[PATCH v6 10/14] tty: serial: qcom-geni-serial: refactor qcom_geni_serial_send_chunk_fifo()

From: Bartosz Golaszewski
Date: Thu Dec 29 2022 - 10:51:59 EST


From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Shuffle the code a bit, drop unneeded variables, make types of others
more consistent and use uart_xmit_advance() instead of handling
tail->xmit manually.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
drivers/tty/serial/qcom_geni_serial.c | 28 ++++++++++-----------------
1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index bd91a6a5ad37..3705c0f893a4 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -93,7 +93,7 @@
#define IO_MACRO_IO2_IO3_SWAP 0x4640

/* We always configure 4 bytes per FIFO word */
-#define BYTES_PER_FIFO_WORD 4
+#define BYTES_PER_FIFO_WORD 4U

struct qcom_geni_private_data {
/* NOTE: earlycon port will have NULL here */
@@ -704,36 +704,28 @@ static void qcom_geni_serial_start_rx(struct uart_port *uport)
writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN);
}

-static int qcom_geni_serial_send_chunk_fifo(struct uart_port *uport,
- unsigned int chunk)
+static void 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 remaining = chunk;
- int i, tail = xmit->tail;
-
- for (i = 0; i < chunk; ) {
- unsigned int tx_bytes;
- u8 buf[sizeof(u32)];
- int c;
+ unsigned int tx_bytes, c, remaining = chunk;
+ u8 buf[BYTES_PER_FIFO_WORD];

+ while (remaining) {
memset(buf, 0, sizeof(buf));
- tx_bytes = min_t(size_t, remaining, BYTES_PER_FIFO_WORD);
+ tx_bytes = min(remaining, BYTES_PER_FIFO_WORD);

for (c = 0; c < tx_bytes ; c++) {
- buf[c] = xmit->buf[tail++];
- tail &= UART_XMIT_SIZE - 1;
+ buf[c] = xmit->buf[xmit->tail];
+ uart_xmit_advance(uport, 1);
}

iowrite32_rep(uport->membase + SE_GENI_TX_FIFOn, buf, 1);

- i += tx_bytes;
- uport->icount.tx += tx_bytes;
remaining -= tx_bytes;
port->tx_remaining -= tx_bytes;
}
-
- return tail;
}

static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
@@ -778,7 +770,7 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done,
uport->membase + SE_GENI_M_IRQ_EN);
}

- xmit->tail = qcom_geni_serial_send_chunk_fifo(uport, chunk);
+ qcom_geni_serial_send_chunk_fifo(uport, chunk);

/*
* The tx fifo watermark is level triggered and latched. Though we had
--
2.37.2