Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/drivers/video/backlight/max8925_bl.c b/drivers/video/backlight/max8925_bl.c
new file mode 100644
index 000000000..f3aa6088f
--- /dev/null
+++ b/drivers/video/backlight/max8925_bl.c
@@ -0,0 +1,211 @@
+/*
+ * Backlight driver for Maxim MAX8925
+ *
+ * Copyright (C) 2009 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.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 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/backlight.h>
+#include <linux/mfd/max8925.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#define MAX_BRIGHTNESS		(0xff)
+#define MIN_BRIGHTNESS		(0)
+
+#define LWX_FREQ(x)		(((x - 601) / 100) & 0x7)
+
+struct max8925_backlight_data {
+	struct max8925_chip	*chip;
+
+	int	current_brightness;
+	int	reg_mode_cntl;
+	int	reg_cntl;
+};
+
+static int max8925_backlight_set(struct backlight_device *bl, int brightness)
+{
+	struct max8925_backlight_data *data = bl_get_data(bl);
+	struct max8925_chip *chip = data->chip;
+	unsigned char value;
+	int ret;
+
+	if (brightness > MAX_BRIGHTNESS)
+		value = MAX_BRIGHTNESS;
+	else
+		value = brightness;
+
+	ret = max8925_reg_write(chip->i2c, data->reg_cntl, value);
+	if (ret < 0)
+		goto out;
+
+	if (!data->current_brightness && brightness)
+		/* enable WLED output */
+		ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 1);
+	else if (!brightness)
+		/* disable WLED output */
+		ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 1, 0);
+	if (ret < 0)
+		goto out;
+	dev_dbg(chip->dev, "set brightness %d\n", value);
+	data->current_brightness = value;
+	return 0;
+out:
+	dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n",
+		value, ret);
+	return ret;
+}
+
+static int max8925_backlight_update_status(struct backlight_device *bl)
+{
+	int brightness = bl->props.brightness;
+
+	if (bl->props.power != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bl->props.state & BL_CORE_SUSPENDED)
+		brightness = 0;
+
+	return max8925_backlight_set(bl, brightness);
+}
+
+static int max8925_backlight_get_brightness(struct backlight_device *bl)
+{
+	struct max8925_backlight_data *data = bl_get_data(bl);
+	struct max8925_chip *chip = data->chip;
+	int ret;
+
+	ret = max8925_reg_read(chip->i2c, data->reg_cntl);
+	if (ret < 0)
+		return -EINVAL;
+	data->current_brightness = ret;
+	dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness);
+	return ret;
+}
+
+static const struct backlight_ops max8925_backlight_ops = {
+	.options	= BL_CORE_SUSPENDRESUME,
+	.update_status	= max8925_backlight_update_status,
+	.get_brightness	= max8925_backlight_get_brightness,
+};
+
+static void max8925_backlight_dt_init(struct platform_device *pdev)
+{
+	struct device_node *nproot = pdev->dev.parent->of_node, *np;
+	struct max8925_backlight_pdata *pdata;
+	u32 val;
+
+	if (!nproot || !IS_ENABLED(CONFIG_OF))
+		return;
+
+	pdata = devm_kzalloc(&pdev->dev,
+			     sizeof(struct max8925_backlight_pdata),
+			     GFP_KERNEL);
+	if (!pdata)
+		return;
+
+	np = of_get_child_by_name(nproot, "backlight");
+	if (!np) {
+		dev_err(&pdev->dev, "failed to find backlight node\n");
+		return;
+	}
+
+	if (!of_property_read_u32(np, "maxim,max8925-dual-string", &val))
+		pdata->dual_string = val;
+
+	of_node_put(np);
+
+	pdev->dev.platform_data = pdata;
+}
+
+static int max8925_backlight_probe(struct platform_device *pdev)
+{
+	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
+	struct max8925_backlight_pdata *pdata;
+	struct max8925_backlight_data *data;
+	struct backlight_device *bl;
+	struct backlight_properties props;
+	struct resource *res;
+	unsigned char value;
+	int ret = 0;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct max8925_backlight_data),
+			    GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "No REG resource for mode control!\n");
+		return -ENXIO;
+	}
+	data->reg_mode_cntl = res->start;
+	res = platform_get_resource(pdev, IORESOURCE_REG, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "No REG resource for control!\n");
+		return -ENXIO;
+	}
+	data->reg_cntl = res->start;
+
+	data->chip = chip;
+	data->current_brightness = 0;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = MAX_BRIGHTNESS;
+	bl = devm_backlight_device_register(&pdev->dev, "max8925-backlight",
+					&pdev->dev, data,
+					&max8925_backlight_ops, &props);
+	if (IS_ERR(bl)) {
+		dev_err(&pdev->dev, "failed to register backlight\n");
+		return PTR_ERR(bl);
+	}
+	bl->props.brightness = MAX_BRIGHTNESS;
+
+	platform_set_drvdata(pdev, bl);
+
+	value = 0;
+	if (!pdev->dev.platform_data)
+		max8925_backlight_dt_init(pdev);
+
+	pdata = pdev->dev.platform_data;
+	if (pdata) {
+		if (pdata->lxw_scl)
+			value |= (1 << 7);
+		if (pdata->lxw_freq)
+			value |= (LWX_FREQ(pdata->lxw_freq) << 4);
+		if (pdata->dual_string)
+			value |= (1 << 1);
+	}
+	ret = max8925_set_bits(chip->i2c, data->reg_mode_cntl, 0xfe, value);
+	if (ret < 0)
+		return ret;
+	backlight_update_status(bl);
+	return 0;
+}
+
+static struct platform_driver max8925_backlight_driver = {
+	.driver		= {
+		.name	= "max8925-backlight",
+	},
+	.probe		= max8925_backlight_probe,
+};
+
+module_platform_driver(max8925_backlight_driver);
+
+MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:max8925-backlight");