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>

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

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

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

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

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

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 */

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);
 

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;
 }

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);
 

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;

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);
 

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;
+}