1 // SPDX-License-Identifier: GPL-2.0
3 // Driver for AT91 USART Controllers as SPI
12 #include <linux/dma-direction.h>
69 	readl_relaxed((port)->regs + US_##reg)
71 	writel_relaxed((value), (port)->regs + US_##reg)
74 	readb_relaxed((port)->regs + US_##reg)
76 	writeb_relaxed((value), (port)->regs + US_##reg)
109 	aus->current_rx_remaining_bytes = 0;  in dma_callback()
110 	complete(&aus->xfer_completion);  in dma_callback()
119 	return aus->use_dma && xfer->len >= US_DMA_MIN_BYTES;  in at91_usart_spi_can_dma()
126 	struct device *dev = &aus->mpdev->dev;  in at91_usart_spi_configure_dma()
127 	phys_addr_t phybase = aus->phybase;  in at91_usart_spi_configure_dma()
134 	ctlr->dma_tx = dma_request_chan(dev, "tx");  in at91_usart_spi_configure_dma()
135 	if (IS_ERR(ctlr->dma_tx)) {  in at91_usart_spi_configure_dma()
136 		err = PTR_ERR(ctlr->dma_tx);  in at91_usart_spi_configure_dma()
140 	ctlr->dma_rx = dma_request_chan(dev, "rx");  in at91_usart_spi_configure_dma()
141 	if (IS_ERR(ctlr->dma_rx)) {  in at91_usart_spi_configure_dma()
142 		err = PTR_ERR(ctlr->dma_rx);  in at91_usart_spi_configure_dma()
155 	if (dmaengine_slave_config(ctlr->dma_rx, &slave_config)) {  in at91_usart_spi_configure_dma()
156 		dev_err(&ctlr->dev,  in at91_usart_spi_configure_dma()
158 		err = -EINVAL;  in at91_usart_spi_configure_dma()
163 	if (dmaengine_slave_config(ctlr->dma_tx, &slave_config)) {  in at91_usart_spi_configure_dma()
164 		dev_err(&ctlr->dev,  in at91_usart_spi_configure_dma()
166 		err = -EINVAL;  in at91_usart_spi_configure_dma()
170 	aus->use_dma = true;  in at91_usart_spi_configure_dma()
174 	if (!IS_ERR_OR_NULL(ctlr->dma_tx))  in at91_usart_spi_configure_dma()
175 		dma_release_channel(ctlr->dma_tx);  in at91_usart_spi_configure_dma()
176 	if (!IS_ERR_OR_NULL(ctlr->dma_rx))  in at91_usart_spi_configure_dma()
177 		dma_release_channel(ctlr->dma_rx);  in at91_usart_spi_configure_dma()
178 	ctlr->dma_tx = NULL;  in at91_usart_spi_configure_dma()
179 	ctlr->dma_rx = NULL;  in at91_usart_spi_configure_dma()
187 	if (ctlr->dma_rx)  in at91_usart_spi_release_dma()
188 		dma_release_channel(ctlr->dma_rx);  in at91_usart_spi_release_dma()
189 	if (ctlr->dma_tx)  in at91_usart_spi_release_dma()
190 		dma_release_channel(ctlr->dma_tx);  in at91_usart_spi_release_dma()
195 	if (ctlr->dma_rx)  in at91_usart_spi_stop_dma()
196 		dmaengine_terminate_all(ctlr->dma_rx);  in at91_usart_spi_stop_dma()
197 	if (ctlr->dma_tx)  in at91_usart_spi_stop_dma()
198 		dmaengine_terminate_all(ctlr->dma_tx);  in at91_usart_spi_stop_dma()
205 	struct dma_chan	 *rxchan = ctlr->dma_rx;  in at91_usart_spi_dma_transfer()
206 	struct dma_chan *txchan = ctlr->dma_tx;  in at91_usart_spi_dma_transfer()
215 					 xfer->rx_sg.sgl,  in at91_usart_spi_dma_transfer()
216 					 xfer->rx_sg.nents,  in at91_usart_spi_dma_transfer()
224 					 xfer->tx_sg.sgl,  in at91_usart_spi_dma_transfer()
225 					 xfer->tx_sg.nents,  in at91_usart_spi_dma_transfer()
232 	rxdesc->callback = dma_callback;  in at91_usart_spi_dma_transfer()
233 	rxdesc->callback_param = ctlr;  in at91_usart_spi_dma_transfer()
235 	cookie = rxdesc->tx_submit(rxdesc);  in at91_usart_spi_dma_transfer()
239 	cookie = txdesc->tx_submit(txdesc);  in at91_usart_spi_dma_transfer()
243 	rxchan->device->device_issue_pending(rxchan);  in at91_usart_spi_dma_transfer()
244 	txchan->device->device_issue_pending(txchan);  in at91_usart_spi_dma_transfer()
253 	return -ENOMEM;  in at91_usart_spi_dma_transfer()
258 	return wait_for_completion_timeout(&aus->xfer_completion,  in at91_usart_spi_dma_timeout()
264 	return aus->status & US_IR_TXRDY;  in at91_usart_spi_tx_ready()
269 	return aus->status & US_IR_RXRDY;  in at91_usart_spi_rx_ready()
274 	return aus->status & US_IR_OVRE;  in at91_usart_spi_check_overrun()
279 	aus->status = at91_usart_spi_readl(aus, CSR);  in at91_usart_spi_read_status()
280 	return aus->status;  in at91_usart_spi_read_status()
285 	unsigned int len = aus->current_transfer->len;  in at91_usart_spi_tx()
286 	unsigned int remaining = aus->current_tx_remaining_bytes;  in at91_usart_spi_tx()
287 	const u8  *tx_buf = aus->current_transfer->tx_buf;  in at91_usart_spi_tx()
293 		at91_usart_spi_writeb(aus, THR, tx_buf[len - remaining]);  in at91_usart_spi_tx()
294 		aus->current_tx_remaining_bytes--;  in at91_usart_spi_tx()
300 	int len = aus->current_transfer->len;  in at91_usart_spi_rx()
301 	int remaining = aus->current_rx_remaining_bytes;  in at91_usart_spi_rx()
302 	u8  *rx_buf = aus->current_transfer->rx_buf;  in at91_usart_spi_rx()
307 	rx_buf[len - remaining] = at91_usart_spi_readb(aus, RHR);  in at91_usart_spi_rx()
308 	aus->current_rx_remaining_bytes--;  in at91_usart_spi_rx()
316 			      DIV_ROUND_UP(aus->spi_clk, xfer->speed_hz));  in at91_usart_spi_set_xfer_speed()
324 	spin_lock(&aus->lock);  in at91_usart_spi_interrupt()
328 		aus->xfer_failed = true;  in at91_usart_spi_interrupt()
330 		spin_unlock(&aus->lock);  in at91_usart_spi_interrupt()
336 		spin_unlock(&aus->lock);  in at91_usart_spi_interrupt()
340 	spin_unlock(&aus->lock);  in at91_usart_spi_interrupt()
347 	struct at91_usart_spi *aus = spi_controller_get_devdata(spi->controller);  in at91_usart_spi_setup()
348 	u32 *ausd = spi->controller_state;  in at91_usart_spi_setup()
351 	if (spi->mode & SPI_CPOL)  in at91_usart_spi_setup()
356 	if (spi->mode & SPI_CPHA)  in at91_usart_spi_setup()
361 	if (spi->mode & SPI_LOOP)  in at91_usart_spi_setup()
369 			return -ENOMEM;  in at91_usart_spi_setup()
371 		spi->controller_state = ausd;  in at91_usart_spi_setup()
376 	dev_dbg(&spi->dev,  in at91_usart_spi_setup()
377 		"setup: bpw %u mode 0x%x -> mr %d %08x\n",  in at91_usart_spi_setup()
378 		spi->bits_per_word, spi->mode, spi_get_chipselect(spi, 0), mr);  in at91_usart_spi_setup()
392 	aus->xfer_failed = false;  in at91_usart_spi_transfer_one()
393 	aus->current_transfer = xfer;  in at91_usart_spi_transfer_one()
394 	aus->current_tx_remaining_bytes = xfer->len;  in at91_usart_spi_transfer_one()
395 	aus->current_rx_remaining_bytes = xfer->len;  in at91_usart_spi_transfer_one()
397 	while ((aus->current_tx_remaining_bytes ||  in at91_usart_spi_transfer_one()
398 		aus->current_rx_remaining_bytes) && !aus->xfer_failed) {  in at91_usart_spi_transfer_one()
399 		reinit_completion(&aus->xfer_completion);  in at91_usart_spi_transfer_one()
409 				dev_err(&spi->dev, "DMA transfer timeout\n");  in at91_usart_spi_transfer_one()
410 				return -EIO;  in at91_usart_spi_transfer_one()
412 			aus->current_tx_remaining_bytes = 0;  in at91_usart_spi_transfer_one()
421 	if (aus->xfer_failed) {  in at91_usart_spi_transfer_one()
422 		dev_err(aus->dev, "Overrun!\n");  in at91_usart_spi_transfer_one()
423 		return -EIO;  in at91_usart_spi_transfer_one()
433 	struct spi_device *spi = message->spi;  in at91_usart_spi_prepare_message()
434 	u32 *ausd = spi->controller_state;  in at91_usart_spi_prepare_message()
456 	struct at91_usart_spi_device *ausd = spi->controller_state;  in at91_usart_spi_cleanup()
458 	spi->controller_state = NULL;  in at91_usart_spi_cleanup()
472 	cs_gpios = devm_gpiod_get_array_optional(&pdev->dev, "cs", GPIOD_OUT_LOW);  in at91_usart_gpio_setup()
486 	regs = platform_get_resource(to_platform_device(pdev->dev.parent),  in at91_usart_spi_probe()
489 		return -EINVAL;  in at91_usart_spi_probe()
491 	irq = platform_get_irq(to_platform_device(pdev->dev.parent), 0);  in at91_usart_spi_probe()
495 	clk = devm_clk_get(pdev->dev.parent, "usart");  in at91_usart_spi_probe()
499 	ret = -ENOMEM;  in at91_usart_spi_probe()
500 	controller = spi_alloc_host(&pdev->dev, sizeof(*aus));  in at91_usart_spi_probe()
508 	controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;  in at91_usart_spi_probe()
509 	controller->dev.of_node = pdev->dev.parent->of_node;  in at91_usart_spi_probe()
510 	controller->bits_per_word_mask = SPI_BPW_MASK(8);  in at91_usart_spi_probe()
511 	controller->setup = at91_usart_spi_setup;  in at91_usart_spi_probe()
512 	controller->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;  in at91_usart_spi_probe()
513 	controller->transfer_one = at91_usart_spi_transfer_one;  in at91_usart_spi_probe()
514 	controller->prepare_message = at91_usart_spi_prepare_message;  in at91_usart_spi_probe()
515 	controller->unprepare_message = at91_usart_spi_unprepare_message;  in at91_usart_spi_probe()
516 	controller->can_dma = at91_usart_spi_can_dma;  in at91_usart_spi_probe()
517 	controller->cleanup = at91_usart_spi_cleanup;  in at91_usart_spi_probe()
518 	controller->max_speed_hz = DIV_ROUND_UP(clk_get_rate(clk),  in at91_usart_spi_probe()
520 	controller->min_speed_hz = DIV_ROUND_UP(clk_get_rate(clk),  in at91_usart_spi_probe()
526 	aus->dev = &pdev->dev;  in at91_usart_spi_probe()
527 	aus->regs = devm_ioremap_resource(&pdev->dev, regs);  in at91_usart_spi_probe()
528 	if (IS_ERR(aus->regs)) {  in at91_usart_spi_probe()
529 		ret = PTR_ERR(aus->regs);  in at91_usart_spi_probe()
533 	aus->irq = irq;  in at91_usart_spi_probe()
534 	aus->clk = clk;  in at91_usart_spi_probe()
536 	ret = devm_request_irq(&pdev->dev, irq, at91_usart_spi_interrupt, 0,  in at91_usart_spi_probe()
537 			       dev_name(&pdev->dev), controller);  in at91_usart_spi_probe()
545 	aus->spi_clk = clk_get_rate(clk);  in at91_usart_spi_probe()
548 	aus->phybase = regs->start;  in at91_usart_spi_probe()
550 	aus->mpdev = to_platform_device(pdev->dev.parent);  in at91_usart_spi_probe()
556 	spin_lock_init(&aus->lock);  in at91_usart_spi_probe()
557 	init_completion(&aus->xfer_completion);  in at91_usart_spi_probe()
559 	ret = devm_spi_register_controller(&pdev->dev, controller);  in at91_usart_spi_probe()
563 	dev_info(&pdev->dev,  in at91_usart_spi_probe()
564 		 "AT91 USART SPI Controller version 0x%x at %pa (irq %d)\n",  in at91_usart_spi_probe()
566 		 &regs->start, irq);  in at91_usart_spi_probe()
584 	clk_disable_unprepare(aus->clk);  in at91_usart_spi_runtime_suspend()
597 	return clk_prepare_enable(aus->clk);  in at91_usart_spi_runtime_resume()
638 	clk_disable_unprepare(aus->clk);  in at91_usart_spi_remove()
658 MODULE_DESCRIPTION("Microchip AT91 USART SPI Controller driver");