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serial: fsl_lpuart: add DMA support
Add dma support for lpuart. This function depend on DMA driver. You can turn on it by write both the dmas and dma-name properties in dts node. Signed-off-by: Yuan Yao <yao.yuan@freescale.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Yuan Yao
Greg Kroah-Hartman
parent
c957dd4946
commit
f1cd8c8792
@ -5,10 +5,19 @@ Required properties:
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- reg : Address and length of the register set for the device
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- interrupts : Should contain uart interrupt
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Optional properties:
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- dmas: A list of two dma specifiers, one for each entry in dma-names.
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- dma-names: should contain "tx" and "rx".
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Note: Optional properties for DMA support. Write them both or both not.
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Example:
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uart0: serial@40027000 {
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compatible = "fsl,vf610-lpuart";
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reg = <0x40027000 0x1000>;
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interrupts = <0 61 0x00>;
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};
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compatible = "fsl,vf610-lpuart";
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reg = <0x40027000 0x1000>;
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interrupts = <0 61 0x00>;
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dmas = <&edma0 0 2>,
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<&edma0 0 3>;
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dma-names = "rx","tx";
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};
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@ -13,14 +13,19 @@
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#define SUPPORT_SYSRQ
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#endif
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#include <linux/module.h>
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#include <linux/clk.h>
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#include <linux/console.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmaengine.h>
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#include <linux/dmapool.h>
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#include <linux/io.h>
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#include <linux/irq.h>
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#include <linux/clk.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/console.h>
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#include <linux/of_dma.h>
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#include <linux/serial_core.h>
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#include <linux/slab.h>
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#include <linux/tty_flip.h>
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/* All registers are 8-bit width */
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@ -112,6 +117,10 @@
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#define UARTSFIFO_TXOF 0x02
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#define UARTSFIFO_RXUF 0x01
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#define DMA_MAXBURST 16
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#define DMA_MAXBURST_MASK (DMA_MAXBURST - 1)
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#define FSL_UART_RX_DMA_BUFFER_SIZE 64
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#define DRIVER_NAME "fsl-lpuart"
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#define DEV_NAME "ttyLP"
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#define UART_NR 6
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@ -121,6 +130,24 @@ struct lpuart_port {
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struct clk *clk;
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unsigned int txfifo_size;
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unsigned int rxfifo_size;
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bool lpuart_dma_use;
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struct dma_chan *dma_tx_chan;
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struct dma_chan *dma_rx_chan;
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struct dma_async_tx_descriptor *dma_tx_desc;
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struct dma_async_tx_descriptor *dma_rx_desc;
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dma_addr_t dma_tx_buf_bus;
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dma_addr_t dma_rx_buf_bus;
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dma_cookie_t dma_tx_cookie;
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dma_cookie_t dma_rx_cookie;
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unsigned char *dma_tx_buf_virt;
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unsigned char *dma_rx_buf_virt;
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unsigned int dma_tx_bytes;
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unsigned int dma_rx_bytes;
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int dma_tx_in_progress;
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int dma_rx_in_progress;
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unsigned int dma_rx_timeout;
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struct timer_list lpuart_timer;
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};
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static struct of_device_id lpuart_dt_ids[] = {
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@ -131,6 +158,10 @@ static struct of_device_id lpuart_dt_ids[] = {
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};
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MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
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/* Forward declare this for the dma callbacks*/
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static void lpuart_dma_tx_complete(void *arg);
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static void lpuart_dma_rx_complete(void *arg);
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static void lpuart_stop_tx(struct uart_port *port)
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{
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unsigned char temp;
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@ -152,6 +183,210 @@ static void lpuart_enable_ms(struct uart_port *port)
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{
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}
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static void lpuart_copy_rx_to_tty(struct lpuart_port *sport,
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struct tty_port *tty, int count)
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{
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int copied;
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sport->port.icount.rx += count;
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if (!tty) {
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dev_err(sport->port.dev, "No tty port\n");
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return;
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}
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dma_sync_single_for_cpu(sport->port.dev, sport->dma_rx_buf_bus,
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FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
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copied = tty_insert_flip_string(tty,
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((unsigned char *)(sport->dma_rx_buf_virt)), count);
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if (copied != count) {
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WARN_ON(1);
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dev_err(sport->port.dev, "RxData copy to tty layer failed\n");
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}
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dma_sync_single_for_device(sport->port.dev, sport->dma_rx_buf_bus,
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FSL_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE);
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}
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static void lpuart_pio_tx(struct lpuart_port *sport)
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{
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struct circ_buf *xmit = &sport->port.state->xmit;
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unsigned long flags;
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spin_lock_irqsave(&sport->port.lock, flags);
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while (!uart_circ_empty(xmit) &&
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readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size) {
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writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR);
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xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
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sport->port.icount.tx++;
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}
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if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
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uart_write_wakeup(&sport->port);
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if (uart_circ_empty(xmit))
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writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_TDMAS,
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sport->port.membase + UARTCR5);
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spin_unlock_irqrestore(&sport->port.lock, flags);
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}
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static int lpuart_dma_tx(struct lpuart_port *sport, unsigned long count)
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{
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struct circ_buf *xmit = &sport->port.state->xmit;
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dma_addr_t tx_bus_addr;
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dma_sync_single_for_device(sport->port.dev, sport->dma_tx_buf_bus,
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UART_XMIT_SIZE, DMA_TO_DEVICE);
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sport->dma_tx_bytes = count & ~(DMA_MAXBURST_MASK);
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tx_bus_addr = sport->dma_tx_buf_bus + xmit->tail;
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sport->dma_tx_desc = dmaengine_prep_slave_single(sport->dma_tx_chan,
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tx_bus_addr, sport->dma_tx_bytes,
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DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
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if (!sport->dma_tx_desc) {
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dev_err(sport->port.dev, "Not able to get desc for tx\n");
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return -EIO;
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}
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sport->dma_tx_desc->callback = lpuart_dma_tx_complete;
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sport->dma_tx_desc->callback_param = sport;
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sport->dma_tx_in_progress = 1;
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sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc);
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dma_async_issue_pending(sport->dma_tx_chan);
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return 0;
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}
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static void lpuart_prepare_tx(struct lpuart_port *sport)
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{
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struct circ_buf *xmit = &sport->port.state->xmit;
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unsigned long count = CIRC_CNT_TO_END(xmit->head,
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xmit->tail, UART_XMIT_SIZE);
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if (!count)
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return;
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if (count < DMA_MAXBURST)
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writeb(readb(sport->port.membase + UARTCR5) & ~UARTCR5_TDMAS,
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sport->port.membase + UARTCR5);
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else {
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writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_TDMAS,
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sport->port.membase + UARTCR5);
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lpuart_dma_tx(sport, count);
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}
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}
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static void lpuart_dma_tx_complete(void *arg)
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{
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struct lpuart_port *sport = arg;
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struct circ_buf *xmit = &sport->port.state->xmit;
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unsigned long flags;
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async_tx_ack(sport->dma_tx_desc);
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spin_lock_irqsave(&sport->port.lock, flags);
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xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1);
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sport->dma_tx_in_progress = 0;
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if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
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uart_write_wakeup(&sport->port);
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lpuart_prepare_tx(sport);
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spin_unlock_irqrestore(&sport->port.lock, flags);
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}
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static int lpuart_dma_rx(struct lpuart_port *sport)
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{
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dma_sync_single_for_device(sport->port.dev, sport->dma_rx_buf_bus,
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FSL_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE);
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sport->dma_rx_desc = dmaengine_prep_slave_single(sport->dma_rx_chan,
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sport->dma_rx_buf_bus, FSL_UART_RX_DMA_BUFFER_SIZE,
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DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
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if (!sport->dma_rx_desc) {
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dev_err(sport->port.dev, "Not able to get desc for rx\n");
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return -EIO;
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}
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sport->dma_rx_desc->callback = lpuart_dma_rx_complete;
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sport->dma_rx_desc->callback_param = sport;
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sport->dma_rx_in_progress = 1;
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sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc);
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dma_async_issue_pending(sport->dma_rx_chan);
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return 0;
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}
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static void lpuart_dma_rx_complete(void *arg)
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{
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struct lpuart_port *sport = arg;
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struct tty_port *port = &sport->port.state->port;
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unsigned long flags;
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async_tx_ack(sport->dma_rx_desc);
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spin_lock_irqsave(&sport->port.lock, flags);
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sport->dma_rx_in_progress = 0;
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lpuart_copy_rx_to_tty(sport, port, FSL_UART_RX_DMA_BUFFER_SIZE);
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tty_flip_buffer_push(port);
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lpuart_dma_rx(sport);
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spin_unlock_irqrestore(&sport->port.lock, flags);
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}
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static void lpuart_timer_func(unsigned long data)
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{
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struct lpuart_port *sport = (struct lpuart_port *)data;
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struct tty_port *port = &sport->port.state->port;
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struct dma_tx_state state;
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unsigned long flags;
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unsigned char temp;
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int count;
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del_timer(&sport->lpuart_timer);
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dmaengine_pause(sport->dma_rx_chan);
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dmaengine_tx_status(sport->dma_rx_chan, sport->dma_rx_cookie, &state);
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dmaengine_terminate_all(sport->dma_rx_chan);
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count = FSL_UART_RX_DMA_BUFFER_SIZE - state.residue;
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async_tx_ack(sport->dma_rx_desc);
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spin_lock_irqsave(&sport->port.lock, flags);
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sport->dma_rx_in_progress = 0;
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lpuart_copy_rx_to_tty(sport, port, count);
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tty_flip_buffer_push(port);
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temp = readb(sport->port.membase + UARTCR5);
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writeb(temp & ~UARTCR5_RDMAS, sport->port.membase + UARTCR5);
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spin_unlock_irqrestore(&sport->port.lock, flags);
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}
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static inline void lpuart_prepare_rx(struct lpuart_port *sport)
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{
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unsigned long flags;
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unsigned char temp;
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spin_lock_irqsave(&sport->port.lock, flags);
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init_timer(&sport->lpuart_timer);
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sport->lpuart_timer.function = lpuart_timer_func;
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sport->lpuart_timer.data = (unsigned long)sport;
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sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
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add_timer(&sport->lpuart_timer);
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lpuart_dma_rx(sport);
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temp = readb(sport->port.membase + UARTCR5);
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writeb(temp | UARTCR5_RDMAS, sport->port.membase + UARTCR5);
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spin_unlock_irqrestore(&sport->port.lock, flags);
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}
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static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
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{
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struct circ_buf *xmit = &sport->port.state->xmit;
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@ -172,14 +407,21 @@ static inline void lpuart_transmit_buffer(struct lpuart_port *sport)
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static void lpuart_start_tx(struct uart_port *port)
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{
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struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
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struct lpuart_port *sport = container_of(port,
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struct lpuart_port, port);
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struct circ_buf *xmit = &sport->port.state->xmit;
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unsigned char temp;
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temp = readb(port->membase + UARTCR2);
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writeb(temp | UARTCR2_TIE, port->membase + UARTCR2);
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if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
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lpuart_transmit_buffer(sport);
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if (sport->lpuart_dma_use) {
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if (!uart_circ_empty(xmit) && !sport->dma_tx_in_progress)
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lpuart_prepare_tx(sport);
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} else {
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if (readb(port->membase + UARTSR1) & UARTSR1_TDRE)
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lpuart_transmit_buffer(sport);
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}
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}
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static irqreturn_t lpuart_txint(int irq, void *dev_id)
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@ -279,12 +521,19 @@ static irqreturn_t lpuart_int(int irq, void *dev_id)
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sts = readb(sport->port.membase + UARTSR1);
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if (sts & UARTSR1_RDRF)
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lpuart_rxint(irq, dev_id);
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if (sts & UARTSR1_RDRF) {
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if (sport->lpuart_dma_use)
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lpuart_prepare_rx(sport);
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else
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lpuart_rxint(irq, dev_id);
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}
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if (sts & UARTSR1_TDRE &&
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!(readb(sport->port.membase + UARTCR5) & UARTCR5_TDMAS))
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lpuart_txint(irq, dev_id);
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!(readb(sport->port.membase + UARTCR5) & UARTCR5_TDMAS)) {
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if (sport->lpuart_dma_use)
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lpuart_pio_tx(sport);
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else
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lpuart_txint(irq, dev_id);
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}
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return IRQ_HANDLED;
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}
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@ -366,13 +615,156 @@ static void lpuart_setup_watermark(struct lpuart_port *sport)
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writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH,
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sport->port.membase + UARTCFIFO);
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writeb(2, sport->port.membase + UARTTWFIFO);
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writeb(0, sport->port.membase + UARTTWFIFO);
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writeb(1, sport->port.membase + UARTRWFIFO);
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/* Restore cr2 */
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writeb(cr2_saved, sport->port.membase + UARTCR2);
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}
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static int lpuart_dma_tx_request(struct uart_port *port)
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{
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struct lpuart_port *sport = container_of(port,
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struct lpuart_port, port);
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struct dma_chan *tx_chan;
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struct dma_slave_config dma_tx_sconfig;
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dma_addr_t dma_bus;
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unsigned char *dma_buf;
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int ret;
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tx_chan = dma_request_slave_channel(sport->port.dev, "tx");
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if (!tx_chan) {
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dev_err(sport->port.dev, "Dma tx channel request failed!\n");
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return -ENODEV;
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}
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dma_bus = dma_map_single(tx_chan->device->dev,
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sport->port.state->xmit.buf,
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UART_XMIT_SIZE, DMA_TO_DEVICE);
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if (dma_mapping_error(tx_chan->device->dev, dma_bus)) {
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dev_err(sport->port.dev, "dma_map_single tx failed\n");
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dma_release_channel(tx_chan);
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return -ENOMEM;
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}
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dma_buf = sport->port.state->xmit.buf;
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dma_tx_sconfig.dst_addr = sport->port.mapbase + UARTDR;
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dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
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dma_tx_sconfig.dst_maxburst = DMA_MAXBURST;
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dma_tx_sconfig.direction = DMA_MEM_TO_DEV;
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ret = dmaengine_slave_config(tx_chan, &dma_tx_sconfig);
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if (ret < 0) {
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dev_err(sport->port.dev,
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"Dma slave config failed, err = %d\n", ret);
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dma_release_channel(tx_chan);
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return ret;
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}
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sport->dma_tx_chan = tx_chan;
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sport->dma_tx_buf_virt = dma_buf;
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sport->dma_tx_buf_bus = dma_bus;
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sport->dma_tx_in_progress = 0;
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return 0;
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}
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static int lpuart_dma_rx_request(struct uart_port *port)
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{
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struct lpuart_port *sport = container_of(port,
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struct lpuart_port, port);
|
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struct dma_chan *rx_chan;
|
||||
struct dma_slave_config dma_rx_sconfig;
|
||||
dma_addr_t dma_bus;
|
||||
unsigned char *dma_buf;
|
||||
int ret;
|
||||
|
||||
rx_chan = dma_request_slave_channel(sport->port.dev, "rx");
|
||||
|
||||
if (!rx_chan) {
|
||||
dev_err(sport->port.dev, "Dma rx channel request failed!\n");
|
||||
return -ENODEV;
|
||||
}
|
||||
|
||||
dma_buf = devm_kzalloc(sport->port.dev,
|
||||
FSL_UART_RX_DMA_BUFFER_SIZE, GFP_KERNEL);
|
||||
|
||||
if (!dma_buf) {
|
||||
dev_err(sport->port.dev, "Dma rx alloc failed\n");
|
||||
dma_release_channel(rx_chan);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
dma_bus = dma_map_single(rx_chan->device->dev, dma_buf,
|
||||
FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
|
||||
|
||||
if (dma_mapping_error(rx_chan->device->dev, dma_bus)) {
|
||||
dev_err(sport->port.dev, "dma_map_single rx failed\n");
|
||||
dma_release_channel(rx_chan);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
dma_rx_sconfig.src_addr = sport->port.mapbase + UARTDR;
|
||||
dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
|
||||
dma_rx_sconfig.src_maxburst = 1;
|
||||
dma_rx_sconfig.direction = DMA_DEV_TO_MEM;
|
||||
ret = dmaengine_slave_config(rx_chan, &dma_rx_sconfig);
|
||||
|
||||
if (ret < 0) {
|
||||
dev_err(sport->port.dev,
|
||||
"Dma slave config failed, err = %d\n", ret);
|
||||
dma_release_channel(rx_chan);
|
||||
return ret;
|
||||
}
|
||||
|
||||
sport->dma_rx_chan = rx_chan;
|
||||
sport->dma_rx_buf_virt = dma_buf;
|
||||
sport->dma_rx_buf_bus = dma_bus;
|
||||
sport->dma_rx_in_progress = 0;
|
||||
|
||||
sport->dma_rx_timeout = (sport->port.timeout - HZ / 50) *
|
||||
FSL_UART_RX_DMA_BUFFER_SIZE * 3 /
|
||||
sport->rxfifo_size / 2;
|
||||
|
||||
if (sport->dma_rx_timeout < msecs_to_jiffies(20))
|
||||
sport->dma_rx_timeout = msecs_to_jiffies(20);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void lpuart_dma_tx_free(struct uart_port *port)
|
||||
{
|
||||
struct lpuart_port *sport = container_of(port,
|
||||
struct lpuart_port, port);
|
||||
struct dma_chan *dma_chan;
|
||||
|
||||
dma_unmap_single(sport->port.dev, sport->dma_tx_buf_bus,
|
||||
UART_XMIT_SIZE, DMA_TO_DEVICE);
|
||||
dma_chan = sport->dma_tx_chan;
|
||||
sport->dma_tx_chan = NULL;
|
||||
sport->dma_tx_buf_bus = 0;
|
||||
sport->dma_tx_buf_virt = NULL;
|
||||
dma_release_channel(dma_chan);
|
||||
}
|
||||
|
||||
static void lpuart_dma_rx_free(struct uart_port *port)
|
||||
{
|
||||
struct lpuart_port *sport = container_of(port,
|
||||
struct lpuart_port, port);
|
||||
struct dma_chan *dma_chan;
|
||||
|
||||
dma_unmap_single(sport->port.dev, sport->dma_rx_buf_bus,
|
||||
FSL_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
|
||||
|
||||
dma_chan = sport->dma_rx_chan;
|
||||
sport->dma_rx_chan = NULL;
|
||||
sport->dma_rx_buf_bus = 0;
|
||||
sport->dma_rx_buf_virt = NULL;
|
||||
dma_release_channel(dma_chan);
|
||||
}
|
||||
|
||||
static int lpuart_startup(struct uart_port *port)
|
||||
{
|
||||
struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
|
||||
@ -380,6 +772,15 @@ static int lpuart_startup(struct uart_port *port)
|
||||
unsigned long flags;
|
||||
unsigned char temp;
|
||||
|
||||
/*whether use dma support by dma request results*/
|
||||
if (lpuart_dma_tx_request(port) || lpuart_dma_rx_request(port)) {
|
||||
sport->lpuart_dma_use = false;
|
||||
} else {
|
||||
sport->lpuart_dma_use = true;
|
||||
temp = readb(port->membase + UARTCR5);
|
||||
writeb(temp | UARTCR5_TDMAS, port->membase + UARTCR5);
|
||||
}
|
||||
|
||||
ret = devm_request_irq(port->dev, port->irq, lpuart_int, 0,
|
||||
DRIVER_NAME, sport);
|
||||
if (ret)
|
||||
@ -414,6 +815,11 @@ static void lpuart_shutdown(struct uart_port *port)
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
|
||||
devm_free_irq(port->dev, port->irq, sport);
|
||||
|
||||
if (sport->lpuart_dma_use) {
|
||||
lpuart_dma_tx_free(port);
|
||||
lpuart_dma_rx_free(port);
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
|
||||
Loading…
Reference in New Issue
Block a user