This reads out the serial number of the crypto chip and prints it,
also toss this into the entropy pool as it is device-unique data.
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v1->v2:
- kfree(cmd) was missed. Fix it with a goto construction.
- Coding style fixes.
---
drivers/crypto/atmel-ecc.c | 60 ++++++++++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/drivers/crypto/atmel-ecc.c b/drivers/crypto/atmel-ecc.c
index f3322fae454e..659cb3cf37a9 100644
--- a/drivers/crypto/atmel-ecc.c
+++ b/drivers/crypto/atmel-ecc.c
@@ -26,6 +26,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
+#include <linux/random.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
@@ -610,6 +611,61 @@ static inline size_t atmel_ecc_wake_token_sz(u32 bus_clk_rate)
return DIV_ROUND_UP(no_of_bits, 8);
}
+static int atmel_ecc_get_serial(struct i2c_client *client)
+{
+ struct atmel_ecc_cmd *cmd;
+ int ret;
+ int i;
+ u8 serial[9];
+
+ cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
+ if (!cmd)
+ return -ENOMEM;
+
+ atmel_ecc_init_read_config_word(cmd, CONFIG_ZONE_SERIAL_0_3);
+ ret = atmel_ecc_send_receive(client, cmd);
+ if (ret) {
+ dev_err(&client->dev,
+ "failed to read serial byte 0-3\n");
+ goto out_free_cmd;
+ }
+ for (i = 0; i < 4; i++)
+ serial[i] = cmd->data[RSP_DATA_IDX + i];
+
+ atmel_ecc_init_read_config_word(cmd, CONFIG_ZONE_SERIAL_4_7);
+ ret = atmel_ecc_send_receive(client, cmd);
+ if (ret) {
+ dev_err(&client->dev,
+ "failed to read serial byte 4-7\n");
+ goto out_free_cmd;
+ }
+ for (i = 0; i < 4; i++)
+ serial[4 + i] = cmd->data[RSP_DATA_IDX + i];
+
+
+ atmel_ecc_init_read_config_word(cmd, CONFIG_ZONE_SERIAL_8_I2CEN);
+ ret = atmel_ecc_send_receive(client, cmd);
+ if (ret) {
+ kfree(cmd);
+ dev_err(&client->dev,
+ "failed to read serial byte 8\n");
+ goto out_free_cmd;
+ }
+ serial[8] = cmd->data[RSP_DATA_IDX];
+
+ /* This is device-unique data so it goes into the entropy pool */
+ add_device_randomness(serial, sizeof(serial));
+
+ dev_info(&client->dev,
+ "serial number: %02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
+ serial[0], serial[1], serial[2], serial[3], serial[4],
+ serial[5], serial[6], serial[7], serial[8]);
+
+out_free_cmd:
+ kfree(cmd);
+ return ret;
+}
+
static int device_sanity_check(struct i2c_client *client)
{
struct atmel_ecc_cmd *cmd;
@@ -692,6 +748,10 @@ static int atmel_ecc_probe(struct i2c_client *client,
if (ret)
return ret;
+ ret = atmel_ecc_get_serial(client);
+ if (ret)
+ return ret;
+
spin_lock(&driver_data.i2c_list_lock);
list_add_tail(&i2c_priv->i2c_client_list_node,
&driver_data.i2c_client_list);
--
2.17.0
