Messages in this thread Patch in this message | | | From | Enric Balletbo i Serra <> | Subject | [PATCH 1/3] platform/chrome: cros_ec_debugfs: Add debugfs entry to retrieve EC uptime | Date | Fri, 14 Jun 2019 13:15:49 +0200 |
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From: Tim Wawrzynczak <twawrzynczak@chromium.org>
The new debugfs entry 'uptime' is being made available to userspace so that a userspace daemon can synchronize EC logs with host time.
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org> [rework based on Tim's first approach] Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> --- Hi Tim,
Sorry for beating around the bush a bit. I did a small rework of the latest patch you sent and now is more close to the first versions you sent. I was spinning around the idea if we should expose the attribute when the command is supported or not and I ended with the conclusion, however, I think makes sense for sysfs attributes, but I'd prefer simplicity in the code for debugfs, at the end, if we try to read a file for a non supported command we will get an error which is also useful debug information.
Could you recheck that the patch still works and that I didn't break anything, please?
Cheers, ~ Enric
Documentation/ABI/testing/debugfs-cros-ec | 8 +++++ drivers/platform/chrome/cros_ec_debugfs.c | 38 +++++++++++++++++++++++ 2 files changed, 46 insertions(+) create mode 100644 Documentation/ABI/testing/debugfs-cros-ec
diff --git a/Documentation/ABI/testing/debugfs-cros-ec b/Documentation/ABI/testing/debugfs-cros-ec new file mode 100644 index 000000000000..c91da2d374aa --- /dev/null +++ b/Documentation/ABI/testing/debugfs-cros-ec @@ -0,0 +1,8 @@ +What: /sys/kernel/debug/<cros-ec-device>/uptime +Date: June 2019 +KernelVersion: 5.3 +Description: + A u32 providing the time since EC booted in ms. This is + is used for synchronizing the AP host time with the EC + log. An error is returned if the command is not supported + by the EC or there is a communication problem. diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c index 4578eb3e0731..970ba13df9a1 100644 --- a/drivers/platform/chrome/cros_ec_debugfs.c +++ b/drivers/platform/chrome/cros_ec_debugfs.c @@ -241,6 +241,34 @@ static ssize_t cros_ec_pdinfo_read(struct file *file, read_buf, p - read_buf); } +static ssize_t cros_ec_uptime_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct cros_ec_debugfs *debug_info = file->private_data; + struct cros_ec_device *ec_dev = debug_info->ec->ec_dev; + struct { + struct cros_ec_command cmd; + struct ec_response_uptime_info resp; + } __packed msg = {}; + struct ec_response_uptime_info *resp; + char read_buf[32]; + int ret; + + resp = (struct ec_response_uptime_info *)&msg.resp; + + msg.cmd.command = EC_CMD_GET_UPTIME_INFO; + msg.cmd.insize = sizeof(*resp); + + ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd); + if (ret < 0) + return ret; + + ret = scnprintf(read_buf, sizeof(read_buf), "%u\n", + resp->time_since_ec_boot_ms); + + return simple_read_from_buffer(user_buf, count, ppos, read_buf, ret); +} + static const struct file_operations cros_ec_console_log_fops = { .owner = THIS_MODULE, .open = cros_ec_console_log_open, @@ -257,6 +285,13 @@ static const struct file_operations cros_ec_pdinfo_fops = { .llseek = default_llseek, }; +const struct file_operations cros_ec_uptime_fops = { + .owner = THIS_MODULE, + .open = simple_open, + .read = cros_ec_uptime_read, + .llseek = default_llseek, +}; + static int ec_read_version_supported(struct cros_ec_dev *ec) { struct ec_params_get_cmd_versions_v1 *params; @@ -408,6 +443,9 @@ static int cros_ec_debugfs_probe(struct platform_device *pd) debugfs_create_file("pdinfo", 0444, debug_info->dir, debug_info, &cros_ec_pdinfo_fops); + debugfs_create_file("uptime", 0444, debug_info->dir, debug_info, + &cros_ec_uptime_fops); + ec->debug_info = debug_info; dev_set_drvdata(&pd->dev, ec); -- 2.20.1
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