[PATCH v2 5/6] drivers: tpm: atmel_twi: implement get_desc operation

[Mathew McBride]

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 at traverse.com.au>
---
 drivers/tpm/tpm_atmel_twi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/tpm/tpm_atmel_twi.c b/drivers/tpm/tpm_atmel_twi.c
index 71b101406d..a5dfb34846 100644
--- 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);
 }
 
 /*
-- 
2.30.1