diff options
Diffstat (limited to 'drivers/tpm/cr50_i2c.c')
| -rw-r--r-- | drivers/tpm/cr50_i2c.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/tpm/cr50_i2c.c b/drivers/tpm/cr50_i2c.c index f8c3087894..acf4c7859a 100644 --- a/drivers/tpm/cr50_i2c.c +++ b/drivers/tpm/cr50_i2c.c @@ -13,11 +13,13 @@ #include <irq.h> #include <log.h> #include <spl.h> +#include <tpm-common.h> #include <tpm-v2.h> #include <acpi/acpigen.h> #include <acpi/acpi_device.h> #include <asm/gpio.h> #include <asm/io.h> +#include <asm/unaligned.h> #include <linux/delay.h> #include <dm/acpi.h> @@ -37,6 +39,50 @@ enum { CR50_MAX_BUF_SIZE = 63, }; +/* + * Operations specific to the Cr50 TPM used on Chromium OS and Android devices + * + * FIXME: below is not enough to differentiate between vendors commands + * of numerous devices. However, the current tpm2 APIs aren't very amenable + * to extending generically because the marshaling code is assuming all + * knowledge of all commands. + */ +#define TPM2_CC_VENDOR_BIT_MASK 0x20000000 + +#define TPM2_CR50_VENDOR_COMMAND (TPM2_CC_VENDOR_BIT_MASK | 0) +#define TPM2_CR50_SUB_CMD_IMMEDIATE_RESET 19 +#define TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS 21 +#define TPM2_CR50_SUB_CMD_REPORT_TPM_STATE 23 +#define TPM2_CR50_SUB_CMD_TURN_UPDATE_ON 24 +#define TPM2_CR50_SUB_CMD_GET_REC_BTN 29 +#define TPM2_CR50_SUB_CMD_TPM_MODE 40 +#define TPM2_CR50_SUB_CMD_GET_BOOT_MODE 52 +#define TPM2_CR50_SUB_CMD_RESET_EC 53 + +/* Cr50 vendor-specific error codes. */ +#define VENDOR_RC_ERR 0x00000500 +enum cr50_vendor_rc { + VENDOR_RC_INTERNAL_ERROR = (VENDOR_RC_ERR | 6), + VENDOR_RC_NO_SUCH_SUBCOMMAND = (VENDOR_RC_ERR | 8), + VENDOR_RC_NO_SUCH_COMMAND = (VENDOR_RC_ERR | 127), +}; + +enum cr50_tpm_mode { + /* + * Default state: TPM is enabled, and may be set to either + * TPM_MODE_ENABLED or TPM_MODE_DISABLED. + */ + TPM_MODE_ENABLED_TENTATIVE = 0, + + /* TPM is enabled, and mode may not be changed. */ + TPM_MODE_ENABLED = 1, + + /* TPM is disabled, and mode may not be changed. */ + TPM_MODE_DISABLED = 2, + + TPM_MODE_INVALID, +}; + /** * struct cr50_priv - Private driver data * @@ -54,6 +100,41 @@ struct cr50_priv { bool use_irq; }; +/* + * The below structure represents the body of the response to the 'report tpm + * state' vendor command. + * + * It is transferred over the wire, so it needs to be serialized/deserialized, + * and it is likely to change, so its contents must be versioned. + */ +#define TPM_STATE_VERSION 1 +struct tpm_vendor_state { + u32 version; + /* + * The following three fields are set by the TPM in case of an assert. + * There is no other processing than setting the source code line + * number, error code and the first 4 characters of the function name. + * + * We don't expect this happening, but it is included in the report + * just in case. + */ + u32 fail_line; /* s_failLIne */ + u32 fail_code; /* s_failCode */ + char func_name[4]; /* s_failFunction, limited to 4 chars */ + + /* + * The following two fields are the current time filtered value of the + * 'failed tries' TPM counter, and the maximum allowed value of the + * counter. + * + * failed_tries == max_tries is the definition of the TPM lockout + * condition. + */ + u32 failed_tries; /* gp.failedTries */ + u32 max_tries; /* gp.maxTries */ + /* The below fields are present in version 2 and above */ +}; + /* Wait for interrupt to indicate TPM is ready */ static int cr50_i2c_wait_tpm_ready(struct udevice *dev) { @@ -573,6 +654,87 @@ static int cr50_i2c_get_desc(struct udevice *dev, char *buf, int size) return len; } +static int stringify_state(char *buf, int len, char *str, size_t max_size) +{ + struct tpm_vendor_state state; + size_t text_size = 0; + + state.version = get_unaligned_be32(buf + + offsetof(struct tpm_vendor_state, version)); + state.fail_line = get_unaligned_be32(buf + + offsetof(struct tpm_vendor_state, fail_line)); + state.fail_code = get_unaligned_be32(buf + + offsetof(struct tpm_vendor_state, fail_code)); + memcpy(state.func_name, + buf + offsetof(struct tpm_vendor_state, func_name), + sizeof(state.func_name)); + state.failed_tries = get_unaligned_be32(buf + + offsetof(struct tpm_vendor_state, failed_tries)); + state.max_tries = get_unaligned_be32(buf + + offsetof(struct tpm_vendor_state, max_tries)); + + text_size += snprintf(str + text_size, max_size - text_size, + "v=%d", state.version); + if (text_size >= max_size) + return -ENOSPC; + + if (state.version > TPM_STATE_VERSION) + text_size += snprintf(str + text_size, + max_size - text_size, + " not fully supported\n"); + if (text_size >= max_size) + return -ENOSPC; + + if (state.version == 0) + return -EINVAL; /* This should never happen */ + + text_size += snprintf(str + text_size, + max_size - text_size, + " failed_tries=%d max_tries=%d\n", + state.failed_tries, state.max_tries); + if (text_size >= max_size) + return -ENOSPC; + + if (state.fail_line) { + /* make sure function name is zero terminated. */ + char func_name[sizeof(state.func_name) + 1]; + + memcpy(func_name, state.func_name, sizeof(state.func_name)); + func_name[sizeof(state.func_name)] = '\0'; + + text_size += snprintf(str + text_size, + max_size - text_size, + "tpm failed: f %s line %d code %d", + func_name, + state.fail_line, + state.fail_code); + if (text_size >= max_size) + return -ENOSPC; + } + + return 0; +} + +static int cr50_i2c_report_state(struct udevice *dev, char *str, int str_max) +{ + char buf[50]; + size_t buf_size = sizeof(buf); + int ret; + + ret = tpm2_report_state(dev, TPM2_CR50_VENDOR_COMMAND, + TPM2_CR50_SUB_CMD_REPORT_TPM_STATE, + buf, &buf_size); + if (ret) + return ret; + + /* TPM responded as expected */ + ret = stringify_state(buf, buf_size, str, str_max); + if (ret) + return ret; + + return 0; +} + static int cr50_i2c_open(struct udevice *dev) { char buf[80]; @@ -730,6 +892,7 @@ struct acpi_ops cr50_acpi_ops = { static const struct tpm_ops cr50_i2c_ops = { .open = cr50_i2c_open, .get_desc = cr50_i2c_get_desc, + .report_state = cr50_i2c_report_state, .send = cr50_i2c_send, .recv = cr50_i2c_recv, .cleanup = cr50_i2c_cleanup, |