Merge tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the large TTY/Serial driver set of patches for 4.21-rc1.

  A number of small serial driver changes along with some good tty core
  fixes for long-reported issues with locking. There is also a new
  console font added to the tree, for high-res screens, so that should
  be helpful for many.

  The last patch in the series is a revert of an older one in the tree,
  it came late but it resolves a reported issue that linux-next was
  having for some people.

  Full details are in the shortlog, and all of these, with the exception
  of the revert, have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits)
  Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250"
  serial: sccnxp: Allow to use non-standard baud rates
  serial: sccnxp: Adds a delay between sequential read/write cycles
  tty: serial: qcom_geni_serial: Fix UART hang
  tty: serial: qcom_geni_serial: Fix wrap around of TX buffer
  serial: max310x: Fix tx_empty() callback
  dt-bindings: serial: sh-sci: Document r8a774c0 bindings
  dt-bindings: serial: sh-sci: Document r8a774a1 bindings
  Fonts: New Terminus large console font
  dt-bindings: serial: lpuart: add imx8qxp compatible string
  serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly
  serial: uartps: Fix error path when alloc failed
  serial: uartps: Check if the device is a console
  serial: uartps: Add the device_init_wakeup
  tty: serial: samsung: Increase maximum baudrate
  tty: serial: samsung: Properly set flags in autoCTS mode
  tty: Use of_node_name_{eq,prefix} for node name comparisons
  tty/serial: do not free trasnmit buffer page under port lock
  serial: 8250: Rate limit serial port rx interrupts during input overruns
  dt-bindings: serial: 8250: Add rate limit for serial port input overruns
  ...

1 files changed, 46 insertions, 8 deletions

diff --git a/drivers/tty/serial/sccnxp.c b/drivers/tty/serial/sccnxp.c
index 339befdd2f4d..68a24a14f6b7 100644
--- a/drivers/tty/serial/sccnxp.c
+++ b/drivers/tty/serial/sccnxp.c
@@ -12,6 +12,7 @@
 #endif
 
 #include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
@@ -47,7 +48,6 @@
 #	define MR2_STOP1		(7 << 0)
 #	define MR2_STOP2		(0xf << 0)
 #define SCCNXP_SR_REG			(0x01)
-#define SCCNXP_CSR_REG			SCCNXP_SR_REG
 #	define SR_RXRDY			(1 << 0)
 #	define SR_FULL			(1 << 1)
 #	define SR_TXRDY			(1 << 2)
@@ -56,6 +56,8 @@
 #	define SR_PE			(1 << 5)
 #	define SR_FE			(1 << 6)
 #	define SR_BRK			(1 << 7)
+#define SCCNXP_CSR_REG			(SCCNXP_SR_REG)
+#	define CSR_TIMER_MODE		(0x0d)
 #define SCCNXP_CR_REG			(0x02)
 #	define CR_RX_ENABLE		(1 << 0)
 #	define CR_RX_DISABLE		(1 << 1)
@@ -82,9 +84,12 @@
 #	define IMR_RXRDY		(1 << 1)
 #	define ISR_TXRDY(x)		(1 << ((x * 4) + 0))
 #	define ISR_RXRDY(x)		(1 << ((x * 4) + 1))
+#define SCCNXP_CTPU_REG			(0x06)
+#define SCCNXP_CTPL_REG			(0x07)
 #define SCCNXP_IPR_REG			(0x0d)
 #define SCCNXP_OPCR_REG			SCCNXP_IPR_REG
 #define SCCNXP_SOP_REG			(0x0e)
+#define SCCNXP_START_COUNTER_REG	SCCNXP_SOP_REG
 #define SCCNXP_ROP_REG			(0x0f)
 
 /* Route helpers */
@@ -103,6 +108,8 @@ struct sccnxp_chip {
 	unsigned long		freq_max;
 	unsigned int		flags;
 	unsigned int		fifosize;
+	/* Time between read/write cycles */
+	unsigned int		trwd;
 };
 
 struct sccnxp_port {
@@ -137,6 +144,7 @@ static const struct sccnxp_chip sc2681 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 200,
 };
 
 static const struct sccnxp_chip sc2691 = {
@@ -147,6 +155,7 @@ static const struct sccnxp_chip sc2691 = {
 	.freq_max	= 4000000,
 	.flags		= 0,
 	.fifosize	= 3,
+	.trwd		= 150,
 };
 
 static const struct sccnxp_chip sc2692 = {
@@ -157,6 +166,7 @@ static const struct sccnxp_chip sc2692 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 30,
 };
 
 static const struct sccnxp_chip sc2891 = {
@@ -167,6 +177,7 @@ static const struct sccnxp_chip sc2891 = {
 	.freq_max	= 8000000,
 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
 	.fifosize	= 16,
+	.trwd		= 27,
 };
 
 static const struct sccnxp_chip sc2892 = {
@@ -177,6 +188,7 @@ static const struct sccnxp_chip sc2892 = {
 	.freq_max	= 8000000,
 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
 	.fifosize	= 16,
+	.trwd		= 17,
 };
 
 static const struct sccnxp_chip sc28202 = {
@@ -187,6 +199,7 @@ static const struct sccnxp_chip sc28202 = {
 	.freq_max	= 50000000,
 	.flags		= SCCNXP_HAVE_IO | SCCNXP_HAVE_MR0,
 	.fifosize	= 256,
+	.trwd		= 10,
 };
 
 static const struct sccnxp_chip sc68681 = {
@@ -197,6 +210,7 @@ static const struct sccnxp_chip sc68681 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 200,
 };
 
 static const struct sccnxp_chip sc68692 = {
@@ -207,24 +221,36 @@ static const struct sccnxp_chip sc68692 = {
 	.freq_max	= 4000000,
 	.flags		= SCCNXP_HAVE_IO,
 	.fifosize	= 3,
+	.trwd		= 200,
 };
 
-static inline u8 sccnxp_read(struct uart_port *port, u8 reg)
+static u8 sccnxp_read(struct uart_port *port, u8 reg)
 {
-	return readb(port->membase + (reg << port->regshift));
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+	u8 ret;
+
+	ret = readb(port->membase + (reg << port->regshift));
+
+	ndelay(s->chip->trwd);
+
+	return ret;
 }
 
-static inline void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
+static void sccnxp_write(struct uart_port *port, u8 reg, u8 v)
 {
+	struct sccnxp_port *s = dev_get_drvdata(port->dev);
+
 	writeb(v, port->membase + (reg << port->regshift));
+
+	ndelay(s->chip->trwd);
 }
 
-static inline u8 sccnxp_port_read(struct uart_port *port, u8 reg)
+static u8 sccnxp_port_read(struct uart_port *port, u8 reg)
 {
 	return sccnxp_read(port, (port->line << 3) + reg);
 }
 
-static inline void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
+static void sccnxp_port_write(struct uart_port *port, u8 reg, u8 v)
 {
 	sccnxp_write(port, (port->line << 3) + reg, v);
 }
@@ -233,7 +259,7 @@ static int sccnxp_update_best_err(int a, int b, int *besterr)
 {
 	int err = abs(a - b);
 
-	if ((*besterr < 0) || (*besterr > err)) {
+	if (*besterr > err) {
 		*besterr = err;
 		return 0;
 	}
@@ -281,10 +307,22 @@ static const struct {
 static int sccnxp_set_baud(struct uart_port *port, int baud)
 {
 	struct sccnxp_port *s = dev_get_drvdata(port->dev);
-	int div_std, tmp_baud, bestbaud = baud, besterr = -1;
+	int div_std, tmp_baud, bestbaud = INT_MAX, besterr = INT_MAX;
 	struct sccnxp_chip *chip = s->chip;
 	u8 i, acr = 0, csr = 0, mr0 = 0;
 
+	/* Find divisor to load to the timer preset registers */
+	div_std = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * baud);
+	if ((div_std >= 2) && (div_std <= 0xffff)) {
+		bestbaud = DIV_ROUND_CLOSEST(port->uartclk, 2 * 16 * div_std);
+		sccnxp_update_best_err(baud, bestbaud, &besterr);
+		csr = CSR_TIMER_MODE;
+		sccnxp_port_write(port, SCCNXP_CTPU_REG, div_std >> 8);
+		sccnxp_port_write(port, SCCNXP_CTPL_REG, div_std);
+		/* Issue start timer/counter command */
+		sccnxp_port_read(port, SCCNXP_START_COUNTER_REG);
+	}
+
 	/* Find best baud from table */
 	for (i = 0; baud_std[i].baud && besterr; i++) {
 		if (baud_std[i].mr0 && !(chip->flags & SCCNXP_HAVE_MR0))