#include <linux/overflow.h>
#include <linux/pinctrl/consumer.h>
#include <linux/poll.h>
-#include <linux/rbtree.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/timekeeping.h>
/**
* struct line - contains the state of a requested line
- * @node: to store the object in supinfo_tree if supplemental
* @desc: the GPIO descriptor for this line.
* @req: the corresponding line request
* @irq: the interrupt triggered in response to events on this GPIO
* @line_seqno: the seqno for the current edge event in the sequence of
* events for this line.
* @work: the worker that implements software debouncing
- * @debounce_period_us: the debounce period in microseconds
* @sw_debounced: flag indicating if the software debouncer is active
* @level: the current debounced physical level of the line
* @hdesc: the Hardware Timestamp Engine (HTE) descriptor
* @last_seqno: the last sequence number before debounce period expires
*/
struct line {
- struct rb_node node;
struct gpio_desc *desc;
/*
* -- edge detector specific fields --
* -- debouncer specific fields --
*/
struct delayed_work work;
- /*
- * debounce_period_us is accessed by debounce_irq_handler() and
- * process_hw_ts() which are disabled when modified by
- * debounce_setup(), edge_detector_setup() or edge_detector_stop()
- * or can live with a stale version when updated by
- * edge_detector_update().
- * The modifying functions are themselves mutually exclusive.
- */
- unsigned int debounce_period_us;
/*
* sw_debounce is accessed by linereq_set_config(), which is the
* only setter, and linereq_get_values(), which can live with a
#endif /* CONFIG_HTE */
};
-/*
- * a rbtree of the struct lines containing supplemental info.
- * Used to populate gpio_v2_line_info with cdev specific fields not contained
- * in the struct gpio_desc.
- * A line is determined to contain supplemental information by
- * line_has_supinfo().
- */
-static struct rb_root supinfo_tree = RB_ROOT;
-/* covers supinfo_tree */
-static DEFINE_SPINLOCK(supinfo_lock);
-
/**
* struct linereq - contains the state of a userspace line request
* @gdev: the GPIO device the line request pertains to
* this line request. Note that this is not used when @num_lines is 1, as
* the line_seqno is then the same and is cheaper to calculate.
* @config_mutex: mutex for serializing ioctl() calls to ensure consistency
- * of configuration, particularly multi-step accesses to desc flags and
- * changes to supinfo status.
+ * of configuration, particularly multi-step accesses to desc flags.
* @lines: the lines held by this line request, with @num_lines elements.
*/
struct linereq {
struct line lines[] __counted_by(num_lines);
};
-static void supinfo_insert(struct line *line)
-{
- struct rb_node **new = &(supinfo_tree.rb_node), *parent = NULL;
- struct line *entry;
-
- guard(spinlock)(&supinfo_lock);
-
- while (*new) {
- entry = container_of(*new, struct line, node);
-
- parent = *new;
- if (line->desc < entry->desc) {
- new = &((*new)->rb_left);
- } else if (line->desc > entry->desc) {
- new = &((*new)->rb_right);
- } else {
- /* this should never happen */
- WARN(1, "duplicate line inserted");
- return;
- }
- }
-
- rb_link_node(&line->node, parent, new);
- rb_insert_color(&line->node, &supinfo_tree);
-}
-
-static void supinfo_erase(struct line *line)
-{
- guard(spinlock)(&supinfo_lock);
-
- rb_erase(&line->node, &supinfo_tree);
-}
-
-static struct line *supinfo_find(struct gpio_desc *desc)
-{
- struct rb_node *node = supinfo_tree.rb_node;
- struct line *line;
-
- while (node) {
- line = container_of(node, struct line, node);
- if (desc < line->desc)
- node = node->rb_left;
- else if (desc > line->desc)
- node = node->rb_right;
- else
- return line;
- }
- return NULL;
-}
-
-static void supinfo_to_lineinfo(struct gpio_desc *desc,
- struct gpio_v2_line_info *info)
-{
- struct gpio_v2_line_attribute *attr;
- struct line *line;
-
- guard(spinlock)(&supinfo_lock);
-
- line = supinfo_find(desc);
- if (!line)
- return;
-
- attr = &info->attrs[info->num_attrs];
- attr->id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
- attr->debounce_period_us = READ_ONCE(line->debounce_period_us);
- info->num_attrs++;
-}
-
-static inline bool line_has_supinfo(struct line *line)
-{
- return READ_ONCE(line->debounce_period_us);
-}
-
-/*
- * Checks line_has_supinfo() before and after the change to avoid unnecessary
- * supinfo_tree access.
- * Called indirectly by linereq_create() or linereq_set_config() so line
- * is already protected from concurrent changes.
- */
-static void line_set_debounce_period(struct line *line,
- unsigned int debounce_period_us)
-{
- bool was_suppl = line_has_supinfo(line);
-
- WRITE_ONCE(line->debounce_period_us, debounce_period_us);
-
- /* if supinfo status is unchanged then we're done */
- if (line_has_supinfo(line) == was_suppl)
- return;
-
- /* supinfo status has changed, so update the tree */
- if (was_suppl)
- supinfo_erase(line);
- else
- supinfo_insert(line);
-}
-
#define GPIO_V2_LINE_BIAS_FLAGS \
(GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \
GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \
line->total_discard_seq++;
line->last_seqno = ts->seq;
mod_delayed_work(system_wq, &line->work,
- usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));
+ usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us)));
} else {
if (unlikely(ts->seq < line->line_seqno))
return HTE_CB_HANDLED;
struct line *line = p;
mod_delayed_work(system_wq, &line->work,
- usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));
+ usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us)));
return IRQ_HANDLED;
}
/* try hardware */
ret = gpiod_set_debounce(line->desc, debounce_period_us);
if (!ret) {
- line_set_debounce_period(line, debounce_period_us);
+ WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
return ret;
}
if (ret != -ENOTSUPP)
cancel_delayed_work_sync(&line->work);
WRITE_ONCE(line->sw_debounced, 0);
WRITE_ONCE(line->edflags, 0);
- line_set_debounce_period(line, 0);
+ if (line->desc)
+ WRITE_ONCE(line->desc->debounce_period_us, 0);
/* do not change line->level - see comment in debounced_value() */
}
ret = debounce_setup(line, debounce_period_us);
if (ret)
return ret;
- line_set_debounce_period(line, debounce_period_us);
+ WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
}
/* detection disabled or sw debouncer will provide edge detection */
gpio_v2_line_config_debounce_period(lc, line_idx);
if ((active_edflags == edflags) &&
- (READ_ONCE(line->debounce_period_us) == debounce_period_us))
+ (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us))
return 0;
/* sw debounced and still will be...*/
if (debounce_period_us && READ_ONCE(line->sw_debounced)) {
- line_set_debounce_period(line, debounce_period_us);
+ WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
/*
* ensure event fifo is initialised if edge detection
* is now enabled.
static void linereq_free(struct linereq *lr)
{
- struct line *line;
unsigned int i;
if (lr->device_unregistered_nb.notifier_call)
&lr->device_unregistered_nb);
for (i = 0; i < lr->num_lines; i++) {
- line = &lr->lines[i];
- if (!line->desc)
- continue;
-
- edge_detector_stop(line);
- if (line_has_supinfo(line))
- supinfo_erase(line);
- gpiod_free(line->desc);
+ if (lr->lines[i].desc) {
+ edge_detector_stop(&lr->lines[i]);
+ gpiod_free(lr->lines[i].desc);
+ }
}
kfifo_free(&lr->events);
kfree(lr->label);
static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
struct gpio_v2_line_info *info)
{
+ u32 debounce_period_us;
unsigned long dflags;
const char *label;
info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME;
else if (test_bit(FLAG_EVENT_CLOCK_HTE, &dflags))
info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE;
+
+ debounce_period_us = READ_ONCE(desc->debounce_period_us);
+ if (debounce_period_us) {
+ info->attrs[info->num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
+ info->attrs[info->num_attrs].debounce_period_us =
+ debounce_period_us;
+ info->num_attrs++;
+ }
}
struct gpio_chardev_data {
return -EBUSY;
}
gpio_desc_to_lineinfo(desc, &lineinfo);
- supinfo_to_lineinfo(desc, &lineinfo);
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
if (watch)
chg.event_type = action;
chg.timestamp_ns = ktime_get_ns();
gpio_desc_to_lineinfo(desc, &chg.info);
- supinfo_to_lineinfo(desc, &chg.info);
ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock);
if (ret)
projects / thirdparty / linux.git / commitdiff
