From b1e058c81375f8ba955a86d0423fc42d718548ad Mon Sep 17 00:00:00 2001
From: Vladisslav P <vladisslav@inbox.ru>
Date: Thu, 7 Apr 2022 00:35:21 +0300
Subject: [PATCH] add bias tee support (purple dongle)

---
 include/mirisdr.h |  2 ++
 src/libmirisdr.c  |  1 +
 src/soft.c        | 22 +++++++++++++++++++++-
 src/structs.h     |  2 ++
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/include/mirisdr.h b/include/mirisdr.h
index b5c91a2..31b8b52 100644
--- a/include/mirisdr.h
+++ b/include/mirisdr.h
@@ -124,6 +124,8 @@ MIRISDR_API int mirisdr_get_mixer_gain (mirisdr_dev_t *p);              /* extra
 MIRISDR_API int mirisdr_get_mixbuffer_gain (mirisdr_dev_t *p);          /* extra */
 MIRISDR_API int mirisdr_get_lna_gain (mirisdr_dev_t *p);                /* extra */
 MIRISDR_API int mirisdr_get_baseband_gain (mirisdr_dev_t *p);           /* extra */
+MIRISDR_API int mirisdr_set_bias (mirisdr_dev_t *p, int bias);          /* extra */
+MIRISDR_API int mirisdr_get_bias (mirisdr_dev_t *p);                    /* extra */
 
 #ifdef __cplusplus
 }
diff --git a/src/libmirisdr.c b/src/libmirisdr.c
index ecc7bd6..9e375ef 100644
--- a/src/libmirisdr.c
+++ b/src/libmirisdr.c
@@ -147,6 +147,7 @@ int mirisdr_open (mirisdr_dev_t **p, uint32_t index) {
     dev->format_auto = MIRISDR_FORMAT_AUTO_ON;
     dev->bandwidth = MIRISDR_BW_8MHZ;
     dev->xtal = MIRISDR_XTAL_24M;
+    dev->bias = 0;
 
     dev->hw_flavour = MIRISDR_HW_DEFAULT;
 
diff --git a/src/soft.c b/src/soft.c
index 1df4f34..d008b02 100644
--- a/src/soft.c
+++ b/src/soft.c
@@ -58,6 +58,13 @@ hw_switch_freq_plan_t *hw_switch_freq_plan[2] = {
         hw_switch_freq_plan_sdrplay
 };
 
+#define BIAS_GPIO 3
+
+void update_reg_8(mirisdr_dev_t *p)
+{
+    mirisdr_write_reg(p, 0x08, p->reg8|(p->bias?(1<<(BIAS_GPIO+8)):0));
+}
+
 int mirisdr_set_soft(mirisdr_dev_t *p)
 {
     uint32_t reg0 = 0, reg2 = 2, reg5 = 5, reg3 = 3;
@@ -313,7 +320,9 @@ int mirisdr_set_soft(mirisdr_dev_t *p)
 //        mirisdr_write_reg(p, 0x08, band_select[i]);
 //    }
 
-    mirisdr_write_reg(p, 0x08, switch_plan.band_select_word);
+    //mirisdr_write_reg(p, 0x08, switch_plan.band_select_word);
+    p->reg8=switch_plan.band_select_word;
+    update_reg_8(p);
 
     mirisdr_write_reg(p, 0x09, 0x0e);
     mirisdr_write_reg(p, 0x09, reg3);
@@ -590,3 +599,14 @@ mirisdr_band_t mirisdr_get_band (mirisdr_dev_t *p)
     return p->band;
 }
 
+int mirisdr_set_bias (mirisdr_dev_t *p, int bias)
+{
+	p->bias=bias;
+	update_reg_8(p);
+	return 0;
+}
+
+int mirisdr_get_bias (mirisdr_dev_t *p)
+{
+	return p->bias;
+}
diff --git a/src/structs.h b/src/structs.h
index 150dcae..b0ab7c4 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -96,5 +96,7 @@ struct mirisdr_dev {
     unsigned char       *xfer_out;
     uint32_t            addr;
     int                 driver_active;
+    int                 bias;
+    int                 reg8;
 };