tpm: Add 'tpm autostart' shell command

For a TPM device to be operational we need to initialize it and
perform its startup sequence.  The 'tpm init' command currently calls
tpm_init() which ends up calling the ->open() per-device callback and
performs the initial hardware configuration as well as requesting
locality 0 for the caller.  There no code that currently calls
tpm_init() without following up with a tpm_startup() and tpm_self_test_full()
or tpm_continue_self_test().

So let's add a 'tpm autostart' command and call tpm_auto_start() which
leaves the device in an operational state.

It's worth noting that calling tpm_init() only, doesn't allow a someone
to use the TPM since the startup sequence is mandatory. We always
repeat the pattern of calling
- tpm_init()
- tpm_startup()
- tpm_self_test_full() or tpm_continue_self_test()

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/cmd/tpm-common.c b/cmd/tpm-common.c
index d0c63cadf4..a7dc23d85d 100644
--- a/cmd/tpm-common.c
+++ b/cmd/tpm-common.c
@@ -11,6 +11,7 @@
 #include <asm/unaligned.h>
 #include <linux/string.h>
 #include <tpm-common.h>
+#include <tpm_api.h>
 #include "tpm-user-utils.h"
 
 static struct udevice *tpm_dev;
@@ -367,6 +368,21 @@ int do_tpm_init(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	return report_return_code(tpm_init(dev));
 }
 
+int do_tpm_autostart(struct cmd_tbl *cmdtp, int flag, int argc,
+		     char *const argv[])
+{
+	struct udevice *dev;
+	int rc;
+
+	if (argc != 1)
+		return CMD_RET_USAGE;
+	rc = get_tpm(&dev);
+	if (rc)
+		return rc;
+
+	return report_return_code(tpm_auto_start(dev));
+}
+
 int do_tpm(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	struct cmd_tbl *tpm_commands, *cmd;