(ATMEL_I2C_TWHI_MIN, ATMEL_I2C_TWHI_MAX);
 
-	ret = i2c_master_recv(client, status, STATUS_SIZE);
+	ret = i2c_master_recv(client, status, ATMEL_I2C_STATUS_RSP_SIZE);
 	if (ret < 0)
 		return ret;
 
@@ -429,7 +472,7 @@ static int atmel_i2c_wakeup(struct i2c_client *client)
 
 static int atmel_i2c_sleep(struct i2c_client *client)
 {
-	u8 sleep = SLEEP_TOKEN;
+	u8 sleep = ATMEL_I2C_SLEEP_TOKEN;
 
 	return i2c_master_send(client, &sleep, 1);
 }
@@ -461,7 +504,7 @@ int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
 		goto err;
 
 	/* send the command */
-	ret = i2c_master_send(client, (u8 *)cmd, cmd->count + WORD_ADDR_SIZE);
+	ret = i2c_master_send(client, (u8 *)cmd, cmd->count + ATMEL_I2C_ADDR_SIZE);
 	if (ret < 0)
 		goto err;
 
@@ -521,7 +564,7 @@ EXPORT_SYMBOL(atmel_i2c_flush_queue);
 
 static inline size_t atmel_i2c_wake_token_sz(u32 bus_clk_rate)
 {
-	u32 no_of_bits = DIV_ROUND_UP(TWLO_USEC * bus_clk_rate, USEC_PER_SEC);
+	u32 no_of_bits = DIV_ROUND_UP(ATMEL_I2C_TWLO_USEC * bus_clk_rate, USEC_PER_SEC);
 
 	/* return the size of the wake_token in bytes */
 	return DIV_ROUND_UP(no_of_bits, 8);
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 2f76e107340e..20afe2da4f8d 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -10,28 +10,39 @@
 #include <linux/hw_random.h>
 #include <linux/types.h>
 
-#define ATMEL_ECC_PRIORITY		300
+#define ATMEL_I2C_PRIORITY		300
 
-#define SLEEP_TOKEN			0x01
-#define WAKE_TOKEN_MAX_SIZE		8
+#define ATMEL_I2C_WAKE_TOKEN_MAX_SIZE	8
 
 /* Definitions of Data and Command sizes */
-#define WORD_ADDR_SIZE			1
-#define COUNT_SIZE			1
-#define CRC_SIZE			2
-#define CMD_OVERHEAD_SIZE		(COUNT_SIZE + CRC_SIZE)
+#define ATMEL_I2C_ADDR_SIZE		1
+#define ATMEL_I2C_OPCODE_SIZE		1
+#define ATMEL_I2C_COUNT_SIZE		1
+#define ATMEL_I2C_PARAM1_SIZE		1
+#define ATMEL_I2C_PARAM2_SIZE		2
+#define ATMEL_I2C_CRC_SIZE		2
+
+#define ATMEL_I2C_RSP_OVERHEAD_SIZE	(ATMEL_I2C_COUNT_SIZE + \
+					ATMEL_I2C_CRC_SIZE)
+#define ATMEL_I2C_COUNT_OVERHEAD_SIZE	(ATMEL_I2C_OPCODE_SIZE + \
+					ATMEL_I2C_COUNT_SIZE + \
+					ATMEL_I2C_PARAM1_SIZE + \
+					ATMEL_I2C_PARAM2_SIZE + \
+					ATMEL_I2C_CRC_SIZE)
+
+/* Definitions for the status Command */
+#define ATMEL_I2C_STATUS_RSP_SIZE	4
 
 /* size in bytes of the n prime */
 #define ATMEL_ECC_NIST_P256_N_SIZE	32
 #define ATMEL_ECC_PUBKEY_SIZE		(2 * ATMEL_ECC_NIST_P256_N_SIZE)
+#define ATMEL_I2C_GENKEY_RSP_SIZE	(ATMEL_ECC_PUBKEY_SIZE + \
+					 ATMEL_I2C_RSP_OVERHEAD_SIZE)
+#define ATMEL_I2C_MAX_RSP_SIZE		ATMEL_I2C_GENKEY_RSP_SIZE
 
-#define STATUS_RSP_SIZE			4
-#define ECDH_RSP_SIZE			(32 + CMD_OVERHEAD_SIZE)
-#define GENKEY_RSP_SIZE			(ATMEL_ECC_PUBKEY_SIZE + \
-					 CMD_OVERHEAD_SIZE)
-#define ATMEL_I2C_READ_RSP_SIZE		(4 + CMD_OVERHEAD_SIZE)
-#define RANDOM_RSP_SIZE			(32 + CMD_OVERHEAD_SIZE)
-#define MAX_RSP_SIZE			GENKEY_RSP_SIZE
+/* Definitions for Indexes common to all commands */
+#define ATMEL_I2C_RSP_DATA_IDX		1 /* buffer index of data in response */
+#define ATMEL_I2C_ECDH_SLOT_DEFAULT	2
 
 /**
  * atmel_i2c_cmd - structure used for communicating with the device.
@@ -51,7 +62,7 @@ struct atmel_i2c_cmd {
 	u8 opcode;
 	u8 param1;
 	__le16 param2;
-	u8 data[MAX_RSP_SIZE];
+	u8 data[ATMEL_I2C_MAX_RSP_SIZE];
 	u8 msecs;
 	u16 rxsize;
 } __packed;
@@ -77,39 +88,6 @@ struct atmel_i2c_of_match_data {
 	size_t eeprom_zone_size[3]; /* all atmel devices have three zones */
 };
 
-/* Status/Error codes */
-#define STATUS_SIZE			0x04
-#define STATUS_NOERR			0x00
-#define STATUS_WAKE_SUCCESSFUL		0x11
-
-/* Definitions for Indexes common to all commands */
-#define ATMEL_I2C_RSP_DATA_IDX		1 /* buffer index of data in response */
-#define DATA_SLOT_2			2 /* used for ECDH private key */
-
-/*
- * Wake High delay to data communication (microseconds). SDA should be stable
- * high for this entire duration.
- */
-#define TWHI_MIN			1500
-#define TWHI_MAX			1550
-
-/* Wake Low duration */
-#define TWLO_USEC			60
-
-/* Definitions for the READ Command */
-#define ATMEL_I2C_READ_COUNT		7
-
-/* Definitions for the RANDOM Command */
-#define RANDOM_COUNT			7
-
-/* Definitions for the GenKey Command */
-#define GENKEY_COUNT			7
-#define GENKEY_MODE_PRIVATE		0x04
-
-/* Definitions for the ECDH Command */
-#define ECDH_COUNT			71
-#define ECDH_PREFIX_MODE		0x00
-
 /* Used for binding tfm objects to i2c clients. */
 enum atmel_i2c_capability {
 	ATMEL_CAP_ECDH = 0,
@@ -144,7 +122,7 @@ struct atmel_i2c_client_priv {
 	struct i2c_client *client;
 	struct list_head i2c_client_list_node;
 	struct mutex lock;
-	u8 wake_token[WAKE_TOKEN_MAX_SIZE];
+	u8 wake_token[ATMEL_I2C_WAKE_TOKEN_MAX_SIZE];
 	size_t wake_token_sz;
 	atomic_t tfm_count ____cacheline_aligned;
 	struct hwrng hwrng;
-- 
2.53.0

[PATCH 12/12] crypto: atmel - add SHA256 ahash support

[Lothar Rubusch]

Add SHA256 ahash support for ATSHA204A and ECC based devices using
the hardware SHA engine provided by the Atmel secure element devices.

Implement common SHA256 request handling in the atmel-i2c core driver,
including init, update, final, finup, digest, export and import
operations. Scatterlist input is processed using the crypto hash
walker.

ATSHA204A devices require software-side SHA256 padding according to
FIPS 180-4 before submitting the final data blocks to the device.
Newer ECC devices instead support a dedicated SHA final command which
performs padding internally in hardware. For these devices, the final
block length is passed through the command parameter field.

The SHA engine requires a strict multi-command transaction sequence:
SHA INIT, followed by one or more SHA COMPUTE operations and, on ECC
devices, a terminating SHA FINAL operation. The device SHA context is
lost if the device enters sleep mode or if unrelated commands are
interleaved during the sequence.

To support these hardware requirements, split the existing
send/receive helper into a low-level transfer helper and a higher
level wrapper handling wakeup, sleep and locking. SHA operations keep
the device awake and hold the i2c client lock across the complete hash
transaction until the final digest has been retrieved.

Register the SHA256 ahash algorithm in both atmel-sha204a and
atmel-ecc drivers and add capability based client allocation for SHA
operations.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/crypto/atmel-ecc.c     |  50 +++++-
 drivers/crypto/atmel-i2c.c     | 273 +++++++++++++++++++++++++++++++--
 drivers/crypto/atmel-i2c.h     |  40 +++++
 drivers/crypto/atmel-sha204a.c |  55 ++++++-
 4 files changed, 407 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index ed8c0ce5562b..aacf9e8add7a 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -19,10 +19,50 @@
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <crypto/internal/kpp.h>
+#include <crypto/internal/hash.h>
 #include <crypto/ecdh.h>
 #include <crypto/kpp.h>
+#include <crypto/sha2.h>
 #include "atmel-i2c.h"
 
+static int atmel_ecc_sha_init_tfm(struct crypto_tfm *tfm)
+{
+	struct atmel_i2c_sha_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->client = atmel_i2c_client_alloc(ATMEL_CAP_SHA);
+	if (IS_ERR(ctx->client)) {
+		pr_err("tfm - i2c_client binding failed\n");
+		return PTR_ERR(ctx->client);
+	}
+
+	return 0;
+}
+
+static struct ahash_alg atmel_ecc_sha = {
+	.init = atmel_i2c_sha_init,
+	.update	= atmel_i2c_sha_update,
+	.final = atmel_i2c_sha_final,
+	.finup = atmel_i2c_sha_finup,
+	.digest	= atmel_i2c_sha_digest,
+	.export = atmel_i2c_sha_export,
+	.import = atmel_i2c_sha_import,
+	.halg = {
+		.digestsize = SHA256_DIGEST_SIZE,
+		.statesize = sizeof(struct atmel_i2c_sha_reqctx),
+		.base = {
+			.cra_name		= "sha256",
+			.cra_driver_name	= "atmel-sha256",
+			.cra_init		= atmel_ecc_sha_init_tfm,
+			.cra_priority		= ATMEL_I2C_PRIORITY,
+			.cra_flags		= CRYPTO_ALG_TYPE_AHASH,
+			.cra_blocksize		= SHA256_BLOCK_SIZE,
+			.cra_ctxsize		= sizeof(struct atmel_i2c_sha_ctx),
+			.cra_reqsize		= sizeof(struct atmel_i2c_sha_reqctx),
+			.cra_module		= THIS_MODULE,
+		}
+	}
+};
+
 static ssize_t config_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_CONFIG_ZONE);
@@ -321,7 +361,7 @@ static int atmel_ecc_probe(struct i2c_client *client)
 
 	i2c_priv = i2c_get_clientdata(client);
 	i2c_priv->data = data;
-	i2c_priv->caps = BIT(ATMEL_CAP_ECDH);
+	i2c_priv->caps = BIT(ATMEL_CAP_ECDH) | BIT(ATMEL_CAP_SHA);
 
 	ret = atmel_i2c_device_sanity_check(client);
 	if (ret) {
@@ -364,6 +404,12 @@ static int atmel_ecc_probe(struct i2c_client *client)
 		dev_info(&client->dev, "atmel ecc algorithms registered in /proc/crypto\n");
 	}
 
+	ret = crypto_register_ahash(&atmel_ecc_sha);
+	if (ret) {
+		dev_err(&client->dev, "SHA256 registration failed\n");
+		goto err_list_del;
+	}
+
 	goto done;
 
 err_list_del:
@@ -392,6 +438,7 @@ static void atmel_ecc_remove(struct i2c_client *client)
 	atmel_i2c_flush_queue();
 
 	crypto_unregister_kpp(&atmel_ecdh_nist_p256);
+	crypto_unregister_ahash(&atmel_ecc_sha);
 
 	if (i2c_priv->hwrng.priv) {
 		kfree((void *)i2c_priv->hwrng.priv);
@@ -405,6 +452,7 @@ static const struct atmel_i2c_of_match_data atecc508a_match_data = {
 		.max_exec_time_genkey = 115,
 		.max_exec_time_random = 23,
 		.max_exec_time_read = 1,
+		.max_exec_time_sha = 9,
 		.max_exec_time_write = 42,
 	},
 	.eeprom_zone_size = {
diff --git a/drivers/crypto/atmel-i2c.c b/drivers/crypto/atmel-i2c.c
index 53aba2f4bedb..cbdc8c0e5aca 100644
--- a/drivers/crypto/atmel-i2c.c
+++ b/drivers/crypto/atmel-i2c.c
@@ -19,6 +19,10 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
+#include <crypto/hash.h>
+#include <crypto/sha2.h>
+#include <crypto/internal/hash.h>
+
 #include "atmel-i2c.h"
 
 #define ATMEL_I2C_COMMAND		0x03 /* packet function */
@@ -49,12 +53,17 @@
 #define ATMEL_I2C_ECDH_RSP_SIZE		(32 + ATMEL_I2C_RSP_OVERHEAD_SIZE)
 #define ATMEL_I2C_ECDH_PREFIX_MODE	0x00
 
+/* Definitions for the SHA Command */
+#define ATMEL_I2C_SHA_RSP_SIZE		(ATMEL_I2C_RSP_OVERHEAD_SIZE + \
+					SHA256_DIGEST_SIZE)
+
 /* Command opcode */
 #define ATMEL_I2C_OPCODE_ECDH		0x43
 #define ATMEL_I2C_OPCODE_GENKEY		0x40
 #define ATMEL_I2C_OPCODE_READ		0x02
 #define ATMEL_I2C_OPCODE_RANDOM		0x1b
 #define ATMEL_I2C_OPCODE_WRITE		0x12
+#define ATMEL_I2C_OPCODE_SHA		0x47
 
 /*
  * Wake High delay to data communication (microseconds). SDA should be stable
@@ -244,6 +253,43 @@ int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 }
 EXPORT_SYMBOL(atmel_i2c_init_ecdh_cmd);
 
+int atmel_i2c_init_sha_cmd(struct atmel_i2c_cmd *cmd,
+			   u8 *challenge, size_t len,
+			   enum atmel_i2c_sha_engine_cmd sha_engine_cmd,
+			   const struct atmel_i2c_max_exec_timings *timings)
+{
+	cmd->word_addr = ATMEL_I2C_COMMAND;
+	cmd->opcode = ATMEL_I2C_OPCODE_SHA;
+	cmd->param1 = sha_engine_cmd;
+
+	cmd->param2 = cpu_to_le16(0);
+	/*
+	 * Starting with the bigger ECCs, the device learned how to do SHA256
+	 * padding (FIPS 180-4). Since SHA UPDATE always consumes 64B (SHA256
+	 * block size), the only length needed to communicate is the number of
+	 * used bytes in the final block. For the Atmel ECC series, this is
+	 * passed in the param2.
+	 */
+	if (sha_engine_cmd == atmel_sha_ecc_end)
+		cmd->param2 = cpu_to_le16(len);
+
+	cmd->count = ATMEL_I2C_COUNT_OVERHEAD_SIZE;
+	if (sha_engine_cmd == atmel_sha_init) {
+		memset(cmd->data, 0, sizeof(cmd->data));
+	} else {
+		memcpy(cmd->data, challenge, len);
+		cmd->count += len;
+	}
+
+	atmel_i2c_checksum(cmd);
+
+	cmd->msecs = timings->max_exec_time_sha;
+	cmd->rxsize = atmel_i2c_sha_rsp_size[sha_engine_cmd];
+
+	return 0;
+}
+EXPORT_SYMBOL(atmel_i2c_init_sha_cmd);
+
 static void atmel_i2c_rng_done(struct atmel_i2c_work_data *work_data,
 			       void *areq, int status)
 {
@@ -492,21 +538,15 @@ static int atmel_i2c_sleep(struct i2c_client *client)
  * counter other than to put the device into sleep or idle mode and then
  * wake it up again.
  */
-int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
+static int _atmel_i2c_send_receive(struct i2c_client *client,
+				   struct atmel_i2c_cmd *cmd)
 {
-	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
 	int ret;
 
-	mutex_lock(&i2c_priv->lock);
-
-	ret = atmel_i2c_wakeup(client);
-	if (ret)
-		goto err;
-
 	/* send the command */
 	ret = i2c_master_send(client, (u8 *)cmd, cmd->count + ATMEL_I2C_ADDR_SIZE);
 	if (ret < 0)
-		goto err;
+		return ret;
 
 	/* delay the appropriate amount of time for command to execute */
 	msleep(cmd->msecs);
@@ -514,6 +554,24 @@ int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
 	/* receive the response */
 	ret = i2c_master_recv(client, cmd->data, cmd->rxsize);
 	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
+{
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
+	int ret;
+
+	mutex_lock(&i2c_priv->lock);
+
+	ret = atmel_i2c_wakeup(client);
+	if (ret)
+		goto err;
+
+	ret = _atmel_i2c_send_receive(client, cmd);
+	if (ret)
 		goto err;
 
 	/* put the device into low-power mode */
@@ -529,6 +587,203 @@ int atmel_i2c_send_receive(struct i2c_client *client, struct atmel_i2c_cmd *cmd)
 }
 EXPORT_SYMBOL(atmel_i2c_send_receive);
 
+int atmel_i2c_sha_init(struct ahash_request *req)
+{
+	struct atmel_i2c_sha_reqctx *rctx = ahash_request_ctx(req);
+	struct atmel_i2c_sha_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(ctx->client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	struct atmel_i2c_cmd *cmd;
+	int ret;
+
+	rctx->bufcnt = 0;
+	rctx->total = 0;
+	rctx->ctx = i2c_get_clientdata(ctx->client);
+
+	cmd = kmalloc_obj(*cmd);
+	if (!cmd)
+		return -ENOMEM;
+
+	/* SHA init */
+	ret = atmel_i2c_init_sha_cmd(cmd, NULL, 0, atmel_sha_init, &data->timings);
+	if (ret)
+		goto err_free;
+
+	mutex_lock(&i2c_priv->lock);
+
+	ret = atmel_i2c_wakeup(ctx->client);
+	if (ret)
+		goto err;
+
+	ret = _atmel_i2c_send_receive(ctx->client, cmd);
+	if (ret)
+		goto err;
+
+	/* we keep the lock hold until error out or _sha_final() is called */
+	return 0;
+err:
+	mutex_unlock(&i2c_priv->lock);
+err_free:
+	kfree_sensitive(cmd);
+	return ret;
+}
+EXPORT_SYMBOL(atmel_i2c_sha_init);
+
+int atmel_i2c_sha_update(struct ahash_request *req)
+{
+	struct atmel_i2c_sha_reqctx *rctx = ahash_request_ctx(req);
+	struct atmel_i2c_sha_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(ctx->client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	struct atmel_i2c_cmd *cmd;
+	struct crypto_hash_walk walk;
+	int nbytes, take, copied = 0;
+	const u8 *pdata;
+	int ret;
+
+	rctx->total += req->nbytes;
+
+	cmd = kmalloc_obj(*cmd);
+	if (!cmd) {
+		ret = -ENOMEM;
+		goto err_nomem;
+	}
+
+	/*
+	 * Note, we are actively holding the i2c_priv->lock while the SHA engine
+	 * operates. This covers init, update and final steps.
+	 */
+	nbytes = crypto_hash_walk_first(req, &walk);
+	for (; nbytes > 0; nbytes = crypto_hash_walk_done(&walk, copied)) {
+		copied = nbytes;
+		pdata = walk.data;
+		while (copied > 0) {
+			take = min(copied, SHA256_BLOCK_SIZE - rctx->bufcnt);
+
+			memcpy(rctx->buffer + rctx->bufcnt, pdata, take);
+			pdata += take;
+			copied -= take;
+			rctx->bufcnt += take;
+			if (rctx->bufcnt == SHA256_BLOCK_SIZE) {
+				ret = atmel_i2c_init_sha_cmd(cmd, rctx->buffer,
+							     SHA256_BLOCK_SIZE,
+							     atmel_sha_compute,
+							     &data->timings);
+				if (ret)
+					goto err;
+
+				ret = _atmel_i2c_send_receive(ctx->client, cmd);
+				if (ret)
+					goto err;
+
+				rctx->bufcnt = 0;
+			}
+		}
+	}
+
+	kfree_sensitive(cmd);
+	return 0;
+err:
+	kfree_sensitive(cmd);
+err_nomem:
+	mutex_unlock(&i2c_priv->lock);
+	return ret;
+}
+EXPORT_SYMBOL(atmel_i2c_sha_update);
+
+int atmel_i2c_sha_final(struct ahash_request *req)
+{
+	struct atmel_i2c_sha_reqctx *rctx = ahash_request_ctx(req);
+	struct atmel_i2c_sha_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(ctx->client);
+	const struct atmel_i2c_of_match_data *data = i2c_priv->data;
+	struct atmel_i2c_cmd *cmd;
+	u8 final_blocks[2 * SHA256_BLOCK_SIZE];
+	u32 total_pad;
+	__be64 bits;
+	int i, ret = 0;
+
+	cmd = kmalloc_obj(*cmd);
+	if (!cmd) {
+		ret = -ENOMEM;
+		goto err_nomem;
+	}
+
+	if (data->needs_sha_padding) {
+		/*
+		 * Determine if padding fits in current block or needs another,
+		 * SHA256 needs 8 bytes for length at the end of a 64-byte block.
+		 */
+		memset(final_blocks, 0, sizeof(final_blocks));
+		memcpy(final_blocks, rctx->buffer, rctx->bufcnt);
+		final_blocks[rctx->bufcnt] = 0x80; /* pad bit */
+		total_pad = SHA256_BLOCK_SIZE * (rctx->bufcnt < 56 ? 1 : 2);
+		bits = cpu_to_be64((u64)rctx->total << 3); /* needs num of bits */
+		memcpy(final_blocks + total_pad - 8, &bits, 8);
+		for (i = 0; i < total_pad; i += SHA256_BLOCK_SIZE) {
+			ret = atmel_i2c_init_sha_cmd(cmd, final_blocks + i,
+						     SHA256_BLOCK_SIZE,
+						     atmel_sha_compute, &data->timings);
+			if (ret)
+				goto err_or_done;
+
+			ret = _atmel_i2c_send_receive(ctx->client, cmd);
+			if (ret)
+				goto err_or_done;
+		}
+	} else {
+		ret = atmel_i2c_init_sha_cmd(cmd, rctx->buffer, rctx->bufcnt,
+					     atmel_sha_ecc_end, &data->timings);
+		if (ret)
+			goto err_or_done;
+
+		ret = _atmel_i2c_send_receive(ctx->client, cmd);
+		if (ret)
+			goto err_or_done;
+	}
+
+	memcpy(req->result, &cmd->data[ATMEL_I2C_RSP_DATA_IDX],
+	       SHA256_DIGEST_SIZE);
+
+	/* Sleep returns a positive int on success, API requires 0 on success */
+	ret = atmel_i2c_sleep(ctx->client);
+	if (ret < 0)
+		goto err_or_done;
+	ret = 0;
+err_or_done:
+	kfree_sensitive(cmd);
+err_nomem:
+	mutex_unlock(&i2c_priv->lock);
+	return ret;
+}
+EXPORT_SYMBOL(atmel_i2c_sha_final);
+
+int atmel_i2c_sha_finup(struct ahash_request *req)
+{
+	return atmel_i2c_sha_update(req) ? : atmel_i2c_sha_final(req);
+}
+EXPORT_SYMBOL(atmel_i2c_sha_finup);
+
+int atmel_i2c_sha_digest(struct ahash_request *req)
+{
+	return atmel_i2c_sha_init(req) ? : atmel_i2c_sha_finup(req);
+}
+EXPORT_SYMBOL(atmel_i2c_sha_digest);
+
+int atmel_i2c_sha_export(struct ahash_request *req, void *out)
+{
+	memcpy(out, ahash_request_ctx(req), sizeof(struct atmel_i2c_sha_reqctx));
+	return 0;
+}
+EXPORT_SYMBOL(atmel_i2c_sha_export);
+
+int atmel_i2c_sha_import(struct ahash_request *req, const void *in)
+{
+	memcpy(ahash_request_ctx(req), in, sizeof(struct atmel_i2c_sha_reqctx));
+	return 0;
+}
+EXPORT_SYMBOL(atmel_i2c_sha_import);
+
 static void atmel_i2c_work_handler(struct work_struct *work)
 {
 	struct atmel_i2c_work_data *work_data =
diff --git a/drivers/crypto/atmel-i2c.h b/drivers/crypto/atmel-i2c.h
index 20afe2da4f8d..e0021d4ea686 100644
--- a/drivers/crypto/atmel-i2c.h
+++ b/drivers/crypto/atmel-i2c.h
@@ -7,8 +7,11 @@
 #ifndef __ATMEL_I2C_H__
 #define __ATMEL_I2C_H__
 
+#include <linux/device.h>
+#include <crypto/internal/hash.h>
 #include <linux/hw_random.h>
 #include <linux/types.h>
+#include <crypto/sha2.h>
 
 #define ATMEL_I2C_PRIORITY		300
 
@@ -79,11 +82,13 @@ struct atmel_i2c_max_exec_timings {
 	unsigned int max_exec_time_ecdh;
 	unsigned int max_exec_time_random;
 	unsigned int max_exec_time_read;
+	unsigned int max_exec_time_sha;
 	unsigned int max_exec_time_write;
 };
 
 struct atmel_i2c_of_match_data {
 	const unsigned short needs_legacy_hwrng;
+	const unsigned short needs_sha_padding;
 	struct atmel_i2c_max_exec_timings timings;
 	size_t eeprom_zone_size[3]; /* all atmel devices have three zones */
 };
@@ -91,6 +96,30 @@ struct atmel_i2c_of_match_data {
 /* Used for binding tfm objects to i2c clients. */
 enum atmel_i2c_capability {
 	ATMEL_CAP_ECDH = 0,
+	ATMEL_CAP_SHA,
+};
+
+enum atmel_i2c_sha_engine_cmd {
+	atmel_sha_init = 0,
+	atmel_sha_compute,
+	atmel_sha_ecc_end,
+};
+
+size_t atmel_i2c_sha_rsp_size[] = {
+	[atmel_sha_init] = ATMEL_I2C_STATUS_RSP_SIZE,
+	[atmel_sha_compute] = SHA256_DIGEST_SIZE + ATMEL_I2C_RSP_OVERHEAD_SIZE,
+	[atmel_sha_ecc_end] = SHA256_DIGEST_SIZE + ATMEL_I2C_RSP_OVERHEAD_SIZE,
+};
+
+struct atmel_i2c_sha_ctx {
+	struct i2c_client *client;
+};
+
+struct atmel_i2c_sha_reqctx {
+	u8 buffer[SHA256_BLOCK_SIZE];
+	size_t bufcnt;
+	size_t total; /* size of full input, needed for padding */
+	struct atmel_i2c_client_priv *ctx;
 };
 
 struct atmel_i2c_client_mgmt {
@@ -172,9 +201,20 @@ void atmel_i2c_init_genkey_cmd(struct atmel_i2c_cmd *cmd, u16 keyid,
 int atmel_i2c_init_ecdh_cmd(struct atmel_i2c_cmd *cmd,
 			    struct scatterlist *pubkey,
 			    const struct atmel_i2c_max_exec_timings *timings);
+int atmel_i2c_init_sha_cmd(struct atmel_i2c_cmd *cmd, u8 *challenge, size_t len,
+			   enum atmel_i2c_sha_engine_cmd sha_engine_cmd,
+			   const struct atmel_i2c_max_exec_timings *timings);
 int atmel_i2c_register_rng(struct atmel_i2c_client_priv *i2c_priv,
 			   struct device *dev);
 
+int atmel_i2c_sha_init(struct ahash_request *req);
+int atmel_i2c_sha_update(struct ahash_request *req);
+int atmel_i2c_sha_final(struct ahash_request *req);
+int atmel_i2c_sha_finup(struct ahash_request *req);
+int atmel_i2c_sha_digest(struct ahash_request *req);
+int atmel_i2c_sha_export(struct ahash_request *req, void *out);
+int atmel_i2c_sha_import(struct ahash_request *req, const void *in);
+
 int atmel_i2c_device_sanity_check(struct i2c_client *client);
 
 ssize_t atmel_i2c_eeprom_display(struct device *dev,
diff --git a/drivers/crypto/atmel-sha204a.c b/drivers/crypto/atmel-sha204a.c
index 6a41024ae40d..74535480edeb 100644
--- a/drivers/crypto/atmel-sha204a.c
+++ b/drivers/crypto/atmel-sha204a.c
@@ -17,8 +17,48 @@
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/workqueue.h>
+#include <crypto/sha2.h>
+
 #include "atmel-i2c.h"
 
+static int atmel_sha204a_sha_init_tfm(struct crypto_tfm *tfm)
+{
+	struct atmel_i2c_sha_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->client = atmel_i2c_client_alloc(ATMEL_CAP_SHA);
+	if (IS_ERR(ctx->client)) {
+		pr_err("tfm - i2c_client binding failed\n");
+		return PTR_ERR(ctx->client);
+	}
+
+	return 0;
+}
+
+static struct ahash_alg atmel_sha204a_sha = {
+	.init = atmel_i2c_sha_init,
+	.update	= atmel_i2c_sha_update,
+	.final = atmel_i2c_sha_final,
+	.finup = atmel_i2c_sha_finup,
+	.digest	= atmel_i2c_sha_digest,
+	.export = atmel_i2c_sha_export,
+	.import = atmel_i2c_sha_import,
+	.halg = {
+		.digestsize = SHA256_DIGEST_SIZE,
+		.statesize = sizeof(struct atmel_i2c_sha_reqctx),
+		.base = {
+			.cra_name		= "sha256",
+			.cra_driver_name	= "atmel-sha256",
+			.cra_init		= atmel_sha204a_sha_init_tfm,
+			.cra_priority		= ATMEL_I2C_PRIORITY,
+			.cra_flags		= CRYPTO_ALG_TYPE_AHASH,
+			.cra_blocksize		= SHA256_BLOCK_SIZE,
+			.cra_ctxsize		= sizeof(struct atmel_i2c_sha_ctx),
+			.cra_reqsize		= sizeof(struct atmel_i2c_sha_reqctx),
+			.cra_module		= THIS_MODULE,
+		}
+	}
+};
+
 static ssize_t config_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	return atmel_i2c_eeprom_display(dev, attr, buf, ATMEL_EEPROM_CONFIG_ZONE);
@@ -62,7 +102,7 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 
 	i2c_priv = i2c_get_clientdata(client);
 	i2c_priv->data = data;
-	i2c_priv->caps = 0;
+	i2c_priv->caps = BIT(ATMEL_CAP_SHA);
 
 	ret = atmel_i2c_device_sanity_check(client);
 	if (ret) {
@@ -95,6 +135,13 @@ static int atmel_sha204a_probe(struct i2c_client *client)
 		goto err_list_del;
 	}
 
+	/* register algorithms */
+	ret = crypto_register_ahash(&atmel_sha204a_sha);
+	if (ret) {
+		dev_err(&client->dev, "SHA256 registration failed\n");
+		goto err_list_del;
+	}
+
 	goto done;
 
 err_list_del:
@@ -119,6 +166,8 @@ static void atmel_sha204a_remove(struct i2c_client *client)
 	devm_hwrng_unregister(&client->dev, &i2c_priv->hwrng);
 	atmel_i2c_flush_queue();
 
+	crypto_unregister_ahash(&atmel_sha204a_sha);
+
 	if (i2c_priv->hwrng.priv) {
 		kfree((void *)i2c_priv->hwrng.priv);
 		i2c_priv->hwrng.priv = 0;
@@ -130,6 +179,7 @@ static const struct atmel_i2c_of_match_data atsha204_match_data = {
 		.max_exec_time_genkey = 43,
 		.max_exec_time_random = 50,
 		.max_exec_time_read = 4,
+		.max_exec_time_sha = 22,
 		.max_exec_time_write = 42,
 	},
 	.eeprom_zone_size = {
@@ -142,6 +192,7 @@ static const struct atmel_i2c_of_match_data atsha204_match_data = {
 	 * [1] https://www.metzdowd.com/pipermail/cryptography/2014-December/023858.html
 	 */
 	.needs_legacy_hwrng = 1,
+	.needs_sha_padding = 1,
 };
 
 static const struct atmel_i2c_of_match_data atsha204a_match_data = {
@@ -149,6 +200,7 @@ static const struct atmel_i2c_of_match_data atsha204a_match_data = {
 		.max_exec_time_genkey = 43,
 		.max_exec_time_random = 50,
 		.max_exec_time_read = 4,
+		.max_exec_time_sha = 22,
 		.max_exec_time_write = 42,
 	},
 	.eeprom_zone_size = {
@@ -156,6 +208,7 @@ static const struct atmel_i2c_of_match_data atsha204a_match_data = {
 		[ATMEL_EEPROM_OTP_ZONE] = 64,
 		[ATMEL_EEPROM_DATA_ZONE] = 512
 	},
+	.needs_sha_padding = 1,
 };
 
 static const struct of_device_id atmel_sha204a_dt_ids[] __maybe_unused = {
-- 
2.53.0