V4L/DVB (7346): tda9887: allow multiple driver instances for the same hardware to share state

Convert tda9887 to use the new hybrid_tuner_request_state and
hybrid_tuner_release_state macros to manage state sharing between
hybrid tuner instances.

Some ATSC/DVB cards need to put the analog demodulator into standby
before tuning digital.  This patch allows us to attach the tda9887
driver to the digital side of the bridge driver and be able to put
it into standby without jeopardizing the analog demod driver's state.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/tda9887.c

@@ -25,8 +25,12 @@ static int debug;
 module_param(debug, int, 0644);
 MODULE_PARM_DESC(debug, "enable verbose debug messages");
 
+static DEFINE_MUTEX(tda9887_list_mutex);
+static LIST_HEAD(hybrid_tuner_instance_list);
+
 struct tda9887_priv {
 	struct tuner_i2c_props i2c_props;
+	struct list_head hybrid_tuner_instance_list;
 
 	unsigned char 	   data[4];
 	unsigned int       config;
@@ -642,7 +646,15 @@ static int tda9887_set_config(struct dvb_frontend *fe, void *priv_cfg)
 
 static void tda9887_release(struct dvb_frontend *fe)
 {
-	kfree(fe->analog_demod_priv);
+	struct tda9887_priv *priv = fe->analog_demod_priv;
+
+	mutex_lock(&tda9887_list_mutex);
+
+	if (priv)
+		hybrid_tuner_release_state(priv);
+
+	mutex_unlock(&tda9887_list_mutex);
+
 	fe->analog_demod_priv = NULL;
 }
 
@@ -663,18 +675,29 @@ struct dvb_frontend *tda9887_attach(struct dvb_frontend *fe,
 				    u8 i2c_addr)
 {
 	struct tda9887_priv *priv = NULL;
+	int instance;
 
-	priv = kzalloc(sizeof(struct tda9887_priv), GFP_KERNEL);
-	if (priv == NULL)
-		return NULL;
-	fe->analog_demod_priv = priv;
+	mutex_lock(&tda9887_list_mutex);
 
-	priv->i2c_props.addr = i2c_addr;
-	priv->i2c_props.adap = i2c_adap;
-	priv->i2c_props.name = "tda9887";
-	priv->mode = T_STANDBY;
+	instance = hybrid_tuner_request_state(struct tda9887_priv, priv,
+					      hybrid_tuner_instance_list,
+					      i2c_adap, i2c_addr, "tda9887");
+	switch (instance) {
+	case 0:
+		mutex_unlock(&tda9887_list_mutex);
+		return NULL;
+		break;
+	case 1:
+		fe->analog_demod_priv = priv;
+		priv->mode = T_STANDBY;
+		tuner_info("tda988[5/6/7] found\n");
+		break;
+	default:
+		fe->analog_demod_priv = priv;
+		break;
+	}
 
-	tuner_info("tda988[5/6/7] found\n");
+	mutex_unlock(&tda9887_list_mutex);
 
 	memcpy(&fe->ops.analog_ops, &tda9887_ops,
 	       sizeof(struct analog_demod_ops));