Merge tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty and serial driver changes for 6.6-rc1.

  Lots of cleanups in here this cycle, and some driver updates. Short
  summary is:

   - Jiri's continued work to make the tty code and apis be a bit more
     sane with regards to modern kernel coding style and types

   - cpm_uart driver updates

   - n_gsm updates and fixes

   - meson driver updates

   - sc16is7xx driver updates

   - 8250 driver updates for different hardware types

   - qcom-geni driver fixes

   - tegra serial driver change

   - stm32 driver updates

   - synclink_gt driver cleanups

   - tty structure size reduction

  All of these have been in linux-next this week with no reported
  issues. The last bit of cleanups from Jiri and the tty structure size
  reduction came in last week, a bit late but as they were just style
  changes and size reductions, I figured they should get into this merge
  cycle so that others can work on top of them with no merge conflicts"

* tag 'tty-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (199 commits)
  tty: shrink the size of struct tty_struct by 40 bytes
  tty: n_tty: deduplicate copy code in n_tty_receive_buf_real_raw()
  tty: n_tty: extract ECHO_OP processing to a separate function
  tty: n_tty: unify counts to size_t
  tty: n_tty: use u8 for chars and flags
  tty: n_tty: simplify chars_in_buffer()
  tty: n_tty: remove unsigned char casts from character constants
  tty: n_tty: move newline handling to a separate function
  tty: n_tty: move canon handling to a separate function
  tty: n_tty: use MASK() for masking out size bits
  tty: n_tty: make n_tty_data::num_overrun unsigned
  tty: n_tty: use time_is_before_jiffies() in n_tty_receive_overrun()
  tty: n_tty: use 'num' for writes' counts
  tty: n_tty: use output character directly
  tty: n_tty: make flow of n_tty_receive_buf_common() a bool
  Revert "tty: serial: meson: Add a earlycon for the T7 SoC"
  Documentation: devices.txt: Fix minors for ttyCPM*
  Documentation: devices.txt: Remove ttySIOC*
  Documentation: devices.txt: Remove ttyIOC*
  serial: 8250_bcm7271: improve bcm7271 8250 port
  ...

1 files changed, 63 insertions, 25 deletions

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index c569a08b5b19..f72e1340b47d 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -18,9 +18,9 @@
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/serial_core.h>
 #include <linux/slab.h>
@@ -288,6 +288,7 @@ struct lpuart_port {
 	wait_queue_head_t	dma_wait;
 	bool			is_cs7; /* Set to true when character size is 7 */
 					/* and the parity is enabled		*/
+	bool			dma_idle_int;
 };
 
 struct lpuart_soc_data {
@@ -1064,26 +1065,6 @@ static irqreturn_t lpuart_int(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t lpuart32_int(int irq, void *dev_id)
-{
-	struct lpuart_port *sport = dev_id;
-	unsigned long sts, rxcount;
-
-	sts = lpuart32_read(&sport->port, UARTSTAT);
-	rxcount = lpuart32_read(&sport->port, UARTWATER);
-	rxcount = rxcount >> UARTWATER_RXCNT_OFF;
-
-	if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use)
-		lpuart32_rxint(sport);
-
-	if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use)
-		lpuart32_txint(sport);
-
-	lpuart32_write(&sport->port, sts, UARTSTAT);
-	return IRQ_HANDLED;
-}
-
-
 static inline void lpuart_handle_sysrq_chars(struct uart_port *port,
 					     unsigned char *p, int count)
 {
@@ -1266,7 +1247,8 @@ exit:
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 
 	tty_flip_buffer_push(port);
-	mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
+	if (!sport->dma_idle_int)
+		mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout);
 }
 
 static void lpuart_dma_rx_complete(void *arg)
@@ -1276,6 +1258,50 @@ static void lpuart_dma_rx_complete(void *arg)
 	lpuart_copy_rx_to_tty(sport);
 }
 
+static void lpuart32_dma_idleint(struct lpuart_port *sport)
+{
+	enum dma_status dmastat;
+	struct dma_chan *chan = sport->dma_rx_chan;
+	struct circ_buf *ring = &sport->rx_ring;
+	struct dma_tx_state state;
+	int count = 0;
+
+	dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
+	if (dmastat == DMA_ERROR) {
+		dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
+		return;
+	}
+
+	ring->head = sport->rx_sgl.length - state.residue;
+	count = CIRC_CNT(ring->head, ring->tail, sport->rx_sgl.length);
+
+	/* Check if new data received before copying */
+	if (count)
+		lpuart_copy_rx_to_tty(sport);
+}
+
+static irqreturn_t lpuart32_int(int irq, void *dev_id)
+{
+	struct lpuart_port *sport = dev_id;
+	unsigned long sts, rxcount;
+
+	sts = lpuart32_read(&sport->port, UARTSTAT);
+	rxcount = lpuart32_read(&sport->port, UARTWATER);
+	rxcount = rxcount >> UARTWATER_RXCNT_OFF;
+
+	if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use)
+		lpuart32_rxint(sport);
+
+	if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use)
+		lpuart32_txint(sport);
+
+	if ((sts & UARTSTAT_IDLE) && sport->lpuart_dma_rx_use && sport->dma_idle_int)
+		lpuart32_dma_idleint(sport);
+
+	lpuart32_write(&sport->port, sts, UARTSTAT);
+	return IRQ_HANDLED;
+}
+
 /*
  * Timer function to simulate the hardware EOP (End Of Package) event.
  * The timer callback is to check for new RX data and copy to TTY buffer.
@@ -1392,6 +1418,12 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 		unsigned long temp = lpuart32_read(&sport->port, UARTBAUD);
 
 		lpuart32_write(&sport->port, temp | UARTBAUD_RDMAE, UARTBAUD);
+
+		if (sport->dma_idle_int) {
+			unsigned long ctrl = lpuart32_read(&sport->port, UARTCTRL);
+
+			lpuart32_write(&sport->port, ctrl | UARTCTRL_ILIE, UARTCTRL);
+		}
 	} else {
 		writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS,
 		       sport->port.membase + UARTCR5);
@@ -1407,7 +1439,9 @@ static void lpuart_dma_rx_free(struct uart_port *port)
 	struct dma_chan *chan = sport->dma_rx_chan;
 
 	dmaengine_terminate_sync(chan);
-	del_timer_sync(&sport->lpuart_timer);
+	if (!sport->dma_idle_int)
+		del_timer_sync(&sport->lpuart_timer);
+
 	dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE);
 	kfree(sport->rx_ring.buf);
 	sport->rx_ring.tail = 0;
@@ -1669,6 +1703,9 @@ static void lpuart32_setup_watermark_enable(struct lpuart_port *sport)
 
 static void rx_dma_timer_init(struct lpuart_port *sport)
 {
+	if (sport->dma_idle_int)
+		return;
+
 	timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0);
 	sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout;
 	add_timer(&sport->lpuart_timer);
@@ -2811,8 +2848,7 @@ static int lpuart_probe(struct platform_device *pdev)
 	if (!sport)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	sport->port.membase = devm_ioremap_resource(&pdev->dev, res);
+	sport->port.membase = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 	if (IS_ERR(sport->port.membase))
 		return PTR_ERR(sport->port.membase);
 
@@ -2822,6 +2858,8 @@ static int lpuart_probe(struct platform_device *pdev)
 	sport->port.type = PORT_LPUART;
 	sport->devtype = sdata->devtype;
 	sport->rx_watermark = sdata->rx_watermark;
+	sport->dma_idle_int = is_imx7ulp_lpuart(sport) || is_imx8ulp_lpuart(sport) ||
+			      is_imx8qxp_lpuart(sport);
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0)
 		return ret;