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Commit a930e528 authored by Elen Song's avatar Elen Song Committed by Greg Kroah-Hartman
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serial: at91: use function pointer to choose pdc or pio 



use function pointer can avoid define atmel_use_pdc_tx/rx everywhere.
(*prepare_rx/tx)() is in setup transfer stage.
(*schedule_rx/tx)() is in tasklet schedule stage.
(*release_rx/tx)() is used when shutdown the transfer.

Signed-off-by: default avatarElen Song <elen.song@atmel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 64e22ebe

drivers/tty/serial/atmel_serial.c

+130 −73
Original line number Diff line number Diff line
@@ -154,6 +154,12 @@ struct atmel_uart_port { 


	struct serial_rs485	rs485;		/* rs485 settings */

	unsigned int		tx_done_mask;

	int (*prepare_rx)(struct uart_port *port);

	int (*prepare_tx)(struct uart_port *port);

	void (*schedule_rx)(struct uart_port *port);

	void (*schedule_tx)(struct uart_port *port);

	void (*release_rx)(struct uart_port *port);

	void (*release_tx)(struct uart_port *port);

};



static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
@@ -657,6 +663,17 @@ static irqreturn_t atmel_interrupt(int irq, void *dev_id) 
	return pass_counter ? IRQ_HANDLED : IRQ_NONE;

}



static void atmel_release_tx_pdc(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;



	dma_unmap_single(port->dev,

			 pdc->dma_addr,

			 pdc->dma_size,

			 DMA_TO_DEVICE);

}



/*

 * Called from tasklet with ENDTX and TXBUFE interrupts disabled.

 */
@@ -709,6 +726,23 @@ static void atmel_tx_pdc(struct uart_port *port) 
		uart_write_wakeup(port);

}



static int atmel_prepare_tx_pdc(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;

	struct circ_buf *xmit = &port->state->xmit;



	pdc->buf = xmit->buf;

	pdc->dma_addr = dma_map_single(port->dev,

					pdc->buf,

					UART_XMIT_SIZE,

					DMA_TO_DEVICE);

	pdc->dma_size = UART_XMIT_SIZE;

	pdc->ofs = 0;



	return 0;

}



static void atmel_rx_from_ring(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
@@ -777,6 +811,22 @@ static void atmel_rx_from_ring(struct uart_port *port) 
	spin_lock(&port->lock);

}



static void atmel_release_rx_pdc(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	int i;



	for (i = 0; i < 2; i++) {

		struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];



		dma_unmap_single(port->dev,

				 pdc->dma_addr,

				 pdc->dma_size,

				 DMA_FROM_DEVICE);

		kfree(pdc->buf);

	}

}



static void atmel_rx_from_pdc(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
@@ -854,6 +904,45 @@ static void atmel_rx_from_pdc(struct uart_port *port) 
	UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT);

}



static int atmel_prepare_rx_pdc(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);

	int i;



	for (i = 0; i < 2; i++) {

		struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];



		pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);

		if (pdc->buf == NULL) {

			if (i != 0) {

				dma_unmap_single(port->dev,

					atmel_port->pdc_rx[0].dma_addr,

					PDC_BUFFER_SIZE,

					DMA_FROM_DEVICE);

				kfree(atmel_port->pdc_rx[0].buf);

			}

			atmel_port->use_pdc_rx = 0;

			return -ENOMEM;

		}

		pdc->dma_addr = dma_map_single(port->dev,

						pdc->buf,

						PDC_BUFFER_SIZE,

						DMA_FROM_DEVICE);

		pdc->dma_size = PDC_BUFFER_SIZE;

		pdc->ofs = 0;

	}



	atmel_port->pdc_rx_idx = 0;



	UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);

	UART_PUT_RCR(port, PDC_BUFFER_SIZE);



	UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);

	UART_PUT_RNCR(port, PDC_BUFFER_SIZE);



	return 0;

}



/*

 * tasklet handling tty stuff outside the interrupt handler.

 */
@@ -867,10 +956,7 @@ static void atmel_tasklet_func(unsigned long data) 
	/* The interrupt handler does not take the lock */

	spin_lock(&port->lock);



	if (atmel_use_pdc_tx(port))

		atmel_tx_pdc(port);

	else

		atmel_tx_chars(port);

	atmel_port->schedule_tx(port);



	status = atmel_port->irq_status;

	status_change = status ^ atmel_port->irq_status_prev;
@@ -892,14 +978,36 @@ static void atmel_tasklet_func(unsigned long data) 
		atmel_port->irq_status_prev = status;

	}



	if (atmel_use_pdc_rx(port))

		atmel_rx_from_pdc(port);

	else

		atmel_rx_from_ring(port);

	atmel_port->schedule_rx(port);



	spin_unlock(&port->lock);

}



static void atmel_set_ops(struct uart_port *port)

{

	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);



	if (atmel_use_pdc_rx(port)) {

		atmel_port->prepare_rx = &atmel_prepare_rx_pdc;

		atmel_port->schedule_rx = &atmel_rx_from_pdc;

		atmel_port->release_rx = &atmel_release_rx_pdc;

	} else {

		atmel_port->prepare_rx = NULL;

		atmel_port->schedule_rx = &atmel_rx_from_ring;

		atmel_port->release_rx = NULL;

	}



	if (atmel_use_pdc_tx(port)) {

		atmel_port->prepare_tx = &atmel_prepare_tx_pdc;

		atmel_port->schedule_tx = &atmel_tx_pdc;

		atmel_port->release_tx = &atmel_release_tx_pdc;

	} else {

		atmel_port->prepare_tx = NULL;

		atmel_port->schedule_tx = &atmel_tx_chars;

		atmel_port->release_tx = NULL;

	}

}



/*

 * Perform initialization and enable port for reception

 */
@@ -929,53 +1037,17 @@ static int atmel_startup(struct uart_port *port) 
	/*

	 * Initialize DMA (if necessary)

	 */

	if (atmel_use_pdc_rx(port)) {

		int i;



		for (i = 0; i < 2; i++) {

			struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];



			pdc->buf = kmalloc(PDC_BUFFER_SIZE, GFP_KERNEL);

			if (pdc->buf == NULL) {

				if (i != 0) {

					dma_unmap_single(port->dev,

						atmel_port->pdc_rx[0].dma_addr,

						PDC_BUFFER_SIZE,

						DMA_FROM_DEVICE);

					kfree(atmel_port->pdc_rx[0].buf);

				}

				free_irq(port->irq, port);

				return -ENOMEM;

			}

			pdc->dma_addr = dma_map_single(port->dev,

						       pdc->buf,

						       PDC_BUFFER_SIZE,

						       DMA_FROM_DEVICE);

			pdc->dma_size = PDC_BUFFER_SIZE;

			pdc->ofs = 0;

		}



		atmel_port->pdc_rx_idx = 0;



		UART_PUT_RPR(port, atmel_port->pdc_rx[0].dma_addr);

		UART_PUT_RCR(port, PDC_BUFFER_SIZE);



		UART_PUT_RNPR(port, atmel_port->pdc_rx[1].dma_addr);

		UART_PUT_RNCR(port, PDC_BUFFER_SIZE);

	if (atmel_port->prepare_rx) {

		retval = atmel_port->prepare_rx(port);

		if (retval < 0)

			atmel_set_ops(port);

	}

	if (atmel_use_pdc_tx(port)) {

		struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;

		struct circ_buf *xmit = &port->state->xmit;



		pdc->buf = xmit->buf;

		pdc->dma_addr = dma_map_single(port->dev,

					       pdc->buf,

					       UART_XMIT_SIZE,

					       DMA_TO_DEVICE);

		pdc->dma_size = UART_XMIT_SIZE;

		pdc->ofs = 0;

	if (atmel_port->prepare_tx) {

		retval = atmel_port->prepare_tx(port);

		if (retval < 0)

			atmel_set_ops(port);

	}



	/*

	 * If there is a specific "open" function (to register

	 * control line interrupts)
@@ -1030,27 +1102,10 @@ static void atmel_shutdown(struct uart_port *port) 
	/*

	 * Shut-down the DMA.

	 */

	if (atmel_use_pdc_rx(port)) {

		int i;



		for (i = 0; i < 2; i++) {

			struct atmel_dma_buffer *pdc = &atmel_port->pdc_rx[i];



			dma_unmap_single(port->dev,

					 pdc->dma_addr,

					 pdc->dma_size,

					 DMA_FROM_DEVICE);

			kfree(pdc->buf);

		}

	}

	if (atmel_use_pdc_tx(port)) {

		struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;



		dma_unmap_single(port->dev,

				 pdc->dma_addr,

				 pdc->dma_size,

				 DMA_TO_DEVICE);

	}

	if (atmel_port->release_rx)

		atmel_port->release_rx(port);

	if (atmel_port->release_tx)

		atmel_port->release_tx(port);



	/*

	 * Disable all interrupts, port and break condition.
@@ -1473,6 +1528,8 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port, 
		atmel_port->rs485	= pdata->rs485;

	}



	atmel_set_ops(port);



	port->iotype		= UPIO_MEM;

	port->flags		= UPF_BOOT_AUTOCONF;

	port->ops		= &atmel_pops;