Commit 88d31f83 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpio: sim: don't fiddle with GPIOLIB private members 



We access internals of struct gpio_device and struct gpio_desc because
it's easier but it can actually be avoided and we're working towards a
better encapsulation of GPIO data structures across the kernel so let's
start at home.

Instead of checking gpio_desc flags, let's just track the requests of
GPIOs in the driver. We also already store the information about
direction of simulated lines.

For kobjects needed by sysfs callbacks: we can iterate over the children
devices of the top-level platform device and compare their fwnodes
against the one passed to the init function from probe.

While at it: fix one line break and remove the untrue part about
configfs callbacks using dev_get_drvdata() from a comment.

Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent 9a249ec8

drivers/gpio/gpio-sim.c

+51 −19
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/completion.h>

#include <linux/configfs.h>

#include <linux/device.h>

#include <linux/gpio/consumer.h>

#include <linux/gpio/driver.h>

#include <linux/gpio/machine.h>

#include <linux/idr.h>
@@ -30,8 +31,6 @@ 
#include <linux/string_helpers.h>

#include <linux/sysfs.h>



#include "gpiolib.h"



#define GPIO_SIM_NGPIO_MAX	1024

#define GPIO_SIM_PROP_MAX	4 /* Max 3 properties + sentinel. */

#define GPIO_SIM_NUM_ATTRS	3 /* value, pull and sentinel */
@@ -40,6 +39,8 @@ static DEFINE_IDA(gpio_sim_ida); 


struct gpio_sim_chip {

	struct gpio_chip gc;

	struct device *dev;

	unsigned long *request_map;

	unsigned long *direction_map;

	unsigned long *value_map;

	unsigned long *pull_map;
@@ -63,16 +64,11 @@ static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 
			       unsigned int offset, int value)

{

	int irq, irq_type, ret;

	struct gpio_desc *desc;

	struct gpio_chip *gc;



	gc = &chip->gc;

	desc = &gc->gpiodev->descs[offset];



	guard(mutex)(&chip->lock);



	if (test_bit(FLAG_REQUESTED, &desc->flags) &&

	    !test_bit(FLAG_IS_OUT, &desc->flags)) {

	if (test_bit(offset, chip->request_map) &&

	    test_bit(offset, chip->direction_map)) {

		if (value == !!test_bit(offset, chip->value_map))

			goto set_pull;
@@ -99,8 +95,8 @@ static int gpio_sim_apply_pull(struct gpio_sim_chip *chip, 


set_value:

	/* Change the value unless we're actively driving the line. */

	if (!test_bit(FLAG_REQUESTED, &desc->flags) ||

	    !test_bit(FLAG_IS_OUT, &desc->flags))

	if (!test_bit(offset, chip->request_map) ||

	    test_bit(offset, chip->direction_map))

		__assign_bit(offset, chip->value_map, value);



set_pull:
@@ -180,8 +176,8 @@ static int gpio_sim_get_direction(struct gpio_chip *gc, unsigned int offset) 
	return direction ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;

}



static int gpio_sim_set_config(struct gpio_chip *gc,

				  unsigned int offset, unsigned long config)

static int gpio_sim_set_config(struct gpio_chip *gc, unsigned int offset,

			       unsigned long config)

{

	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
@@ -204,13 +200,25 @@ static int gpio_sim_to_irq(struct gpio_chip *gc, unsigned int offset) 
	return irq_create_mapping(chip->irq_sim, offset);

}



static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)

static int gpio_sim_request(struct gpio_chip *gc, unsigned int offset)

{

	struct gpio_sim_chip *chip = gpiochip_get_data(gc);



	scoped_guard(mutex, &chip->lock)

		__set_bit(offset, chip->request_map);



	return 0;

}



static void gpio_sim_free(struct gpio_chip *gc, unsigned int offset)

{

	struct gpio_sim_chip *chip = gpiochip_get_data(gc);



	scoped_guard(mutex, &chip->lock) {

		__assign_bit(offset, chip->value_map,

			     !!test_bit(offset, chip->pull_map));

		__clear_bit(offset, chip->request_map);

	}

}



static ssize_t gpio_sim_sysfs_val_show(struct device *dev,
@@ -282,6 +290,13 @@ static void gpio_sim_mutex_destroy(void *data) 
	mutex_destroy(lock);

}



static void gpio_sim_put_device(void *data)

{

	struct device *dev = data;



	put_device(dev);

}



static void gpio_sim_dispose_mappings(void *data)

{

	struct gpio_sim_chip *chip = data;
@@ -295,7 +310,7 @@ static void gpio_sim_sysfs_remove(void *data) 
{

	struct gpio_sim_chip *chip = data;



	sysfs_remove_groups(&chip->gc.gpiodev->dev.kobj, chip->attr_groups);

	sysfs_remove_groups(&chip->dev->kobj, chip->attr_groups);

}



static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip)
@@ -352,14 +367,18 @@ static int gpio_sim_setup_sysfs(struct gpio_sim_chip *chip) 
		chip->attr_groups[i] = attr_group;

	}



	ret = sysfs_create_groups(&chip->gc.gpiodev->dev.kobj,

				  chip->attr_groups);

	ret = sysfs_create_groups(&chip->dev->kobj, chip->attr_groups);

	if (ret)

		return ret;



	return devm_add_action_or_reset(dev, gpio_sim_sysfs_remove, chip);

}



static int gpio_sim_dev_match_fwnode(struct device *dev, void *data)

{

	return device_match_fwnode(dev, data);

}



static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev)

{

	struct gpio_sim_chip *chip;
@@ -387,6 +406,10 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 
	if (!chip)

		return -ENOMEM;



	chip->request_map = devm_bitmap_zalloc(dev, num_lines, GFP_KERNEL);

	if (!chip->request_map)

		return -ENOMEM;



	chip->direction_map = devm_bitmap_alloc(dev, num_lines, GFP_KERNEL);

	if (!chip->direction_map)

		return -ENOMEM;
@@ -432,6 +455,7 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 
	gc->get_direction = gpio_sim_get_direction;

	gc->set_config = gpio_sim_set_config;

	gc->to_irq = gpio_sim_to_irq;

	gc->request = gpio_sim_request;

	gc->free = gpio_sim_free;

	gc->can_sleep = true;
@@ -439,8 +463,16 @@ static int gpio_sim_add_bank(struct fwnode_handle *swnode, struct device *dev) 
	if (ret)

		return ret;



	/* Used by sysfs and configfs callbacks. */

	dev_set_drvdata(&gc->gpiodev->dev, chip);

	chip->dev = device_find_child(dev, swnode, gpio_sim_dev_match_fwnode);

	if (!chip->dev)

		return -ENODEV;



	ret = devm_add_action_or_reset(dev, gpio_sim_put_device, chip->dev);

	if (ret)

		return ret;



	/* Used by sysfs callbacks. */

	dev_set_drvdata(chip->dev, chip);



	return gpio_sim_setup_sysfs(chip);

}