ALSA: line6: Use container_of()

... instead of unconditional cast.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/line6/pod.c

@@ -74,6 +74,8 @@ struct usb_line6_pod {
 	int device_id;
 };
 
+#define line6_to_pod(x)		container_of(x, struct usb_line6_pod, line6)
+
 #define POD_SYSEX_CODE 3
 
 /* *INDENT-OFF* */
@@ -177,7 +179,7 @@ static char *pod_alloc_sysex_buffer(struct usb_line6_pod *pod, int code,
 */
 static void line6_pod_process_message(struct usb_line6 *line6)
 {
-	struct usb_line6_pod *pod = (struct usb_line6_pod *) line6;
+	struct usb_line6_pod *pod = line6_to_pod(line6);
 	const unsigned char *buf = pod->line6.buffer_message;
 
 	if (memcmp(buf, pod_version_header, sizeof(pod_version_header)) == 0) {
@@ -274,7 +276,7 @@ static ssize_t device_id_show(struct device *dev,
 
 static void pod_startup(struct usb_line6 *line6)
 {
-	struct usb_line6_pod *pod = (struct usb_line6_pod *) line6;
+	struct usb_line6_pod *pod = line6_to_pod(line6);
 
 	switch (pod->startup_progress) {
 	case POD_STARTUP_VERSIONREQ:
@@ -328,7 +330,7 @@ static int snd_pod_control_monitor_get(struct snd_kcontrol *kcontrol,
 				       struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
-	struct usb_line6_pod *pod = (struct usb_line6_pod *)line6pcm->line6;
+	struct usb_line6_pod *pod = line6_to_pod(line6pcm->line6);
 
 	ucontrol->value.integer.value[0] = pod->monitor_level;
 	return 0;
@@ -339,7 +341,7 @@ static int snd_pod_control_monitor_put(struct snd_kcontrol *kcontrol,
 				       struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
-	struct usb_line6_pod *pod = (struct usb_line6_pod *)line6pcm->line6;
+	struct usb_line6_pod *pod = line6_to_pod(line6pcm->line6);
 
 	if (ucontrol->value.integer.value[0] == pod->monitor_level)
 		return 0;
@@ -368,7 +370,7 @@ static int pod_init(struct usb_line6 *line6,
 		    const struct usb_device_id *id)
 {
 	int err;
-	struct usb_line6_pod *pod = (struct usb_line6_pod *) line6;
+	struct usb_line6_pod *pod = line6_to_pod(line6);
 
 	line6->process_message = line6_pod_process_message;
 	line6->startup = pod_startup;

sound/usb/line6/podhd.c

@@ -44,6 +44,8 @@ struct usb_line6_podhd {
 	int firmware_version;
 };
 
+#define line6_to_podhd(x)	container_of(x, struct usb_line6_podhd, line6)
+
 static struct snd_ratden podhd_ratden = {
 	.num_min = 48000,
 	.num_max = 48000,
@@ -231,7 +233,7 @@ static int podhd_dev_start(struct usb_line6_podhd *pod)
 
 static void podhd_startup(struct usb_line6 *line6)
 {
-	struct usb_line6_podhd *pod = (struct usb_line6_podhd *)line6;
+	struct usb_line6_podhd *pod = line6_to_podhd(line6);
 
 	podhd_dev_start(pod);
 	line6_read_serial_number(&pod->line6, &pod->serial_number);
@@ -241,7 +243,7 @@ static void podhd_startup(struct usb_line6 *line6)
 
 static void podhd_disconnect(struct usb_line6 *line6)
 {
-	struct usb_line6_podhd *pod = (struct usb_line6_podhd *)line6;
+	struct usb_line6_podhd *pod = line6_to_podhd(line6);
 
 	if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL_INFO) {
 		struct usb_interface *intf;
@@ -260,7 +262,7 @@ static int podhd_init(struct usb_line6 *line6,
 		      const struct usb_device_id *id)
 {
 	int err;
-	struct usb_line6_podhd *pod = (struct usb_line6_podhd *) line6;
+	struct usb_line6_podhd *pod = line6_to_podhd(line6);
 	struct usb_interface *intf;
 
 	line6->disconnect = podhd_disconnect;

sound/usb/line6/toneport.c

@@ -61,6 +61,8 @@ struct usb_line6_toneport {
 	struct toneport_led leds[2];
 };
 
+#define line6_to_toneport(x) container_of(x, struct usb_line6_toneport, line6)
+
 static int toneport_send_cmd(struct usb_device *usbdev, int cmd1, int cmd2);
 
 #define TONEPORT_PCM_DELAY 1
@@ -211,8 +213,8 @@ static int snd_toneport_source_get(struct snd_kcontrol *kcontrol,
 				   struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
-	struct usb_line6_toneport *toneport =
-	    (struct usb_line6_toneport *)line6pcm->line6;
+	struct usb_line6_toneport *toneport = line6_to_toneport(line6pcm->line6);
+
 	ucontrol->value.enumerated.item[0] = toneport->source;
 	return 0;
 }
@@ -222,8 +224,7 @@ static int snd_toneport_source_put(struct snd_kcontrol *kcontrol,
 				   struct snd_ctl_elem_value *ucontrol)
 {
 	struct snd_line6_pcm *line6pcm = snd_kcontrol_chip(kcontrol);
-	struct usb_line6_toneport *toneport =
-	    (struct usb_line6_toneport *)line6pcm->line6;
+	struct usb_line6_toneport *toneport = line6_to_toneport(line6pcm->line6);
 	unsigned int source;
 
 	source = ucontrol->value.enumerated.item[0];
@@ -397,8 +398,7 @@ static int toneport_setup(struct usb_line6_toneport *toneport)
 */
 static void line6_toneport_disconnect(struct usb_line6 *line6)
 {
-	struct usb_line6_toneport *toneport =
-		(struct usb_line6_toneport *)line6;
+	struct usb_line6_toneport *toneport = line6_to_toneport(line6);
 
 	if (toneport_has_led(toneport))
 		toneport_remove_leds(toneport);
@@ -412,7 +412,7 @@ static int toneport_init(struct usb_line6 *line6,
 			 const struct usb_device_id *id)
 {
 	int err;
-	struct usb_line6_toneport *toneport =  (struct usb_line6_toneport *) line6;
+	struct usb_line6_toneport *toneport = line6_to_toneport(line6);
 
 	toneport->type = id->driver_info;
 

sound/usb/line6/variax.c

@@ -47,6 +47,8 @@ struct usb_line6_variax {
 	int startup_progress;
 };
 
+#define line6_to_variax(x)	container_of(x, struct usb_line6_variax, line6)
+
 #define VARIAX_OFFSET_ACTIVATE 7
 
 /*
@@ -86,7 +88,7 @@ static void variax_activate_async(struct usb_line6_variax *variax, int a)
 
 static void variax_startup(struct usb_line6 *line6)
 {
-	struct usb_line6_variax *variax = (struct usb_line6_variax *)line6;
+	struct usb_line6_variax *variax = line6_to_variax(line6);
 
 	switch (variax->startup_progress) {
 	case VARIAX_STARTUP_VERSIONREQ:
@@ -115,7 +117,7 @@ static void variax_startup(struct usb_line6 *line6)
 */
 static void line6_variax_process_message(struct usb_line6 *line6)
 {
-	struct usb_line6_variax *variax = (struct usb_line6_variax *) line6;
+	struct usb_line6_variax *variax = line6_to_variax(line6);
 	const unsigned char *buf = variax->line6.buffer_message;
 
 	switch (buf[0]) {
@@ -149,7 +151,7 @@ static void line6_variax_process_message(struct usb_line6 *line6)
 */
 static void line6_variax_disconnect(struct usb_line6 *line6)
 {
-	struct usb_line6_variax *variax = (struct usb_line6_variax *)line6;
+	struct usb_line6_variax *variax = line6_to_variax(line6);
 
 	kfree(variax->buffer_activate);
 }
@@ -160,7 +162,7 @@ static void line6_variax_disconnect(struct usb_line6 *line6)
 static int variax_init(struct usb_line6 *line6,
 		       const struct usb_device_id *id)
 {
-	struct usb_line6_variax *variax = (struct usb_line6_variax *) line6;
+	struct usb_line6_variax *variax = line6_to_variax(line6);
 	int err;
 
 	line6->process_message = line6_variax_process_message;