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Commit 878e7556 authored by Steven A. Falco's avatar Steven A. Falco Committed by Josh Boyer
Browse files

powerpc/4xx: Add PowerPC 4xx GPIO driver 



This patch adds support for the GPIO functions of PPC40x and PPC44x
SOCs.

Signed-off-by: default avatarSteve Falco <sfalco@harris.com>
Acked-by: default avatarStefan Roese <sr@denx.de>
Acked-by: default avatarSean MacLennan <smaclennan@pikatech.com>
Signed-off-by: default avatarJosh Boyer <jwboyer@linux.vnet.ibm.com>
parent 9fa126da

arch/powerpc/platforms/40x/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -169,6 +169,14 @@ config STB03xxx 
	select IBM405_ERR77

	select IBM405_ERR51



config PPC4xx_GPIO

	bool "PPC4xx GPIO support"

	depends on 40x

	select ARCH_REQUIRE_GPIOLIB

	select GENERIC_GPIO

	help

	  Enable gpiolib support for ppc40x based boards



# 40x errata/workaround config symbols, selected by the CPU models above



# All 405-based cores up until the 405GPR and 405EP have this errata.

arch/powerpc/platforms/44x/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -167,6 +167,14 @@ config PPC44x_SIMPLE 
	help

	  This option enables the simple PowerPC 44x platform support.



config PPC4xx_GPIO

	bool "PPC4xx GPIO support"

	depends on 44x

	select ARCH_REQUIRE_GPIOLIB

	select GENERIC_GPIO

	help

	  Enable gpiolib support for ppc440 based boards



# 44x specific CPU modules, selected based on the board above.

config 440EP

	bool

arch/powerpc/sysdev/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ obj-$(CONFIG_OF_RTC) += of_rtc.o 
ifeq ($(CONFIG_PCI),y)

obj-$(CONFIG_4xx)		+= ppc4xx_pci.o

endif

obj-$(CONFIG_PPC4xx_GPIO)	+= ppc4xx_gpio.o



obj-$(CONFIG_CPM)		+= cpm_common.o

obj-$(CONFIG_CPM2)		+= cpm2.o cpm2_pic.o

arch/powerpc/sysdev/ppc4xx_gpio.c

0 → 100644
+217 −0
Original line number Diff line number Diff line 
/*

 * PPC4xx gpio driver

 *

 * Copyright (c) 2008 Harris Corporation

 * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix

 * Copyright (c) MontaVista Software, Inc. 2008.

 *

 * Author: Steve Falco <sfalco@harris.com>

 *

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

 * it under the terms of the GNU General Public License version 2

 * as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */



#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/spinlock.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/of_gpio.h>

#include <linux/gpio.h>

#include <linux/types.h>



#define GPIO_MASK(gpio)		(0x80000000 >> (gpio))

#define GPIO_MASK2(gpio)	(0xc0000000 >> ((gpio) * 2))



/* Physical GPIO register layout */

struct ppc4xx_gpio {

	__be32 or;

	__be32 tcr;

	__be32 osrl;

	__be32 osrh;

	__be32 tsrl;

	__be32 tsrh;

	__be32 odr;

	__be32 ir;

	__be32 rr1;

	__be32 rr2;

	__be32 rr3;

	__be32 reserved1;

	__be32 isr1l;

	__be32 isr1h;

	__be32 isr2l;

	__be32 isr2h;

	__be32 isr3l;

	__be32 isr3h;

};



struct ppc4xx_gpio_chip {

	struct of_mm_gpio_chip mm_gc;

	spinlock_t lock;

};



/*

 * GPIO LIB API implementation for GPIOs

 *

 * There are a maximum of 32 gpios in each gpio controller.

 */



static inline struct ppc4xx_gpio_chip *

to_ppc4xx_gpiochip(struct of_mm_gpio_chip *mm_gc)

{

	return container_of(mm_gc, struct ppc4xx_gpio_chip, mm_gc);

}



static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;



	return in_be32(&regs->ir) & GPIO_MASK(gpio);

}



static inline void

__ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;



	if (val)

		setbits32(&regs->or, GPIO_MASK(gpio));

	else

		clrbits32(&regs->or, GPIO_MASK(gpio));

}



static void

ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);

	unsigned long flags;



	spin_lock_irqsave(&chip->lock, flags);



	__ppc4xx_gpio_set(gc, gpio, val);



	spin_unlock_irqrestore(&chip->lock, flags);



	pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);

}



static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);

	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;

	unsigned long flags;



	spin_lock_irqsave(&chip->lock, flags);



	/* Disable open-drain function */

	clrbits32(&regs->odr, GPIO_MASK(gpio));



	/* Float the pin */

	clrbits32(&regs->tcr, GPIO_MASK(gpio));



	/* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */

	if (gpio < 16) {

		clrbits32(&regs->osrl, GPIO_MASK2(gpio));

		clrbits32(&regs->tsrl, GPIO_MASK2(gpio));

	} else {

		clrbits32(&regs->osrh, GPIO_MASK2(gpio));

		clrbits32(&regs->tsrh, GPIO_MASK2(gpio));

	}



	spin_unlock_irqrestore(&chip->lock, flags);



	return 0;

}



static int

ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)

{

	struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);

	struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);

	struct ppc4xx_gpio __iomem *regs = mm_gc->regs;

	unsigned long flags;



	spin_lock_irqsave(&chip->lock, flags);



	/* First set initial value */

	__ppc4xx_gpio_set(gc, gpio, val);



	/* Disable open-drain function */

	clrbits32(&regs->odr, GPIO_MASK(gpio));



	/* Drive the pin */

	setbits32(&regs->tcr, GPIO_MASK(gpio));



	/* Bits 0-15 use TSRL, bits 16-31 use TSRH */

	if (gpio < 16) {

		clrbits32(&regs->osrl, GPIO_MASK2(gpio));

		clrbits32(&regs->tsrl, GPIO_MASK2(gpio));

	} else {

		clrbits32(&regs->osrh, GPIO_MASK2(gpio));

		clrbits32(&regs->tsrh, GPIO_MASK2(gpio));

	}



	spin_unlock_irqrestore(&chip->lock, flags);



	pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);



	return 0;

}



static int __init ppc4xx_add_gpiochips(void)

{

	struct device_node *np;



	for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") {

		int ret;

		struct ppc4xx_gpio_chip *ppc4xx_gc;

		struct of_mm_gpio_chip *mm_gc;

		struct of_gpio_chip *of_gc;

		struct gpio_chip *gc;



		ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL);

		if (!ppc4xx_gc) {

			ret = -ENOMEM;

			goto err;

		}



		spin_lock_init(&ppc4xx_gc->lock);



		mm_gc = &ppc4xx_gc->mm_gc;

		of_gc = &mm_gc->of_gc;

		gc = &of_gc->gc;



		of_gc->gpio_cells = 2;

		gc->ngpio = 32;

		gc->direction_input = ppc4xx_gpio_dir_in;

		gc->direction_output = ppc4xx_gpio_dir_out;

		gc->get = ppc4xx_gpio_get;

		gc->set = ppc4xx_gpio_set;



		ret = of_mm_gpiochip_add(np, mm_gc);

		if (ret)

			goto err;

		continue;

err:

		pr_err("%s: registration failed with status %d\n",

		       np->full_name, ret);

		kfree(ppc4xx_gc);

		/* try others anyway */

	}

	return 0;

}

arch_initcall(ppc4xx_add_gpiochips);