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Commit ab28f51c authored by Sergey Yanovich's avatar Sergey Yanovich Committed by Greg Kroah-Hartman
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serial: rewrite pxa2xx-uart to use 8250_core 



pxa2xx-uart was a separate uart platform driver. It was declaring
the same device names and numbers as 8250 driver. As a result,
it was impossible to use 8250 driver on PXA SoCs.

Upon closer examination pxa2xx-uart turned out to be a clone of
8250_core driver.

Workaround for Erratum #19 according to Marvel(R) PXA270M Processor
Specification Update (April 19, 2010) is dropped. 8250_core reads
from FIFO immediately after checking DR bit in LSR.

The patch leaves the original SERIAL_PXA driver around. The original
driver is just marked DEPRECATED in Kconfig and C source. When
the original driver is considered safe to remove, no changes
to SERIAL_8250 will be necessary.

Compiling SERIAL_8250_CONSOLE and SERIAL_PXA_CONSOLE even without
SERIAL_8250_PXA breaks console for SERIAL_PXA. For this reasons, the new
and the original drivers are made mutually exclusive.

Signed-off-by: default avatarSergei Ianovich <ynvich@gmail.com>
CC: Heikki Krogerus <heikki.krogerus@linux.intel.com>
CC: James Cameron <quozl@laptop.org>
CC: Robert Jarzmik <robert.jarzmik@free.fr>
CC: Russell King <linux@arm.linux.org.uk>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
[rebased on v4.8]
Tested-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 07d9a380

drivers/tty/serial/8250/8250_pxa.c

0 → 100644
+177 −0
Original line number Diff line number Diff line 
/*

 *  drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS

 *  Copyright:	(C) 2013 Sergei Ianovich <ynvich@gmail.com>

 *

 *  replaces drivers/serial/pxa.c by Nicolas Pitre

 *  Created:	Feb 20, 2003

 *  Copyright:	(C) 2003 Monta Vista Software, Inc.

 *

 *  Based on drivers/serial/8250.c by Russell King.

 *

 * 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, or

 * (at your option) any later version.

 *

 */



#include <linux/device.h>

#include <linux/init.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/serial_8250.h>

#include <linux/serial_core.h>

#include <linux/serial_reg.h>

#include <linux/of.h>

#include <linux/of_irq.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/clk.h>

#include <linux/pm_runtime.h>



#include "8250.h"



struct pxa8250_data {

	int			line;

	struct clk		*clk;

};



#ifdef CONFIG_PM

static int serial_pxa_suspend(struct device *dev)

{

	struct pxa8250_data *data = dev_get_drvdata(dev);



	serial8250_suspend_port(data->line);



	return 0;

}



static int serial_pxa_resume(struct device *dev)

{

	struct pxa8250_data *data = dev_get_drvdata(dev);



	serial8250_resume_port(data->line);



	return 0;

}

#endif



static const struct dev_pm_ops serial_pxa_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume)

};



static const struct of_device_id serial_pxa_dt_ids[] = {

	{ .compatible = "mrvl,pxa-uart", },

	{ .compatible = "mrvl,mmp-uart", },

	{}

};

MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);



/* Uart divisor latch write */

static void serial_pxa_dl_write(struct uart_8250_port *up, int value)

{

	unsigned int dll;



	serial_out(up, UART_DLL, value & 0xff);

	/*

	 * work around Erratum #74 according to Marvel(R) PXA270M Processor

	 * Specification Update (April 19, 2010)

	 */

	dll = serial_in(up, UART_DLL);

	WARN_ON(dll != (value & 0xff));



	serial_out(up, UART_DLM, value >> 8 & 0xff);

}





static void serial_pxa_pm(struct uart_port *port, unsigned int state,

	      unsigned int oldstate)

{

	struct pxa8250_data *data = port->private_data;



	if (!state)

		clk_prepare_enable(data->clk);

	else

		clk_disable_unprepare(data->clk);

}



static int serial_pxa_probe(struct platform_device *pdev)

{

	struct uart_8250_port uart = {};

	struct pxa8250_data *data;

	struct resource *mmres, *irqres;

	int ret;



	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

	if (!mmres || !irqres)

		return -ENODEV;



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

	if (!data)

		return -ENOMEM;



	data->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(data->clk))

		return PTR_ERR(data->clk);



	ret = clk_prepare(data->clk);

	if (ret)

		return ret;



	uart.port.type = PORT_XSCALE;

	uart.port.iotype = UPIO_MEM32;

	uart.port.mapbase = mmres->start;

	uart.port.regshift = 2;

	uart.port.irq = irqres->start;

	uart.port.fifosize = 64;

	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST;

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

	uart.port.uartclk = clk_get_rate(data->clk);

	uart.port.pm = serial_pxa_pm;

	uart.port.private_data = data;

	uart.dl_write = serial_pxa_dl_write;



	ret = serial8250_register_8250_port(&uart);

	if (ret < 0)

		goto err_clk;



	data->line = ret;



	platform_set_drvdata(pdev, data);



	return 0;



 err_clk:

	clk_unprepare(data->clk);

	return ret;

}



static int serial_pxa_remove(struct platform_device *pdev)

{

	struct pxa8250_data *data = platform_get_drvdata(pdev);



	serial8250_unregister_port(data->line);



	clk_unprepare(data->clk);



	return 0;

}



static struct platform_driver serial_pxa_driver = {

	.probe          = serial_pxa_probe,

	.remove         = serial_pxa_remove,



	.driver		= {

		.name	= "pxa2xx-uart",

		.pm	= &serial_pxa_pm_ops,

		.of_match_table = serial_pxa_dt_ids,

	},

};



module_platform_driver(serial_pxa_driver);



MODULE_AUTHOR("Sergei Ianovich");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:pxa2xx-uart");

drivers/tty/serial/8250/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -439,6 +439,16 @@ config SERIAL_8250_MOXA 
	  This driver can also be built as a module. The module will be called

	  8250_moxa. If you want to do that, say M here.



config SERIAL_8250_PXA

	tristate "PXA serial port support"

	depends on SERIAL_8250

	depends on ARCH_PXA || ARCH_MMP

	help

	  If you have a machine based on an Intel XScale PXA2xx CPU you can

	  enable its onboard serial ports by enabling this option. The option is

	  applicable to both devicetree and legacy boards, and early console is

	  part of its support.



config SERIAL_OF_PLATFORM

	tristate "Devicetree based probing for 8250 ports"

	depends on SERIAL_8250 && OF

drivers/tty/serial/8250/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ obj-$(CONFIG_SERIAL_8250_INGENIC) += 8250_ingenic.o 
obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o

obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o

obj-$(CONFIG_SERIAL_8250_MOXA)		+= 8250_moxa.o

obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o

obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o



CFLAGS_8250_ingenic.o += -I$(srctree)/scripts/dtc/libfdt

drivers/tty/serial/Kconfig

+15 −2
Original line number Diff line number Diff line
@@ -438,17 +438,27 @@ config SERIAL_MPSC_CONSOLE 
	  Say Y here if you want to support a serial console on a Marvell MPSC.



config SERIAL_PXA

	bool "PXA serial port support"

	bool "PXA serial port support (DEPRECATED)"

	depends on ARCH_PXA || ARCH_MMP

	select SERIAL_CORE

	select SERIAL_8250_PXA if SERIAL_8250=y

	select SERIAL_PXA_NON8250 if !SERIAL_8250=y

	help

	  If you have a machine based on an Intel XScale PXA2xx CPU you

	  can enable its onboard serial ports by enabling this option.



	  Unless you have a specific need, you should use SERIAL_8250_PXA

	  instead of this.



config SERIAL_PXA_NON8250

	bool

	depends on !SERIAL_8250



config SERIAL_PXA_CONSOLE

	bool "Console on PXA serial port"

	bool "Console on PXA serial port (DEPRECATED)"

	depends on SERIAL_PXA

	select SERIAL_CORE_CONSOLE

	select SERIAL_8250_CONSOLE if SERIAL_8250=y

	help

	  If you have enabled the serial port on the Intel XScale PXA

	  CPU you can make it the console by answering Y to this option.
@@ -460,6 +470,9 @@ config SERIAL_PXA_CONSOLE 
	  your boot loader (lilo or loadlin) about how to pass options to the

	  kernel at boot time.)



	  Unless you have a specific need, you should use SERIAL_8250_PXA

	  and SERIAL_8250_CONSOLE instead of this.



config SERIAL_SA1100

	bool "SA1100 serial port support"

	depends on ARCH_SA1100

drivers/tty/serial/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250/ 
obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o

obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o

obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o

obj-$(CONFIG_SERIAL_PXA) += pxa.o

obj-$(CONFIG_SERIAL_PXA_NON8250) += pxa.o

obj-$(CONFIG_SERIAL_PNX8XXX) += pnx8xxx_uart.o

obj-$(CONFIG_SERIAL_SA1100) += sa1100.o

obj-$(CONFIG_SERIAL_BCM63XX) += bcm63xx_uart.o