/* TPU window control routines for Layer 1 */ /* (C) 2010 by Harald Welte * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * */ #include #include #include #include #include #include #include #include #include /* all units in GSM quarter-bits (923.1ns) */ #define L1_TDMA_LENGTH_Q 5000 #define L1_BURST_LENGTH_Q 625 /* L1_TDMA_LENGTH_Q/8 */ #define L1_NB_MARGIN_Q (3 * 4) #define L1_SB_MARGIN_Q (23 * 4) #define L1_TAIL_DURATION_Q (3 * 4) /* Sample length as required by the Calypso DSP */ #define L1_NB_DURATION_Q (L1_BURST_LENGTH_Q + 2 * L1_NB_MARGIN_Q - L1_TAIL_DURATION_Q) #define L1_SB_DURATION_Q (L1_BURST_LENGTH_Q + 2 * L1_SB_MARGIN_Q - L1_TAIL_DURATION_Q) #define L1_FB_DURATION_Q (11 * L1_TDMA_LENGTH_Q + 2057) /* more than 11 full slots */ #define L1_FB26_DURATION_Q (L1_TDMA_LENGTH_Q + 798) #define L1_PW_DURATION_Q 289 #define DSP_SETUP_TIME 66 static const uint16_t rx_burst_duration[_NUM_L1_RXWIN] = { [L1_RXWIN_PW] = L1_PW_DURATION_Q, [L1_RXWIN_FB] = L1_FB_DURATION_Q, [L1_RXWIN_SB] = L1_SB_DURATION_Q, [L1_RXWIN_NB] = L1_NB_DURATION_Q, }; #define L1_TX_NB_DURATION_Q 626 #define L1_TX_AB_DURATION_Q 386 static const uint16_t tx_burst_duration[_NUM_L1_TXWIN] = { [L1_TXWIN_NB] = L1_TX_NB_DURATION_Q, [L1_TXWIN_AB] = L1_TX_AB_DURATION_Q, }; void l1s_rx_win_ctrl(uint16_t arfcn, enum l1_rxwin_type wtype) { int16_t start = DSP_SETUP_TIME; int16_t stop = start + rx_burst_duration[wtype] - 1; /* FIXME: AGC */ /* FIXME: RF PLL */ /* window open for TRF6151 */ /* FIXME: why do we need the magic value 100 ? */ rffe_mode(gsm_arfcn2band(arfcn), 0); trf6151_rx_window(start - 100, arfcn, 40, 0); /* Window open for ABB */ twl3025_downlink(1, start); /* Delay 11 full TDMA frames */ if (wtype == L1_RXWIN_FB) { uint8_t i; for (i = 0; i < 11; i++) tpu_enq_at(0); stop -= 11 * L1_TDMA_LENGTH_Q; } /* Window close for ABB */ twl3025_downlink(0, stop); /* window close for TRF6151 */ trf6151_set_mode(TRF6151_IDLE); } void l1s_tx_win_ctrl(uint16_t arfcn, enum l1_txwin_type wtype, uint8_t pwr) { /* uplink is three TS after downlink ( "+ 32" gives a TA of 1) */ uint16_t offset = (L1_BURST_LENGTH_Q * 3) + 28; /* this is needed to cause a delay of one more TDMA frame, * otherwise we have an off-by-one error and send the bursts * at the wrong point in time, resulting in only 3 out of 4 * bursts arriving at the BTS */ tpu_enq_at(5000 - 10); /* TPU_CLOCK_RANGE - EPSILON_SYNC */ #ifdef CONFIG_TX_ENABLE /* window open for TRF6151 and RFFE */ rffe_mode(gsm_arfcn2band(arfcn), 1); trf6151_tx_window(offset, arfcn); #endif /* Window open for ABB */ twl3025_uplink(1, offset); /* Window close for ABB */ twl3025_uplink(0, tx_burst_duration[wtype] + offset + 2); // TODO: "+ 2" /* window close for TRF6151 and RFFE */ trf6151_set_mode(TRF6151_IDLE); } void tpu_end_scenario(void) { tpu_enq_sleep(); tpu_enable(1); }