From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 drivers/video/backlight/jornada720_bl.c | 163 ++++++++++++++++++++++++++++++++
 1 file changed, 163 insertions(+)
 create mode 100644 drivers/video/backlight/jornada720_bl.c

(limited to 'drivers/video/backlight/jornada720_bl.c')

diff --git a/drivers/video/backlight/jornada720_bl.c b/drivers/video/backlight/jornada720_bl.c
new file mode 100644
index 00000000..3ccb8934
--- /dev/null
+++ b/drivers/video/backlight/jornada720_bl.c
@@ -0,0 +1,163 @@
+/*
+ *
+ * Backlight driver for HP Jornada 700 series (710/720/728)
+ * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 or any later version as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/backlight.h>
+#include <linux/device.h>
+#include <linux/fb.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <mach/jornada720.h>
+#include <mach/hardware.h>
+
+#include <video/s1d13xxxfb.h>
+
+#define BL_MAX_BRIGHT	255
+#define BL_DEF_BRIGHT	25
+
+static int jornada_bl_get_brightness(struct backlight_device *bd)
+{
+	int ret;
+
+	/* check if backlight is on */
+	if (!(PPSR & PPC_LDD1))
+		return 0;
+
+	jornada_ssp_start();
+
+	/* cmd should return txdummy */
+	ret = jornada_ssp_byte(GETBRIGHTNESS);
+
+	if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
+		dev_err(&bd->dev, "get brightness timeout\n");
+		jornada_ssp_end();
+		return -ETIMEDOUT;
+	} else {
+		/* exchange txdummy for value */
+		ret = jornada_ssp_byte(TXDUMMY);
+	}
+
+	jornada_ssp_end();
+
+	return BL_MAX_BRIGHT - ret;
+}
+
+static int jornada_bl_update_status(struct backlight_device *bd)
+{
+	int ret = 0;
+
+	jornada_ssp_start();
+
+	/* If backlight is off then really turn it off */
+	if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
+		ret = jornada_ssp_byte(BRIGHTNESSOFF);
+		if (ret != TXDUMMY) {
+			dev_info(&bd->dev, "brightness off timeout\n");
+			/* turn off backlight */
+			PPSR &= ~PPC_LDD1;
+			PPDR |= PPC_LDD1;
+			ret = -ETIMEDOUT;
+		}
+	} else  /* turn on backlight */
+		PPSR |= PPC_LDD1;
+
+		/* send command to our mcu */
+		if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
+			dev_info(&bd->dev, "failed to set brightness\n");
+			ret = -ETIMEDOUT;
+			goto out;
+		}
+
+		/*
+		 * at this point we expect that the mcu has accepted
+		 * our command and is waiting for our new value
+		 * please note that maximum brightness is 255,
+		 * but due to physical layout it is equal to 0, so we simply
+		 * invert the value (MAX VALUE - NEW VALUE).
+		 */
+		if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness)
+			!= TXDUMMY) {
+			dev_err(&bd->dev, "set brightness failed\n");
+			ret = -ETIMEDOUT;
+		}
+
+		/*
+		 * If infact we get an TXDUMMY as output we are happy and dont
+		 * make any further comments about it
+		 */
+out:
+	jornada_ssp_end();
+
+	return ret;
+}
+
+static const struct backlight_ops jornada_bl_ops = {
+	.get_brightness = jornada_bl_get_brightness,
+	.update_status = jornada_bl_update_status,
+	.options = BL_CORE_SUSPENDRESUME,
+};
+
+static int jornada_bl_probe(struct platform_device *pdev)
+{
+	struct backlight_properties props;
+	int ret;
+	struct backlight_device *bd;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = BL_MAX_BRIGHT;
+	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL,
+				       &jornada_bl_ops, &props);
+
+	if (IS_ERR(bd)) {
+		ret = PTR_ERR(bd);
+		dev_err(&pdev->dev, "failed to register device, err=%x\n", ret);
+		return ret;
+	}
+
+	bd->props.power = FB_BLANK_UNBLANK;
+	bd->props.brightness = BL_DEF_BRIGHT;
+	/*
+	 * note. make sure max brightness is set otherwise
+	 * you will get seemingly non-related errors when
+	 * trying to change brightness
+	 */
+	jornada_bl_update_status(bd);
+
+	platform_set_drvdata(pdev, bd);
+	dev_info(&pdev->dev, "HP Jornada 700 series backlight driver\n");
+
+	return 0;
+}
+
+static int jornada_bl_remove(struct platform_device *pdev)
+{
+	struct backlight_device *bd = platform_get_drvdata(pdev);
+
+	backlight_device_unregister(bd);
+
+	return 0;
+}
+
+static struct platform_driver jornada_bl_driver = {
+	.probe		= jornada_bl_probe,
+	.remove		= jornada_bl_remove,
+	.driver	= {
+		.name	= "jornada_bl",
+	},
+};
+
+module_platform_driver(jornada_bl_driver);
+
+MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
+MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
+MODULE_LICENSE("GPL");
-- 
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