drivers/tty/serial/8250/8250_fintek.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  Probe for F81216A LPC to 4 UART
  *
  *  Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
  */
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/pnp.h>
 #include <linux/kernel.h>
 #include <linux/serial_core.h>
 #include <linux/irq.h>
 #include  "8250.h"

 #define ADDR_PORT 0
 #define DATA_PORT 1
 #define EXIT_KEY 0xAA
 #define CHIP_ID1  0x20
 #define CHIP_ID2  0x21
 #define CHIP_ID_F81865 0x0407
 #define CHIP_ID_F81866 0x1010
 #define CHIP_ID_F81966 0x0215
 #define CHIP_ID_F81216AD 0x1602
 #define CHIP_ID_F81216H 0x0501
 #define CHIP_ID_F81216 0x0802
 #define VENDOR_ID1 0x23
 #define VENDOR_ID1_VAL 0x19
 #define VENDOR_ID2 0x24
 #define VENDOR_ID2_VAL 0x34
 #define IO_ADDR1 0x61
 #define IO_ADDR2 0x60
 #define LDN 0x7

 #define FINTEK_IRQ_MODE	0x70
 #define IRQ_SHARE	BIT(4)
 #define IRQ_MODE_MASK	(BIT(6) | BIT(5))
 #define IRQ_LEVEL_LOW	0
 #define IRQ_EDGE_HIGH	BIT(5)

 /*
  * F81216H clock source register, the value and mask is the same with F81866,
  * but it's on F0h.
  *
  * Clock speeds for UART (register F0h)
  * 00: 1.8432MHz.
  * 01: 18.432MHz.
  * 10: 24MHz.
  * 11: 14.769MHz.
  */
 #define RS485  0xF0
 #define RTS_INVERT BIT(5)
 #define RS485_URA BIT(4)
 #define RXW4C_IRA BIT(3)
 #define TXW4C_IRA BIT(2)

 #define FIFO_CTRL		0xF6
 #define FIFO_MODE_MASK		(BIT(1) | BIT(0))
 #define FIFO_MODE_128		(BIT(1) | BIT(0))
 #define RXFTHR_MODE_MASK	(BIT(5) | BIT(4))
 #define RXFTHR_MODE_4X		BIT(5)

 #define F81216_LDN_LOW	0x0
 #define F81216_LDN_HIGH	0x4

 /*
  * F81866/966 registers
  *
  * The IRQ setting mode of F81866/966 is not the same with F81216 series.
  *	Level/Low: IRQ_MODE0:0, IRQ_MODE1:0
  *	Edge/High: IRQ_MODE0:1, IRQ_MODE1:0
  *
  * Clock speeds for UART (register F2h)
  * 00: 1.8432MHz.
  * 01: 18.432MHz.
  * 10: 24MHz.
  * 11: 14.769MHz.
  */
 #define F81866_IRQ_MODE		0xf0
 #define F81866_IRQ_SHARE	BIT(0)
 #define F81866_IRQ_MODE0	BIT(1)

 #define F81866_FIFO_CTRL	FIFO_CTRL
 #define F81866_IRQ_MODE1	BIT(3)

 #define F81866_LDN_LOW		0x10
 #define F81866_LDN_HIGH		0x16

 #define F81866_UART_CLK 0xF2
 #define F81866_UART_CLK_MASK (BIT(1) | BIT(0))
 #define F81866_UART_CLK_1_8432MHZ 0
 #define F81866_UART_CLK_14_769MHZ (BIT(1) | BIT(0))
 #define F81866_UART_CLK_18_432MHZ BIT(0)
 #define F81866_UART_CLK_24MHZ BIT(1)

 struct fintek_8250 {
 	u16 pid;
 	u16 base_port;
 	u8 index;
 	u8 key;
 };

 static u8 sio_read_reg(struct fintek_8250 *pdata, u8 reg)
 {
 	outb(reg, pdata->base_port + ADDR_PORT);
 	return inb(pdata->base_port + DATA_PORT);
 }

 static void sio_write_reg(struct fintek_8250 *pdata, u8 reg, u8 data)
 {
 	outb(reg, pdata->base_port + ADDR_PORT);
 	outb(data, pdata->base_port + DATA_PORT);
 }

 static void sio_write_mask_reg(struct fintek_8250 *pdata, u8 reg, u8 mask,
 			       u8 data)
 {
 	u8 tmp;

 	tmp = (sio_read_reg(pdata, reg) & ~mask) | (mask & data);
 	sio_write_reg(pdata, reg, tmp);
 }

 static int fintek_8250_enter_key(u16 base_port, u8 key)
 {
 	if (!request_muxed_region(base_port, 2, "8250_fintek"))
 		return -EBUSY;

 	/* Force to deactive all SuperIO in this base_port */
 	outb(EXIT_KEY, base_port + ADDR_PORT);

 	outb(key, base_port + ADDR_PORT);
 	outb(key, base_port + ADDR_PORT);
 	return 0;
 }

 static void fintek_8250_exit_key(u16 base_port)
 {

 	outb(EXIT_KEY, base_port + ADDR_PORT);
 	release_region(base_port + ADDR_PORT, 2);
 }

 static int fintek_8250_check_id(struct fintek_8250 *pdata)
 {
 	u16 chip;

 	if (sio_read_reg(pdata, VENDOR_ID1) != VENDOR_ID1_VAL)
 		return -ENODEV;

 	if (sio_read_reg(pdata, VENDOR_ID2) != VENDOR_ID2_VAL)
 		return -ENODEV;

 	chip = sio_read_reg(pdata, CHIP_ID1);
 	chip |= sio_read_reg(pdata, CHIP_ID2) << 8;

 	switch (chip) {
 	case CHIP_ID_F81865:
 	case CHIP_ID_F81866:
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81216AD:
 	case CHIP_ID_F81216H:
 	case CHIP_ID_F81216:
 		break;
 	default:
 		return -ENODEV;
 	}

 	pdata->pid = chip;
 	return 0;
 }

 static int fintek_8250_get_ldn_range(struct fintek_8250 *pdata, int *min,
 				     int *max)
 {
 	switch (pdata->pid) {
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81865:
 	case CHIP_ID_F81866:
 		*min = F81866_LDN_LOW;
 		*max = F81866_LDN_HIGH;
 		return 0;

 	case CHIP_ID_F81216AD:
 	case CHIP_ID_F81216H:
 	case CHIP_ID_F81216:
 		*min = F81216_LDN_LOW;
 		*max = F81216_LDN_HIGH;
 		return 0;
 	}

 	return -ENODEV;
 }

 static int fintek_8250_rs485_config(struct uart_port *port,
 			      struct serial_rs485 *rs485)
 {
 	uint8_t config = 0;
 	struct fintek_8250 *pdata = port->private_data;

 	if (!pdata)
 		return -EINVAL;

 	/* Hardware do not support same RTS level on send and receive */
 	if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
 			!(rs485->flags & SER_RS485_RTS_AFTER_SEND))
 		return -EINVAL;

 	if (rs485->flags & SER_RS485_ENABLED) {
 		memset(rs485->padding, 0, sizeof(rs485->padding));
 		config |= RS485_URA;
 	} else {
 		memset(rs485, 0, sizeof(*rs485));
 	}

 	rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
 			SER_RS485_RTS_AFTER_SEND;

 	/* Only the first port supports delays */
 	if (pdata->index) {
 		rs485->delay_rts_before_send = 0;
 		rs485->delay_rts_after_send = 0;
 	}

 	if (rs485->delay_rts_before_send) {
 		rs485->delay_rts_before_send = 1;
 		config |= TXW4C_IRA;
 	}

 	if (rs485->delay_rts_after_send) {
 		rs485->delay_rts_after_send = 1;
 		config |= RXW4C_IRA;
 	}

 	if (rs485->flags & SER_RS485_RTS_ON_SEND)
 		config |= RTS_INVERT;

 	if (fintek_8250_enter_key(pdata->base_port, pdata->key))
 		return -EBUSY;

 	sio_write_reg(pdata, LDN, pdata->index);
 	sio_write_reg(pdata, RS485, config);
 	fintek_8250_exit_key(pdata->base_port);

 	port->rs485 = *rs485;

 	return 0;
 }

 static void fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool is_level)
 {
 	sio_write_reg(pdata, LDN, pdata->index);

 	switch (pdata->pid) {
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81866:
 		sio_write_mask_reg(pdata, F81866_FIFO_CTRL, F81866_IRQ_MODE1,
 				   0);
 		fallthrough;
 	case CHIP_ID_F81865:
 		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_SHARE,
 				   F81866_IRQ_SHARE);
 		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_MODE0,
 				   is_level ? 0 : F81866_IRQ_MODE0);
 		break;

 	case CHIP_ID_F81216AD:
 	case CHIP_ID_F81216H:
 	case CHIP_ID_F81216:
 		sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_SHARE,
 				   IRQ_SHARE);
 		sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_MODE_MASK,
 				   is_level ? IRQ_LEVEL_LOW : IRQ_EDGE_HIGH);
 		break;
 	}
 }

 static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
 {
 	switch (pdata->pid) {
 	case CHIP_ID_F81216H: /* 128Bytes FIFO */
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81866:
 		sio_write_mask_reg(pdata, FIFO_CTRL,
 				   FIFO_MODE_MASK | RXFTHR_MODE_MASK,
 				   FIFO_MODE_128 | RXFTHR_MODE_4X);
 		break;

 	default: /* Default 16Bytes FIFO */
 		break;
 	}
 }

 static void fintek_8250_goto_highspeed(struct uart_8250_port *uart,
 			      struct fintek_8250 *pdata)
 {
 	sio_write_reg(pdata, LDN, pdata->index);

 	switch (pdata->pid) {
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81866: /* set uart clock for high speed serial mode */
 		sio_write_mask_reg(pdata, F81866_UART_CLK,
 			F81866_UART_CLK_MASK,
 			F81866_UART_CLK_14_769MHZ);

 		uart->port.uartclk = 921600 * 16;
 		break;
 	default: /* leave clock speed untouched */
 		break;
 	}
 }

 static void fintek_8250_set_termios(struct uart_port *port,
 				    struct ktermios *termios,
 				    struct ktermios *old)
 {
 	struct fintek_8250 *pdata = port->private_data;
 	unsigned int baud = tty_termios_baud_rate(termios);
 	int i;
 	u8 reg;
 	static u32 baudrate_table[] = {115200, 921600, 1152000, 1500000};
 	static u8 clock_table[] = { F81866_UART_CLK_1_8432MHZ,
 			F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,
 			F81866_UART_CLK_24MHZ };

 	/*
 	 * We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll
 	 * crash on baudrate_table[i] % baud with "division by zero".
 	 */
 	if (!baud)
 		goto exit;

 	switch (pdata->pid) {
 	case CHIP_ID_F81216H:
 		reg = RS485;
 		break;
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81866:
 		reg = F81866_UART_CLK;
 		break;
 	default:
 		/* Don't change clocksource with unknown PID */
 		dev_warn(port->dev,
 			"%s: pid: %x Not support. use default set_termios.\n",
 			__func__, pdata->pid);
 		goto exit;
 	}

 	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
 		if (baud > baudrate_table[i] || baudrate_table[i] % baud != 0)
 			continue;

 		if (port->uartclk == baudrate_table[i] * 16)
 			break;

 		if (fintek_8250_enter_key(pdata->base_port, pdata->key))
 			continue;

 		port->uartclk = baudrate_table[i] * 16;

 		sio_write_reg(pdata, LDN, pdata->index);
 		sio_write_mask_reg(pdata, reg, F81866_UART_CLK_MASK,
 				clock_table[i]);

 		fintek_8250_exit_key(pdata->base_port);
 		break;
 	}

 	if (i == ARRAY_SIZE(baudrate_table)) {
 		baud = tty_termios_baud_rate(old);
 		tty_termios_encode_baud_rate(termios, baud, baud);
 	}

 exit:
 	serial8250_do_set_termios(port, termios, old);
 }

 static void fintek_8250_set_termios_handler(struct uart_8250_port *uart)
 {
 	struct fintek_8250 *pdata = uart->port.private_data;

 	switch (pdata->pid) {
 	case CHIP_ID_F81216H:
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81866:
 		uart->port.set_termios = fintek_8250_set_termios;
 		break;

 	default:
 		break;
 	}
 }

 static int probe_setup_port(struct fintek_8250 *pdata,
 					struct uart_8250_port *uart)
 {
 	static const u16 addr[] = {0x4e, 0x2e};
 	static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
 	struct irq_data *irq_data;
 	bool level_mode = false;
 	int i, j, k, min, max;

 	for (i = 0; i < ARRAY_SIZE(addr); i++) {
 		for (j = 0; j < ARRAY_SIZE(keys); j++) {
 			pdata->base_port = addr[i];
 			pdata->key = keys[j];

 			if (fintek_8250_enter_key(addr[i], keys[j]))
 				continue;
 			if (fintek_8250_check_id(pdata) ||
 			    fintek_8250_get_ldn_range(pdata, &min, &max)) {
 				fintek_8250_exit_key(addr[i]);
 				continue;
 			}

 			for (k = min; k < max; k++) {
 				u16 aux;

 				sio_write_reg(pdata, LDN, k);
 				aux = sio_read_reg(pdata, IO_ADDR1);
 				aux |= sio_read_reg(pdata, IO_ADDR2) << 8;
 				if (aux != uart->port.iobase)
 					continue;

 				pdata->index = k;

 				irq_data = irq_get_irq_data(uart->port.irq);
 				if (irq_data)
 					level_mode =
 						irqd_is_level_type(irq_data);

 				fintek_8250_set_irq_mode(pdata, level_mode);
 				fintek_8250_set_max_fifo(pdata);
 				fintek_8250_goto_highspeed(uart, pdata);

 				fintek_8250_exit_key(addr[i]);

 				return 0;
 			}

 			fintek_8250_exit_key(addr[i]);
 		}
 	}

 	return -ENODEV;
 }

 static void fintek_8250_set_rs485_handler(struct uart_8250_port *uart)
 {
 	struct fintek_8250 *pdata = uart->port.private_data;

 	switch (pdata->pid) {
 	case CHIP_ID_F81216AD:
 	case CHIP_ID_F81216H:
 	case CHIP_ID_F81966:
 	case CHIP_ID_F81866:
 	case CHIP_ID_F81865:
 		uart->port.rs485_config = fintek_8250_rs485_config;
 		break;

 	default: /* No RS485 Auto direction functional */
 		break;
 	}
 }

 int fintek_8250_probe(struct uart_8250_port *uart)
 {
 	struct fintek_8250 *pdata;
 	struct fintek_8250 probe_data;

 	if (probe_setup_port(&probe_data, uart))
 		return -ENODEV;

 	pdata = devm_kzalloc(uart->port.dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;

 	memcpy(pdata, &probe_data, sizeof(probe_data));
 	uart->port.private_data = pdata;
 	fintek_8250_set_rs485_handler(uart);
 	fintek_8250_set_termios_handler(uart);

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Probe for F81216A LPC to 4 UART
	*
	* Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S
	*/
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/pnp.h>
	#include <linux/kernel.h>
	#include <linux/serial_core.h>
	#include <linux/irq.h>
	#include "8250.h"

	#define ADDR_PORT 0
	#define DATA_PORT 1
	#define EXIT_KEY 0xAA
	#define CHIP_ID1 0x20
	#define CHIP_ID2 0x21
	#define CHIP_ID_F81865 0x0407
	#define CHIP_ID_F81866 0x1010
	#define CHIP_ID_F81966 0x0215
	#define CHIP_ID_F81216AD 0x1602
	#define CHIP_ID_F81216H 0x0501
	#define CHIP_ID_F81216 0x0802
	#define VENDOR_ID1 0x23
	#define VENDOR_ID1_VAL 0x19
	#define VENDOR_ID2 0x24
	#define VENDOR_ID2_VAL 0x34
	#define IO_ADDR1 0x61
	#define IO_ADDR2 0x60
	#define LDN 0x7

	#define FINTEK_IRQ_MODE 0x70
	#define IRQ_SHARE BIT(4)
	#define IRQ_MODE_MASK (BIT(6) \| BIT(5))
	#define IRQ_LEVEL_LOW 0
	#define IRQ_EDGE_HIGH BIT(5)

	/*
	* F81216H clock source register, the value and mask is the same with F81866,
	* but it's on F0h.
	*
	* Clock speeds for UART (register F0h)
	* 00: 1.8432MHz.
	* 01: 18.432MHz.
	* 10: 24MHz.
	* 11: 14.769MHz.
	*/
	#define RS485 0xF0
	#define RTS_INVERT BIT(5)
	#define RS485_URA BIT(4)
	#define RXW4C_IRA BIT(3)
	#define TXW4C_IRA BIT(2)

	#define FIFO_CTRL 0xF6
	#define FIFO_MODE_MASK (BIT(1) \| BIT(0))
	#define FIFO_MODE_128 (BIT(1) \| BIT(0))
	#define RXFTHR_MODE_MASK (BIT(5) \| BIT(4))
	#define RXFTHR_MODE_4X BIT(5)

	#define F81216_LDN_LOW 0x0
	#define F81216_LDN_HIGH 0x4

	/*
	* F81866/966 registers
	*
	* The IRQ setting mode of F81866/966 is not the same with F81216 series.
	* Level/Low: IRQ_MODE0:0, IRQ_MODE1:0
	* Edge/High: IRQ_MODE0:1, IRQ_MODE1:0
	*
	* Clock speeds for UART (register F2h)
	* 00: 1.8432MHz.
	* 01: 18.432MHz.
	* 10: 24MHz.
	* 11: 14.769MHz.
	*/
	#define F81866_IRQ_MODE 0xf0
	#define F81866_IRQ_SHARE BIT(0)
	#define F81866_IRQ_MODE0 BIT(1)

	#define F81866_FIFO_CTRL FIFO_CTRL
	#define F81866_IRQ_MODE1 BIT(3)

	#define F81866_LDN_LOW 0x10
	#define F81866_LDN_HIGH 0x16

	#define F81866_UART_CLK 0xF2
	#define F81866_UART_CLK_MASK (BIT(1) \| BIT(0))
	#define F81866_UART_CLK_1_8432MHZ 0
	#define F81866_UART_CLK_14_769MHZ (BIT(1) \| BIT(0))
	#define F81866_UART_CLK_18_432MHZ BIT(0)
	#define F81866_UART_CLK_24MHZ BIT(1)

	struct fintek_8250 {
	u16 pid;
	u16 base_port;
	u8 index;
	u8 key;
	};

	static u8 sio_read_reg(struct fintek_8250 *pdata, u8 reg)
	{
	outb(reg, pdata->base_port + ADDR_PORT);
	return inb(pdata->base_port + DATA_PORT);
	}

	static void sio_write_reg(struct fintek_8250 *pdata, u8 reg, u8 data)
	{
	outb(reg, pdata->base_port + ADDR_PORT);
	outb(data, pdata->base_port + DATA_PORT);
	}

	static void sio_write_mask_reg(struct fintek_8250 *pdata, u8 reg, u8 mask,
	u8 data)
	{
	u8 tmp;

	tmp = (sio_read_reg(pdata, reg) & ~mask) \| (mask & data);
	sio_write_reg(pdata, reg, tmp);
	}

	static int fintek_8250_enter_key(u16 base_port, u8 key)
	{
	if (!request_muxed_region(base_port, 2, "8250_fintek"))
	return -EBUSY;

	/* Force to deactive all SuperIO in this base_port */
	outb(EXIT_KEY, base_port + ADDR_PORT);

	outb(key, base_port + ADDR_PORT);
	outb(key, base_port + ADDR_PORT);
	return 0;
	}

	static void fintek_8250_exit_key(u16 base_port)
	{

	outb(EXIT_KEY, base_port + ADDR_PORT);
	release_region(base_port + ADDR_PORT, 2);
	}

	static int fintek_8250_check_id(struct fintek_8250 *pdata)
	{
	u16 chip;

	if (sio_read_reg(pdata, VENDOR_ID1) != VENDOR_ID1_VAL)
	return -ENODEV;

	if (sio_read_reg(pdata, VENDOR_ID2) != VENDOR_ID2_VAL)
	return -ENODEV;

	chip = sio_read_reg(pdata, CHIP_ID1);
	chip \|= sio_read_reg(pdata, CHIP_ID2) << 8;

	switch (chip) {
	case CHIP_ID_F81865:
	case CHIP_ID_F81866:
	case CHIP_ID_F81966:
	case CHIP_ID_F81216AD:
	case CHIP_ID_F81216H:
	case CHIP_ID_F81216:
	break;
	default:
	return -ENODEV;
	}

	pdata->pid = chip;
	return 0;
	}

	static int fintek_8250_get_ldn_range(struct fintek_8250 pdata, int min,
	int *max)
	{
	switch (pdata->pid) {
	case CHIP_ID_F81966:
	case CHIP_ID_F81865:
	case CHIP_ID_F81866:
	*min = F81866_LDN_LOW;
	*max = F81866_LDN_HIGH;
	return 0;

	case CHIP_ID_F81216AD:
	case CHIP_ID_F81216H:
	case CHIP_ID_F81216:
	*min = F81216_LDN_LOW;
	*max = F81216_LDN_HIGH;
	return 0;
	}

	return -ENODEV;
	}

	static int fintek_8250_rs485_config(struct uart_port *port,
	struct serial_rs485 *rs485)
	{
	uint8_t config = 0;
	struct fintek_8250 *pdata = port->private_data;

	if (!pdata)
	return -EINVAL;

	/* Hardware do not support same RTS level on send and receive */
	if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
	!(rs485->flags & SER_RS485_RTS_AFTER_SEND))
	return -EINVAL;

	if (rs485->flags & SER_RS485_ENABLED) {
	memset(rs485->padding, 0, sizeof(rs485->padding));
	config \|= RS485_URA;
	} else {
	memset(rs485, 0, sizeof(*rs485));
	}

	rs485->flags &= SER_RS485_ENABLED \| SER_RS485_RTS_ON_SEND \|
	SER_RS485_RTS_AFTER_SEND;

	/* Only the first port supports delays */
	if (pdata->index) {
	rs485->delay_rts_before_send = 0;
	rs485->delay_rts_after_send = 0;
	}

	if (rs485->delay_rts_before_send) {
	rs485->delay_rts_before_send = 1;
	config \|= TXW4C_IRA;
	}

	if (rs485->delay_rts_after_send) {
	rs485->delay_rts_after_send = 1;
	config \|= RXW4C_IRA;
	}

	if (rs485->flags & SER_RS485_RTS_ON_SEND)
	config \|= RTS_INVERT;

	if (fintek_8250_enter_key(pdata->base_port, pdata->key))
	return -EBUSY;

	sio_write_reg(pdata, LDN, pdata->index);
	sio_write_reg(pdata, RS485, config);
	fintek_8250_exit_key(pdata->base_port);

	port->rs485 = *rs485;

	return 0;
	}

	static void fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool is_level)
	{
	sio_write_reg(pdata, LDN, pdata->index);

	switch (pdata->pid) {
	case CHIP_ID_F81966:
	case CHIP_ID_F81866:
	sio_write_mask_reg(pdata, F81866_FIFO_CTRL, F81866_IRQ_MODE1,
	0);
	fallthrough;
	case CHIP_ID_F81865:
	sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_SHARE,
	F81866_IRQ_SHARE);
	sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_MODE0,
	is_level ? 0 : F81866_IRQ_MODE0);
	break;

	case CHIP_ID_F81216AD:
	case CHIP_ID_F81216H:
	case CHIP_ID_F81216:
	sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_SHARE,
	IRQ_SHARE);
	sio_write_mask_reg(pdata, FINTEK_IRQ_MODE, IRQ_MODE_MASK,
	is_level ? IRQ_LEVEL_LOW : IRQ_EDGE_HIGH);
	break;
	}
	}

	static void fintek_8250_set_max_fifo(struct fintek_8250 *pdata)
	{
	switch (pdata->pid) {
	case CHIP_ID_F81216H: /* 128Bytes FIFO */
	case CHIP_ID_F81966:
	case CHIP_ID_F81866:
	sio_write_mask_reg(pdata, FIFO_CTRL,
	FIFO_MODE_MASK \| RXFTHR_MODE_MASK,
	FIFO_MODE_128 \| RXFTHR_MODE_4X);
	break;

	default: /* Default 16Bytes FIFO */
	break;
	}
	}

	static void fintek_8250_goto_highspeed(struct uart_8250_port *uart,
	struct fintek_8250 *pdata)
	{
	sio_write_reg(pdata, LDN, pdata->index);

	switch (pdata->pid) {
	case CHIP_ID_F81966:
	case CHIP_ID_F81866: /* set uart clock for high speed serial mode */
	sio_write_mask_reg(pdata, F81866_UART_CLK,
	F81866_UART_CLK_MASK,
	F81866_UART_CLK_14_769MHZ);

	uart->port.uartclk = 921600 * 16;
	break;
	default: /* leave clock speed untouched */
	break;
	}
	}

	static void fintek_8250_set_termios(struct uart_port *port,
	struct ktermios *termios,
	struct ktermios *old)
	{
	struct fintek_8250 *pdata = port->private_data;
	unsigned int baud = tty_termios_baud_rate(termios);
	int i;
	u8 reg;
	static u32 baudrate_table[] = {115200, 921600, 1152000, 1500000};
	static u8 clock_table[] = { F81866_UART_CLK_1_8432MHZ,
	F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,
	F81866_UART_CLK_24MHZ };

	/*
	* We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll
	* crash on baudrate_table[i] % baud with "division by zero".
	*/
	if (!baud)
	goto exit;

	switch (pdata->pid) {
	case CHIP_ID_F81216H:
	reg = RS485;
	break;
	case CHIP_ID_F81966:
	case CHIP_ID_F81866:
	reg = F81866_UART_CLK;
	break;
	default:
	/* Don't change clocksource with unknown PID */
	dev_warn(port->dev,
	"%s: pid: %x Not support. use default set_termios.\n",
	__func__, pdata->pid);
	goto exit;
	}

	for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
	if (baud > baudrate_table[i] \|\| baudrate_table[i] % baud != 0)
	continue;

	if (port->uartclk == baudrate_table[i] * 16)
	break;

	if (fintek_8250_enter_key(pdata->base_port, pdata->key))
	continue;

	port->uartclk = baudrate_table[i] * 16;

	sio_write_reg(pdata, LDN, pdata->index);
	sio_write_mask_reg(pdata, reg, F81866_UART_CLK_MASK,
	clock_table[i]);

	fintek_8250_exit_key(pdata->base_port);
	break;
	}

	if (i == ARRAY_SIZE(baudrate_table)) {
	baud = tty_termios_baud_rate(old);
	tty_termios_encode_baud_rate(termios, baud, baud);
	}

	exit:
	serial8250_do_set_termios(port, termios, old);
	}

	static void fintek_8250_set_termios_handler(struct uart_8250_port *uart)
	{
	struct fintek_8250 *pdata = uart->port.private_data;

	switch (pdata->pid) {
	case CHIP_ID_F81216H:
	case CHIP_ID_F81966:
	case CHIP_ID_F81866:
	uart->port.set_termios = fintek_8250_set_termios;
	break;

	default:
	break;
	}
	}

	static int probe_setup_port(struct fintek_8250 *pdata,
	struct uart_8250_port *uart)
	{
	static const u16 addr[] = {0x4e, 0x2e};
	static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
	struct irq_data *irq_data;
	bool level_mode = false;
	int i, j, k, min, max;

	for (i = 0; i < ARRAY_SIZE(addr); i++) {
	for (j = 0; j < ARRAY_SIZE(keys); j++) {
	pdata->base_port = addr[i];
	pdata->key = keys[j];

	if (fintek_8250_enter_key(addr[i], keys[j]))
	continue;
	if (fintek_8250_check_id(pdata) \|\|
	fintek_8250_get_ldn_range(pdata, &min, &max)) {
	fintek_8250_exit_key(addr[i]);
	continue;
	}

	for (k = min; k < max; k++) {
	u16 aux;

	sio_write_reg(pdata, LDN, k);
	aux = sio_read_reg(pdata, IO_ADDR1);
	aux \|= sio_read_reg(pdata, IO_ADDR2) << 8;
	if (aux != uart->port.iobase)
	continue;

	pdata->index = k;

	irq_data = irq_get_irq_data(uart->port.irq);
	if (irq_data)
	level_mode =
	irqd_is_level_type(irq_data);

	fintek_8250_set_irq_mode(pdata, level_mode);
	fintek_8250_set_max_fifo(pdata);
	fintek_8250_goto_highspeed(uart, pdata);

	fintek_8250_exit_key(addr[i]);

	return 0;
	}

	fintek_8250_exit_key(addr[i]);
	}
	}

	return -ENODEV;
	}

	static void fintek_8250_set_rs485_handler(struct uart_8250_port *uart)
	{
	struct fintek_8250 *pdata = uart->port.private_data;

	switch (pdata->pid) {
	case CHIP_ID_F81216AD:
	case CHIP_ID_F81216H:
	case CHIP_ID_F81966:
	case CHIP_ID_F81866:
	case CHIP_ID_F81865:
	uart->port.rs485_config = fintek_8250_rs485_config;
	break;

	default: /* No RS485 Auto direction functional */
	break;
	}
	}

	int fintek_8250_probe(struct uart_8250_port *uart)
	{
	struct fintek_8250 *pdata;
	struct fintek_8250 probe_data;

	if (probe_setup_port(&probe_data, uart))
	return -ENODEV;

	pdata = devm_kzalloc(uart->port.dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return -ENOMEM;

	memcpy(pdata, &probe_data, sizeof(probe_data));
	uart->port.private_data = pdata;
	fintek_8250_set_rs485_handler(uart);
	fintek_8250_set_termios_handler(uart);

	return 0;
	}