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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.c108
1 files changed, 58 insertions, 50 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 9dad67ea2597..ef08b23a56e2 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -89,6 +89,10 @@ struct linehandle_state {
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
+#define GPIOHANDLE_REQUEST_DIRECTION_FLAGS \
+ (GPIOHANDLE_REQUEST_INPUT | \
+ GPIOHANDLE_REQUEST_OUTPUT)
+
static int linehandle_validate_flags(u32 flags)
{
/* Return an error if an unknown flag is set */
@@ -169,21 +173,21 @@ static long linehandle_set_config(struct linehandle_state *lh,
if (ret)
return ret;
+ /* Lines must be reconfigured explicitly as input or output. */
+ if (!(lflags & GPIOHANDLE_REQUEST_DIRECTION_FLAGS))
+ return -EINVAL;
+
for (i = 0; i < lh->num_descs; i++) {
desc = lh->descs[i];
- linehandle_flags_to_desc_flags(gcnf.flags, &desc->flags);
+ linehandle_flags_to_desc_flags(lflags, &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 = !!gcnf.default_values[i];
ret = gpiod_direction_output(desc, val);
if (ret)
return ret;
- } else if (lflags & GPIOHANDLE_REQUEST_INPUT) {
+ } else {
ret = gpiod_direction_input(desc);
if (ret)
return ret;
@@ -1128,6 +1132,14 @@ static void edge_detector_stop(struct line *line)
/* do not change line->level - see comment in debounced_value() */
}
+static int edge_detector_fifo_init(struct linereq *req)
+{
+ if (kfifo_initialized(&req->events))
+ return 0;
+
+ return kfifo_alloc(&req->events, req->event_buffer_size, GFP_KERNEL);
+}
+
static int edge_detector_setup(struct line *line,
struct gpio_v2_line_config *lc,
unsigned int line_idx, u64 edflags)
@@ -1139,9 +1151,8 @@ static int edge_detector_setup(struct line *line,
char *label;
eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS;
- if (eflags && !kfifo_initialized(&line->req->events)) {
- ret = kfifo_alloc(&line->req->events,
- line->req->event_buffer_size, GFP_KERNEL);
+ if (eflags) {
+ ret = edge_detector_fifo_init(line->req);
if (ret)
return ret;
}
@@ -1193,8 +1204,6 @@ static int edge_detector_update(struct line *line,
struct gpio_v2_line_config *lc,
unsigned int line_idx, u64 edflags)
{
- u64 eflags;
- int ret;
u64 active_edflags = READ_ONCE(line->edflags);
unsigned int debounce_period_us =
gpio_v2_line_config_debounce_period(lc, line_idx);
@@ -1210,14 +1219,9 @@ static int edge_detector_update(struct line *line,
* ensure event fifo is initialised if edge detection
* is now enabled.
*/
- eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS;
- if (eflags && !kfifo_initialized(&line->req->events)) {
- ret = kfifo_alloc(&line->req->events,
- line->req->event_buffer_size,
- GFP_KERNEL);
- if (ret)
- return ret;
- }
+ if (edflags & GPIO_V2_LINE_EDGE_FLAGS)
+ return edge_detector_fifo_init(line->req);
+
return 0;
}
@@ -1530,12 +1534,14 @@ static long linereq_set_config(struct linereq *lr, void __user *ip)
line = &lr->lines[i];
desc = lr->lines[i].desc;
flags = gpio_v2_line_config_flags(&lc, i);
- gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
- edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS;
/*
- * Lines have to be requested explicitly for input
- * or output, else the line will be treated "as is".
+ * Lines not explicitly reconfigured as input or output
+ * are left unchanged.
*/
+ if (!(flags & GPIO_V2_LINE_DIRECTION_FLAGS))
+ continue;
+ gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
+ edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS;
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
int val = gpio_v2_line_config_output_value(&lc, i);
@@ -1543,7 +1549,7 @@ static long linereq_set_config(struct linereq *lr, void __user *ip)
ret = gpiod_direction_output(desc, val);
if (ret)
return ret;
- } else if (flags & GPIO_V2_LINE_FLAG_INPUT) {
+ } else {
ret = gpiod_direction_input(desc);
if (ret)
return ret;
@@ -1642,16 +1648,15 @@ static ssize_t linereq_read(struct file *file, char __user *buf,
return ret;
}
- ret = kfifo_out(&lr->events, &le, 1);
- }
- if (ret != 1) {
- /*
- * This should never happen - we were holding the
- * lock from the moment we learned the fifo is no
- * longer empty until now.
- */
- ret = -EIO;
- break;
+ if (kfifo_out(&lr->events, &le, 1) != 1) {
+ /*
+ * This should never happen - we hold the
+ * lock from the moment we learned the fifo
+ * is no longer empty until now.
+ */
+ WARN(1, "failed to read from non-empty kfifo");
+ return -EIO;
+ }
}
if (copy_to_user(buf + bytes_read, &le, sizeof(le)))
@@ -1774,6 +1779,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
mutex_init(&lr->config_mutex);
init_waitqueue_head(&lr->wait);
+ INIT_KFIFO(lr->events);
lr->event_buffer_size = ulr.event_buffer_size;
if (lr->event_buffer_size == 0)
lr->event_buffer_size = ulr.num_lines * 16;
@@ -1994,16 +2000,15 @@ static ssize_t lineevent_read(struct file *file, char __user *buf,
return ret;
}
- ret = kfifo_out(&le->events, &ge, 1);
- }
- if (ret != 1) {
- /*
- * This should never happen - we were holding the lock
- * from the moment we learned the fifo is no longer
- * empty until now.
- */
- ret = -EIO;
- break;
+ if (kfifo_out(&le->events, &ge, 1) != 1) {
+ /*
+ * This should never happen - we hold the
+ * lock from the moment we learned the fifo
+ * is no longer empty until now.
+ */
+ WARN(1, "failed to read from non-empty kfifo");
+ return -EIO;
+ }
}
if (copy_to_user(buf + bytes_read, &ge, ge_size))
@@ -2706,12 +2711,15 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf,
if (count < event_size)
return -EINVAL;
#endif
- ret = kfifo_out(&cdev->events, &event, 1);
- }
- if (ret != 1) {
- ret = -EIO;
- break;
- /* We should never get here. See lineevent_read(). */
+ if (kfifo_out(&cdev->events, &event, 1) != 1) {
+ /*
+ * This should never happen - we hold the
+ * lock from the moment we learned the fifo
+ * is no longer empty until now.
+ */
+ WARN(1, "failed to read from non-empty kfifo");
+ return -EIO;
+ }
}
#ifdef CONFIG_GPIO_CDEV_V1
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-19 01:36:17 +0300