#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/pinctrl/consumer.h>
+#include <linux/idr.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <uapi/linux/gpio.h>
#include "gpiolib.h"
#define extra_checks 0
#endif
+/* Device and char device-related information */
+static DEFINE_IDA(gpio_ida);
+static dev_t gpio_devt;
+#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
+static struct bus_type gpio_bus_type = {
+ .name = "gpio",
+};
+
/* gpio_lock prevents conflicts during gpio_desc[] table updates.
* While any GPIO is requested, its gpio_chip is not removable;
* each GPIO's "requested" flag serves as a lock and refcount.
static DEFINE_MUTEX(gpio_lookup_lock);
static LIST_HEAD(gpio_lookup_list);
-LIST_HEAD(gpio_chips);
-
+LIST_HEAD(gpio_devices);
static void gpiochip_free_hogs(struct gpio_chip *chip);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
*/
struct gpio_desc *gpio_to_desc(unsigned gpio)
{
- struct gpio_chip *chip;
+ struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
- list_for_each_entry(chip, &gpio_chips, list) {
- if (chip->base <= gpio && chip->base + chip->ngpio > gpio) {
+ list_for_each_entry(gdev, &gpio_devices, list) {
+ if (gdev->chip->base <= gpio &&
+ gdev->chip->base + gdev->chip->ngpio > gpio) {
spin_unlock_irqrestore(&gpio_lock, flags);
- return &chip->desc[gpio - chip->base];
+ return &gdev->chip->desc[gpio - gdev->chip->base];
}
}
/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
static int gpiochip_find_base(int ngpio)
{
- struct gpio_chip *chip;
+ struct gpio_device *gdev;
int base = ARCH_NR_GPIOS - ngpio;
- list_for_each_entry_reverse(chip, &gpio_chips, list) {
+ list_for_each_entry_reverse(gdev, &gpio_devices, list) {
/* found a free space? */
- if (chip->base + chip->ngpio <= base)
+ if (gdev->chip->base + gdev->chip->ngpio <= base)
break;
else
/* nope, check the space right before the chip */
- base = chip->base - ngpio;
+ base = gdev->chip->base - ngpio;
}
if (gpio_is_valid(base)) {
* Return -EBUSY if the new chip overlaps with some other chip's integer
* space.
*/
-static int gpiochip_add_to_list(struct gpio_chip *chip)
+static int gpiodev_add_to_list(struct gpio_device *gdev)
{
- struct gpio_chip *iterator;
- struct gpio_chip *previous = NULL;
+ struct gpio_device *iterator;
+ struct gpio_device *previous = NULL;
- if (list_empty(&gpio_chips)) {
- list_add_tail(&chip->list, &gpio_chips);
+ if (!gdev->chip)
+ return -EINVAL;
+
+ if (list_empty(&gpio_devices)) {
+ list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
- list_for_each_entry(iterator, &gpio_chips, list) {
- if (iterator->base >= chip->base + chip->ngpio) {
+ list_for_each_entry(iterator, &gpio_devices, list) {
+ /*
+ * The list may contain dangling GPIO devices with no
+ * live chip assigned.
+ */
+ if (!iterator->chip)
+ continue;
+ if (iterator->chip->base >=
+ gdev->chip->base + gdev->chip->ngpio) {
/*
* Iterator is the first GPIO chip so there is no
* previous one
* [base, base + ngpio - 1]) between previous
* and iterator chip.
*/
- if (previous->base + previous->ngpio
- <= chip->base)
+ if (previous->chip->base + previous->chip->ngpio
+ <= gdev->chip->base)
goto found;
}
}
* Let iterator point to the last chip in the list.
*/
- iterator = list_last_entry(&gpio_chips, struct gpio_chip, list);
- if (iterator->base + iterator->ngpio <= chip->base) {
- list_add(&chip->list, &iterator->list);
+ iterator = list_last_entry(&gpio_devices, struct gpio_device, list);
+ if (iterator->chip->base + iterator->chip->ngpio <= gdev->chip->base) {
+ list_add(&gdev->list, &iterator->list);
return 0;
}
- dev_err(chip->parent,
+ dev_err(&gdev->dev,
"GPIO integer space overlap, cannot add chip\n");
return -EBUSY;
found:
- list_add_tail(&chip->list, &iterator->list);
+ list_add_tail(&gdev->list, &iterator->list);
return 0;
}
*/
static struct gpio_desc *gpio_name_to_desc(const char * const name)
{
- struct gpio_chip *chip;
+ struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
- list_for_each_entry(chip, &gpio_chips, list) {
+ list_for_each_entry(gdev, &gpio_devices, list) {
int i;
- for (i = 0; i != chip->ngpio; ++i) {
- struct gpio_desc *gpio = &chip->desc[i];
+ for (i = 0; i != gdev->chip->ngpio; ++i) {
+ struct gpio_desc *gpio = &gdev->chip->desc[i];
if (!gpio->name || !name)
continue;
gpio = gpio_name_to_desc(gc->names[i]);
if (gpio)
- dev_warn(gc->parent, "Detected name collision for "
- "GPIO name '%s'\n",
+ dev_warn(&gc->gpiodev->dev,
+ "Detected name collision for GPIO name '%s'\n",
gc->names[i]);
}
return 0;
}
+/**
+ * gpio_ioctl() - ioctl handler for the GPIO chardev
+ */
+static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct gpio_device *gdev = filp->private_data;
+ struct gpio_chip *chip = gdev->chip;
+ int __user *ip = (int __user *)arg;
+ struct gpiochip_info chipinfo;
+
+ /* We fail any subsequent ioctl():s when the chip is gone */
+ if (!chip)
+ return -ENODEV;
+
+ if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
+ /* Fill in the struct and pass to userspace */
+ strncpy(chipinfo.name, dev_name(&gdev->dev),
+ sizeof(chipinfo.name));
+ chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
+ chipinfo.lines = chip->ngpio;
+ if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
+ return -EFAULT;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+/**
+ * gpio_chrdev_open() - open the chardev for ioctl operations
+ * @inode: inode for this chardev
+ * @filp: file struct for storing private data
+ * Returns 0 on success
+ */
+static int gpio_chrdev_open(struct inode *inode, struct file *filp)
+{
+ struct gpio_device *gdev = container_of(inode->i_cdev,
+ struct gpio_device, chrdev);
+
+ /* Fail on open if the backing gpiochip is gone */
+ if (!gdev || !gdev->chip)
+ return -ENODEV;
+ get_device(&gdev->dev);
+ filp->private_data = gdev;
+ return 0;
+}
+
+/**
+ * gpio_chrdev_release() - close chardev after ioctl operations
+ * @inode: inode for this chardev
+ * @filp: file struct for storing private data
+ * Returns 0 on success
+ */
+static int gpio_chrdev_release(struct inode *inode, struct file *filp)
+{
+ struct gpio_device *gdev = container_of(inode->i_cdev,
+ struct gpio_device, chrdev);
+
+ if (!gdev)
+ return -ENODEV;
+ put_device(&gdev->dev);
+ return 0;
+}
+
+
+static const struct file_operations gpio_fileops = {
+ .release = gpio_chrdev_release,
+ .open = gpio_chrdev_open,
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = gpio_ioctl,
+ .compat_ioctl = gpio_ioctl,
+};
+
+static void gpiodevice_release(struct device *dev)
+{
+ struct gpio_device *gdev = dev_get_drvdata(dev);
+
+ cdev_del(&gdev->chrdev);
+ list_del(&gdev->list);
+ ida_simple_remove(&gpio_ida, gdev->id);
+}
+
/**
* gpiochip_add_data() - register a gpio_chip
* @chip: the chip to register, with chip->base initialized
{
unsigned long flags;
int status = 0;
- unsigned id;
+ unsigned i;
int base = chip->base;
struct gpio_desc *descs;
+ struct gpio_device *gdev;
- descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
- if (!descs)
+ /*
+ * First: allocate and populate the internal stat container, and
+ * set up the struct device.
+ */
+ gdev = kmalloc(sizeof(*gdev), GFP_KERNEL);
+ if (!gdev)
return -ENOMEM;
+ gdev->dev.bus = &gpio_bus_type;
+ gdev->chip = chip;
+ chip->gpiodev = gdev;
+ if (chip->parent) {
+ gdev->dev.parent = chip->parent;
+ gdev->dev.of_node = chip->parent->of_node;
+ } else {
+#ifdef CONFIG_OF_GPIO
+ /* If the gpiochip has an assigned OF node this takes precedence */
+ if (chip->of_node)
+ gdev->dev.of_node = chip->of_node;
+#endif
+ }
+ gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL);
+ if (gdev->id < 0) {
+ status = gdev->id;
+ goto err_free_gdev;
+ }
+ dev_set_name(&gdev->dev, "gpiochip%d", gdev->id);
+ device_initialize(&gdev->dev);
+ dev_set_drvdata(&gdev->dev, gdev);
+ if (chip->parent && chip->parent->driver)
+ gdev->owner = chip->parent->driver->owner;
+ else if (chip->owner)
+ /* TODO: remove chip->owner */
+ gdev->owner = chip->owner;
+ else
+ gdev->owner = THIS_MODULE;
+
+ /* FIXME: devm_kcalloc() these and move to gpio_device */
+ descs = kcalloc(chip->ngpio, sizeof(descs[0]), GFP_KERNEL);
+ if (!descs) {
+ status = -ENOMEM;
+ goto err_free_gdev;
+ }
+ /* FIXME: move driver data into gpio_device dev_set_drvdata() */
chip->data = data;
if (chip->ngpio == 0) {
chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
- return -EINVAL;
+ status = -EINVAL;
+ goto err_free_descs;
}
spin_lock_irqsave(&gpio_lock, flags);
chip->base = base;
}
- status = gpiochip_add_to_list(chip);
+ status = gpiodev_add_to_list(gdev);
if (status) {
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_descs;
}
- for (id = 0; id < chip->ngpio; id++) {
- struct gpio_desc *desc = &descs[id];
+ for (i = 0; i < chip->ngpio; i++) {
+ struct gpio_desc *desc = &descs[i];
+ /* REVISIT: maybe a pointer to gpio_device is better */
desc->chip = chip;
/* REVISIT: most hardware initializes GPIOs as inputs (often
*/
desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
}
-
chip->desc = descs;
spin_unlock_irqrestore(&gpio_lock, flags);
#ifdef CONFIG_PINCTRL
+ /* FIXME: move pin ranges to gpio_device */
INIT_LIST_HEAD(&chip->pin_ranges);
#endif
- if (!chip->owner && chip->parent && chip->parent->driver)
- chip->owner = chip->parent->driver->owner;
-
status = gpiochip_set_desc_names(chip);
if (status)
goto err_remove_from_list;
acpi_gpiochip_add(chip);
+ /*
+ * By first adding the chardev, and then adding the device,
+ * we get a device node entry in sysfs under
+ * /sys/bus/gpio/devices/gpiochipN/dev that can be used for
+ * coldplug of device nodes and other udev business.
+ */
+ cdev_init(&gdev->chrdev, &gpio_fileops);
+ gdev->chrdev.owner = THIS_MODULE;
+ gdev->chrdev.kobj.parent = &gdev->dev.kobj;
+ gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
+ status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
+ if (status < 0)
+ chip_warn(chip, "failed to add char device %d:%d\n",
+ MAJOR(gpio_devt), gdev->id);
+ else
+ chip_dbg(chip, "added GPIO chardev (%d:%d)\n",
+ MAJOR(gpio_devt), gdev->id);
+ status = device_add(&gdev->dev);
+ if (status)
+ goto err_remove_chardev;
+
status = gpiochip_sysfs_register(chip);
if (status)
- goto err_remove_chip;
+ goto err_remove_device;
+ /* From this point, the .release() function cleans up gpio_device */
+ gdev->dev.release = gpiodevice_release;
+ get_device(&gdev->dev);
pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
chip->base, chip->base + chip->ngpio - 1,
chip->label ? : "generic");
return 0;
+err_remove_device:
+ device_del(&gdev->dev);
+err_remove_chardev:
+ cdev_del(&gdev->chrdev);
err_remove_chip:
acpi_gpiochip_remove(chip);
gpiochip_free_hogs(chip);
of_gpiochip_remove(chip);
err_remove_from_list:
spin_lock_irqsave(&gpio_lock, flags);
- list_del(&chip->list);
+ list_del(&gdev->list);
spin_unlock_irqrestore(&gpio_lock, flags);
chip->desc = NULL;
err_free_descs:
kfree(descs);
-
+err_free_gdev:
+ ida_simple_remove(&gpio_ida, gdev->id);
+ kfree(gdev);
/* failures here can mean systems won't boot... */
pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
chip->base, chip->base + chip->ngpio - 1,
*/
void gpiochip_remove(struct gpio_chip *chip)
{
+ struct gpio_device *gdev = chip->gpiodev;
struct gpio_desc *desc;
unsigned long flags;
unsigned id;
bool requested = false;
- gpiochip_sysfs_unregister(chip);
+ /* Numb the device, cancelling all outstanding operations */
+ gdev->chip = NULL;
+ /* FIXME: should the legacy sysfs handling be moved to gpio_device? */
+ gpiochip_sysfs_unregister(chip);
gpiochip_irqchip_remove(chip);
-
acpi_gpiochip_remove(chip);
gpiochip_remove_pin_ranges(chip);
gpiochip_free_hogs(chip);
if (test_bit(FLAG_REQUESTED, &desc->flags))
requested = true;
}
- list_del(&chip->list);
spin_unlock_irqrestore(&gpio_lock, flags);
if (requested)
- dev_crit(chip->parent,
+ dev_crit(&chip->gpiodev->dev,
"REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
+ /* FIXME: need to be moved to gpio_device and held there */
kfree(chip->desc);
chip->desc = NULL;
+
+ /*
+ * The gpiochip side puts its use of the device to rest here:
+ * if there are no userspace clients, the chardev and device will
+ * be removed, else it will be dangling until the last user is
+ * gone.
+ */
+ put_device(&gdev->dev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);
int (*match)(struct gpio_chip *chip,
void *data))
{
+ struct gpio_device *gdev;
struct gpio_chip *chip;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
- list_for_each_entry(chip, &gpio_chips, list)
- if (match(chip, data))
+ list_for_each_entry(gdev, &gpio_devices, list)
+ if (match(gdev->chip, data))
break;
/* No match? */
- if (&chip->list == &gpio_chips)
+ if (&gdev->list == &gpio_devices)
chip = NULL;
+ else
+ chip = gdev->chip;
+
spin_unlock_irqrestore(&gpio_lock, flags);
return chip;
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
- if (!try_module_get(chip->owner))
+ if (!try_module_get(chip->gpiodev->owner))
return -ENODEV;
if (gpiochip_lock_as_irq(chip, d->hwirq)) {
chip_err(chip,
"unable to lock HW IRQ %lu for IRQ\n",
d->hwirq);
- module_put(chip->owner);
+ module_put(chip->gpiodev->owner);
return -EINVAL;
}
return 0;
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
gpiochip_unlock_as_irq(chip, d->hwirq);
- module_put(chip->owner);
+ module_put(chip->gpiodev->owner);
}
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
if (!chip)
goto done;
- if (try_module_get(chip->owner)) {
+ if (try_module_get(chip->gpiodev->owner)) {
status = __gpiod_request(desc, label);
if (status < 0)
- module_put(chip->owner);
+ module_put(chip->gpiodev->owner);
}
done:
void gpiod_free(struct gpio_desc *desc)
{
if (desc && __gpiod_free(desc))
- module_put(desc->chip->owner);
+ module_put(desc->chip->gpiodev->owner);
else
WARN_ON(extra_checks);
}
}
EXPORT_SYMBOL_GPL(gpiod_put_array);
+static int __init gpiolib_dev_init(void)
+{
+ int ret;
+
+ /* Register GPIO sysfs bus */
+ ret = bus_register(&gpio_bus_type);
+ if (ret < 0) {
+ pr_err("gpiolib: could not register GPIO bus type\n");
+ return ret;
+ }
+
+ ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip");
+ if (ret < 0) {
+ pr_err("gpiolib: failed to allocate char dev region\n");
+ bus_unregister(&gpio_bus_type);
+ }
+ return ret;
+}
+core_initcall(gpiolib_dev_init);
+
#ifdef CONFIG_DEBUG_FS
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
{
unsigned long flags;
- struct gpio_chip *chip = NULL;
+ struct gpio_device *gdev = NULL;
loff_t index = *pos;
s->private = "";
spin_lock_irqsave(&gpio_lock, flags);
- list_for_each_entry(chip, &gpio_chips, list)
+ list_for_each_entry(gdev, &gpio_devices, list)
if (index-- == 0) {
spin_unlock_irqrestore(&gpio_lock, flags);
- return chip;
+ return gdev;
}
spin_unlock_irqrestore(&gpio_lock, flags);
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
unsigned long flags;
- struct gpio_chip *chip = v;
+ struct gpio_device *gdev = v;
void *ret = NULL;
spin_lock_irqsave(&gpio_lock, flags);
- if (list_is_last(&chip->list, &gpio_chips))
+ if (list_is_last(&gdev->list, &gpio_devices))
ret = NULL;
else
- ret = list_entry(chip->list.next, struct gpio_chip, list);
+ ret = list_entry(gdev->list.next, struct gpio_device, list);
spin_unlock_irqrestore(&gpio_lock, flags);
s->private = "\n";
static int gpiolib_seq_show(struct seq_file *s, void *v)
{
- struct gpio_chip *chip = v;
- struct device *dev;
+ struct gpio_device *gdev = v;
+ struct gpio_chip *chip = gdev->chip;
+ struct device *parent;
+
+ if (!chip) {
+ seq_printf(s, "%s%s: (dangling chip)", (char *)s->private,
+ dev_name(&gdev->dev));
+ return 0;
+ }
- seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
- chip->base, chip->base + chip->ngpio - 1);
- dev = chip->parent;
- if (dev)
- seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
- dev_name(dev));
+ seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private,
+ dev_name(&gdev->dev),
+ chip->base, chip->base + chip->ngpio - 1);
+ parent = chip->parent;
+ if (parent)
+ seq_printf(s, ", parent: %s/%s",
+ parent->bus ? parent->bus->name : "no-bus",
+ dev_name(parent));
if (chip->label)
seq_printf(s, ", %s", chip->label);
if (chip->can_sleep)
projects / deliverable / linux.git / commitdiff
