src/security/tpm/tis.h

/* SPDX-License-Identifier: GPL-2.0-only */

#ifndef TIS_H_
#define TIS_H_

#include <types.h>

enum tis_access {
	TPM_ACCESS_VALID = (1 << 7),
	TPM_ACCESS_ACTIVE_LOCALITY = (1 << 5),
	TPM_ACCESS_REQUEST_PENDING = (1 << 2),
	TPM_ACCESS_REQUEST_USE = (1 << 1),
	TPM_ACCESS_ESTABLISHMENT = (1 << 0),
};

enum tis_status {
	TPM_STS_FAMILY_SHIFT = 26,
	TPM_STS_FAMILY_MASK = (0x3 << TPM_STS_FAMILY_SHIFT),
	TPM_STS_FAMILY_TPM_2_0 = (1 << TPM_STS_FAMILY_SHIFT),
	TPM_STS_FAMILY_TPM_1_2 = (0 << TPM_STS_FAMILY_SHIFT),
	TPM_STS_RESET_ESTABLISHMENT = (1 << 25),
	TPM_STS_COMMAND_CANCEL = (1 << 24),
	TPM_STS_BURST_COUNT_SHIFT = 8,
	TPM_STS_BURST_COUNT_MASK = (0xFFFF << TPM_STS_BURST_COUNT_SHIFT),
	TPM_STS_VALID = (1 << 7),
	TPM_STS_COMMAND_READY = (1 << 6),
	TPM_STS_GO = (1 << 5),
	TPM_STS_DATA_AVAIL = (1 << 4),
	TPM_STS_DATA_EXPECT = (1 << 3),
	TPM_STS_SELF_TEST_DONE = (1 << 2),
	TPM_STS_RESPONSE_RETRY = (1 << 1),
};

/*
 * tis_init()
 *
 * Initialize the TPM device. Returns 0 on success or -1 on
 * failure (in case device probing did not succeed).
 */
int tis_init(void);

/*
 * tis_open()
 *
 * Requests access to locality 0 for the caller.
 *
 * Returns 0 on success, -1 on failure.
 */
int tis_open(void);

/*
 * tis_sendrecv()
 *
 * Send the requested data to the TPM and then try to get its response
 *
 * @sendbuf - buffer of the data to send
 * @send_size size of the data to send
 * @recvbuf - memory to save the response to
 * @recv_len - pointer to the size of the response buffer
 *
 * Returns 0 on success (and places the number of response bytes at recv_len)
 * or -1 on failure.
 */
int tis_sendrecv(const u8 *sendbuf, size_t send_size, u8 *recvbuf,
			size_t *recv_len);

/* TODO: This is supposed to be used only for Google TPM.
   Consider moving this to drivers/tpm/cr50.h. */
/*
 * tis_plat_irq_status()
 *
 * Check tpm irq and clear it.
 *
 * Returns 1 when irq pending or 0 when not.
 */
int tis_plat_irq_status(void);

/*
 * tis_vendor_write()
 *
 * Vendor-specific function to send the requested data to the TPM.
 *
 * @addr - address of the register to write to
 * @sendbuf - buffer of the data to send
 * @send_size - size of the data to send
 *
 * Returns CB_SUCCESS 0 on success, CB_ERR on failure.
 */
enum cb_err tis_vendor_write(unsigned int addr, const void *sendbuf, size_t send_size);

/*
 * tis_vendor_read()
 *
 * Vendor-specific function to read the requested data from the TPM.
 *
 * @addr - address of the register to read from
 * @recvbuf - buffer of the data to read
 * @recv_size - size of the output buffer
 *
 * Returns CB_SUCCESS on success or -1 on failure.
 */
enum cb_err tis_vendor_read(unsigned int addr, void *recvbuf, size_t recv_size);

static inline bool tpm_first_access_this_boot(void)
{
	return ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK || !CONFIG(VBOOT);
}

#endif /* TIS_H_ */