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path: root/drivers/tty/serial/imx.c
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Diffstat (limited to 'drivers/tty/serial/imx.c')
-rw-r--r--drivers/tty/serial/imx.c85
1 files changed, 33 insertions, 52 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index a0ebbc9ce5cd..b2cfdb661947 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -223,8 +223,7 @@ struct imx_port {
struct dma_chan *dma_chan_rx, *dma_chan_tx;
struct scatterlist rx_sgl, tx_sgl[2];
void *rx_buf;
- unsigned int rx_bytes, tx_bytes;
- struct work_struct tsk_dma_rx, tsk_dma_tx;
+ unsigned int tx_bytes;
unsigned int dma_tx_nents;
wait_queue_head_t dma_wait;
};
@@ -505,34 +504,25 @@ static void dma_tx_callback(void *data)
dev_dbg(sport->port.dev, "exit in %s.\n", __func__);
return;
}
-
- schedule_work(&sport->tsk_dma_tx);
}
-static void dma_tx_work(struct work_struct *w)
+static void imx_dma_tx(struct imx_port *sport)
{
- struct imx_port *sport = container_of(w, struct imx_port, tsk_dma_tx);
struct circ_buf *xmit = &sport->port.state->xmit;
struct scatterlist *sgl = sport->tx_sgl;
struct dma_async_tx_descriptor *desc;
struct dma_chan *chan = sport->dma_chan_tx;
struct device *dev = sport->port.dev;
enum dma_status status;
- unsigned long flags;
int ret;
- status = chan->device->device_tx_status(chan, (dma_cookie_t)0, NULL);
+ status = dmaengine_tx_status(chan, (dma_cookie_t)0, NULL);
if (DMA_IN_PROGRESS == status)
return;
- spin_lock_irqsave(&sport->port.lock, flags);
sport->tx_bytes = uart_circ_chars_pending(xmit);
- if (sport->tx_bytes == 0) {
- spin_unlock_irqrestore(&sport->port.lock, flags);
- return;
- }
- if (xmit->tail > xmit->head) {
+ if (xmit->tail > xmit->head && xmit->head > 0) {
sport->dma_tx_nents = 2;
sg_init_table(sgl, 2);
sg_set_buf(sgl, xmit->buf + xmit->tail,
@@ -542,7 +532,6 @@ static void dma_tx_work(struct work_struct *w)
sport->dma_tx_nents = 1;
sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
}
- spin_unlock_irqrestore(&sport->port.lock, flags);
ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
if (ret == 0) {
@@ -609,11 +598,7 @@ static void imx_start_tx(struct uart_port *port)
}
if (sport->dma_is_enabled) {
- /*
- * We may in the interrupt context, so arise a work_struct to
- * do the real job.
- */
- schedule_work(&sport->tsk_dma_tx);
+ imx_dma_tx(sport);
return;
}
@@ -732,6 +717,7 @@ out:
return IRQ_HANDLED;
}
+static int start_rx_dma(struct imx_port *sport);
/*
* If the RXFIFO is filled with some data, and then we
* arise a DMA operation to receive them.
@@ -750,7 +736,7 @@ static void imx_dma_rxint(struct imx_port *sport)
writel(temp, sport->port.membase + UCR1);
/* tell the DMA to receive the data. */
- schedule_work(&sport->tsk_dma_rx);
+ start_rx_dma(sport);
}
}
@@ -795,8 +781,15 @@ static irqreturn_t imx_int(int irq, void *dev_id)
static unsigned int imx_tx_empty(struct uart_port *port)
{
struct imx_port *sport = (struct imx_port *)port;
+ unsigned int ret;
+
+ ret = (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
- return (readl(sport->port.membase + USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
+ /* If the TX DMA is working, return 0. */
+ if (sport->dma_is_enabled && sport->dma_is_txing)
+ ret = 0;
+
+ return ret;
}
/*
@@ -865,22 +858,6 @@ static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
}
#define RX_BUF_SIZE (PAGE_SIZE)
-static int start_rx_dma(struct imx_port *sport);
-static void dma_rx_work(struct work_struct *w)
-{
- struct imx_port *sport = container_of(w, struct imx_port, tsk_dma_rx);
- struct tty_port *port = &sport->port.state->port;
-
- if (sport->rx_bytes) {
- tty_insert_flip_string(port, sport->rx_buf, sport->rx_bytes);
- tty_flip_buffer_push(port);
- sport->rx_bytes = 0;
- }
-
- if (sport->dma_is_rxing)
- start_rx_dma(sport);
-}
-
static void imx_rx_dma_done(struct imx_port *sport)
{
unsigned long temp;
@@ -912,6 +889,7 @@ static void dma_rx_callback(void *data)
struct imx_port *sport = data;
struct dma_chan *chan = sport->dma_chan_rx;
struct scatterlist *sgl = &sport->rx_sgl;
+ struct tty_port *port = &sport->port.state->port;
struct dma_tx_state state;
enum dma_status status;
unsigned int count;
@@ -919,13 +897,15 @@ static void dma_rx_callback(void *data)
/* unmap it first */
dma_unmap_sg(sport->port.dev, sgl, 1, DMA_FROM_DEVICE);
- status = chan->device->device_tx_status(chan, (dma_cookie_t)0, &state);
+ status = dmaengine_tx_status(chan, (dma_cookie_t)0, &state);
count = RX_BUF_SIZE - state.residue;
dev_dbg(sport->port.dev, "We get %d bytes.\n", count);
if (count) {
- sport->rx_bytes = count;
- schedule_work(&sport->tsk_dma_rx);
+ tty_insert_flip_string(port, sport->rx_buf, count);
+ tty_flip_buffer_push(port);
+
+ start_rx_dma(sport);
} else
imx_rx_dma_done(sport);
}
@@ -1007,7 +987,6 @@ static int imx_uart_dma_init(struct imx_port *sport)
ret = -ENOMEM;
goto err;
}
- sport->rx_bytes = 0;
/* Prepare for TX : */
sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
@@ -1038,11 +1017,7 @@ err:
static void imx_enable_dma(struct imx_port *sport)
{
unsigned long temp;
- struct tty_port *port = &sport->port.state->port;
- port->low_latency = 1;
- INIT_WORK(&sport->tsk_dma_tx, dma_tx_work);
- INIT_WORK(&sport->tsk_dma_rx, dma_rx_work);
init_waitqueue_head(&sport->dma_wait);
/* set UCR1 */
@@ -1063,7 +1038,6 @@ static void imx_enable_dma(struct imx_port *sport)
static void imx_disable_dma(struct imx_port *sport)
{
unsigned long temp;
- struct tty_port *port = &sport->port.state->port;
/* clear UCR1 */
temp = readl(sport->port.membase + UCR1);
@@ -1081,7 +1055,6 @@ static void imx_disable_dma(struct imx_port *sport)
writel(temp, sport->port.membase + UCR4);
sport->dma_is_enabled = 0;
- port->low_latency = 0;
}
/* half the RX buffer size */
@@ -1303,6 +1276,16 @@ static void imx_shutdown(struct uart_port *port)
clk_disable_unprepare(sport->clk_ipg);
}
+static void imx_flush_buffer(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+
+ if (sport->dma_is_enabled) {
+ sport->tx_bytes = 0;
+ dmaengine_terminate_all(sport->dma_chan_tx);
+ }
+}
+
static void
imx_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
@@ -1539,7 +1522,7 @@ imx_verify_port(struct uart_port *port, struct serial_struct *ser)
ret = -EINVAL;
if (sport->port.uartclk / 16 != ser->baud_base)
ret = -EINVAL;
- if ((void *)sport->port.mapbase != ser->iomem_base)
+ if (sport->port.mapbase != (unsigned long)ser->iomem_base)
ret = -EINVAL;
if (sport->port.iobase != ser->port)
ret = -EINVAL;
@@ -1623,6 +1606,7 @@ static struct uart_ops imx_pops = {
.break_ctl = imx_break_ctl,
.startup = imx_startup,
.shutdown = imx_shutdown,
+ .flush_buffer = imx_flush_buffer,
.set_termios = imx_set_termios,
.type = imx_type,
.release_port = imx_release_port,
@@ -1912,9 +1896,6 @@ static int serial_imx_probe_dt(struct imx_port *sport,
sport->devdata = of_id->data;
- if (of_device_is_stdout_path(np))
- add_preferred_console(imx_reg.cons->name, sport->port.line, 0);
-
return 0;
}
#else
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.