[PATCH v11 17/19] input: cyapa: add read sensors raw data debugfs interface support

[Dudley Du <dudley.dulixin@gmail.com>]

Add read sensors' raw data from trackpad device interface supported in cyapa
driver through debugfs raw_data interface.
Through this interface, user can read difference count map of each sensors
directly from trackpad device (some customers want). And it's useful to help
users to find out the root cause when there is performance gap happened.
TEST=test on Chromebooks.

Signed-off-by: Dudley Du <dudley.dulixin@gmail.com>
---
 drivers/input/mouse/cyapa.c | 105 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/input/mouse/cyapa.h |   4 ++
 2 files changed, 109 insertions(+)

diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
index 2e394c0..ca31119 100644
--- a/drivers/input/mouse/cyapa.c
+++ b/drivers/input/mouse/cyapa.c
@@ -34,6 +34,7 @@
 #define CYAPA_ADAPTER_FUNC_BOTH   3
 
 #define CYAPA_DEBUGFS_READ_FW	"read_fw"
+#define CYAPA_DEBUGFS_RAW_DATA	"raw_data"
 #define CYAPA_FW_NAME		"cyapa.bin"
 
 const char unique_str[] = "CYTRA";
@@ -604,6 +605,106 @@ static const struct file_operations cyapa_read_fw_fops = {
 	.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 error;
+
+	if (!cyapa)
+		return -ENODEV;
+
+	/* Start to be supported after Gen5 trackpad devices. */
+	if (cyapa->gen < CYAPA_GEN5)
+		return -ENOTSUPP;
+
+	error = mutex_lock_interruptible(&cyapa->debugfs_mutex);
+	if (error)
+		return error;
+
+	if (!get_device(&cyapa->client->dev)) {
+		error = -ENODEV;
+		goto out;
+	}
+
+	file->private_data = cyapa;
+
+	/*
+	 * Enale IRQ for raw data read command, and must be enable during
+	 * the whole process.
+	 */
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		goto out;
+	cyapa_enable_irq_for_cmd(cyapa);
+	mutex_unlock(&cyapa->state_sync_lock);
+out:
+	mutex_unlock(&cyapa->debugfs_mutex);
+	return error;
+}
+
+static int cyapa_debugfs_raw_data_release(struct inode *inode,
+				struct file *file)
+{
+	struct cyapa *cyapa = file->private_data;
+	int error;
+
+	if (!cyapa)
+		return 0;
+
+	/* Disable IRQ if enabled when raw_data file was opened. */
+	mutex_lock(&cyapa->state_sync_lock);
+	cyapa_disable_irq_for_cmd(cyapa);
+	mutex_unlock(&cyapa->state_sync_lock);
+
+	error = mutex_lock_interruptible(&cyapa->debugfs_mutex);
+	if (error)
+		return error;
+	file->private_data = NULL;
+	put_device(&cyapa->client->dev);
+	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)
+{
+	int error;
+	struct cyapa *cyapa = file->private_data;
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+
+	if (cyapa->ops->read_raw_data)
+		error = cyapa->ops->read_raw_data(cyapa);
+	else
+		error = -EPERM;
+	mutex_unlock(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+
+	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;
@@ -622,6 +723,10 @@ static int cyapa_debugfs_init(struct cyapa *cyapa)
 	debugfs_create_file(CYAPA_DEBUGFS_READ_FW, S_IRUSR, cyapa->dentry_dev,
 			    cyapa, &cyapa_read_fw_fops);
 
+	if (cyapa->gen >= CYAPA_GEN5)
+		debugfs_create_file(CYAPA_DEBUGFS_RAW_DATA, S_IRUSR,
+			cyapa->dentry_dev, cyapa, &cyapa_read_raw_data_fops);
+
 	return 0;
 }
 
diff --git a/drivers/input/mouse/cyapa.h b/drivers/input/mouse/cyapa.h
index b6e1b22..9dbf92f 100644
--- a/drivers/input/mouse/cyapa.h
+++ b/drivers/input/mouse/cyapa.h
@@ -187,6 +187,7 @@ struct cyapa_dev_ops {
 			struct device_attribute *, const char *, size_t);
 
 	int (*read_fw)(struct cyapa *);
+	int (*read_raw_data)(struct cyapa *);
 
 	int (*initialize)(struct cyapa *cyapa);
 
@@ -308,6 +309,9 @@ struct cyapa {
 	struct cyapa_tsg_bin_image_head fw_img_head;
 	u8 *fw_image;
 	size_t fw_image_size;
+	/* Buffer to store sensors' raw data */
+	u8 *tp_raw_data;
+	size_t tp_raw_data_size;
 
 	const struct cyapa_dev_ops *ops;
 
-- 
1.9.1