1 /* 2 * Backlight driver for Dialog Semiconductor DA9030/DA9034 3 * 4 * Copyright (C) 2008 Compulab, Ltd. 5 * Mike Rapoport <mike@compulab.co.il> 6 * 7 * Copyright (C) 2006-2008 Marvell International Ltd. 8 * Eric Miao <eric.miao@marvell.com> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/kernel.h> 16 #include <linux/init.h> 17 #include <linux/platform_device.h> 18 #include <linux/fb.h> 19 #include <linux/backlight.h> 20 #include <linux/mfd/da903x.h> 21 #include <linux/slab.h> 22 #include <linux/module.h> 23 24 #define DA9030_WLED_CONTROL 0x25 25 #define DA9030_WLED_CP_EN (1 << 6) 26 #define DA9030_WLED_TRIM(x) ((x) & 0x7) 27 28 #define DA9034_WLED_CONTROL1 0x3C 29 #define DA9034_WLED_CONTROL2 0x3D 30 #define DA9034_WLED_ISET(x) ((x) & 0x1f) 31 32 #define DA9034_WLED_BOOST_EN (1 << 5) 33 34 #define DA9030_MAX_BRIGHTNESS 7 35 #define DA9034_MAX_BRIGHTNESS 0x7f 36 37 struct da903x_backlight_data { 38 struct device *da903x_dev; 39 int id; 40 int current_brightness; 41 }; 42 43 static int da903x_backlight_set(struct backlight_device *bl, int brightness) 44 { 45 struct da903x_backlight_data *data = bl_get_data(bl); 46 struct device *dev = data->da903x_dev; 47 uint8_t val; 48 int ret = 0; 49 50 switch (data->id) { 51 case DA9034_ID_WLED: 52 ret = da903x_update(dev, DA9034_WLED_CONTROL1, 53 brightness, 0x7f); 54 if (ret) 55 return ret; 56 57 if (data->current_brightness && brightness == 0) 58 ret = da903x_clr_bits(dev, 59 DA9034_WLED_CONTROL2, 60 DA9034_WLED_BOOST_EN); 61 62 if (data->current_brightness == 0 && brightness) 63 ret = da903x_set_bits(dev, 64 DA9034_WLED_CONTROL2, 65 DA9034_WLED_BOOST_EN); 66 break; 67 case DA9030_ID_WLED: 68 val = DA9030_WLED_TRIM(brightness); 69 val |= brightness ? DA9030_WLED_CP_EN : 0; 70 ret = da903x_write(dev, DA9030_WLED_CONTROL, val); 71 break; 72 } 73 74 if (ret) 75 return ret; 76 77 data->current_brightness = brightness; 78 return 0; 79 } 80 81 static int da903x_backlight_update_status(struct backlight_device *bl) 82 { 83 int brightness = bl->props.brightness; 84 85 if (bl->props.power != FB_BLANK_UNBLANK) 86 brightness = 0; 87 88 if (bl->props.fb_blank != FB_BLANK_UNBLANK) 89 brightness = 0; 90 91 if (bl->props.state & BL_CORE_SUSPENDED) 92 brightness = 0; 93 94 return da903x_backlight_set(bl, brightness); 95 } 96 97 static int da903x_backlight_get_brightness(struct backlight_device *bl) 98 { 99 struct da903x_backlight_data *data = bl_get_data(bl); 100 101 return data->current_brightness; 102 } 103 104 static const struct backlight_ops da903x_backlight_ops = { 105 .options = BL_CORE_SUSPENDRESUME, 106 .update_status = da903x_backlight_update_status, 107 .get_brightness = da903x_backlight_get_brightness, 108 }; 109 110 static int da903x_backlight_probe(struct platform_device *pdev) 111 { 112 struct da9034_backlight_pdata *pdata = dev_get_platdata(&pdev->dev); 113 struct da903x_backlight_data *data; 114 struct backlight_device *bl; 115 struct backlight_properties props; 116 int max_brightness; 117 118 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 119 if (data == NULL) 120 return -ENOMEM; 121 122 switch (pdev->id) { 123 case DA9030_ID_WLED: 124 max_brightness = DA9030_MAX_BRIGHTNESS; 125 break; 126 case DA9034_ID_WLED: 127 max_brightness = DA9034_MAX_BRIGHTNESS; 128 break; 129 default: 130 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n", 131 pdev->id); 132 return -EINVAL; 133 } 134 135 data->id = pdev->id; 136 data->da903x_dev = pdev->dev.parent; 137 data->current_brightness = 0; 138 139 /* adjust the WLED output current */ 140 if (pdata) 141 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2, 142 DA9034_WLED_ISET(pdata->output_current)); 143 144 memset(&props, 0, sizeof(props)); 145 props.type = BACKLIGHT_RAW; 146 props.max_brightness = max_brightness; 147 bl = devm_backlight_device_register(&pdev->dev, pdev->name, 148 data->da903x_dev, data, 149 &da903x_backlight_ops, &props); 150 if (IS_ERR(bl)) { 151 dev_err(&pdev->dev, "failed to register backlight\n"); 152 return PTR_ERR(bl); 153 } 154 155 bl->props.brightness = max_brightness; 156 157 platform_set_drvdata(pdev, bl); 158 backlight_update_status(bl); 159 return 0; 160 } 161 162 static struct platform_driver da903x_backlight_driver = { 163 .driver = { 164 .name = "da903x-backlight", 165 }, 166 .probe = da903x_backlight_probe, 167 }; 168 169 module_platform_driver(da903x_backlight_driver); 170 171 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034"); 172 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"); 173 MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>"); 174 MODULE_LICENSE("GPL"); 175 MODULE_ALIAS("platform:da903x-backlight"); 176