Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / video / backlight / pcf50633-backlight.c

diff --git a/kernel/drivers/video/backlight/pcf50633-backlight.c b/kernel/drivers/video/backlight/pcf50633-backlight.c
new file mode 100644 (file)
index 0000000..85bd573
--- /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");