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gpio: mockup: implement event injecting over debugfs

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Create a debugfs directory for every mockup chip and a single file
for every line. Writing (0 or 1) to these files allows the user to
inject line events (falling or rising edge respectively).

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Bartosz Golaszewski 2017-02-06 15:11:08 +01:00 committed by Linus Walleij
parent e2ff740895
commit 9202ba2397
1 changed files with 115 additions and 1 deletions
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116
drivers/gpio/gpio-mockup.c
View File

@ -14,11 +14,16 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irq_work.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include "gpiolib.h"
#define GPIO_MOCKUP_NAME "gpio-mockup"
#define GPIO_MOCKUP_MAX_GC 10
@ -47,6 +52,13 @@ struct gpio_mockup_chip {
struct gpio_chip gc;
struct gpio_mockup_line_status *lines;
struct gpio_mockup_irq_context irq_ctx;
struct dentry *dbg_dir;
};
struct gpio_mockup_dbgfs_private {
struct gpio_mockup_chip *chip;
struct gpio_desc *desc;
int offset;
};
static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
@ -58,6 +70,7 @@ module_param_named(gpio_mockup_named_lines,
gpio_mockup_named_lines, bool, 0400);
static const char gpio_mockup_name_start = 'A';
static struct dentry *gpio_mockup_dbg_dir;
static int gpio_mockup_get(struct gpio_chip *gc, unsigned int offset)
{
@ -175,6 +188,94 @@ static int gpio_mockup_irqchip_setup(struct device *dev,
return 0;
}
static ssize_t gpio_mockup_event_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;
struct gpio_chip *gc;
int status, val;
char buf;
sfile = file->private_data;
priv = sfile->private;
desc = priv->desc;
chip = priv->chip;
gc = &chip->gc;
status = copy_from_user(&buf, usr_buf, 1);
if (status)
return status;
if (buf == '0')
val = 0;
else if (buf == '1')
val = 1;
else
return -EINVAL;
gpiod_set_value_cansleep(desc, val);
priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
irq_work_queue(&priv->chip->irq_ctx.work);
return size;
}
static int gpio_mockup_event_open(struct inode *inode, struct file *file)
{
return single_open(file, NULL, inode->i_private);
}
static const struct file_operations gpio_mockup_event_ops = {
.owner = THIS_MODULE,
.open = gpio_mockup_event_open,
.write = gpio_mockup_event_write,
.llseek = no_llseek,
};
static void gpio_mockup_debugfs_setup(struct device *dev,
struct gpio_mockup_chip *chip)
{
struct gpio_mockup_dbgfs_private *priv;
struct dentry *evfile;
struct gpio_chip *gc;
char *name;
int i;
gc = &chip->gc;
chip->dbg_dir = debugfs_create_dir(gc->label, gpio_mockup_dbg_dir);
if (!chip->dbg_dir)
goto err;
for (i = 0; i < gc->ngpio; i++) {
name = devm_kasprintf(dev, GFP_KERNEL, "%d", i);
if (!name)
goto err;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
goto err;
priv->chip = chip;
priv->offset = i;
priv->desc = &gc->gpiodev->descs[i];
evfile = debugfs_create_file(name, 0200, chip->dbg_dir, priv,
&gpio_mockup_event_ops);
if (!evfile)
goto err;
}
return;
err:
dev_err(dev, "error creating debugfs directory\n");
}
static int gpio_mockup_add(struct device *dev,
struct gpio_mockup_chip *chip,
const char *name, int base, int ngpio)
@ -209,7 +310,14 @@ static int gpio_mockup_add(struct device *dev,
if (ret)
return ret;
return devm_gpiochip_add_data(dev, &chip->gc, chip);
ret = devm_gpiochip_add_data(dev, &chip->gc, chip);
if (ret)
return ret;
if (gpio_mockup_dbg_dir)
gpio_mockup_debugfs_setup(dev, chip);
return 0;
}
static int gpio_mockup_probe(struct platform_device *pdev)
@ -291,6 +399,11 @@ static int __init mock_device_init(void)
{
int err;
gpio_mockup_dbg_dir = debugfs_create_dir("gpio-mockup-event", NULL);
if (!gpio_mockup_dbg_dir)
pr_err("%s: error creating debugfs directory\n",
GPIO_MOCKUP_NAME);
pdev = platform_device_alloc(GPIO_MOCKUP_NAME, -1);
if (!pdev)
return -ENOMEM;
@ -312,6 +425,7 @@ static int __init mock_device_init(void)
static void __exit mock_device_exit(void)
{
debugfs_remove_recursive(gpio_mockup_dbg_dir);
platform_driver_unregister(&gpio_mockup_driver);
platform_device_unregister(pdev);
}