Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750991AbdCMFWr (ORCPT ); Mon, 13 Mar 2017 01:22:47 -0400 Received: from mail5.windriver.com ([192.103.53.11]:60992 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750916AbdCMFWg (ORCPT ); Mon, 13 Mar 2017 01:22:36 -0400 From: To: CC: , , , , Subject: [PATCH] tpm: Add sysfs interface to show TPM hardware version Date: Mon, 13 Mar 2017 13:21:57 +0800 Message-ID: <1489382517-9078-1-git-send-email-Meng.Li@windriver.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3086 Lines: 123 From: Limeng So far, there is not a sysfs interface for user space code to check the TPM hardware version(TPM1.x or TPM2). So, add a file named description in /sys/class/tpm/tpmX/ to show it. Signed-off-by: Meng Li --- drivers/char/tpm/tpm-chip.c | 85 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index c406343..da2cd69 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -36,6 +36,83 @@ dev_t tpm_devt; /** + * show_description - sysfs interface for checking current TPM hardware version. + * @dev: pointer to tpm chip device + * @attr: unused + * @buf: char buffer to be filled with TPM hardware version info + * + * Provides sysfs interface for showing current TPM hardware version. + */ +static ssize_t show_description(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tpm_chip *chip = (struct tpm_chip *)container_of(dev,struct tpm_chip,dev); + int ret; + + if (chip->flags & TPM_CHIP_FLAG_TPM2) + ret = sprintf(buf, "TPM 2.0"); + else + ret = sprintf(buf, "TPM 1.x"); + + return ret; +} + +/** + * store_description - interface for manually setting data. + * @dev: unused + * @attr: unused + * @buf: unused + * @count: unused + * + * There is not any process in this function, reserve for feature. + */ +static ssize_t store_description(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + return count; +} + +static struct device_attribute tpm_attrs[] = { + __ATTR(description, S_IRUGO | S_IWUSR, show_description, store_description), +}; + +/** + * tpm_create_sysfs - Create tpm sysfs interface. + * @dev: pointer to tpm chip device + * + * Create sysfs interface for checking current TPM hardware version. + */ +static int tpm_create_sysfs(struct device *dev) +{ + int r, t; + + for (t = 0; t < ARRAY_SIZE(tpm_attrs); t++) { + r = device_create_file(dev, &tpm_attrs[t]); + if (r) { + dev_err(dev, "failed to create sysfs file\n"); + return r; + } + } + + return 0; +} + +/** + * tpm_remove_sysfs - Remove tpm sysfs interface. + * @dev: pointer to tpm chip device + * + * Remove sysfs interface for checking current TPM hardware version. + */ +static void tpm_remove_sysfs(struct device *dev) +{ + int t; + + for (t = 0; t < ARRAY_SIZE(tpm_attrs); t++) { + device_remove_file(dev, &tpm_attrs[t]); + } +} + +/** * tpm_try_get_ops() - Get a ref to the tpm_chip * @chip: Chip to ref * @@ -363,6 +440,13 @@ int tpm_chip_register(struct tpm_chip *chip) return rc; } + rc = tpm_create_sysfs(&chip->dev); + if (rc) { + tpm_del_legacy_sysfs(chip); + tpm_chip_unregister(chip); + return rc; + } + return 0; } EXPORT_SYMBOL_GPL(tpm_chip_register); @@ -382,6 +466,7 @@ int tpm_chip_register(struct tpm_chip *chip) */ void tpm_chip_unregister(struct tpm_chip *chip) { + tpm_remove_sysfs(&chip->dev); tpm_del_legacy_sysfs(chip); tpm_bios_log_teardown(chip); tpm_del_char_device(chip); -- 1.7.9.5