3  * 8250_dma.c - DMA Engine API support for 8250.c
10 #include <linux/dma-mapping.h>
17 	struct uart_8250_dma	*dma = p->dma;  in __dma_tx_complete()  local
22 	dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,  in __dma_tx_complete()
27 	dma->tx_running = 0;  in __dma_tx_complete()
29 	uart_xmit_advance(&p->port, dma->tx_size);  in __dma_tx_complete()
35 	if (ret || !dma->tx_running)  in __dma_tx_complete()
44 	struct uart_8250_dma	*dma = p->dma;  in __dma_rx_complete()  local
49 	dma->rx_running = 0;  in __dma_rx_complete()
50 	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);  in __dma_rx_complete()
52 	count = dma->rx_size - state.residue;  in __dma_rx_complete()
54 	tty_insert_flip_string(tty_port, dma->rx_buf, count);  in __dma_rx_complete()
62 	struct uart_8250_dma		*dma = p->dma;  in serial8250_tx_dma()  local
68 	if (dma->tx_running) {  in serial8250_tx_dma()
70 			dmaengine_pause(dma->txchan);  in serial8250_tx_dma()
72 			dmaengine_resume(dma->txchan);  in serial8250_tx_dma()
84 	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);  in serial8250_tx_dma()
88 	desc = dmaengine_prep_slave_single(dma->txchan,  in serial8250_tx_dma()
89 					   dma->tx_addr + xmit->tail,  in serial8250_tx_dma()
90 					   dma->tx_size, DMA_MEM_TO_DEV,  in serial8250_tx_dma()
97 	dma->tx_running = 1;  in serial8250_tx_dma()
101 	dma->tx_cookie = dmaengine_submit(desc);  in serial8250_tx_dma()
103 	dma_sync_single_for_device(dma->txchan->device->dev, dma->tx_addr,  in serial8250_tx_dma()
106 	dma_async_issue_pending(dma->txchan);  in serial8250_tx_dma()
108 	dma->tx_err = 0;  in serial8250_tx_dma()
112 	dma->tx_err = 1;  in serial8250_tx_dma()
118 	struct uart_8250_dma		*dma = p->dma;  in serial8250_rx_dma()  local
121 	if (dma->rx_running)  in serial8250_rx_dma()
126 	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,  in serial8250_rx_dma()
127 					   dma->rx_size, DMA_DEV_TO_MEM,  in serial8250_rx_dma()
132 	dma->rx_running = 1;  in serial8250_rx_dma()
136 	dma->rx_cookie = dmaengine_submit(desc);  in serial8250_rx_dma()
138 	dma_async_issue_pending(dma->rxchan);  in serial8250_rx_dma()
145 	struct uart_8250_dma *dma = p->dma;  in serial8250_rx_dma_flush()  local
147 	if (dma->rx_running) {  in serial8250_rx_dma_flush()
148 		dmaengine_pause(dma->rxchan);  in serial8250_rx_dma_flush()
150 		dmaengine_terminate_async(dma->rxchan);  in serial8250_rx_dma_flush()
157 	struct uart_8250_dma	*dma = p->dma;  in serial8250_request_dma()  local
158 	phys_addr_t rx_dma_addr = dma->rx_dma_addr ?  in serial8250_request_dma()
159 				  dma->rx_dma_addr : p->port.mapbase;  in serial8250_request_dma()
160 	phys_addr_t tx_dma_addr = dma->tx_dma_addr ?  in serial8250_request_dma()
161 				  dma->tx_dma_addr : p->port.mapbase;  in serial8250_request_dma()
167 	dma->rxconf.direction		= DMA_DEV_TO_MEM;  in serial8250_request_dma()
168 	dma->rxconf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;  in serial8250_request_dma()
169 	dma->rxconf.src_addr		= rx_dma_addr + UART_RX;  in serial8250_request_dma()
171 	dma->txconf.direction		= DMA_MEM_TO_DEV;  in serial8250_request_dma()
172 	dma->txconf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;  in serial8250_request_dma()
173 	dma->txconf.dst_addr		= tx_dma_addr + UART_TX;  in serial8250_request_dma()
179 	dma->rxchan = dma_request_slave_channel_compat(mask,  in serial8250_request_dma()
180 						       dma->fn, dma->rx_param,  in serial8250_request_dma()
182 	if (!dma->rxchan)  in serial8250_request_dma()
185 	/* 8250 rx dma requires dmaengine driver to support pause/terminate */  in serial8250_request_dma()
186 	ret = dma_get_slave_caps(dma->rxchan, &caps);  in serial8250_request_dma()
195 	dmaengine_slave_config(dma->rxchan, &dma->rxconf);  in serial8250_request_dma()
198 	dma->txchan = dma_request_slave_channel_compat(mask,  in serial8250_request_dma()
199 						       dma->fn, dma->tx_param,  in serial8250_request_dma()
201 	if (!dma->txchan) {  in serial8250_request_dma()
206 	/* 8250 tx dma requires dmaengine driver to support terminate */  in serial8250_request_dma()
207 	ret = dma_get_slave_caps(dma->txchan, &caps);  in serial8250_request_dma()
215 	dmaengine_slave_config(dma->txchan, &dma->txconf);  in serial8250_request_dma()
218 	if (!dma->rx_size)  in serial8250_request_dma()
219 		dma->rx_size = PAGE_SIZE;  in serial8250_request_dma()
221 	dma->rx_buf = dma_alloc_coherent(dma->rxchan->device->dev, dma->rx_size,  in serial8250_request_dma()
222 					&dma->rx_addr, GFP_KERNEL);  in serial8250_request_dma()
223 	if (!dma->rx_buf) {  in serial8250_request_dma()
229 	dma->tx_addr = dma_map_single(dma->txchan->device->dev,  in serial8250_request_dma()
233 	if (dma_mapping_error(dma->txchan->device->dev, dma->tx_addr)) {  in serial8250_request_dma()
234 		dma_free_coherent(dma->rxchan->device->dev, dma->rx_size,  in serial8250_request_dma()
235 				  dma->rx_buf, dma->rx_addr);  in serial8250_request_dma()
240 	dev_dbg_ratelimited(p->port.dev, "got both dma channels\n");  in serial8250_request_dma()
244 	dma_release_channel(dma->txchan);  in serial8250_request_dma()
246 	dma_release_channel(dma->rxchan);  in serial8250_request_dma()
253 	struct uart_8250_dma *dma = p->dma;  in serial8250_release_dma()  local
255 	if (!dma)  in serial8250_release_dma()
259 	dmaengine_terminate_sync(dma->rxchan);  in serial8250_release_dma()
260 	dma_free_coherent(dma->rxchan->device->dev, dma->rx_size, dma->rx_buf,  in serial8250_release_dma()
261 			  dma->rx_addr);  in serial8250_release_dma()
262 	dma_release_channel(dma->rxchan);  in serial8250_release_dma()
263 	dma->rxchan = NULL;  in serial8250_release_dma()
266 	dmaengine_terminate_sync(dma->txchan);  in serial8250_release_dma()
267 	dma_unmap_single(dma->txchan->device->dev, dma->tx_addr,  in serial8250_release_dma()
269 	dma_release_channel(dma->txchan);  in serial8250_release_dma()
270 	dma->txchan = NULL;  in serial8250_release_dma()
271 	dma->tx_running = 0;  in serial8250_release_dma()
273 	dev_dbg_ratelimited(p->port.dev, "dma channels released\n");  in serial8250_release_dma()