diff options
Diffstat (limited to 'drivers/char/tpm/tpm-chip.c')
| -rw-r--r-- | drivers/char/tpm/tpm-chip.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 157505b0f755..ed673c7216a0 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -37,6 +37,117 @@ struct class *tpm_class; struct class *tpmrm_class; dev_t tpm_devt; +static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags) +{ + int rc; + + if (flags & TPM_TRANSMIT_NESTED) + return 0; + + if (!chip->ops->request_locality) + return 0; + + rc = chip->ops->request_locality(chip, 0); + if (rc < 0) + return rc; + + chip->locality = rc; + return 0; +} + +static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags) +{ + int rc; + + if (flags & TPM_TRANSMIT_NESTED) + return; + + if (!chip->ops->relinquish_locality) + return; + + rc = chip->ops->relinquish_locality(chip, chip->locality); + if (rc) + dev_err(&chip->dev, "%s: : error %d\n", __func__, rc); + + chip->locality = -1; +} + +static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags) +{ + if (flags & TPM_TRANSMIT_NESTED) + return 0; + + if (!chip->ops->cmd_ready) + return 0; + + return chip->ops->cmd_ready(chip); +} + +static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags) +{ + if (flags & TPM_TRANSMIT_NESTED) + return 0; + + if (!chip->ops->go_idle) + return 0; + + return chip->ops->go_idle(chip); +} + +/** + * tpm_chip_start() - power on the TPM + * @chip: a TPM chip to use + * @flags: TPM transmit flags + * + * Return: + * * The response length - OK + * * -errno - A system error + */ +int tpm_chip_start(struct tpm_chip *chip, unsigned int flags) +{ + int ret; + + if (chip->ops->clk_enable) + chip->ops->clk_enable(chip, true); + + if (chip->locality == -1) { + ret = tpm_request_locality(chip, flags); + if (ret) { + chip->ops->clk_enable(chip, false); + return ret; + } + } + + ret = tpm_cmd_ready(chip, flags); + if (ret) { + tpm_relinquish_locality(chip, flags); + if (chip->ops->clk_enable) + chip->ops->clk_enable(chip, false); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(tpm_chip_start); + +/** + * tpm_chip_stop() - power off the TPM + * @chip: a TPM chip to use + * @flags: TPM transmit flags + * + * Return: + * * The response length - OK + * * -errno - A system error + */ +void tpm_chip_stop(struct tpm_chip *chip, unsigned int flags) +{ + tpm_go_idle(chip, flags); + tpm_relinquish_locality(chip, flags); + if (chip->ops->clk_enable) + chip->ops->clk_enable(chip, false); +} +EXPORT_SYMBOL_GPL(tpm_chip_stop); + /** * tpm_try_get_ops() - Get a ref to the tpm_chip * @chip: Chip to ref |