1 /* 2 * Backlight Driver for Dialog DA9052 PMICs 3 * 4 * Copyright(c) 2012 Dialog Semiconductor Ltd. 5 * 6 * Author: David Dajun Chen <dchen@diasemi.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 */ 14 15 #include <linux/backlight.h> 16 #include <linux/delay.h> 17 #include <linux/fb.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 21 #include <linux/mfd/da9052/da9052.h> 22 #include <linux/mfd/da9052/reg.h> 23 24 #define DA9052_MAX_BRIGHTNESS 0xFF 25 26 enum { 27 DA9052_WLEDS_OFF, 28 DA9052_WLEDS_ON, 29 }; 30 31 enum { 32 DA9052_TYPE_WLED1, 33 DA9052_TYPE_WLED2, 34 DA9052_TYPE_WLED3, 35 }; 36 37 static const unsigned char wled_bank[] = { 38 DA9052_LED1_CONF_REG, 39 DA9052_LED2_CONF_REG, 40 DA9052_LED3_CONF_REG, 41 }; 42 43 struct da9052_bl { 44 struct da9052 *da9052; 45 uint brightness; 46 uint state; 47 uint led_reg; 48 }; 49 50 static int da9052_adjust_wled_brightness(struct da9052_bl *wleds) 51 { 52 unsigned char boost_en; 53 unsigned char i_sink; 54 int ret; 55 56 boost_en = 0x3F; 57 i_sink = 0xFF; 58 if (wleds->state == DA9052_WLEDS_OFF) { 59 boost_en = 0x00; 60 i_sink = 0x00; 61 } 62 63 ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en); 64 if (ret < 0) 65 return ret; 66 67 ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink); 68 if (ret < 0) 69 return ret; 70 71 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0); 72 if (ret < 0) 73 return ret; 74 75 usleep_range(10000, 11000); 76 77 if (wleds->brightness) { 78 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 79 wleds->brightness); 80 if (ret < 0) 81 return ret; 82 } 83 84 return 0; 85 } 86 87 static int da9052_backlight_update_status(struct backlight_device *bl) 88 { 89 int brightness = bl->props.brightness; 90 struct da9052_bl *wleds = bl_get_data(bl); 91 92 wleds->brightness = brightness; 93 wleds->state = DA9052_WLEDS_ON; 94 95 return da9052_adjust_wled_brightness(wleds); 96 } 97 98 static int da9052_backlight_get_brightness(struct backlight_device *bl) 99 { 100 struct da9052_bl *wleds = bl_get_data(bl); 101 102 return wleds->brightness; 103 } 104 105 static const struct backlight_ops da9052_backlight_ops = { 106 .update_status = da9052_backlight_update_status, 107 .get_brightness = da9052_backlight_get_brightness, 108 }; 109 110 static int da9052_backlight_probe(struct platform_device *pdev) 111 { 112 struct backlight_device *bl; 113 struct backlight_properties props; 114 struct da9052_bl *wleds; 115 116 wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL); 117 if (!wleds) 118 return -ENOMEM; 119 120 wleds->da9052 = dev_get_drvdata(pdev->dev.parent); 121 wleds->brightness = 0; 122 wleds->led_reg = platform_get_device_id(pdev)->driver_data; 123 wleds->state = DA9052_WLEDS_OFF; 124 125 props.type = BACKLIGHT_RAW; 126 props.max_brightness = DA9052_MAX_BRIGHTNESS; 127 128 bl = devm_backlight_device_register(&pdev->dev, pdev->name, 129 wleds->da9052->dev, wleds, 130 &da9052_backlight_ops, &props); 131 if (IS_ERR(bl)) { 132 dev_err(&pdev->dev, "Failed to register backlight\n"); 133 return PTR_ERR(bl); 134 } 135 136 bl->props.max_brightness = DA9052_MAX_BRIGHTNESS; 137 bl->props.brightness = 0; 138 platform_set_drvdata(pdev, bl); 139 140 return da9052_adjust_wled_brightness(wleds); 141 } 142 143 static int da9052_backlight_remove(struct platform_device *pdev) 144 { 145 struct backlight_device *bl = platform_get_drvdata(pdev); 146 struct da9052_bl *wleds = bl_get_data(bl); 147 148 wleds->brightness = 0; 149 wleds->state = DA9052_WLEDS_OFF; 150 da9052_adjust_wled_brightness(wleds); 151 152 return 0; 153 } 154 155 static const struct platform_device_id da9052_wled_ids[] = { 156 { 157 .name = "da9052-wled1", 158 .driver_data = DA9052_TYPE_WLED1, 159 }, 160 { 161 .name = "da9052-wled2", 162 .driver_data = DA9052_TYPE_WLED2, 163 }, 164 { 165 .name = "da9052-wled3", 166 .driver_data = DA9052_TYPE_WLED3, 167 }, 168 { }, 169 }; 170 171 static struct platform_driver da9052_wled_driver = { 172 .probe = da9052_backlight_probe, 173 .remove = da9052_backlight_remove, 174 .id_table = da9052_wled_ids, 175 .driver = { 176 .name = "da9052-wled", 177 }, 178 }; 179 180 module_platform_driver(da9052_wled_driver); 181 182 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>"); 183 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC"); 184 MODULE_LICENSE("GPL"); 185 MODULE_ALIAS("platform:da9052-backlight"); 186