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Commit f1c21761 authored by Bruno Prémont's avatar Bruno Prémont Committed by Jiri Kosina
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HID: add backlight support to PicoLCD device 



Add backlight support to PicoLCD device.

Backlight support depends on backlight class and is only being
compiled if backlight class has been selected.

Signed-off-by: default avatarBruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent b8c21cf6

drivers/hid/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -278,8 +278,8 @@ config HID_PICOLCD 
	  - Keypad

	  - Switching between Firmware and Flash mode

	  - Framebuffer for monochrome 256x64 display

	  - Backlight control    (needs CONFIG_BACKLIGHT_CLASS_DEVICE)

	  Features that are not (yet) supported:

	  - Backlight control

	  - Contrast control

	  - IR

	  - General purpose outputs

drivers/hid/hid-picolcd.c

+114 −1
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 


#include <linux/fb.h>

#include <linux/vmalloc.h>

#include <linux/backlight.h>



#include <linux/seq_file.h>

#include <linux/debugfs.h>
@@ -183,6 +184,11 @@ struct picolcd_data { 
	struct fb_info *fb_info;

	struct fb_deferred_io fb_defio;

#endif /* CONFIG_FB */

#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)

	struct backlight_device *backlight;

	u8 lcd_brightness;

	u8 lcd_power;

#endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */



	/* Housekeeping stuff */

	spinlock_t lock;
@@ -729,7 +735,7 @@ static void picolcd_exit_framebuffer(struct picolcd_data *data) 
	kfree(fb_vbitmap);

}





#define picolcd_fbinfo(d) ((d)->fb_info)

#else

static inline int picolcd_fb_reset(struct picolcd_data *data, int clear)

{
@@ -742,8 +748,107 @@ static inline int picolcd_init_framebuffer(struct picolcd_data *data) 
static void picolcd_exit_framebuffer(struct picolcd_data *data)

{

}

#define picolcd_fbinfo(d) NULL

#endif /* CONFIG_FB */



#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)

/*

 * backlight class device

 */

static int picolcd_get_brightness(struct backlight_device *bdev)

{

	struct picolcd_data *data = bl_get_data(bdev);

	return data->lcd_brightness;

}



static int picolcd_set_brightness(struct backlight_device *bdev)

{

	struct picolcd_data *data = bl_get_data(bdev);

	struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev);

	unsigned long flags;



	if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)

		return -ENODEV;



	data->lcd_brightness = bdev->props.brightness & 0x0ff;

	data->lcd_power      = bdev->props.power;

	spin_lock_irqsave(&data->lock, flags);

	hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0);

	usbhid_submit_report(data->hdev, report, USB_DIR_OUT);

	spin_unlock_irqrestore(&data->lock, flags);

	return 0;

}



static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb)

{

	return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev));

}



static const struct backlight_ops picolcd_blops = {

	.update_status  = picolcd_set_brightness,

	.get_brightness = picolcd_get_brightness,

	.check_fb       = picolcd_check_bl_fb,

};



static int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report)

{

	struct device *dev = &data->hdev->dev;

	struct backlight_device *bdev;

	struct backlight_properties props;

	if (!report)

		return -ENODEV;

	if (report->maxfield != 1 || report->field[0]->report_count != 1 ||

			report->field[0]->report_size != 8) {

		dev_err(dev, "unsupported BRIGHTNESS report");

		return -EINVAL;

	}



	memset(&props, 0, sizeof(props));

	props.max_brightness = 0xff;

	bdev = backlight_device_register(dev_name(dev), dev, data,

			&picolcd_blops, &props);

	if (IS_ERR(bdev)) {

		dev_err(dev, "failed to register backlight\n");

		return PTR_ERR(bdev);

	}

	bdev->props.brightness     = 0xff;

	data->lcd_brightness       = 0xff;

	data->backlight            = bdev;

	picolcd_set_brightness(bdev);

	return 0;

}



static void picolcd_exit_backlight(struct picolcd_data *data)

{

	struct backlight_device *bdev = data->backlight;



	data->backlight = NULL;

	if (bdev)

		backlight_device_unregister(bdev);

}



static inline int picolcd_resume_backlight(struct picolcd_data *data)

{

	if (!data->backlight)

		return 0;

	return picolcd_set_brightness(data->backlight);

}



#else

static inline int picolcd_init_backlight(struct picolcd_data *data,

		struct hid_report *report)

{

	return 0;

}

static inline void picolcd_exit_backlight(struct picolcd_data *data)

{

}

static inline int picolcd_resume_backlight(struct picolcd_data *data)

{

	return 0;

}

#endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */



/*

 * input class device

 */
@@ -879,6 +984,7 @@ static int picolcd_reset(struct hid_device *hdev) 
	if (error)

		return error;



	picolcd_resume_backlight(data);

#if defined(CONFIG_FB) || defined(CONFIG_FB_MODULE)

	if (data->fb_info)

		schedule_delayed_work(&data->fb_info->deferred_work, 0);
@@ -1567,6 +1673,11 @@ static int picolcd_probe_lcd(struct hid_device *hdev, struct picolcd_data *data) 
	if (error)

		goto err;



	/* Setup backlight class device */

	error = picolcd_init_backlight(data, picolcd_out_report(REPORT_BRIGHTNESS, hdev));

	if (error)

		goto err;



#ifdef CONFIG_DEBUG_FS

	report = picolcd_out_report(REPORT_READ_MEMORY, hdev);

	if (report && report->maxfield == 1 && report->field[0]->report_size == 8)
@@ -1576,6 +1687,7 @@ static int picolcd_probe_lcd(struct hid_device *hdev, struct picolcd_data *data) 
#endif

	return 0;

err:

	picolcd_exit_backlight(data);

	picolcd_exit_framebuffer(data);

	picolcd_exit_cir(data);

	picolcd_exit_keys(data);
@@ -1707,6 +1819,7 @@ static void picolcd_remove(struct hid_device *hdev) 
	spin_unlock_irqrestore(&data->lock, flags);



	/* Clean up the framebuffer */

	picolcd_exit_backlight(data);

	picolcd_exit_framebuffer(data);

	/* Cleanup input */

	picolcd_exit_cir(data);