| /* SPDX-License-Identifier: BSD-3-Clause */ |
| |
| #include <drivers/spi/tpm/tpm.h> |
| #include <security/tpm/tis.h> |
| #include <string.h> |
| #include <timer.h> |
| #include <types.h> |
| |
| #define CR50_DID_VID 0x00281ae0L |
| #define TI50_DID_VID 0x504a6666L |
| |
| #define CR50_BOARD_CFG_LOCKBIT_MASK 0x80000000U |
| #define CR50_BOARD_CFG_FEATUREBITS_MASK 0x3FFFFFFFU |
| |
| #define CR50_BOARD_CFG_100US_READY_PULSE 0x00000001U |
| #define CR50_BOARD_CFG_VALUE \ |
| (CONFIG(CR50_USE_LONG_INTERRUPT_PULSES) \ |
| ? CR50_BOARD_CFG_100US_READY_PULSE : 0) |
| |
| enum cr50_register { |
| CR50_FW_VER_REG, |
| CR50_BOARD_CFG_REG, |
| }; |
| |
| #define CR50_FW_VER_REG_SPI (TPM_LOCALITY_0_SPI_BASE + 0xf90) |
| #define CR50_BOARD_CFG_REG_SPI (TPM_LOCALITY_0_SPI_BASE + 0xfe0) |
| |
| #define CR50_FW_VER_REG_I2C 0x0f |
| #define CR50_BOARD_CFG_REG_I2C 0x1c |
| |
| /* Return register address, which depends on the bus type, or -1 for error. */ |
| static int get_reg_addr(enum cr50_register reg) |
| { |
| if (CONFIG(SPI_TPM)) { |
| switch (reg) { |
| case CR50_FW_VER_REG: |
| return CR50_FW_VER_REG_SPI; |
| case CR50_BOARD_CFG_REG: |
| return CR50_BOARD_CFG_REG_SPI; |
| default: |
| return -1; |
| } |
| } |
| |
| if (CONFIG(I2C_TPM)) { |
| switch (reg) { |
| case CR50_FW_VER_REG: |
| return CR50_FW_VER_REG_I2C; |
| case CR50_BOARD_CFG_REG: |
| return CR50_BOARD_CFG_REG_I2C; |
| default: |
| return -1; |
| } |
| } |
| |
| return -1; |
| } |
| |
| static bool cr50_fw_supports_board_cfg(struct cr50_firmware_version *version) |
| { |
| /* Cr50 supports the CR50_BOARD_CFG register from version 0.5.5 / 0.6.5 |
| * and onwards. */ |
| if (version->epoch > 0 || version->major >= 7 |
| || (version->major >= 5 && version->minor >= 5)) |
| return true; |
| |
| printk(BIOS_INFO, "Cr50 firmware does not support CR50_BOARD_CFG, version: %d.%d.%d\n", |
| version->epoch, version->major, version->minor); |
| |
| return false; |
| } |
| |
| /* |
| * Expose method to read the CR50_BOARD_CFG register, will return zero if |
| * register not supported by Cr50 firmware. |
| */ |
| static uint32_t cr50_get_board_cfg(void) |
| { |
| struct cr50_firmware_version ver; |
| uint32_t value; |
| |
| if (cr50_get_firmware_version(&ver) != CB_SUCCESS) |
| return 0; |
| |
| if (!cr50_fw_supports_board_cfg(&ver)) |
| return 0; |
| |
| const enum cb_err ret = tis_vendor_read(get_reg_addr(CR50_BOARD_CFG_REG), &value, |
| sizeof(value)); |
| if (ret != CB_SUCCESS) { |
| printk(BIOS_ERR, "Error reading from Cr50\n"); |
| return 0; |
| } |
| |
| return value & CR50_BOARD_CFG_FEATUREBITS_MASK; |
| } |
| |
| /** |
| * Set the BOARD_CFG register on the TPM chip to a particular compile-time constant value. |
| */ |
| enum cb_err cr50_set_board_cfg(void) |
| { |
| /* If we get here and we aren't cr50, then we must be ti50 which does |
| * not currently need to support a board_cfg register. */ |
| if (!CONFIG(TPM_GOOGLE_CR50)) |
| return CB_SUCCESS; |
| |
| struct cr50_firmware_version ver; |
| enum cb_err ret; |
| uint32_t value; |
| |
| if (cr50_get_firmware_version(&ver) != CB_SUCCESS) |
| return CB_ERR; |
| |
| if (!cr50_fw_supports_board_cfg(&ver)) |
| return CB_ERR; |
| |
| /* Set the CR50_BOARD_CFG register, for e.g. asking cr50 to use longer ready pulses. */ |
| ret = tis_vendor_read(get_reg_addr(CR50_BOARD_CFG_REG), &value, sizeof(value)); |
| if (ret != CB_SUCCESS) { |
| printk(BIOS_ERR, "Error reading from Cr50\n"); |
| return CB_ERR; |
| } |
| |
| if ((value & CR50_BOARD_CFG_FEATUREBITS_MASK) == CR50_BOARD_CFG_VALUE) { |
| printk(BIOS_INFO, "Current CR50_BOARD_CFG = 0x%08x, matches desired = 0x%08x\n", |
| value, CR50_BOARD_CFG_VALUE); |
| return CB_SUCCESS; |
| } |
| |
| if (value & CR50_BOARD_CFG_LOCKBIT_MASK) { |
| /* The high bit is set, meaning that the Cr50 is already locked on a particular |
| * value for the register, but not the one we wanted. */ |
| printk(BIOS_ERR, "Current CR50_BOARD_CFG = 0x%08x, does not match" |
| "desired = 0x%08x\n", value, CR50_BOARD_CFG_VALUE); |
| return CB_ERR; |
| } |
| |
| printk(BIOS_INFO, "Current CR50_BOARD_CFG = 0x%08x, setting to 0x%08x\n", |
| value, CR50_BOARD_CFG_VALUE); |
| value = CR50_BOARD_CFG_VALUE; |
| |
| ret = tis_vendor_write(get_reg_addr(CR50_BOARD_CFG_REG), &value, sizeof(value)); |
| if (ret != CB_SUCCESS) { |
| printk(BIOS_ERR, "Error writing to cr50\n"); |
| return ret; |
| } |
| |
| return CB_SUCCESS; |
| } |
| |
| bool cr50_is_long_interrupt_pulse_enabled(void) |
| { |
| if (CONFIG(TPM_GOOGLE_CR50)) |
| return !!(cr50_get_board_cfg() & CR50_BOARD_CFG_100US_READY_PULSE); |
| |
| /* Ti50 and future GSCs will support only long interrupt pulses. */ |
| return true; |
| } |
| |
| static enum cb_err cr50_parse_fw_version(const char *version_str, |
| struct cr50_firmware_version *ver) |
| { |
| int epoch, major, minor; |
| |
| char *number = strstr(version_str, " RW_A:"); |
| if (!number) |
| number = strstr(version_str, " RW_B:"); |
| if (!number) |
| return CB_ERR_ARG; |
| number += 6; /* Skip past the colon. */ |
| |
| epoch = skip_atoi(&number); |
| if (*number++ != '.') |
| return CB_ERR_ARG; |
| major = skip_atoi(&number); |
| if (*number++ != '.') |
| return CB_ERR_ARG; |
| minor = skip_atoi(&number); |
| |
| ver->epoch = epoch; |
| ver->major = major; |
| ver->minor = minor; |
| return CB_SUCCESS; |
| } |
| |
| enum cb_err cr50_get_firmware_version(struct cr50_firmware_version *version) |
| { |
| static struct cr50_firmware_version cr50_firmware_version; |
| |
| if (cr50_firmware_version.epoch || cr50_firmware_version.major || |
| cr50_firmware_version.minor) |
| goto success; |
| |
| int chunk_count = 0; |
| size_t chunk_size = 50; |
| char version_str[301]; |
| int addr = get_reg_addr(CR50_FW_VER_REG); |
| |
| /* |
| * Does not really matter what's written, this just makes sure |
| * the version is reported from the beginning. |
| */ |
| tis_vendor_write(addr, &chunk_size, 1); |
| |
| /* |
| * Read chunk_size bytes at a time, last chunk will be zero padded. |
| */ |
| do { |
| uint8_t *buf = (uint8_t *)version_str + chunk_count * chunk_size; |
| tis_vendor_read(addr, buf, chunk_size); |
| if (!version_str[++chunk_count * chunk_size - 1]) |
| /* Zero padding detected: end of string. */ |
| break; |
| /* Check if there is enough room for reading one more chunk. */ |
| } while (chunk_count * chunk_size < sizeof(version_str) - chunk_size); |
| |
| version_str[chunk_count * chunk_size] = '\0'; |
| printk(BIOS_INFO, "Firmware version: %s\n", version_str); |
| |
| if (cr50_parse_fw_version(version_str, &cr50_firmware_version) != CB_SUCCESS) { |
| printk(BIOS_ERR, "Did not recognize Cr50 version format\n"); |
| return CB_ERR; |
| } |
| |
| success: |
| if (version) |
| *version = cr50_firmware_version; |
| return CB_SUCCESS; |
| } |
| |
| enum cb_err cr50_wait_tpm_ready(void) |
| { |
| struct stopwatch sw; |
| |
| stopwatch_init_msecs_expire(&sw, CONFIG_GOOGLE_TPM_IRQ_TIMEOUT_MS); |
| |
| while (!tis_plat_irq_status()) |
| if (stopwatch_expired(&sw)) { |
| printk(BIOS_ERR, "Cr50 TPM IRQ timeout!\n"); |
| return CB_ERR; |
| } |
| |
| return CB_SUCCESS; |
| } |