Merging upstream version 5.10.216.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

11 files changed, 353 insertions, 146 deletions

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 43f2eed6d..355ee338d 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1026,6 +1026,7 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		uart->port.throttle	= up->port.throttle;
 		uart->port.unthrottle	= up->port.unthrottle;
 		uart->port.rs485_config	= up->port.rs485_config;
+		uart->port.rs485_supported = up->port.rs485_supported;
 		uart->port.rs485	= up->port.rs485;
 		uart->rs485_start_tx	= up->rs485_start_tx;
 		uart->rs485_stop_tx	= up->rs485_stop_tx;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 5c2adf140..7c28d2752 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -123,6 +123,7 @@ struct exar8250;
 
 struct exar8250_platform {
 	int (*rs485_config)(struct uart_port *, struct serial_rs485 *);
+	const struct serial_rs485 *rs485_supported;
 	int (*register_gpio)(struct pci_dev *, struct uart_8250_port *);
 };
 
@@ -423,9 +424,14 @@ static int generic_rs485_config(struct uart_port *port,
 	return 0;
 }
 
+static const struct serial_rs485 generic_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND,
+};
+
 static const struct exar8250_platform exar8250_default_platform = {
 	.register_gpio = xr17v35x_register_gpio,
 	.rs485_config = generic_rs485_config,
+	.rs485_supported = &generic_rs485_supported,
 };
 
 static int iot2040_rs485_config(struct uart_port *port,
@@ -461,6 +467,11 @@ static int iot2040_rs485_config(struct uart_port *port,
 	return generic_rs485_config(port, rs485);
 }
 
+static const struct serial_rs485 iot2040_rs485_supported = {
+	.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
+		 SER_RS485_RX_DURING_TX | SER_RS485_TERMINATE_BUS,
+};
+
 static const struct property_entry iot2040_gpio_properties[] = {
 	PROPERTY_ENTRY_U32("exar,first-pin", 10),
 	PROPERTY_ENTRY_U32("ngpios", 1),
@@ -485,6 +496,7 @@ static int iot2040_register_gpio(struct pci_dev *pcidev,
 
 static const struct exar8250_platform iot2040_platform = {
 	.rs485_config = iot2040_rs485_config,
+	.rs485_supported = &iot2040_rs485_supported,
 	.register_gpio = iot2040_register_gpio,
 };
 
@@ -522,6 +534,7 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 
 	port->port.uartclk = baud * 16;
 	port->port.rs485_config = platform->rs485_config;
+	port->port.rs485_supported = platform->rs485_supported;
 
 	/*
 	 * Setup the UART clock for the devices on expansion slot to
@@ -675,6 +688,7 @@ static void exar_pci_remove(struct pci_dev *pcidev)
 	for (i = 0; i < priv->nr; i++)
 		serial8250_unregister_port(priv->line[i]);
 
+	/* Ensure that every init quirk is properly torn down */
 	if (priv->board->exit)
 		priv->board->exit(pcidev);
 }
@@ -689,10 +703,6 @@ static int __maybe_unused exar_suspend(struct device *dev)
 		if (priv->line[i] >= 0)
 			serial8250_suspend_port(priv->line[i]);
 
-	/* Ensure that every init quirk is properly torn down */
-	if (priv->board->exit)
-		priv->board->exit(pcidev);
-
 	return 0;
 }
 
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 8b49ac485..6098e87a3 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1358,9 +1358,6 @@ static void autoconfig_irq(struct uart_8250_port *up)
 		inb_p(ICP);
 	}
 
-	if (uart_console(port))
-		console_lock();
-
 	/* forget possible initially masked and pending IRQ */
 	probe_irq_off(probe_irq_on());
 	save_mcr = serial8250_in_MCR(up);
@@ -1391,9 +1388,6 @@ static void autoconfig_irq(struct uart_8250_port *up)
 	if (port->flags & UPF_FOURPORT)
 		outb_p(save_ICP, ICP);
 
-	if (uart_console(port))
-		console_unlock();
-
 	port->irq = (irq > 0) ? irq : 0;
 }
 
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 28f22e586..bd30ae975 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -343,6 +343,7 @@ config SERIAL_MAX310X
 	depends on SPI_MASTER
 	select SERIAL_CORE
 	select REGMAP_SPI if SPI_MASTER
+	select REGMAP_I2C if I2C
 	help
 	  This selects support for an advanced UART from Maxim (Dallas).
 	  Supported ICs are MAX3107, MAX3108, MAX3109, MAX14830.
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 227fb2d32..b16ad6db1 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2178,9 +2178,12 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 		       UARTCTRL);
 
 	lpuart32_serial_setbrg(sport, baud);
-	lpuart32_write(&sport->port, modem, UARTMODIR);
-	lpuart32_write(&sport->port, ctrl, UARTCTRL);
+	/* disable CTS before enabling UARTCTRL_TE to avoid pending idle preamble */
+	lpuart32_write(&sport->port, modem & ~UARTMODIR_TXCTSE, UARTMODIR);
 	/* restore control register */
+	lpuart32_write(&sport->port, ctrl, UARTCTRL);
+	/* re-enable the CTS if needed */
+	lpuart32_write(&sport->port, modem, UARTMODIR);
 
 	if (old && sport->lpuart_dma_rx_use) {
 		if (!lpuart_start_rx_dma(sport))
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 5bf8dd619..363b68555 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -14,9 +14,10 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/gpio/driver.h>
+#include <linux/i2c.h>
 #include <linux/module.h>
-#include <linux/of.h>
-#include <linux/of_device.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
@@ -72,7 +73,8 @@
 #define MAX310X_GLOBALCMD_REG		MAX310X_REG_1F /* Global Command (WO) */
 
 /* Extended registers */
-#define MAX310X_REVID_EXTREG		MAX310X_REG_05 /* Revision ID */
+#define MAX310X_SPI_REVID_EXTREG	MAX310X_REG_05 /* Revision ID */
+#define MAX310X_I2C_REVID_EXTREG	(0x25) /* Revision ID */
 
 /* IRQ register bits */
 #define MAX310X_IRQ_LSR_BIT		(1 << 0) /* LSR interrupt */
@@ -235,6 +237,14 @@
 #define MAX310x_REV_MASK		(0xf8)
 #define MAX310X_WRITE_BIT		0x80
 
+/* Port startup definitions */
+#define MAX310X_PORT_STARTUP_WAIT_RETRIES	20 /* Number of retries */
+#define MAX310X_PORT_STARTUP_WAIT_DELAY_MS	10 /* Delay between retries */
+
+/* Crystal-related definitions */
+#define MAX310X_XTAL_WAIT_RETRIES	20 /* Number of retries */
+#define MAX310X_XTAL_WAIT_DELAY_MS	10 /* Delay between retries */
+
 /* MAX3107 specific */
 #define MAX3107_REV_ID			(0xa0)
 
@@ -245,7 +255,17 @@
 #define MAX14830_BRGCFG_CLKDIS_BIT	(1 << 6) /* Clock Disable */
 #define MAX14830_REV_ID			(0xb0)
 
+struct max310x_if_cfg {
+	int (*extended_reg_enable)(struct device *dev, bool enable);
+
+	unsigned int rev_id_reg;
+};
+
 struct max310x_devtype {
+	struct {
+		unsigned short min;
+		unsigned short max;
+	} slave_addr;
 	char	name[9];
 	int	nr;
 	u8	mode1;
@@ -258,16 +278,16 @@ struct max310x_one {
 	struct work_struct	tx_work;
 	struct work_struct	md_work;
 	struct work_struct	rs_work;
+	struct regmap		*regmap;
 
-	u8 wr_header;
-	u8 rd_header;
 	u8 rx_buf[MAX310X_FIFO_SIZE];
 };
 #define to_max310x_port(_port) \
 	container_of(_port, struct max310x_one, port)
 
 struct max310x_port {
-	struct max310x_devtype	*devtype;
+	const struct max310x_devtype *devtype;
+	const struct max310x_if_cfg *if_cfg;
 	struct regmap		*regmap;
 	struct clk		*clk;
 #ifdef CONFIG_GPIOLIB
@@ -289,26 +309,26 @@ static DECLARE_BITMAP(max310x_lines, MAX310X_UART_NRMAX);
 
 static u8 max310x_port_read(struct uart_port *port, u8 reg)
 {
-	struct max310x_port *s = dev_get_drvdata(port->dev);
+	struct max310x_one *one = to_max310x_port(port);
 	unsigned int val = 0;
 
-	regmap_read(s->regmap, port->iobase + reg, &val);
+	regmap_read(one->regmap, reg, &val);
 
 	return val;
 }
 
 static void max310x_port_write(struct uart_port *port, u8 reg, u8 val)
 {
-	struct max310x_port *s = dev_get_drvdata(port->dev);
+	struct max310x_one *one = to_max310x_port(port);
 
-	regmap_write(s->regmap, port->iobase + reg, val);
+	regmap_write(one->regmap, reg, val);
 }
 
 static void max310x_port_update(struct uart_port *port, u8 reg, u8 mask, u8 val)
 {
-	struct max310x_port *s = dev_get_drvdata(port->dev);
+	struct max310x_one *one = to_max310x_port(port);
 
-	regmap_update_bits(s->regmap, port->iobase + reg, mask, val);
+	regmap_update_bits(one->regmap, reg, mask, val);
 }
 
 static int max3107_detect(struct device *dev)
@@ -357,13 +377,12 @@ static int max3109_detect(struct device *dev)
 	unsigned int val = 0;
 	int ret;
 
-	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
-			   MAX310X_EXTREG_ENBL);
+	ret = s->if_cfg->extended_reg_enable(dev, true);
 	if (ret)
 		return ret;
 
-	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
-	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
+	regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
+	s->if_cfg->extended_reg_enable(dev, false);
 	if (((val & MAX310x_REV_MASK) != MAX3109_REV_ID)) {
 		dev_err(dev,
 			"%s ID 0x%02x does not match\n", s->devtype->name, val);
@@ -388,13 +407,12 @@ static int max14830_detect(struct device *dev)
 	unsigned int val = 0;
 	int ret;
 
-	ret = regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
-			   MAX310X_EXTREG_ENBL);
+	ret = s->if_cfg->extended_reg_enable(dev, true);
 	if (ret)
 		return ret;
 	
-	regmap_read(s->regmap, MAX310X_REVID_EXTREG, &val);
-	regmap_write(s->regmap, MAX310X_GLOBALCMD_REG, MAX310X_EXTREG_DSBL);
+	regmap_read(s->regmap, s->if_cfg->rev_id_reg, &val);
+	s->if_cfg->extended_reg_enable(dev, false);
 	if (((val & MAX310x_REV_MASK) != MAX14830_REV_ID)) {
 		dev_err(dev,
 			"%s ID 0x%02x does not match\n", s->devtype->name, val);
@@ -419,6 +437,10 @@ static const struct max310x_devtype max3107_devtype = {
 	.mode1	= MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT,
 	.detect	= max3107_detect,
 	.power	= max310x_power,
+	.slave_addr	= {
+		.min = 0x2c,
+		.max = 0x2f,
+	},
 };
 
 static const struct max310x_devtype max3108_devtype = {
@@ -427,6 +449,10 @@ static const struct max310x_devtype max3108_devtype = {
 	.mode1	= MAX310X_MODE1_AUTOSLEEP_BIT,
 	.detect	= max3108_detect,
 	.power	= max310x_power,
+	.slave_addr	= {
+		.min = 0x60,
+		.max = 0x6f,
+	},
 };
 
 static const struct max310x_devtype max3109_devtype = {
@@ -435,6 +461,10 @@ static const struct max310x_devtype max3109_devtype = {
 	.mode1	= MAX310X_MODE1_AUTOSLEEP_BIT,
 	.detect	= max3109_detect,
 	.power	= max310x_power,
+	.slave_addr	= {
+		.min = 0x60,
+		.max = 0x6f,
+	},
 };
 
 static const struct max310x_devtype max14830_devtype = {
@@ -443,11 +473,15 @@ static const struct max310x_devtype max14830_devtype = {
 	.mode1	= MAX310X_MODE1_IRQSEL_BIT,
 	.detect	= max14830_detect,
 	.power	= max14830_power,
+	.slave_addr	= {
+		.min = 0x60,
+		.max = 0x6f,
+	},
 };
 
 static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
 {
-	switch (reg & 0x1f) {
+	switch (reg) {
 	case MAX310X_IRQSTS_REG:
 	case MAX310X_LSR_IRQSTS_REG:
 	case MAX310X_SPCHR_IRQSTS_REG:
@@ -464,7 +498,7 @@ static bool max310x_reg_writeable(struct device *dev, unsigned int reg)
 
 static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
 {
-	switch (reg & 0x1f) {
+	switch (reg) {
 	case MAX310X_RHR_REG:
 	case MAX310X_IRQSTS_REG:
 	case MAX310X_LSR_IRQSTS_REG:
@@ -486,7 +520,7 @@ static bool max310x_reg_volatile(struct device *dev, unsigned int reg)
 
 static bool max310x_reg_precious(struct device *dev, unsigned int reg)
 {
-	switch (reg & 0x1f) {
+	switch (reg) {
 	case MAX310X_RHR_REG:
 	case MAX310X_IRQSTS_REG:
 	case MAX310X_SPCHR_IRQSTS_REG:
@@ -499,6 +533,11 @@ static bool max310x_reg_precious(struct device *dev, unsigned int reg)
 	return false;
 }
 
+static bool max310x_reg_noinc(struct device *dev, unsigned int reg)
+{
+	return reg == MAX310X_RHR_REG;
+}
+
 static int max310x_set_baud(struct uart_port *port, int baud)
 {
 	unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
@@ -552,7 +591,7 @@ static int max310x_update_best_err(unsigned long f, long *besterr)
 	return 1;
 }
 
-static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
+static s32 max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
 			       unsigned long freq, bool xtal)
 {
 	unsigned int div, clksrc, pllcfg = 0;
@@ -610,45 +649,37 @@ static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
 
 	/* Wait for crystal */
 	if (xtal) {
-		unsigned int val;
-		msleep(10);
-		regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
-		if (!(val & MAX310X_STS_CLKREADY_BIT)) {
-			dev_warn(dev, "clock is not stable yet\n");
-		}
+		bool stable = false;
+		unsigned int try = 0, val = 0;
+
+		do {
+			msleep(MAX310X_XTAL_WAIT_DELAY_MS);
+			regmap_read(s->regmap, MAX310X_STS_IRQSTS_REG, &val);
+
+			if (val & MAX310X_STS_CLKREADY_BIT)
+				stable = true;
+		} while (!stable && (++try < MAX310X_XTAL_WAIT_RETRIES));
+
+		if (!stable)
+			return dev_err_probe(dev, -EAGAIN,
+					     "clock is not stable\n");
 	}
 
-	return (int)bestfreq;
+	return bestfreq;
 }
 
 static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
 {
 	struct max310x_one *one = to_max310x_port(port);
-	struct spi_transfer xfer[] = {
-		{
-			.tx_buf = &one->wr_header,
-			.len = sizeof(one->wr_header),
-		}, {
-			.tx_buf = txbuf,
-			.len = len,
-		}
-	};
-	spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
+
+	regmap_noinc_write(one->regmap, MAX310X_THR_REG, txbuf, len);
 }
 
 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
 {
 	struct max310x_one *one = to_max310x_port(port);
-	struct spi_transfer xfer[] = {
-		{
-			.tx_buf = &one->rd_header,
-			.len = sizeof(one->rd_header),
-		}, {
-			.rx_buf = rxbuf,
-			.len = len,
-		}
-	};
-	spi_sync_transfer(to_spi_device(port->dev), xfer, ARRAY_SIZE(xfer));
+
+	regmap_noinc_read(one->regmap, MAX310X_RHR_REG, rxbuf, len);
 }
 
 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
@@ -1250,16 +1281,18 @@ static int max310x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
 }
 #endif
 
-static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
-			 struct regmap *regmap, int irq)
+static int max310x_probe(struct device *dev, const struct max310x_devtype *devtype,
+			 const struct max310x_if_cfg *if_cfg,
+			 struct regmap *regmaps[], int irq)
 {
-	int i, ret, fmin, fmax, freq, uartclk;
-	struct clk *clk_osc, *clk_xtal;
+	int i, ret, fmin, fmax, freq;
 	struct max310x_port *s;
-	bool xtal = false;
+	s32 uartclk = 0;
+	bool xtal;
 
-	if (IS_ERR(regmap))
-		return PTR_ERR(regmap);
+	for (i = 0; i < devtype->nr; i++)
+		if (IS_ERR(regmaps[i]))
+			return PTR_ERR(regmaps[i]);
 
 	/* Alloc port structure */
 	s = devm_kzalloc(dev, struct_size(s, p, devtype->nr), GFP_KERNEL);
@@ -1268,23 +1301,20 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		return -ENOMEM;
 	}
 
-	clk_osc = devm_clk_get(dev, "osc");
-	clk_xtal = devm_clk_get(dev, "xtal");
-	if (!IS_ERR(clk_osc)) {
-		s->clk = clk_osc;
-		fmin = 500000;
-		fmax = 35000000;
-	} else if (!IS_ERR(clk_xtal)) {
-		s->clk = clk_xtal;
-		fmin = 1000000;
-		fmax = 4000000;
-		xtal = true;
-	} else if (PTR_ERR(clk_osc) == -EPROBE_DEFER ||
-		   PTR_ERR(clk_xtal) == -EPROBE_DEFER) {
-		return -EPROBE_DEFER;
+	/* Always ask for fixed clock rate from a property. */
+	device_property_read_u32(dev, "clock-frequency", &uartclk);
+
+	s->clk = devm_clk_get_optional(dev, "osc");
+	if (IS_ERR(s->clk))
+		return PTR_ERR(s->clk);
+	if (s->clk) {
+		xtal = false;
 	} else {
-		dev_err(dev, "Cannot get clock\n");
-		return -EINVAL;
+		s->clk = devm_clk_get_optional(dev, "xtal");
+		if (IS_ERR(s->clk))
+			return PTR_ERR(s->clk);
+
+		xtal = true;
 	}
 
 	ret = clk_prepare_enable(s->clk);
@@ -1292,14 +1322,31 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		return ret;
 
 	freq = clk_get_rate(s->clk);
+	if (freq == 0)
+		freq = uartclk;
+	if (freq == 0) {
+		dev_err(dev, "Cannot get clock rate\n");
+		ret = -EINVAL;
+		goto out_clk;
+	}
+
+	if (xtal) {
+		fmin = 1000000;
+		fmax = 4000000;
+	} else {
+		fmin = 500000;
+		fmax = 35000000;
+	}
+
 	/* Check frequency limits */
 	if (freq < fmin || freq > fmax) {
 		ret = -ERANGE;
 		goto out_clk;
 	}
 
-	s->regmap = regmap;
+	s->regmap = regmaps[0];
 	s->devtype = devtype;
+	s->if_cfg = if_cfg;
 	dev_set_drvdata(dev, s);
 
 	/* Check device to ensure we are talking to what we expect */
@@ -1308,25 +1355,38 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		goto out_clk;
 
 	for (i = 0; i < devtype->nr; i++) {
-		unsigned int offs = i << 5;
+		bool started = false;
+		unsigned int try = 0, val = 0;
 
 		/* Reset port */
-		regmap_write(s->regmap, MAX310X_MODE2_REG + offs,
+		regmap_write(regmaps[i], MAX310X_MODE2_REG,
 			     MAX310X_MODE2_RST_BIT);
 		/* Clear port reset */
-		regmap_write(s->regmap, MAX310X_MODE2_REG + offs, 0);
+		regmap_write(regmaps[i], MAX310X_MODE2_REG, 0);
 
 		/* Wait for port startup */
 		do {
-			regmap_read(s->regmap,
-				    MAX310X_BRGDIVLSB_REG + offs, &ret);
-		} while (ret != 0x01);
+			msleep(MAX310X_PORT_STARTUP_WAIT_DELAY_MS);
+			regmap_read(regmaps[i], MAX310X_BRGDIVLSB_REG, &val);
+
+			if (val == 0x01)
+				started = true;
+		} while (!started && (++try < MAX310X_PORT_STARTUP_WAIT_RETRIES));
+
+		if (!started) {
+			ret = dev_err_probe(dev, -EAGAIN, "port reset failed\n");
+			goto out_uart;
+		}
 
-		regmap_write(s->regmap, MAX310X_MODE1_REG + offs,
-			     devtype->mode1);
+		regmap_write(regmaps[i], MAX310X_MODE1_REG, devtype->mode1);
 	}
 
 	uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
+	if (uartclk < 0) {
+		ret = uartclk;
+		goto out_uart;
+	}
+
 	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
 
 	for (i = 0; i < devtype->nr; i++) {
@@ -1346,11 +1406,13 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		s->p[i].port.fifosize	= MAX310X_FIFO_SIZE;
 		s->p[i].port.flags	= UPF_FIXED_TYPE | UPF_LOW_LATENCY;
 		s->p[i].port.iotype	= UPIO_PORT;
-		s->p[i].port.iobase	= i * 0x20;
+		s->p[i].port.iobase	= i;
 		s->p[i].port.membase	= (void __iomem *)~0;
 		s->p[i].port.uartclk	= uartclk;
 		s->p[i].port.rs485_config = max310x_rs485_config;
 		s->p[i].port.ops	= &max310x_ops;
+		s->p[i].regmap		= regmaps[i];
+
 		/* Disable all interrupts */
 		max310x_port_write(&s->p[i].port, MAX310X_IRQEN_REG, 0);
 		/* Clear IRQ status register */
@@ -1361,10 +1423,6 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
 		/* Initialize queue for changing RS485 mode */
 		INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
-		/* Initialize SPI-transfer buffers */
-		s->p[i].wr_header = (s->p[i].port.iobase + MAX310X_THR_REG) |
-				    MAX310X_WRITE_BIT;
-		s->p[i].rd_header = (s->p[i].port.iobase + MAX310X_RHR_REG);
 
 		/* Register port */
 		ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
@@ -1402,7 +1460,7 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 	if (!ret)
 		return 0;
 
-	dev_err(dev, "Unable to reguest IRQ %i\n", irq);
+	dev_err(dev, "Unable to request IRQ %i\n", irq);
 
 out_uart:
 	for (i = 0; i < devtype->nr; i++) {
@@ -1451,16 +1509,35 @@ static struct regmap_config regcfg = {
 	.val_bits = 8,
 	.write_flag_mask = MAX310X_WRITE_BIT,
 	.cache_type = REGCACHE_RBTREE,
+	.max_register = MAX310X_REG_1F,
 	.writeable_reg = max310x_reg_writeable,
 	.volatile_reg = max310x_reg_volatile,
 	.precious_reg = max310x_reg_precious,
+	.writeable_noinc_reg = max310x_reg_noinc,
+	.readable_noinc_reg = max310x_reg_noinc,
+	.max_raw_read = MAX310X_FIFO_SIZE,
+	.max_raw_write = MAX310X_FIFO_SIZE,
 };
 
 #ifdef CONFIG_SPI_MASTER
+static int max310x_spi_extended_reg_enable(struct device *dev, bool enable)
+{
+	struct max310x_port *s = dev_get_drvdata(dev);
+
+	return regmap_write(s->regmap, MAX310X_GLOBALCMD_REG,
+			    enable ? MAX310X_EXTREG_ENBL : MAX310X_EXTREG_DSBL);
+}
+
+static const struct max310x_if_cfg __maybe_unused max310x_spi_if_cfg = {
+	.extended_reg_enable = max310x_spi_extended_reg_enable,
+	.rev_id_reg = MAX310X_SPI_REVID_EXTREG,
+};
+
 static int max310x_spi_probe(struct spi_device *spi)
 {
-	struct max310x_devtype *devtype;
-	struct regmap *regmap;
+	const struct max310x_devtype *devtype;
+	struct regmap *regmaps[4];
+	unsigned int i;
 	int ret;
 
 	/* Setup SPI bus */
@@ -1471,23 +1548,18 @@ static int max310x_spi_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	if (spi->dev.of_node) {
-		const struct of_device_id *of_id =
-			of_match_device(max310x_dt_ids, &spi->dev);
-		if (!of_id)
-			return -ENODEV;
+	devtype = device_get_match_data(&spi->dev);
+	if (!devtype)
+		devtype = (struct max310x_devtype *)spi_get_device_id(spi)->driver_data;
 
-		devtype = (struct max310x_devtype *)of_id->data;
-	} else {
-		const struct spi_device_id *id_entry = spi_get_device_id(spi);
-
-		devtype = (struct max310x_devtype *)id_entry->driver_data;
+	for (i = 0; i < devtype->nr; i++) {
+		u8 port_mask = i * 0x20;
+		regcfg.read_flag_mask = port_mask;
+		regcfg.write_flag_mask = port_mask | MAX310X_WRITE_BIT;
+		regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
 	}
 
-	regcfg.max_register = devtype->nr * 0x20 - 1;
-	regmap = devm_regmap_init_spi(spi, &regcfg);
-
-	return max310x_probe(&spi->dev, devtype, regmap, spi->irq);
+	return max310x_probe(&spi->dev, devtype, &max310x_spi_if_cfg, regmaps, spi->irq);
 }
 
 static int max310x_spi_remove(struct spi_device *spi)
@@ -1507,7 +1579,7 @@ MODULE_DEVICE_TABLE(spi, max310x_id_table);
 static struct spi_driver max310x_spi_driver = {
 	.driver = {
 		.name		= MAX310X_NAME,
-		.of_match_table	= of_match_ptr(max310x_dt_ids),
+		.of_match_table	= max310x_dt_ids,
 		.pm		= &max310x_pm_ops,
 	},
 	.probe		= max310x_spi_probe,
@@ -1516,6 +1588,104 @@ static struct spi_driver max310x_spi_driver = {
 };
 #endif
 
+#ifdef CONFIG_I2C
+static int max310x_i2c_extended_reg_enable(struct device *dev, bool enable)
+{
+	return 0;
+}
+
+static struct regmap_config regcfg_i2c = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.cache_type = REGCACHE_RBTREE,
+	.writeable_reg = max310x_reg_writeable,
+	.volatile_reg = max310x_reg_volatile,
+	.precious_reg = max310x_reg_precious,
+	.max_register = MAX310X_I2C_REVID_EXTREG,
+	.writeable_noinc_reg = max310x_reg_noinc,
+	.readable_noinc_reg = max310x_reg_noinc,
+	.max_raw_read = MAX310X_FIFO_SIZE,
+	.max_raw_write = MAX310X_FIFO_SIZE,
+};
+
+static const struct max310x_if_cfg max310x_i2c_if_cfg = {
+	.extended_reg_enable = max310x_i2c_extended_reg_enable,
+	.rev_id_reg = MAX310X_I2C_REVID_EXTREG,
+};
+
+static unsigned short max310x_i2c_slave_addr(unsigned short addr,
+					     unsigned int nr)
+{
+	/*
+	 * For MAX14830 and MAX3109, the slave address depends on what the
+	 * A0 and A1 pins are tied to.
+	 * See Table I2C Address Map of the datasheet.
+	 * Based on that table, the following formulas were determined.
+	 * UART1 - UART0 = 0x10
+	 * UART2 - UART1 = 0x20 + 0x10
+	 * UART3 - UART2 = 0x10
+	 */
+
+	addr -= nr * 0x10;
+
+	if (nr >= 2)
+		addr -= 0x20;
+
+	return addr;
+}
+
+static int max310x_i2c_probe(struct i2c_client *client)
+{
+	const struct max310x_devtype *devtype;
+	struct i2c_client *port_client;
+	struct regmap *regmaps[4];
+	unsigned int i;
+	u8 port_addr;
+
+	devtype = device_get_match_data(&client->dev);
+	if (!devtype)
+		return dev_err_probe(&client->dev, -ENODEV, "Failed to match device\n");
+
+	if (client->addr < devtype->slave_addr.min ||
+		client->addr > devtype->slave_addr.max)
+		return dev_err_probe(&client->dev, -EINVAL,
+				     "Slave addr 0x%x outside of range [0x%x, 0x%x]\n",
+				     client->addr, devtype->slave_addr.min,
+				     devtype->slave_addr.max);
+
+	regmaps[0] = devm_regmap_init_i2c(client, &regcfg_i2c);
+
+	for (i = 1; i < devtype->nr; i++) {
+		port_addr = max310x_i2c_slave_addr(client->addr, i);
+		port_client = devm_i2c_new_dummy_device(&client->dev,
+							client->adapter,
+							port_addr);
+
+		regmaps[i] = devm_regmap_init_i2c(port_client, &regcfg_i2c);
+	}
+
+	return max310x_probe(&client->dev, devtype, &max310x_i2c_if_cfg,
+			     regmaps, client->irq);
+}
+
+static int max310x_i2c_remove(struct i2c_client *client)
+{
+	max310x_remove(&client->dev);
+
+	return 0;
+}
+
+static struct i2c_driver max310x_i2c_driver = {
+	.driver = {
+		.name		= MAX310X_NAME,
+		.of_match_table	= max310x_dt_ids,
+		.pm		= &max310x_pm_ops,
+	},
+	.probe_new	= max310x_i2c_probe,
+	.remove		= max310x_i2c_remove,
+};
+#endif
+
 static int __init max310x_uart_init(void)
 {
 	int ret;
@@ -1529,15 +1699,35 @@ static int __init max310x_uart_init(void)
 #ifdef CONFIG_SPI_MASTER
 	ret = spi_register_driver(&max310x_spi_driver);
 	if (ret)
-		uart_unregister_driver(&max310x_uart);
+		goto err_spi_register;
+#endif
+
+#ifdef CONFIG_I2C
+	ret = i2c_add_driver(&max310x_i2c_driver);
+	if (ret)
+		goto err_i2c_register;
+#endif
+
+	return 0;
+
+#ifdef CONFIG_I2C
+err_i2c_register:
+	spi_unregister_driver(&max310x_spi_driver);
 #endif
 
+err_spi_register:
+	uart_unregister_driver(&max310x_uart);
+
 	return ret;
 }
 module_init(max310x_uart_init);
 
 static void __exit max310x_uart_exit(void)
 {
+#ifdef CONFIG_I2C
+	i2c_del_driver(&max310x_i2c_driver);
+#endif
+
 #ifdef CONFIG_SPI_MASTER
 	spi_unregister_driver(&max310x_spi_driver);
 #endif
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index b784323a6..be6c8b9f1 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -1122,11 +1122,13 @@ static void mxs_auart_set_ldisc(struct uart_port *port,
 
 static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 {
-	u32 istat;
+	u32 istat, stat;
 	struct mxs_auart_port *s = context;
 	u32 mctrl_temp = s->mctrl_prev;
-	u32 stat = mxs_read(s, REG_STAT);
 
+	uart_port_lock(&s->port);
+
+	stat = mxs_read(s, REG_STAT);
 	istat = mxs_read(s, REG_INTR);
 
 	/* ack irq */
@@ -1162,6 +1164,8 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
 		istat &= ~AUART_INTR_TXIS;
 	}
 
+	uart_port_unlock(&s->port);
+
 	return IRQ_HANDLED;
 }
 
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index d6aef8a1f..1d0717fc3 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -217,7 +217,6 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap)
 {
 	struct tty_port *port;
 	unsigned char ch, r1, drop, flag;
-	int loops = 0;
 
 	/* Sanity check, make sure the old bug is no longer happening */
 	if (uap->port.state == NULL) {
@@ -298,25 +297,12 @@ static bool pmz_receive_chars(struct uart_pmac_port *uap)
 		if (r1 & Rx_OVR)
 			tty_insert_flip_char(port, 0, TTY_OVERRUN);
 	next_char:
-		/* We can get stuck in an infinite loop getting char 0 when the
-		 * line is in a wrong HW state, we break that here.
-		 * When that happens, I disable the receive side of the driver.
-		 * Note that what I've been experiencing is a real irq loop where
-		 * I'm getting flooded regardless of the actual port speed.
-		 * Something strange is going on with the HW
-		 */
-		if ((++loops) > 1000)
-			goto flood;
 		ch = read_zsreg(uap, R0);
 		if (!(ch & Rx_CH_AV))
 			break;
 	}
 
 	return true;
- flood:
-	pmz_interrupt_control(uap, 0);
-	pmz_error("pmz: rx irq flood !\n");
-	return true;
 }
 
 static void pmz_status_handle(struct uart_pmac_port *uap)
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index fa5b1321d..5388eb7fa 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -922,11 +922,10 @@ static unsigned int s3c24xx_serial_tx_empty(struct uart_port *port)
 		if ((ufstat & info->tx_fifomask) != 0 ||
 		    (ufstat & info->tx_fifofull))
 			return 0;
-
-		return 1;
+		return TIOCSER_TEMT;
 	}
 
-	return s3c24xx_serial_txempty_nofifo(port);
+	return s3c24xx_serial_txempty_nofifo(port) ? TIOCSER_TEMT : 0;
 }
 
 /* no modem control lines */
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index fd9be81bc..29f05db0d 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -24,6 +24,7 @@
 #include <linux/tty_flip.h>
 #include <linux/spi/spi.h>
 #include <linux/uaccess.h>
+#include <linux/units.h>
 #include <uapi/linux/sched/types.h>
 
 #define SC16IS7XX_NAME			"sc16is7xx"
@@ -375,9 +376,7 @@ static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
 	const u8 line = sc16is7xx_line(port);
 	u8 addr = (SC16IS7XX_RHR_REG << SC16IS7XX_REG_SHIFT) | line;
 
-	regcache_cache_bypass(s->regmap, true);
-	regmap_raw_read(s->regmap, addr, s->buf, rxlen);
-	regcache_cache_bypass(s->regmap, false);
+	regmap_noinc_read(s->regmap, addr, s->buf, rxlen);
 }
 
 static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
@@ -393,9 +392,7 @@ static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
 	if (unlikely(!to_send))
 		return;
 
-	regcache_cache_bypass(s->regmap, true);
-	regmap_raw_write(s->regmap, addr, s->buf, to_send);
-	regcache_cache_bypass(s->regmap, false);
+	regmap_noinc_write(s->regmap, addr, s->buf, to_send);
 }
 
 static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
@@ -488,6 +485,11 @@ static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
 	return false;
 }
 
+static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
+{
+	return reg == SC16IS7XX_RHR_REG;
+}
+
 static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 {
 	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
@@ -1438,6 +1440,8 @@ static struct regmap_config regcfg = {
 	.cache_type = REGCACHE_RBTREE,
 	.volatile_reg = sc16is7xx_regmap_volatile,
 	.precious_reg = sc16is7xx_regmap_precious,
+	.writeable_noinc_reg = sc16is7xx_regmap_noinc,
+	.readable_noinc_reg = sc16is7xx_regmap_noinc,
 };
 
 #ifdef CONFIG_SERIAL_SC16IS7XX_SPI
@@ -1449,9 +1453,12 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
 
 	/* Setup SPI bus */
 	spi->bits_per_word	= 8;
-	/* only supports mode 0 on SC16IS762 */
+	/* For all variants, only mode 0 is supported */
+	if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
+		return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
+
 	spi->mode		= spi->mode ? : SPI_MODE_0;
-	spi->max_speed_hz	= spi->max_speed_hz ? : 15000000;
+	spi->max_speed_hz	= spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
 	ret = spi_setup(spi);
 	if (ret)
 		return ret;
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 40fff3858..10b8785b9 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2431,7 +2431,12 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 			port->type = PORT_UNKNOWN;
 			flags |= UART_CONFIG_TYPE;
 		}
+		/* Synchronize with possible boot console. */
+		if (uart_console(port))
+			console_lock();
 		port->ops->config_port(port, flags);
+		if (uart_console(port))
+			console_unlock();
 	}
 
 	if (port->type != PORT_UNKNOWN) {
@@ -2439,6 +2444,10 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 
 		uart_report_port(drv, port);
 
+		/* Synchronize with possible boot console. */
+		if (uart_console(port))
+			console_lock();
+
 		/* Power up port for set_mctrl() */
 		uart_change_pm(state, UART_PM_STATE_ON);
 
@@ -2455,6 +2464,9 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 			port->rs485_config(port, &port->rs485);
 		spin_unlock_irqrestore(&port->lock, flags);
 
+		if (uart_console(port))
+			console_unlock();
+
 		/*
 		 * If this driver supports console, and it hasn't been
 		 * successfully registered yet, try to re-register it.