Commit d420fb49 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski Committed by Greg Kroah-Hartman
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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: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20221229155030.418800-10-brgl@bgdev.pl


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3931b8fd

drivers/tty/serial/qcom_geni_serial.c

+33 −27
Original line number Diff line number Diff line
@@ -704,19 +704,48 @@ 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)

{

	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;



		memset(buf, 0, sizeof(buf));

		tx_bytes = min_t(size_t, remaining, BYTES_PER_FIFO_WORD);



		for (c = 0; c < tx_bytes ; c++) {

			buf[c] = xmit->buf[tail++];

			tail &= UART_XMIT_SIZE - 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,

		bool active)

{

	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;



	status = readl(uport->membase + SE_GENI_TX_FIFO_STATUS);
@@ -735,7 +764,6 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done, 
	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;
@@ -750,29 +778,7 @@ static void qcom_geni_serial_handle_tx(struct uart_port *uport, bool done, 
					uport->membase + SE_GENI_M_IRQ_EN);

	}



	remaining = chunk;

	for (i = 0; i < chunk; ) {

		unsigned int tx_bytes;

		u8 buf[sizeof(u32)];

		int c;



		memset(buf, 0, sizeof(buf));

		tx_bytes = min_t(size_t, remaining, BYTES_PER_FIFO_WORD);



		for (c = 0; c < tx_bytes ; c++) {

			buf[c] = xmit->buf[tail++];

			tail &= UART_XMIT_SIZE - 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;

	}



	xmit->tail = tail;

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



	/*

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