Messages in this thread Patch in this message | | | From | RaviChandra Sadineni <> | Subject | [PATCH V2] cros_ec: Expose sysfile to force battery cut-off on shutdown. | Date | Sun, 3 Mar 2019 16:54:14 -0800 |
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On chromebooks, power_manager daemon normally shutsdown(S5) the device when the battery charge falls below 4% threshold. Chromeos EC then normally spends an hour in S5 before hibernating. If the battery charge falls below critical threshold in the mean time, EC does a battery cutoff instead of hibernating. On some chromebooks, S5 is optimal enough resulting in EC hibernating without battery cut-off. This results in battery deep-discharging. This is a bad user experience as battery has to trickle charge before booting when the A.C is plugged in the next time.
This patch exposes a sysfs file for an userland daemon to suggest EC if it has to do a battery cut-off instead of hibernating when the system enters S5 next time.
Signed-off-by: RaviChandra Sadineni <ravisadineni@chromium.org> --- V2: Use kstrtobool() instead of kstrtou8() and add documentation.
.../ABI/testing/sysfs-class-chromeos | 8 ++++ drivers/platform/chrome/cros_ec_sysfs.c | 37 +++++++++++++++++++ 2 files changed, 45 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-chromeos
diff --git a/Documentation/ABI/testing/sysfs-class-chromeos b/Documentation/ABI/testing/sysfs-class-chromeos new file mode 100644 index 000000000000..44d3cee6e7ae --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-chromeos @@ -0,0 +1,8 @@ +What: /sys/class/chromeos/cros_ec/cutoff_at_shutdown +Date: February 2019 +Contact: Ravi Chandra Sadineni <ravisadineni@chromium.org> +Description: + On writing '[Yy1]' to cutoff_at_shutdown property, + kernel sends a host command to EC requesting battery + cutoff on next shutdown. If AC is plugged in before + next shutdown, EC resets this flag. diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c index f34a50121064..f5168ce8bfc7 100644 --- a/drivers/platform/chrome/cros_ec_sysfs.c +++ b/drivers/platform/chrome/cros_ec_sysfs.c @@ -322,14 +322,51 @@ static ssize_t kb_wake_angle_store(struct device *dev, return count; } +/* Battery cut-off control */ +static ssize_t cutoff_at_shutdown_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ec_params_battery_cutoff *param; + struct cros_ec_command *msg; + int ret; + struct cros_ec_dev *ec = container_of( + dev, struct cros_ec_dev, class_dev); + bool cutoff_battery; + + if (kstrtobool(buf, &cutoff_battery)) + return -EINVAL; + + if (!cutoff_battery) + return count; + + msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + param = (struct ec_params_battery_cutoff *)msg->data; + msg->command = EC_CMD_BATTERY_CUT_OFF + ec->cmd_offset; + msg->version = 1; + param->flags = EC_BATTERY_CUTOFF_FLAG_AT_SHUTDOWN; + msg->outsize = sizeof(*param); + msg->insize = 0; + ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg); + kfree(msg); + if (ret < 0) + return ret; + return count; +} + /* Module initialization */ static DEVICE_ATTR_RW(reboot); static DEVICE_ATTR_RO(version); static DEVICE_ATTR_RO(flashinfo); static DEVICE_ATTR_RW(kb_wake_angle); +static DEVICE_ATTR_WO(cutoff_at_shutdown); static struct attribute *__ec_attrs[] = { + &dev_attr_cutoff_battery_at_shutdown.attr, &dev_attr_kb_wake_angle.attr, &dev_attr_reboot.attr, &dev_attr_version.attr, -- 2.20.1
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