ACPI: TAD: Support RTC without wakeup

The ACPI TAD can provide a functional RTC without wakeup capabilities,
so stop failing probe if AC wakeup is not supported.

Also, if _PRW is missing, do not fail probe, but clear the wakeup bits
in capabilities.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/1959268.tdWV9SEqCh@rafael.j.wysocki

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
index 78d0bee4b28aec1400ebd63bbba0da4d3bfa638d..560ed6495daf6894c065299774d5a1946b051a87 100644 (file)
--- a/drivers/acpi/acpi_tad.c
+++ b/drivers/acpi/acpi_tad.c
@@ -546,8 +546,9 @@ static umode_t acpi_tad_attr_is_visible(struct kobject *kobj,
        if (a == &dev_attr_caps.attr)
                return a->mode;
 
-       if (a == &dev_attr_ac_alarm.attr || a == &dev_attr_ac_policy.attr ||
-           a == &dev_attr_ac_status.attr)
+       if ((dd->capabilities & ACPI_TAD_AC_WAKE) &&
+           (a == &dev_attr_ac_alarm.attr || a == &dev_attr_ac_policy.attr ||
+            a == &dev_attr_ac_status.attr))
                return a->mode;
 
        if ((dd->capabilities & ACPI_TAD_DC_WAKE) &&
@@ -581,8 +582,10 @@ static void acpi_tad_remove(struct platform_device *pdev)
        sysfs_remove_group(&dev->kobj, &acpi_tad_attr_group);
 
        scoped_guard(pm_runtime_noresume, dev) {
-               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);
@@ -612,14 +615,9 @@ static int acpi_tad_probe(struct platform_device *pdev)
                return -ENODEV;
        }
 
-       if (!(caps & ACPI_TAD_AC_WAKE)) {
-               dev_info(dev, "Unsupported capabilities\n");
-               return -ENODEV;
-       }
-
        if (!acpi_has_method(handle, "_PRW")) {
                dev_info(dev, "Missing _PRW\n");
-               return -ENODEV;
+               caps &= ~(ACPI_TAD_AC_WAKE | ACPI_TAD_DC_WAKE);
        }
 
        dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
@@ -635,9 +633,11 @@ static int acpi_tad_probe(struct platform_device *pdev)
         * runtime suspend.  Everything else should be taken care of by the ACPI
         * PM domain callbacks.
         */
-       device_init_wakeup(dev, true);
-       dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
-                                    DPM_FLAG_MAY_SKIP_RESUME);
+       if (ACPI_TAD_AC_WAKE | ACPI_TAD_DC_WAKE) {
+               device_init_wakeup(dev, true);
+               dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
+                                            DPM_FLAG_MAY_SKIP_RESUME);
+       }
 
        /*
         * The platform bus type layer tells the ACPI PM domain powers up the