V4L/DVB (7383): tda18271: add attach-time parameter to limit i2c transfer size

Add attach-time parameter, "small_i2c" to limit i2c transfer size to write
at most 16 registers at a time during initialization.
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/dvb/frontends/tda18271-common.c

@@ -311,7 +311,12 @@ int tda18271_init_regs(struct dvb_frontend *fe)
 	regs[R_EB22] = 0x48;
 	regs[R_EB23] = 0xb0;
 
-	tda18271_write_regs(fe, 0x00, TDA18271_NUM_REGS);
+	if (priv->small_i2c) {
+		tda18271_write_regs(fe, 0x00, 0x10);
+		tda18271_write_regs(fe, 0x10, 0x10);
+		tda18271_write_regs(fe, 0x20, 0x07);
+	} else
+		tda18271_write_regs(fe, 0x00, TDA18271_NUM_REGS);
 
 	/* setup agc1 gain */
 	regs[R_EB17] = 0x00;

drivers/media/dvb/frontends/tda18271-fe.c

@@ -1081,6 +1081,9 @@ struct dvb_frontend *tda18271_attach(struct dvb_frontend *fe, u8 addr,
 
 		fe->tuner_priv = priv;
 
+		if (cfg)
+			priv->small_i2c = cfg->small_i2c;
+
 		if (tda18271_get_id(fe) < 0)
 			goto fail;
 

drivers/media/dvb/frontends/tda18271-priv.h

@@ -110,6 +110,7 @@ struct tda18271_priv {
 
 	unsigned int tm_rfcal;
 	unsigned int cal_initialized:1;
+	unsigned int small_i2c:1;
 
 	struct tda18271_map_layout *maps;
 	struct tda18271_std_map std;

drivers/media/dvb/frontends/tda18271.h

@@ -58,6 +58,9 @@ struct tda18271_config {
 
 	/* use i2c gate provided by analog or digital demod */
 	enum tda18271_i2c_gate gate;
+
+	/* some i2c providers cant write all 39 registers at once */
+	unsigned int small_i2c:1;
 };
 
 #if defined(CONFIG_DVB_TDA18271) || (defined(CONFIG_DVB_TDA18271_MODULE) && defined(MODULE))