blob: eb80dac4e26a52e6f18a4652d3c7fb03451b516a [file] [log] [blame]
#include <linux/bitmap.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/pinctrl/consumer.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/compat.h>
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/kfifo.h>
#include <linux/poll.h>
#include <linux/timekeeping.h>
#include <uapi/linux/gpio.h>
#include "gpiolib.h"
#define CREATE_TRACE_POINTS
#include <trace/events/gpio.h>
/* Implementation infrastructure for GPIO interfaces.
*
* The GPIO programming interface allows for inlining speed-critical
* get/set operations for common cases, so that access to SOC-integrated
* GPIOs can sometimes cost only an instruction or two per bit.
*/
/* When debugging, extend minimal trust to callers and platform code.
* Also emit diagnostic messages that may help initial bringup, when
* board setup or driver bugs are most common.
*
* Otherwise, minimize overhead in what may be bitbanging codepaths.
*/
#ifdef DEBUG
#define extra_checks 1
#else
#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.
*/
DEFINE_SPINLOCK(gpio_lock);
static DEFINE_MUTEX(gpio_lookup_lock);
static LIST_HEAD(gpio_lookup_list);
LIST_HEAD(gpio_devices);
static void gpiochip_free_hogs(struct gpio_chip *chip);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
static bool gpiolib_initialized;
static inline void desc_set_label(struct gpio_desc *d, const char *label)
{
d->label = label;
}
/**
* gpio_to_desc - Convert a GPIO number to its descriptor
* @gpio: global GPIO number
*
* Returns:
* The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
* with the given number exists in the system.
*/
struct gpio_desc *gpio_to_desc(unsigned gpio)
{
struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
if (gdev->base <= gpio &&
gdev->base + gdev->ngpio > gpio) {
spin_unlock_irqrestore(&gpio_lock, flags);
return &gdev->descs[gpio - gdev->base];
}
}
spin_unlock_irqrestore(&gpio_lock, flags);
if (!gpio_is_valid(gpio))
WARN(1, "invalid GPIO %d\n", gpio);
return NULL;
}
EXPORT_SYMBOL_GPL(gpio_to_desc);
/**
* gpiochip_get_desc - get the GPIO descriptor corresponding to the given
* hardware number for this chip
* @chip: GPIO chip
* @hwnum: hardware number of the GPIO for this chip
*
* Returns:
* A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
* in the given chip for the specified hardware number.
*/
struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
u16 hwnum)
{
struct gpio_device *gdev = chip->gpiodev;
if (hwnum >= gdev->ngpio)
return ERR_PTR(-EINVAL);
return &gdev->descs[hwnum];
}
/**
* desc_to_gpio - convert a GPIO descriptor to the integer namespace
* @desc: GPIO descriptor
*
* This should disappear in the future but is needed since we still
* use GPIO numbers for error messages and sysfs nodes.
*
* Returns:
* The global GPIO number for the GPIO specified by its descriptor.
*/
int desc_to_gpio(const struct gpio_desc *desc)
{
return desc->gdev->base + (desc - &desc->gdev->descs[0]);
}
EXPORT_SYMBOL_GPL(desc_to_gpio);
/**
* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
* @desc: descriptor to return the chip of
*/
struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
if (!desc || !desc->gdev || !desc->gdev->chip)
return NULL;
return desc->gdev->chip;
}
EXPORT_SYMBOL_GPL(gpiod_to_chip);
/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
static int gpiochip_find_base(int ngpio)
{
struct gpio_device *gdev;
int base = ARCH_NR_GPIOS - ngpio;
list_for_each_entry_reverse(gdev, &gpio_devices, list) {
/* found a free space? */
if (gdev->base + gdev->ngpio <= base)
break;
else
/* nope, check the space right before the chip */
base = gdev->base - ngpio;
}
if (gpio_is_valid(base)) {
pr_debug("%s: found new base at %d\n", __func__, base);
return base;
} else {
pr_err("%s: cannot find free range\n", __func__);
return -ENOSPC;
}
}
/**
* gpiod_get_direction - return the current direction of a GPIO
* @desc: GPIO to get the direction of
*
* Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
*
* This function may sleep if gpiod_cansleep() is true.
*/
int gpiod_get_direction(struct gpio_desc *desc)
{
struct gpio_chip *chip;
unsigned offset;
int status = -EINVAL;
chip = gpiod_to_chip(desc);
offset = gpio_chip_hwgpio(desc);
if (!chip->get_direction)
return status;
status = chip->get_direction(chip, offset);
if (status > 0) {
/* GPIOF_DIR_IN, or other positive */
status = 1;
clear_bit(FLAG_IS_OUT, &desc->flags);
}
if (status == 0) {
/* GPIOF_DIR_OUT */
set_bit(FLAG_IS_OUT, &desc->flags);
}
return status;
}
EXPORT_SYMBOL_GPL(gpiod_get_direction);
/*
* Add a new chip to the global chips list, keeping the list of chips sorted
* by range(means [base, base + ngpio - 1]) order.
*
* Return -EBUSY if the new chip overlaps with some other chip's integer
* space.
*/
static int gpiodev_add_to_list(struct gpio_device *gdev)
{
struct gpio_device *prev, *next;
if (list_empty(&gpio_devices)) {
/* initial entry in list */
list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
next = list_entry(gpio_devices.next, struct gpio_device, list);
if (gdev->base + gdev->ngpio <= next->base) {
/* add before first entry */
list_add(&gdev->list, &gpio_devices);
return 0;
}
prev = list_entry(gpio_devices.prev, struct gpio_device, list);
if (prev->base + prev->ngpio <= gdev->base) {
/* add behind last entry */
list_add_tail(&gdev->list, &gpio_devices);
return 0;
}
list_for_each_entry_safe(prev, next, &gpio_devices, list) {
/* at the end of the list */
if (&next->list == &gpio_devices)
break;
/* add between prev and next */
if (prev->base + prev->ngpio <= gdev->base
&& gdev->base + gdev->ngpio <= next->base) {
list_add(&gdev->list, &prev->list);
return 0;
}
}
dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n");
return -EBUSY;
}
/*
* Convert a GPIO name to its descriptor
*/
static struct gpio_desc *gpio_name_to_desc(const char * const name)
{
struct gpio_device *gdev;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
int i;
for (i = 0; i != gdev->ngpio; ++i) {
struct gpio_desc *desc = &gdev->descs[i];
if (!desc->name || !name)
continue;
if (!strcmp(desc->name, name)) {
spin_unlock_irqrestore(&gpio_lock, flags);
return desc;
}
}
}
spin_unlock_irqrestore(&gpio_lock, flags);
return NULL;
}
/*
* Takes the names from gc->names and checks if they are all unique. If they
* are, they are assigned to their gpio descriptors.
*
* Warning if one of the names is already used for a different GPIO.
*/
static int gpiochip_set_desc_names(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
int i;
if (!gc->names)
return 0;
/* First check all names if they are unique */
for (i = 0; i != gc->ngpio; ++i) {
struct gpio_desc *gpio;
gpio = gpio_name_to_desc(gc->names[i]);
if (gpio)
dev_warn(&gdev->dev,
"Detected name collision for GPIO name '%s'\n",
gc->names[i]);
}
/* Then add all names to the GPIO descriptors */
for (i = 0; i != gc->ngpio; ++i)
gdev->descs[i].name = gc->names[i];
return 0;
}
/*
* GPIO line handle management
*/
/**
* struct linehandle_state - contains the state of a userspace handle
* @gdev: the GPIO device the handle pertains to
* @label: consumer label used to tag descriptors
* @descs: the GPIO descriptors held by this handle
* @numdescs: the number of descriptors held in the descs array
*/
struct linehandle_state {
struct gpio_device *gdev;
const char *label;
struct gpio_desc *descs[GPIOHANDLES_MAX];
u32 numdescs;
};
#define GPIOHANDLE_REQUEST_VALID_FLAGS \
(GPIOHANDLE_REQUEST_INPUT | \
GPIOHANDLE_REQUEST_OUTPUT | \
GPIOHANDLE_REQUEST_ACTIVE_LOW | \
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
static long linehandle_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct linehandle_state *lh = filep->private_data;
void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd;
int i;
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
int val;
memset(&ghd, 0, sizeof(ghd));
/* TODO: check if descriptors are really input */
for (i = 0; i < lh->numdescs; i++) {
val = gpiod_get_value_cansleep(lh->descs[i]);
if (val < 0)
return val;
ghd.values[i] = val;
}
if (copy_to_user(ip, &ghd, sizeof(ghd)))
return -EFAULT;
return 0;
} else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) {
int vals[GPIOHANDLES_MAX];
/* TODO: check if descriptors are really output */
if (copy_from_user(&ghd, ip, sizeof(ghd)))
return -EFAULT;
/* Clamp all values to [0,1] */
for (i = 0; i < lh->numdescs; i++)
vals[i] = !!ghd.values[i];
/* Reuse the array setting function */
gpiod_set_array_value_complex(false,
true,
lh->numdescs,
lh->descs,
vals);
return 0;
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static int linehandle_release(struct inode *inode, struct file *filep)
{
struct linehandle_state *lh = filep->private_data;
struct gpio_device *gdev = lh->gdev;
int i;
for (i = 0; i < lh->numdescs; i++)
gpiod_free(lh->descs[i]);
kfree(lh->label);
kfree(lh);
put_device(&gdev->dev);
return 0;
}
static const struct file_operations linehandle_fileops = {
.release = linehandle_release,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = linehandle_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = linehandle_ioctl_compat,
#endif
};
static int linehandle_create(struct gpio_device *gdev, void __user *ip)
{
struct gpiohandle_request handlereq;
struct linehandle_state *lh;
struct file *file;
int fd, i, ret;
if (copy_from_user(&handlereq, ip, sizeof(handlereq)))
return -EFAULT;
if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX))
return -EINVAL;
lh = kzalloc(sizeof(*lh), GFP_KERNEL);
if (!lh)
return -ENOMEM;
lh->gdev = gdev;
get_device(&gdev->dev);
/* Make sure this is terminated */
handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0';
if (strlen(handlereq.consumer_label)) {
lh->label = kstrdup(handlereq.consumer_label,
GFP_KERNEL);
if (!lh->label) {
ret = -ENOMEM;
goto out_free_lh;
}
}
/* Request each GPIO */
for (i = 0; i < handlereq.lines; i++) {
u32 offset = handlereq.lineoffsets[i];
u32 lflags = handlereq.flags;
struct gpio_desc *desc;
if (offset >= gdev->ngpio) {
ret = -EINVAL;
goto out_free_descs;
}
/* Return an error if a unknown flag is set */
if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) {
ret = -EINVAL;
goto out_free_descs;
}
desc = &gdev->descs[offset];
ret = gpiod_request(desc, lh->label);
if (ret)
goto out_free_descs;
lh->descs[i] = desc;
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
/*
* Lines have to be requested explicitly for input
* or output, else the line will be treated "as is".
*/
if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
int val = !!handlereq.default_values[i];
ret = gpiod_direction_output(desc, val);
if (ret)
goto out_free_descs;
} else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
ret = gpiod_direction_input(desc);
if (ret)
goto out_free_descs;
}
dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
offset);
}
/* Let i point at the last handle */
i--;
lh->numdescs = handlereq.lines;
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_free_descs;
}
file = anon_inode_getfile("gpio-linehandle",
&linehandle_fileops,
lh,
O_RDONLY | O_CLOEXEC);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto out_put_unused_fd;
}
handlereq.fd = fd;
if (copy_to_user(ip, &handlereq, sizeof(handlereq))) {
/*
* fput() will trigger the release() callback, so do not go onto
* the regular error cleanup path here.
*/
fput(file);
put_unused_fd(fd);
return -EFAULT;
}
fd_install(fd, file);
dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n",
lh->numdescs);
return 0;
out_put_unused_fd:
put_unused_fd(fd);
out_free_descs:
for (; i >= 0; i--)
gpiod_free(lh->descs[i]);
kfree(lh->label);
out_free_lh:
kfree(lh);
put_device(&gdev->dev);
return ret;
}
/*
* GPIO line event management
*/
/**
* struct lineevent_state - contains the state of a userspace event
* @gdev: the GPIO device the event pertains to
* @label: consumer label used to tag descriptors
* @desc: the GPIO descriptor held by this event
* @eflags: the event flags this line was requested with
* @irq: the interrupt that trigger in response to events on this GPIO
* @wait: wait queue that handles blocking reads of events
* @events: KFIFO for the GPIO events
* @read_lock: mutex lock to protect reads from colliding with adding
* new events to the FIFO
*/
struct lineevent_state {
struct gpio_device *gdev;
const char *label;
struct gpio_desc *desc;
u32 eflags;
int irq;
wait_queue_head_t wait;
DECLARE_KFIFO(events, struct gpioevent_data, 16);
struct mutex read_lock;
};
#define GPIOEVENT_REQUEST_VALID_FLAGS \
(GPIOEVENT_REQUEST_RISING_EDGE | \
GPIOEVENT_REQUEST_FALLING_EDGE)
static unsigned int lineevent_poll(struct file *filep,
struct poll_table_struct *wait)
{
struct lineevent_state *le = filep->private_data;
unsigned int events = 0;
poll_wait(filep, &le->wait, wait);
if (!kfifo_is_empty(&le->events))
events = POLLIN | POLLRDNORM;
return events;
}
static ssize_t lineevent_read(struct file *filep,
char __user *buf,
size_t count,
loff_t *f_ps)
{
struct lineevent_state *le = filep->private_data;
unsigned int copied;
int ret;
if (count < sizeof(struct gpioevent_data))
return -EINVAL;
do {
if (kfifo_is_empty(&le->events)) {
if (filep->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_interruptible(le->wait,
!kfifo_is_empty(&le->events));
if (ret)
return ret;
}
if (mutex_lock_interruptible(&le->read_lock))
return -ERESTARTSYS;
ret = kfifo_to_user(&le->events, buf, count, &copied);
mutex_unlock(&le->read_lock);
if (ret)
return ret;
/*
* If we couldn't read anything from the fifo (a different
* thread might have been faster) we either return -EAGAIN if
* the file descriptor is non-blocking, otherwise we go back to
* sleep and wait for more data to arrive.
*/
if (copied == 0 && (filep->f_flags & O_NONBLOCK))
return -EAGAIN;
} while (copied == 0);
return copied;
}
static int lineevent_release(struct inode *inode, struct file *filep)
{
struct lineevent_state *le = filep->private_data;
struct gpio_device *gdev = le->gdev;
free_irq(le->irq, le);
gpiod_free(le->desc);
kfree(le->label);
kfree(le);
put_device(&gdev->dev);
return 0;
}
static long lineevent_ioctl(struct file *filep, unsigned int cmd,
unsigned long arg)
{
struct lineevent_state *le = filep->private_data;
void __user *ip = (void __user *)arg;
struct gpiohandle_data ghd;
/*
* We can get the value for an event line but not set it,
* because it is input by definition.
*/
if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
int val;
memset(&ghd, 0, sizeof(ghd));
val = gpiod_get_value_cansleep(le->desc);
if (val < 0)
return val;
ghd.values[0] = val;
if (copy_to_user(ip, &ghd, sizeof(ghd)))
return -EFAULT;
return 0;
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd,
unsigned long arg)
{
return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static const struct file_operations lineevent_fileops = {
.release = lineevent_release,
.read = lineevent_read,
.poll = lineevent_poll,
.owner = THIS_MODULE,
.llseek = noop_llseek,
.unlocked_ioctl = lineevent_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = lineevent_ioctl_compat,
#endif
};
static irqreturn_t lineevent_irq_thread(int irq, void *p)
{
struct lineevent_state *le = p;
struct gpioevent_data ge;
int ret, level;
ge.timestamp = ktime_get_real_ns();
level = gpiod_get_value_cansleep(le->desc);
if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
&& le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
if (level)
/* Emit low-to-high event */
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
else
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
} else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && level) {
/* Emit low-to-high event */
ge.id = GPIOEVENT_EVENT_RISING_EDGE;
} else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE && !level) {
/* Emit high-to-low event */
ge.id = GPIOEVENT_EVENT_FALLING_EDGE;
} else {
return IRQ_NONE;
}
ret = kfifo_put(&le->events, ge);
if (ret != 0)
wake_up_poll(&le->wait, POLLIN);
return IRQ_HANDLED;
}
static int lineevent_create(struct gpio_device *gdev, void __user *ip)
{
struct gpioevent_request eventreq;
struct lineevent_state *le;
struct gpio_desc *desc;
struct file *file;
u32 offset;
u32 lflags;
u32 eflags;
int fd;
int ret;
int irqflags = 0;
if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
return -EFAULT;
le = kzalloc(sizeof(*le), GFP_KERNEL);
if (!le)
return -ENOMEM;
le->gdev = gdev;
get_device(&gdev->dev);
/* Make sure this is terminated */
eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0';
if (strlen(eventreq.consumer_label)) {
le->label = kstrdup(eventreq.consumer_label,
GFP_KERNEL);
if (!le->label) {
ret = -ENOMEM;
goto out_free_le;
}
}
offset = eventreq.lineoffset;
lflags = eventreq.handleflags;
eflags = eventreq.eventflags;
if (offset >= gdev->ngpio) {
ret = -EINVAL;
goto out_free_label;
}
/* Return an error if a unknown flag is set */
if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
(eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
ret = -EINVAL;
goto out_free_label;
}
/* This is just wrong: we don't look for events on output lines */
if (lflags & GPIOHANDLE_REQUEST_OUTPUT) {
ret = -EINVAL;
goto out_free_label;
}
desc = &gdev->descs[offset];
ret = gpiod_request(desc, le->label);
if (ret)
goto out_free_desc;
le->desc = desc;
le->eflags = eflags;
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
ret = gpiod_direction_input(desc);
if (ret)
goto out_free_desc;
le->irq = gpiod_to_irq(desc);
if (le->irq <= 0) {
ret = -ENODEV;
goto out_free_desc;
}
if (eflags & GPIOEVENT_REQUEST_RISING_EDGE)
irqflags |= IRQF_TRIGGER_RISING;
if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE)
irqflags |= IRQF_TRIGGER_FALLING;
irqflags |= IRQF_ONESHOT;
irqflags |= IRQF_SHARED;
INIT_KFIFO(le->events);
init_waitqueue_head(&le->wait);
mutex_init(&le->read_lock);
/* Request a thread to read the events */
ret = request_threaded_irq(le->irq,
NULL,
lineevent_irq_thread,
irqflags,
le->label,
le);
if (ret)
goto out_free_desc;
fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_free_irq;
}
file = anon_inode_getfile("gpio-event",
&lineevent_fileops,
le,
O_RDONLY | O_CLOEXEC);
if (IS_ERR(file)) {
ret = PTR_ERR(file);
goto out_put_unused_fd;
}
eventreq.fd = fd;
if (copy_to_user(ip, &eventreq, sizeof(eventreq))) {
/*
* fput() will trigger the release() callback, so do not go onto
* the regular error cleanup path here.
*/
fput(file);
put_unused_fd(fd);
return -EFAULT;
}
fd_install(fd, file);
return 0;
out_put_unused_fd:
put_unused_fd(fd);
out_free_irq:
free_irq(le->irq, le);
out_free_desc:
gpiod_free(le->desc);
out_free_label:
kfree(le->label);
out_free_le:
kfree(le);
put_device(&gdev->dev);
return ret;
}
/*
* 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;
void __user *ip = (void __user *)arg;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!chip)
return -ENODEV;
/* Fill in the struct and pass to userspace */
if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
struct gpiochip_info chipinfo;
memset(&chipinfo, 0, sizeof(chipinfo));
strncpy(chipinfo.name, dev_name(&gdev->dev),
sizeof(chipinfo.name));
chipinfo.name[sizeof(chipinfo.name)-1] = '\0';
strncpy(chipinfo.label, gdev->label,
sizeof(chipinfo.label));
chipinfo.label[sizeof(chipinfo.label)-1] = '\0';
chipinfo.lines = gdev->ngpio;
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
return -EFAULT;
return 0;
} else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
struct gpioline_info lineinfo;
struct gpio_desc *desc;
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
return -EFAULT;
if (lineinfo.line_offset >= gdev->ngpio)
return -EINVAL;
desc = &gdev->descs[lineinfo.line_offset];
if (desc->name) {
strncpy(lineinfo.name, desc->name,
sizeof(lineinfo.name));
lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
} else {
lineinfo.name[0] = '\0';
}
if (desc->label) {
strncpy(lineinfo.consumer, desc->label,
sizeof(lineinfo.consumer));
lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
} else {
lineinfo.consumer[0] = '\0';
}
/*
* Userspace only need to know that the kernel is using
* this GPIO so it can't use it.
*/
lineinfo.flags = 0;
if (test_bit(FLAG_REQUESTED, &desc->flags) ||
test_bit(FLAG_IS_HOGGED, &desc->flags) ||
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
test_bit(FLAG_EXPORT, &desc->flags) ||
test_bit(FLAG_SYSFS, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
if (test_bit(FLAG_IS_OUT, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN;
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE;
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
return 0;
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
return linehandle_create(gdev, ip);
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
return lineevent_create(gdev, ip);
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
static long gpio_ioctl_compat(struct file *filp, unsigned int cmd,
unsigned long arg)
{
return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#endif
/**
* 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->chip)
return -ENODEV;
get_device(&gdev->dev);
filp->private_data = gdev;
return nonseekable_open(inode, filp);
}
/**
* 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);
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 = no_llseek,
.unlocked_ioctl = gpio_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = gpio_ioctl_compat,
#endif
};
static void gpiodevice_release(struct device *dev)
{
struct gpio_device *gdev = dev_get_drvdata(dev);
list_del(&gdev->list);
ida_simple_remove(&gpio_ida, gdev->id);
kfree(gdev->label);
kfree(gdev->descs);
kfree(gdev);
}
static int gpiochip_setup_dev(struct gpio_device *gdev)
{
int status;
cdev_init(&gdev->chrdev, &gpio_fileops);
gdev->chrdev.owner = THIS_MODULE;
gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
status = cdev_device_add(&gdev->chrdev, &gdev->dev);
if (status)
return status;
chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
MAJOR(gpio_devt), gdev->id);
status = gpiochip_sysfs_register(gdev);
if (status)
goto err_remove_device;
/* From this point, the .release() function cleans up gpio_device */
gdev->dev.release = gpiodevice_release;
pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n",
__func__, gdev->base, gdev->base + gdev->ngpio - 1,
dev_name(&gdev->dev), gdev->chip->label ? : "generic");
return 0;
err_remove_device:
cdev_device_del(&gdev->chrdev, &gdev->dev);
return status;
}
static void gpiochip_setup_devs(void)
{
struct gpio_device *gdev;
int err;
list_for_each_entry(gdev, &gpio_devices, list) {
err = gpiochip_setup_dev(gdev);
if (err)
pr_err("%s: Failed to initialize gpio device (%d)\n",
dev_name(&gdev->dev), err);
}
}
/**
* gpiochip_add_data() - register a gpio_chip
* @chip: the chip to register, with chip->base initialized
* @data: driver-private data associated with this chip
*
* Context: potentially before irqs will work
*
* When gpiochip_add_data() is called very early during boot, so that GPIOs
* can be freely used, the chip->parent device must be registered before
* the gpio framework's arch_initcall(). Otherwise sysfs initialization
* for GPIOs will fail rudely.
*
* gpiochip_add_data() must only be called after gpiolib initialization,
* ie after core_initcall().
*
* If chip->base is negative, this requests dynamic assignment of
* a range of valid GPIOs.
*
* Returns:
* A negative errno if the chip can't be registered, such as because the
* chip->base is invalid or already associated with a different chip.
* Otherwise it returns zero as a success code.
*/
int gpiochip_add_data(struct gpio_chip *chip, void *data)
{
unsigned long flags;
int status = 0;
unsigned i;
int base = chip->base;
struct gpio_device *gdev;
/*
* First: allocate and populate the internal stat container, and
* set up the struct device.
*/
gdev = kzalloc(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;
}
#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;
gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL);
if (!gdev->descs) {
status = -ENOMEM;
goto err_free_gdev;
}
if (chip->ngpio == 0) {
chip_err(chip, "tried to insert a GPIO chip with zero lines\n");
status = -EINVAL;
goto err_free_descs;
}
if (chip->label)
gdev->label = kstrdup(chip->label, GFP_KERNEL);
else
gdev->label = kstrdup("unknown", GFP_KERNEL);
if (!gdev->label) {
status = -ENOMEM;
goto err_free_descs;
}
gdev->ngpio = chip->ngpio;
gdev->data = data;
spin_lock_irqsave(&gpio_lock, flags);
/*
* TODO: this allocates a Linux GPIO number base in the global
* GPIO numberspace for this chip. In the long run we want to
* get *rid* of this numberspace and use only descriptors, but
* it may be a pipe dream. It will not happen before we get rid
* of the sysfs interface anyways.
*/
if (base < 0) {
base = gpiochip_find_base(chip->ngpio);
if (base < 0) {
status = base;
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_label;
}
/*
* TODO: it should not be necessary to reflect the assigned
* base outside of the GPIO subsystem. Go over drivers and
* see if anyone makes use of this, else drop this and assign
* a poison instead.
*/
chip->base = base;
}
gdev->base = base;
status = gpiodev_add_to_list(gdev);
if (status) {
spin_unlock_irqrestore(&gpio_lock, flags);
goto err_free_label;
}
spin_unlock_irqrestore(&gpio_lock, flags);
for (i = 0; i < chip->ngpio; i++) {
struct gpio_desc *desc = &gdev->descs[i];
desc->gdev = gdev;
/*
* REVISIT: most hardware initializes GPIOs as inputs
* (often with pullups enabled) so power usage is
* minimized. Linux code should set the gpio direction
* first thing; but until it does, and in case
* chip->get_direction is not set, we may expose the
* wrong direction in sysfs.
*/
if (chip->get_direction) {
/*
* If we have .get_direction, set up the initial
* direction flag from the hardware.
*/
int dir = chip->get_direction(chip, i);
if (!dir)
set_bit(FLAG_IS_OUT, &desc->flags);
} else if (!chip->direction_input) {
/*
* If the chip lacks the .direction_input callback
* we logically assume all lines are outputs.
*/
set_bit(FLAG_IS_OUT, &desc->flags);
}
}
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
#endif
status = gpiochip_set_desc_names(chip);
if (status)
goto err_remove_from_list;
status = gpiochip_irqchip_init_valid_mask(chip);
if (status)
goto err_remove_from_list;
status = of_gpiochip_add(chip);
if (status)
goto err_remove_chip;
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.
* We can do this only if gpiolib has been initialized.
* Otherwise, defer until later.
*/
if (gpiolib_initialized) {
status = gpiochip_setup_dev(gdev);
if (status)
goto err_remove_chip;
}
return 0;
err_remove_chip:
acpi_gpiochip_remove(chip);
gpiochip_free_hogs(chip);
of_gpiochip_remove(chip);
gpiochip_irqchip_free_valid_mask(chip);
err_remove_from_list:
spin_lock_irqsave(&gpio_lock, flags);
list_del(&gdev->list);
spin_unlock_irqrestore(&gpio_lock, flags);
err_free_label:
kfree(gdev->label);
err_free_descs:
kfree(gdev->descs);
err_free_gdev:
ida_simple_remove(&gpio_ida, gdev->id);
/* failures here can mean systems won't boot... */
pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
gdev->base, gdev->base + gdev->ngpio - 1,
chip->label ? : "generic");
kfree(gdev);
return status;
}
EXPORT_SYMBOL_GPL(gpiochip_add_data);
/**
* gpiochip_get_data() - get per-subdriver data for the chip
* @chip: GPIO chip
*
* Returns:
* The per-subdriver data for the chip.
*/
void *gpiochip_get_data(struct gpio_chip *chip)
{
return chip->gpiodev->data;
}
EXPORT_SYMBOL_GPL(gpiochip_get_data);
/**
* gpiochip_remove() - unregister a gpio_chip
* @chip: the chip to unregister
*
* A gpio_chip with any GPIOs still requested may not be removed.
*/
void gpiochip_remove(struct gpio_chip *chip)
{
struct gpio_device *gdev = chip->gpiodev;
struct gpio_desc *desc;
unsigned long flags;
unsigned i;
bool requested = false;
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
gpiochip_sysfs_unregister(gdev);
gpiochip_free_hogs(chip);
/* Numb the device, cancelling all outstanding operations */
gdev->chip = NULL;
gpiochip_irqchip_remove(chip);
acpi_gpiochip_remove(chip);
gpiochip_remove_pin_ranges(chip);
of_gpiochip_remove(chip);
/*
* We accept no more calls into the driver from this point, so
* NULL the driver data pointer
*/
gdev->data = NULL;
spin_lock_irqsave(&gpio_lock, flags);
for (i = 0; i < gdev->ngpio; i++) {
desc = &gdev->descs[i];
if (test_bit(FLAG_REQUESTED, &desc->flags))
requested = true;
}
spin_unlock_irqrestore(&gpio_lock, flags);
if (requested)
dev_crit(&gdev->dev,
"REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
/*
* 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.
*/
cdev_device_del(&gdev->chrdev, &gdev->dev);
put_device(&gdev->dev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);
static void devm_gpio_chip_release(struct device *dev, void *res)
{
struct gpio_chip *chip = *(struct gpio_chip **)res;
gpiochip_remove(chip);
}
static int devm_gpio_chip_match(struct device *dev, void *res, void *data)
{
struct gpio_chip **r = res;
if (!r || !*r) {
WARN_ON(!r || !*r);
return 0;
}
return *r == data;
}
/**
* devm_gpiochip_add_data() - Resource manager piochip_add_data()
* @dev: the device pointer on which irq_chip belongs to.
* @chip: the chip to register, with chip->base initialized
* @data: driver-private data associated with this chip
*
* Context: potentially before irqs will work
*
* The gpio chip automatically be released when the device is unbound.
*
* Returns:
* A negative errno if the chip can't be registered, such as because the
* chip->base is invalid or already associated with a different chip.
* Otherwise it returns zero as a success code.
*/
int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
void *data)
{
struct gpio_chip **ptr;
int ret;
ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
GFP_KERNEL);
if (!ptr)
return -ENOMEM;
ret = gpiochip_add_data(chip, data);
if (ret < 0) {
devres_free(ptr);
return ret;
}
*ptr = chip;
devres_add(dev, ptr);
return 0;
}
EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
/**
* devm_gpiochip_remove() - Resource manager of gpiochip_remove()
* @dev: device for which which resource was allocated
* @chip: the chip to remove
*
* A gpio_chip with any GPIOs still requested may not be removed.
*/
void devm_gpiochip_remove(struct device *dev, struct gpio_chip *chip)
{
int ret;
ret = devres_release(dev, devm_gpio_chip_release,
devm_gpio_chip_match, chip);
WARN_ON(ret);
}
EXPORT_SYMBOL_GPL(devm_gpiochip_remove);
/**
* gpiochip_find() - iterator for locating a specific gpio_chip
* @data: data to pass to match function
* @match: Callback function to check gpio_chip
*
* Similar to bus_find_device. It returns a reference to a gpio_chip as
* determined by a user supplied @match callback. The callback should return
* 0 if the device doesn't match and non-zero if it does. If the callback is
* non-zero, this function will return to the caller and not iterate over any
* more gpio_chips.
*/
struct gpio_chip *gpiochip_find(void *data,
int (*match)(struct gpio_chip *chip,
void *data))
{
struct gpio_device *gdev;
struct gpio_chip *chip = NULL;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list)
if (gdev->chip && match(gdev->chip, data)) {
chip = gdev->chip;
break;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return chip;
}
EXPORT_SYMBOL_GPL(gpiochip_find);
static int gpiochip_match_name(struct gpio_chip *chip, void *data)
{
const char *name = data;
return !strcmp(chip->label, name);
}
static struct gpio_chip *find_chip_by_name(const char *name)
{
return gpiochip_find((void *)name, gpiochip_match_name);
}
#ifdef CONFIG_GPIOLIB_IRQCHIP
/*
* The following is irqchip helper code for gpiochips.
*/
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
if (!gpiochip->irq_need_valid_mask)
return 0;
gpiochip->irq_valid_mask = kcalloc(BITS_TO_LONGS(gpiochip->ngpio),
sizeof(long), GFP_KERNEL);
if (!gpiochip->irq_valid_mask)
return -ENOMEM;
/* Assume by default all GPIOs are valid */
bitmap_fill(gpiochip->irq_valid_mask, gpiochip->ngpio);
return 0;
}
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
{
kfree(gpiochip->irq_valid_mask);
gpiochip->irq_valid_mask = NULL;
}
static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip,
unsigned int offset)
{
/* No mask means all valid */
if (likely(!gpiochip->irq_valid_mask))
return true;
return test_bit(offset, gpiochip->irq_valid_mask);
}
/**
* gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip chain to
* @irqchip: the irqchip to chain to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* chained irqchip
* @parent_handler: the parent interrupt handler for the accumulated IRQ
* coming out of the gpiochip. If the interrupt is nested rather than
* cascaded, pass NULL in this handler argument
*/
static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int parent_irq,
irq_flow_handler_t parent_handler)
{
unsigned int offset;
if (!gpiochip->irqdomain) {
chip_err(gpiochip, "called %s before setting up irqchip\n",
__func__);
return;
}
if (parent_handler) {
if (gpiochip->can_sleep) {
chip_err(gpiochip,
"you cannot have chained interrupts on a "
"chip that may sleep\n");
return;
}
/*
* The parent irqchip is already using the chip_data for this
* irqchip, so our callbacks simply use the handler_data.
*/
irq_set_chained_handler_and_data(parent_irq, parent_handler,
gpiochip);
gpiochip->irq_chained_parent = parent_irq;
}
/* Set the parent IRQ for all affected IRQs */
for (offset = 0; offset < gpiochip->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
continue;
irq_set_parent(irq_find_mapping(gpiochip->irqdomain, offset),
parent_irq);
}
}
/**
* gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip chain to
* @irqchip: the irqchip to chain to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* chained irqchip
* @parent_handler: the parent interrupt handler for the accumulated IRQ
* coming out of the gpiochip. If the interrupt is nested rather than
* cascaded, pass NULL in this handler argument
*/
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int parent_irq,
irq_flow_handler_t parent_handler)
{
gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
parent_handler);
}
EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
/**
* gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip
* @gpiochip: the gpiochip to set the irqchip nested handler to
* @irqchip: the irqchip to nest to the gpiochip
* @parent_irq: the irq number corresponding to the parent IRQ for this
* nested irqchip
*/
void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int parent_irq)
{
if (!gpiochip->irq_nested) {
chip_err(gpiochip, "tried to nest a chained gpiochip\n");
return;
}
gpiochip_set_cascaded_irqchip(gpiochip, irqchip, parent_irq,
NULL);
}
EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip);
/**
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
* @d: the irqdomain used by this irqchip
* @irq: the global irq number used by this GPIO irqchip irq
* @hwirq: the local IRQ/GPIO line offset on this gpiochip
*
* This function will set up the mapping for a certain IRQ line on a
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
* stored inside the gpiochip.
*/
static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct gpio_chip *chip = d->host_data;
if (!gpiochip_irqchip_irq_valid(chip, hwirq))
return -ENXIO;
irq_set_chip_data(irq, chip);
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
irq_set_lockdep_class(irq, chip->lock_key);
irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
/* Chips that use nested thread handlers have them marked */
if (chip->irq_nested)
irq_set_nested_thread(irq, 1);
irq_set_noprobe(irq);
/*
* No set-up of the hardware will happen if IRQ_TYPE_NONE
* is passed as default type.
*/
if (chip->irq_default_type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, chip->irq_default_type);
return 0;
}
static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
struct gpio_chip *chip = d->host_data;
if (chip->irq_nested)
irq_set_nested_thread(irq, 0);
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
static const struct irq_domain_ops gpiochip_domain_ops = {
.map = gpiochip_irq_map,
.unmap = gpiochip_irq_unmap,
/* Virtually all GPIO irqchips are twocell:ed */
.xlate = irq_domain_xlate_twocell,
};
static int gpiochip_irq_reqres(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
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->gpiodev->owner);
return -EINVAL;
}
return 0;
}
static void gpiochip_irq_relres(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
gpiochip_unlock_as_irq(chip, d->hwirq);
module_put(chip->gpiodev->owner);
}
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
{
if (!gpiochip_irqchip_irq_valid(chip, offset))
return -ENXIO;
return irq_create_mapping(chip->irqdomain, offset);
}
/**
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
* @gpiochip: the gpiochip to remove the irqchip from
*
* This is called only from gpiochip_remove()
*/
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
{
unsigned int offset;
acpi_gpiochip_free_interrupts(gpiochip);
if (gpiochip->irq_chained_parent) {
irq_set_chained_handler(gpiochip->irq_chained_parent, NULL);
irq_set_handler_data(gpiochip->irq_chained_parent, NULL);
}
/* Remove all IRQ mappings and delete the domain */
if (gpiochip->irqdomain) {
for (offset = 0; offset < gpiochip->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gpiochip, offset))
continue;
irq_dispose_mapping(
irq_find_mapping(gpiochip->irqdomain, offset));
}
irq_domain_remove(gpiochip->irqdomain);
}
if (gpiochip->irqchip) {
gpiochip->irqchip->irq_request_resources = NULL;
gpiochip->irqchip->irq_release_resources = NULL;
gpiochip->irqchip = NULL;
}
gpiochip_irqchip_free_valid_mask(gpiochip);
}
/**
* gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip
* @gpiochip: the gpiochip to add the irqchip to
* @irqchip: the irqchip to add to the gpiochip
* @first_irq: if not dynamically assigned, the base (first) IRQ to
* allocate gpiochip irqs from
* @handler: the irq handler to use (often a predefined irq core function)
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
* to have the core avoid setting up any default type in the hardware.
* @nested: whether this is a nested irqchip calling handle_nested_irq()
* in its IRQ handler
* @lock_key: lockdep class
*
* This function closely associates a certain irqchip with a certain
* gpiochip, providing an irq domain to translate the local IRQs to
* global irqs in the gpiolib core, and making sure that the gpiochip
* is passed as chip data to all related functions. Driver callbacks
* need to use gpiochip_get_data() to get their local state containers back
* from the gpiochip passed as chip data. An irqdomain will be stored
* in the gpiochip that shall be used by the driver to handle IRQ number
* translation. The gpiochip will need to be initialized and registered
* before calling this function.
*
* This function will handle two cell:ed simple IRQs and assumes all
* the pins on the gpiochip can generate a unique IRQ. Everything else
* need to be open coded.
*/
int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip,
struct irq_chip *irqchip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type,
bool nested,
struct lock_class_key *lock_key)
{
struct device_node *of_node;
if (!gpiochip || !irqchip)
return -EINVAL;
if (!gpiochip->parent) {
pr_err("missing gpiochip .dev parent pointer\n");
return -EINVAL;
}
gpiochip->irq_nested = nested;
of_node = gpiochip->parent->of_node;
#ifdef CONFIG_OF_GPIO
/*
* If the gpiochip has an assigned OF node this takes precedence
* FIXME: get rid of this and use gpiochip->parent->of_node
* everywhere
*/
if (gpiochip->of_node)
of_node = gpiochip->of_node;
#endif
/*
* Specifying a default trigger is a terrible idea if DT or ACPI is
* used to configure the interrupts, as you may end-up with
* conflicting triggers. Tell the user, and reset to NONE.
*/
if (WARN(of_node && type != IRQ_TYPE_NONE,
"%pOF: Ignoring %d default trigger\n", of_node, type))
type = IRQ_TYPE_NONE;
if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {
acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),
"Ignoring %d default trigger\n", type);
type = IRQ_TYPE_NONE;
}
gpiochip->irqchip = irqchip;
gpiochip->irq_handler = handler;
gpiochip->irq_default_type = type;
gpiochip->to_irq = gpiochip_to_irq;
gpiochip->lock_key = lock_key;
gpiochip->irqdomain = irq_domain_add_simple(of_node,
gpiochip->ngpio, first_irq,
&gpiochip_domain_ops, gpiochip);
if (!gpiochip->irqdomain) {
gpiochip->irqchip = NULL;
return -EINVAL;
}
/*
* It is possible for a driver to override this, but only if the
* alternative functions are both implemented.
*/
if (!irqchip->irq_request_resources &&
!irqchip->irq_release_resources) {
irqchip->irq_request_resources = gpiochip_irq_reqres;
irqchip->irq_release_resources = gpiochip_irq_relres;
}
acpi_gpiochip_request_interrupts(gpiochip);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key);
#else /* CONFIG_GPIOLIB_IRQCHIP */
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
{
return 0;
}
static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip)
{ }
#endif /* CONFIG_GPIOLIB_IRQCHIP */
/**
* gpiochip_generic_request() - request the gpio function for a pin
* @chip: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to request for GPIO function
*/
int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_request_gpio(chip->gpiodev->base + offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_request);
/**
* gpiochip_generic_free() - free the gpio function from a pin
* @chip: the gpiochip to request the gpio function for
* @offset: the offset of the GPIO to free from GPIO function
*/
void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset)
{
pinctrl_free_gpio(chip->gpiodev->base + offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_free);
/**
* gpiochip_generic_config() - apply configuration for a pin
* @chip: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to apply the configuration
* @config: the configuration to be applied
*/
int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset,
unsigned long config)
{
return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_config);
#ifdef CONFIG_PINCTRL
/**
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
* @chip: the gpiochip to add the range for
* @pctldev: the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_group: name of the pin group inside the pin controller
*/
int gpiochip_add_pingroup_range(struct gpio_chip *chip,
struct pinctrl_dev *pctldev,
unsigned int gpio_offset, const char *pin_group)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = chip->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(chip, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = chip;
pin_range->range.name = chip->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->pctldev = pctldev;
ret = pinctrl_get_group_pins(pctldev, pin_group,
&pin_range->range.pins,
&pin_range->range.npins);
if (ret < 0) {
kfree(pin_range);
return ret;
}
pinctrl_add_gpio_range(pctldev, &pin_range->range);
chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
gpio_offset, gpio_offset + pin_range->range.npins - 1,
pinctrl_dev_get_devname(pctldev), pin_group);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
/**
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
* @chip: the gpiochip to add the range for
* @pinctl_name: the dev_name() of the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_offset: the start offset in the pin controller number space
* @npins: the number of pins from the offset of each pin space (GPIO and
* pin controller) to accumulate in this range
*
* Returns:
* 0 on success, or a negative error-code on failure.
*/
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
unsigned int npins)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = chip->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(chip, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = chip;
pin_range->range.name = chip->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->range.pin_base = pin_offset;
pin_range->range.npins = npins;
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
&pin_range->range);
if (IS_ERR(pin_range->pctldev)) {
ret = PTR_ERR(pin_range->pctldev);
chip_err(chip, "could not create pin range\n");
kfree(pin_range);
return ret;
}
chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
gpio_offset, gpio_offset + npins - 1,
pinctl_name,
pin_offset, pin_offset + npins - 1);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
/**
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
* @chip: the chip to remove all the mappings for
*/
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
{
struct gpio_pin_range *pin_range, *tmp;
struct gpio_device *gdev = chip->gpiodev;
list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
list_del(&pin_range->node);
pinctrl_remove_gpio_range(pin_range->pctldev,
&pin_range->range);
kfree(pin_range);
}
}
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
#endif /* CONFIG_PINCTRL */
/* These "optional" allocation calls help prevent drivers from stomping
* on each other, and help provide better diagnostics in debugfs.
* They're called even less than the "set direction" calls.
*/
static int __gpiod_request(struct gpio_desc *desc, const char *label)
{
struct gpio_chip *chip = desc->gdev->chip;
int status;
unsigned long flags;
spin_lock_irqsave(&gpio_lock, flags);
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
desc_set_label(desc, label ? : "?");
status = 0;
} else {
status = -EBUSY;
goto done;
}
if (chip->request) {
/* chip->request may sleep */
spin_unlock_irqrestore(&gpio_lock, flags);
status = chip->request(chip, gpio_chip_hwgpio(desc));
spin_lock_irqsave(&gpio_lock, flags);
if (status < 0) {
desc_set_label(desc, NULL);
clear_bit(FLAG_REQUESTED, &desc->flags);
goto done;
}
}
if (chip->get_direction) {
/* chip->get_direction may sleep */
spin_unlock_irqrestore(&gpio_lock, flags);
gpiod_get_direction(desc);
spin_lock_irqsave(&gpio_lock, flags);
}
done:
spin_unlock_irqrestore(&gpio_lock, flags);
return status;
}
/*
* This descriptor validation needs to be inserted verbatim into each
* function taking a descriptor, so we need to use a preprocessor
* macro to avoid endless duplication. If the desc is NULL it is an
* optional GPIO and calls should just bail out.
*/
#define VALIDATE_DESC(desc) do { \
if (!desc) \
return 0; \
if (IS_ERR(desc)) { \
pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
return PTR_ERR(desc); \
} \
if (!desc->gdev) { \
pr_warn("%s: invalid GPIO (no device)\n", __func__); \
return -EINVAL; \
} \
if ( !desc->gdev->chip ) { \
dev_warn(&desc->gdev->dev, \
"%s: backing chip is gone\n", __func__); \
return 0; \
} } while (0)
#define VALIDATE_DESC_VOID(desc) do { \
if (!desc) \
return; \
if (IS_ERR(desc)) { \
pr_warn("%s: invalid GPIO (errorpointer)\n", __func__); \
return; \
} \
if (!desc->gdev) { \
pr_warn("%s: invalid GPIO (no device)\n", __func__); \
return; \
} \
if (!desc->gdev->chip) { \
dev_warn(&desc->gdev->dev, \
"%s: backing chip is gone\n", __func__); \
return; \
} } while (0)
int gpiod_request(struct gpio_desc *desc, const char *label)
{
int status = -EPROBE_DEFER;
struct gpio_device *gdev;
VALIDATE_DESC(desc);
gdev = desc->gdev;
if (try_module_get(gdev->owner)) {
status = __gpiod_request(desc, label);
if (status < 0)
module_put(gdev->owner);
else
get_device(&gdev->dev);
}
if (status)
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
return status;
}
static bool __gpiod_free(struct gpio_desc *desc)
{
bool ret = false;
unsigned long flags;
struct gpio_chip *chip;
might_sleep();
gpiod_unexport(desc);
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->gdev->chip;
if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
if (chip->free) {
spin_unlock_irqrestore(&gpio_lock, flags);
might_sleep_if(chip->can_sleep);
chip->free(chip, gpio_chip_hwgpio(desc));
spin_lock_irqsave(&gpio_lock, flags);
}
desc_set_label(desc, NULL);
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
clear_bit(FLAG_REQUESTED, &desc->flags);
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
ret = true;
}
spin_unlock_irqrestore(&gpio_lock, flags);
return ret;
}
void gpiod_free(struct gpio_desc *desc)
{
if (desc && desc->gdev && __gpiod_free(desc)) {
module_put(desc->gdev->owner);
put_device(&desc->gdev->dev);
} else {
WARN_ON(extra_checks);
}
}
/**
* gpiochip_is_requested - return string iff signal was requested
* @chip: controller managing the signal
* @offset: of signal within controller's 0..(ngpio - 1) range
*
* Returns NULL if the GPIO is not currently requested, else a string.
* The string returned is the label passed to gpio_request(); if none has been
* passed it is a meaningless, non-NULL constant.
*
* This function is for use by GPIO controller drivers. The label can
* help with diagnostics, and knowing that the signal is used as a GPIO
* can help avoid accidentally multiplexing it to another controller.
*/
const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
{
struct gpio_desc *desc;
if (offset >= chip->ngpio)
return NULL;
desc = &chip->gpiodev->descs[offset];
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
return NULL;
return desc->label;
}
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
/**
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
* @chip: GPIO chip
* @hwnum: hardware number of the GPIO for which to request the descriptor
* @label: label for the GPIO
*
* Function allows GPIO chip drivers to request and use their own GPIO
* descriptors via gpiolib API. Difference to gpiod_request() is that this
* function will not increase reference count of the GPIO chip module. This
* allows the GPIO chip module to be unloaded as needed (we assume that the
* GPIO chip driver handles freeing the GPIOs it has requested).
*
* Returns:
* A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
* code on failure.
*/
struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum,
const char *label)
{
struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum);
int err;
if (IS_ERR(desc)) {
chip_err(chip, "failed to get GPIO descriptor\n");
return desc;
}
err = __gpiod_request(desc, label);
if (err < 0)
return ERR_PTR(err);
return desc;
}
EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
/**
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
* @desc: GPIO descriptor to free
*
* Function frees the given GPIO requested previously with
* gpiochip_request_own_desc().
*/
void gpiochip_free_own_desc(struct gpio_desc *desc)
{
if (desc)
__gpiod_free(desc);
}
EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
/*
* Drivers MUST set GPIO direction before making get/set calls. In
* some cases this is done in early boot, before IRQs are enabled.
*
* As a rule these aren't called more than once (except for drivers
* using the open-drain emulation idiom) so these are natural places
* to accumulate extra debugging checks. Note that we can't (yet)
* rely on gpio_request() having been called beforehand.
*/
/**
* gpiod_direction_input - set the GPIO direction to input
* @desc: GPIO to set to input
*
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
* be called safely on it.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_input(struct gpio_desc *desc)
{
struct gpio_chip *chip;
int status = -EINVAL;
VALIDATE_DESC(desc);
chip = desc->gdev->chip;
if (!chip->get || !chip->direction_input) {
gpiod_warn(desc,
"%s: missing get() or direction_input() operations\n",
__func__);
return -EIO;
}
status = chip->direction_input(chip, gpio_chip_hwgpio(desc));
if (status == 0)
clear_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_direction(desc_to_gpio(desc), 1, status);
return status;
}
EXPORT_SYMBOL_GPL(gpiod_direction_input);
static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset,
enum pin_config_param mode)
{
unsigned long config = { PIN_CONF_PACKED(mode, 0) };
return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
}
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
struct gpio_chip *gc = desc->gdev->chip;
int val = !!value;
int ret;
/* GPIOs used for IRQs shall not be set as output */
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
gpiod_err(desc,
"%s: tried to set a GPIO tied to an IRQ as output\n",
__func__);
return -EIO;
}
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
/* First see if we can enable open drain in hardware */
ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
PIN_CONFIG_DRIVE_OPEN_DRAIN);
if (!ret)
goto set_output_value;
/* Emulate open drain by not actively driving the line high */
if (val)
return gpiod_direction_input(desc);
}
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
PIN_CONFIG_DRIVE_OPEN_SOURCE);
if (!ret)
goto set_output_value;
/* Emulate open source by not actively driving the line low */
if (!val)
return gpiod_direction_input(desc);
} else {
gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),
PIN_CONFIG_DRIVE_PUSH_PULL);
}
set_output_value:
if (!gc->set || !gc->direction_output) {
gpiod_warn(desc,
"%s: missing set() or direction_output() operations\n",
__func__);
return -EIO;
}
ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_value(desc_to_gpio(desc), 0, val);
trace_gpio_direction(desc_to_gpio(desc), 0, ret);
return ret;
}
/**
* gpiod_direction_output_raw - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as raw value on the physical line without regard for the ACTIVE_LOW status.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
VALIDATE_DESC(desc);
return _gpiod_direction_output_raw(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
/**
* gpiod_direction_output - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account.
*
* Return 0 in case of success, else an error code.
*/
int gpiod_direction_output(struct gpio_desc *desc, int value)
{
VALIDATE_DESC(desc);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
else
value = !!value;
return _gpiod_direction_output_raw(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
/**
* gpiod_set_debounce - sets @debounce time for a GPIO
* @desc: descriptor of the GPIO for which to set debounce time
* @debounce: debounce time in microseconds
*
* Returns:
* 0 on success, %-ENOTSUPP if the controller doesn't support setting the
* debounce time.
*/
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
struct gpio_chip *chip;
unsigned long config;
VALIDATE_DESC(desc);
chip = desc->gdev->chip;
if (!chip->set || !chip->set_config) {
gpiod_dbg(desc,
"%s: missing set() or set_config() operations\n",
__func__);
return -ENOTSUPP;
}
config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
}
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
/**
* gpiod_is_active_low - test whether a GPIO is active-low or not
* @desc: the gpio descriptor to test
*
* Returns 1 if the GPIO is active-low, 0 otherwise.
*/
int gpiod_is_active_low(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
/* I/O calls are only valid after configuration completed; the relevant
* "is this a valid GPIO" error checks should already have been done.
*
* "Get" operations are often inlinable as reading a pin value register,
* and masking the relevant bit in that register.
*
* When "set" operations are inlinable, they involve writing that mask to
* one register to set a low value, or a different register to set it high.
* Otherwise locking is needed, so there may be little value to inlining.
*
*------------------------------------------------------------------------
*
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
* have requested the GPIO. That can include implicit requesting by
* a direction setting call. Marking a gpio as requested locks its chip
* in memory, guaranteeing that these table lookups need no more locking
* and that gpiochip_remove() will fail.
*
* REVISIT when debugging, consider adding some instrumentation to ensure
* that the GPIO was actually requested.
*/
static int _gpiod_get_raw_value(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
int value;
chip = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
value = chip->get ? chip->get(chip, offset) : -EIO;
value = value < 0 ? value : !!value;
trace_gpio_value(desc_to_gpio(desc), 1, value);
return value;
}
/**
* gpiod_get_raw_value() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_raw_value(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
/* Should be using gpio_get_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
return _gpiod_get_raw_value(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
/**
* gpiod_get_value() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_value(const struct gpio_desc *desc)
{
int value;
VALIDATE_DESC(desc);
/* Should be using gpio_get_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
value = _gpiod_get_raw_value(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value);
/*
* _gpio_set_open_drain_value() - Set the open drain gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
{
int err = 0;
struct gpio_chip *chip = desc->gdev->chip;
int offset = gpio_chip_hwgpio(desc);
if (value) {
err = chip->direction_input(chip, offset);
if (!err)
clear_bit(FLAG_IS_OUT, &desc->flags);
} else {
err = chip->direction_output(chip, offset, 0);
if (!err)
set_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), value, err);
if (err < 0)
gpiod_err(desc,
"%s: Error in set_value for open drain err %d\n",
__func__, err);
}
/*
* _gpio_set_open_source_value() - Set the open source gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
{
int err = 0;
struct gpio_chip *chip = desc->gdev->chip;
int offset = gpio_chip_hwgpio(desc);
if (value) {
err = chip->direction_output(chip, offset, 1);
if (!err)
set_bit(FLAG_IS_OUT, &desc->flags);
} else {
err = chip->direction_input(chip, offset);
if (!err)
clear_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), !value, err);
if (err < 0)
gpiod_err(desc,
"%s: Error in set_value for open source err %d\n",
__func__, err);
}
static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
{
struct gpio_chip *chip;
chip = desc->gdev->chip;
trace_gpio_value(desc_to_gpio(desc), 0, value);
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
_gpio_set_open_drain_value(desc, value);
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
_gpio_set_open_source_value(desc, value);
else
chip->set(chip, gpio_chip_hwgpio(desc), value);
}
/*
* set multiple outputs on the same chip;
* use the chip's set_multiple function if available;
* otherwise set the outputs sequentially;
* @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
* defines which outputs are to be changed
* @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
* defines the values the outputs specified by mask are to be set to
*/
static void gpio_chip_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
if (chip->set_multiple) {
chip->set_multiple(chip, mask, bits);
} else {
unsigned int i;
/* set outputs if the corresponding mask bit is set */
for_each_set_bit(i, mask, chip->ngpio)
chip->set(chip, i, test_bit(i, bits));
}
}
void gpiod_set_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
int *value_array)
{
int i = 0;
while (i < array_size) {
struct gpio_chip *chip = desc_array[i]->gdev->chip;
unsigned long mask[BITS_TO_LONGS(chip->ngpio)];
unsigned long bits[BITS_TO_LONGS(chip->ngpio)];
int count = 0;
if (!can_sleep)
WARN_ON(chip->can_sleep);
memset(mask, 0, sizeof(mask));
do {
struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
int value = value_array[i];
if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
trace_gpio_value(desc_to_gpio(desc), 0, value);
/*
* collect all normal outputs belonging to the same chip
* open drain and open source outputs are set individually
*/
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
_gpio_set_open_drain_value(desc, value);
} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
_gpio_set_open_source_value(desc, value);
} else {
__set_bit(hwgpio, mask);
if (value)
__set_bit(hwgpio, bits);
else
__clear_bit(hwgpio, bits);
count++;
}
i++;
} while ((i < array_size) &&
(desc_array[i]->gdev->chip == chip));
/* push collected bits to outputs */
if (count != 0)
gpio_chip_set_multiple(chip, mask, bits);
}
}
/**
* gpiod_set_raw_value() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
_gpiod_set_raw_value(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
/**
* gpiod_set_value() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->chip->can_sleep);
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
_gpiod_set_raw_value(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value);
/**
* gpiod_set_raw_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor / value arrays
* @desc_array: array of GPIO descriptors whose values will be assigned
* @value_array: array of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array)
{
if (!desc_array)
return;
gpiod_set_array_value_complex(true, false, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
/**
* gpiod_set_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor / value arrays
* @desc_array: array of GPIO descriptors whose values will be assigned
* @value_array: array of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function should be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array, int *value_array)
{
if (!desc_array)
return;
gpiod_set_array_value_complex(false, false, array_size, desc_array,
value_array);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value);
/**
* gpiod_cansleep() - report whether gpio value access may sleep
* @desc: gpio to check
*
*/
int gpiod_cansleep(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return desc->gdev->chip->can_sleep;
}
EXPORT_SYMBOL_GPL(gpiod_cansleep);
/**
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
* @desc: gpio whose IRQ will be returned (already requested)
*
* Return the IRQ corresponding to the passed GPIO, or an error code in case of
* error.
*/
int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_chip *chip;
int offset;
/*
* Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
* requires this function to not return zero on an invalid descriptor
* but rather a negative error number.
*/
if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
return -EINVAL;
chip = desc->gdev->chip;
offset = gpio_chip_hwgpio(desc);
if (chip->to_irq) {
int retirq = chip->to_irq(chip, offset);
/* Zero means NO_IRQ */
if (!retirq)
return -ENXIO;
return retirq;
}
return -ENXIO;
}
EXPORT_SYMBOL_GPL(gpiod_to_irq);
/**
* gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
* @chip: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to lock down
* a certain GPIO line to be used for IRQs.
*/
int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(chip, offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
/*
* If it's fast: flush the direction setting if something changed
* behind our back
*/
if (!chip->can_sleep && chip->get_direction) {
int dir = chip->get_direction(chip, offset);
if (dir)
clear_bit(FLAG_IS_OUT, &desc->flags);
else
set_bit(FLAG_IS_OUT, &desc->flags);
}
if (test_bit(FLAG_IS_OUT, &desc->flags)) {
chip_err(chip,
"%s: tried to flag a GPIO set as output for IRQ\n",
__func__);
return -EIO;
}
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
/*
* If the consumer has not set up a label (such as when the
* IRQ is referenced from .to_irq()) we set up a label here
* so it is clear this is used as an interrupt.
*/
if (!desc->label)
desc_set_label(desc, "interrupt");
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
/**
* gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
* @chip: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to indicate
* that a certain GPIO is no longer used exclusively for IRQ.
*/
void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(chip, offset);
if (IS_ERR(desc))
return;
clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
/* If we only had this marking, erase it */
if (desc->label && !strcmp(desc->label, "interrupt"))
desc_set_label(desc, NULL);
}
EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)
return false;
return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)
return false;
return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
{
if (offset >= chip->ngpio)