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Commit 28e3fb6c authored by Ricardo Ribalda Delgado's avatar Ricardo Ribalda Delgado Committed by Greg Kroah-Hartman
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serial: Add support for Fintek F81216A LPC to 4 UART 



This patch lets you set the RS485 cappabilites of the device through
TIOCSRS485 and TIOCGRS485 as defined on Documentation/serial/serial-rs485.txt

In order to probe the device, the PNP id and the device id is used.

Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e676253b

drivers/tty/serial/8250/8250_fintek.c

0 → 100644
+249 −0
Original line number Diff line number Diff line 
/*

 *  Probe for F81216A LPC to 4 UART

 *

 *  Based on drivers/tty/serial/8250_pnp.c, by Russell King, et al

 *

 *  Copyright (C) 2014 Ricardo Ribalda, Qtechnology A/S

 *

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License.

 */

#include <linux/module.h>

#include <linux/pci.h>

#include <linux/pnp.h>

#include <linux/kernel.h>

#include <linux/serial_core.h>

#include  "8250.h"



#define ADDR_PORT 0x4E

#define DATA_PORT 0x4F

#define ENTRY_KEY 0x77

#define EXIT_KEY 0xAA

#define CHIP_ID1  0x20

#define CHIP_ID1_VAL 0x02

#define CHIP_ID2  0x21

#define CHIP_ID2_VAL 0x16

#define VENDOR_ID1 0x23

#define VENDOR_ID1_VAL 0x19

#define VENDOR_ID2 0x24

#define VENDOR_ID2_VAL 0x34

#define LDN 0x7



#define RS485  0xF0

#define RTS_INVERT BIT(5)

#define RS485_URA BIT(4)

#define RXW4C_IRA BIT(3)

#define TXW4C_IRA BIT(2)



#define DRIVER_NAME "8250_fintek"



static int fintek_8250_enter_key(void){



	if (!request_muxed_region(ADDR_PORT, 2, DRIVER_NAME))

		return -EBUSY;



	outb(ENTRY_KEY, ADDR_PORT);

	outb(ENTRY_KEY, ADDR_PORT);

	return 0;

}



static void fintek_8250_exit_key(void){



	outb(EXIT_KEY, ADDR_PORT);

	release_region(ADDR_PORT, 2);

}



static int fintek_8250_get_index(resource_size_t base_addr)

{

	resource_size_t base[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8};

	int i;



	for (i = 0; i < ARRAY_SIZE(base); i++)

		if (base_addr == base[i])

			return i;



	return -ENODEV;

}



static int fintek_8250_check_id(void)

{



	outb(CHIP_ID1, ADDR_PORT);

	if (inb(DATA_PORT) != CHIP_ID1_VAL)

		return -ENODEV;



	outb(CHIP_ID2, ADDR_PORT);

	if (inb(DATA_PORT) != CHIP_ID2_VAL)

		return -ENODEV;



	outb(VENDOR_ID1, ADDR_PORT);

	if (inb(DATA_PORT) != VENDOR_ID1_VAL)

		return -ENODEV;



	outb(VENDOR_ID2, ADDR_PORT);

	if (inb(DATA_PORT) != VENDOR_ID2_VAL)

		return -ENODEV;



	return 0;

}



static int fintek_8250_rs4850_config(struct uart_8250_port *uart,

			      struct serial_rs485 *rs485)

{

	uint8_t config = 0;

	int index = fintek_8250_get_index(uart->port.iobase);



	if (index < 0)

		return -EINVAL;



	if (rs485->flags & SER_RS485_ENABLED)

		memset(rs485->padding, 0, sizeof(rs485->padding));

	else

		memset(rs485, 0, sizeof(*rs485));



	rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |

			SER_RS485_RTS_AFTER_SEND;



	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)) ==

			(!!(rs485->flags & SER_RS485_RTS_AFTER_SEND)))

		rs485->flags &= SER_RS485_ENABLED;

	else

		config |= RS485_URA;



	if (rs485->flags & SER_RS485_RTS_ON_SEND)

		config |= RTS_INVERT;



	if (fintek_8250_enter_key())

		return -EBUSY;



	outb(LDN, ADDR_PORT);

	outb(index, DATA_PORT);

	outb(RS485, ADDR_PORT);

	outb(config, DATA_PORT);

	fintek_8250_exit_key();



	return 0;

}



static int

fintek_8250_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)

{

	int line;

	struct uart_8250_port uart;

	int ret;



	if (!pnp_port_valid(dev, 0))

		return -ENODEV;



	if (fintek_8250_get_index(pnp_port_start(dev, 0)) < 0)

		return -ENODEV;



	/* Enable configuration registers*/

	if (fintek_8250_enter_key())

		return -EBUSY;



	/*Check ID*/

	ret = fintek_8250_check_id();

	fintek_8250_exit_key();

	if (ret)

		return ret;



	memset(&uart, 0, sizeof(uart));

	if (!pnp_irq_valid(dev, 0))

		return -ENODEV;

	uart.port.irq = pnp_irq(dev, 0);

	uart.port.iobase = pnp_port_start(dev, 0);

	uart.port.iotype = UPIO_PORT;

	uart.rs485_config = fintek_8250_rs4850_config;



	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;

	if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)

		uart.port.flags |= UPF_SHARE_IRQ;

	uart.port.uartclk = 1843200;

	uart.port.dev = &dev->dev;



	line = serial8250_register_8250_port(&uart);

	if (line < 0)

		return -ENODEV;



	pnp_set_drvdata(dev, (void *)((long)line + 1));

	return 0;

}



static void fintek_8250_remove(struct pnp_dev *dev)

{

	long line = (long)pnp_get_drvdata(dev);



	if (line)

		serial8250_unregister_port(line - 1);

}



#ifdef CONFIG_PM

static int fintek_8250_suspend(struct pnp_dev *dev, pm_message_t state)

{

	long line = (long)pnp_get_drvdata(dev);



	if (!line)

		return -ENODEV;

	serial8250_suspend_port(line - 1);

	return 0;

}



static int fintek_8250_resume(struct pnp_dev *dev)

{

	long line = (long)pnp_get_drvdata(dev);



	if (!line)

		return -ENODEV;

	serial8250_resume_port(line - 1);

	return 0;

}

#else

#define fintek_8250_suspend NULL

#define fintek_8250_resume NULL

#endif /* CONFIG_PM */



static const struct pnp_device_id fintek_dev_table[] = {

	/* Qtechnology Panel PC / IO1000 */

	{ "PNP0501"},

	{}

};



MODULE_DEVICE_TABLE(pnp, fintek_dev_table);



static struct pnp_driver fintek_8250_driver = {

	.name		= DRIVER_NAME,

	.probe		= fintek_8250_probe,

	.remove		= fintek_8250_remove,

	.suspend	= fintek_8250_suspend,

	.resume		= fintek_8250_resume,

	.id_table	= fintek_dev_table,

};



static int fintek_8250_init(void)

{

	return pnp_register_driver(&fintek_8250_driver);

}

module_init(fintek_8250_init);



static void fintek_8250_exit(void)

{

	pnp_unregister_driver(&fintek_8250_driver);

}

module_exit(fintek_8250_exit);



MODULE_DESCRIPTION("Fintek F812164 module");

MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>");

MODULE_LICENSE("GPL");

drivers/tty/serial/8250/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -298,3 +298,12 @@ config SERIAL_8250_RT288X 
	  If you have a Ralink RT288x/RT305x SoC based board and want to use the

	  serial port, say Y to this option. The driver can handle up to 2 serial

	  ports. If unsure, say N.



config SERIAL_8250_FINTEK

	tristate "Support for Fintek F81216A LPC to 4 UART"

	depends on SERIAL_8250 && PNP

	help

	  Selecting this option will add support for the Fintek F81216A

	  LPC to 4 UART. This device has some RS485 functionality not available

	  through the PNP driver. If unsure, say N.

drivers/tty/serial/8250/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -20,3 +20,4 @@ obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o 
obj-$(CONFIG_SERIAL_8250_FSL)		+= 8250_fsl.o

obj-$(CONFIG_SERIAL_8250_DW)		+= 8250_dw.o

obj-$(CONFIG_SERIAL_8250_EM)		+= 8250_em.o

obj-$(CONFIG_SERIAL_8250_FINTEK)	+= 8250_fintek.o