1 // SPDX-License-Identifier: GPL-2.0-or-later
6  * Copyright (C) 2015-2018 Ondrej Ille <ondrej.ille@gmail.com> FEE CTU
7  * Copyright (C) 2018-2021 Ondrej Ille <ondrej.ille@gmail.com> self-funded
8  * Copyright (C) 2018-2019 Martin Jerabek <martin.jerabek01@gmail.com> FEE CTU
9  * Copyright (C) 2018-2022 Pavel Pisa <pisa@cmp.felk.cvut.cz> FEE CTU/self-funded
49  * - when a buffer transitions to empty state, rotate order and priorities
50  * - if more buffers seem to transition at the same time, rotate by the number of buffers
51  * - it may be assumed that buffers transition to empty state in FIFO order (because we manage
53  * - at frame filling, do not rotate anything, just increment buffer modulo counter
114 	iowrite32(val, priv->mem_base + reg);  in ctucan_write32_le()
120 	iowrite32be(val, priv->mem_base + reg);  in ctucan_write32_be()
126 	return ioread32(priv->mem_base + reg);  in ctucan_read32_le()
132 	return ioread32be(priv->mem_base + reg);  in ctucan_read32_be()
137 	priv->write_reg(priv, reg, val);  in ctucan_write32()
142 	return priv->read_reg(priv, reg);  in ctucan_read32()
148 	priv->write_reg(priv, buf_base + offset, val);  in ctucan_write_txt_buf()
155  * ctucan_state_to_str() - Converts CAN controller state code to corresponding text
170  * ctucan_reset() - Issues software reset request to CTU CAN FD
173  * Return: 0 for success, -%ETIMEDOUT if CAN controller does not leave reset
181 	clear_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags);  in ctucan_reset()
189 		if (!i--) {  in ctucan_reset()
191 			return -ETIMEDOUT;  in ctucan_reset()
198  * ctucan_set_btr() - Sets CAN bus bit timing in CTU CAN FD
200  * @bt:		Pointer to Bit timing structure
201  * @nominal:	True - Nominal bit timing, False - Data bit timing
203  * Return: 0 - OK, -%EPERM if controller is enabled
210 	u32 prop_seg = bt->prop_seg;  in ctucan_set_btr()
211 	u32 phase_seg1 = bt->phase_seg1;  in ctucan_set_btr()
214 		netdev_err(ndev, "BUG! Cannot set bittiming - CAN is enabled\n");  in ctucan_set_btr()
215 		return -EPERM;  in ctucan_set_btr()
221 	/* The timing calculation functions have only constraints on tseg1, which is prop_seg +  in ctucan_set_btr()
223 	 * In CTU CAN FD, PROP is 6/7 bits wide but PH1 only 6/5, so we must re-distribute the  in ctucan_set_btr()
227 		prop_seg += phase_seg1 - max_ph1_len;  in ctucan_set_btr()
229 		bt->prop_seg = prop_seg;  in ctucan_set_btr()
230 		bt->phase_seg1 = phase_seg1;  in ctucan_set_btr()
236 		btr |= FIELD_PREP(REG_BTR_PH2, bt->phase_seg2);  in ctucan_set_btr()
237 		btr |= FIELD_PREP(REG_BTR_BRP, bt->brp);  in ctucan_set_btr()
238 		btr |= FIELD_PREP(REG_BTR_SJW, bt->sjw);  in ctucan_set_btr()
244 		btr |= FIELD_PREP(REG_BTR_FD_PH2_FD, bt->phase_seg2);  in ctucan_set_btr()
245 		btr |= FIELD_PREP(REG_BTR_FD_BRP_FD, bt->brp);  in ctucan_set_btr()
246 		btr |= FIELD_PREP(REG_BTR_FD_SJW_FD, bt->sjw);  in ctucan_set_btr()
255  * ctucan_set_bittiming() - CAN set nominal bit timing routine
258  * Return: 0 on success, -%EPERM on error
263 	struct can_bittiming *bt = &priv->can.bittiming;  in ctucan_set_bittiming()
270  * ctucan_set_data_bittiming() - CAN set data bit timing routine
273  * Return: 0 on success, -%EPERM on error
278 	struct can_bittiming *dbt = &priv->can.fd.data_bittiming;  in ctucan_set_data_bittiming()
285  * ctucan_set_secondary_sample_point() - Sets secondary sample point in CTU CAN FD
288  * Return: 0 on success, -%EPERM if controller is enabled
293 	struct can_bittiming *dbt = &priv->can.fd.data_bittiming;  in ctucan_set_secondary_sample_point()
298 		netdev_err(ndev, "BUG! Cannot set SSP - CAN is enabled\n");  in ctucan_set_secondary_sample_point()
299 		return -EPERM;  in ctucan_set_secondary_sample_point()
302 	/* Use SSP for bit-rates above 1 Mbits/s */  in ctucan_set_secondary_sample_point()
303 	if (dbt->bitrate > 1000000) {  in ctucan_set_secondary_sample_point()
305 		ssp_offset = (priv->can.clock.freq / 1000) * dbt->sample_point / dbt->bitrate;  in ctucan_set_secondary_sample_point()
322  * ctucan_set_mode() - Sets CTU CAN FDs mode
330 	mode_reg = (mode->flags & CAN_CTRLMODE_LOOPBACK) ?  in ctucan_set_mode()
334 	mode_reg = (mode->flags & CAN_CTRLMODE_LISTENONLY) ?  in ctucan_set_mode()
338 	mode_reg = (mode->flags & CAN_CTRLMODE_FD) ?  in ctucan_set_mode()
342 	mode_reg = (mode->flags & CAN_CTRLMODE_PRESUME_ACK) ?  in ctucan_set_mode()
346 	mode_reg = (mode->flags & CAN_CTRLMODE_FD_NON_ISO) ?  in ctucan_set_mode()
352 	mode_reg = (mode->flags & CAN_CTRLMODE_ONE_SHOT) ?  in ctucan_set_mode()
357 	 *   TSTM  - Off, User shall not be able to change REC/TEC by hand during operation  in ctucan_set_mode()
365  * ctucan_chip_start() - This routine starts the driver
383 	priv->txb_prio = 0x01234567;  in ctucan_chip_start()
384 	priv->txb_head = 0;  in ctucan_chip_start()
385 	priv->txb_tail = 0;  in ctucan_chip_start()
386 	ctucan_write32(priv, CTUCANFD_TX_PRIORITY, priv->txb_prio);  in ctucan_chip_start()
388 	/* Configure bit-rates and ssp */  in ctucan_chip_start()
402 	mode.flags = priv->can.ctrlmode;  in ctucan_chip_start()
412 	/* Bus error reporting -> Allow Error/Arb.lost interrupts */  in ctucan_chip_start()
413 	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {  in ctucan_chip_start()
425 	priv->can.state = CAN_STATE_STOPPED;  in ctucan_chip_start()
436  * ctucan_do_set_mode() - Sets mode of the driver
461 		ret = -EOPNOTSUPP;  in ctucan_do_set_mode()
469  * ctucan_get_tx_status() - Gets status of TXT buffer
471  * @buf:	Buffer index (0-based)
484  * ctucan_is_txt_buf_writable() - Checks if frame can be inserted to TXT Buffer
486  * @buf:	Buffer index (0-based)
488  * Return: True - Frame can be inserted to TXT Buffer, False - If attempted, frame will not be
503  * ctucan_insert_frame() - Inserts frame to TXT buffer
506  * @buf:	TXT Buffer index to which frame is inserted (0-based)
507  * @isfdf:	True - CAN FD Frame, False - CAN 2.0 Frame
510  * * True - Frame inserted successfully
511  * * False - Frame was not inserted due to one of:
524 	if (buf >= priv->ntxbufs)  in ctucan_insert_frame()
530 	if (cf->len > CANFD_MAX_DLEN)  in ctucan_insert_frame()
534 	if (cf->can_id & CAN_RTR_FLAG)  in ctucan_insert_frame()
537 	if (cf->can_id & CAN_EFF_FLAG)  in ctucan_insert_frame()
542 		if (cf->flags & CANFD_BRS)  in ctucan_insert_frame()
546 	ffw |= FIELD_PREP(REG_FRAME_FORMAT_W_DLC, can_fd_len2dlc(cf->len));  in ctucan_insert_frame()
549 	if (cf->can_id & CAN_EFF_FLAG)  in ctucan_insert_frame()
550 		idw = cf->can_id & CAN_EFF_MASK;  in ctucan_insert_frame()
552 		idw = FIELD_PREP(REG_IDENTIFIER_W_IDENTIFIER_BASE, cf->can_id & CAN_SFF_MASK);  in ctucan_insert_frame()
554 	/* Write ID, Frame format, Don't write timestamp -> Time triggered transmission disabled */  in ctucan_insert_frame()
560 	if (!(cf->can_id & CAN_RTR_FLAG)) {  in ctucan_insert_frame()
561 		for (i = 0; i < cf->len; i += 4) {  in ctucan_insert_frame()
562 			u32 data = le32_to_cpu(*(__le32 *)(cf->data + i));  in ctucan_insert_frame()
572  * ctucan_give_txtb_cmd() - Applies command on TXT buffer
575  * @buf:	Buffer index (0-based)
586  * ctucan_start_xmit() - Starts the transmission
599 	struct canfd_frame *cf = (struct canfd_frame *)skb->data;  in ctucan_start_xmit()
613 	txtb_id = priv->txb_head % priv->ntxbufs;  in ctucan_start_xmit()
620 		ndev->stats.tx_dropped++;  in ctucan_start_xmit()
626 	spin_lock_irqsave(&priv->tx_lock, flags);  in ctucan_start_xmit()
628 	priv->txb_head++;  in ctucan_start_xmit()
634 	spin_unlock_irqrestore(&priv->tx_lock, flags);  in ctucan_start_xmit()
640  * ctucan_read_rx_frame() - Reads frame from RX FIFO
656 		cf->can_id = (idw & CAN_EFF_MASK) | CAN_EFF_FLAG;  in ctucan_read_rx_frame()
658 		cf->can_id = (idw >> 18) & CAN_SFF_MASK;  in ctucan_read_rx_frame()
663 			cf->flags |= CANFD_BRS;  in ctucan_read_rx_frame()
665 			cf->flags |= CANFD_ESI;  in ctucan_read_rx_frame()
667 		cf->can_id |= CAN_RTR_FLAG;  in ctucan_read_rx_frame()
670 	wc = FIELD_GET(REG_FRAME_FORMAT_W_RWCNT, ffw) - 3;  in ctucan_read_rx_frame()
681 	cf->len = len;  in ctucan_read_rx_frame()
685 	/* Timestamp - Read and throw away */  in ctucan_read_rx_frame()
692 		*(__le32 *)(cf->data + i) = cpu_to_le32(data);  in ctucan_read_rx_frame()
701  * ctucan_rx() -  Called from CAN ISR to complete the received frame processing
708  *         -%EAGAIN in a case of empty Rx FIFO.
713 	struct net_device_stats *stats = &ndev->stats;  in ctucan_rx()
718 	if (test_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags)) {  in ctucan_rx()
719 		ffw = priv->rxfrm_first_word;  in ctucan_rx()
720 		clear_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags);  in ctucan_rx()
726 		return -EAGAIN;  in ctucan_rx()
734 		priv->rxfrm_first_word = ffw;  in ctucan_rx()
735 		set_bit(CTUCANFD_FLAG_RX_FFW_BUFFERED, &priv->drv_flags);  in ctucan_rx()
741 	stats->rx_bytes += cf->len;  in ctucan_rx()
742 	stats->rx_packets++;  in ctucan_rx()
749  * ctucan_read_fault_state() - Reads CTU CAN FDs fault confinement state.
781  * ctucan_get_rec_tec() - Reads REC/TEC counter values from controller
789 	bec->rxerr = FIELD_GET(REG_REC_REC_VAL, err_ctrs);  in ctucan_get_rec_tec()
790 	bec->txerr = FIELD_GET(REG_REC_TEC_VAL, err_ctrs);  in ctucan_get_rec_tec()
794  * ctucan_err_interrupt() - Error frame ISR
804 	struct net_device_stats *stats = &ndev->stats;  in ctucan_err_interrupt()
833 			    ctucan_state_to_str(priv->can.state),  in ctucan_err_interrupt()
836 		if (priv->can.state == state)  in ctucan_err_interrupt()
840 		priv->can.state = state;  in ctucan_err_interrupt()
843 			priv->can.can_stats.bus_off++;  in ctucan_err_interrupt()
846 				cf->can_id |= CAN_ERR_BUSOFF;  in ctucan_err_interrupt()
849 			priv->can.can_stats.error_passive++;  in ctucan_err_interrupt()
851 				cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;  in ctucan_err_interrupt()
852 				cf->data[1] = (bec.rxerr > 127) ?  in ctucan_err_interrupt()
855 				cf->data[6] = bec.txerr;  in ctucan_err_interrupt()
856 				cf->data[7] = bec.rxerr;  in ctucan_err_interrupt()
860 			priv->can.can_stats.error_warning++;  in ctucan_err_interrupt()
862 				cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;  in ctucan_err_interrupt()
863 				cf->data[1] |= (bec.txerr > bec.rxerr) ?  in ctucan_err_interrupt()
866 				cf->data[6] = bec.txerr;  in ctucan_err_interrupt()
867 				cf->data[7] = bec.rxerr;  in ctucan_err_interrupt()
872 				cf->can_id |= CAN_ERR_CNT;  in ctucan_err_interrupt()
873 				cf->data[1] = CAN_ERR_CRTL_ACTIVE;  in ctucan_err_interrupt()
874 				cf->data[6] = bec.txerr;  in ctucan_err_interrupt()
875 				cf->data[7] = bec.rxerr;  in ctucan_err_interrupt()
889 		priv->can.can_stats.arbitration_lost++;  in ctucan_err_interrupt()
891 			cf->can_id |= CAN_ERR_LOSTARB;  in ctucan_err_interrupt()
892 			cf->data[0] = CAN_ERR_LOSTARB_UNSPEC;  in ctucan_err_interrupt()
899 		priv->can.can_stats.bus_error++;  in ctucan_err_interrupt()
900 		stats->rx_errors++;  in ctucan_err_interrupt()
902 			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;  in ctucan_err_interrupt()
903 			cf->data[2] = CAN_ERR_PROT_UNSPEC;  in ctucan_err_interrupt()
904 			cf->data[3] = CAN_ERR_PROT_LOC_UNSPEC;  in ctucan_err_interrupt()
909 		stats->rx_packets++;  in ctucan_err_interrupt()
910 		stats->rx_bytes += cf->can_dlc;  in ctucan_err_interrupt()
916  * ctucan_rx_poll() - Poll routine for rx packets (NAPI)
926 	struct net_device *ndev = napi->dev;  in ctucan_rx_poll()
943 		struct net_device_stats *stats = &ndev->stats;  in ctucan_rx_poll()
948 		stats->rx_over_errors++;  in ctucan_rx_poll()
949 		stats->rx_errors++;  in ctucan_rx_poll()
952 			cf->can_id |= CAN_ERR_CRTL;  in ctucan_rx_poll()
953 			cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;  in ctucan_rx_poll()
954 			stats->rx_packets++;  in ctucan_rx_poll()
955 			stats->rx_bytes += cf->can_dlc;  in ctucan_rx_poll()
965 			/* Clear and enable RBNEI. It is level-triggered, so  in ctucan_rx_poll()
977  * ctucan_rotate_txb_prio() - Rotates priorities of TXT Buffers
983 	u32 prio = priv->txb_prio;  in ctucan_rotate_txb_prio()
985 	prio = (prio << 4) | ((prio >> ((priv->ntxbufs - 1) * 4)) & 0xF);  in ctucan_rotate_txb_prio()
986 	ctucan_netdev_dbg(ndev, "%s: from 0x%08x to 0x%08x\n", __func__, priv->txb_prio, prio);  in ctucan_rotate_txb_prio()
987 	priv->txb_prio = prio;  in ctucan_rotate_txb_prio()
992  * ctucan_tx_interrupt() - Tx done Isr
998 	struct net_device_stats *stats = &ndev->stats;  in ctucan_tx_interrupt()
1007 	 *	if ok -> echo  in ctucan_tx_interrupt()
1008 	 *	if error / aborted -> ?? (find how to handle oneshot mode)  in ctucan_tx_interrupt()
1012 		spin_lock_irqsave(&priv->tx_lock, flags);  in ctucan_tx_interrupt()
1015 		while ((int)(priv->txb_head - priv->txb_tail) > 0) {  in ctucan_tx_interrupt()
1016 			txtb_id = priv->txb_tail % priv->ntxbufs;  in ctucan_tx_interrupt()
1024 				stats->tx_bytes += can_get_echo_skb(ndev, txtb_id, NULL);  in ctucan_tx_interrupt()
1025 				stats->tx_packets++;  in ctucan_tx_interrupt()
1035 				stats->tx_dropped++;  in ctucan_tx_interrupt()
1039 				 * re-queue the frame, but multiqueue/abort is not supported yet  in ctucan_tx_interrupt()
1044 				stats->tx_dropped++;  in ctucan_tx_interrupt()
1054 					spin_unlock_irqrestore(&priv->tx_lock, flags);  in ctucan_tx_interrupt()
1060 			priv->txb_tail++;  in ctucan_tx_interrupt()
1068 		spin_unlock_irqrestore(&priv->tx_lock, flags);  in ctucan_tx_interrupt()
1070 		/* If no buffers were processed this time, we cannot clear - that would introduce  in ctucan_tx_interrupt()
1082 	spin_lock_irqsave(&priv->tx_lock, flags);  in ctucan_tx_interrupt()
1088 	spin_unlock_irqrestore(&priv->tx_lock, flags);  in ctucan_tx_interrupt()
1092  * ctucan_interrupt() - CAN Isr
1100  * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise
1126 			napi_schedule(&priv->napi);  in ctucan_interrupt()
1155 			   priv->txb_head, priv->txb_tail);  in ctucan_interrupt()
1156 		for (i = 0; i < priv->ntxbufs; i++) {  in ctucan_interrupt()
1171  * ctucan_chip_stop() - Driver stop routine
1190 	priv->can.state = CAN_STATE_STOPPED;  in ctucan_chip_stop()
1194  * ctucan_open() - Driver open routine
1205 	ret = pm_runtime_get_sync(priv->dev);  in ctucan_open()
1209 		pm_runtime_put_noidle(priv->dev);  in ctucan_open()
1224 	ret = request_irq(ndev->irq, ctucan_interrupt, priv->irq_flags, ndev->name, ndev);  in ctucan_open()
1237 	napi_enable(&priv->napi);  in ctucan_open()
1243 	free_irq(ndev->irq, ndev);  in ctucan_open()
1248 	pm_runtime_put(priv->dev);  in ctucan_open()
1254  * ctucan_close() - Driver close routine
1264 	napi_disable(&priv->napi);  in ctucan_close()
1266 	free_irq(ndev->irq, ndev);  in ctucan_close()
1269 	pm_runtime_put(priv->dev);  in ctucan_close()
1275  * ctucan_get_berr_counter() - error counter routine
1287 	ret = pm_runtime_get_sync(priv->dev);  in ctucan_get_berr_counter()
1290 		pm_runtime_put_noidle(priv->dev);  in ctucan_get_berr_counter()
1295 	pm_runtime_put(priv->dev);  in ctucan_get_berr_counter()
1321 	priv->can.state = CAN_STATE_SLEEPING;  in ctucan_suspend()
1332 	priv->can.state = CAN_STATE_ERROR_ACTIVE;  in ctucan_resume()
1354 		return -ENOMEM;  in ctucan_probe_common()
1357 	spin_lock_init(&priv->tx_lock);  in ctucan_probe_common()
1358 	INIT_LIST_HEAD(&priv->peers_on_pdev);  in ctucan_probe_common()
1359 	priv->ntxbufs = ntxbufs;  in ctucan_probe_common()
1360 	priv->dev = dev;  in ctucan_probe_common()
1361 	priv->can.bittiming_const = &ctu_can_fd_bit_timing_max;  in ctucan_probe_common()
1362 	priv->can.fd.data_bittiming_const = &ctu_can_fd_bit_timing_data_max;  in ctucan_probe_common()
1363 	priv->can.do_set_mode = ctucan_do_set_mode;  in ctucan_probe_common()
1365 	/* Needed for timing adjustment to be performed as soon as possible */  in ctucan_probe_common()
1366 	priv->can.do_set_bittiming = ctucan_set_bittiming;  in ctucan_probe_common()
1367 	priv->can.fd.do_set_data_bittiming = ctucan_set_data_bittiming;  in ctucan_probe_common()
1369 	priv->can.do_get_berr_counter = ctucan_get_berr_counter;  in ctucan_probe_common()
1370 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK  in ctucan_probe_common()
1377 	priv->mem_base = addr;  in ctucan_probe_common()
1380 	ndev->irq = irq;  in ctucan_probe_common()
1381 	ndev->flags |= IFF_ECHO;	/* We support local echo */  in ctucan_probe_common()
1386 	ndev->netdev_ops = &ctucan_netdev_ops;  in ctucan_probe_common()
1387 	ndev->ethtool_ops = &ctucan_ethtool_ops;  in ctucan_probe_common()
1391 		priv->can_clk = devm_clk_get(dev, NULL);  in ctucan_probe_common()
1392 		if (IS_ERR(priv->can_clk)) {  in ctucan_probe_common()
1394 			ret = PTR_ERR(priv->can_clk);  in ctucan_probe_common()
1397 		can_clk_rate = clk_get_rate(priv->can_clk);  in ctucan_probe_common()
1400 	priv->write_reg = ctucan_write32_le;  in ctucan_probe_common()
1401 	priv->read_reg = ctucan_read32_le;  in ctucan_probe_common()
1409 		pm_runtime_put_noidle(priv->dev);  in ctucan_probe_common()
1413 	/* Check for big-endianity and set according IO-accessors */  in ctucan_probe_common()
1415 		priv->write_reg = ctucan_write32_be;  in ctucan_probe_common()
1416 		priv->read_reg = ctucan_read32_be;  in ctucan_probe_common()
1419 			ret = -ENODEV;  in ctucan_probe_common()
1428 	priv->can.clock.freq = can_clk_rate;  in ctucan_probe_common()
1430 	netif_napi_add(ndev, &priv->napi, ctucan_rx_poll);  in ctucan_probe_common()
1441 		   priv->mem_base, ndev->irq, priv->can.clock.freq, priv->ntxbufs);  in ctucan_probe_common()
1446 	pm_runtime_put(priv->dev);  in ctucan_probe_common()
1451 	list_del_init(&priv->peers_on_pdev);  in ctucan_probe_common()