tis.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <console/console.h>
#include <security/tpm/tis.h>
#include <acpi/acpigen.h>
#include <device/device.h>
#include <drivers/intel/ptt/ptt.h>
 
#include "tpm.h"
#include "chip.h"
 
static unsigned int tpm_is_open;
 
static const struct {
        uint16_t vid;
        uint16_t did;
        const char *device_name;
} dev_map[] = {
        {0x1ae0, 0x0028, "CR50"},
        {0xa13a, 0x8086, "Intel iTPM"}
};
 
static const char *tis_get_dev_name(struct tpm2_info *info)
{
        int i;
 
        for (i = 0; i < ARRAY_SIZE(dev_map); i++)
                if ((dev_map[i].vid == info->vendor_id) && (dev_map[i].did == info->device_id))
                        return dev_map[i].device_name;
        return "Unknown";
}
 
int tis_open(void)
{
        if (tpm_is_open) {
                printk(BIOS_ERR, "%s called twice.\n", __func__);
                return -1;
        }
 
        if (CONFIG(HAVE_INTEL_PTT)) {
                if (!ptt_active()) {
                        printk(BIOS_ERR, "%s: Intel PTT is not active.\n", __func__);
                        return -1;
                }
                printk(BIOS_DEBUG, "%s: Intel PTT is active.\n", __func__);
        }
 
        return 0;
}
 
int tis_close(void)
{
        if (tpm_is_open) {
 
                /*
                 * Do we need to do something here, like waiting for a
                 * transaction to stop?
                 */
                tpm_is_open = 0;
        }
 
        return 0;
}
 
int tis_init(void)
{
        struct tpm2_info info;
 
        // Wake TPM up (if necessary)
        if (tpm2_init() != 0)
                return -1;
 
        tpm2_get_info(&info);
 
        printk(BIOS_INFO, "Initialized TPM device %s revision %d\n", tis_get_dev_name(&info),
               info.revision);
 
        return 0;
}
 
int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size, uint8_t *recvbuf, size_t *rbuf_len)
{
        int len = tpm2_process_command(sendbuf, sbuf_size, recvbuf, *rbuf_len);
 
        if (len == 0)
                return -1;
 
        *rbuf_len = len;
 
        return 0;
}
 
static void crb_tpm_fill_ssdt(const struct device *dev)
{
        const char *path = acpi_device_path(dev);
        if (!path) {
                path = "\\_SB_.TPM";
                printk(BIOS_DEBUG, "Using default TPM2 ACPI path: '%s'\n", path);
        }
 
        /* Device */
        acpigen_write_device(path);
 
        acpigen_write_name_string("_HID", "MSFT0101");
        acpigen_write_name_string("_CID", "MSFT0101");
 
        acpi_device_write_uid(dev);
 
        acpigen_write_STA(ACPI_STATUS_DEVICE_ALL_ON);
 
        /* Resources */
        acpigen_write_name("_CRS");
        acpigen_write_resourcetemplate_header();
        acpigen_write_mem32fixed(1, TPM_CRB_BASE_ADDRESS, 0x5000);
 
        acpigen_write_resourcetemplate_footer();
 
        acpigen_pop_len(); /* Device */
}
 
static const char *crb_tpm_acpi_name(const struct device *dev)
{
        return "TPM";
}
 
static struct device_operations __unused crb_ops = {
        .read_resources = noop_read_resources,
        .set_resources = noop_set_resources,
#if CONFIG(HAVE_ACPI_TABLES)
        .acpi_name = crb_tpm_acpi_name,
        .acpi_fill_ssdt = crb_tpm_fill_ssdt,
#endif
 
};
 
static void enable_dev(struct device *dev)
{
#if !DEVTREE_EARLY
        dev->ops = &crb_ops;
#endif
}
 
struct chip_operations drivers_crb_ops = {
        CHIP_NAME("CRB TPM")
        .enable_dev = enable_dev
};