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path: root/drivers/video/backlight/rave-sp-backlight.c
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Diffstat (limited to 'drivers/video/backlight/rave-sp-backlight.c')
-rw-r--r--drivers/video/backlight/rave-sp-backlight.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/drivers/video/backlight/rave-sp-backlight.c b/drivers/video/backlight/rave-sp-backlight.c
new file mode 100644
index 000000000..05b5f003a
--- /dev/null
+++ b/drivers/video/backlight/rave-sp-backlight.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * LCD Backlight driver for RAVE SP
+ *
+ * Copyright (C) 2018 Zodiac Inflight Innovations
+ *
+ */
+
+#include <linux/backlight.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/rave-sp.h>
+#include <linux/platform_device.h>
+
+#define RAVE_SP_BACKLIGHT_LCD_EN BIT(7)
+
+static int rave_sp_backlight_update_status(struct backlight_device *bd)
+{
+ const struct backlight_properties *p = &bd->props;
+ const u8 intensity =
+ (p->power == FB_BLANK_UNBLANK) ? p->brightness : 0;
+ struct rave_sp *sp = dev_get_drvdata(&bd->dev);
+ u8 cmd[] = {
+ [0] = RAVE_SP_CMD_SET_BACKLIGHT,
+ [1] = 0,
+ [2] = intensity ? RAVE_SP_BACKLIGHT_LCD_EN | intensity : 0,
+ [3] = 0,
+ [4] = 0,
+ };
+
+ return rave_sp_exec(sp, cmd, sizeof(cmd), NULL, 0);
+}
+
+static const struct backlight_ops rave_sp_backlight_ops = {
+ .options = BL_CORE_SUSPENDRESUME,
+ .update_status = rave_sp_backlight_update_status,
+};
+
+static struct backlight_properties rave_sp_backlight_props = {
+ .type = BACKLIGHT_PLATFORM,
+ .max_brightness = 100,
+ .brightness = 50,
+};
+
+static int rave_sp_backlight_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct backlight_device *bd;
+
+ bd = devm_backlight_device_register(dev, pdev->name, dev,
+ dev_get_drvdata(dev->parent),
+ &rave_sp_backlight_ops,
+ &rave_sp_backlight_props);
+ if (IS_ERR(bd))
+ return PTR_ERR(bd);
+
+ /*
+ * If there is a phandle pointing to the device node we can
+ * assume that another device will manage the status changes.
+ * If not we make sure the backlight is in a consistent state.
+ */
+ if (!dev->of_node->phandle)
+ backlight_update_status(bd);
+
+ return 0;
+}
+
+static const struct of_device_id rave_sp_backlight_of_match[] = {
+ { .compatible = "zii,rave-sp-backlight" },
+ {}
+};
+
+static struct platform_driver rave_sp_backlight_driver = {
+ .probe = rave_sp_backlight_probe,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = rave_sp_backlight_of_match,
+ },
+};
+module_platform_driver(rave_sp_backlight_driver);
+
+MODULE_DEVICE_TABLE(of, rave_sp_backlight_of_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
+MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
+MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
+MODULE_DESCRIPTION("RAVE SP Backlight driver");