summaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/jornada720_bl.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/video/backlight/jornada720_bl.c')
-rw-r--r--drivers/video/backlight/jornada720_bl.c150
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..066d0dc98
--- /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");