From: "Bart Groeneveld | GPX Solutions B.V." <bart@xxxxxxxx> The specification [1] allows so-called HW-reduced platforms, which do not implement everything, especially the wakeup related stuff. In that case, it is still usable as a RTC. This is helpful for [2] and [3], which is about a device with no other working RTC, but it does have an HW-reduced TAD, which can be used as a RTC instead. [1]: https://uefi.org/specs/ACPI/6.5/09_ACPI_Defined_Devices_and_Device_Specific_Objects.html#time-and-alarm-device [2]: https://bugzilla.kernel.org/show_bug.cgi?id=212313 [3]: https://github.com/linux-surface/linux-surface/issues/415 Signed-off-by: Bart Groeneveld | GPX Solutions B.V. <bart@xxxxxxxx> --- drivers/acpi/acpi_tad.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c index e9b8e8305e23..944276934e7e 100644 --- a/drivers/acpi/acpi_tad.c +++ b/drivers/acpi/acpi_tad.c @@ -432,6 +432,14 @@ static ssize_t caps_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RO(caps); +static struct attribute *acpi_tad_attrs[] = { + &dev_attr_caps.attr, + NULL, +}; +static const struct attribute_group acpi_tad_attr_group = { + .attrs = acpi_tad_attrs, +}; + static ssize_t ac_alarm_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { @@ -480,15 +488,14 @@ static ssize_t ac_status_show(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RW(ac_status); -static struct attribute *acpi_tad_attrs[] = { - &dev_attr_caps.attr, +static struct attribute *acpi_tad_ac_attrs[] = { &dev_attr_ac_alarm.attr, &dev_attr_ac_policy.attr, &dev_attr_ac_status.attr, NULL, }; -static const struct attribute_group acpi_tad_attr_group = { - .attrs = acpi_tad_attrs, +static const struct attribute_group acpi_tad_ac_attr_group = { + .attrs = acpi_tad_ac_attrs, }; static ssize_t dc_alarm_store(struct device *dev, struct device_attribute *attr, @@ -563,13 +570,18 @@ static int acpi_tad_remove(struct platform_device *pdev) pm_runtime_get_sync(dev); + if (dd->capabilities & ACPI_TAD_AC_WAKE) + sysfs_remove_group(&dev->kobj, &acpi_tad_ac_attr_group); + if (dd->capabilities & ACPI_TAD_DC_WAKE) sysfs_remove_group(&dev->kobj, &acpi_tad_dc_attr_group); sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group); - acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER); - acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER); + if (dd->capabilities & ACPI_TAD_AC_WAKE) { + acpi_tad_disable_timer(dev, ACPI_TAD_AC_TIMER); + acpi_tad_clear_status(dev, ACPI_TAD_AC_TIMER); + } if (dd->capabilities & ACPI_TAD_DC_WAKE) { acpi_tad_disable_timer(dev, ACPI_TAD_DC_TIMER); acpi_tad_clear_status(dev, ACPI_TAD_DC_TIMER); @@ -604,11 +616,6 @@ static int acpi_tad_probe(struct platform_device *pdev) return -ENODEV; } - if (!acpi_has_method(handle, "_PRW")) { - dev_info(dev, "Missing _PRW\n"); - return -ENODEV; - } - dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL); if (!dd) return -ENOMEM; @@ -637,6 +644,12 @@ static int acpi_tad_probe(struct platform_device *pdev) if (ret) goto fail; + if (caps & ACPI_TAD_AC_WAKE) { + ret = sysfs_create_group(&dev->kobj, &acpi_tad_ac_attr_group); + if (ret) + goto fail; + } + if (caps & ACPI_TAD_DC_WAKE) { ret = sysfs_create_group(&dev->kobj, &acpi_tad_dc_attr_group); if (ret) -- 2.38.1
