V4L/DVB (4385): Add dvb_attach() macro and supporting routines

Add dvb_attach() macro and supporting routines
Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Acked-by: Michael Krufky <mkrufky@linuxtv.org>
Acked-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/dvb/b2c2/flexcop-fe-tuner.c

@@ -527,7 +527,7 @@ int flexcop_frontend_init(struct flexcop_device *fc)
 	/* try the air atsc 2nd generation (nxt2002) */
 	if ((fc->fe = nxt200x_attach(&samsung_tbmv_config, &fc->i2c_adap)) != NULL) {
 		fc->dev_type          = FC_AIR_ATSC2;
-		dvb_pll_attach(fc->fe, 0x61, &fc->i2c_adap, &dvb_pll_samsung_tbmv);
+		dvb_attach(dvb_pll_attach, fc->fe, 0x61, &fc->i2c_adap, &dvb_pll_samsung_tbmv);
 		info("found the nxt2002 at i2c address: 0x%02x",samsung_tbmv_config.demod_address);
 	} else
 	/* try the air atsc 3nd generation (lgdt3303) */

drivers/media/dvb/dvb-core/dvb_frontend.c

@@ -1105,17 +1105,7 @@ int dvb_unregister_frontend(struct dvb_frontend* fe)
 	mutex_lock(&frontend_mutex);
 	dvb_unregister_device (fepriv->dvbdev);
 	dvb_frontend_stop (fe);
-	if (fe->ops.release_sec)
-		fe->ops.release_sec(fe);
-	if (fe->ops.tuner_ops.release) {
-		fe->ops.tuner_ops.release(fe);
-		if (fe->ops.i2c_gate_ctrl)
-			fe->ops.i2c_gate_ctrl(fe, 0);
-	}
-	if (fe->ops.release)
-		fe->ops.release(fe);
-	else
-		printk("dvb_frontend: Demodulator (%s) does not have a release callback!\n", fe->ops.info.name);
+
 	/* fe is invalid now */
 	kfree(fepriv);
 	mutex_unlock(&frontend_mutex);

drivers/media/dvb/dvb-core/dvbdev.h

@@ -102,4 +102,44 @@ extern int dvb_usercopy(struct inode *inode, struct file *file,
 			    int (*func)(struct inode *inode, struct file *file,
 			    unsigned int cmd, void *arg));
 
+
+/** generic DVB attach function. */
+#ifdef CONFIG_DVB_CORE_ATTACH
+#define dvb_attach(FUNCTION, ARGS...) ({ \
+	void *__r = NULL; \
+	typeof(&FUNCTION) __a = symbol_request(FUNCTION); \
+	if (__a) { \
+		__r = (void *) __a(ARGS); \
+		if (__r == NULL) \
+			symbol_put(FUNCTION); \
+	} else { \
+		printk(KERN_ERR "DVB: Unable to find symbol "#FUNCTION"()\n"); \
+	} \
+	__r; \
+})
+
+#define dvb_detach(FUNCPTR, ARGS...) ({ \
+	typeof((FUNCPTR)) __funcptrtmp = FUNCPTR; \
+	if (__funcptrtmp) { \
+		__funcptrtmp(ARGS); \
+		symbol_put_addr(__funcptrtmp); \
+	} \
+	FUNCPTR = NULL; \
+})
+
+#else
+#define dvb_attach(FUNCTION, ARGS...) ({ \
+	FUNCTION(ARGS); \
+})
+
+#define dvb_detach(FUNCPTR, ARGS...) \
+do { \
+	if (FUNCPTR) \
+		FUNCPTR(ARGS); \
+	FUNCPTR = NULL; \
+} while(0)
+
+#endif
+
+
 #endif /* #ifndef _DVBDEV_H_ */