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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | /* * Backlight driver for Maxim MAX8925 * * Copyright (C) 2009 Marvell International Ltd. * Haojian Zhuang <haojian.zhuang@marvell.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/init.h> #include <linux/kernel.h> #include <linux/platform_device.h> #include <linux/fb.h> #include <linux/i2c.h> #include <linux/backlight.h> #include <linux/mfd/max8925.h> #include <linux/slab.h> #include <linux/module.h> #define MAX_BRIGHTNESS (0xff) #define MIN_BRIGHTNESS (0) #define LWX_FREQ(x) (((x - 601) / 100) & 0x7) struct max8925_backlight_data { struct max8925_chip *chip; int current_brightness; }; static int max8925_backlight_set(struct backlight_device *bl, int brightness) { struct max8925_backlight_data *data = bl_get_data(bl); struct max8925_chip *chip = data->chip; unsigned char value; int ret; if (brightness > MAX_BRIGHTNESS) value = MAX_BRIGHTNESS; else value = brightness; ret = max8925_reg_write(chip->i2c, MAX8925_WLED_CNTL, value); if (ret < 0) goto out; if (!data->current_brightness && brightness) /* enable WLED output */ ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 1); else if (!brightness) /* disable WLED output */ ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 1, 0); if (ret < 0) goto out; dev_dbg(chip->dev, "set brightness %d\n", value); data->current_brightness = value; return 0; out: dev_dbg(chip->dev, "set brightness %d failure with return value:%d\n", value, ret); return ret; } static int max8925_backlight_update_status(struct backlight_device *bl) { int brightness = bl->props.brightness; if (bl->props.power != FB_BLANK_UNBLANK) brightness = 0; if (bl->props.fb_blank != FB_BLANK_UNBLANK) brightness = 0; if (bl->props.state & BL_CORE_SUSPENDED) brightness = 0; return max8925_backlight_set(bl, brightness); } static int max8925_backlight_get_brightness(struct backlight_device *bl) { struct max8925_backlight_data *data = bl_get_data(bl); struct max8925_chip *chip = data->chip; int ret; ret = max8925_reg_read(chip->i2c, MAX8925_WLED_CNTL); if (ret < 0) return -EINVAL; data->current_brightness = ret; dev_dbg(chip->dev, "get brightness %d\n", data->current_brightness); return ret; } static const struct backlight_ops max8925_backlight_ops = { .options = BL_CORE_SUSPENDRESUME, .update_status = max8925_backlight_update_status, .get_brightness = max8925_backlight_get_brightness, }; static int __devinit max8925_backlight_probe(struct platform_device *pdev) { struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); struct max8925_platform_data *max8925_pdata; struct max8925_backlight_pdata *pdata = NULL; struct max8925_backlight_data *data; struct backlight_device *bl; struct backlight_properties props; struct resource *res; char name[MAX8925_NAME_SIZE]; unsigned char value; int ret; res = platform_get_resource(pdev, IORESOURCE_IO, 0); if (res == NULL) { dev_err(&pdev->dev, "No I/O resource!\n"); return -EINVAL; } if (pdev->dev.parent->platform_data) { max8925_pdata = pdev->dev.parent->platform_data; pdata = max8925_pdata->backlight; } if (!pdata) { dev_err(&pdev->dev, "platform data isn't assigned to " "backlight\n"); return -EINVAL; } data = kzalloc(sizeof(struct max8925_backlight_data), GFP_KERNEL); if (data == NULL) return -ENOMEM; strncpy(name, res->name, MAX8925_NAME_SIZE); data->chip = chip; data->current_brightness = 0; memset(&props, 0, sizeof(struct backlight_properties)); props.type = BACKLIGHT_RAW; props.max_brightness = MAX_BRIGHTNESS; bl = backlight_device_register(name, &pdev->dev, data, &max8925_backlight_ops, &props); if (IS_ERR(bl)) { dev_err(&pdev->dev, "failed to register backlight\n"); kfree(data); return PTR_ERR(bl); } bl->props.brightness = MAX_BRIGHTNESS; platform_set_drvdata(pdev, bl); value = 0; if (pdata->lxw_scl) value |= (1 << 7); if (pdata->lxw_freq) value |= (LWX_FREQ(pdata->lxw_freq) << 4); if (pdata->dual_string) value |= (1 << 1); ret = max8925_set_bits(chip->i2c, MAX8925_WLED_MODE_CNTL, 0xfe, value); if (ret < 0) goto out; backlight_update_status(bl); return 0; out: backlight_device_unregister(bl); kfree(data); return ret; } static int __devexit max8925_backlight_remove(struct platform_device *pdev) { struct backlight_device *bl = platform_get_drvdata(pdev); struct max8925_backlight_data *data = bl_get_data(bl); backlight_device_unregister(bl); kfree(data); return 0; } static struct platform_driver max8925_backlight_driver = { .driver = { .name = "max8925-backlight", .owner = THIS_MODULE, }, .probe = max8925_backlight_probe, .remove = __devexit_p(max8925_backlight_remove), }; static int __init max8925_backlight_init(void) { return platform_driver_register(&max8925_backlight_driver); } module_init(max8925_backlight_init); static void __exit max8925_backlight_exit(void) { platform_driver_unregister(&max8925_backlight_driver); }; module_exit(max8925_backlight_exit); MODULE_DESCRIPTION("Backlight Driver for Maxim MAX8925"); MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:max8925-backlight"); |