drivers: tpm: atmel_twi: implement get_desc operation

Without get_desc, the tpm command will not provide a
description of the device in 'tpm device' or 'tpm info'.

Due to the characteristics of the Atmel TPM it isn't
possible to determine certain attributes (e.g open/close
status) without using the TPM stack (compare Infineon
and ST TPM drivers), so just print out the chip model
and udevice name as the identifier.

Signed-off-by: Mathew McBride <matt@traverse.com.au>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

diff --git a/drivers/tpm/tpm_atmel_twi.c b/drivers/tpm/tpm_atmel_twi.c
index 71b1014..a5dfb34 100644 (file)
--- a/drivers/tpm/tpm_atmel_twi.c
+++ b/drivers/tpm/tpm_atmel_twi.c
@@ -52,7 +52,10 @@ static int tpm_atmel_twi_close(struct udevice *dev)
  */
 static int tpm_atmel_twi_get_desc(struct udevice *dev, char *buf, int size)
 {
-       return 0;
+       if (size < 50)
+               return -ENOSPC;
+
+       return snprintf(buf, size, "Atmel AT97SC3204T I2C 1.2 TPM (%s)", dev->name);
 }
 
 /*