HID: elo: add quirks for broken firmware
One firmare version in the devices the driver takes care of is
completely broken and needs periodic pokes from our side. We
implemented this as a periodic delayed queue. The idea of the pokes
was taken from the suse enterprise kernel, in particular from Libor's
"Elo touchscreen firmware M workaround".
I am quoting him here:
This patch adds periodic polling of the Elo USB touchscreens. Needed
as a workaround for devices with M-level firmware, otherwise these
devices are known to misbehave (as reported by Elo developers).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Petr Ostadal <postadal@suse.cz>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Egbert Eich <eich@suse.com>
Cc: Libor Pechacek <lpechacek@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-elo.c b/drivers/hid/hid-elo.c
index 56143e0..f042a6c 100644
--- a/drivers/hid/hid-elo.c
+++ b/drivers/hid/hid-elo.c
@@ -11,9 +11,32 @@
#include <linux/hid.h>
#include <linux/input.h>
#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/workqueue.h>
#include "hid-ids.h"
+#define ELO_PERIODIC_READ_INTERVAL HZ
+#define ELO_SMARTSET_CMD_TIMEOUT 2000 /* msec */
+
+/* Elo SmartSet commands */
+#define ELO_FLUSH_SMARTSET_RESPONSES 0x02 /* Flush all pending smartset responses */
+#define ELO_SEND_SMARTSET_COMMAND 0x05 /* Send a smartset command */
+#define ELO_GET_SMARTSET_RESPONSE 0x06 /* Get a smartset response */
+#define ELO_DIAG 0x64 /* Diagnostics command */
+#define ELO_SMARTSET_PACKET_SIZE 8
+
+struct elo_priv {
+ struct usb_device *usbdev;
+ struct delayed_work work;
+ unsigned char buffer[ELO_SMARTSET_PACKET_SIZE];
+};
+
+static struct workqueue_struct *wq;
+static bool use_fw_quirk = true;
+module_param(use_fw_quirk, bool, S_IRUGO);
+MODULE_PARM_DESC(use_fw_quirk, "Do periodic pokes for broken M firmwares (default = true)");
+
static void elo_input_configured(struct hid_device *hdev,
struct hid_input *hidinput)
{
@@ -73,10 +96,108 @@
return 0;
}
+static int elo_smartset_send_get(struct usb_device *dev, u8 command,
+ void *data)
+{
+ unsigned int pipe;
+ u8 dir;
+
+ if (command == ELO_SEND_SMARTSET_COMMAND) {
+ pipe = usb_sndctrlpipe(dev, 0);
+ dir = USB_DIR_OUT;
+ } else if (command == ELO_GET_SMARTSET_RESPONSE) {
+ pipe = usb_rcvctrlpipe(dev, 0);
+ dir = USB_DIR_IN;
+ } else
+ return -EINVAL;
+
+ return usb_control_msg(dev, pipe, command,
+ dir | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+ 0, 0, data, ELO_SMARTSET_PACKET_SIZE,
+ ELO_SMARTSET_CMD_TIMEOUT);
+}
+
+static int elo_flush_smartset_responses(struct usb_device *dev)
+{
+ return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+ ELO_FLUSH_SMARTSET_RESPONSES,
+ USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+ 0, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
+}
+
+static void elo_work(struct work_struct *work)
+{
+ struct elo_priv *priv = container_of(work, struct elo_priv, work.work);
+ struct usb_device *dev = priv->usbdev;
+ unsigned char *buffer = priv->buffer;
+ int ret;
+
+ ret = elo_flush_smartset_responses(dev);
+ if (ret < 0) {
+ dev_err(&dev->dev, "initial FLUSH_SMARTSET_RESPONSES failed, error %d\n",
+ ret);
+ goto fail;
+ }
+
+ /* send Diagnostics command */
+ *buffer = ELO_DIAG;
+ ret = elo_smartset_send_get(dev, ELO_SEND_SMARTSET_COMMAND, buffer);
+ if (ret < 0) {
+ dev_err(&dev->dev, "send Diagnostics Command failed, error %d\n",
+ ret);
+ goto fail;
+ }
+
+ /* get the result */
+ ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE, buffer);
+ if (ret < 0) {
+ dev_err(&dev->dev, "get Diagnostics Command response failed, error %d\n",
+ ret);
+ goto fail;
+ }
+
+ /* read the ack */
+ if (*buffer != 'A') {
+ ret = elo_smartset_send_get(dev, ELO_GET_SMARTSET_RESPONSE,
+ buffer);
+ if (ret < 0) {
+ dev_err(&dev->dev, "get acknowledge response failed, error %d\n",
+ ret);
+ goto fail;
+ }
+ }
+
+fail:
+ ret = elo_flush_smartset_responses(dev);
+ if (ret < 0)
+ dev_err(&dev->dev, "final FLUSH_SMARTSET_RESPONSES failed, error %d\n",
+ ret);
+ queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
+}
+
+/*
+ * Not all Elo devices need the periodic HID descriptor reads.
+ * Only firmware version M needs this.
+ */
+static bool elo_broken_firmware(struct usb_device *dev)
+{
+ return use_fw_quirk && le16_to_cpu(dev->descriptor.bcdDevice) == 0x10d;
+}
+
static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
+ struct elo_priv *priv;
int ret;
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ INIT_DELAYED_WORK(&priv->work, elo_work);
+ priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
+
+ hid_set_drvdata(hdev, priv);
+
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "parse failed\n");
@@ -89,14 +210,24 @@
goto err_free;
}
+ if (elo_broken_firmware(priv->usbdev)) {
+ hid_info(hdev, "broken firmware found, installing workaround\n");
+ queue_delayed_work(wq, &priv->work, ELO_PERIODIC_READ_INTERVAL);
+ }
+
return 0;
err_free:
+ kfree(priv);
return ret;
}
static void elo_remove(struct hid_device *hdev)
{
+ struct elo_priv *priv = hid_get_drvdata(hdev);
+
hid_hw_stop(hdev);
+ flush_workqueue(wq);
+ kfree(priv);
}
static const struct hid_device_id elo_devices[] = {
@@ -117,13 +248,24 @@
static int __init elo_driver_init(void)
{
- return hid_register_driver(&elo_driver);
+ int ret;
+
+ wq = create_singlethread_workqueue("elousb");
+ if (!wq)
+ return -ENOMEM;
+
+ ret = hid_register_driver(&elo_driver);
+ if (ret)
+ destroy_workqueue(wq);
+
+ return ret;
}
module_init(elo_driver_init);
static void __exit elo_driver_exit(void)
{
hid_unregister_driver(&elo_driver);
+ destroy_workqueue(wq);
}
module_exit(elo_driver_exit);