[PATCH v5 06/11] serial: 8250_dma: adjust DMA address of the UART
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2016-05-06 15:19:07
Also in:
lkml
Subsystem:
8250/16?50 (and clone uarts) serial driver, the rest, tty layer and serial drivers · Maintainers:
Greg Kroah-Hartman, Linus Torvalds, Jiri Slaby
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> --- drivers/tty/serial/8250/8250.h | 5 +++++ drivers/tty/serial/8250/8250_dma.c | 8 ++++++-- 2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 215a992..664232b 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h@@ -31,6 +31,11 @@ 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;
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 75c4b40..2db57b0 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c@@ -149,6 +149,10 @@ void serial8250_rx_dma_flush(struct uart_8250_port *p) 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;
@@ -156,11 +160,11 @@ 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);
--
2.8.1