platform/x86: thinkpad_acpi: Make *_init() functions return -ENODEV instead of 1

Make ibm_init_struct.init() callbacks return -ENODEV instead of 1 when
the subdevice / function is not available.

Using -ENODEV clearly states what it going on where as a magic return of
"1" requires a deep dive into the code to figure out what is going on.

This also allows for some cleanups, avoiding the need to translate an
-ENODEV return into "return 1" (which often mistakenly was "return 0").
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Mark Pearson <mpearson@lenovo.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211121191129.256713-3-hdegoede@redhat.com

drivers/platform/x86/thinkpad_acpi.c

@@ -3377,7 +3377,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 		str_supported(tp_features.hotkey));
 
 	if (!tp_features.hotkey)
-		return 1;
+		return -ENODEV;
 
 	quirks = tpacpi_check_quirks(tpacpi_hotkey_qtable,
 				     ARRAY_SIZE(tpacpi_hotkey_qtable));
@@ -3584,7 +3584,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
 	return 0;
 
 err_exit:
-	return (res < 0) ? res : 1;
+	return (res < 0) ? res : -ENODEV;
 }
 
 /* Thinkpad X1 Carbon support 5 modes including Home mode, Web browser
@@ -4451,7 +4451,7 @@ static int __init bluetooth_init(struct ibm_init_struct *iibm)
 	}
 
 	if (!tp_features.bluetooth)
-		return 1;
+		return -ENODEV;
 
 	res = tpacpi_new_rfkill(TPACPI_RFK_BLUETOOTH_SW_ID,
 				&bluetooth_tprfk_ops,
@@ -4631,7 +4631,7 @@ static int __init wan_init(struct ibm_init_struct *iibm)
 	}
 
 	if (!tp_features.wan)
-		return 1;
+		return -ENODEV;
 
 	res = tpacpi_new_rfkill(TPACPI_RFK_WWAN_SW_ID,
 				&wan_tprfk_ops,
@@ -4760,7 +4760,7 @@ static int __init uwb_init(struct ibm_init_struct *iibm)
 	}
 
 	if (!tp_features.uwb)
-		return 1;
+		return -ENODEV;
 
 	res = tpacpi_new_rfkill(TPACPI_RFK_UWB_SW_ID,
 				&uwb_tprfk_ops,
@@ -4853,7 +4853,7 @@ static int __init video_init(struct ibm_init_struct *iibm)
 		str_supported(video_supported != TPACPI_VIDEO_NONE),
 		video_supported);
 
-	return (video_supported != TPACPI_VIDEO_NONE) ? 0 : 1;
+	return (video_supported != TPACPI_VIDEO_NONE) ? 0 : -ENODEV;
 }
 
 static void video_exit(void)
@@ -5261,7 +5261,7 @@ static int __init kbdlight_init(struct ibm_init_struct *iibm)
 	if (!kbdlight_is_supported()) {
 		tp_features.kbdlight = 0;
 		vdbg_printk(TPACPI_DBG_INIT, "kbdlight is unsupported\n");
-		return 1;
+		return -ENODEV;
 	}
 
 	kbdlight_brightness = kbdlight_sysfs_get(NULL);
@@ -5451,7 +5451,7 @@ static int __init light_init(struct ibm_init_struct *iibm)
 		str_supported(tp_features.light_status));
 
 	if (!tp_features.light)
-		return 1;
+		return -ENODEV;
 
 	rc = led_classdev_register(&tpacpi_pdev->dev,
 				   &tpacpi_led_thinklight.led_classdev);
@@ -5567,7 +5567,7 @@ static int __init cmos_init(struct ibm_init_struct *iibm)
 	vdbg_printk(TPACPI_DBG_INIT, "cmos commands are %s\n",
 		    str_supported(cmos_handle != NULL));
 
-	return cmos_handle ? 0 : 1;
+	return cmos_handle ? 0 : -ENODEV;
 }
 
 static int cmos_read(struct seq_file *m)
@@ -5912,7 +5912,7 @@ static int __init led_init(struct ibm_init_struct *iibm)
 		str_supported(led_supported), led_supported);
 
 	if (led_supported == TPACPI_LED_NONE)
-		return 1;
+		return -ENODEV;
 
 	tpacpi_leds = kcalloc(TPACPI_LED_NUMLEDS, sizeof(*tpacpi_leds),
 			      GFP_KERNEL);
@@ -6041,7 +6041,7 @@ static int __init beep_init(struct ibm_init_struct *iibm)
 
 	tp_features.beep_needs_two_args = !!(quirks & TPACPI_BEEP_Q1);
 
-	return (beep_handle) ? 0 : 1;
+	return (beep_handle) ? 0 : -ENODEV;
 }
 
 static int beep_read(struct seq_file *m)
@@ -6425,7 +6425,7 @@ static int __init thermal_init(struct ibm_init_struct *iibm)
 		str_supported(thermal_read_mode != TPACPI_THERMAL_NONE),
 		thermal_read_mode);
 
-	return thermal_read_mode == TPACPI_THERMAL_NONE ? 1 : 0;
+	return thermal_read_mode != TPACPI_THERMAL_NONE ? 0 : -ENODEV;
 }
 
 static int thermal_read(struct seq_file *m)
@@ -6836,25 +6836,25 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 
 	/* if it is unknown, we don't handle it: it wouldn't be safe */
 	if (tp_features.bright_unkfw)
-		return 1;
+		return -ENODEV;
 
 	if (!brightness_enable) {
 		dbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_BRGHT,
 			   "brightness support disabled by module parameter\n");
-		return 1;
+		return -ENODEV;
 	}
 
 	if (acpi_video_get_backlight_type() != acpi_backlight_vendor) {
 		if (brightness_enable > 1) {
 			pr_info("Standard ACPI backlight interface available, not loading native one\n");
-			return 1;
+			return -ENODEV;
 		} else if (brightness_enable == 1) {
 			pr_warn("Cannot enable backlight brightness support, ACPI is already handling it.  Refer to the acpi_backlight kernel parameter.\n");
-			return 1;
+			return -ENODEV;
 		}
 	} else if (!tp_features.bright_acpimode) {
 		pr_notice("ACPI backlight interface not available\n");
-		return 1;
+		return -ENODEV;
 	}
 
 	pr_notice("ACPI native brightness control enabled\n");
@@ -6887,7 +6887,7 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 		return -EINVAL;
 
 	if (tpacpi_brightness_get_raw(&b) < 0)
-		return 1;
+		return -ENODEV;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_PLATFORM;
@@ -7477,7 +7477,7 @@ static int __init volume_create_alsa_mixer(void)
 			  sizeof(struct tpacpi_alsa_data), &card);
 	if (rc < 0 || !card) {
 		pr_err("Failed to create ALSA card structures: %d\n", rc);
-		return 1;
+		return -ENODEV;
 	}
 
 	BUG_ON(!card->private_data);
@@ -7536,7 +7536,7 @@ static int __init volume_create_alsa_mixer(void)
 
 err_exit:
 	snd_card_free(card);
-	return 1;
+	return -ENODEV;
 }
 
 #define TPACPI_VOL_Q_MUTEONLY	0x0001	/* Mute-only control available */
@@ -7585,7 +7585,7 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 	if (volume_mode == TPACPI_VOL_MODE_UCMS_STEP) {
 		pr_err("UCMS step volume mode not implemented, please contact %s\n",
 		       TPACPI_MAIL);
-		return 1;
+		return -ENODEV;
 	}
 
 	if (volume_capabilities >= TPACPI_VOL_CAP_MAX)
@@ -7598,7 +7598,7 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 	if (!alsa_enable) {
 		vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_MIXER,
 			    "ALSA mixer disabled by parameter, not loading volume subdriver...\n");
-		return 1;
+		return -ENODEV;
 	}
 
 	quirks = tpacpi_check_quirks(volume_quirk_table,
@@ -7611,7 +7611,7 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 		else if (quirks & TPACPI_VOL_Q_LEVEL)
 			tp_features.mixer_no_level_control = 0;
 		else
-			return 1; /* no mixer */
+			return -ENODEV; /* no mixer */
 		break;
 	case TPACPI_VOL_CAP_VOLMUTE:
 		tp_features.mixer_no_level_control = 0;
@@ -7620,7 +7620,7 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 		tp_features.mixer_no_level_control = 1;
 		break;
 	default:
-		return 1;
+		return -ENODEV;
 	}
 
 	if (volume_capabilities != TPACPI_VOL_CAP_AUTO)
@@ -7792,7 +7792,7 @@ static int __init volume_init(struct ibm_init_struct *iibm)
 {
 	pr_info("volume: disabled as there is no ALSA support in this kernel\n");
 
-	return 1;
+	return -ENODEV;
 }
 
 static struct ibm_struct volume_driver_data = {
@@ -8729,7 +8729,7 @@ static int __init fan_init(struct ibm_init_struct *iibm)
 			}
 		} else {
 			pr_err("ThinkPad ACPI EC access misbehaving, fan status and control unavailable\n");
-			return 1;
+			return -ENODEV;
 		}
 	}
 
@@ -8778,11 +8778,11 @@ static int __init fan_init(struct ibm_init_struct *iibm)
 	if (fan_status_access_mode != TPACPI_FAN_NONE)
 		fan_get_status_safe(NULL);
 
-	if (fan_status_access_mode != TPACPI_FAN_NONE ||
-	    fan_control_access_mode != TPACPI_FAN_WR_NONE)
-		return 0;
+	if (fan_status_access_mode == TPACPI_FAN_NONE &&
+	    fan_control_access_mode == TPACPI_FAN_WR_NONE)
+		return -ENODEV;
 
-	return 1;
+	return 0;
 }
 
 static void fan_exit(void)
@@ -9886,12 +9886,9 @@ static int tpacpi_proxsensor_init(struct ibm_init_struct *iibm)
 
 	palm_err = palmsensor_get(&has_palmsensor, &palm_state);
 	lap_err = lapsensor_get(&has_lapsensor, &lap_state);
-	/*
-	 * If support isn't available (ENODEV) for both devices then quit, but
-	 * don't return an error.
-	 */
+	/* If support isn't available for both devices return -ENODEV */
 	if ((palm_err == -ENODEV) && (lap_err == -ENODEV))
-		return 0;
+		return -ENODEV;
 	/* Otherwise, if there was an error return it */
 	if (palm_err && (palm_err != -ENODEV))
 		return palm_err;
@@ -10127,13 +10124,6 @@ static int tpacpi_dytc_profile_init(struct ibm_init_struct *iibm)
 
 	dytc_profile_available = false;
 	err = dytc_command(DYTC_CMD_QUERY, &output);
-	/*
-	 * If support isn't available (ENODEV) then don't return an error
-	 * and don't create the sysfs group
-	 */
-	if (err == -ENODEV)
-		return 0;
-	/* For all other errors we can flag the failure */
 	if (err)
 		return err;
 
@@ -10436,16 +10426,9 @@ static const struct attribute_group dprc_attr_group = {
 
 static int tpacpi_dprc_init(struct ibm_init_struct *iibm)
 {
-	int err = get_wwan_antenna(&wwan_antennatype);
-
-	/*
-	 * If support isn't available (ENODEV) then quit, but don't
-	 * return an error.
-	 */
-	if (err == -ENODEV)
-		return 0;
+	int err;
 
-	/* If there was an error return it */
+	err = get_wwan_antenna(&wwan_antennatype);
 	if (err)
 		return err;