Re: [PATCH v4 5/14] input: cyapa: add read firmware image and raw data interfaces in debugfs system

[Dmitry Torokhov]

Hi Dudley,

On Thu, Jul 17, 2014 at 02:52:36PM +0800, Dudley Du wrote:
> Add read_fw and raw_data debugfs interfaces for easier issues location
> and collection when report by user.
> TEST=test on Chromebooks.
> 
> Signed-off-by: Dudley Du <dudl@xxxxxxxxxxx>
> ---
>  drivers/input/mouse/cyapa.c |  219 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 219 insertions(+)
> 
> diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
> index 53c9d59..ae24b02 100644
> --- a/drivers/input/mouse/cyapa.c
> +++ b/drivers/input/mouse/cyapa.c
> @@ -39,6 +39,8 @@
>  
>  const char unique_str[] = "CYTRA";
>  
> +/* Global root node of the cyapa debugfs directory. */
> +static struct dentry *cyapa_debugfs_root;
>  
>  
>  ssize_t cyapa_i2c_reg_read_block(struct cyapa *cyapa, u8 reg, size_t len,
> @@ -461,6 +463,205 @@ done:
>  }
>  
>  /*
> + **************************************************************
> + * debugfs interface
> + **************************************************************
> +*/
> +static int cyapa_debugfs_open(struct inode *inode, struct file *file)
> +{
> +	struct cyapa *cyapa = inode->i_private;
> +	int ret;
> +
> +	if (!cyapa)
> +		return -ENODEV;
> +
> +	ret = mutex_lock_interruptible(&cyapa->debugfs_mutex);
> +	if (ret)
> +		return ret;
> +
> +	if (!kobject_get(&cyapa->client->dev.kobj)) {

Why not get_device() here and elsewhere?

> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	file->private_data = cyapa;
> +
> +	if (cyapa->fw_image) {
> +		ret = 0;
> +		goto out;
> +	}
> +
> +	mutex_lock(&cyapa->state_sync_lock);
> +	/*
> +	 * If firmware hasn't been read yet, read it all in one pass.
> +	 * Subsequent opens will reuse the data in this same buffer.
> +	 */
> +	if (cyapa->ops->read_fw)
> +		ret = cyapa->ops->read_fw(cyapa);
> +	else
> +		ret = -EPERM;
> +	mutex_unlock(&cyapa->state_sync_lock);
> +
> +	/* Redetect trackpad device states. */
> +	cyapa_detect_async(cyapa, 0);
> +
> +out:
> +	mutex_unlock(&cyapa->debugfs_mutex);
> +	return ret;
> +}
> +
> +static int cyapa_debugfs_release(struct inode *inode, struct file *file)
> +{
> +	struct cyapa *cyapa = file->private_data;
> +	int ret;
> +
> +	if (!cyapa)
> +		return 0;
> +
> +	ret = mutex_lock_interruptible(&cyapa->debugfs_mutex);
> +	if (ret)
> +		return ret;
> +	file->private_data = NULL;
> +	kobject_put(&cyapa->client->dev.kobj);
> +	mutex_unlock(&cyapa->debugfs_mutex);
> +
> +	return 0;
> +}
> +
> +/* Return some bytes from the buffered firmware image, starting from *ppos */
> +static ssize_t cyapa_debugfs_read_fw(struct file *file, char __user *buffer,
> +				     size_t count, loff_t *ppos)
> +{
> +	struct cyapa *cyapa = file->private_data;
> +
> +	if (!cyapa->fw_image)
> +		return -EINVAL;
> +
> +	if (*ppos >= cyapa->fw_image_size)
> +		return 0;
> +
> +	if (count + *ppos > cyapa->fw_image_size)
> +		count = cyapa->fw_image_size - *ppos;
> +
> +	if (copy_to_user(buffer, &cyapa->fw_image[*ppos], count))
> +		return -EFAULT;
> +
> +	*ppos += count;
> +	return count;
> +}
> +
> +static const struct file_operations cyapa_read_fw_fops = {
> +	.open = cyapa_debugfs_open,
> +	.release = cyapa_debugfs_release,
> +	.read = cyapa_debugfs_read_fw
> +};
> +
> +static int cyapa_debugfs_raw_data_open(struct inode *inode, struct file *file)
> +{
> +	struct cyapa *cyapa = inode->i_private;
> +	int ret;
> +
> +	if (!cyapa)
> +		return -ENODEV;
> +
> +	/* Start to be supported after Gen5 trackpad devices. */
> +	if (cyapa->gen < CYAPA_GEN5)
> +		return -ENOTSUPP;
> +
> +	ret = mutex_lock_interruptible(&cyapa->debugfs_mutex);
> +	if (ret)
> +		return ret;
> +
> +	if (!kobject_get(&cyapa->client->dev.kobj)) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	file->private_data = cyapa;
> +
> +	mutex_lock(&cyapa->state_sync_lock);
> +	if (cyapa->ops->read_raw_data)
> +		ret = cyapa->ops->read_raw_data(cyapa);
> +	else
> +		ret = -EPERM;
> +	mutex_unlock(&cyapa->state_sync_lock);
> +out:
> +	mutex_unlock(&cyapa->debugfs_mutex);
> +	return ret;
> +}
> +
> +static int cyapa_debugfs_raw_data_release(struct inode *inode,
> +				struct file *file)
> +{
> +	struct cyapa *cyapa = file->private_data;
> +	int ret;
> +
> +	if (!cyapa)
> +		return 0;
> +
> +	ret = mutex_lock_interruptible(&cyapa->debugfs_mutex);
> +	if (ret)
> +		return ret;
> +	file->private_data = NULL;
> +	kobject_put(&cyapa->client->dev.kobj);
> +	mutex_unlock(&cyapa->debugfs_mutex);
> +
> +	return 0;
> +}
> +
> +/* Always return the sensors' latest raw data from trackpad device. */
> +static ssize_t cyapa_debugfs_read_raw_data(struct file *file,
> +				     char __user *buffer,
> +				     size_t count, loff_t *ppos)
> +{
> +	struct cyapa *cyapa = file->private_data;
> +
> +	if (!cyapa->tp_raw_data)
> +		return -EINVAL;
> +
> +	if (*ppos >= cyapa->tp_raw_data_size)
> +		return 0;
> +
> +	if (count + *ppos > cyapa->tp_raw_data_size)
> +		count = cyapa->tp_raw_data_size - *ppos;
> +
> +	if (copy_to_user(buffer, &cyapa->tp_raw_data[*ppos], count))
> +		return -EFAULT;
> +
> +	*ppos += count;
> +	return count;
> +}
> +
> +static const struct file_operations cyapa_read_raw_data_fops = {
> +	.open = cyapa_debugfs_raw_data_open,
> +	.release = cyapa_debugfs_raw_data_release,
> +	.read = cyapa_debugfs_read_raw_data
> +};
> +
> +static int cyapa_debugfs_init(struct cyapa *cyapa)
> +{
> +	struct device *dev = &cyapa->client->dev;
> +
> +	if (!cyapa_debugfs_root)
> +		return -ENODEV;
> +
> +	cyapa->dentry_dev = debugfs_create_dir(kobject_name(&dev->kobj),
> +					       cyapa_debugfs_root);
> +
> +	if (!cyapa->dentry_dev)
> +		return -ENODEV;
> +
> +	mutex_init(&cyapa->debugfs_mutex);
> +
> +	debugfs_create_file(CYAPA_DEBUGFS_READ_FW, S_IRUSR, cyapa->dentry_dev,
> +			    cyapa, &cyapa_read_fw_fops);
> +
> +	debugfs_create_file(CYAPA_DEBUGFS_RAW_DATA, S_IRUSR, cyapa->dentry_dev,
> +			    cyapa, &cyapa_read_raw_data_fops);
> +	return 0;
> +}
> +
> +/*
>   * Sysfs Interface.
>   */
>  
> @@ -869,6 +1070,13 @@ static int cyapa_probe(struct i2c_client *client,
>  	if (sysfs_create_group(&client->dev.kobj, &cyapa_sysfs_group))
>  		dev_warn(dev, "error creating sysfs entries.\n");
>  
> +	/* Create a global debugfs root for all cyapa devices */
> +	cyapa_debugfs_root = debugfs_create_dir("cyapa", NULL);
> +	if (cyapa_debugfs_root == ERR_PTR(-ENODEV))
> +		cyapa_debugfs_root = NULL;
> +	if (cyapa_debugfs_init(cyapa))
> +		dev_warn(dev, "error creating debugfs entries.\n");
> +
>  #ifdef CONFIG_PM_SLEEP
>  	if (device_can_wakeup(dev) &&
>  	    sysfs_merge_group(&client->dev.kobj, &cyapa_power_wakeup_group))
> @@ -902,8 +1110,19 @@ static int cyapa_remove(struct i2c_client *client)
>  #ifdef CONFIG_PM_RUNTIME
>  	sysfs_unmerge_group(&client->dev.kobj, &cyapa_power_runtime_group);
>  #endif
> +
> +	kfree(cyapa->fw_image);
> +	cyapa->fw_image = NULL;
> +	cyapa->fw_image_size = 0;
> +	kfree(cyapa->tp_raw_data);
> +	cyapa->tp_raw_data = NULL;
> +	cyapa->tp_raw_data_size = 0;

This should be happening only after you remove debugfs entries.


>  	free_irq(cyapa->irq, cyapa);
>  
> +	debugfs_remove_recursive(cyapa->dentry_dev);
> +	debugfs_remove_recursive(cyapa_debugfs_root);

Hm, it seems that your debugfs entries are created per-devce, but you remove
all of them at one when very first device us unbound. You probably want to
create and destroy root of your debugfs hierarchy on module level.

> +	mutex_destroy(&cyapa->debugfs_mutex);
> +
>  	input_unregister_device(cyapa->input);
>  	if (cyapa->ops->set_power_mode)
>  		cyapa->ops->set_power_mode(cyapa, PWR_MODE_OFF, 0);
> -- 
> 1.7.9.5
> 
> 

Thanks.

-- 
Dmitry
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