lib: enable standby mode of e4k and r820t on exit

Since the R820T is a power hog and gets quite hot,
this makes sense, especially when being battery-
powered.

Signed-off-by: Steve Markgraf <steve@steve-m.de>

include/tuner_e4k.h

@@ -199,6 +199,7 @@ struct e4k_state {
 };
 
 int e4k_init(struct e4k_state *e4k);
+int e4k_standby(struct e4k_state *e4k, int enable);
 int e4k_if_gain_set(struct e4k_state *e4k, uint8_t stage, int8_t value);
 int e4k_mixer_gain_set(struct e4k_state *e4k, int8_t value);
 int e4k_commonmode_set(struct e4k_state *e4k, int8_t value);

src/librtlsdr.c

@@ -101,7 +101,10 @@ int e4000_init(void *dev) {
 	devt->e4k_s.rtl_dev = dev;
 	return e4k_init(&devt->e4k_s);
 }
-int e4000_exit(void *dev) { return 0; }
+int e4000_exit(void *dev) {
+	rtlsdr_dev_t* devt = (rtlsdr_dev_t*)dev;
+	return e4k_standby(&devt->e4k_s, 1);
+}
 int e4000_set_freq(void *dev, uint32_t freq) {
 	rtlsdr_dev_t* devt = (rtlsdr_dev_t*)dev;
 	return e4k_tune_freq(&devt->e4k_s, freq);
@@ -177,7 +180,7 @@ int r820t_init(void *dev) {
 	r820t_SetStandardMode(dev, DVB_T_6M);
 	return r;
 }
-int r820t_exit(void *dev) { return 0; }
+int r820t_exit(void *dev) { return r820t_SetStandby(dev, 0); }
 int r820t_set_freq(void *dev, uint32_t freq) { return r820t_SetRfFreqHz(dev, freq); }
 int r820t_set_bw(void *dev, int bw) { return 0; }
 int r820t_set_gain(void *dev, int gain) { return R828_SetRfGain(dev, gain); }
@@ -360,7 +363,8 @@ uint8_t rtlsdr_i2c_read_reg(rtlsdr_dev_t *dev, uint8_t i2c_addr, uint8_t reg)
 /* TODO clean this up again */
 int e4k_reg_write(struct e4k_state *e4k, uint8_t reg, uint8_t val)
 {
-	return rtlsdr_i2c_write_reg((rtlsdr_dev_t*)e4k->rtl_dev, e4k->i2c_addr, reg, val);}
+	return rtlsdr_i2c_write_reg((rtlsdr_dev_t*)e4k->rtl_dev, e4k->i2c_addr, reg, val);
+}
 
 uint8_t e4k_reg_read(struct e4k_state *e4k, uint8_t reg)
 {

src/tuner_e4k.c

@@ -881,6 +881,19 @@ int e4k_dc_offset_gen_table(struct e4k_state *e4k)
 }
 
 /***********************************************************************
+ * Standby */
+
+/*! \brief Enable/disable standby mode
+ */
+int e4k_standby(struct e4k_state *e4k, int enable)
+{
+	e4k_reg_set_mask(e4k, E4K_REG_MASTER1, E4K_MASTER1_NORM_STBY,
+			 enable ? 0 : E4K_MASTER1_NORM_STBY);
+
+	return 0;
+}
+
+/***********************************************************************
  * Initialization */
 
 static int magic_init(struct e4k_state *e4k)

src/tuner_r820t.c

@@ -2896,7 +2896,7 @@ R828_ErrCode R828_Standby(void *pTuner, R828_LoopThrough_Type R828_LoopSwitch)
 		return RT_Fail;
 
 	R828_I2C.RegAddr = 0x0F;
-	R828_I2C.Data    = 0x78;
+	R828_I2C.Data    = 0x68; /* was 0x78, which turns off CLK_Out */
 	if(I2C_Write(pTuner, &R828_I2C) != RT_Success)
 		return RT_Fail;