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![Hans de Goede](/assets/img/avatar_default.png)
Drivers like thinkpad_acpi and ideapad_laptop call the platform_profile_notify() helper when the profile is changed by hardware (the embedded-controller/EC) in response to an EC handled hotkey. This allows userspace to monitor for such changes by polling for POLLPRI on the platform_profile sysfs file. But the profile can also be changed underneath a userspace program monitoring it by anonther userspace program storing a new value. Add a sysfs_notify() call to platform_profile_store(), so that userspace programs monitoring for changes also get notified in this case. Also update the documentation to document that POLLPRI polling can be used to watch for changes. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
181 lines
4.1 KiB
C
181 lines
4.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Platform profile sysfs interface */
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#include <linux/acpi.h>
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#include <linux/bits.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/platform_profile.h>
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#include <linux/sysfs.h>
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static struct platform_profile_handler *cur_profile;
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static DEFINE_MUTEX(profile_lock);
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static const char * const profile_names[] = {
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[PLATFORM_PROFILE_LOW_POWER] = "low-power",
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[PLATFORM_PROFILE_COOL] = "cool",
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[PLATFORM_PROFILE_QUIET] = "quiet",
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[PLATFORM_PROFILE_BALANCED] = "balanced",
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[PLATFORM_PROFILE_BALANCED_PERFORMANCE] = "balanced-performance",
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[PLATFORM_PROFILE_PERFORMANCE] = "performance",
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};
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static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
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static ssize_t platform_profile_choices_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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int len = 0;
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int err, i;
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err = mutex_lock_interruptible(&profile_lock);
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if (err)
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return err;
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if (!cur_profile) {
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mutex_unlock(&profile_lock);
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return -ENODEV;
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}
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for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
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if (len == 0)
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len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
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else
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len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
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}
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len += sysfs_emit_at(buf, len, "\n");
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mutex_unlock(&profile_lock);
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return len;
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}
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static ssize_t platform_profile_show(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
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int err;
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err = mutex_lock_interruptible(&profile_lock);
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if (err)
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return err;
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if (!cur_profile) {
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mutex_unlock(&profile_lock);
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return -ENODEV;
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}
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err = cur_profile->profile_get(cur_profile, &profile);
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mutex_unlock(&profile_lock);
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if (err)
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return err;
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/* Check that profile is valid index */
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if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
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return -EIO;
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return sysfs_emit(buf, "%s\n", profile_names[profile]);
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}
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static ssize_t platform_profile_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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int err, i;
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err = mutex_lock_interruptible(&profile_lock);
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if (err)
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return err;
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if (!cur_profile) {
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mutex_unlock(&profile_lock);
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return -ENODEV;
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}
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/* Scan for a matching profile */
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i = sysfs_match_string(profile_names, buf);
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if (i < 0) {
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mutex_unlock(&profile_lock);
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return -EINVAL;
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}
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/* Check that platform supports this profile choice */
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if (!test_bit(i, cur_profile->choices)) {
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mutex_unlock(&profile_lock);
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return -EOPNOTSUPP;
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}
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err = cur_profile->profile_set(cur_profile, i);
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if (!err)
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sysfs_notify(acpi_kobj, NULL, "platform_profile");
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mutex_unlock(&profile_lock);
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if (err)
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return err;
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return count;
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}
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static DEVICE_ATTR_RO(platform_profile_choices);
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static DEVICE_ATTR_RW(platform_profile);
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static struct attribute *platform_profile_attrs[] = {
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&dev_attr_platform_profile_choices.attr,
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&dev_attr_platform_profile.attr,
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NULL
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};
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static const struct attribute_group platform_profile_group = {
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.attrs = platform_profile_attrs
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};
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void platform_profile_notify(void)
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{
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if (!cur_profile)
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return;
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sysfs_notify(acpi_kobj, NULL, "platform_profile");
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}
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EXPORT_SYMBOL_GPL(platform_profile_notify);
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int platform_profile_register(struct platform_profile_handler *pprof)
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{
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int err;
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mutex_lock(&profile_lock);
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/* We can only have one active profile */
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if (cur_profile) {
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mutex_unlock(&profile_lock);
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return -EEXIST;
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}
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/* Sanity check the profile handler field are set */
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if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
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!pprof->profile_set || !pprof->profile_get) {
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mutex_unlock(&profile_lock);
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return -EINVAL;
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}
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err = sysfs_create_group(acpi_kobj, &platform_profile_group);
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if (err) {
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mutex_unlock(&profile_lock);
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return err;
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}
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cur_profile = pprof;
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mutex_unlock(&profile_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(platform_profile_register);
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int platform_profile_remove(void)
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{
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sysfs_remove_group(acpi_kobj, &platform_profile_group);
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mutex_lock(&profile_lock);
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cur_profile = NULL;
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mutex_unlock(&profile_lock);
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return 0;
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}
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EXPORT_SYMBOL_GPL(platform_profile_remove);
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MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
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MODULE_LICENSE("GPL");
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