1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Backlight driver for Dialog Semiconductor DA9030/DA9034 4 * 5 * Copyright (C) 2008 Compulab, Ltd. 6 * Mike Rapoport <mike@compulab.co.il> 7 * 8 * Copyright (C) 2006-2008 Marvell International Ltd. 9 * Eric Miao <eric.miao@marvell.com> 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/init.h> 14 #include <linux/platform_device.h> 15 #include <linux/fb.h> 16 #include <linux/backlight.h> 17 #include <linux/mfd/da903x.h> 18 #include <linux/slab.h> 19 #include <linux/module.h> 20 21 #define DA9030_WLED_CONTROL 0x25 22 #define DA9030_WLED_CP_EN (1 << 6) 23 #define DA9030_WLED_TRIM(x) ((x) & 0x7) 24 25 #define DA9034_WLED_CONTROL1 0x3C 26 #define DA9034_WLED_CONTROL2 0x3D 27 #define DA9034_WLED_ISET(x) ((x) & 0x1f) 28 29 #define DA9034_WLED_BOOST_EN (1 << 5) 30 31 #define DA9030_MAX_BRIGHTNESS 7 32 #define DA9034_MAX_BRIGHTNESS 0x7f 33 34 struct da903x_backlight_data { 35 struct device *da903x_dev; 36 int id; 37 int current_brightness; 38 }; 39 40 static int da903x_backlight_set(struct backlight_device *bl, int brightness) 41 { 42 struct da903x_backlight_data *data = bl_get_data(bl); 43 struct device *dev = data->da903x_dev; 44 uint8_t val; 45 int ret = 0; 46 47 switch (data->id) { 48 case DA9034_ID_WLED: 49 ret = da903x_update(dev, DA9034_WLED_CONTROL1, 50 brightness, 0x7f); 51 if (ret) 52 return ret; 53 54 if (data->current_brightness && brightness == 0) 55 ret = da903x_clr_bits(dev, 56 DA9034_WLED_CONTROL2, 57 DA9034_WLED_BOOST_EN); 58 59 if (data->current_brightness == 0 && brightness) 60 ret = da903x_set_bits(dev, 61 DA9034_WLED_CONTROL2, 62 DA9034_WLED_BOOST_EN); 63 break; 64 case DA9030_ID_WLED: 65 val = DA9030_WLED_TRIM(brightness); 66 val |= brightness ? DA9030_WLED_CP_EN : 0; 67 ret = da903x_write(dev, DA9030_WLED_CONTROL, val); 68 break; 69 } 70 71 if (ret) 72 return ret; 73 74 data->current_brightness = brightness; 75 return 0; 76 } 77 78 static int da903x_backlight_update_status(struct backlight_device *bl) 79 { 80 return da903x_backlight_set(bl, backlight_get_brightness(bl)); 81 } 82 83 static int da903x_backlight_get_brightness(struct backlight_device *bl) 84 { 85 struct da903x_backlight_data *data = bl_get_data(bl); 86 87 return data->current_brightness; 88 } 89 90 static const struct backlight_ops da903x_backlight_ops = { 91 .options = BL_CORE_SUSPENDRESUME, 92 .update_status = da903x_backlight_update_status, 93 .get_brightness = da903x_backlight_get_brightness, 94 }; 95 96 static int da903x_backlight_probe(struct platform_device *pdev) 97 { 98 struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev); 99 struct da903x_backlight_data *data; 100 struct backlight_device *bl; 101 struct backlight_properties props; 102 int max_brightness; 103 104 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 105 if (data == NULL) 106 return -ENOMEM; 107 108 switch (pdev->id) { 109 case DA9030_ID_WLED: 110 max_brightness = DA9030_MAX_BRIGHTNESS; 111 break; 112 case DA9034_ID_WLED: 113 max_brightness = DA9034_MAX_BRIGHTNESS; 114 break; 115 default: 116 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n", 117 pdev->id); 118 return -EINVAL; 119 } 120 121 data->id = pdev->id; 122 data->da903x_dev = pdev->dev.parent; 123 data->current_brightness = 0; 124 125 /* adjust the WLED output current */ 126 if (pdata) 127 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2, 128 DA9034_WLED_ISET(pdata->output_current)); 129 130 memset(&props, 0, sizeof(props)); 131 props.type = BACKLIGHT_RAW; 132 props.max_brightness = max_brightness; 133 bl = devm_backlight_device_register(&pdev->dev, pdev->name, 134 data->da903x_dev, data, 135 &da903x_backlight_ops, &props); 136 if (IS_ERR(bl)) { 137 dev_err(&pdev->dev, "failed to register backlight\n"); 138 return PTR_ERR(bl); 139 } 140 141 bl->props.brightness = max_brightness; 142 143 platform_set_drvdata(pdev, bl); 144 backlight_update_status(bl); 145 return 0; 146 } 147 148 static struct platform_driver da903x_backlight_driver = { 149 .driver = { 150 .name = "da903x-backlight", 151 }, 152 .probe = da903x_backlight_probe, 153 }; 154 155 module_platform_driver(da903x_backlight_driver); 156 157 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034"); 158 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"); 159 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); 160 MODULE_LICENSE("GPL"); 161 MODULE_ALIAS("platform:da903x-backlight"); 162