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