@@ -47,6 +47,7 @@ enum {
struct gpio_mockup_line_status {
int dir;
int value;
+ int pull;
};
struct gpio_mockup_chip {
@@ -188,15 +189,56 @@ static int gpio_mockup_to_irq(struct gpio_chip *gc, unsigned int offset)
return irq_sim_irqnum(&chip->irqsim, offset);
}
-static ssize_t gpio_mockup_event_write(struct file *file,
- const char __user *usr_buf,
- size_t size, loff_t *ppos)
+static void gpio_mockup_free(struct gpio_chip *gc, unsigned int offset)
+{
+ struct gpio_mockup_chip *chip = gpiochip_get_data(gc);
+
+ __gpio_mockup_set(chip, offset, chip->lines[offset].pull);
+}
+
+static ssize_t gpio_mockup_debugfs_read(struct file *file,
+ char __user *usr_buf,
+ size_t size, loff_t *ppos)
+{
+ struct gpio_mockup_dbgfs_private *priv;
+ struct gpio_mockup_chip *chip;
+ struct seq_file *sfile;
+ struct gpio_chip *gc;
+ char buf[3];
+ int val, rv;
+
+ if (*ppos != 0)
+ return 0;
+
+ sfile = file->private_data;
+ priv = sfile->private;
+ chip = priv->chip;
+ gc = &chip->gc;
+
+ val = gpio_mockup_get(gc, priv->offset);
+ snprintf(buf, sizeof(buf), "%d\n", val);
+
+ rv = copy_to_user(usr_buf, buf, sizeof(buf));
+ if (rv)
+ return rv;
+
+ return sizeof(buf) - 1;
+}
+
+static ssize_t gpio_mockup_debugfs_write(struct file *file,
+ const char __user *usr_buf,
+ size_t size, loff_t *ppos)
{
struct gpio_mockup_dbgfs_private *priv;
struct gpio_mockup_chip *chip;
struct seq_file *sfile;
struct gpio_desc *desc;
- int rv, val;
+ unsigned int irq_type;
+ struct gpio_chip *gc;
+ int rv, val, curr;
+
+ if (*ppos != 0)
+ return -EINVAL;
rv = kstrtoint_from_user(usr_buf, size, 0, &val);
if (rv)
@@ -206,24 +248,66 @@ static ssize_t gpio_mockup_event_write(struct file *file,
sfile = file->private_data;
priv = sfile->private;
- desc = priv->desc;
chip = priv->chip;
+ gc = &chip->gc;
+ desc = &gc->gpiodev->descs[priv->offset];
+
+ mutex_lock(&chip->lock);
- gpiod_set_value_cansleep(desc, val);
- irq_sim_fire(&chip->irqsim, priv->offset);
+ if (test_bit(FLAG_REQUESTED, &desc->flags) &&
+ !test_bit(FLAG_IS_OUT, &desc->flags)) {
+ curr = __gpio_mockup_get(chip, priv->offset);
+ if (curr == val)
+ goto out;
+
+ irq_type = val == 0 ? IRQ_TYPE_EDGE_FALLING
+ : IRQ_TYPE_EDGE_RISING;
+ irq_sim_fire_type(&chip->irqsim, priv->offset, irq_type);
+ }
+
+ /* Change the value unless we're actively driving the line. */
+ if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
+ !test_bit(FLAG_IS_OUT, &desc->flags))
+ __gpio_mockup_set(chip, priv->offset, val);
+
+out:
+ chip->lines[priv->offset].pull = val;
+ mutex_unlock(&chip->lock);
return size;
}
-static int gpio_mockup_event_open(struct inode *inode, struct file *file)
+static int gpio_mockup_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, NULL, inode->i_private);
}
-static const struct file_operations gpio_mockup_event_ops = {
+/*
+ * Each mockup chip is represented by a directory named after the chip's device
+ * name under /sys/kernel/debug/gpio-mockup/. Each line is represented by
+ * a file using the line's offset as the name under the chip's directory.
+ *
+ * Reading from the line's file yields the current *value*, writing to the
+ * line's file changes the current *pull*. Default pull for mockup lines is
+ * down.
+ *
+ * Examples:
+ * - when a line pulled down is requested in output mode and driven high, its
+ * value will return to 0 once it's released
+ * - when the line is requested in output mode and driven high, writing 0 to
+ * the corresponding debugfs file will change the pull to down but the
+ * reported value will still be 1 until the line is released
+ * - line requested in input mode always reports the same value as its pull
+ * configuration
+ * - when the line is requested in input mode and monitored for events, writing
+ * the same value to the debugfs file will be a noop, while writing the
+ * opposite value will generate a dummy interrupt with an appropriate edge
+ */
+static const struct file_operations gpio_mockup_debugfs_ops = {
.owner = THIS_MODULE,
- .open = gpio_mockup_event_open,
- .write = gpio_mockup_event_write,
+ .open = gpio_mockup_debugfs_open,
+ .read = gpio_mockup_debugfs_read,
+ .write = gpio_mockup_debugfs_write,
.llseek = no_llseek,
};
@@ -258,7 +342,7 @@ static void gpio_mockup_debugfs_setup(struct device *dev,
priv->desc = &gc->gpiodev->descs[i];
evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
- &gpio_mockup_event_ops);
+ &gpio_mockup_debugfs_ops);
if (IS_ERR_OR_NULL(evfile))
goto err;
}
@@ -266,7 +350,7 @@ static void gpio_mockup_debugfs_setup(struct device *dev,
return;
err:
- dev_err(dev, "error creating debugfs event files\n");
+ dev_err(dev, "error creating debugfs files\n");
}
static int gpio_mockup_name_lines(struct device *dev,
@@ -342,6 +426,7 @@ static int gpio_mockup_probe(struct platform_device *pdev)
gc->direction_input = gpio_mockup_dirin;
gc->get_direction = gpio_mockup_get_direction;
gc->to_irq = gpio_mockup_to_irq;
+ gc->free = gpio_mockup_free;
chip->lines = devm_kcalloc(dev, gc->ngpio,
sizeof(*chip->lines), GFP_KERNEL);
@@ -415,7 +500,7 @@ static int __init gpio_mockup_init(void)
return -EINVAL;
}
- gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
+ gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup", NULL);
if (IS_ERR_OR_NULL(gpio_mockup_dbg_dir))
gpio_mockup_err("error creating debugfs directory\n");