added gpio functions to API and extended rtl_biast

* functions were provided from Marko Cebokli
at http://lea.hamradio.si/~s57uuu/mischam/rtlsdr/ports.html
* changed functions to return error/status
* added rtlsdr_set_gpio_status() - for testing

Signed-off-by: hayati ayguen <h_ayguen@web.de>

include/rtl-sdr.h

@@ -535,8 +535,10 @@ RTLSDR_API int rtlsdr_ir_query(rtlsdr_dev_t *dev, uint8_t *buf, size_t buf_len);
 
 
 /*!
- * Enable or disable (the bias tee on) GPIO PIN 0. (Works for rtl-sdr.com v3 dongles)
+ * Enable or disable (the bias tee on) GPIO PIN 0 - if not reconfigured.
- * See: http://www.rtl-sdr.com/rtl-sdr-blog-v-3-dongles-user-guide/
+ * See rtlsdr_set_opt_string() option 'T'.
+ * This works for rtl-sdr.com v3 dongles, see
+ *   http://www.rtl-sdr.com/rtl-sdr-blog-v-3-dongles-user-guide/
  * Note: rtlsdr_close() does not clear GPIO lines,
  * so it leaves the (bias tee) line enabled if a client program
  * doesn't explictly disable it.
@@ -554,12 +556,30 @@ RTLSDR_API int rtlsdr_set_bias_tee(rtlsdr_dev_t *dev, int on);
  * doesn't explictly disable it.
  *
  * \param dev the device handle given by rtlsdr_open()
- * \param gpio the gpio pin to configure as a Bias T control.
+ * \param gpio the gpio pin -- assuming this line is connected to Bias T.
+ *        gpio needs to be in 0 .. 7. BUT pin 4 is connected to Tuner RESET.
+ *        and for FC0012 is already connected/reserved pin 6 for switching V/U-HF.
  * \param on  1 for Bias T on. 0 for Bias T off.
  * \return -1 if device is not initialized. 0 otherwise.
  */
 RTLSDR_API int rtlsdr_set_bias_tee_gpio(rtlsdr_dev_t *dev, int gpio, int on);
 
+
+/* from http://lea.hamradio.si/~s57uuu/mischam/rtlsdr/ports.html
+ * added return of error/status */
+RTLSDR_API int rtlsdr_set_gpio_output(rtlsdr_dev_t *dev, uint8_t gpio);
+RTLSDR_API int rtlsdr_set_gpio_input(rtlsdr_dev_t *dev, uint8_t gpio);
+
+RTLSDR_API int rtlsdr_set_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int val);
+RTLSDR_API int rtlsdr_get_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int *val);
+
+RTLSDR_API int rtlsdr_set_gpio_byte(rtlsdr_dev_t *dev, int val);
+RTLSDR_API int rtlsdr_get_gpio_byte(rtlsdr_dev_t *dev, int *val);
+
+/* added for testing: */
+RTLSDR_API int rtlsdr_set_gpio_status(rtlsdr_dev_t *dev, int *status );
+
+
 /*!
  * Sets multiple options from a string encoded like "bw=300:agc=0:gain=27.3:dagc=0:T=1".
  * this is a helper function, that programs don't need to implement every single option

src/librtlsdr.c

@@ -266,7 +266,6 @@ struct rtlsdr_dev {
 	int dev_num;
 };
 
-static void rtlsdr_set_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int val);
 static int rtlsdr_demod_write_reg(rtlsdr_dev_t *dev, uint8_t page, uint16_t addr, uint16_t val, uint8_t len);
 static int rtlsdr_set_if_freq(rtlsdr_dev_t *dev, uint32_t freq);
 static int rtlsdr_update_ds(rtlsdr_dev_t *dev, uint32_t freq);
@@ -929,27 +928,77 @@ int rtlsdr_demod_write_reg(rtlsdr_dev_t *dev, uint8_t page, uint16_t addr, uint1
 	return (r == len) ? 0 : -1;
 }
 
-void rtlsdr_set_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int val)
+int rtlsdr_set_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int val)
 {
-	uint16_t r;
+	uint16_t r, retval;
 
 	gpio = 1 << gpio;
 	r = rtlsdr_read_reg(dev, SYSB, GPO, 1);
 	r = val ? (r | gpio) : (r & ~gpio);
-	rtlsdr_write_reg(dev, SYSB, GPO, r, 1);
+	retval = rtlsdr_write_reg(dev, SYSB, GPO, r, 1);
+	return retval;
 }
 
-void rtlsdr_set_gpio_output(rtlsdr_dev_t *dev, uint8_t gpio)
+int rtlsdr_set_gpio_output(rtlsdr_dev_t *dev, uint8_t gpio)
 {
-	int r;
+	int r, retval;
 	gpio = 1 << gpio;
 
 	r = rtlsdr_read_reg(dev, SYSB, GPD, 1);
-	rtlsdr_write_reg(dev, SYSB, GPD, r & ~gpio, 1);
+	retval = rtlsdr_write_reg(dev, SYSB, GPD, r & ~gpio, 1);
+	if (retval < 0)
+		return retval;
 	r = rtlsdr_read_reg(dev, SYSB, GPOE, 1);
-	rtlsdr_write_reg(dev, SYSB, GPOE, r | gpio, 1);
+	retval = rtlsdr_write_reg(dev, SYSB, GPOE, r | gpio, 1);
+	return retval;
 }
 
+int rtlsdr_get_gpio_bit(rtlsdr_dev_t *dev, uint8_t gpio, int *val)
+{
+	uint16_t r;
+
+	gpio = 1 << gpio;
+	r = rtlsdr_read_reg(dev, SYSB, GPI, 1);
+	*val = (r & gpio) ? 1 : 0;
+	return 0; /* no way to determine error with rtlsdr_read_reg() for now! */
+}
+
+int rtlsdr_set_gpio_input(rtlsdr_dev_t *dev, uint8_t gpio)
+{
+	int r, retval;
+	gpio = 1 << gpio;
+
+	r = rtlsdr_read_reg(dev, SYSB, GPD, 1);
+	retval = rtlsdr_write_reg(dev, SYSB, GPD, r | gpio, 1);
+	if (retval < 0)
+		return retval;
+	r = rtlsdr_read_reg(dev, SYSB, GPOE, 1);
+	retval = rtlsdr_write_reg(dev, SYSB, GPOE, r & ~gpio, 1);
+	return retval;
+}
+
+int rtlsdr_set_gpio_status(rtlsdr_dev_t *dev, int *status )
+{
+	int r;
+	r = rtlsdr_read_reg(dev, SYSB, GPD, 1);
+	*status = r;
+	return 0; /* no way to determine error with rtlsdr_read_reg() for now! */
+}
+
+
+int rtlsdr_get_gpio_byte(rtlsdr_dev_t *dev, int *val)
+{
+	*val = rtlsdr_read_reg(dev, SYSB, GPI, 1);
+	return 0; /* no way to determine error with rtlsdr_read_reg() for now! */
+}
+
+int rtlsdr_set_gpio_byte(rtlsdr_dev_t *dev, int val)
+{
+	int retval = rtlsdr_write_reg(dev, SYSB, GPO, val, 1);
+	return retval;
+}
+
+
 void rtlsdr_set_i2c_repeater(rtlsdr_dev_t *dev, int on)
 {
 	if (on)

src/rtl_biast.c

@@ -50,32 +50,51 @@ void usage(void)
 	fprintf(stderr,
 		"Usage:\trtl_biast [-options]\n"
 		"\t[-d device_index (default: 0)]\n"
-		"\t[-b bias_on (default: 0)]\n"
+		"\t[-g GPIO select (default: 0)]\n"
-		"\t[-g GPIO select (default: 0)]\n");
+		"\t[-b set write bias_on (default: 0, in output mode)]\n"
+		"\t[-r read pin (in input mode)]\n"
+		"\t[-w write pin (in output mode)]\n"
+		"\t[-s read all GPIO pins status (0 = write, 1 = read ?? )]\n"
+		"\t[-R read all GPIO pins ?? ]\n");
 	exit(1);
 }
 
 int main(int argc, char **argv)
 {
-	int i, r, opt;
+	int i, r, opt, val;
 	int dev_index = 0;
 	int dev_given = 0;
+	int write_pin_given = 0;
+	int read_pin_given = 0;
+	int read_all_given = 0;
+	int req_status = 0;
 	uint32_t bias_on = 0;
-	uint32_t gpio_pin = 0;
+	int gpio_pin = 0;
 	int device_count;
 
-	while ((opt = getopt(argc, argv, "d:b:g:h?")) != -1) {
+	while ((opt = getopt(argc, argv, "d:b:w:g:srRh?")) != -1) {
 		switch (opt) {
 		case 'd':
 			dev_index = verbose_device_search(optarg);
 			dev_given = 1;
 			break;
 		case 'b':
+		case 'w':
 			bias_on = atoi(optarg);
+			write_pin_given = 1;
 			break;
 		case 'g':
 			gpio_pin = atoi(optarg);
 			break;
+		case 'r':
+			read_pin_given = 1;
+			break;
+		case 'R':
+			read_all_given = 1;
+			break;
+		case 's':
+			req_status = 1;
+			break;
 		default:
 			usage();
 			break;
@@ -91,7 +110,71 @@ int main(int argc, char **argv)
 	}
 
 	r = rtlsdr_open(&dev, dev_index);
-	rtlsdr_set_bias_tee_gpio(dev, gpio_pin, bias_on);
+	if (r < 0)
+	{
+		fprintf(stderr, "error opening device with index %d\n", dev_index);
+		return -r;
+	}
+
+	if (write_pin_given)
+	{
+		r = rtlsdr_set_bias_tee_gpio(dev, gpio_pin, bias_on);
+		if (r < 0)
+			fprintf(stderr, "error setting value %d on pin %d\n", bias_on, gpio_pin);
+	}
+
+	else if (read_pin_given)
+	{
+		r = rtlsdr_set_gpio_input(dev, gpio_pin);
+		if (r < 0)
+			fprintf(stderr, "error configuring pin %d to input\n", gpio_pin);
+
+		r = rtlsdr_get_gpio_bit(dev, gpio_pin, &val);
+		if (r < 0)
+			fprintf(stderr, "error reading value for pin %d\n", gpio_pin);
+		else
+			printf("value %d at pin %d\n", val, gpio_pin);
+	}
+
+	else if (read_all_given)
+	{
+		r = rtlsdr_get_gpio_byte(dev, &val);
+		if (r < 0)
+			fprintf(stderr, "error reading value for all pins\n");
+		else
+		{
+			printf("GPIO 0x%02x = bin ", val);
+			for (gpio_pin = 7; gpio_pin >= 4; --gpio_pin)
+				printf("%d", ((val >> gpio_pin) & 1));
+			printf(" ");
+			for (gpio_pin = 3; gpio_pin >= 0; --gpio_pin)
+				printf("%d", ((val >> gpio_pin) & 1));
+			printf("\n");
+		}
+	}
+
+	else if (req_status)
+	{
+		r = rtlsdr_set_gpio_status(dev, &val);
+		if (r < 0)
+			fprintf(stderr, "error reading status for all pins\n");
+		else
+		{
+			printf("STATUS 0x%02x = bin ", val);
+			for (gpio_pin = 7; gpio_pin >= 4; --gpio_pin)
+				printf("%d", ((val >> gpio_pin) & 1));
+			printf(" ");
+			for (gpio_pin = 3; gpio_pin >= 0; --gpio_pin)
+				printf("%d", ((val >> gpio_pin) & 1));
+			printf("\n");
+		}
+	}
+
+	else
+	{
+		usage();
+		r = -1;
+	}
 
 exit:
 	/*