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Commit fa01e2ca authored by Ricardo Ribalda Delgado's avatar Ricardo Ribalda Delgado Committed by Greg Kroah-Hartman
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serial: 8250: Integrate Fintek into 8250_base 



The 8250_fintek driver advertises as the PNP0501 driver; however this
conflicts with the standard 16550A uart PNP0501. The conflict causes
the 8250_fintek driver to load with _every_ PNP0501, but never probe,
and causing the entire 8250 driver stack to unload if the 8250_fintek
driver is unloaded (modprobe doesn't know that 8250_pnp rather than
8250_fintek claimed the resource).

This patch merges the Fintek driver into 8250_base. On autoconfig_16550
the device is probed to verify if it is a FINTEK device or not.

This custom probing can be disabled completely via configuration. When a
Fintek device is not probed it will behave as a standard 16550A device,
with no RS485 capabilities.

Reported-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Reviewed-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent bd8d257f

drivers/tty/serial/8250/8250.h

+6 −0
Original line number Diff line number Diff line
@@ -150,6 +150,12 @@ static inline int serial8250_pnp_init(void) { return 0; } 
static inline void serial8250_pnp_exit(void) { }

#endif



#ifdef CONFIG_SERIAL_8250_FINTEK

int fintek_8250_probe(struct uart_8250_port *uart);

#else

static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }

#endif



#ifdef CONFIG_ARCH_OMAP1

static inline int is_omap1_8250(struct uart_8250_port *pt)

{

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

+16 −102
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

 *  Copyright (C) 2014-2016 Ricardo Ribalda, Qtechnology A/S

 *

 *

 * This program is free software; you can redistribute it and/or modify
@@ -38,19 +36,15 @@ 
#define RXW4C_IRA BIT(3)

#define TXW4C_IRA BIT(2)



#define DRIVER_NAME "8250_fintek"



struct fintek_8250 {

	u16 base_port;

	u8 index;

	u8 key;

	long line;

};



static int fintek_8250_enter_key(u16 base_port, u8 key)

{



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

	if (!request_muxed_region(base_port, 2, "8250_fintek"))

		return -EBUSY;



	outb(key, base_port + ADDR_PORT);
@@ -138,7 +132,7 @@ static int fintek_8250_rs485_config(struct uart_port *port, 
	return 0;

}



static int fintek_8250_base_port(u16 io_address, u8 *key, u8 *index)

static int find_base_port(struct fintek_8250 *pdata, u16 io_address)

{

	static const u16 addr[] = {0x4e, 0x2e};

	static const u8 keys[] = {0x77, 0xa0, 0x87, 0x67};
@@ -168,10 +162,13 @@ static int fintek_8250_base_port(u16 io_address, u8 *key, u8 *index) 
					continue;



				fintek_8250_exit_key(addr[i]);

				*key = keys[j];

				*index = k;

				return addr[i];

				pdata->key = keys[j];

				pdata->base_port = addr[i];

				pdata->index = k;



				return 0;

			}



			fintek_8250_exit_key(addr[i]);

		}

	}
@@ -179,104 +176,21 @@ static int fintek_8250_base_port(u16 io_address, u8 *key, u8 *index) 
	return -ENODEV;

}



static int

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

int fintek_8250_probe(struct uart_8250_port *uart)

{

	struct uart_8250_port uart;

	struct fintek_8250 *pdata;

	int base_port;

	u8 key;

	u8 index;



	if (!pnp_port_valid(dev, 0))

		return -ENODEV;

	struct fintek_8250 probe_data;



	base_port = fintek_8250_base_port(pnp_port_start(dev, 0), &key, &index);

	if (base_port < 0)

	if (find_base_port(&probe_data, uart->port.iobase))

		return -ENODEV;



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



	pdata = devm_kzalloc(&dev->dev, sizeof(*pdata), GFP_KERNEL);

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

	if (!pdata)

		return -ENOMEM;

	uart.port.private_data = pdata;



	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.port.rs485_config = fintek_8250_rs485_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;



	pdata->key = key;

	pdata->base_port = base_port;

	pdata->index = index;

	pdata->line = serial8250_register_8250_port(&uart);

	if (pdata->line < 0)

		return -ENODEV;



	pnp_set_drvdata(dev, pdata);

	return 0;

}



static void fintek_8250_remove(struct pnp_dev *dev)

{

	struct fintek_8250 *pdata = pnp_get_drvdata(dev);



	if (pdata)

		serial8250_unregister_port(pdata->line);

}



#ifdef CONFIG_PM

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

{

	struct fintek_8250 *pdata = pnp_get_drvdata(dev);



	if (!pdata)

		return -ENODEV;

	serial8250_suspend_port(pdata->line);

	return 0;

}



static int fintek_8250_resume(struct pnp_dev *dev)

{

	struct fintek_8250 *pdata = pnp_get_drvdata(dev);

	memcpy(pdata, &probe_data, sizeof(probe_data));

	uart->port.rs485_config = fintek_8250_rs485_config;

	uart->port.private_data = pdata;



	if (!pdata)

		return -ENODEV;

	serial8250_resume_port(pdata->line);

	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,

};



module_pnp_driver(fintek_8250_driver);

MODULE_DESCRIPTION("Fintek F812164 module");

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

MODULE_LICENSE("GPL");

drivers/tty/serial/8250/8250_port.c

+7 −0
Original line number Diff line number Diff line
@@ -1315,6 +1315,13 @@ static void autoconfig(struct uart_8250_port *up) 


out_lock:

	spin_unlock_irqrestore(&port->lock, flags);



	/*

	 * Check if the device is a Fintek F81216A

	 */

	if (port->type == PORT_16550A)

		fintek_8250_probe(up);



	if (up->capabilities != old_capabilities) {

		pr_warn("ttyS%d: detected caps %08x should be %08x\n",

		       serial_index(port), old_capabilities,

drivers/tty/serial/8250/Kconfig

+12 −8
Original line number Diff line number Diff line
@@ -57,6 +57,18 @@ config SERIAL_8250_PNP 
	  This builds standard PNP serial support. You may be able to

	  disable this feature if you only need legacy serial support.



config SERIAL_8250_FINTEK

	bool "Support for Fintek F81216A LPC to 4 UART RS485 API"

	depends on SERIAL_8250

	---help---

	  Selecting this option will add support for the RS485 capabilities

	  of the Fintek F81216A LPC to 4 UART.



	  If this option is not selected the device will be configured as a

	  standard 16550A serial port.



	  If unsure, say N.



config SERIAL_8250_CONSOLE

	bool "Console on 8250/16550 and compatible serial port"

	depends on SERIAL_8250=y
@@ -358,14 +370,6 @@ config SERIAL_8250_OMAP_TTYO_FIXUP 
	  not booting kernel because the serial console remains silent in case

	  they forgot to update the command line.



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.



config SERIAL_8250_LPC18XX

	tristate "NXP LPC18xx/43xx serial port support"

	depends on SERIAL_8250 && OF && (ARCH_LPC18XX || COMPILE_TEST)

drivers/tty/serial/8250/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250.o 8250_base.o 
8250-$(CONFIG_SERIAL_8250_PNP)		+= 8250_pnp.o

8250_base-y				:= 8250_port.o

8250_base-$(CONFIG_SERIAL_8250_DMA)	+= 8250_dma.o

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

obj-$(CONFIG_SERIAL_8250_GSC)		+= 8250_gsc.o

obj-$(CONFIG_SERIAL_8250_PCI)		+= 8250_pci.o

obj-$(CONFIG_SERIAL_8250_HP300)		+= 8250_hp300.o
@@ -23,7 +24,6 @@ obj-$(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_OMAP)		+= 8250_omap.o

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

obj-$(CONFIG_SERIAL_8250_LPC18XX)	+= 8250_lpc18xx.o

obj-$(CONFIG_SERIAL_8250_MT6577)	+= 8250_mtk.o

obj-$(CONFIG_SERIAL_8250_UNIPHIER)	+= 8250_uniphier.o