1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/video/backlight/jornada720_bl.c b/drivers/video/backlight/jornada720_bl.c
new file mode 100644
index 000000000..996f7ba3b
--- /dev/null
+++ b/drivers/video/backlight/jornada720_bl.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ * Backlight driver for HP Jornada 700 series (710/720/728)
+ * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
+ */
+
+#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;
+	}
+
+	/* 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 (backlight_is_blank(bd)) {
+		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 = devm_backlight_device_register(&pdev->dev, 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 struct platform_driver jornada_bl_driver = {
+	.probe		= jornada_bl_probe,
+	.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");