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path: root/drivers/gpio/gpiolib-cdev.c
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Diffstat (limited to 'drivers/gpio/gpiolib-cdev.c')
-rw-r--r--drivers/gpio/gpiolib-cdev.c79
1 files changed, 49 insertions, 30 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index e9faeaf65d14..12b679ca552c 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -428,6 +428,12 @@ struct line {
*/
struct linereq *req;
unsigned int irq;
+ /*
+ * eflags is set by edge_detector_setup(), edge_detector_stop() and
+ * edge_detector_update(), which are themselves mutually exclusive,
+ * and is accessed by edge_irq_thread() and debounce_work_func(),
+ * which can both live with a slightly stale value.
+ */
u64 eflags;
/*
* timestamp_ns and req_seqno are accessed only by
@@ -504,11 +510,14 @@ struct linereq {
(GPIO_V2_LINE_FLAG_EDGE_RISING | \
GPIO_V2_LINE_FLAG_EDGE_FALLING)
+#define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS
+
#define GPIO_V2_LINE_VALID_FLAGS \
(GPIO_V2_LINE_FLAG_ACTIVE_LOW | \
GPIO_V2_LINE_DIRECTION_FLAGS | \
GPIO_V2_LINE_DRIVE_FLAGS | \
GPIO_V2_LINE_EDGE_FLAGS | \
+ GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \
GPIO_V2_LINE_BIAS_FLAGS)
static void linereq_put_event(struct linereq *lr,
@@ -529,11 +538,20 @@ static void linereq_put_event(struct linereq *lr,
pr_debug_ratelimited("event FIFO is full - event dropped\n");
}
+static u64 line_event_timestamp(struct line *line)
+{
+ if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags))
+ return ktime_get_real_ns();
+
+ return ktime_get_ns();
+}
+
static irqreturn_t edge_irq_thread(int irq, void *p)
{
struct line *line = p;
struct linereq *lr = line->req;
struct gpio_v2_line_event le;
+ u64 eflags;
/* Do not leak kernel stack to userspace */
memset(&le, 0, sizeof(le));
@@ -546,14 +564,14 @@ static irqreturn_t edge_irq_thread(int irq, void *p)
* which case we didn't get the timestamp from
* edge_irq_handler().
*/
- le.timestamp_ns = ktime_get_ns();
+ le.timestamp_ns = line_event_timestamp(line);
if (lr->num_lines != 1)
line->req_seqno = atomic_inc_return(&lr->seqno);
}
line->timestamp_ns = 0;
- if (line->eflags == (GPIO_V2_LINE_FLAG_EDGE_RISING |
- GPIO_V2_LINE_FLAG_EDGE_FALLING)) {
+ eflags = READ_ONCE(line->eflags);
+ if (eflags == GPIO_V2_LINE_FLAG_EDGE_BOTH) {
int level = gpiod_get_value_cansleep(line->desc);
if (level)
@@ -562,10 +580,10 @@ static irqreturn_t edge_irq_thread(int irq, void *p)
else
/* Emit high-to-low event */
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
- } else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) {
+ } else if (eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) {
/* Emit low-to-high event */
le.id = GPIO_V2_LINE_EVENT_RISING_EDGE;
- } else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) {
+ } else if (eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) {
/* Emit high-to-low event */
le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE;
} else {
@@ -590,7 +608,7 @@ static irqreturn_t edge_irq_handler(int irq, void *p)
* Just store the timestamp in hardirq context so we get it as
* close in time as possible to the actual event.
*/
- line->timestamp_ns = ktime_get_ns();
+ line->timestamp_ns = line_event_timestamp(line);
if (lr->num_lines != 1)
line->req_seqno = atomic_inc_return(&lr->seqno);
@@ -634,6 +652,7 @@ static void debounce_work_func(struct work_struct *work)
struct line *line = container_of(work, struct line, work.work);
struct linereq *lr;
int level;
+ u64 eflags;
level = gpiod_get_raw_value_cansleep(line->desc);
if (level < 0) {
@@ -647,7 +666,8 @@ static void debounce_work_func(struct work_struct *work)
WRITE_ONCE(line->level, level);
/* -- edge detection -- */
- if (!line->eflags)
+ eflags = READ_ONCE(line->eflags);
+ if (!eflags)
return;
/* switch from physical level to logical - if they differ */
@@ -655,15 +675,15 @@ static void debounce_work_func(struct work_struct *work)
level = !level;
/* ignore edges that are not being monitored */
- if (((line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) ||
- ((line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level))
+ if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) ||
+ ((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level))
return;
/* Do not leak kernel stack to userspace */
memset(&le, 0, sizeof(le));
lr = line->req;
- le.timestamp_ns = ktime_get_ns();
+ le.timestamp_ns = line_event_timestamp(line);
le.offset = gpio_chip_hwgpio(line->desc);
line->line_seqno++;
le.line_seqno = line->line_seqno;
@@ -755,7 +775,7 @@ static void edge_detector_stop(struct line *line)
cancel_delayed_work_sync(&line->work);
WRITE_ONCE(line->sw_debounced, 0);
- line->eflags = 0;
+ WRITE_ONCE(line->eflags, 0);
/* do not change line->level - see comment in debounced_value() */
}
@@ -774,7 +794,7 @@ static int edge_detector_setup(struct line *line,
if (ret)
return ret;
}
- line->eflags = eflags;
+ WRITE_ONCE(line->eflags, eflags);
if (gpio_v2_line_config_debounced(lc, line_idx)) {
debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx);
ret = debounce_setup(line, debounce_period_us);
@@ -817,13 +837,13 @@ static int edge_detector_update(struct line *line,
unsigned int debounce_period_us =
gpio_v2_line_config_debounce_period(lc, line_idx);
- if ((line->eflags == eflags) && !polarity_change &&
+ if ((READ_ONCE(line->eflags) == eflags) && !polarity_change &&
(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->eflags = eflags;
+ WRITE_ONCE(line->eflags, eflags);
WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us);
return 0;
}
@@ -967,6 +987,9 @@ static void gpio_v2_line_config_flags_to_desc_flags(u64 flags,
flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN);
assign_bit(FLAG_BIAS_DISABLE, flagsp,
flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED);
+
+ assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp,
+ flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME);
}
static long linereq_get_values(struct linereq *lr, void __user *ip)
@@ -1479,21 +1502,10 @@ static __poll_t lineevent_poll(struct file *file,
return events;
}
-static ssize_t lineevent_get_size(void)
-{
-#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
- /* i386 has no padding after 'id' */
- if (in_ia32_syscall()) {
- struct compat_gpioeevent_data {
- compat_u64 timestamp;
- u32 id;
- };
-
- return sizeof(struct compat_gpioeevent_data);
- }
-#endif
- return sizeof(struct gpioevent_data);
-}
+struct compat_gpioeevent_data {
+ compat_u64 timestamp;
+ u32 id;
+};
static ssize_t lineevent_read(struct file *file,
char __user *buf,
@@ -1515,7 +1527,10 @@ static ssize_t lineevent_read(struct file *file,
* actual sizeof() and pass this as an argument to copy_to_user() to
* drop unneeded bytes from the output.
*/
- ge_size = lineevent_get_size();
+ if (compat_need_64bit_alignment_fixup())
+ ge_size = sizeof(struct compat_gpioeevent_data);
+ else
+ ge_size = sizeof(struct gpioevent_data);
if (count < ge_size)
return -EINVAL;
@@ -1910,6 +1925,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
test_bit(FLAG_EXPORT, &desc->flags) ||
test_bit(FLAG_SYSFS, &desc->flags) ||
+ !gpiochip_line_is_valid(gc, info->offset) ||
!ok_for_pinctrl)
info->flags |= GPIO_V2_LINE_FLAG_USED;
@@ -1938,6 +1954,9 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
if (test_bit(FLAG_EDGE_FALLING, &desc->flags))
info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING;
+ if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags))
+ info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME;
+
debounce_period_us = READ_ONCE(desc->debounce_period_us);
if (debounce_period_us) {
info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE;
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-21 16:19:55 +0000