platform/x86/amd/pmf: Add sysfs to toggle CnQF

Whether to turn CnQF on/off by default upon driver load would be decided
by a BIOS flag. Add a sysfs node to provide a way to the user whether to
use static slider or CnQF .

Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Shyam Sundar S K <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Hans de Goede <[e-mail]>

drivers/platform/x86/amd/pmf/cnqf.c

···
 	return 0;
 }
 
+static ssize_t cnqf_enable_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct amd_pmf_dev *pdev = dev_get_drvdata(dev);
+	int mode, result, src;
+	bool input;
+
+	mode = amd_pmf_get_pprof_modes(pdev);
+	if (mode < 0)
+		return mode;
+
+	result = kstrtobool(buf, &input);
+	if (result)
+		return result;
+
+	src = amd_pmf_cnqf_get_power_source(pdev);
+	pdev->cnqf_enabled = input;
+
+	if (pdev->cnqf_enabled && pdev->current_profile == PLATFORM_PROFILE_BALANCED) {
+		amd_pmf_set_cnqf(pdev, src, config_store.current_mode, NULL);
+	} else {
+		if (is_apmf_func_supported(pdev, APMF_FUNC_STATIC_SLIDER_GRANULAR))
+			amd_pmf_update_slider(pdev, SLIDER_OP_SET, mode, NULL);
+	}
+
+	dev_dbg(pdev->dev, "Received CnQF %s\n", input ? "on" : "off");
+	return count;
+}
+
+static ssize_t cnqf_enable_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct amd_pmf_dev *pdev = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", pdev->cnqf_enabled ? "on" : "off");
+}
+
+static DEVICE_ATTR_RW(cnqf_enable);
+
+static umode_t cnqf_feature_is_visible(struct kobject *kobj,
+				       struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct amd_pmf_dev *pdev = dev_get_drvdata(dev);
+
+	return pdev->cnqf_supported ? attr->mode : 0;
+}
+
+static struct attribute *cnqf_feature_attrs[] = {
+	&dev_attr_cnqf_enable.attr,
+	NULL
+};
+
+const struct attribute_group cnqf_feature_attribute_group = {
+	.is_visible = cnqf_feature_is_visible,
+	.attrs = cnqf_feature_attrs,
+};
+
 void amd_pmf_deinit_cnqf(struct amd_pmf_dev *dev)
 {
 	cancel_delayed_work_sync(&dev->work_buffer);

drivers/platform/x86/amd/pmf/core.c

···
 	return 0;
 }
 
+static const struct attribute_group *amd_pmf_driver_groups[] = {
+	&cnqf_feature_attribute_group,
+	NULL,
+};
+
 static struct platform_driver amd_pmf_driver = {
 	.driver = {
 		.name = "amd-pmf",
 		.acpi_match_table = amd_pmf_acpi_ids,
+		.dev_groups = amd_pmf_driver_groups,
 	},
 	.probe = amd_pmf_probe,
 	.remove = amd_pmf_remove,

drivers/platform/x86/amd/pmf/pmf.h

···
 int amd_pmf_init_cnqf(struct amd_pmf_dev *dev);
 void amd_pmf_deinit_cnqf(struct amd_pmf_dev *dev);
 int amd_pmf_trans_cnqf(struct amd_pmf_dev *dev, int socket_power, ktime_t time_lapsed_ms);
+extern const struct attribute_group cnqf_feature_attribute_group;
 
 #endif /* PMF_H */