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2023-12-08 01573e231f18eb2d99162747186f59511f56b64d 
 kernel/drivers/video/backlight/gpio_backlight.c
....@@ -1,44 +1,31 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  * gpio_backlight.c - Simple GPIO-controlled backlight
3
- *
4
- * This program is free software; you can redistribute it and/or modify
5
- * it under the terms of the GNU General Public License version 2 as
6
- * published by the Free Software Foundation.
74  */
85 
96 #include <linux/backlight.h>
107 #include <linux/err.h>
118 #include <linux/fb.h>
12
-#include <linux/gpio.h> /* Only for legacy support */
139 #include <linux/gpio/consumer.h>
1410 #include <linux/init.h>
1511 #include <linux/kernel.h>
1612 #include <linux/module.h>
1713 #include <linux/of.h>
18
-#include <linux/of_gpio.h>
1914 #include <linux/platform_data/gpio_backlight.h>
2015 #include <linux/platform_device.h>
16
+#include <linux/property.h>
2117 #include <linux/slab.h>
2218 
2319 struct gpio_backlight {
24
-	struct device *dev;
2520 	struct device *fbdev;
26
-
2721 	struct gpio_desc *gpiod;
28
-	int def_value;
2922 };
3023 
3124 static int gpio_backlight_update_status(struct backlight_device *bl)
3225 {
3326 	struct gpio_backlight *gbl = bl_get_data(bl);
34
-	int brightness = bl->props.brightness;
3527 
36
-	if (bl->props.power != FB_BLANK_UNBLANK ||
37
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
38
-	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
39
-		brightness = 0;
40
-
41
-	gpiod_set_value_cansleep(gbl->gpiod, brightness);
28
+	gpiod_set_value_cansleep(gbl->gpiod, backlight_get_brightness(bl));
4229 
4330 	return 0;
4431 }
....@@ -57,127 +44,79 @@
5744 	.check_fb	= gpio_backlight_check_fb,
5845 };
5946 
60
-static int gpio_backlight_probe_dt(struct platform_device *pdev,
61
-				   struct gpio_backlight *gbl)
47
+static int gpio_backlight_probe(struct platform_device *pdev)
6248 {
6349 	struct device *dev = &pdev->dev;
64
-	struct device_node *np = dev->of_node;
65
-	int ret;
50
+	struct gpio_backlight_platform_data *pdata = dev_get_platdata(dev);
51
+	struct device_node *of_node = dev->of_node;
52
+	struct backlight_properties props;
53
+	struct backlight_device *bl;
54
+	struct gpio_backlight *gbl;
55
+	int ret, init_brightness, def_value;
6656 
67
-	gbl->def_value = of_property_read_bool(np, "default-on");
57
+	gbl = devm_kzalloc(dev, sizeof(*gbl), GFP_KERNEL);
58
+	if (gbl == NULL)
59
+		return -ENOMEM;
60
+
61
+	if (pdata)
62
+		gbl->fbdev = pdata->fbdev;
63
+
64
+	def_value = device_property_read_bool(dev, "default-on");
6865 
6966 	gbl->gpiod = devm_gpiod_get(dev, NULL, GPIOD_ASIS);
7067 	if (IS_ERR(gbl->gpiod)) {
7168 		ret = PTR_ERR(gbl->gpiod);
72
-
73
-		if (ret != -EPROBE_DEFER) {
69
+		if (ret != -EPROBE_DEFER)
7470 			dev_err(dev,
7571 				"Error: The gpios parameter is missing or invalid.\n");
76
-		}
7772 		return ret;
78
-	}
79
-
80
-	return 0;
81
-}
82
-
83
-static int gpio_backlight_initial_power_state(struct gpio_backlight *gbl)
84
-{
85
-	struct device_node *node = gbl->dev->of_node;
86
-
87
-	/* Not booted with device tree or no phandle link to the node */
88
-	if (!node || !node->phandle)
89
-		return gbl->def_value ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
90
-
91
-	/* if the enable GPIO is disabled, do not enable the backlight */
92
-	if (gpiod_get_value_cansleep(gbl->gpiod) == 0)
93
-		return FB_BLANK_POWERDOWN;
94
-
95
-	return FB_BLANK_UNBLANK;
96
-}
97
-
98
-
99
-static int gpio_backlight_probe(struct platform_device *pdev)
100
-{
101
-	struct gpio_backlight_platform_data *pdata =
102
-		dev_get_platdata(&pdev->dev);
103
-	struct backlight_properties props;
104
-	struct backlight_device *bl;
105
-	struct gpio_backlight *gbl;
106
-	struct device_node *np = pdev->dev.of_node;
107
-	int ret;
108
-
109
-	if (!pdata && !np) {
110
-		dev_err(&pdev->dev,
111
-			"failed to find platform data or device tree node.\n");
112
-		return -ENODEV;
113
-	}
114
-
115
-	gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL);
116
-	if (gbl == NULL)
117
-		return -ENOMEM;
118
-
119
-	gbl->dev = &pdev->dev;
120
-
121
-	if (np) {
122
-		ret = gpio_backlight_probe_dt(pdev, gbl);
123
-		if (ret)
124
-			return ret;
125
-	} else {
126
-		/*
127
-		 * Legacy platform data GPIO retrieveal. Do not expand
128
-		 * the use of this code path, currently only used by one
129
-		 * SH board.
130
-		 */
131
-		unsigned long flags = GPIOF_DIR_OUT;
132
-
133
-		gbl->fbdev = pdata->fbdev;
134
-		gbl->def_value = pdata->def_value;
135
-		flags |= gbl->def_value ? GPIOF_INIT_HIGH : GPIOF_INIT_LOW;
136
-
137
-		ret = devm_gpio_request_one(gbl->dev, pdata->gpio, flags,
138
-					    pdata ? pdata->name : "backlight");
139
-		if (ret < 0) {
140
-			dev_err(&pdev->dev, "unable to request GPIO\n");
141
-			return ret;
142
-		}
143
-		gbl->gpiod = gpio_to_desc(pdata->gpio);
144
-		if (!gbl->gpiod)
145
-			return -EINVAL;
14673 	}
14774 
14875 	memset(&props, 0, sizeof(props));
14976 	props.type = BACKLIGHT_RAW;
15077 	props.max_brightness = 1;
151
-	bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
152
-					&pdev->dev, gbl, &gpio_backlight_ops,
153
-					&props);
78
+	bl = devm_backlight_device_register(dev, dev_name(dev), dev, gbl,
79
+					    &gpio_backlight_ops, &props);
15480 	if (IS_ERR(bl)) {
155
-		dev_err(&pdev->dev, "failed to register backlight\n");
81
+		dev_err(dev, "failed to register backlight\n");
15682 		return PTR_ERR(bl);
15783 	}
15884 
159
-	bl->props.power = gpio_backlight_initial_power_state(gbl);
85
+	/* Set the initial power state */
86
+	if (!of_node || !of_node->phandle)
87
+		/* Not booted with device tree or no phandle link to the node */
88
+		bl->props.power = def_value ? FB_BLANK_UNBLANK
89
+					    : FB_BLANK_POWERDOWN;
90
+	else if (gpiod_get_direction(gbl->gpiod) == 0 &&
91
+		 gpiod_get_value_cansleep(gbl->gpiod) == 0)
92
+		bl->props.power = FB_BLANK_POWERDOWN;
93
+	else
94
+		bl->props.power = FB_BLANK_UNBLANK;
95
+
16096 	bl->props.brightness = 1;
16197 
162
-	backlight_update_status(bl);
98
+	init_brightness = backlight_get_brightness(bl);
99
+	ret = gpiod_direction_output(gbl->gpiod, init_brightness);
100
+	if (ret) {
101
+		dev_err(dev, "failed to set initial brightness\n");
102
+		return ret;
103
+	}
163104 
164105 	platform_set_drvdata(pdev, bl);
165106 	return 0;
166107 }
167108 
168
-#ifdef CONFIG_OF
169109 static struct of_device_id gpio_backlight_of_match[] = {
170110 	{ .compatible = "gpio-backlight" },
171111 	{ /* sentinel */ }
172112 };
173113 
174114 MODULE_DEVICE_TABLE(of, gpio_backlight_of_match);
175
-#endif
176115 
177116 static struct platform_driver gpio_backlight_driver = {
178117 	.driver		= {
179118 		.name		= "gpio-backlight",
180
-		.of_match_table = of_match_ptr(gpio_backlight_of_match),
119
+		.of_match_table = gpio_backlight_of_match,
181120 	},
182121 	.probe		= gpio_backlight_probe,
183122 };