drivers/tpm: Move PPI stub
As preparation to a full PPI implementation move the acpi code out
of the pc80/tpm/tis driver into the generic tpm driver folder.
This doesn't change any functionality.
Change-Id: I7818d0344d4a08926195bd4804565502717c48fa
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45567
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/drivers/tpm/ppi_stub.c b/src/drivers/tpm/ppi_stub.c
new file mode 100644
index 0000000..11bd07e
--- /dev/null
+++ b/src/drivers/tpm/ppi_stub.c
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <types.h>
+#include <stddef.h>
+#include <acpi/acpi.h>
+#include <acpi/acpigen.h>
+#include <acpi/acpi_device.h>
+
+#include "tpm_ppi.h"
+
+static void tpm_ppi_func0_cb(void *arg)
+{
+ /* Functions 1-8. */
+ u8 buf[] = {0xff, 0x01};
+ acpigen_write_return_byte_buffer(buf, sizeof(buf));
+}
+
+static void tpm_ppi_func1_cb(void *arg)
+{
+ if (CONFIG(TPM2))
+ /* Interface version: 2.0 */
+ acpigen_write_return_string("2.0");
+ else
+ /* Interface version: 1.2 */
+ acpigen_write_return_string("1.2");
+}
+
+static void tpm_ppi_func2_cb(void *arg)
+{
+ /* Submit operations: drop on the floor and return success. */
+ acpigen_write_return_byte(PPI2_RET_SUCCESS);
+}
+
+static void tpm_ppi_func3_cb(void *arg)
+{
+ /* Pending operation: none. */
+ acpigen_emit_byte(RETURN_OP);
+ acpigen_write_package(2);
+ acpigen_write_byte(0);
+ acpigen_write_byte(0);
+ acpigen_pop_len();
+}
+
+static void tpm_ppi_func4_cb(void *arg)
+{
+ /* Pre-OS transition method: reboot. */
+ acpigen_write_return_byte(2);
+}
+
+static void tpm_ppi_func5_cb(void *arg)
+{
+ /* Operation response: no operation executed. */
+ acpigen_emit_byte(RETURN_OP);
+ acpigen_write_package(3);
+ acpigen_write_byte(0);
+ acpigen_write_byte(0);
+ acpigen_write_byte(0);
+ acpigen_pop_len();
+}
+
+static void tpm_ppi_func6_cb(void *arg)
+{
+ /*
+ * Set preferred user language: deprecated and must return 3 AKA
+ * "not implemented".
+ */
+ acpigen_write_return_byte(PPI6_RET_NOT_IMPLEMENTED);
+}
+
+static void tpm_ppi_func7_cb(void *arg)
+{
+ /* Submit operations: deny. */
+ acpigen_write_return_byte(PPI7_RET_BLOCKED_BY_FIRMWARE);
+}
+
+static void tpm_ppi_func8_cb(void *arg)
+{
+ /* All actions are forbidden. */
+ acpigen_write_return_byte(PPI8_RET_FIRMWARE_ONLY);
+}
+
+static void (*tpm_ppi_callbacks[])(void *) = {
+ tpm_ppi_func0_cb,
+ tpm_ppi_func1_cb,
+ tpm_ppi_func2_cb,
+ tpm_ppi_func3_cb,
+ tpm_ppi_func4_cb,
+ tpm_ppi_func5_cb,
+ tpm_ppi_func6_cb,
+ tpm_ppi_func7_cb,
+ tpm_ppi_func8_cb,
+};
+
+static void tpm_mci_func0_cb(void *arg)
+{
+ /* Function 1. */
+ acpigen_write_return_singleton_buffer(0x3);
+}
+static void tpm_mci_func1_cb(void *arg)
+{
+ /* Just return success. */
+ acpigen_write_return_byte(0);
+}
+
+static void (*tpm_mci_callbacks[])(void *) = {
+ tpm_mci_func0_cb,
+ tpm_mci_func1_cb,
+};
+
+void tpm_ppi_acpi_fill_ssdt(const struct device *dev)
+{
+ /*
+ * _DSM method
+ */
+ struct dsm_uuid ids[] = {
+ /* Physical presence interface.
+ * This is used to submit commands like "Clear TPM" to
+ * be run at next reboot provided that user confirms
+ * them. Spec allows user to cancel all commands and/or
+ * configure BIOS to reject commands. So we pretend that
+ * user did just this: cancelled everything. If user
+ * really wants to clear TPM the only option now is to
+ * do it manually in payload.
+ */
+ DSM_UUID(TPM_PPI_UUID, tpm_ppi_callbacks,
+ ARRAY_SIZE(tpm_ppi_callbacks), NULL),
+ /* Memory clearing on boot: just a dummy. */
+ DSM_UUID(TPM_MCI_UUID, tpm_mci_callbacks,
+ ARRAY_SIZE(tpm_mci_callbacks), NULL),
+ };
+
+ acpigen_write_dsm_uuid_arr(ids, ARRAY_SIZE(ids));
+}