32 void at91_init_twi_bus_master(struct at91_twi_dev *dev)  in at91_init_twi_bus_master()  argument
35 	if (dev->fifo_size)  in at91_init_twi_bus_master()
36 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_FIFOEN);  in at91_init_twi_bus_master()
37 	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN);  in at91_init_twi_bus_master()
38 	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS);  in at91_init_twi_bus_master()
39 	at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg);  in at91_init_twi_bus_master()
46 static void at91_calc_twi_clock(struct at91_twi_dev *dev)  in at91_calc_twi_clock()  argument
49 	struct at91_twi_pdata *pdata = dev->pdata;  in at91_calc_twi_clock()
54 	i2c_parse_fw_timings(dev->dev, t, true);  in at91_calc_twi_clock()
56 	div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk),  in at91_calc_twi_clock()
62 		dev_warn(dev->dev, "%d exceeds ckdiv max value which is %d.\n",  in at91_calc_twi_clock()
75 				    * (clk_get_rate(dev->clk) / 1000), 1000000);  in at91_calc_twi_clock()
80 			dev_warn(dev->dev,  in at91_calc_twi_clock()
87 	dev->twi_cwgr_reg = (ckdiv << 16) | (cdiv << 8) | cdiv  in at91_calc_twi_clock()
90 	dev_dbg(dev->dev, "cdiv %d ckdiv %d hold %d (%d ns)\n",  in at91_calc_twi_clock()
94 static void at91_twi_dma_cleanup(struct at91_twi_dev *dev)  in at91_twi_dma_cleanup()  argument
96 	struct at91_twi_dma *dma = &dev->dma;  in at91_twi_dma_cleanup()
98 	at91_twi_irq_save(dev);  in at91_twi_dma_cleanup()
108 		dma_unmap_single(dev->dev, sg_dma_address(&dma->sg[0]),  in at91_twi_dma_cleanup()
109 				 dev->buf_len, dma->direction);  in at91_twi_dma_cleanup()
113 	at91_twi_irq_restore(dev);  in at91_twi_dma_cleanup()
116 static void at91_twi_write_next_byte(struct at91_twi_dev *dev)  in at91_twi_write_next_byte()  argument
118 	if (!dev->buf_len)  in at91_twi_write_next_byte()
122 	writeb_relaxed(*dev->buf, dev->base + AT91_TWI_THR);  in at91_twi_write_next_byte()
125 	if (--dev->buf_len == 0) {  in at91_twi_write_next_byte()
126 		if (!dev->use_alt_cmd)  in at91_twi_write_next_byte()
127 			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);  in at91_twi_write_next_byte()
128 		at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_TXRDY);  in at91_twi_write_next_byte()
131 	dev_dbg(dev->dev, "wrote 0x%x, to go %zu\n", *dev->buf, dev->buf_len);  in at91_twi_write_next_byte()
133 	++dev->buf;  in at91_twi_write_next_byte()
138 	struct at91_twi_dev *dev = (struct at91_twi_dev *)data;  in at91_twi_write_data_dma_callback()  local
140 	dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg[0]),  in at91_twi_write_data_dma_callback()
141 			 dev->buf_len, DMA_TO_DEVICE);  in at91_twi_write_data_dma_callback()
150 	at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP);  in at91_twi_write_data_dma_callback()
151 	if (!dev->use_alt_cmd)  in at91_twi_write_data_dma_callback()
152 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);  in at91_twi_write_data_dma_callback()
155 static void at91_twi_write_data_dma(struct at91_twi_dev *dev)  in at91_twi_write_data_dma()  argument
159 	struct at91_twi_dma *dma = &dev->dma;  in at91_twi_write_data_dma()
163 	if (!dev->buf_len)  in at91_twi_write_data_dma()
168 	at91_twi_irq_save(dev);  in at91_twi_write_data_dma()
169 	dma_addr = dma_map_single(dev->dev, dev->buf, dev->buf_len,  in at91_twi_write_data_dma()
171 	if (dma_mapping_error(dev->dev, dma_addr)) {  in at91_twi_write_data_dma()
172 		dev_err(dev->dev, "dma map failed\n");  in at91_twi_write_data_dma()
176 	at91_twi_irq_restore(dev);  in at91_twi_write_data_dma()
178 	if (dev->fifo_size) {  in at91_twi_write_data_dma()
185 		part1_len = dev->buf_len & ~0x3;  in at91_twi_write_data_dma()
192 		part2_len = dev->buf_len & 0x3;  in at91_twi_write_data_dma()
203 		fifo_mr = at91_twi_read(dev, AT91_TWI_FMR);  in at91_twi_write_data_dma()
206 		at91_twi_write(dev, AT91_TWI_FMR, fifo_mr);  in at91_twi_write_data_dma()
208 		sg_dma_len(&dma->sg[0]) = dev->buf_len;  in at91_twi_write_data_dma()
216 		dev_err(dev->dev, "dma prep slave sg failed\n");  in at91_twi_write_data_dma()
221 	txdesc->callback_param = dev;  in at91_twi_write_data_dma()
230 	at91_twi_dma_cleanup(dev);  in at91_twi_write_data_dma()
233 static void at91_twi_read_next_byte(struct at91_twi_dev *dev)  in at91_twi_read_next_byte()  argument
239 	if (!dev->buf_len) {  in at91_twi_read_next_byte()
240 		at91_twi_read(dev, AT91_TWI_RHR);  in at91_twi_read_next_byte()
245 	*dev->buf = readb_relaxed(dev->base + AT91_TWI_RHR);  in at91_twi_read_next_byte()
246 	--dev->buf_len;  in at91_twi_read_next_byte()
249 	if (dev->recv_len_abort)  in at91_twi_read_next_byte()
253 	if (unlikely(dev->msg->flags & I2C_M_RECV_LEN)) {  in at91_twi_read_next_byte()
255 		if (*dev->buf <= I2C_SMBUS_BLOCK_MAX && *dev->buf > 0) {  in at91_twi_read_next_byte()
256 			dev->msg->flags &= ~I2C_M_RECV_LEN;  in at91_twi_read_next_byte()
257 			dev->buf_len += *dev->buf;  in at91_twi_read_next_byte()
258 			dev->msg->len = dev->buf_len + 1;  in at91_twi_read_next_byte()
259 			dev_dbg(dev->dev, "received block length %zu\n",  in at91_twi_read_next_byte()
260 					 dev->buf_len);  in at91_twi_read_next_byte()
263 			dev->recv_len_abort = true;  in at91_twi_read_next_byte()
264 			dev->buf_len = 1;  in at91_twi_read_next_byte()
269 	if (!dev->use_alt_cmd && dev->buf_len == 1)  in at91_twi_read_next_byte()
270 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_STOP);  in at91_twi_read_next_byte()
272 	dev_dbg(dev->dev, "read 0x%x, to go %zu\n", *dev->buf, dev->buf_len);  in at91_twi_read_next_byte()
274 	++dev->buf;  in at91_twi_read_next_byte()
279 	struct at91_twi_dev *dev = (struct at91_twi_dev *)data;  in at91_twi_read_data_dma_callback()  local
282 	dma_unmap_single(dev->dev, sg_dma_address(&dev->dma.sg[0]),  in at91_twi_read_data_dma_callback()
283 			 dev->buf_len, DMA_FROM_DEVICE);  in at91_twi_read_data_dma_callback()
285 	if (!dev->use_alt_cmd) {  in at91_twi_read_data_dma_callback()
287 		dev->buf += dev->buf_len - 2;  in at91_twi_read_data_dma_callback()
288 		dev->buf_len = 2;  in at91_twi_read_data_dma_callback()
291 	at91_twi_write(dev, AT91_TWI_IER, ier);  in at91_twi_read_data_dma_callback()
294 static void at91_twi_read_data_dma(struct at91_twi_dev *dev)  in at91_twi_read_data_dma()  argument
298 	struct at91_twi_dma *dma = &dev->dma;  in at91_twi_read_data_dma()
302 	buf_len = (dev->use_alt_cmd) ? dev->buf_len : dev->buf_len - 2;  in at91_twi_read_data_dma()
306 	at91_twi_irq_save(dev);  in at91_twi_read_data_dma()
307 	dma_addr = dma_map_single(dev->dev, dev->buf, buf_len, DMA_FROM_DEVICE);  in at91_twi_read_data_dma()
308 	if (dma_mapping_error(dev->dev, dma_addr)) {  in at91_twi_read_data_dma()
309 		dev_err(dev->dev, "dma map failed\n");  in at91_twi_read_data_dma()
313 	at91_twi_irq_restore(dev);  in at91_twi_read_data_dma()
315 	if (dev->fifo_size && IS_ALIGNED(buf_len, 4)) {  in at91_twi_read_data_dma()
322 		fifo_mr = at91_twi_read(dev, AT91_TWI_FMR);  in at91_twi_read_data_dma()
325 		at91_twi_write(dev, AT91_TWI_FMR, fifo_mr);  in at91_twi_read_data_dma()
334 		dev_err(dev->dev, "dma prep slave sg failed\n");  in at91_twi_read_data_dma()
339 	rxdesc->callback_param = dev;  in at91_twi_read_data_dma()
348 	at91_twi_dma_cleanup(dev);  in at91_twi_read_data_dma()
353 	struct at91_twi_dev *dev = dev_id;  in atmel_twi_interrupt()  local
354 	const unsigned status = at91_twi_read(dev, AT91_TWI_SR);  in atmel_twi_interrupt()
355 	const unsigned irqstatus = status & at91_twi_read(dev, AT91_TWI_IMR);  in atmel_twi_interrupt()
382 			at91_twi_read_next_byte(dev);  in atmel_twi_interrupt()
383 		} while (at91_twi_read(dev, AT91_TWI_SR) & AT91_TWI_RXRDY);  in atmel_twi_interrupt()
425 		at91_disable_twi_interrupts(dev);  in atmel_twi_interrupt()
426 		complete(&dev->cmd_complete);  in atmel_twi_interrupt()
428 		at91_twi_write_next_byte(dev);  in atmel_twi_interrupt()
432 	dev->transfer_status |= status;  in atmel_twi_interrupt()
437 static int at91_do_twi_transfer(struct at91_twi_dev *dev)  in at91_do_twi_transfer()  argument
441 	bool has_unre_flag = dev->pdata->has_unre_flag;  in at91_do_twi_transfer()
442 	bool has_alt_cmd = dev->pdata->has_alt_cmd;  in at91_do_twi_transfer()
487 	dev_dbg(dev->dev, "transfer: %s %zu bytes.\n",  in at91_do_twi_transfer()
488 		(dev->msg->flags & I2C_M_RD) ? "read" : "write", dev->buf_len);  in at91_do_twi_transfer()
490 	reinit_completion(&dev->cmd_complete);  in at91_do_twi_transfer()
491 	dev->transfer_status = 0;  in at91_do_twi_transfer()
494 	at91_twi_read(dev, AT91_TWI_SR);  in at91_do_twi_transfer()
496 	if (dev->fifo_size) {  in at91_do_twi_transfer()
497 		unsigned fifo_mr = at91_twi_read(dev, AT91_TWI_FMR);  in at91_do_twi_transfer()
504 		at91_twi_write(dev, AT91_TWI_FMR, fifo_mr);  in at91_do_twi_transfer()
507 		at91_twi_write(dev, AT91_TWI_CR,  in at91_do_twi_transfer()
511 	if (!dev->buf_len) {  in at91_do_twi_transfer()
512 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_QUICK);  in at91_do_twi_transfer()
513 		at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_TXCOMP);  in at91_do_twi_transfer()
514 	} else if (dev->msg->flags & I2C_M_RD) {  in at91_do_twi_transfer()
518 		if (!dev->use_alt_cmd && dev->buf_len <= 1 &&  in at91_do_twi_transfer()
519 		    !(dev->msg->flags & I2C_M_RECV_LEN))  in at91_do_twi_transfer()
521 		at91_twi_write(dev, AT91_TWI_CR, start_flags);  in at91_do_twi_transfer()
531 		if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) {  in at91_do_twi_transfer()
532 			at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_NACK);  in at91_do_twi_transfer()
533 			at91_twi_read_data_dma(dev);  in at91_do_twi_transfer()
535 			at91_twi_write(dev, AT91_TWI_IER,  in at91_do_twi_transfer()
541 		if (dev->use_dma && (dev->buf_len > AT91_I2C_DMA_THRESHOLD)) {  in at91_do_twi_transfer()
542 			at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_NACK);  in at91_do_twi_transfer()
543 			at91_twi_write_data_dma(dev);  in at91_do_twi_transfer()
545 			at91_twi_write_next_byte(dev);  in at91_do_twi_transfer()
546 			at91_twi_write(dev, AT91_TWI_IER,  in at91_do_twi_transfer()
548 				       (dev->buf_len ? AT91_TWI_TXRDY : 0));  in at91_do_twi_transfer()
552 	time_left = wait_for_completion_timeout(&dev->cmd_complete,  in at91_do_twi_transfer()
553 					      dev->adapter.timeout);  in at91_do_twi_transfer()
555 		dev->transfer_status |= at91_twi_read(dev, AT91_TWI_SR);  in at91_do_twi_transfer()
556 		dev_err(dev->dev, "controller timed out\n");  in at91_do_twi_transfer()
557 		at91_init_twi_bus(dev);  in at91_do_twi_transfer()
561 	if (dev->transfer_status & AT91_TWI_NACK) {  in at91_do_twi_transfer()
562 		dev_dbg(dev->dev, "received nack\n");  in at91_do_twi_transfer()
566 	if (dev->transfer_status & AT91_TWI_OVRE) {  in at91_do_twi_transfer()
567 		dev_err(dev->dev, "overrun while reading\n");  in at91_do_twi_transfer()
571 	if (has_unre_flag && dev->transfer_status & AT91_TWI_UNRE) {  in at91_do_twi_transfer()
572 		dev_err(dev->dev, "underrun while writing\n");  in at91_do_twi_transfer()
576 	if ((has_alt_cmd || dev->fifo_size) &&  in at91_do_twi_transfer()
577 	    (dev->transfer_status & AT91_TWI_LOCK)) {  in at91_do_twi_transfer()
578 		dev_err(dev->dev, "tx locked\n");  in at91_do_twi_transfer()
582 	if (dev->recv_len_abort) {  in at91_do_twi_transfer()
583 		dev_err(dev->dev, "invalid smbus block length recvd\n");  in at91_do_twi_transfer()
588 	dev_dbg(dev->dev, "transfer complete\n");  in at91_do_twi_transfer()
594 	at91_twi_dma_cleanup(dev);  in at91_do_twi_transfer()
596 	if ((has_alt_cmd || dev->fifo_size) &&  in at91_do_twi_transfer()
597 	    (dev->transfer_status & AT91_TWI_LOCK)) {  in at91_do_twi_transfer()
598 		dev_dbg(dev->dev, "unlock tx\n");  in at91_do_twi_transfer()
599 		at91_twi_write(dev, AT91_TWI_CR,  in at91_do_twi_transfer()
607 	struct at91_twi_dev *dev = i2c_get_adapdata(adap);  in at91_twi_xfer()  local
613 	dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num);  in at91_twi_xfer()
615 	ret = pm_runtime_get_sync(dev->dev);  in at91_twi_xfer()
631 		at91_twi_write(dev, AT91_TWI_IADR, internal_address);  in at91_twi_xfer()
634 	dev->use_alt_cmd = false;  in at91_twi_xfer()
636 	if (dev->pdata->has_alt_cmd) {  in at91_twi_xfer()
639 			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_ACMEN);  in at91_twi_xfer()
640 			at91_twi_write(dev, AT91_TWI_ACR,  in at91_twi_xfer()
643 			dev->use_alt_cmd = true;  in at91_twi_xfer()
645 			at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_ACMDIS);  in at91_twi_xfer()
649 	at91_twi_write(dev, AT91_TWI_MMR,  in at91_twi_xfer()
652 		       ((!dev->use_alt_cmd && is_read) ? AT91_TWI_MREAD : 0));  in at91_twi_xfer()
654 	dev->buf_len = m_start->len;  in at91_twi_xfer()
655 	dev->buf = m_start->buf;  in at91_twi_xfer()
656 	dev->msg = m_start;  in at91_twi_xfer()
657 	dev->recv_len_abort = false;  in at91_twi_xfer()
659 	ret = at91_do_twi_transfer(dev);  in at91_twi_xfer()
663 	pm_runtime_mark_last_busy(dev->dev);  in at91_twi_xfer()
664 	pm_runtime_put_autosuspend(dev->dev);  in at91_twi_xfer()
689 static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)  in at91_twi_configure_dma()  argument
693 	struct at91_twi_dma *dma = &dev->dma;  in at91_twi_configure_dma()
711 	if (dev->fifo_size)  in at91_twi_configure_dma()
723 	dma->chan_tx = dma_request_slave_channel_reason(dev->dev, "tx");  in at91_twi_configure_dma()
730 	dma->chan_rx = dma_request_slave_channel_reason(dev->dev, "rx");  in at91_twi_configure_dma()
739 		dev_err(dev->dev, "failed to configure tx channel\n");  in at91_twi_configure_dma()
746 		dev_err(dev->dev, "failed to configure rx channel\n");  in at91_twi_configure_dma()
754 	dev->use_dma = true;  in at91_twi_configure_dma()
756 	dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n",  in at91_twi_configure_dma()
763 		dev_info(dev->dev, "can't get DMA channel, continue without DMA support\n");  in at91_twi_configure_dma()
772 			  u32 phy_addr, struct at91_twi_dev *dev)  in at91_twi_probe_master()  argument
776 	init_completion(&dev->cmd_complete);  in at91_twi_probe_master()
778 	rc = devm_request_irq(&pdev->dev, dev->irq, atmel_twi_interrupt, 0,  in at91_twi_probe_master()
779 			      dev_name(dev->dev), dev);  in at91_twi_probe_master()
781 		dev_err(dev->dev, "Cannot get irq %d: %d\n", dev->irq, rc);  in at91_twi_probe_master()
785 	if (dev->dev->of_node) {  in at91_twi_probe_master()
786 		rc = at91_twi_configure_dma(dev, phy_addr);  in at91_twi_probe_master()
791 	if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",  in at91_twi_probe_master()
792 				  &dev->fifo_size)) {  in at91_twi_probe_master()
793 		dev_info(dev->dev, "Using FIFO (%u data)\n", dev->fifo_size);  in at91_twi_probe_master()
796 	at91_calc_twi_clock(dev);  in at91_twi_probe_master()
798 	dev->adapter.algo = &at91_twi_algorithm;  in at91_twi_probe_master()
799 	dev->adapter.quirks = &at91_twi_quirks;  in at91_twi_probe_master()