Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 280df6b3 authored by Jamie Iles's avatar Jamie Iles Committed by Grant Likely
Browse files

basic_mmio_gpio: split into a gpio library and platform device 

Allow GPIO_BASIC_MMIO_CORE to be used to provide an accessor library
for implementing GPIO drivers whilst abstracting the register access
detail.  Based on a patch from Anton Vorontsov[1] and adapted to allow
bgpio_chip to be embedded in another structure.

Changes since v1:
	- Register the gpio_chip in the platform device probe

1. https://lkml.org/lkml/2011/4/19/401



Signed-off-by: default avatarAnton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: default avatarJamie Iles <jamie@jamieiles.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent e849dc04

drivers/gpio/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -70,8 +70,14 @@ config GPIO_MAX730X 


comment "Memory mapped GPIO drivers:"



config GPIO_BASIC_MMIO_CORE

	tristate

	help

	  Provides core functionality for basic memory-mapped GPIO controllers.



config GPIO_BASIC_MMIO

	tristate "Basic memory-mapped GPIO controllers support"

	select GPIO_BASIC_MMIO_CORE

	help

	  Say yes here to support basic memory-mapped GPIO controllers.

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o 


obj-$(CONFIG_GPIO_ADP5520)	+= adp5520-gpio.o

obj-$(CONFIG_GPIO_ADP5588)	+= adp5588-gpio.o

obj-$(CONFIG_GPIO_BASIC_MMIO_CORE)	+= basic_mmio_gpio.o

obj-$(CONFIG_GPIO_BASIC_MMIO)	+= basic_mmio_gpio.o

obj-$(CONFIG_GPIO_LANGWELL)	+= langwell_gpio.o

obj-$(CONFIG_GPIO_MAX730X)	+= max730x.o

drivers/gpio/basic_mmio_gpio.c

+169 −148
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.` 
 */



#include <linux/init.h>

#include <linux/err.h>

#include <linux/bug.h>

#include <linux/kernel.h>

#include <linux/module.h>
@@ -61,44 +62,6 @@ o ` ~~~~\___/~~~~ ` controller in FPGA is ,.` 
#include <linux/mod_devicetable.h>

#include <linux/basic_mmio_gpio.h>



struct bgpio_chip {

	struct gpio_chip gc;



	unsigned long (*read_reg)(void __iomem *reg);

	void (*write_reg)(void __iomem *reg, unsigned long data);



	void __iomem *reg_dat;

	void __iomem *reg_set;

	void __iomem *reg_clr;

	void __iomem *reg_dir;



	/* Number of bits (GPIOs): <register width> * 8. */

	int bits;



	/*

	 * Some GPIO controllers work with the big-endian bits notation,

	 * e.g. in a 8-bits register, GPIO7 is the least significant bit.

	 */

	unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);



	/*

	 * Used to lock bgpio_chip->data. Also, this is needed to keep

	 * shadowed and real data registers writes together.

	 */

	spinlock_t lock;



	/* Shadowed data register to clear/set bits safely. */

	unsigned long data;



	/* Shadowed direction registers to clear/set direction safely. */

	unsigned long dir;

};



static struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)

{

	return container_of(gc, struct bgpio_chip, gc);

}



static void bgpio_write8(void __iomem *reg, unsigned long data)

{

	writeb(data, reg);
@@ -284,20 +247,10 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val) 
	return 0;

}



static void __iomem *bgpio_request_and_map(struct device *dev,

					   struct resource *res)

static int bgpio_setup_accessors(struct device *dev,

				 struct bgpio_chip *bgc,

				 bool be)

{

	if (!devm_request_mem_region(dev, res->start, resource_size(res),

				     res->name ?: "mmio_gpio"))

		return NULL;



	return devm_ioremap(dev, res->start, resource_size(res));

}



static int bgpio_setup_accessors(struct platform_device *pdev,

				 struct bgpio_chip *bgc)

{

	const struct platform_device_id *platid = platform_get_device_id(pdev);



	switch (bgc->bits) {

	case 8:
@@ -319,13 +272,11 @@ static int bgpio_setup_accessors(struct platform_device *pdev, 
		break;

#endif /* BITS_PER_LONG >= 64 */

	default:

		dev_err(&pdev->dev, "unsupported data width %u bits\n",

			bgc->bits);

		dev_err(dev, "unsupported data width %u bits\n", bgc->bits);

		return -EINVAL;

	}



	bgc->pin2mask = strcmp(platid->name, "basic-mmio-gpio-be") ?

		bgpio_pin2mask : bgpio_pin2mask_be;

	bgc->pin2mask = be ? bgpio_pin2mask_be : bgpio_pin2mask;



	return 0;

}
@@ -352,51 +303,22 @@ static int bgpio_setup_accessors(struct platform_device *pdev, 
 *	- an input direction register (named "dirin") where a 1 bit indicates

 *	the GPIO is an input.

 */

static int bgpio_setup_io(struct platform_device *pdev,

			  struct bgpio_chip *bgc)

static int bgpio_setup_io(struct bgpio_chip *bgc,

			  void __iomem *dat,

			  void __iomem *set,

			  void __iomem *clr)

{

	struct resource *res_set;

	struct resource *res_clr;

	struct resource *res_dat;

	resource_size_t dat_sz;



	res_dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");

	if (!res_dat)

		return -EINVAL;



	dat_sz = resource_size(res_dat);

	if (!is_power_of_2(dat_sz))

		return -EINVAL;



	bgc->bits = dat_sz * 8;

	if (bgc->bits > BITS_PER_LONG)

		return -EINVAL;



	bgc->reg_dat = bgpio_request_and_map(&pdev->dev, res_dat);

	bgc->reg_dat = dat;

	if (!bgc->reg_dat)

		return -ENOMEM;



	res_set = platform_get_resource_byname(pdev, IORESOURCE_MEM, "set");

	res_clr = platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr");

	if (res_set && res_clr) {

		if (resource_size(res_set) != resource_size(res_clr) ||

		    resource_size(res_set) != resource_size(res_dat))

		return -EINVAL;



		bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);

		bgc->reg_clr = bgpio_request_and_map(&pdev->dev, res_clr);

		if (!bgc->reg_set || !bgc->reg_clr)

			return -ENOMEM;



	if (set && clr) {

		bgc->reg_set = set;

		bgc->reg_clr = clr;

		bgc->gc.set = bgpio_set_with_clear;

	} else if (res_set && !res_clr) {

		if (resource_size(res_set) != resource_size(res_dat))

			return -EINVAL;



		bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);

		if (!bgc->reg_set)

			return -ENOMEM;



	} else if (set && !clr) {

		bgc->reg_set = set;

		bgc->gc.set = bgpio_set_set;

	} else {

		bgc->gc.set = bgpio_set;
@@ -407,27 +329,18 @@ static int bgpio_setup_io(struct platform_device *pdev, 
	return 0;

}



static int bgpio_setup_direction(struct platform_device *pdev,

				 struct bgpio_chip *bgc)

static int bgpio_setup_direction(struct bgpio_chip *bgc,

				 void __iomem *dirout,

				 void __iomem *dirin)

{

	struct resource *res_dirout;

	struct resource *res_dirin;



	res_dirout = platform_get_resource_byname(pdev, IORESOURCE_MEM,

						  "dirout");

	res_dirin = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirin");

	if (res_dirout && res_dirin) {

	if (dirout && dirin) {

		return -EINVAL;

	} else if (res_dirout) {

		bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirout);

		if (!bgc->reg_dir)

			return -ENOMEM;

	} else if (dirout) {

		bgc->reg_dir = dirout;

		bgc->gc.direction_output = bgpio_dir_out;

		bgc->gc.direction_input = bgpio_dir_in;

	} else if (res_dirin) {

		bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirin);

		if (!bgc->reg_dir)

			return -ENOMEM;

	} else if (dirin) {

		bgc->reg_dir = dirin;

		bgc->gc.direction_output = bgpio_dir_out_inv;

		bgc->gc.direction_input = bgpio_dir_in_inv;

	} else {
@@ -438,60 +351,166 @@ static int bgpio_setup_direction(struct platform_device *pdev, 
	return 0;

}



static int __devinit bgpio_probe(struct platform_device *pdev)

int __devexit bgpio_remove(struct bgpio_chip *bgc)

{

	int err = gpiochip_remove(&bgc->gc);



	kfree(bgc);



	return err;

}

EXPORT_SYMBOL_GPL(bgpio_remove);



int __devinit bgpio_init(struct bgpio_chip *bgc,

			 struct device *dev,

			 unsigned long sz,

			 void __iomem *dat,

			 void __iomem *set,

			 void __iomem *clr,

			 void __iomem *dirout,

			 void __iomem *dirin,

			 bool big_endian)

{

	struct device *dev = &pdev->dev;

	struct bgpio_pdata *pdata = dev_get_platdata(dev);

	struct bgpio_chip *bgc;

	int ret;

	int ngpio;



	bgc = devm_kzalloc(dev, sizeof(*bgc), GFP_KERNEL);

	if (!bgc)

		return -ENOMEM;

	if (!is_power_of_2(sz))

		return -EINVAL;



	ret = bgpio_setup_io(pdev, bgc);

	if (ret)

		return ret;

	bgc->bits = sz * 8;

	if (bgc->bits > BITS_PER_LONG)

		return -EINVAL;



	ngpio = bgc->bits;

	if (pdata) {

		bgc->gc.base = pdata->base;

		if (pdata->ngpio > 0)

			ngpio = pdata->ngpio;

	} else {

	spin_lock_init(&bgc->lock);

	bgc->gc.dev = dev;

	bgc->gc.label = dev_name(dev);

	bgc->gc.base = -1;

	}

	bgc->gc.ngpio = bgc->bits;



	ret = bgpio_setup_accessors(pdev, bgc);

	ret = bgpio_setup_io(bgc, dat, set, clr);

	if (ret)

		return ret;



	spin_lock_init(&bgc->lock);

	ret = bgpio_setup_direction(pdev, bgc);

	ret = bgpio_setup_accessors(dev, bgc, big_endian);

	if (ret)

		return ret;



	ret = bgpio_setup_direction(bgc, dirout, dirin);

	if (ret)

		return ret;



	bgc->data = bgc->read_reg(bgc->reg_dat);



	bgc->gc.ngpio = ngpio;

	bgc->gc.dev = dev;

	bgc->gc.label = dev_name(dev);

	return ret;

}

EXPORT_SYMBOL_GPL(bgpio_init);



	platform_set_drvdata(pdev, bgc);

#ifdef CONFIG_GPIO_BASIC_MMIO



	ret = gpiochip_add(&bgc->gc);

	if (ret)

		dev_err(dev, "gpiochip_add() failed: %d\n", ret);

static void __iomem *bgpio_map(struct platform_device *pdev,

			       const char *name,

			       resource_size_t sane_sz,

			       int *err)

{

	struct device *dev = &pdev->dev;

	struct resource *r;

	resource_size_t start;

	resource_size_t sz;

	void __iomem *ret;



	*err = 0;



	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);

	if (!r)

		return NULL;



	sz = resource_size(r);

	if (sz != sane_sz) {

		*err = -EINVAL;

		return NULL;

	}



	start = r->start;

	if (!devm_request_mem_region(dev, start, sz, r->name)) {

		*err = -EBUSY;

		return NULL;

	}



	ret = devm_ioremap(dev, start, sz);

	if (!ret) {

		*err = -ENOMEM;

		return NULL;

	}



	return ret;

}



static int __devexit bgpio_remove(struct platform_device *pdev)

static int __devinit bgpio_pdev_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct resource *r;

	void __iomem *dat;

	void __iomem *set;

	void __iomem *clr;

	void __iomem *dirout;

	void __iomem *dirin;

	unsigned long sz;

	bool be;

	int err;

	struct bgpio_chip *bgc;

	struct bgpio_pdata *pdata = dev_get_platdata(dev);



	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");

	if (!r)

		return -EINVAL;



	sz = resource_size(r);



	dat = bgpio_map(pdev, "dat", sz, &err);

	if (!dat)

		return err ? err : -EINVAL;



	set = bgpio_map(pdev, "set", sz, &err);

	if (err)

		return err;



	clr = bgpio_map(pdev, "clr", sz, &err);

	if (err)

		return err;



	dirout = bgpio_map(pdev, "dirout", sz, &err);

	if (err)

		return err;



	dirin = bgpio_map(pdev, "dirin", sz, &err);

	if (err)

		return err;



	be = !strcmp(platform_get_device_id(pdev)->name, "basic-mmio-gpio-be");



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

	if (!bgc)

		return -ENOMEM;



	err = bgpio_init(bgc, dev, sz, dat, set, clr, dirout, dirin, be);

	if (err)

		return err;



	if (pdata) {

		bgc->gc.base = pdata->base;

		if (pdata->ngpio > 0)

			bgc->gc.ngpio = pdata->ngpio;

	}



	platform_set_drvdata(pdev, bgc);



	return gpiochip_add(&bgc->gc);

}



static int __devexit bgpio_pdev_remove(struct platform_device *pdev)

{

	struct bgpio_chip *bgc = platform_get_drvdata(pdev);



	return gpiochip_remove(&bgc->gc);

	return bgpio_remove(bgc);

}



static const struct platform_device_id bgpio_id_table[] = {
@@ -506,21 +525,23 @@ static struct platform_driver bgpio_driver = { 
		.name = "basic-mmio-gpio",

	},

	.id_table = bgpio_id_table,

	.probe = bgpio_probe,

	.remove = __devexit_p(bgpio_remove),

	.probe = bgpio_pdev_probe,

	.remove = __devexit_p(bgpio_pdev_remove),

};



static int __init bgpio_init(void)

static int __init bgpio_platform_init(void)

{

	return platform_driver_register(&bgpio_driver);

}

module_init(bgpio_init);

module_init(bgpio_platform_init);



static void __exit bgpio_exit(void)

static void __exit bgpio_platform_exit(void)

{

	platform_driver_unregister(&bgpio_driver);

}

module_exit(bgpio_exit);

module_exit(bgpio_platform_exit);



#endif /* CONFIG_GPIO_BASIC_MMIO */



MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");

MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@gmail.com>");

include/linux/basic_mmio_gpio.h

+55 −0
Original line number Diff line number Diff line
@@ -13,9 +13,64 @@ 
#ifndef __BASIC_MMIO_GPIO_H

#define __BASIC_MMIO_GPIO_H



#include <linux/gpio.h>

#include <linux/types.h>

#include <linux/compiler.h>



struct bgpio_pdata {

	int base;

	int ngpio;

};



struct device;



struct bgpio_chip {

	struct gpio_chip gc;



	unsigned long (*read_reg)(void __iomem *reg);

	void (*write_reg)(void __iomem *reg, unsigned long data);



	void __iomem *reg_dat;

	void __iomem *reg_set;

	void __iomem *reg_clr;

	void __iomem *reg_dir;



	/* Number of bits (GPIOs): <register width> * 8. */

	int bits;



	/*

	 * Some GPIO controllers work with the big-endian bits notation,

	 * e.g. in a 8-bits register, GPIO7 is the least significant bit.

	 */

	unsigned long (*pin2mask)(struct bgpio_chip *bgc, unsigned int pin);



	/*

	 * Used to lock bgpio_chip->data. Also, this is needed to keep

	 * shadowed and real data registers writes together.

	 */

	spinlock_t lock;



	/* Shadowed data register to clear/set bits safely. */

	unsigned long data;



	/* Shadowed direction registers to clear/set direction safely. */

	unsigned long dir;

};



static inline struct bgpio_chip *to_bgpio_chip(struct gpio_chip *gc)

{

	return container_of(gc, struct bgpio_chip, gc);

}



int __devexit bgpio_remove(struct bgpio_chip *bgc);

int __devinit bgpio_init(struct bgpio_chip *bgc,

			 struct device *dev,

			 unsigned long sz,

			 void __iomem *dat,

			 void __iomem *set,

			 void __iomem *clr,

			 void __iomem *dirout,

			 void __iomem *dirin,

			 bool big_endian);



#endif /* __BASIC_MMIO_GPIO_H */