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