V4L/DVB (7893): xc5000: bug-fix: allow multiple devices in a single system

The current code passes a context pointer in the xc5000_config struct.
This context pointer is used in the tuner_callback function, used to
reset the device after firmware download.

The xc5000_config struct is a static structure, whose .priv member was
being assigned before calling xc5000_attach(). If there are more than
one of the same device type installed on a single system, the last one
to assign xc5000_config.priv will "win", and all others will cease to
function properly.

This patch passes the context pointer in xc5000_attach() rather that
storing it within the static struct xc5000_config.

Signed-off-by: Michael Krufky <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/common/tuners/xc5000.c

···
 	dprintk(1, "%s()\n", __func__);
 
 	if (priv->cfg->tuner_callback) {
-		ret = priv->cfg->tuner_callback(priv->cfg->priv,
+		ret = priv->cfg->tuner_callback(priv->devptr,
 						XC5000_TUNER_RESET, 0);
 		if (ret)
 			printk(KERN_ERR "xc5000: reset failed\n");
···
 	.get_status	   = xc5000_get_status
 };
 
-struct dvb_frontend * xc5000_attach(struct dvb_frontend *fe,
-	struct i2c_adapter *i2c,
-	struct xc5000_config *cfg)
+struct dvb_frontend *xc5000_attach(struct dvb_frontend *fe,
+				   struct i2c_adapter *i2c,
+				   struct xc5000_config *cfg, void *devptr)
 {
 	struct xc5000_priv *priv = NULL;
 	u16 id = 0;
···
 	priv->cfg = cfg;
 	priv->bandwidth = BANDWIDTH_6_MHZ;
 	priv->i2c = i2c;
+	priv->devptr = devptr;
 
 	/* Check if firmware has been loaded. It is possible that another
 	   instance of the driver has loaded the firmware.

drivers/media/common/tuners/xc5000.h

···
 	u8   i2c_address;
 	u32  if_khz;
 
-	/* For each bridge framework, when it attaches either analog or digital,
-	 * it has to store a reference back to its _core equivalent structure,
-	 * so that it can service the hardware by steering gpio's etc.
-	 * Each bridge implementation is different so cast priv accordingly.
-	 * The xc5000 driver cares not for this value, other than ensuring
-	 * it's passed back to a bridge during tuner_callback().
-	 */
-	void *priv;
 	int  (*tuner_callback) (void *priv, int command, int arg);
 };
 
 /* xc5000 callback command */
 #define XC5000_TUNER_RESET		0
 
+/* For each bridge framework, when it attaches either analog or digital,
+ * it has to store a reference back to its _core equivalent structure,
+ * so that it can service the hardware by steering gpio's etc.
+ * Each bridge implementation is different so cast devptr accordingly.
+ * The xc5000 driver cares not for this value, other than ensuring
+ * it's passed back to a bridge during tuner_callback().
+ */
+
 #if defined(CONFIG_MEDIA_TUNER_XC5000) || \
     (defined(CONFIG_MEDIA_TUNER_XC5000_MODULE) && defined(MODULE))
 extern struct dvb_frontend* xc5000_attach(struct dvb_frontend *fe,
 					  struct i2c_adapter *i2c,
-					  struct xc5000_config *cfg);
+					  struct xc5000_config *cfg,
+					  void *devptr);
 #else
 static inline struct dvb_frontend* xc5000_attach(struct dvb_frontend *fe,
 						 struct i2c_adapter *i2c,
-						 struct xc5000_config *cfg)
+						 struct xc5000_config *cfg,
+						 void *devptr)
 {
 	printk(KERN_WARNING "%s: driver disabled by Kconfig\n", __func__);
 	return NULL;

drivers/media/common/tuners/xc5000_priv.h

···
 	u8  video_standard;
 	u8  rf_mode;
 	u8  fwloaded;
+
+	void *devptr;
 };
 
 #endif

drivers/media/video/au0828/au0828-dvb.c

···
 		dvb->frontend = dvb_attach(au8522_attach,
 				&hauppauge_hvr950q_config,
 				&dev->i2c_adap);
-		if (dvb->frontend != NULL) {
-			hauppauge_hvr950q_tunerconfig.priv = dev;
+		if (dvb->frontend != NULL)
 			dvb_attach(xc5000_attach, dvb->frontend,
 				&dev->i2c_adap,
-				&hauppauge_hvr950q_tunerconfig);
-		}
+				&hauppauge_hvr950q_tunerconfig, dev);
 		break;
 	default:
 		printk(KERN_WARNING "The frontend of your DVB/ATSC card "

drivers/media/video/cx23885/cx23885-dvb.c

···
 		port->dvb.frontend = dvb_attach(s5h1409_attach,
 						&hauppauge_hvr1500q_config,
 						&dev->i2c_bus[0].i2c_adap);
-		if (port->dvb.frontend != NULL) {
-			hauppauge_hvr1500q_tunerconfig.priv = i2c_bus;
+		if (port->dvb.frontend != NULL)
 			dvb_attach(xc5000_attach, port->dvb.frontend,
 				&i2c_bus->i2c_adap,
-				&hauppauge_hvr1500q_tunerconfig);
-		}
+				&hauppauge_hvr1500q_tunerconfig, i2c_bus);
 		break;
 	case CX23885_BOARD_HAUPPAUGE_HVR1500:
 		i2c_bus = &dev->i2c_bus[1];

drivers/media/video/cx88/cx88-dvb.c

···
 			/* tuner_config.video_dev must point to
 			 * i2c_adap.algo_data
 			 */
-			pinnacle_pctv_hd_800i_tuner_config.priv =
-						core->i2c_adap.algo_data;
 			if (!dvb_attach(xc5000_attach, dev->dvb.frontend,
 					&core->i2c_adap,
-					&pinnacle_pctv_hd_800i_tuner_config))
+					&pinnacle_pctv_hd_800i_tuner_config,
+					core->i2c_adap.algo_data))
 				goto frontend_detach;
 		}
 		break;
···
 			/* tuner_config.video_dev must point to
 			 * i2c_adap.algo_data
 			 */
-			dvico_fusionhdtv7_tuner_config.priv =
-						core->i2c_adap.algo_data;
 			if (!dvb_attach(xc5000_attach, dev->dvb.frontend,
 					&core->i2c_adap,
-					&dvico_fusionhdtv7_tuner_config))
+					&dvico_fusionhdtv7_tuner_config,
+					core->i2c_adap.algo_data))
 				goto frontend_detach;
 		}
 		break;

drivers/media/video/tuner-core.c

···
 
 		xc5000_cfg.i2c_address	  = t->i2c->addr;
 		xc5000_cfg.if_khz	  = 5380;
-		xc5000_cfg.priv           = c->adapter->algo_data;
 		xc5000_cfg.tuner_callback = t->tuner_callback;
 		if (!dvb_attach(xc5000_attach,
-				&t->fe, t->i2c->adapter, &xc5000_cfg))
+				&t->fe, t->i2c->adapter, &xc5000_cfg,
+				c->adapter->algo_data))
 			goto attach_failed;
 
 		xc_tuner_ops = &t->fe.ops.tuner_ops;