[PATCH v4 7/9] platform/x86: asus-armoury: add apu-mem control support

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

Implement the APU memory size control under the asus-armoury 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-armoury.c        | 114 +++++++++++++++++++++
 include/linux/platform_data/x86/asus-wmi.h |   1 +
 2 files changed, 115 insertions(+)

diff --git a/drivers/platform/x86/asus-armoury.c b/drivers/platform/x86/asus-armoury.c
index 0f67b5deb629..a0022dcee3a4 100644
--- a/drivers/platform/x86/asus-armoury.c
+++ b/drivers/platform/x86/asus-armoury.c
@@ -456,6 +456,119 @@ static ssize_t egpu_enable_current_value_store(struct kobject *kobj, struct 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 0x100:
+		mem = 0;
+		break;
+	case 0x102:
+		mem = 1;
+		break;
+	case 0x103:
+		mem = 2;
+		break;
+	case 0x104:
+		mem = 3;
+		break;
+	case 0x105:
+		mem = 4;
+		break;
+	case 0x106:
+		/* This is out of order and looks wrong but is correct */
+		mem = 8;
+		break;
+	case 0x107:
+		mem = 5;
+		break;
+	case 0x108:
+		mem = 6;
+		break;
+	case 0x109:
+		mem = 7;
+		break;
+	default:
+		mem = 4;
+		break;
+	}
+
+	return sysfs_emit(buf, "%u\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 = 0x000;
+		break;
+	case 1:
+		mem = 0x102;
+		break;
+	case 2:
+		mem = 0x103;
+		break;
+	case 3:
+		mem = 0x104;
+		break;
+	case 4:
+		mem = 0x105;
+		break;
+	case 5:
+		mem = 0x107;
+		break;
+	case 6:
+		mem = 0x108;
+		break;
+	case 7:
+		mem = 0x109;
+		break;
+	case 8:
+		/* This is out of order and looks wrong but is correct */
+		mem = 0x106;
+		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 %uGB, 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 available system RAM (in GB) for the APU to use");
+
 /* Simple attribute creation */
 ATTR_GROUP_ROG_TUNABLE(ppt_pl1_spl, "ppt_pl1_spl", ASUS_WMI_DEVID_PPT_PL1_SPL, cpu_default,
 		       cpu_min, cpu_max, 1, "Set the CPU slow package limit");
@@ -511,6 +624,7 @@ static const struct asus_attr_group armoury_attr_groups[] = {
 	{ &nv_temp_target_attr_group, ASUS_WMI_DEVID_NV_THERM_TARGET },
 	{ &dgpu_base_tgp_attr_group, ASUS_WMI_DEVID_DGPU_BASE_TGP },
 	{ &dgpu_tgp_attr_group, ASUS_WMI_DEVID_DGPU_SET_TGP },
+	{ &apu_mem_attr_group, ASUS_WMI_DEVID_APU_MEM },
 
 	{ &charge_mode_attr_group, ASUS_WMI_DEVID_CHARGE_MODE },
 	{ &boot_sound_attr_group, ASUS_WMI_DEVID_BOOT_SOUND },
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index 86629e621c61..e1aeafdf05d5 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -136,6 +136,7 @@
 
 #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
-- 
2.46.1