Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 953 insertions, 0 deletions

diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
new file mode 100644
index 0000000000..3adb60c683
--- /dev/null
+++ b/drivers/tty/serial/lantiq.c
@@ -0,0 +1,953 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ * Copyright (C) 2004 Infineon IFAP DC COM CPE
+ * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2007 John Crispin <john@phrozen.org>
+ * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/lantiq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define PORT_LTQ_ASC		111
+#define MAXPORTS		2
+#define UART_DUMMY_UER_RX	1
+#define DRVNAME			"lantiq,asc"
+#ifdef __BIG_ENDIAN
+#define LTQ_ASC_TBUF		(0x0020 + 3)
+#define LTQ_ASC_RBUF		(0x0024 + 3)
+#else
+#define LTQ_ASC_TBUF		0x0020
+#define LTQ_ASC_RBUF		0x0024
+#endif
+#define LTQ_ASC_FSTAT		0x0048
+#define LTQ_ASC_WHBSTATE	0x0018
+#define LTQ_ASC_STATE		0x0014
+#define LTQ_ASC_IRNCR		0x00F8
+#define LTQ_ASC_CLC		0x0000
+#define LTQ_ASC_ID		0x0008
+#define LTQ_ASC_PISEL		0x0004
+#define LTQ_ASC_TXFCON		0x0044
+#define LTQ_ASC_RXFCON		0x0040
+#define LTQ_ASC_CON		0x0010
+#define LTQ_ASC_BG		0x0050
+#define LTQ_ASC_IRNREN		0x00F4
+
+#define ASC_IRNREN_TX		0x1
+#define ASC_IRNREN_RX		0x2
+#define ASC_IRNREN_ERR		0x4
+#define ASC_IRNREN_TX_BUF	0x8
+#define ASC_IRNCR_TIR		0x1
+#define ASC_IRNCR_RIR		0x2
+#define ASC_IRNCR_EIR		0x4
+#define ASC_IRNCR_MASK		GENMASK(2, 0)
+
+#define ASCOPT_CSIZE		0x3
+#define TXFIFO_FL		1
+#define RXFIFO_FL		1
+#define ASCCLC_DISS		0x2
+#define ASCCLC_RMCMASK		0x0000FF00
+#define ASCCLC_RMCOFFSET	8
+#define ASCCON_M_8ASYNC		0x0
+#define ASCCON_M_7ASYNC		0x2
+#define ASCCON_ODD		0x00000020
+#define ASCCON_STP		0x00000080
+#define ASCCON_BRS		0x00000100
+#define ASCCON_FDE		0x00000200
+#define ASCCON_R		0x00008000
+#define ASCCON_FEN		0x00020000
+#define ASCCON_ROEN		0x00080000
+#define ASCCON_TOEN		0x00100000
+#define ASCSTATE_PE		0x00010000
+#define ASCSTATE_FE		0x00020000
+#define ASCSTATE_ROE		0x00080000
+#define ASCSTATE_ANY		(ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE)
+#define ASCWHBSTATE_CLRREN	0x00000001
+#define ASCWHBSTATE_SETREN	0x00000002
+#define ASCWHBSTATE_CLRPE	0x00000004
+#define ASCWHBSTATE_CLRFE	0x00000008
+#define ASCWHBSTATE_CLRROE	0x00000020
+#define ASCTXFCON_TXFEN		0x0001
+#define ASCTXFCON_TXFFLU	0x0002
+#define ASCTXFCON_TXFITLMASK	0x3F00
+#define ASCTXFCON_TXFITLOFF	8
+#define ASCRXFCON_RXFEN		0x0001
+#define ASCRXFCON_RXFFLU	0x0002
+#define ASCRXFCON_RXFITLMASK	0x3F00
+#define ASCRXFCON_RXFITLOFF	8
+#define ASCFSTAT_RXFFLMASK	0x003F
+#define ASCFSTAT_TXFFLMASK	0x3F00
+#define ASCFSTAT_TXFREEMASK	0x3F000000
+
+static struct ltq_uart_port *lqasc_port[MAXPORTS];
+static struct uart_driver lqasc_reg;
+
+struct ltq_soc_data {
+	int	(*fetch_irq)(struct device *dev, struct ltq_uart_port *ltq_port);
+	int	(*request_irq)(struct uart_port *port);
+	void	(*free_irq)(struct uart_port *port);
+};
+
+struct ltq_uart_port {
+	struct uart_port	port;
+	/* clock used to derive divider */
+	struct clk		*freqclk;
+	/* clock gating of the ASC core */
+	struct clk		*clk;
+	unsigned int		tx_irq;
+	unsigned int		rx_irq;
+	unsigned int		err_irq;
+	unsigned int		common_irq;
+	spinlock_t		lock; /* exclusive access for multi core */
+
+	const struct ltq_soc_data	*soc;
+};
+
+static inline void asc_update_bits(u32 clear, u32 set, void __iomem *reg)
+{
+	u32 tmp = __raw_readl(reg);
+
+	__raw_writel((tmp & ~clear) | set, reg);
+}
+
+static inline struct
+ltq_uart_port *to_ltq_uart_port(struct uart_port *port)
+{
+	return container_of(port, struct ltq_uart_port, port);
+}
+
+static void
+lqasc_stop_tx(struct uart_port *port)
+{
+	return;
+}
+
+static bool lqasc_tx_ready(struct uart_port *port)
+{
+	u32 fstat = __raw_readl(port->membase + LTQ_ASC_FSTAT);
+
+	return FIELD_GET(ASCFSTAT_TXFREEMASK, fstat);
+}
+
+static void
+lqasc_start_tx(struct uart_port *port)
+{
+	unsigned long flags;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	u8 ch;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	uart_port_tx(port, ch,
+		lqasc_tx_ready(port),
+		writeb(ch, port->membase + LTQ_ASC_TBUF));
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	return;
+}
+
+static void
+lqasc_stop_rx(struct uart_port *port)
+{
+	__raw_writel(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE);
+}
+
+static int
+lqasc_rx_chars(struct uart_port *port)
+{
+	struct tty_port *tport = &port->state->port;
+	unsigned int ch = 0, rsr = 0, fifocnt;
+
+	fifocnt = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
+		  ASCFSTAT_RXFFLMASK;
+	while (fifocnt--) {
+		u8 flag = TTY_NORMAL;
+		ch = readb(port->membase + LTQ_ASC_RBUF);
+		rsr = (__raw_readl(port->membase + LTQ_ASC_STATE)
+			& ASCSTATE_ANY) | UART_DUMMY_UER_RX;
+		tty_flip_buffer_push(tport);
+		port->icount.rx++;
+
+		/*
+		 * Note that the error handling code is
+		 * out of the main execution path
+		 */
+		if (rsr & ASCSTATE_ANY) {
+			if (rsr & ASCSTATE_PE) {
+				port->icount.parity++;
+				asc_update_bits(0, ASCWHBSTATE_CLRPE,
+					port->membase + LTQ_ASC_WHBSTATE);
+			} else if (rsr & ASCSTATE_FE) {
+				port->icount.frame++;
+				asc_update_bits(0, ASCWHBSTATE_CLRFE,
+					port->membase + LTQ_ASC_WHBSTATE);
+			}
+			if (rsr & ASCSTATE_ROE) {
+				port->icount.overrun++;
+				asc_update_bits(0, ASCWHBSTATE_CLRROE,
+					port->membase + LTQ_ASC_WHBSTATE);
+			}
+
+			rsr &= port->read_status_mask;
+
+			if (rsr & ASCSTATE_PE)
+				flag = TTY_PARITY;
+			else if (rsr & ASCSTATE_FE)
+				flag = TTY_FRAME;
+		}
+
+		if ((rsr & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tport, ch, flag);
+
+		if (rsr & ASCSTATE_ROE)
+			/*
+			 * Overrun is special, since it's reported
+			 * immediately, and doesn't affect the current
+			 * character
+			 */
+			tty_insert_flip_char(tport, 0, TTY_OVERRUN);
+	}
+
+	if (ch != 0)
+		tty_flip_buffer_push(tport);
+
+	return 0;
+}
+
+static irqreturn_t
+lqasc_tx_int(int irq, void *_port)
+{
+	unsigned long flags;
+	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	lqasc_start_tx(port);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t
+lqasc_err_int(int irq, void *_port)
+{
+	unsigned long flags;
+	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
+	/* clear any pending interrupts */
+	asc_update_bits(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE |
+		ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t
+lqasc_rx_int(int irq, void *_port)
+{
+	unsigned long flags;
+	struct uart_port *port = (struct uart_port *)_port;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
+	lqasc_rx_chars(port);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t lqasc_irq(int irq, void *p)
+{
+	unsigned long flags;
+	u32 stat;
+	struct uart_port *port = p;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	stat = readl(port->membase + LTQ_ASC_IRNCR);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	if (!(stat & ASC_IRNCR_MASK))
+		return IRQ_NONE;
+
+	if (stat & ASC_IRNCR_TIR)
+		lqasc_tx_int(irq, p);
+
+	if (stat & ASC_IRNCR_RIR)
+		lqasc_rx_int(irq, p);
+
+	if (stat & ASC_IRNCR_EIR)
+		lqasc_err_int(irq, p);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int
+lqasc_tx_empty(struct uart_port *port)
+{
+	int status;
+	status = __raw_readl(port->membase + LTQ_ASC_FSTAT) &
+		 ASCFSTAT_TXFFLMASK;
+	return status ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int
+lqasc_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR;
+}
+
+static void
+lqasc_set_mctrl(struct uart_port *port, u_int mctrl)
+{
+}
+
+static void
+lqasc_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int
+lqasc_startup(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	int retval;
+	unsigned long flags;
+
+	if (!IS_ERR(ltq_port->clk))
+		clk_prepare_enable(ltq_port->clk);
+	port->uartclk = clk_get_rate(ltq_port->freqclk);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	asc_update_bits(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
+		port->membase + LTQ_ASC_CLC);
+
+	__raw_writel(0, port->membase + LTQ_ASC_PISEL);
+	__raw_writel(
+		((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) |
+		ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
+		port->membase + LTQ_ASC_TXFCON);
+	__raw_writel(
+		((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK)
+		| ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
+		port->membase + LTQ_ASC_RXFCON);
+	/* make sure other settings are written to hardware before
+	 * setting enable bits
+	 */
+	wmb();
+	asc_update_bits(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN |
+		ASCCON_ROEN, port->membase + LTQ_ASC_CON);
+
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+
+	retval = ltq_port->soc->request_irq(port);
+	if (retval)
+		return retval;
+
+	__raw_writel(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX,
+		port->membase + LTQ_ASC_IRNREN);
+	return retval;
+}
+
+static void
+lqasc_shutdown(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	unsigned long flags;
+
+	ltq_port->soc->free_irq(port);
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	__raw_writel(0, port->membase + LTQ_ASC_CON);
+	asc_update_bits(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU,
+		port->membase + LTQ_ASC_RXFCON);
+	asc_update_bits(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
+		port->membase + LTQ_ASC_TXFCON);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+	if (!IS_ERR(ltq_port->clk))
+		clk_disable_unprepare(ltq_port->clk);
+}
+
+static void
+lqasc_set_termios(struct uart_port *port, struct ktermios *new,
+		  const struct ktermios *old)
+{
+	unsigned int cflag;
+	unsigned int iflag;
+	unsigned int divisor;
+	unsigned int baud;
+	unsigned int con = 0;
+	unsigned long flags;
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	cflag = new->c_cflag;
+	iflag = new->c_iflag;
+
+	switch (cflag & CSIZE) {
+	case CS7:
+		con = ASCCON_M_7ASYNC;
+		break;
+
+	case CS5:
+	case CS6:
+	default:
+		new->c_cflag &= ~ CSIZE;
+		new->c_cflag |= CS8;
+		con = ASCCON_M_8ASYNC;
+		break;
+	}
+
+	cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
+
+	if (cflag & CSTOPB)
+		con |= ASCCON_STP;
+
+	if (cflag & PARENB) {
+		if (!(cflag & PARODD))
+			con &= ~ASCCON_ODD;
+		else
+			con |= ASCCON_ODD;
+	}
+
+	port->read_status_mask = ASCSTATE_ROE;
+	if (iflag & INPCK)
+		port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
+
+	port->ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE;
+
+	if (iflag & IGNBRK) {
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (iflag & IGNPAR)
+			port->ignore_status_mask |= ASCSTATE_ROE;
+	}
+
+	if ((cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_DUMMY_UER_RX;
+
+	/* set error signals  - framing, parity  and overrun, enable receiver */
+	con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+
+	/* set up CON */
+	asc_update_bits(0, con, port->membase + LTQ_ASC_CON);
+
+	/* Set baud rate - take a divider of 2 into account */
+	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+	divisor = uart_get_divisor(port, baud);
+	divisor = divisor / 2 - 1;
+
+	/* disable the baudrate generator */
+	asc_update_bits(ASCCON_R, 0, port->membase + LTQ_ASC_CON);
+
+	/* make sure the fractional divider is off */
+	asc_update_bits(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON);
+
+	/* set up to use divisor of 2 */
+	asc_update_bits(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON);
+
+	/* now we can write the new baudrate into the register */
+	__raw_writel(divisor, port->membase + LTQ_ASC_BG);
+
+	/* turn the baudrate generator back on */
+	asc_update_bits(0, ASCCON_R, port->membase + LTQ_ASC_CON);
+
+	/* enable rx */
+	__raw_writel(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE);
+
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(new))
+		tty_termios_encode_baud_rate(new, baud, baud);
+
+	uart_update_timeout(port, cflag, baud);
+}
+
+static const char*
+lqasc_type(struct uart_port *port)
+{
+	if (port->type == PORT_LTQ_ASC)
+		return DRVNAME;
+	else
+		return NULL;
+}
+
+static void
+lqasc_release_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+
+	if (port->flags & UPF_IOREMAP) {
+		devm_iounmap(&pdev->dev, port->membase);
+		port->membase = NULL;
+	}
+}
+
+static int
+lqasc_request_port(struct uart_port *port)
+{
+	struct platform_device *pdev = to_platform_device(port->dev);
+	struct resource *res;
+	int size;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "cannot obtain I/O memory region");
+		return -ENODEV;
+	}
+	size = resource_size(res);
+
+	res = devm_request_mem_region(&pdev->dev, res->start,
+		size, dev_name(&pdev->dev));
+	if (!res) {
+		dev_err(&pdev->dev, "cannot request I/O memory region");
+		return -EBUSY;
+	}
+
+	if (port->flags & UPF_IOREMAP) {
+		port->membase = devm_ioremap(&pdev->dev,
+			port->mapbase, size);
+		if (port->membase == NULL)
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+static void
+lqasc_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		port->type = PORT_LTQ_ASC;
+		lqasc_request_port(port);
+	}
+}
+
+static int
+lqasc_verify_port(struct uart_port *port,
+	struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC)
+		ret = -EINVAL;
+	if (ser->irq < 0 || ser->irq >= NR_IRQS)
+		ret = -EINVAL;
+	if (ser->baud_base < 9600)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops lqasc_pops = {
+	.tx_empty =	lqasc_tx_empty,
+	.set_mctrl =	lqasc_set_mctrl,
+	.get_mctrl =	lqasc_get_mctrl,
+	.stop_tx =	lqasc_stop_tx,
+	.start_tx =	lqasc_start_tx,
+	.stop_rx =	lqasc_stop_rx,
+	.break_ctl =	lqasc_break_ctl,
+	.startup =	lqasc_startup,
+	.shutdown =	lqasc_shutdown,
+	.set_termios =	lqasc_set_termios,
+	.type =		lqasc_type,
+	.release_port =	lqasc_release_port,
+	.request_port =	lqasc_request_port,
+	.config_port =	lqasc_config_port,
+	.verify_port =	lqasc_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_LANTIQ_CONSOLE
+static void
+lqasc_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	if (!port->membase)
+		return;
+
+	while (!lqasc_tx_ready(port))
+		;
+
+	writeb(ch, port->membase + LTQ_ASC_TBUF);
+}
+
+static void lqasc_serial_port_write(struct uart_port *port, const char *s,
+				    u_int count)
+{
+	uart_console_write(port, s, count, lqasc_console_putchar);
+}
+
+static void
+lqasc_console_write(struct console *co, const char *s, u_int count)
+{
+	struct ltq_uart_port *ltq_port;
+	unsigned long flags;
+
+	if (co->index >= MAXPORTS)
+		return;
+
+	ltq_port = lqasc_port[co->index];
+	if (!ltq_port)
+		return;
+
+	spin_lock_irqsave(&ltq_port->lock, flags);
+	lqasc_serial_port_write(&ltq_port->port, s, count);
+	spin_unlock_irqrestore(&ltq_port->lock, flags);
+}
+
+static int __init
+lqasc_console_setup(struct console *co, char *options)
+{
+	struct ltq_uart_port *ltq_port;
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= MAXPORTS)
+		return -ENODEV;
+
+	ltq_port = lqasc_port[co->index];
+	if (!ltq_port)
+		return -ENODEV;
+
+	port = &ltq_port->port;
+
+	if (!IS_ERR(ltq_port->clk))
+		clk_prepare_enable(ltq_port->clk);
+
+	port->uartclk = clk_get_rate(ltq_port->freqclk);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console lqasc_console = {
+	.name =		"ttyLTQ",
+	.write =	lqasc_console_write,
+	.device =	uart_console_device,
+	.setup =	lqasc_console_setup,
+	.flags =	CON_PRINTBUFFER,
+	.index =	-1,
+	.data =		&lqasc_reg,
+};
+
+static int __init
+lqasc_console_init(void)
+{
+	register_console(&lqasc_console);
+	return 0;
+}
+console_initcall(lqasc_console_init);
+
+static void lqasc_serial_early_console_write(struct console *co,
+					     const char *s,
+					     u_int count)
+{
+	struct earlycon_device *dev = co->data;
+
+	lqasc_serial_port_write(&dev->port, s, count);
+}
+
+static int __init
+lqasc_serial_early_console_setup(struct earlycon_device *device,
+				 const char *opt)
+{
+	if (!device->port.membase)
+		return -ENODEV;
+
+	device->con->write = lqasc_serial_early_console_write;
+	return 0;
+}
+OF_EARLYCON_DECLARE(lantiq, "lantiq,asc", lqasc_serial_early_console_setup);
+OF_EARLYCON_DECLARE(lantiq, "intel,lgm-asc", lqasc_serial_early_console_setup);
+
+#define LANTIQ_SERIAL_CONSOLE	(&lqasc_console)
+
+#else
+
+#define LANTIQ_SERIAL_CONSOLE	NULL
+
+#endif /* CONFIG_SERIAL_LANTIQ_CONSOLE */
+
+static struct uart_driver lqasc_reg = {
+	.owner =	THIS_MODULE,
+	.driver_name =	DRVNAME,
+	.dev_name =	"ttyLTQ",
+	.major =	0,
+	.minor =	0,
+	.nr =		MAXPORTS,
+	.cons =		LANTIQ_SERIAL_CONSOLE,
+};
+
+static int fetch_irq_lantiq(struct device *dev, struct ltq_uart_port *ltq_port)
+{
+	struct uart_port *port = &ltq_port->port;
+	struct platform_device *pdev = to_platform_device(dev);
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+	ltq_port->tx_irq = irq;
+	irq = platform_get_irq(pdev, 1);
+	if (irq < 0)
+		return irq;
+	ltq_port->rx_irq = irq;
+	irq = platform_get_irq(pdev, 2);
+	if (irq < 0)
+		return irq;
+	ltq_port->err_irq = irq;
+
+	port->irq = ltq_port->tx_irq;
+
+	return 0;
+}
+
+static int request_irq_lantiq(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	int retval;
+
+	retval = request_irq(ltq_port->tx_irq, lqasc_tx_int,
+			     0, "asc_tx", port);
+	if (retval) {
+		dev_err(port->dev, "failed to request asc_tx\n");
+		return retval;
+	}
+
+	retval = request_irq(ltq_port->rx_irq, lqasc_rx_int,
+			     0, "asc_rx", port);
+	if (retval) {
+		dev_err(port->dev, "failed to request asc_rx\n");
+		goto err1;
+	}
+
+	retval = request_irq(ltq_port->err_irq, lqasc_err_int,
+			     0, "asc_err", port);
+	if (retval) {
+		dev_err(port->dev, "failed to request asc_err\n");
+		goto err2;
+	}
+	return 0;
+
+err2:
+	free_irq(ltq_port->rx_irq, port);
+err1:
+	free_irq(ltq_port->tx_irq, port);
+	return retval;
+}
+
+static void free_irq_lantiq(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	free_irq(ltq_port->tx_irq, port);
+	free_irq(ltq_port->rx_irq, port);
+	free_irq(ltq_port->err_irq, port);
+}
+
+static int fetch_irq_intel(struct device *dev, struct ltq_uart_port *ltq_port)
+{
+	struct uart_port *port = &ltq_port->port;
+	int ret;
+
+	ret = platform_get_irq(to_platform_device(dev), 0);
+	if (ret < 0) {
+		dev_err(dev, "failed to fetch IRQ for serial port\n");
+		return ret;
+	}
+	ltq_port->common_irq = ret;
+	port->irq = ret;
+
+	return 0;
+}
+
+static int request_irq_intel(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+	int retval;
+
+	retval = request_irq(ltq_port->common_irq, lqasc_irq, 0,
+			     "asc_irq", port);
+	if (retval)
+		dev_err(port->dev, "failed to request asc_irq\n");
+
+	return retval;
+}
+
+static void free_irq_intel(struct uart_port *port)
+{
+	struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
+
+	free_irq(ltq_port->common_irq, port);
+}
+
+static int lqasc_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct ltq_uart_port *ltq_port;
+	struct uart_port *port;
+	struct resource *mmres;
+	int line;
+	int ret;
+
+	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mmres) {
+		dev_err(&pdev->dev,
+			"failed to get memory for serial port\n");
+		return -ENODEV;
+	}
+
+	ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
+				GFP_KERNEL);
+	if (!ltq_port)
+		return -ENOMEM;
+
+	port = &ltq_port->port;
+
+	ltq_port->soc = of_device_get_match_data(&pdev->dev);
+	ret = ltq_port->soc->fetch_irq(&pdev->dev, ltq_port);
+	if (ret)
+		return ret;
+
+	/* get serial id */
+	line = of_alias_get_id(node, "serial");
+	if (line < 0) {
+		if (IS_ENABLED(CONFIG_LANTIQ)) {
+			if (mmres->start == CPHYSADDR(LTQ_EARLY_ASC))
+				line = 0;
+			else
+				line = 1;
+		} else {
+			dev_err(&pdev->dev, "failed to get alias id, errno %d\n",
+				line);
+			return line;
+		}
+	}
+
+	if (lqasc_port[line]) {
+		dev_err(&pdev->dev, "port %d already allocated\n", line);
+		return -EBUSY;
+	}
+
+	port->iotype	= SERIAL_IO_MEM;
+	port->flags	= UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+	port->ops	= &lqasc_pops;
+	port->fifosize	= 16;
+	port->type	= PORT_LTQ_ASC;
+	port->line	= line;
+	port->dev	= &pdev->dev;
+	/* unused, just to be backward-compatible */
+	port->mapbase	= mmres->start;
+
+	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
+		ltq_port->freqclk = clk_get_fpi();
+	else
+		ltq_port->freqclk = devm_clk_get(&pdev->dev, "freq");
+
+
+	if (IS_ERR(ltq_port->freqclk)) {
+		pr_err("failed to get fpi clk\n");
+		return -ENOENT;
+	}
+
+	/* not all asc ports have clock gates, lets ignore the return code */
+	if (IS_ENABLED(CONFIG_LANTIQ) && !IS_ENABLED(CONFIG_COMMON_CLK))
+		ltq_port->clk = clk_get(&pdev->dev, NULL);
+	else
+		ltq_port->clk = devm_clk_get(&pdev->dev, "asc");
+
+	spin_lock_init(&ltq_port->lock);
+	lqasc_port[line] = ltq_port;
+	platform_set_drvdata(pdev, ltq_port);
+
+	ret = uart_add_one_port(&lqasc_reg, port);
+
+	return ret;
+}
+
+static int lqasc_remove(struct platform_device *pdev)
+{
+	struct uart_port *port = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&lqasc_reg, port);
+
+	return 0;
+}
+
+static const struct ltq_soc_data soc_data_lantiq = {
+	.fetch_irq = fetch_irq_lantiq,
+	.request_irq = request_irq_lantiq,
+	.free_irq = free_irq_lantiq,
+};
+
+static const struct ltq_soc_data soc_data_intel = {
+	.fetch_irq = fetch_irq_intel,
+	.request_irq = request_irq_intel,
+	.free_irq = free_irq_intel,
+};
+
+static const struct of_device_id ltq_asc_match[] = {
+	{ .compatible = "lantiq,asc", .data = &soc_data_lantiq },
+	{ .compatible = "intel,lgm-asc", .data = &soc_data_intel },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ltq_asc_match);
+
+static struct platform_driver lqasc_driver = {
+	.probe		= lqasc_probe,
+	.remove		= lqasc_remove,
+	.driver		= {
+		.name	= DRVNAME,
+		.of_match_table = ltq_asc_match,
+	},
+};
+
+static int __init
+init_lqasc(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&lqasc_reg);
+	if (ret != 0)
+		return ret;
+
+	ret = platform_driver_register(&lqasc_driver);
+	if (ret != 0)
+		uart_unregister_driver(&lqasc_reg);
+
+	return ret;
+}
+
+static void __exit exit_lqasc(void)
+{
+	platform_driver_unregister(&lqasc_driver);
+	uart_unregister_driver(&lqasc_reg);
+}
+
+module_init(init_lqasc);
+module_exit(exit_lqasc);
+
+MODULE_DESCRIPTION("Serial driver for Lantiq & Intel gateway SoCs");
+MODULE_LICENSE("GPL v2");