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 23 #define DA9030_WLED_CONTROL 0x25 24 #define DA9030_WLED_CP_EN (1 << 6) 25 #define DA9030_WLED_TRIM(x) ((x) & 0x7) 26 27 #define DA9034_WLED_CONTROL1 0x3C 28 #define DA9034_WLED_CONTROL2 0x3D 29 #define DA9034_WLED_ISET(x) ((x) & 0x1f) 30 31 #define DA9034_WLED_BOOST_EN (1 << 5) 32 33 #define DA9030_MAX_BRIGHTNESS 7 34 #define DA9034_MAX_BRIGHTNESS 0x7f 35 36 struct da903x_backlight_data { 37 struct device *da903x_dev; 38 int id; 39 int current_brightness; 40 }; 41 42 static int da903x_backlight_set(struct backlight_device *bl, int brightness) 43 { 44 struct da903x_backlight_data *data = bl_get_data(bl); 45 struct device *dev = data->da903x_dev; 46 uint8_t val; 47 int ret = 0; 48 49 switch (data->id) { 50 case DA9034_ID_WLED: 51 ret = da903x_update(dev, DA9034_WLED_CONTROL1, 52 brightness, 0x7f); 53 if (ret) 54 return ret; 55 56 if (data->current_brightness && brightness == 0) 57 ret = da903x_clr_bits(dev, 58 DA9034_WLED_CONTROL2, 59 DA9034_WLED_BOOST_EN); 60 61 if (data->current_brightness == 0 && brightness) 62 ret = da903x_set_bits(dev, 63 DA9034_WLED_CONTROL2, 64 DA9034_WLED_BOOST_EN); 65 break; 66 case DA9030_ID_WLED: 67 val = DA9030_WLED_TRIM(brightness); 68 val |= brightness ? DA9030_WLED_CP_EN : 0; 69 ret = da903x_write(dev, DA9030_WLED_CONTROL, val); 70 break; 71 } 72 73 if (ret) 74 return ret; 75 76 data->current_brightness = brightness; 77 return 0; 78 } 79 80 static int da903x_backlight_update_status(struct backlight_device *bl) 81 { 82 int brightness = bl->props.brightness; 83 84 if (bl->props.power != FB_BLANK_UNBLANK) 85 brightness = 0; 86 87 if (bl->props.fb_blank != FB_BLANK_UNBLANK) 88 brightness = 0; 89 90 return da903x_backlight_set(bl, brightness); 91 } 92 93 static int da903x_backlight_get_brightness(struct backlight_device *bl) 94 { 95 struct da903x_backlight_data *data = bl_get_data(bl); 96 return data->current_brightness; 97 } 98 99 static const struct backlight_ops da903x_backlight_ops = { 100 .update_status = da903x_backlight_update_status, 101 .get_brightness = da903x_backlight_get_brightness, 102 }; 103 104 static int da903x_backlight_probe(struct platform_device *pdev) 105 { 106 struct da9034_backlight_pdata *pdata = pdev->dev.platform_data; 107 struct da903x_backlight_data *data; 108 struct backlight_device *bl; 109 struct backlight_properties props; 110 int max_brightness; 111 112 data = kzalloc(sizeof(*data), GFP_KERNEL); 113 if (data == NULL) 114 return -ENOMEM; 115 116 switch (pdev->id) { 117 case DA9030_ID_WLED: 118 max_brightness = DA9030_MAX_BRIGHTNESS; 119 break; 120 case DA9034_ID_WLED: 121 max_brightness = DA9034_MAX_BRIGHTNESS; 122 break; 123 default: 124 dev_err(&pdev->dev, "invalid backlight device ID(%d)\n", 125 pdev->id); 126 kfree(data); 127 return -EINVAL; 128 } 129 130 data->id = pdev->id; 131 data->da903x_dev = pdev->dev.parent; 132 data->current_brightness = 0; 133 134 /* adjust the WLED output current */ 135 if (pdata) 136 da903x_write(data->da903x_dev, DA9034_WLED_CONTROL2, 137 DA9034_WLED_ISET(pdata->output_current)); 138 139 props.max_brightness = max_brightness; 140 bl = backlight_device_register(pdev->name, data->da903x_dev, data, 141 &da903x_backlight_ops, &props); 142 if (IS_ERR(bl)) { 143 dev_err(&pdev->dev, "failed to register backlight\n"); 144 kfree(data); 145 return PTR_ERR(bl); 146 } 147 148 bl->props.brightness = max_brightness; 149 150 platform_set_drvdata(pdev, bl); 151 backlight_update_status(bl); 152 return 0; 153 } 154 155 static int da903x_backlight_remove(struct platform_device *pdev) 156 { 157 struct backlight_device *bl = platform_get_drvdata(pdev); 158 struct da903x_backlight_data *data = bl_get_data(bl); 159 160 backlight_device_unregister(bl); 161 kfree(data); 162 return 0; 163 } 164 165 #ifdef CONFIG_PM 166 static int da903x_backlight_suspend(struct device *dev) 167 { 168 struct platform_device *pdev = to_platform_device(dev); 169 struct backlight_device *bl = platform_get_drvdata(pdev); 170 return da903x_backlight_set(bl, 0); 171 } 172 173 static int da903x_backlight_resume(struct device *dev) 174 { 175 struct platform_device *pdev = to_platform_device(dev); 176 struct backlight_device *bl = platform_get_drvdata(pdev); 177 178 backlight_update_status(bl); 179 return 0; 180 } 181 182 static const struct dev_pm_ops da903x_backlight_pm_ops = { 183 .suspend = da903x_backlight_suspend, 184 .resume = da903x_backlight_resume, 185 }; 186 #endif 187 188 static struct platform_driver da903x_backlight_driver = { 189 .driver = { 190 .name = "da903x-backlight", 191 .owner = THIS_MODULE, 192 #ifdef CONFIG_PM 193 .pm = &da903x_backlight_pm_ops, 194 #endif 195 }, 196 .probe = da903x_backlight_probe, 197 .remove = da903x_backlight_remove, 198 }; 199 200 static int __init da903x_backlight_init(void) 201 { 202 return platform_driver_register(&da903x_backlight_driver); 203 } 204 module_init(da903x_backlight_init); 205 206 static void __exit da903x_backlight_exit(void) 207 { 208 platform_driver_unregister(&da903x_backlight_driver); 209 } 210 module_exit(da903x_backlight_exit); 211 212 MODULE_DESCRIPTION("Backlight Driver for Dialog Semiconductor DA9030/DA9034"); 213 MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>" 214 "Mike Rapoport <mike@compulab.co.il>"); 215 MODULE_LICENSE("GPL"); 216 MODULE_ALIAS("platform:da903x-backlight"); 217