target: Add support for IQ swap when required

Operation in GSM850 band requires IQ swap because of the offset PLL
used in the TRF causing spectrum reversal.

Thanks to Dieter Spaar for noticing the issue and the original patch

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

12 files changed, 82 insertions, 8 deletions

diff --git a/src/target/firmware/board/compal/rffe_dualband.c b/src/target/firmware/board/compal/rffe_dualband.c
index f4b73618..de161899 100644
--- a/src/target/firmware/board/compal/rffe_dualband.c
+++ b/src/target/firmware/board/compal/rffe_dualband.c
@@ -55,6 +55,12 @@ uint32_t rffe_get_tx_ports(void)
 	return (1 << PORT_LO) | (1 << PORT_HI);
 }
 
+/* Returns need for IQ swap */
+int rffe_iq_swapped(uint16_t band_arfcn, int tx)
+{
+	return trf6151_iq_swapped(band_arfcn, tx);
+}
+
 
 #define MCU_SW_TRACE	0xfffef00e
 #define ARM_CONF_REG	0xfffef006
diff --git a/src/target/firmware/board/compal_e86/rffe_dualband_e86.c b/src/target/firmware/board/compal_e86/rffe_dualband_e86.c
index 25bb0997..4ad85dcd 100644
--- a/src/target/firmware/board/compal_e86/rffe_dualband_e86.c
+++ b/src/target/firmware/board/compal_e86/rffe_dualband_e86.c
@@ -59,6 +59,12 @@ uint32_t rffe_get_tx_ports(void)
 	return (1 << PORT_LO) | (1 << PORT_HI);
 }
 
+/* Returns need for IQ swap */
+int rffe_iq_swapped(uint16_t band_arfcn, int tx)
+{
+	return trf6151_iq_swapped(band_arfcn, tx);
+}
+
 
 #define MCU_SW_TRACE	0xfffef00e
 #define ARM_CONF_REG	0xfffef006
diff --git a/src/target/firmware/board/gta0x/rffe_gta0x_triband.c b/src/target/firmware/board/gta0x/rffe_gta0x_triband.c
index f118d291..b520f656 100644
--- a/src/target/firmware/board/gta0x/rffe_gta0x_triband.c
+++ b/src/target/firmware/board/gta0x/rffe_gta0x_triband.c
@@ -84,6 +84,12 @@ uint32_t rffe_get_tx_ports(void)
 	return (1 << PORT_LO) | (1 << PORT_HI);
 }
 
+/* Returns need for IQ swap */
+int rffe_iq_swapped(uint16_t band_arfcn, int tx)
+{
+	return trf6151_iq_swapped(band_arfcn, tx);
+}
+
 
 #define MCU_SW_TRACE	0xfffef00e
 #define ARM_CONF_REG	0xfffef006
diff --git a/src/target/firmware/board/pirelli_dpl10/rffe_dpl10_triband.c b/src/target/firmware/board/pirelli_dpl10/rffe_dpl10_triband.c
index d4d13424..b3ec0d4b 100644
--- a/src/target/firmware/board/pirelli_dpl10/rffe_dpl10_triband.c
+++ b/src/target/firmware/board/pirelli_dpl10/rffe_dpl10_triband.c
@@ -83,6 +83,12 @@ uint32_t rffe_get_tx_ports(void)
 	return (1 << PORT_LO) | (1 << PORT_HI);
 }
 
+/* Returns need for IQ swap */
+int rffe_iq_swapped(uint16_t band_arfcn, int tx)
+{
+	return trf6151_iq_swapped(band_arfcn, tx);
+}
+
 
 #define MCU_SW_TRACE	0xfffef00e
 #define ARM_CONF_REG	0xfffef006
diff --git a/src/target/firmware/include/calypso/dsp.h b/src/target/firmware/include/calypso/dsp.h
index e4801cbf..4f391a7a 100644
--- a/src/target/firmware/include/calypso/dsp.h
+++ b/src/target/firmware/include/calypso/dsp.h
@@ -2,6 +2,7 @@
 #define _CALYPSO_DSP_H
 
 #include <calypso/dsp_api.h>
+#include <rffe.h>
 
 #define CAL_DSP_TGT_BB_LVL	80
 
@@ -38,4 +39,12 @@ void dsp_end_scenario(void);
 void dsp_load_rx_task(uint16_t task, uint8_t burst_id, uint8_t tsc);
 void dsp_load_tx_task(uint16_t task, uint8_t burst_id, uint8_t tsc);
 
+static inline uint16_t
+dsp_task_iq_swap(uint16_t dsp_task, uint16_t band_arfcn, int tx)
+{
+	if (rffe_iq_swapped(band_arfcn, tx))
+		dsp_task |= 0x8000;
+	return dsp_task;
+}
+
 #endif
diff --git a/src/target/firmware/include/rf/trf6151.h b/src/target/firmware/include/rf/trf6151.h
index c1eaf3b2..6a23d8ac 100644
--- a/src/target/firmware/include/rf/trf6151.h
+++ b/src/target/firmware/include/rf/trf6151.h
@@ -48,4 +48,7 @@ void trf6151_tx_window(int16_t start_qbits, uint16_t arfcn);
  * dBm, configure the RF Frontend with the respective gain */
 void trf6151_compute_gain(int16_t exp_inp, int16_t target_bb);
 
+/* Need for IQ swap */
+int trf6151_iq_swapped(uint16_t band_arfcn, int tx);
+
 #endif /* TRF6151_H */
diff --git a/src/target/firmware/include/rffe.h b/src/target/firmware/include/rffe.h
index 63a3a4b5..02fc1fda 100644
--- a/src/target/firmware/include/rffe.h
+++ b/src/target/firmware/include/rffe.h
@@ -25,6 +25,9 @@ enum rffe_port
 uint32_t rffe_get_rx_ports(void);
 uint32_t rffe_get_tx_ports(void);
 
+/* IQ swap requirements */
+int rffe_iq_swapped(uint16_t band_arfcn, int tx);
+
 /* get current gain of RF frontend (anything between antenna and baseband in dBm */
 uint8_t rffe_get_gain(void);
 
diff --git a/src/target/firmware/layer1/prim_rach.c b/src/target/firmware/layer1/prim_rach.c
index 27e89abb..08353efb 100644
--- a/src/target/firmware/layer1/prim_rach.c
+++ b/src/target/firmware/layer1/prim_rach.c
@@ -60,6 +60,7 @@ static int l1s_tx_rach_cmd(__unused uint8_t p1, __unused uint8_t p2, __unused ui
 {
 	int i;
 	uint16_t  *info_ptr;
+	uint16_t arfcn;
 	uint8_t data[2];
 
 	putchart('T');
@@ -72,9 +73,11 @@ static int l1s_tx_rach_cmd(__unused uint8_t p1, __unused uint8_t p2, __unused ui
 	info_ptr = &dsp_api.ndb->d_rach;
 	info_ptr[0] = ((uint16_t)(data[0])) | ((uint16_t)(data[1])<<8);
 
-	dsp_api.db_w->d_task_ra = RACH_DSP_TASK;
+	arfcn = l1s.serving_cell.arfcn;
 
-	l1s_tx_win_ctrl(l1s.serving_cell.arfcn | ARFCN_UPLINK, L1_TXWIN_AB, 0, 3);
+	dsp_api.db_w->d_task_ra = dsp_task_iq_swap(RACH_DSP_TASK, arfcn, 1);
+
+	l1s_tx_win_ctrl(arfcn | ARFCN_UPLINK, L1_TXWIN_AB, 0, 3);
 
 	return 0;
 }
diff --git a/src/target/firmware/layer1/prim_rx_nb.c b/src/target/firmware/layer1/prim_rx_nb.c
index ade23a01..38c7b53b 100644
--- a/src/target/firmware/layer1/prim_rx_nb.c
+++ b/src/target/firmware/layer1/prim_rx_nb.c
@@ -199,7 +199,10 @@ static int l1s_nb_cmd(__unused uint8_t p1, uint8_t burst_id,
 	dsp_load_tch_param(&l1s.next_time,
 	                   SIG_ONLY_MODE, SDCCH_4, 0, 0, 0, tn);
 
-	dsp_load_rx_task(ALLC_DSP_TASK, burst_id, tsc);
+	dsp_load_rx_task(
+		dsp_task_iq_swap(ALLC_DSP_TASK, arfcn, 0),
+		burst_id, tsc
+	);
 
 	l1s_rx_win_ctrl(arfcn, L1_RXWIN_NB, 0);
 
diff --git a/src/target/firmware/layer1/prim_tch.c b/src/target/firmware/layer1/prim_tch.c
index a26c58ea..a0a03b81 100644
--- a/src/target/firmware/layer1/prim_tch.c
+++ b/src/target/firmware/layer1/prim_tch.c
@@ -475,10 +475,16 @@ skip_tx_traffic:
 		0, sync, tn
 	);
 
-	dsp_load_rx_task(TCHT_DSP_TASK, 0, tsc); /* burst_id unused for TCH */
+	dsp_load_rx_task(
+		dsp_task_iq_swap(TCHT_DSP_TASK, arfcn, 0),
+		0, tsc		/* burst_id unused for TCH */
+	);
 	l1s_rx_win_ctrl(arfcn, L1_RXWIN_NB, 0);
 
-	dsp_load_tx_task(TCHT_DSP_TASK, 0, tsc); /* burst_id unused for TCH */
+	dsp_load_tx_task(
+		dsp_task_iq_swap(TCHT_DSP_TASK, arfcn, 1),
+		0, tsc		/* burst_id unused for TCH */
+	);
 	l1s_tx_win_ctrl(arfcn | ARFCN_UPLINK, L1_TXWIN_NB, 0, 3);
 
 	return 0;
@@ -734,10 +740,16 @@ static int l1s_tch_a_cmd(__unused uint8_t p1, __unused uint8_t p2, uint16_t p3)
 		0, 0, tn
 	);
 
-	dsp_load_rx_task(TCHA_DSP_TASK, 0, tsc); /* burst_id unused for TCHA */
+	dsp_load_rx_task(
+		dsp_task_iq_swap(TCHA_DSP_TASK, arfcn, 0),
+		0, tsc		/* burst_id unused for TCHA */
+	);
 	l1s_rx_win_ctrl(arfcn, L1_RXWIN_NB, 0);
 
-	dsp_load_tx_task(TCHA_DSP_TASK, 0, tsc); /* burst_id unused for TCHA */
+	dsp_load_tx_task(
+		dsp_task_iq_swap(TCHA_DSP_TASK, arfcn, 1),
+		0, tsc		/* burst_id unused for TCHA */
+	);
 	l1s_tx_win_ctrl(arfcn | ARFCN_UPLINK, L1_TXWIN_NB, 0, 3);
 
 	return 0;
diff --git a/src/target/firmware/layer1/prim_tx_nb.c b/src/target/firmware/layer1/prim_tx_nb.c
index df13c757..71b32eba 100644
--- a/src/target/firmware/layer1/prim_tx_nb.c
+++ b/src/target/firmware/layer1/prim_tx_nb.c
@@ -121,7 +121,10 @@ static int l1s_tx_cmd(uint8_t p1, uint8_t burst_id, uint16_t p3)
 		dsp_load_tch_param(&l1s.next_time,
 		                   SIG_ONLY_MODE, SDCCH_4, 0, 0, 0, tn);
 
-	dsp_load_tx_task(DUL_DSP_TASK, burst_id, tsc);
+	dsp_load_tx_task(
+		dsp_task_iq_swap(DUL_DSP_TASK, arfcn, 1),
+		burst_id, tsc
+	);
 
 	l1s_tx_win_ctrl(arfcn | ARFCN_UPLINK, L1_TXWIN_NB, 0, 3);
 
diff --git a/src/target/firmware/rf/trf6151.c b/src/target/firmware/rf/trf6151.c
index 96210fc6..0a910091 100644
--- a/src/target/firmware/rf/trf6151.c
+++ b/src/target/firmware/rf/trf6151.c
@@ -603,3 +603,17 @@ void trf6151_compute_gain(int16_t exp_inp, int16_t target_bb)
 	trf6151_set_gain(delta);
 }
 
+int trf6151_iq_swapped(uint16_t band_arfcn, int tx)
+{
+	if (!tx)
+		return 0;
+
+	switch (gsm_arfcn2band(band_arfcn)) {
+		case GSM_BAND_850:
+			return 1;
+		default:
+			break;
+	}
+
+	return 0;
+}