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path: root/drivers/tty/serial/amba-pl011.c
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Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
-rw-r--r--drivers/tty/serial/amba-pl011.c48
1 files changed, 43 insertions, 5 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 02016fcd91b8..8d94c194f090 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -246,6 +246,7 @@ static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg,
sg_set_page(&sg->sg, phys_to_page(dma_addr),
PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr));
sg_dma_address(&sg->sg) = dma_addr;
+ sg_dma_len(&sg->sg) = PL011_DMA_BUFFER_SIZE;
return 0;
}
@@ -321,10 +322,26 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *
.src_maxburst = uap->fifosize >> 2,
.device_fc = false,
};
+ struct dma_slave_caps caps;
+ /*
+ * Some DMA controllers provide information on their capabilities.
+ * If the controller does, check for suitable residue processing
+ * otherwise assime all is well.
+ */
+ if (0 == dma_get_slave_caps(chan, &caps)) {
+ if (caps.residue_granularity ==
+ DMA_RESIDUE_GRANULARITY_DESCRIPTOR) {
+ dma_release_channel(chan);
+ dev_info(uap->port.dev,
+ "RX DMA disabled - no residue processing\n");
+ return;
+ }
+ }
dmaengine_slave_config(chan, &rx_conf);
uap->dmarx.chan = chan;
+ uap->dmarx.auto_poll_rate = false;
if (plat && plat->dma_rx_poll_enable) {
/* Set poll rate if specified. */
if (plat->dma_rx_poll_rate) {
@@ -345,9 +362,24 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *
plat->dma_rx_poll_timeout;
else
uap->dmarx.poll_timeout = 3000;
- } else
- uap->dmarx.auto_poll_rate = false;
-
+ } else if (!plat && dev->of_node) {
+ uap->dmarx.auto_poll_rate = of_property_read_bool(
+ dev->of_node, "auto-poll");
+ if (uap->dmarx.auto_poll_rate) {
+ u32 x;
+
+ if (0 == of_property_read_u32(dev->of_node,
+ "poll-rate-ms", &x))
+ uap->dmarx.poll_rate = x;
+ else
+ uap->dmarx.poll_rate = 100;
+ if (0 == of_property_read_u32(dev->of_node,
+ "poll-timeout-ms", &x))
+ uap->dmarx.poll_timeout = x;
+ else
+ uap->dmarx.poll_timeout = 3000;
+ }
+ }
dev_info(uap->port.dev, "DMA channel RX %s\n",
dma_chan_name(uap->dmarx.chan));
}
@@ -501,7 +533,11 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
else {
size_t first = UART_XMIT_SIZE - xmit->tail;
- size_t second = xmit->head;
+ size_t second;
+
+ if (first > count)
+ first = count;
+ second = count - first;
memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
if (second)
@@ -988,7 +1024,7 @@ static void pl011_dma_startup(struct uart_amba_port *uap)
if (!uap->dmatx.chan)
return;
- uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL);
+ uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA);
if (!uap->dmatx.buf) {
dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
uap->port.fifosize = uap->fifosize;
@@ -1689,6 +1725,8 @@ static void pl011_shutdown(struct uart_port *port)
plat->exit();
}
+ if (uap->port.ops->flush_buffer)
+ uap->port.ops->flush_buffer(port);
}
static void