linux/drivers/hid/hid-picolcd_lcd.c
Bruno Prémont a93ab84948 HID: picoLCD: Improve unplug handling
Stop earlier attempting to submit new reports/URBs (though locking and
usbhid still prevents to bail out early enough to not produce multiple
  hid-picolcd 0003:04D8:C002.0003: usb_submit_urb(out) failed: -19
messages in kernel log.

Strengthen framebuffer removal to be less racy.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-08-15 10:13:26 +02:00

108 lines
3.5 KiB
C

/***************************************************************************
* Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *
* *
* Based on Logitech G13 driver (v0.4) *
* Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *
* *
* This program is free software: you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation, version 2 of the License. *
* *
* This driver is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this software. If not see <http://www.gnu.org/licenses/>. *
***************************************************************************/
#include <linux/hid.h>
#include "usbhid/usbhid.h"
#include <linux/usb.h>
#include <linux/fb.h>
#include <linux/lcd.h>
#include "hid-picolcd.h"
/*
* lcd class device
*/
static int picolcd_get_contrast(struct lcd_device *ldev)
{
struct picolcd_data *data = lcd_get_data(ldev);
return data->lcd_contrast;
}
static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
{
struct picolcd_data *data = lcd_get_data(ldev);
struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
unsigned long flags;
if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
return -ENODEV;
data->lcd_contrast = contrast & 0x0ff;
spin_lock_irqsave(&data->lock, flags);
hid_set_field(report->field[0], 0, data->lcd_contrast);
if (!(data->status & PICOLCD_FAILED))
usbhid_submit_report(data->hdev, report, USB_DIR_OUT);
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
{
return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
}
static struct lcd_ops picolcd_lcdops = {
.get_contrast = picolcd_get_contrast,
.set_contrast = picolcd_set_contrast,
.check_fb = picolcd_check_lcd_fb,
};
int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
{
struct device *dev = &data->hdev->dev;
struct lcd_device *ldev;
if (!report)
return -ENODEV;
if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
report->field[0]->report_size != 8) {
dev_err(dev, "unsupported CONTRAST report");
return -EINVAL;
}
ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
if (IS_ERR(ldev)) {
dev_err(dev, "failed to register LCD\n");
return PTR_ERR(ldev);
}
ldev->props.max_contrast = 0x0ff;
data->lcd_contrast = 0xe5;
data->lcd = ldev;
picolcd_set_contrast(ldev, 0xe5);
return 0;
}
void picolcd_exit_lcd(struct picolcd_data *data)
{
struct lcd_device *ldev = data->lcd;
data->lcd = NULL;
if (ldev)
lcd_device_unregister(ldev);
}
int picolcd_resume_lcd(struct picolcd_data *data)
{
if (!data->lcd)
return 0;
return picolcd_set_contrast(data->lcd, data->lcd_contrast);
}