[PATCH 3/5] platform/x86: asus-bioscfg: add apu-mem control support

["Luke D. Jones" <luke@ljones.dev>]

Implement the APU memory size control under the asus-bioscfg module using
the fw_attributes class.

This allows the APU allocated memory size to be adjusted depending on
the users priority. A reboot is required after change.

Signed-off-by: Luke D. Jones <luke@ljones.dev>
---
 drivers/platform/x86/asus-bioscfg.c        | 116 +++++++++++++++++++++
 include/linux/platform_data/x86/asus-wmi.h |   1 +
 2 files changed, 117 insertions(+)

diff --git a/drivers/platform/x86/asus-bioscfg.c b/drivers/platform/x86/asus-bioscfg.c
index 551b7dbd8fe7..57efe50e0d19 100644
--- a/drivers/platform/x86/asus-bioscfg.c
+++ b/drivers/platform/x86/asus-bioscfg.c
@@ -426,6 +426,120 @@ static ssize_t egpu_enable_current_value_store(struct kobject *kobj,
 WMI_SHOW_INT(egpu_enable_current_value, "%d\n", ASUS_WMI_DEVID_EGPU);
 ATTR_GROUP_BOOL_CUSTOM(egpu_enable, "egpu_enable", "Enable the eGPU (also disables dGPU)");
 
+/* Device memory available to APU */
+
+static ssize_t apu_mem_current_value_show(struct kobject *kobj,
+				struct kobj_attribute *attr, char *buf)
+{
+	int err;
+	u32 mem;
+
+	err = asus_wmi_get_devstate_dsts(ASUS_WMI_DEVID_APU_MEM, &mem);
+	if (err)
+		return err;
+
+	switch (mem) {
+	case 256:
+		mem = 0;
+		break;
+	case 258:
+		mem = 1;
+		break;
+	case 259:
+		mem = 2;
+		break;
+	case 260:
+		mem = 3;
+		break;
+	case 261:
+		mem = 4;
+		break;
+	case 262:
+		/* This is out of order and looks wrong but is correct */
+		mem = 8;
+		break;
+	case 263:
+		mem = 5;
+		break;
+	case 264:
+		mem = 6;
+		break;
+	case 265:
+		mem = 7;
+		break;
+	default:
+		mem = 4;
+		break;
+	}
+
+	return sysfs_emit(buf, "%d\n", mem);
+}
+
+static ssize_t apu_mem_current_value_store(struct kobject *kobj,
+				struct kobj_attribute *attr,
+				const char *buf, size_t count)
+{
+	int result, err;
+	u32 requested, mem;
+
+	result = kstrtou32(buf, 10, &requested);
+	if (result)
+		return result;
+
+	switch (requested) {
+	case 0:
+		mem = 0;
+		break;
+	case 1:
+		mem = 258;
+		break;
+	case 2:
+		mem = 259;
+		break;
+	case 3:
+		mem = 260;
+		break;
+	case 4:
+		mem = 261;
+		break;
+	case 5:
+		mem = 263;
+		break;
+	case 6:
+		mem = 264;
+		break;
+	case 7:
+		mem = 265;
+		break;
+	case 8:
+		/* This is outof order and looks wrong but is correct */
+		mem = 262;
+		break;
+	default:
+		return -EIO;
+	}
+
+	err = asus_wmi_set_devstate(ASUS_WMI_DEVID_APU_MEM, mem, &result);
+	if (err) {
+		pr_warn("Failed to set apu_mem: %d\n", err);
+		return err;
+	}
+
+	pr_info("APU memory changed to %dGB, reboot required\n", requested);
+	sysfs_notify(kobj, NULL, attr->attr.name);
+
+	asus_set_reboot_and_signal_event();
+
+	return count;
+}
+
+static ssize_t apu_mem_possible_values_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "0;1;2;3;4;5;6;7;8\n");
+}
+ATTR_GROUP_ENUM_CUSTOM(apu_mem, "apu_mem", "Set the available system memory for the APU to use");
+
 /* Simple attribute creation */
 ATTR_GROUP_ENUM_INT_RW(thermal_policy, "thermal_policy", ASUS_WMI_DEVID_THROTTLE_THERMAL_POLICY,
 		0, 3, "0;1;2", "Set the thermal profile: 0=normal, 1=performance, 2=quiet");
@@ -543,6 +657,8 @@ static int asus_fw_attr_add(void)
 		sysfs_create_group(&asus_bioscfg.fw_attr_kset->kobj, &dgpu_base_tgp_attr_group);
 	if (asus_wmi_is_present(ASUS_WMI_DEVID_DGPU_SET_TGP))
 		sysfs_create_group(&asus_bioscfg.fw_attr_kset->kobj, &dgpu_tgp_attr_group);
+	if (asus_wmi_is_present(ASUS_WMI_DEVID_APU_MEM))
+		sysfs_create_group(&asus_bioscfg.fw_attr_kset->kobj, &apu_mem_attr_group);
 
 	if (asus_wmi_is_present(ASUS_WMI_DEVID_CHARGE_MODE))
 		sysfs_create_group(&asus_bioscfg.fw_attr_kset->kobj, &charge_mode_attr_group);
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index c54264653d75..e3d511918416 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -130,6 +130,7 @@
 
 #define ASUS_WMI_DEVID_DGPU_BASE_TGP	0x00120099
 #define ASUS_WMI_DEVID_DGPU_SET_TGP	0x00120098
+#define ASUS_WMI_DEVID_APU_MEM		0x000600C1
 
 /* gpu mux switch, 0 = dGPU, 1 = Optimus */
 #define ASUS_WMI_DEVID_GPU_MUX		0x00090016
-- 
2.45.2