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path: root/drivers/tty/serial/amba-pl011.c
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-rw-r--r--drivers/tty/serial/amba-pl011.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 6800f5f26241..3d569cd68f58 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -51,6 +51,7 @@
#include <linux/dma-mapping.h>
#include <linux/scatterlist.h>
#include <linux/delay.h>
+#include <linux/types.h>
#include <asm/io.h>
#include <asm/sizes.h>
@@ -271,6 +272,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
.direction = DMA_MEM_TO_DEV,
.dst_maxburst = uap->fifosize >> 1,
+ .device_fc = false,
};
struct dma_chan *chan;
dma_cap_mask_t mask;
@@ -304,6 +306,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
.direction = DMA_DEV_TO_MEM,
.src_maxburst = uap->fifosize >> 1,
+ .device_fc = false,
};
chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
@@ -481,7 +484,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap)
return -EBUSY;
}
- desc = dma_dev->device_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV,
+ desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE);
@@ -664,7 +667,6 @@ static void pl011_dma_rx_callback(void *data);
static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
{
struct dma_chan *rxchan = uap->dmarx.chan;
- struct dma_device *dma_dev;
struct pl011_dmarx_data *dmarx = &uap->dmarx;
struct dma_async_tx_descriptor *desc;
struct pl011_sgbuf *sgbuf;
@@ -675,8 +677,7 @@ static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
/* Start the RX DMA job */
sgbuf = uap->dmarx.use_buf_b ?
&uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a;
- dma_dev = rxchan->device;
- desc = rxchan->device->device_prep_slave_sg(rxchan, &sgbuf->sg, 1,
+ desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
/*
@@ -827,7 +828,12 @@ static void pl011_dma_rx_callback(void *data)
{
struct uart_amba_port *uap = data;
struct pl011_dmarx_data *dmarx = &uap->dmarx;
+ struct dma_chan *rxchan = dmarx->chan;
bool lastbuf = dmarx->use_buf_b;
+ struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ?
+ &dmarx->sgbuf_b : &dmarx->sgbuf_a;
+ size_t pending;
+ struct dma_tx_state state;
int ret;
/*
@@ -838,11 +844,21 @@ static void pl011_dma_rx_callback(void *data)
* we immediately trigger the next DMA job.
*/
spin_lock_irq(&uap->port.lock);
+ /*
+ * Rx data can be taken by the UART interrupts during
+ * the DMA irq handler. So we check the residue here.
+ */
+ rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
+ pending = sgbuf->sg.length - state.residue;
+ BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
+ /* Then we terminate the transfer - we now know our residue */
+ dmaengine_terminate_all(rxchan);
+
uap->dmarx.running = false;
dmarx->use_buf_b = !lastbuf;
ret = pl011_dma_rx_trigger_dma(uap);
- pl011_dma_rx_chars(uap, PL011_DMA_BUFFER_SIZE, lastbuf, false);
+ pl011_dma_rx_chars(uap, pending, lastbuf, false);
spin_unlock_irq(&uap->port.lock);
/*
* Do this check after we picked the DMA chars so we don't
@@ -1381,6 +1397,10 @@ static int pl011_startup(struct uart_port *port)
uap->port.uartclk = clk_get_rate(uap->clk);
+ /* Clear pending error and receive interrupts */
+ writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS |
+ UART011_RTIS | UART011_RXIS, uap->port.membase + UART011_ICR);
+
/*
* Allocate the IRQ
*/
@@ -1417,10 +1437,6 @@ static int pl011_startup(struct uart_port *port)
cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE;
writew(cr, uap->port.membase + UART011_CR);
- /* Clear pending error interrupts */
- writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS,
- uap->port.membase + UART011_ICR);
-
/*
* initialise the old status of the modem signals
*/
@@ -1435,6 +1451,9 @@ static int pl011_startup(struct uart_port *port)
* as well.
*/
spin_lock_irq(&uap->port.lock);
+ /* Clear out any spuriously appearing RX interrupts */
+ writew(UART011_RTIS | UART011_RXIS,
+ uap->port.membase + UART011_ICR);
uap->im = UART011_RTIM;
if (!pl011_dma_rx_running(uap))
uap->im |= UART011_RXIM;
@@ -1944,6 +1963,10 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
uap->port.line = i;
pl011_dma_probe(uap);
+ /* Ensure interrupts from this UART are masked and cleared */
+ writew(0, uap->port.membase + UART011_IMSC);
+ writew(0xffff, uap->port.membase + UART011_ICR);
+
snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
amba_ports[i] = uap;