tty: serial: qcom-geni-serial: split out the FIFO tx code
qcom_geni_serial_handle_tx() is pretty big, let's move the code that
handles the actual writing of data to a separate function which makes
sense in preparation for introducing a dma variant of handle_tx().
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20221229155030.418800-10-brgl@bgdev.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index e34fe56..bd91a6a 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -704,53 +704,14 @@ static void qcom_geni_serial_start_rx(struct uart_port *uport)
writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
}
-static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
- bool active)
+static int qcom_geni_serial_send_chunk_fifo(struct uart_port *uport,
+ unsigned int chunk)
{
struct qcom_geni_serial_port *port = to_dev_port(uport);
struct circ_buf *xmit = &uport->state->xmit;
- size_t avail;
- size_t remaining;
- size_t pending;
- int i;
- u32 status;
- u32 irq_en;
- unsigned int chunk;
- int tail;
+ size_t remaining = chunk;
+ int i, tail = xmit->tail;
- status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
-
- /* Complete the current tx command before taking newly added data */
- if (active)
- pending = port->tx_remaining;
- else
- pending = uart_circ_chars_pending(xmit);
-
- /* All data has been transmitted and acknowledged as received */
- if (!pending && !status && done) {
- qcom_geni_serial_stop_tx(uport);
- goto out_write_wakeup;
- }
-
- avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
- avail *= BYTES_PER_FIFO_WORD;
-
- tail = xmit->tail;
- chunk = min(avail, pending);
- if (!chunk)
- goto out_write_wakeup;
-
- if (!port->tx_remaining) {
- qcom_geni_serial_setup_tx(uport, pending);
- port->tx_remaining = pending;
-
- irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
- if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
- writel(irq_en | M_TX_FIFO_WATERMARK_EN,
- uport->membase + SE_GENI_M_IRQ_EN);
- }
-
- remaining = chunk;
for (i = 0; i < chunk; ) {
unsigned int tx_bytes;
u8 buf[sizeof(u32)];
@@ -772,7 +733,52 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
port->tx_remaining -= tx_bytes;
}
- xmit->tail = tail;
+ return tail;
+}
+
+static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
+ bool active)
+{
+ struct qcom_geni_serial_port *port = to_dev_port(uport);
+ struct circ_buf *xmit = &uport->state->xmit;
+ size_t avail;
+ size_t pending;
+ u32 status;
+ u32 irq_en;
+ unsigned int chunk;
+
+ status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
+
+ /* Complete the current tx command before taking newly added data */
+ if (active)
+ pending = port->tx_remaining;
+ else
+ pending = uart_circ_chars_pending(xmit);
+
+ /* All data has been transmitted and acknowledged as received */
+ if (!pending && !status && done) {
+ qcom_geni_serial_stop_tx(uport);
+ goto out_write_wakeup;
+ }
+
+ avail = port->tx_fifo_depth - (status & TX_FIFO_WC);
+ avail *= BYTES_PER_FIFO_WORD;
+
+ chunk = min(avail, pending);
+ if (!chunk)
+ goto out_write_wakeup;
+
+ if (!port->tx_remaining) {
+ qcom_geni_serial_setup_tx(uport, pending);
+ port->tx_remaining = pending;
+
+ irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+ if (!(irq_en & M_TX_FIFO_WATERMARK_EN))
+ writel(irq_en | M_TX_FIFO_WATERMARK_EN,
+ uport->membase + SE_GENI_M_IRQ_EN);
+ }
+
+ xmit->tail = qcom_geni_serial_send_chunk_fifo(uport, chunk);
/*
* The tx fifo watermark is level triggered and latched. Though we had
