[linux-block.git] / drivers / gpio / gpio-aggregator.c

// SPDX-License-Identifier: GPL-2.0-only
//
// GPIO Aggregator
//
// Copyright (C) 2019-2020 Glider bv

#define DRV_NAME       "gpio-aggregator"
#define pr_fmt(fmt)	DRV_NAME ": " fmt

#include <linux/bitmap.h>
#include <linux/bitops.h>
#include <linux/ctype.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/overflow.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/string.h>


/*
 * GPIO Aggregator sysfs interface
 */

struct gpio_aggregator {
	struct gpiod_lookup_table *lookups;
	struct platform_device *pdev;
	char args[];
};

static DEFINE_MUTEX(gpio_aggregator_lock);	/* protects idr */
static DEFINE_IDR(gpio_aggregator_idr);

static char *get_arg(char **args)
{
	char *start, *end;

	start = skip_spaces(*args);
	if (!*start)
		return NULL;

	if (*start == '"') {
		/* Quoted arg */
		end = strchr(++start, '"');
		if (!end)
			return ERR_PTR(-EINVAL);
	} else {
		/* Unquoted arg */
		for (end = start; *end && !isspace(*end); end++) ;
	}

	if (*end)
		*end++ = '\0';

	*args = end;
	return start;
}

static bool isrange(const char *s)
{
	size_t n;

	if (IS_ERR_OR_NULL(s))
		return false;

	while (1) {
		n = strspn(s, "0123456789");
		if (!n)
			return false;

		s += n;

		switch (*s++) {
		case '\0':
			return true;

		case '-':
		case ',':
			break;

		default:
			return false;
		}
	}
}

static int aggr_add_gpio(struct gpio_aggregator *aggr, const char *key,
			 int hwnum, unsigned int *n)
{
	struct gpiod_lookup_table *lookups;

	lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2),
			   GFP_KERNEL);
	if (!lookups)
		return -ENOMEM;

	lookups->table[*n] =
		(struct gpiod_lookup)GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0);

	(*n)++;
	memset(&lookups->table[*n], 0, sizeof(lookups->table[*n]));

	aggr->lookups = lookups;
	return 0;
}

static int aggr_parse(struct gpio_aggregator *aggr)
{
	char *args = aggr->args;
	unsigned long *bitmap;
	unsigned int i, n = 0;
	char *name, *offsets;
	int error = 0;

	bitmap = bitmap_alloc(ARCH_NR_GPIOS, GFP_KERNEL);
	if (!bitmap)
		return -ENOMEM;

	for (name = get_arg(&args), offsets = get_arg(&args); name;
	     offsets = get_arg(&args)) {
		if (IS_ERR(name)) {
			pr_err("Cannot get GPIO specifier: %pe\n", name);
			error = PTR_ERR(name);
			goto free_bitmap;
		}

		if (!isrange(offsets)) {
			/* Named GPIO line */
			error = aggr_add_gpio(aggr, name, U16_MAX, &n);
			if (error)
				goto free_bitmap;

			name = offsets;
			continue;
		}

		/* GPIO chip + offset(s) */
		error = bitmap_parselist(offsets, bitmap, ARCH_NR_GPIOS);
		if (error) {
			pr_err("Cannot parse %s: %d\n", offsets, error);
			goto free_bitmap;
		}

		for_each_set_bit(i, bitmap, ARCH_NR_GPIOS) {
			error = aggr_add_gpio(aggr, name, i, &n);
			if (error)
				goto free_bitmap;
		}

		name = get_arg(&args);
	}

	if (!n) {
		pr_err("No GPIOs specified\n");
		error = -EINVAL;
	}

free_bitmap:
	bitmap_free(bitmap);
	return error;
}

static ssize_t new_device_store(struct device_driver *driver, const char *buf,
				size_t count)
{
	struct gpio_aggregator *aggr;
	struct platform_device *pdev;
	int res, id;

	/* kernfs guarantees string termination, so count + 1 is safe */
	aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL);
	if (!aggr)
		return -ENOMEM;

	memcpy(aggr->args, buf, count + 1);

	aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
				GFP_KERNEL);
	if (!aggr->lookups) {
		res = -ENOMEM;
		goto free_ga;
	}

	mutex_lock(&gpio_aggregator_lock);
	id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
	mutex_unlock(&gpio_aggregator_lock);

	if (id < 0) {
		res = id;
		goto free_table;
	}

	aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id);
	if (!aggr->lookups->dev_id) {
		res = -ENOMEM;
		goto remove_idr;
	}

	res = aggr_parse(aggr);
	if (res)
		goto free_dev_id;

	gpiod_add_lookup_table(aggr->lookups);

	pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0);
	if (IS_ERR(pdev)) {
		res = PTR_ERR(pdev);
		goto remove_table;
	}

	aggr->pdev = pdev;
	return count;

remove_table:
	gpiod_remove_lookup_table(aggr->lookups);
free_dev_id:
	kfree(aggr->lookups->dev_id);
remove_idr:
	mutex_lock(&gpio_aggregator_lock);
	idr_remove(&gpio_aggregator_idr, id);
	mutex_unlock(&gpio_aggregator_lock);
free_table:
	kfree(aggr->lookups);
free_ga:
	kfree(aggr);
	return res;
}

static DRIVER_ATTR_WO(new_device);

static void gpio_aggregator_free(struct gpio_aggregator *aggr)
{
	platform_device_unregister(aggr->pdev);
	gpiod_remove_lookup_table(aggr->lookups);
	kfree(aggr->lookups->dev_id);
	kfree(aggr->lookups);
	kfree(aggr);
}

static ssize_t delete_device_store(struct device_driver *driver,
				   const char *buf, size_t count)
{
	struct gpio_aggregator *aggr;
	unsigned int id;
	int error;

	if (!str_has_prefix(buf, DRV_NAME "."))
		return -EINVAL;

	error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id);
	if (error)
		return error;

	mutex_lock(&gpio_aggregator_lock);
	aggr = idr_remove(&gpio_aggregator_idr, id);
	mutex_unlock(&gpio_aggregator_lock);
	if (!aggr)
		return -ENOENT;

	gpio_aggregator_free(aggr);
	return count;
}
static DRIVER_ATTR_WO(delete_device);

static struct attribute *gpio_aggregator_attrs[] = {
	&driver_attr_new_device.attr,
	&driver_attr_delete_device.attr,
	NULL,
};
ATTRIBUTE_GROUPS(gpio_aggregator);

static int __exit gpio_aggregator_idr_remove(int id, void *p, void *data)
{
	gpio_aggregator_free(p);
	return 0;
}

static void __exit gpio_aggregator_remove_all(void)
{
	mutex_lock(&gpio_aggregator_lock);
	idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL);
	idr_destroy(&gpio_aggregator_idr);
	mutex_unlock(&gpio_aggregator_lock);
}


/*
 *  GPIO Forwarder
 */

struct gpiochip_fwd {
	struct gpio_chip chip;
	struct gpio_desc **descs;
	union {
		struct mutex mlock;	/* protects tmp[] if can_sleep */
		spinlock_t slock;	/* protects tmp[] if !can_sleep */
	};
	unsigned long tmp[];		/* values and descs for multiple ops */
};

static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	return gpiod_get_direction(fwd->descs[offset]);
}

static int gpio_fwd_direction_input(struct gpio_chip *chip, unsigned int offset)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	return gpiod_direction_input(fwd->descs[offset]);
}

static int gpio_fwd_direction_output(struct gpio_chip *chip,
				     unsigned int offset, int value)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	return gpiod_direction_output(fwd->descs[offset], value);
}

static int gpio_fwd_get(struct gpio_chip *chip, unsigned int offset)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	return gpiod_get_value(fwd->descs[offset]);
}

static int gpio_fwd_get_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,
				 unsigned long *bits)
{
	struct gpio_desc **descs;
	unsigned long *values;
	unsigned int i, j = 0;
	int error;

	/* Both values bitmap and desc pointers are stored in tmp[] */
	values = &fwd->tmp[0];
	descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];

	bitmap_clear(values, 0, fwd->chip.ngpio);
	for_each_set_bit(i, mask, fwd->chip.ngpio)
		descs[j++] = fwd->descs[i];

	error = gpiod_get_array_value(j, descs, NULL, values);
	if (error)
		return error;

	j = 0;
	for_each_set_bit(i, mask, fwd->chip.ngpio)
		__assign_bit(i, bits, test_bit(j++, values));

	return 0;
}

static int gpio_fwd_get_multiple_locked(struct gpio_chip *chip,
					unsigned long *mask, unsigned long *bits)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
	unsigned long flags;
	int error;

	if (chip->can_sleep) {
		mutex_lock(&fwd->mlock);
		error = gpio_fwd_get_multiple(fwd, mask, bits);
		mutex_unlock(&fwd->mlock);
	} else {
		spin_lock_irqsave(&fwd->slock, flags);
		error = gpio_fwd_get_multiple(fwd, mask, bits);
		spin_unlock_irqrestore(&fwd->slock, flags);
	}

	return error;
}

static void gpio_fwd_set(struct gpio_chip *chip, unsigned int offset, int value)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	gpiod_set_value(fwd->descs[offset], value);
}

static void gpio_fwd_set_multiple(struct gpiochip_fwd *fwd, unsigned long *mask,
				  unsigned long *bits)
{
	struct gpio_desc **descs;
	unsigned long *values;
	unsigned int i, j = 0;

	/* Both values bitmap and desc pointers are stored in tmp[] */
	values = &fwd->tmp[0];
	descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];

	for_each_set_bit(i, mask, fwd->chip.ngpio) {
		__assign_bit(j, values, test_bit(i, bits));
		descs[j++] = fwd->descs[i];
	}

	gpiod_set_array_value(j, descs, NULL, values);
}

static void gpio_fwd_set_multiple_locked(struct gpio_chip *chip,
					 unsigned long *mask, unsigned long *bits)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
	unsigned long flags;

	if (chip->can_sleep) {
		mutex_lock(&fwd->mlock);
		gpio_fwd_set_multiple(fwd, mask, bits);
		mutex_unlock(&fwd->mlock);
	} else {
		spin_lock_irqsave(&fwd->slock, flags);
		gpio_fwd_set_multiple(fwd, mask, bits);
		spin_unlock_irqrestore(&fwd->slock, flags);
	}
}

static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
			       unsigned long config)
{
	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	return gpiod_set_config(fwd->descs[offset], config);
}

/**
 * gpiochip_fwd_create() - Create a new GPIO forwarder
 * @dev: Parent device pointer
 * @ngpios: Number of GPIOs in the forwarder.
 * @descs: Array containing the GPIO descriptors to forward to.
 *         This array must contain @ngpios entries, and must not be deallocated
 *         before the forwarder has been destroyed again.
 *
 * This function creates a new gpiochip, which forwards all GPIO operations to
 * the passed GPIO descriptors.
 *
 * Return: An opaque object pointer, or an ERR_PTR()-encoded negative error
 *         code on failure.
 */
static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,
						unsigned int ngpios,
						struct gpio_desc *descs[])
{
	const char *label = dev_name(dev);
	struct gpiochip_fwd *fwd;
	struct gpio_chip *chip;
	unsigned int i;
	int error;

	fwd = devm_kzalloc(dev, struct_size(fwd, tmp,
			   BITS_TO_LONGS(ngpios) + ngpios), GFP_KERNEL);
	if (!fwd)
		return ERR_PTR(-ENOMEM);

	chip = &fwd->chip;

	/*
	 * If any of the GPIO lines are sleeping, then the entire forwarder
	 * will be sleeping.
	 * If any of the chips support .set_config(), then the forwarder will
	 * support setting configs.
	 */
	for (i = 0; i < ngpios; i++) {
		struct gpio_chip *parent = gpiod_to_chip(descs[i]);

		dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));

		if (gpiod_cansleep(descs[i]))
			chip->can_sleep = true;
		if (parent && parent->set_config)
			chip->set_config = gpio_fwd_set_config;
	}

	chip->label = label;
	chip->parent = dev;
	chip->owner = THIS_MODULE;
	chip->get_direction = gpio_fwd_get_direction;
	chip->direction_input = gpio_fwd_direction_input;
	chip->direction_output = gpio_fwd_direction_output;
	chip->get = gpio_fwd_get;
	chip->get_multiple = gpio_fwd_get_multiple_locked;
	chip->set = gpio_fwd_set;
	chip->set_multiple = gpio_fwd_set_multiple_locked;
	chip->base = -1;
	chip->ngpio = ngpios;
	fwd->descs = descs;

	if (chip->can_sleep)
		mutex_init(&fwd->mlock);
	else
		spin_lock_init(&fwd->slock);

	error = devm_gpiochip_add_data(dev, chip, fwd);
	if (error)
		return ERR_PTR(error);

	return fwd;
}


/*
 *  GPIO Aggregator platform device
 */

static int gpio_aggregator_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct gpio_desc **descs;
	struct gpiochip_fwd *fwd;
	int i, n;

	n = gpiod_count(dev, NULL);
	if (n < 0)
		return n;

	descs = devm_kmalloc_array(dev, n, sizeof(*descs), GFP_KERNEL);
	if (!descs)
		return -ENOMEM;

	for (i = 0; i < n; i++) {
		descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
		if (IS_ERR(descs[i]))
			return PTR_ERR(descs[i]);
	}

	fwd = gpiochip_fwd_create(dev, n, descs);
	if (IS_ERR(fwd))
		return PTR_ERR(fwd);

	platform_set_drvdata(pdev, fwd);
	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id gpio_aggregator_dt_ids[] = {
	/*
	 * Add GPIO-operated devices controlled from userspace below,
	 * or use "driver_override" in sysfs
	 */
	{},
};
MODULE_DEVICE_TABLE(of, gpio_aggregator_dt_ids);
#endif

static struct platform_driver gpio_aggregator_driver = {
	.probe = gpio_aggregator_probe,
	.driver = {
		.name = DRV_NAME,
		.groups = gpio_aggregator_groups,
		.of_match_table = of_match_ptr(gpio_aggregator_dt_ids),
	},
};

static int __init gpio_aggregator_init(void)
{
	return platform_driver_register(&gpio_aggregator_driver);
}
module_init(gpio_aggregator_init);

static void __exit gpio_aggregator_exit(void)
{
	gpio_aggregator_remove_all();
	platform_driver_unregister(&gpio_aggregator_driver);
}
module_exit(gpio_aggregator_exit);

MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
MODULE_DESCRIPTION("GPIO Aggregator");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
828546e2 GU	1	// SPDX-License-Identifier: GPL-2.0-only
	2	//
	3	// GPIO Aggregator
	4	//
	5	// Copyright (C) 2019-2020 Glider bv
	6
	7	#define DRV_NAME "gpio-aggregator"
	8	#define pr_fmt(fmt) DRV_NAME ": " fmt
	9
	10	#include <linux/bitmap.h>
	11	#include <linux/bitops.h>
	12	#include <linux/ctype.h>
ec75039d	13	#include <linux/gpio.h>
828546e2 GU	14	#include <linux/gpio/consumer.h>
	15	#include <linux/gpio/driver.h>
	16	#include <linux/gpio/machine.h>
	17	#include <linux/idr.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/mutex.h>
	21	#include <linux/overflow.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/spinlock.h>
	24	#include <linux/string.h>
	25
	26
	27	/*
	28	* GPIO Aggregator sysfs interface
	29	*/
	30
	31	struct gpio_aggregator {
	32	struct gpiod_lookup_table *lookups;
	33	struct platform_device *pdev;
	34	char args[];
	35	};
	36
	37	static DEFINE_MUTEX(gpio_aggregator_lock); /* protects idr */
	38	static DEFINE_IDR(gpio_aggregator_idr);
	39
	40	static char get_arg(char *args)
	41	{
2073ea3a	42	char start, end;
828546e2	43
2073ea3a	44	start = skip_spaces(*args);
828546e2 GU	45	if (!*start)
	46	return NULL;
	47
	48	if (*start == '"') {
	49	/* Quoted arg */
	50	end = strchr(++start, '"');
	51	if (!end)
	52	return ERR_PTR(-EINVAL);
	53	} else {
	54	/* Unquoted arg */
	55	for (end = start; end && !isspace(end); end++) ;
	56	}
	57
	58	if (*end)
	59	*end++ = '\0';
	60
	61	*args = end;
	62	return start;
	63	}
	64
	65	static bool isrange(const char *s)
	66	{
	67	size_t n;
	68
	69	if (IS_ERR_OR_NULL(s))
	70	return false;
	71
	72	while (1) {
	73	n = strspn(s, "0123456789");
	74	if (!n)
	75	return false;
	76
	77	s += n;
	78
	79	switch (*s++) {
	80	case '\0':
	81	return true;
	82
	83	case '-':
	84	case ',':
	85	break;
	86
	87	default:
	88	return false;
	89	}
	90	}
	91	}
	92
	93	static int aggr_add_gpio(struct gpio_aggregator aggr, const char key,
	94	int hwnum, unsigned int *n)
	95	{
	96	struct gpiod_lookup_table *lookups;
	97
	98	lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2),
	99	GFP_KERNEL);
	100	if (!lookups)
	101	return -ENOMEM;
	102
	103	lookups->table[*n] =
	104	(struct gpiod_lookup)GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0);
	105
	106	(*n)++;
	107	memset(&lookups->table[n], 0, sizeof(lookups->table[n]));
	108
109	aggr->lookups = lookups;
110	return 0;
111	}
112
113	static int aggr_parse(struct gpio_aggregator *aggr)
114	{
828546e2	115	char *args = aggr->args;
ec75039d GU	116	unsigned long *bitmap;
	117	unsigned int i, n = 0;
	118	char name, offsets;
	119	int error = 0;
	120
	121	bitmap = bitmap_alloc(ARCH_NR_GPIOS, GFP_KERNEL);
	122	if (!bitmap)
	123	return -ENOMEM;
828546e2 GU	124
	125	for (name = get_arg(&args), offsets = get_arg(&args); name;
	126	offsets = get_arg(&args)) {
	127	if (IS_ERR(name)) {
	128	pr_err("Cannot get GPIO specifier: %pe\n", name);
ec75039d GU	129	error = PTR_ERR(name);
ec75039d GU	130	goto free_bitmap;
828546e2 GU	131	}
	132
	133	if (!isrange(offsets)) {
	134	/* Named GPIO line */
	135	error = aggr_add_gpio(aggr, name, U16_MAX, &n);
	136	if (error)
ec75039d	137	goto free_bitmap;
828546e2 GU	138
	139	name = offsets;
	140	continue;
	141	}
	142
	143	/* GPIO chip + offset(s) */
ec75039d GU	144	error = bitmap_parselist(offsets, bitmap, ARCH_NR_GPIOS);
	145	if (error) {
	146	pr_err("Cannot parse %s: %d\n", offsets, error);
	147	goto free_bitmap;
	148	}
	149
	150	for_each_set_bit(i, bitmap, ARCH_NR_GPIOS) {
	151	error = aggr_add_gpio(aggr, name, i, &n);
	152	if (error)
	153	goto free_bitmap;
828546e2 GU	154	}
	155
	156	name = get_arg(&args);
	157	}
	158
	159	if (!n) {
	160	pr_err("No GPIOs specified\n");
ec75039d	161	error = -EINVAL;
828546e2 GU	162	}
828546e2 GU	163
ec75039d GU	164	free_bitmap:
	165	bitmap_free(bitmap);
	166	return error;
828546e2 GU	167	}
	168
	169	static ssize_t new_device_store(struct device_driver driver, const char buf,
	170	size_t count)
	171	{
	172	struct gpio_aggregator *aggr;
	173	struct platform_device *pdev;
	174	int res, id;
	175
	176	/* kernfs guarantees string termination, so count + 1 is safe */
	177	aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL);
	178	if (!aggr)
	179	return -ENOMEM;
	180
	181	memcpy(aggr->args, buf, count + 1);
	182
	183	aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1),
	184	GFP_KERNEL);
	185	if (!aggr->lookups) {
	186	res = -ENOMEM;
	187	goto free_ga;
	188	}
	189
	190	mutex_lock(&gpio_aggregator_lock);
	191	id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL);
	192	mutex_unlock(&gpio_aggregator_lock);
	193
	194	if (id < 0) {
	195	res = id;
	196	goto free_table;
	197	}
	198
	199	aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id);
	200	if (!aggr->lookups->dev_id) {
	201	res = -ENOMEM;
	202	goto remove_idr;
	203	}
	204
	205	res = aggr_parse(aggr);
	206	if (res)
	207	goto free_dev_id;
	208
	209	gpiod_add_lookup_table(aggr->lookups);
	210
	211	pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0);
	212	if (IS_ERR(pdev)) {
	213	res = PTR_ERR(pdev);
	214	goto remove_table;
	215	}
	216
	217	aggr->pdev = pdev;
	218	return count;
	219
	220	remove_table:
	221	gpiod_remove_lookup_table(aggr->lookups);
	222	free_dev_id:
	223	kfree(aggr->lookups->dev_id);
	224	remove_idr:
	225	mutex_lock(&gpio_aggregator_lock);
	226	idr_remove(&gpio_aggregator_idr, id);
	227	mutex_unlock(&gpio_aggregator_lock);
	228	free_table:
	229	kfree(aggr->lookups);
	230	free_ga:
231	kfree(aggr);
232	return res;
233	}
234
235	static DRIVER_ATTR_WO(new_device);
236
237	static void gpio_aggregator_free(struct gpio_aggregator *aggr)
238	{
239	platform_device_unregister(aggr->pdev);
240	gpiod_remove_lookup_table(aggr->lookups);
241	kfree(aggr->lookups->dev_id);
242	kfree(aggr->lookups);
243	kfree(aggr);
244	}
245
246	static ssize_t delete_device_store(struct device_driver *driver,
247	const char *buf, size_t count)
248	{
249	struct gpio_aggregator *aggr;
250	unsigned int id;
251	int error;
252
253	if (!str_has_prefix(buf, DRV_NAME "."))
254	return -EINVAL;
255
256	error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id);
257	if (error)
258	return error;
259
260	mutex_lock(&gpio_aggregator_lock);
261	aggr = idr_remove(&gpio_aggregator_idr, id);
262	mutex_unlock(&gpio_aggregator_lock);
263	if (!aggr)
264	return -ENOENT;
265
266	gpio_aggregator_free(aggr);
267	return count;
268	}
269	static DRIVER_ATTR_WO(delete_device);
270
271	static struct attribute *gpio_aggregator_attrs[] = {
272	&driver_attr_new_device.attr,
273	&driver_attr_delete_device.attr,
274	NULL,
275	};
276	ATTRIBUTE_GROUPS(gpio_aggregator);
277
278	static int __exit gpio_aggregator_idr_remove(int id, void p, void data)
279	{
280	gpio_aggregator_free(p);
281	return 0;
282	}
283
284	static void __exit gpio_aggregator_remove_all(void)
285	{
286	mutex_lock(&gpio_aggregator_lock);
287	idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL);
288	idr_destroy(&gpio_aggregator_idr);
289	mutex_unlock(&gpio_aggregator_lock);
290	}
291
292
293	/*
294	* GPIO Forwarder
295	*/
296
297	struct gpiochip_fwd {
298	struct gpio_chip chip;
299	struct gpio_desc **descs;
300	union {
301	struct mutex mlock; /* protects tmp[] if can_sleep */
302	spinlock_t slock; /* protects tmp[] if !can_sleep */
303	};
304	unsigned long tmp[]; /* values and descs for multiple ops */
305	};
306
307	static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset)
308	{
309	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
310
311	return gpiod_get_direction(fwd->descs[offset]);
312	}
313
314	static int gpio_fwd_direction_input(struct gpio_chip *chip, unsigned int offset)
315	{
316	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
317
318	return gpiod_direction_input(fwd->descs[offset]);
319	}
320
321	static int gpio_fwd_direction_output(struct gpio_chip *chip,
322	unsigned int offset, int value)
323	{
324	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
325
326	return gpiod_direction_output(fwd->descs[offset], value);
327	}
328
329	static int gpio_fwd_get(struct gpio_chip *chip, unsigned int offset)
330	{
331	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
332
333	return gpiod_get_value(fwd->descs[offset]);
334	}
335
01e8d85b	336	static int gpio_fwd_get_multiple(struct gpiochip_fwd fwd, unsigned long mask,
828546e2 GU	337	unsigned long *bits)
828546e2 GU	338	{
828546e2	339	struct gpio_desc **descs;
01e8d85b	340	unsigned long *values;
828546e2 GU	341	unsigned int i, j = 0;
	342	int error;
	343
828546e2 GU	344	/* Both values bitmap and desc pointers are stored in tmp[] */
	345	values = &fwd->tmp[0];
	346	descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];
	347
	348	bitmap_clear(values, 0, fwd->chip.ngpio);
	349	for_each_set_bit(i, mask, fwd->chip.ngpio)
	350	descs[j++] = fwd->descs[i];
	351
	352	error = gpiod_get_array_value(j, descs, NULL, values);
01e8d85b AS	353	if (error)
01e8d85b AS	354	return error;
828546e2	355
01e8d85b AS	356	j = 0;
	357	for_each_set_bit(i, mask, fwd->chip.ngpio)
	358	__assign_bit(i, bits, test_bit(j++, values));
	359
	360	return 0;
	361	}
	362
	363	static int gpio_fwd_get_multiple_locked(struct gpio_chip *chip,
	364	unsigned long mask, unsigned long bits)
	365	{
	366	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
	367	unsigned long flags;
	368	int error;
	369
	370	if (chip->can_sleep) {
	371	mutex_lock(&fwd->mlock);
	372	error = gpio_fwd_get_multiple(fwd, mask, bits);
828546e2	373	mutex_unlock(&fwd->mlock);
01e8d85b AS	374	} else {
	375	spin_lock_irqsave(&fwd->slock, flags);
	376	error = gpio_fwd_get_multiple(fwd, mask, bits);
828546e2	377	spin_unlock_irqrestore(&fwd->slock, flags);
01e8d85b	378	}
828546e2 GU	379
	380	return error;
	381	}
	382
	383	static void gpio_fwd_set(struct gpio_chip *chip, unsigned int offset, int value)
	384	{
	385	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
	386
	387	gpiod_set_value(fwd->descs[offset], value);
	388	}
	389
01e8d85b	390	static void gpio_fwd_set_multiple(struct gpiochip_fwd fwd, unsigned long mask,
828546e2 GU	391	unsigned long *bits)
828546e2 GU	392	{
828546e2	393	struct gpio_desc **descs;
01e8d85b	394	unsigned long *values;
828546e2 GU	395	unsigned int i, j = 0;
828546e2 GU	396
828546e2 GU	397	/* Both values bitmap and desc pointers are stored in tmp[] */
	398	values = &fwd->tmp[0];
	399	descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)];
	400
	401	for_each_set_bit(i, mask, fwd->chip.ngpio) {
	402	__assign_bit(j, values, test_bit(i, bits));
	403	descs[j++] = fwd->descs[i];
	404	}
	405
	406	gpiod_set_array_value(j, descs, NULL, values);
01e8d85b	407	}
828546e2	408
01e8d85b AS	409	static void gpio_fwd_set_multiple_locked(struct gpio_chip *chip,
	410	unsigned long mask, unsigned long bits)
	411	{
	412	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
	413	unsigned long flags;
	414
	415	if (chip->can_sleep) {
	416	mutex_lock(&fwd->mlock);
	417	gpio_fwd_set_multiple(fwd, mask, bits);
828546e2	418	mutex_unlock(&fwd->mlock);
01e8d85b AS	419	} else {
	420	spin_lock_irqsave(&fwd->slock, flags);
	421	gpio_fwd_set_multiple(fwd, mask, bits);
828546e2	422	spin_unlock_irqrestore(&fwd->slock, flags);
01e8d85b	423	}
828546e2 GU	424	}
	425
	426	static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset,
	427	unsigned long config)
	428	{
	429	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);
	430
	431	return gpiod_set_config(fwd->descs[offset], config);
	432	}
	433
	434	/**
	435	* gpiochip_fwd_create() - Create a new GPIO forwarder
	436	* @dev: Parent device pointer
	437	* @ngpios: Number of GPIOs in the forwarder.
	438	* @descs: Array containing the GPIO descriptors to forward to.
	439	* This array must contain @ngpios entries, and must not be deallocated
	440	* before the forwarder has been destroyed again.
	441	*
	442	* This function creates a new gpiochip, which forwards all GPIO operations to
	443	* the passed GPIO descriptors.
	444	*
	445	* Return: An opaque object pointer, or an ERR_PTR()-encoded negative error
	446	* code on failure.
	447	*/
	448	static struct gpiochip_fwd gpiochip_fwd_create(struct device dev,
	449	unsigned int ngpios,
	450	struct gpio_desc *descs[])
	451	{
	452	const char *label = dev_name(dev);
	453	struct gpiochip_fwd *fwd;
	454	struct gpio_chip *chip;
	455	unsigned int i;
	456	int error;
	457
	458	fwd = devm_kzalloc(dev, struct_size(fwd, tmp,
	459	BITS_TO_LONGS(ngpios) + ngpios), GFP_KERNEL);
	460	if (!fwd)
	461	return ERR_PTR(-ENOMEM);
	462
	463	chip = &fwd->chip;
	464
	465	/*
	466	* If any of the GPIO lines are sleeping, then the entire forwarder
	467	* will be sleeping.
	468	* If any of the chips support .set_config(), then the forwarder will
	469	* support setting configs.
	470	*/
	471	for (i = 0; i < ngpios; i++) {
	472	struct gpio_chip *parent = gpiod_to_chip(descs[i]);
	473
	474	dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i]));
	475
	476	if (gpiod_cansleep(descs[i]))
	477	chip->can_sleep = true;
	478	if (parent && parent->set_config)
	479	chip->set_config = gpio_fwd_set_config;
	480	}
	481
	482	chip->label = label;
	483	chip->parent = dev;
	484	chip->owner = THIS_MODULE;
	485	chip->get_direction = gpio_fwd_get_direction;
	486	chip->direction_input = gpio_fwd_direction_input;
	487	chip->direction_output = gpio_fwd_direction_output;
488	chip->get = gpio_fwd_get;
01e8d85b	489	chip->get_multiple = gpio_fwd_get_multiple_locked;
828546e2	490	chip->set = gpio_fwd_set;
01e8d85b	491	chip->set_multiple = gpio_fwd_set_multiple_locked;
828546e2 GU	492	chip->base = -1;
	493	chip->ngpio = ngpios;
	494	fwd->descs = descs;
	495
	496	if (chip->can_sleep)
	497	mutex_init(&fwd->mlock);
	498	else
	499	spin_lock_init(&fwd->slock);
	500
	501	error = devm_gpiochip_add_data(dev, chip, fwd);
	502	if (error)
	503	return ERR_PTR(error);
	504
	505	return fwd;
	506	}
	507
	508
	509	/*
	510	* GPIO Aggregator platform device
	511	*/
	512
	513	static int gpio_aggregator_probe(struct platform_device *pdev)
	514	{
	515	struct device *dev = &pdev->dev;
	516	struct gpio_desc **descs;
	517	struct gpiochip_fwd *fwd;
	518	int i, n;
	519
	520	n = gpiod_count(dev, NULL);
	521	if (n < 0)
	522	return n;
	523
	524	descs = devm_kmalloc_array(dev, n, sizeof(*descs), GFP_KERNEL);
	525	if (!descs)
	526	return -ENOMEM;
	527
	528	for (i = 0; i < n; i++) {
	529	descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
	530	if (IS_ERR(descs[i]))
	531	return PTR_ERR(descs[i]);
	532	}
	533
	534	fwd = gpiochip_fwd_create(dev, n, descs);
	535	if (IS_ERR(fwd))
	536	return PTR_ERR(fwd);
	537
	538	platform_set_drvdata(pdev, fwd);
	539	return 0;
	540	}
	541
	542	#ifdef CONFIG_OF
	543	static const struct of_device_id gpio_aggregator_dt_ids[] = {
	544	/*
	545	* Add GPIO-operated devices controlled from userspace below,
	546	* or use "driver_override" in sysfs
	547	*/
	548	{},
	549	};
	550	MODULE_DEVICE_TABLE(of, gpio_aggregator_dt_ids);
	551	#endif
	552
	553	static struct platform_driver gpio_aggregator_driver = {
	554	.probe = gpio_aggregator_probe,
	555	.driver = {
556	.name = DRV_NAME,
557	.groups = gpio_aggregator_groups,
558	.of_match_table = of_match_ptr(gpio_aggregator_dt_ids),
559	},
560	};
561
562	static int __init gpio_aggregator_init(void)
563	{
564	return platform_driver_register(&gpio_aggregator_driver);
565	}
566	module_init(gpio_aggregator_init);
567
568	static void __exit gpio_aggregator_exit(void)
569	{
570	gpio_aggregator_remove_all();
571	platform_driver_unregister(&gpio_aggregator_driver);
572	}
573	module_exit(gpio_aggregator_exit);
574
575	MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
576	MODULE_DESCRIPTION("GPIO Aggregator");
577	MODULE_LICENSE("GPL v2");