Commit d8e5aec8 authored by Jiri Slaby's avatar Jiri Slaby Committed by Jiri Kosina
Browse files

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: default avatarJiri Slaby <jslaby@suse.cz>
Tested-by: default avatarPetr 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: default avatarJiri Kosina <jkosina@suse.cz>
parent d23efc19

drivers/hid/hid-elo.c

+143 −1
Original line number Diff line number Diff line
@@ -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 @@ static int elo_raw_event(struct hid_device *hdev, struct hid_report *report, 
	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 @@ static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id) 
		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 struct hid_driver elo_driver = { 


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);

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