X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fvideo%2Fbacklight%2Fpcf50633-backlight.c;fp=kernel%2Fdrivers%2Fvideo%2Fbacklight%2Fpcf50633-backlight.c;h=85bd573b6d15c1b248fefb9addc5fd755772b635;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/video/backlight/pcf50633-backlight.c b/kernel/drivers/video/backlight/pcf50633-backlight.c
new file mode 100644
index 000000000..85bd573b6
--- /dev/null
+++ b/kernel/drivers/video/backlight/pcf50633-backlight.c
@@ -0,0 +1,164 @@
+/*
+ *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ *      PCF50633 backlight device driver
+ *
+ *  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;  either version 2 of the	License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include <linux/backlight.h>
+#include <linux/fb.h>
+
+#include <linux/mfd/pcf50633/core.h>
+#include <linux/mfd/pcf50633/backlight.h>
+
+struct pcf50633_bl {
+	struct pcf50633 *pcf;
+	struct backlight_device *bl;
+
+	unsigned int brightness;
+	unsigned int brightness_limit;
+};
+
+/*
+ * pcf50633_bl_set_brightness_limit
+ *
+ * Update the brightness limit for the pc50633 backlight. The actual brightness
+ * will not go above the limit. This is useful to limit power drain for example
+ * on low battery.
+ *
+ * @dev: Pointer to a pcf50633 device
+ * @limit: The brightness limit. Valid values are 0-63
+ */
+int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit)
+{
+	struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev);
+
+	if (!pcf_bl)
+		return -ENODEV;
+
+	pcf_bl->brightness_limit = limit & 0x3f;
+	backlight_update_status(pcf_bl->bl);
+
+	return 0;
+}
+
+static int pcf50633_bl_update_status(struct backlight_device *bl)
+{
+	struct pcf50633_bl *pcf_bl = bl_get_data(bl);
+	unsigned int new_brightness;
+
+
+	if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK) ||
+		bl->props.power != FB_BLANK_UNBLANK)
+		new_brightness = 0;
+	else if (bl->props.brightness < pcf_bl->brightness_limit)
+		new_brightness = bl->props.brightness;
+	else
+		new_brightness = pcf_bl->brightness_limit;
+
+
+	if (pcf_bl->brightness == new_brightness)
+		return 0;
+
+	if (new_brightness) {
+		pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDOUT,
+					new_brightness);
+		if (!pcf_bl->brightness)
+			pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 1);
+	} else {
+		pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 0);
+	}
+
+	pcf_bl->brightness = new_brightness;
+
+	return 0;
+}
+
+static int pcf50633_bl_get_brightness(struct backlight_device *bl)
+{
+	struct pcf50633_bl *pcf_bl = bl_get_data(bl);
+
+	return pcf_bl->brightness;
+}
+
+static const struct backlight_ops pcf50633_bl_ops = {
+	.get_brightness = pcf50633_bl_get_brightness,
+	.update_status	= pcf50633_bl_update_status,
+	.options	= BL_CORE_SUSPENDRESUME,
+};
+
+static int pcf50633_bl_probe(struct platform_device *pdev)
+{
+	struct pcf50633_bl *pcf_bl;
+	struct device *parent = pdev->dev.parent;
+	struct pcf50633_platform_data *pcf50633_data = dev_get_platdata(parent);
+	struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data;
+	struct backlight_properties bl_props;
+
+	pcf_bl = devm_kzalloc(&pdev->dev, sizeof(*pcf_bl), GFP_KERNEL);
+	if (!pcf_bl)
+		return -ENOMEM;
+
+	memset(&bl_props, 0, sizeof(bl_props));
+	bl_props.type = BACKLIGHT_RAW;
+	bl_props.max_brightness = 0x3f;
+	bl_props.power = FB_BLANK_UNBLANK;
+
+	if (pdata) {
+		bl_props.brightness = pdata->default_brightness;
+		pcf_bl->brightness_limit = pdata->default_brightness_limit;
+	} else {
+		bl_props.brightness = 0x3f;
+		pcf_bl->brightness_limit = 0x3f;
+	}
+
+	pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent);
+
+	pcf_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
+						&pdev->dev, pcf_bl,
+						&pcf50633_bl_ops, &bl_props);
+
+	if (IS_ERR(pcf_bl->bl))
+		return PTR_ERR(pcf_bl->bl);
+
+	platform_set_drvdata(pdev, pcf_bl);
+
+	pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time);
+
+	/*
+	 * Should be different from bl_props.brightness, so we do not exit
+	 * update_status early the first time it's called
+	 */
+	pcf_bl->brightness = pcf_bl->bl->props.brightness + 1;
+
+	backlight_update_status(pcf_bl->bl);
+
+	return 0;
+}
+
+static struct platform_driver pcf50633_bl_driver = {
+	.probe =	pcf50633_bl_probe,
+	.driver = {
+		.name = "pcf50633-backlight",
+	},
+};
+
+module_platform_driver(pcf50633_bl_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("PCF50633 backlight driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pcf50633-backlight");