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gpio-virtuser.c
1809 lines (1440 loc) · 44.2 KB
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gpio-virtuser.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Configurable virtual GPIO consumer module.
*
* Copyright (C) 2023-2024 Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/atomic.h>
#include <linux/bitmap.h>
#include <linux/cleanup.h>
#include <linux/completion.h>
#include <linux/configfs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/irq_work.h>
#include <linux/kernel.h>
#include <linux/limits.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/of.h>
#include <linux/overflow.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/string_helpers.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#define GPIO_CONSUMER_NAME_MAX_LEN 32
static DEFINE_IDA(gpio_virtuser_ida);
enum gpio_virtuser_line_array_attr_id {
GPIO_CONSUMER_LINE_ARRAY_ATTR_VALUES,
GPIO_CONSUMER_LINE_ARRAY_ATTR_VALUES_ATOMIC,
GPIO_CONSUMER_LINE_ARRAY_ATTR_COUNT,
};
enum gpio_virtuser_line_attr_id {
GPIO_CONSUMER_LINE_ATTR_DIRECTION,
GPIO_CONSUMER_LINE_ATTR_DIRECTION_ATOMIC,
GPIO_CONSUMER_LINE_ATTR_VALUE,
GPIO_CONSUMER_LINE_ATTR_VALUE_ATOMIC,
GPIO_CONSUMER_LINE_ATTR_DEBOUNCE,
GPIO_CONSUMER_LINE_ATTR_CONSUMER,
GPIO_CONSUMER_LINE_ATTR_INTERRUPTS,
GPIO_CONSUMER_LINE_ATTR_COUNT,
};
struct gpio_virtuser_line_array_data {
struct gpio_descs *descs;
struct kobject *kobj;
struct attribute_group *attr_group;
};
struct gpio_virtuser_line_data {
struct gpio_desc *desc;
struct kobject *kobj;
struct attribute_group *attr_group;
char consumer[GPIO_CONSUMER_NAME_MAX_LEN];
struct mutex consumer_lock;
unsigned int debounce;
atomic_t irq;
atomic_t irq_count;
};
struct gpio_virtuser_attr_ctx {
struct device_attribute dev_attr;
void *data;
};
static struct gpio_virtuser_attr_ctx *
to_gpio_virtuser_attr_ctx(struct device_attribute *attr)
{
return container_of(attr, struct gpio_virtuser_attr_ctx, dev_attr);
}
static void *to_gpio_virtuser_data(struct device_attribute *attr)
{
struct gpio_virtuser_attr_ctx *ctx = to_gpio_virtuser_attr_ctx(attr);
return ctx->data;
}
struct gpio_virtuser_attr_descr {
const char *name;
ssize_t (*show)(struct device *, struct device_attribute *, char *);
ssize_t (*store)(struct device *, struct device_attribute *,
const char *, size_t);
};
struct gpio_virtuser_irq_work_context {
struct irq_work work;
struct completion work_completion;
/* For single line operations: */
struct gpio_desc *desc;
int dir;
int val;
int ret;
/* For desc array operations: */
struct gpio_descs *descs;
unsigned long *values;
};
static struct gpio_virtuser_irq_work_context *
to_gpio_virtuser_irq_work_context(struct irq_work *work)
{
return container_of(work, struct gpio_virtuser_irq_work_context, work);
}
static void
gpio_virtuser_init_irq_work_context(struct gpio_virtuser_irq_work_context *ctx)
{
memset(ctx, 0, sizeof(*ctx));
init_completion(&ctx->work_completion);
}
static void
gpio_virtuser_irq_work_queue_sync(struct gpio_virtuser_irq_work_context *ctx)
{
irq_work_queue(&ctx->work);
wait_for_completion(&ctx->work_completion);
}
static ssize_t gpio_virtuser_sysfs_emit_value_array(char *buf,
unsigned long *values,
size_t num_values)
{
ssize_t len = 0;
size_t i;
for (i = 0; i < num_values; i++)
len += sysfs_emit_at(buf, len, "%d",
test_bit(i, values) ? 1 : 0);
return len + sysfs_emit_at(buf, len, "\n");
}
static int gpio_virtuser_sysfs_parse_value_array(const char *buf, size_t len,
unsigned long *values)
{
size_t i;
for (i = 0; i < len; i++) {
if (buf[i] == '0')
clear_bit(i, values);
else if (buf[i] == '1')
set_bit(i, values);
else
return -EINVAL;
}
return 0;
}
static ssize_t
gpio_virtuser_sysfs_value_array_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_array_data *data = to_gpio_virtuser_data(attr);
struct gpio_descs *descs = data->descs;
int ret;
unsigned long *values __free(bitmap) = bitmap_zalloc(descs->ndescs,
GFP_KERNEL);
if (!values)
return -ENOMEM;
ret = gpiod_get_array_value_cansleep(descs->ndescs, descs->desc,
descs->info, values);
if (ret)
return ret;
return gpio_virtuser_sysfs_emit_value_array(buf, values, descs->ndescs);
}
static ssize_t
gpio_virtuser_sysfs_value_array_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_array_data *data = to_gpio_virtuser_data(attr);
struct gpio_descs *descs = data->descs;
int ret;
if (len - 1 != descs->ndescs)
return -EINVAL;
unsigned long *values __free(bitmap) = bitmap_alloc(descs->ndescs,
GFP_KERNEL);
if (!values)
return -ENOMEM;
ret = gpio_virtuser_sysfs_parse_value_array(buf, descs->ndescs, values);
if (ret)
return ret;
ret = gpiod_set_array_value_cansleep(descs->ndescs, descs->desc,
descs->info, values);
if (ret)
return ret;
return len;
}
static void gpio_virtuser_get_value_array_atomic(struct irq_work *work)
{
struct gpio_virtuser_irq_work_context *ctx =
to_gpio_virtuser_irq_work_context(work);
struct gpio_descs *descs = ctx->descs;
ctx->ret = gpiod_get_array_value(descs->ndescs, descs->desc,
descs->info, ctx->values);
complete(&ctx->work_completion);
}
static ssize_t
gpio_virtuser_sysfs_value_array_atomic_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct gpio_virtuser_line_array_data *data = to_gpio_virtuser_data(attr);
struct gpio_virtuser_irq_work_context ctx;
struct gpio_descs *descs = data->descs;
unsigned long *values __free(bitmap) = bitmap_zalloc(descs->ndescs,
GFP_KERNEL);
if (!values)
return -ENOMEM;
gpio_virtuser_init_irq_work_context(&ctx);
ctx.work = IRQ_WORK_INIT_HARD(gpio_virtuser_get_value_array_atomic);
ctx.descs = data->descs;
ctx.values = values;
gpio_virtuser_irq_work_queue_sync(&ctx);
if (ctx.ret)
return ctx.ret;
return gpio_virtuser_sysfs_emit_value_array(buf, values, descs->ndescs);
}
static void gpio_virtuser_set_value_array_atomic(struct irq_work *work)
{
struct gpio_virtuser_irq_work_context *ctx =
to_gpio_virtuser_irq_work_context(work);
struct gpio_descs *descs = ctx->descs;
ctx->ret = gpiod_set_array_value(descs->ndescs, descs->desc,
descs->info, ctx->values);
complete(&ctx->work_completion);
}
static ssize_t
gpio_virtuser_sysfs_value_array_atomic_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_array_data *data = to_gpio_virtuser_data(attr);
struct gpio_virtuser_irq_work_context ctx;
struct gpio_descs *descs = data->descs;
int ret;
unsigned long *values __free(bitmap) = bitmap_zalloc(descs->ndescs,
GFP_KERNEL);
if (!values)
return -ENOMEM;
ret = gpio_virtuser_sysfs_parse_value_array(buf, descs->ndescs, values);
if (ret)
return ret;
gpio_virtuser_init_irq_work_context(&ctx);
ctx.work = IRQ_WORK_INIT_HARD(gpio_virtuser_set_value_array_atomic);
ctx.descs = data->descs;
ctx.values = values;
gpio_virtuser_irq_work_queue_sync(&ctx);
if (ctx.ret)
return ctx.ret;
return len;
}
static ssize_t gpio_virtuser_emit_direction(char *buf, int dir)
{
return sysfs_emit(buf, "%s\n",
dir == GPIO_LINE_DIRECTION_IN ? "input" : "output");
}
static int gpio_virtuser_set_direction(struct gpio_desc *desc, int dir, int val)
{
if (dir == GPIO_LINE_DIRECTION_IN)
return gpiod_direction_input(desc);
return gpiod_direction_output(desc, val);
}
static int gpio_virtuser_parse_direction(const char *buf, int *dir, int *val)
{
if (sysfs_streq(buf, "input")) {
*dir = GPIO_LINE_DIRECTION_IN;
return 0;
}
if (sysfs_streq(buf, "output-high"))
*val = 1;
else if (sysfs_streq(buf, "output-low"))
*val = 0;
else
return -EINVAL;
*dir = GPIO_LINE_DIRECTION_OUT;
return 0;
}
static ssize_t
gpio_virtuser_sysfs_direction_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
int dir;
dir = gpiod_get_direction(data->desc);
if (dir < 0)
return dir;
return gpio_virtuser_emit_direction(buf, dir);
}
static ssize_t
gpio_virtuser_sysfs_direction_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
int ret, dir, val;
ret = gpio_virtuser_parse_direction(buf, &dir, &val);
if (ret)
return ret;
ret = gpio_virtuser_set_direction(data->desc, dir, val);
if (ret)
return ret;
return len;
}
static void gpio_virtuser_get_direction_atomic(struct irq_work *work)
{
struct gpio_virtuser_irq_work_context *ctx =
to_gpio_virtuser_irq_work_context(work);
ctx->dir = gpiod_get_direction(ctx->desc);
complete(&ctx->work_completion);
}
static ssize_t
gpio_virtuser_sysfs_direction_atomic_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
struct gpio_virtuser_irq_work_context ctx;
gpio_virtuser_init_irq_work_context(&ctx);
ctx.work = IRQ_WORK_INIT_HARD(gpio_virtuser_get_direction_atomic);
ctx.desc = data->desc;
gpio_virtuser_irq_work_queue_sync(&ctx);
return gpio_virtuser_emit_direction(buf, ctx.dir);
}
static void gpio_virtuser_set_direction_atomic(struct irq_work *work)
{
struct gpio_virtuser_irq_work_context *ctx =
to_gpio_virtuser_irq_work_context(work);
ctx->ret = gpio_virtuser_set_direction(ctx->desc, ctx->dir, ctx->val);
complete(&ctx->work_completion);
}
static ssize_t
gpio_virtuser_sysfs_direction_atomic_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
struct gpio_virtuser_irq_work_context ctx;
int ret, dir, val;
ret = gpio_virtuser_parse_direction(buf, &dir, &val);
if (ret)
return ret;
gpio_virtuser_init_irq_work_context(&ctx);
ctx.work = IRQ_WORK_INIT_HARD(gpio_virtuser_set_direction_atomic);
ctx.desc = data->desc;
ctx.dir = dir;
ctx.val = val;
gpio_virtuser_irq_work_queue_sync(&ctx);
return len;
}
static const char *const gpio_virtuser_sysfs_value_strings[] = {
[0] = "inactive",
[1] = "active",
};
static ssize_t gpio_virtuser_emit_value(char *buf, int value)
{
return sysfs_emit(buf, "%s\n",
gpio_virtuser_sysfs_value_strings[value]);
}
static int gpio_virtuser_parse_value(const char *buf)
{
int value, ret;
value = sysfs_match_string(gpio_virtuser_sysfs_value_strings, buf);
if (value < 0) {
/* Can be 0 or 1 too. */
ret = kstrtoint(buf, 0, &value);
if (ret)
return ret;
if (value != 0 && value != 1)
return -EINVAL;
}
return value;
}
static ssize_t
gpio_virtuser_sysfs_value_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
int value;
value = gpiod_get_value_cansleep(data->desc);
if (value < 0)
return value;
return gpio_virtuser_emit_value(buf, value);
}
static ssize_t
gpio_virtuser_sysfs_value_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
int value;
value = gpio_virtuser_parse_value(buf);
if (value < 0)
return value;
gpiod_set_value_cansleep(data->desc, value);
return len;
}
static void gpio_virtuser_get_value_atomic(struct irq_work *work)
{
struct gpio_virtuser_irq_work_context *ctx =
to_gpio_virtuser_irq_work_context(work);
ctx->val = gpiod_get_value(ctx->desc);
complete(&ctx->work_completion);
}
static ssize_t
gpio_virtuser_sysfs_value_atomic_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
struct gpio_virtuser_irq_work_context ctx;
gpio_virtuser_init_irq_work_context(&ctx);
ctx.work = IRQ_WORK_INIT_HARD(gpio_virtuser_get_value_atomic);
ctx.desc = data->desc;
gpio_virtuser_irq_work_queue_sync(&ctx);
return gpio_virtuser_emit_value(buf, ctx.val);
}
static void gpio_virtuser_set_value_atomic(struct irq_work *work)
{
struct gpio_virtuser_irq_work_context *ctx =
to_gpio_virtuser_irq_work_context(work);
gpiod_set_value(ctx->desc, ctx->val);
complete(&ctx->work_completion);
}
static ssize_t
gpio_virtuser_sysfs_value_atomic_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
struct gpio_virtuser_irq_work_context ctx;
int val;
val = gpio_virtuser_parse_value(buf);
if (val < 0)
return val;
gpio_virtuser_init_irq_work_context(&ctx);
ctx.work = IRQ_WORK_INIT_HARD(gpio_virtuser_set_value_atomic);
ctx.desc = data->desc;
ctx.val = val;
gpio_virtuser_irq_work_queue_sync(&ctx);
return len;
}
static ssize_t
gpio_virtuser_sysfs_debounce_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
return sysfs_emit(buf, "%u\n", READ_ONCE(data->debounce));
}
static ssize_t
gpio_virtuser_sysfs_debounce_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
unsigned int debounce;
int ret;
ret = kstrtouint(buf, 10, &debounce);
if (ret)
return ret;
ret = gpiod_set_debounce(data->desc, debounce);
if (ret)
return ret;
WRITE_ONCE(data->debounce, debounce);
return len;
}
static ssize_t
gpio_virtuser_sysfs_consumer_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
guard(mutex)(&data->consumer_lock);
return sysfs_emit(buf, "%s\n", data->consumer);
}
static ssize_t
gpio_virtuser_sysfs_consumer_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
int ret;
if (strlen(buf) > GPIO_CONSUMER_NAME_MAX_LEN)
return -EINVAL;
guard(mutex)(&data->consumer_lock);
ret = gpiod_set_consumer_name(data->desc, buf);
if (ret)
return ret;
sprintf(data->consumer, buf);
return len;
}
static ssize_t
gpio_virtuser_sysfs_interrupts_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
return sysfs_emit(buf, "%u\n", atomic_read(&data->irq_count));
}
static irqreturn_t gpio_virtuser_irq_handler(int irq, void *data)
{
struct gpio_virtuser_line_data *line = data;
atomic_inc(&line->irq_count);
return IRQ_HANDLED;
}
static ssize_t
gpio_virtuser_sysfs_interrupts_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct gpio_virtuser_line_data *data = to_gpio_virtuser_data(attr);
int ret, irq;
bool enable;
ret = kstrtobool(buf, &enable);
if (ret)
return ret;
if (enable) {
irq = gpiod_to_irq(data->desc);
if (irq < 0)
return irq;
ret = request_threaded_irq(irq, NULL,
gpio_virtuser_irq_handler,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING |
IRQF_ONESHOT,
data->consumer, data);
if (ret)
return ret;
atomic_set(&data->irq, irq);
} else {
irq = atomic_xchg(&data->irq, 0);
free_irq(irq, data);
}
return len;
}
static const struct gpio_virtuser_attr_descr gpio_virtuser_line_array_attrs[] = {
[GPIO_CONSUMER_LINE_ARRAY_ATTR_VALUES] = {
.name = "values",
.show = gpio_virtuser_sysfs_value_array_show,
.store = gpio_virtuser_sysfs_value_array_store,
},
[GPIO_CONSUMER_LINE_ARRAY_ATTR_VALUES_ATOMIC] = {
.name = "values_atomic",
.show = gpio_virtuser_sysfs_value_array_atomic_show,
.store = gpio_virtuser_sysfs_value_array_atomic_store,
},
};
static const struct gpio_virtuser_attr_descr gpio_virtuser_line_attrs[] = {
[GPIO_CONSUMER_LINE_ATTR_DIRECTION] = {
.name = "direction",
.show = gpio_virtuser_sysfs_direction_show,
.store = gpio_virtuser_sysfs_direction_store,
},
[GPIO_CONSUMER_LINE_ATTR_DIRECTION_ATOMIC] = {
.name = "direction_atomic",
.show = gpio_virtuser_sysfs_direction_atomic_show,
.store = gpio_virtuser_sysfs_direction_atomic_store,
},
[GPIO_CONSUMER_LINE_ATTR_VALUE] = {
.name = "value",
.show = gpio_virtuser_sysfs_value_show,
.store = gpio_virtuser_sysfs_value_store,
},
[GPIO_CONSUMER_LINE_ATTR_VALUE_ATOMIC] = {
.name = "value_atomic",
.show = gpio_virtuser_sysfs_value_atomic_show,
.store = gpio_virtuser_sysfs_value_atomic_store,
},
[GPIO_CONSUMER_LINE_ATTR_DEBOUNCE] = {
.name = "debounce",
.show = gpio_virtuser_sysfs_debounce_show,
.store = gpio_virtuser_sysfs_debounce_store,
},
[GPIO_CONSUMER_LINE_ATTR_CONSUMER] = {
.name = "consumer",
.show = gpio_virtuser_sysfs_consumer_show,
.store = gpio_virtuser_sysfs_consumer_store,
},
[GPIO_CONSUMER_LINE_ATTR_INTERRUPTS] = {
.name = "interrupts",
.show = gpio_virtuser_sysfs_interrupts_show,
.store = gpio_virtuser_sysfs_interrupts_store,
},
};
static void gpio_virtuser_line_array_attr_remove(void *data)
{
struct gpio_virtuser_line_array_data *lines = data;
sysfs_remove_group(lines->kobj, lines->attr_group);
}
static void gpio_virtuser_line_attr_remove(void *data)
{
struct gpio_virtuser_line_data *line = data;
sysfs_remove_group(line->kobj, line->attr_group);
}
static struct attribute *
gpio_virtuser_make_attribute(struct device *dev, void *data,
const struct gpio_virtuser_attr_descr *descr)
{
struct gpio_virtuser_attr_ctx *ctx;
ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
ctx->data = data;
sysfs_attr_init(&ctx->dev_attr.attr);
ctx->dev_attr.attr.name = descr->name;
ctx->dev_attr.attr.mode = 0644;
ctx->dev_attr.show = descr->show;
ctx->dev_attr.store = descr->store;
return &ctx->dev_attr.attr;
}
static int gpio_virtuser_sysfs_init_line_array_attrs(struct device *dev,
struct gpio_descs *descs,
const char *id)
{
struct gpio_virtuser_line_array_data *data;
struct attribute **attrs;
unsigned int i;
int ret;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->kobj = &dev->kobj;
data->descs = descs;
data->attr_group = devm_kzalloc(dev, sizeof(*data->attr_group),
GFP_KERNEL);
if (!data->attr_group)
return -ENOMEM;
data->attr_group->name = devm_kasprintf(dev, GFP_KERNEL,
"gpiod:%s", id);
if (!data->attr_group->name)
return -ENOMEM;
attrs = devm_kcalloc(dev, GPIO_CONSUMER_LINE_ARRAY_ATTR_COUNT + 1,
sizeof(*attrs), GFP_KERNEL);
if (!attrs)
return -ENOMEM;
for (i = 0; i < GPIO_CONSUMER_LINE_ARRAY_ATTR_COUNT; i++) {
attrs[i] = gpio_virtuser_make_attribute(dev, data,
&gpio_virtuser_line_array_attrs[i]);
if (IS_ERR(attrs[i]))
return PTR_ERR(attrs[i]);
}
data->attr_group->attrs = attrs;
ret = sysfs_create_group(&dev->kobj, data->attr_group);
if (ret)
return ret;
return devm_add_action_or_reset(dev,
gpio_virtuser_line_array_attr_remove,
data);
}
static void gpio_virtuser_mutex_destroy(void *data)
{
struct mutex *lock = data;
mutex_destroy(lock);
}
static int gpio_virtuser_sysfs_init_line_attrs(struct device *dev,
struct gpio_desc *desc,
const char *id,
unsigned int index)
{
struct gpio_virtuser_line_data *data;
struct attribute **attrs;
unsigned int i;
int ret;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->kobj = &dev->kobj;
data->desc = desc;
sprintf(data->consumer, id);
atomic_set(&data->irq, 0);
atomic_set(&data->irq_count, 0);
mutex_init(&data->consumer_lock);
ret = devm_add_action_or_reset(dev, gpio_virtuser_mutex_destroy,
&data->consumer_lock);
if (ret)
return ret;
data->attr_group = devm_kzalloc(dev, sizeof(*data->attr_group),
GFP_KERNEL);
if (!data->attr_group)
return -ENOMEM;
data->attr_group->name = devm_kasprintf(dev, GFP_KERNEL, "gpiod:%s:%u",
id, index);
if (!data->attr_group->name)
return -ENOMEM;
attrs = devm_kcalloc(dev, GPIO_CONSUMER_LINE_ATTR_COUNT + 1,
sizeof(*attrs), GFP_KERNEL);
if (!attrs)
return -ENOMEM;
for (i = 0; i < GPIO_CONSUMER_LINE_ATTR_COUNT; i++) {
attrs[i] = gpio_virtuser_make_attribute(dev, data,
&gpio_virtuser_line_attrs[i]);
if (IS_ERR(attrs[i]))
return PTR_ERR(attrs[i]);
}
data->attr_group->attrs = attrs;
ret = sysfs_create_group(&dev->kobj, data->attr_group);
if (ret)
return ret;
return devm_add_action_or_reset(dev, gpio_virtuser_line_attr_remove,
data);
}
static int gpio_virtuser_prop_is_gpio(struct property *prop)
{
char *dash = strpbrk(prop->name, "-");
return dash && strcmp(dash, "-gpios") == 0;
}
/*
* If this is an OF-based system, then we iterate over properties and consider
* all whose names end in "-gpios". For configfs we expect an additional string
* array property - "gpio-virtuser,ids" - containing the list of all GPIO IDs
* to request.
*/
static int gpio_virtuser_count_ids(struct device *dev)
{
struct fwnode_handle *fwnode = dev_fwnode(dev);
struct property *prop;
int ret = 0;
if (is_of_node(fwnode)) {
for_each_property_of_node(to_of_node(fwnode), prop) {
if (gpio_virtuser_prop_is_gpio(prop))
++ret;
}
return ret;
}
return device_property_string_array_count(dev, "gpio-virtuser,ids");
}
static int gpio_virtuser_get_ids(struct device *dev, const char **ids,
int num_ids)
{
struct fwnode_handle *fwnode = dev_fwnode(dev);
struct property *prop;
size_t pos = 0, diff;
char *dash, *tmp;
if (is_of_node(fwnode)) {
for_each_property_of_node(to_of_node(fwnode), prop) {
if (!gpio_virtuser_prop_is_gpio(prop))
continue;
dash = strpbrk(prop->name, "-");
diff = dash - prop->name;
tmp = devm_kmemdup(dev, prop->name, diff + 1,
GFP_KERNEL);
if (!tmp)
return -ENOMEM;
tmp[diff] = '\0';
ids[pos++] = tmp;
}
return 0;
}
return device_property_read_string_array(dev, "gpio-virtuser,ids",
ids, num_ids);
}
static int gpio_virtuser_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct gpio_descs *descs;
int ret, num_ids = 0, i;
const char **ids;
unsigned int j;
num_ids = gpio_virtuser_count_ids(dev);
if (num_ids < 0)
return dev_err_probe(dev, num_ids,
"Failed to get the number of GPIOs to request\n");
if (num_ids == 0) {
dev_err(dev, "No GPIO IDs specified\n");
return -EINVAL;
}
ids = devm_kcalloc(dev, num_ids, sizeof(*ids), GFP_KERNEL);
if (!ids)
return -ENOMEM;
ret = gpio_virtuser_get_ids(dev, ids, num_ids);
if (ret < 0)
return dev_err_probe(dev, ret,
"Failed to get the IDs of GPIOs to request\n");
for (i = 0; i < num_ids; i++) {
descs = devm_gpiod_get_array(dev, ids[i], GPIOD_ASIS);
if (IS_ERR(descs))
return dev_err_probe(dev, PTR_ERR(descs),
"Failed to request the '%s' GPIOs\n",
ids[i]);
ret = gpio_virtuser_sysfs_init_line_array_attrs(dev, descs,
ids[i]);
if (ret)
return dev_err_probe(dev, ret,
"Failed to setup the sysfs array interface for the '%s' GPIOs\n",
ids[i]);
for (j = 0; j < descs->ndescs; j++) {
ret = gpio_virtuser_sysfs_init_line_attrs(dev,
descs->desc[j],
ids[i], j);
if (ret)
return dev_err_probe(dev, ret,
"Failed to setup the sysfs line interface for the '%s' GPIOs\n",
ids[i]);
}
}
return 0;
}
static const struct of_device_id gpio_virtuser_of_match[] = {
{ .compatible = "gpio-virtuser" },
{ }
};
MODULE_DEVICE_TABLE(of, gpio_virtuser_of_match);
static struct platform_driver gpio_virtuser_driver = {
.driver = {
.name = "gpio-virtuser",
.of_match_table = gpio_virtuser_of_match,
},
.probe = gpio_virtuser_probe,
};
struct gpio_virtuser_device {
struct config_group group;
struct platform_device *pdev;
int id;
struct mutex lock;
struct notifier_block bus_notifier;
struct completion probe_completion;
bool driver_bound;