Merge tag 'tty-6.0-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 6.0-rc1.

  It was delayed from last week as I wanted to make sure the last commit
  here got some good testing in linux-next and elsewhere as it seemed to
  show up only late in testing for some reason.

  Nothing major here, just lots of cleanups from Jiri and Ilpo to make
  the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo).

  Also included in here is the obligatory n_gsm updates from Daniel
  Starke and lots of tiny driver updates and minor fixes and tweaks for
  other smaller serial drivers.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits)
  tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements
  tty: amiserial: Fix comment typo
  tty: serial: document uart_get_console()
  tty: serial: serial_core, reformat kernel-doc for functions
  Documentation: serial: link uart_ops properly
  Documentation: serial: move GPIO kernel-doc to the functions
  Documentation: serial: dedup kernel-doc for uart functions
  Documentation: serial: move uart_ops documentation to the struct
  dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126
  serial: mvebu-uart: uart2 error bits clearing
  tty: serial: fsl_lpuart: correct the count of break characters
  serial: stm32: make info structs static to avoid sparse warnings
  serial: fsl_lpuart: zero out parity bit in CS7 mode
  tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate.
  serial: 8250_bcm2835aux: Add missing clk_disable_unprepare()
  tty: vt: initialize unicode screen buffer
  serial: remove VR41XX serial driver
  serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags
  serial: 8250_dwlib: remove redundant sanity check for RS485 flags
  dt_bindings: rs485: Correct delay values
  ...

1 files changed, 39 insertions, 29 deletions

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index bb6aca07ab56..a604b42e4458 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -9,26 +9,27 @@
  * LCR is written whilst busy.  If it is, then a busy detect interrupt is
  * raised, the LCR needs to be rewritten and the uart status register read.
  */
+#include <linux/acpi.h>
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
-#include <linux/serial_8250.h>
-#include <linux/serial_reg.h>
+#include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
-#include <linux/workqueue.h>
-#include <linux/notifier.h>
-#include <linux/slab.h>
-#include <linux/acpi.h>
-#include <linux/clk.h>
 #include <linux/reset.h>
-#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
 
 #include <asm/byteorder.h>
 
+#include <linux/serial_8250.h>
+#include <linux/serial_reg.h>
+
 #include "8250_dwlib.h"
 
 /* Offsets for the DesignWare specific registers */
@@ -82,8 +83,21 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
 static void dw8250_force_idle(struct uart_port *p)
 {
 	struct uart_8250_port *up = up_to_u8250p(p);
+	unsigned int lsr;
 
 	serial8250_clear_and_reinit_fifos(up);
+
+	/*
+	 * With PSLVERR_RESP_EN parameter set to 1, the device generates an
+	 * error response when an attempt to read an empty RBR with FIFO
+	 * enabled.
+	 */
+	if (up->fcr & UART_FCR_ENABLE_FIFO) {
+		lsr = p->serial_in(p, UART_LSR);
+		if (!(lsr & UART_LSR_DR))
+			return;
+	}
+
 	(void)p->serial_in(p, UART_RX);
 }
 
@@ -122,12 +136,15 @@ static void dw8250_check_lcr(struct uart_port *p, int value)
 /* Returns once the transmitter is empty or we run out of retries */
 static void dw8250_tx_wait_empty(struct uart_port *p)
 {
+	struct uart_8250_port *up = up_to_u8250p(p);
 	unsigned int tries = 20000;
 	unsigned int delay_threshold = tries - 1000;
 	unsigned int lsr;
 
 	while (tries--) {
 		lsr = readb (p->membase + (UART_LSR << p->regshift));
+		up->lsr_saved_flags |= lsr & up->lsr_save_mask;
+
 		if (lsr & UART_LSR_TEMT)
 			break;
 
@@ -140,29 +157,23 @@ static void dw8250_tx_wait_empty(struct uart_port *p)
 	}
 }
 
-static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
 {
 	struct dw8250_data *d = to_dw8250_data(p->private_data);
 
-	/* Allow the TX to drain before we reconfigure */
-	if (offset == UART_LCR)
-		dw8250_tx_wait_empty(p);
-
 	writeb(value, p->membase + (offset << p->regshift));
 
 	if (offset == UART_LCR && !d->uart_16550_compatible)
 		dw8250_check_lcr(p, value);
 }
 
-
-static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
 {
-	struct dw8250_data *d = to_dw8250_data(p->private_data);
-
-	writeb(value, p->membase + (offset << p->regshift));
+	/* Allow the TX to drain before we reconfigure */
+	if (offset == UART_LCR)
+		dw8250_tx_wait_empty(p);
 
-	if (offset == UART_LCR && !d->uart_16550_compatible)
-		dw8250_check_lcr(p, value);
+	dw8250_serial_out(p, offset, value);
 }
 
 static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
@@ -253,7 +264,7 @@ static int dw8250_handle_irq(struct uart_port *p)
 	 */
 	if (!up->dma && rx_timeout) {
 		spin_lock_irqsave(&p->lock, flags);
-		status = p->serial_in(p, UART_LSR);
+		status = serial_lsr_in(up);
 
 		if (!(status & (UART_LSR_DR | UART_LSR_BI)))
 			(void) p->serial_in(p, UART_RX);
@@ -263,7 +274,10 @@ static int dw8250_handle_irq(struct uart_port *p)
 
 	/* Manually stop the Rx DMA transfer when acting as flow controller */
 	if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) {
-		status = p->serial_in(p, UART_LSR);
+		spin_lock_irqsave(&p->lock, flags);
+		status = serial_lsr_in(up);
+		spin_unlock_irqrestore(&p->lock, flags);
+
 		if (status & (UART_LSR_DR | UART_LSR_BI)) {
 			dw8250_writel_ext(p, RZN1_UART_RDMACR, 0);
 			dw8250_writel_ext(p, DW_UART_DMASA, 1);
@@ -688,7 +702,6 @@ static int dw8250_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int dw8250_suspend(struct device *dev)
 {
 	struct dw8250_data *data = dev_get_drvdata(dev);
@@ -706,9 +719,7 @@ static int dw8250_resume(struct device *dev)
 
 	return 0;
 }
-#endif /* CONFIG_PM_SLEEP */
 
-#ifdef CONFIG_PM
 static int dw8250_runtime_suspend(struct device *dev)
 {
 	struct dw8250_data *data = dev_get_drvdata(dev);
@@ -730,11 +741,10 @@ static int dw8250_runtime_resume(struct device *dev)
 
 	return 0;
 }
-#endif
 
 static const struct dev_pm_ops dw8250_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
-	SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume)
+	RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL)
 };
 
 static const struct dw8250_platform_data dw8250_dw_apb = {
@@ -792,7 +802,7 @@ MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match);
 static struct platform_driver dw8250_platform_driver = {
 	.driver = {
 		.name		= "dw-apb-uart",
-		.pm		= &dw8250_pm_ops,
+		.pm		= pm_ptr(&dw8250_pm_ops),
 		.of_match_table	= dw8250_of_match,
 		.acpi_match_table = dw8250_acpi_match,
 	},