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serial: 8250_dma: adjust DMA address of the UART 

Some UARTs, e.g. one is used in Intel Quark, have a different address base for
DMA operations. Introduce an additional field (per RX and TX DMA channels) in
struct uart_8250_dma to cover those cases.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andy Shevchenko 2016-08-17 19:20:25 +03:00 committed by Greg Kroah-Hartman
parent 8d17047207
commit d1834babe4
2 changed files with 11 additions and 2 deletions
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5
drivers/tty/serial/8250/8250.h
View File

@ -33,6 +33,11 @@ struct uart_8250_dma {
struct dma_chan *rxchan;
struct dma_chan *txchan;
/* Device address base for DMA operations */
phys_addr_t rx_dma_addr;
phys_addr_t tx_dma_addr;
/* DMA address of the buffer in memory */
dma_addr_t rx_addr;
dma_addr_t tx_addr;

8
drivers/tty/serial/8250/8250_dma.c
View File

@ -150,6 +150,10 @@ EXPORT_SYMBOL_GPL(serial8250_rx_dma_flush);
int serial8250_request_dma(struct uart_8250_port *p)
{
struct uart_8250_dma *dma = p->dma;
phys_addr_t rx_dma_addr = dma->rx_dma_addr ?
dma->rx_dma_addr : p->port.mapbase;
phys_addr_t tx_dma_addr = dma->tx_dma_addr ?
dma->tx_dma_addr : p->port.mapbase;
dma_cap_mask_t mask;
struct dma_slave_caps caps;
int ret;
@ -157,11 +161,11 @@ int serial8250_request_dma(struct uart_8250_port *p)
/* Default slave configuration parameters */
dma->rxconf.direction = DMA_DEV_TO_MEM;
dma->rxconf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma->rxconf.src_addr = p->port.mapbase + UART_RX;
dma->rxconf.src_addr = rx_dma_addr + UART_RX;
dma->txconf.direction = DMA_MEM_TO_DEV;
dma->txconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma->txconf.dst_addr = p->port.mapbase + UART_TX;
dma->txconf.dst_addr = tx_dma_addr + UART_TX;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);