From 557e1a729a9ca89e814220b6203b7ac0dc446913 Mon Sep 17 00:00:00 2001 From: Duncan Laurie Date: Mon, 19 Sep 2016 17:09:01 -0700 Subject: [PATCH] drivers/i2c/tpm/cr50: Clean up locality functions Clean up the mask and timeout handling in the locality functions that were copied from the original driver. BUG=chrome-os-partner:53336 Change-Id: Ifa1445224b475aec38c2ac56e15cb7ba7fcd21ea Signed-off-by: Duncan Laurie --- src/drivers/i2c/tpm/cr50.c | 39 +++++++++++++++++++------------------- 1 file changed, 20 insertions(+), 19 deletions(-) diff --git a/src/drivers/i2c/tpm/cr50.c b/src/drivers/i2c/tpm/cr50.c index fbc3ece09b..a3ff7814de 100644 --- a/src/drivers/i2c/tpm/cr50.c +++ b/src/drivers/i2c/tpm/cr50.c @@ -137,13 +137,13 @@ static int cr50_i2c_write(struct tpm_chip *chip, static int check_locality(struct tpm_chip *chip, int loc) { + uint8_t mask = TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY; uint8_t buf; if (cr50_i2c_read(chip, TPM_ACCESS(loc), &buf, 1) < 0) return -1; - if ((buf & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) == - (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) { + if ((buf & mask) == mask) { chip->vendor.locality = loc; return loc; } @@ -151,40 +151,41 @@ static int check_locality(struct tpm_chip *chip, int loc) return -1; } -static void release_locality(struct tpm_chip *chip, int loc, int force) +static void release_locality(struct tpm_chip *chip, int force) { + uint8_t mask = TPM_ACCESS_VALID | TPM_ACCESS_REQUEST_PENDING; + uint8_t addr = TPM_ACCESS(chip->vendor.locality); uint8_t buf; - if (cr50_i2c_read(chip, TPM_ACCESS(loc), &buf, 1) < 0) + if (cr50_i2c_read(chip, addr, &buf, 1) < 0) return; - if (force || (buf & (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) == - (TPM_ACCESS_REQUEST_PENDING | TPM_ACCESS_VALID)) { + if (force || (buf & mask) == mask) { buf = TPM_ACCESS_ACTIVE_LOCALITY; - cr50_i2c_write(chip, TPM_ACCESS(loc), &buf, 1); + cr50_i2c_write(chip, addr, &buf, 1); } + + chip->vendor.locality = 0; } static int request_locality(struct tpm_chip *chip, int loc) { uint8_t buf = TPM_ACCESS_REQUEST_USE; + struct stopwatch sw; if (check_locality(chip, loc) >= 0) - return loc; /* we already have the locality */ + return loc; if (cr50_i2c_write(chip, TPM_ACCESS(loc), &buf, 1) < 0) return -1; - /* wait for burstcount */ - int timeout = 2 * 1000; /* 2s timeout */ - while (timeout) { - if (check_locality(chip, loc) >= 0) - return loc; - mdelay(TPM_TIMEOUT); - timeout--; + stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_LONG_MS); + while (check_locality(chip, loc) < 0) { + if (stopwatch_expired(&sw)) + return -1; + mdelay(CR50_TIMEOUT_SHORT_MS); } - - return -1; + return loc; } /* cr50 requires all 4 bytes of status register to be read */ @@ -458,11 +459,11 @@ int tpm_vendor_init(struct tpm_chip *chip, unsigned bus, uint32_t dev_addr) return 0; out_err: - release_locality(chip, 0, 1); + release_locality(chip, 1); return -1; } void tpm_vendor_cleanup(struct tpm_chip *chip) { - release_locality(chip, chip->vendor.locality, 1); + release_locality(chip, 1); }