[PATCH v1 07/12] serial: 8250_dma: adjust DMA address of the UART

[Andy Shevchenko]

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

Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
---
 drivers/tty/serial/8250/8250.h     | 2 ++
 drivers/tty/serial/8250/8250_dma.c | 5 +++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 047a7ba..040deb2 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -31,6 +31,8 @@ struct uart_8250_dma {
        struct dma_chan         *rxchan;
        struct dma_chan         *txchan;
 
+       phys_addr_t             dma_addr;
+
        dma_addr_t              rx_addr;
        dma_addr_t              tx_addr;
 
diff --git a/drivers/tty/serial/8250/8250_dma.c 
b/drivers/tty/serial/8250/8250_dma.c
index b134bec..a314492 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -164,16 +164,17 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned 
int iir)
 int serial8250_request_dma(struct uart_8250_port *p)
 {
        struct uart_8250_dma    *dma = p->dma;
+       phys_addr_t dma_addr = dma->dma_addr ? dma->dma_addr : p->port.mapbase;
        dma_cap_mask_t          mask;
 
        /* 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            = 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            = dma_addr + UART_TX;
 
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
-- 
2.8.0.rc3