1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Backlight Driver for Dialog DA9052 PMICs 4 * 5 * Copyright(c) 2012 Dialog Semiconductor Ltd. 6 * 7 * Author: David Dajun Chen <dchen@diasemi.com> 8 */ 9 10 #include <linux/backlight.h> 11 #include <linux/delay.h> 12 #include <linux/fb.h> 13 #include <linux/module.h> 14 #include <linux/platform_device.h> 15 16 #include <linux/mfd/da9052/da9052.h> 17 #include <linux/mfd/da9052/reg.h> 18 19 #define DA9052_MAX_BRIGHTNESS 0xFF 20 21 enum { 22 DA9052_WLEDS_OFF, 23 DA9052_WLEDS_ON, 24 }; 25 26 enum { 27 DA9052_TYPE_WLED1, 28 DA9052_TYPE_WLED2, 29 DA9052_TYPE_WLED3, 30 }; 31 32 static const unsigned char wled_bank[] = { 33 DA9052_LED1_CONF_REG, 34 DA9052_LED2_CONF_REG, 35 DA9052_LED3_CONF_REG, 36 }; 37 38 struct da9052_bl { 39 struct da9052 *da9052; 40 uint brightness; 41 uint state; 42 uint led_reg; 43 }; 44 45 static int da9052_adjust_wled_brightness(struct da9052_bl *wleds) 46 { 47 unsigned char boost_en; 48 unsigned char i_sink; 49 int ret; 50 51 boost_en = 0x3F; 52 i_sink = 0xFF; 53 if (wleds->state == DA9052_WLEDS_OFF) { 54 boost_en = 0x00; 55 i_sink = 0x00; 56 } 57 58 ret = da9052_reg_write(wleds->da9052, DA9052_BOOST_REG, boost_en); 59 if (ret < 0) 60 return ret; 61 62 ret = da9052_reg_write(wleds->da9052, DA9052_LED_CONT_REG, i_sink); 63 if (ret < 0) 64 return ret; 65 66 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 0x0); 67 if (ret < 0) 68 return ret; 69 70 usleep_range(10000, 11000); 71 72 if (wleds->brightness) { 73 ret = da9052_reg_write(wleds->da9052, wled_bank[wleds->led_reg], 74 wleds->brightness); 75 if (ret < 0) 76 return ret; 77 } 78 79 return 0; 80 } 81 82 static int da9052_backlight_update_status(struct backlight_device *bl) 83 { 84 int brightness = bl->props.brightness; 85 struct da9052_bl *wleds = bl_get_data(bl); 86 87 wleds->brightness = brightness; 88 wleds->state = DA9052_WLEDS_ON; 89 90 return da9052_adjust_wled_brightness(wleds); 91 } 92 93 static int da9052_backlight_get_brightness(struct backlight_device *bl) 94 { 95 struct da9052_bl *wleds = bl_get_data(bl); 96 97 return wleds->brightness; 98 } 99 100 static const struct backlight_ops da9052_backlight_ops = { 101 .update_status = da9052_backlight_update_status, 102 .get_brightness = da9052_backlight_get_brightness, 103 }; 104 105 static int da9052_backlight_probe(struct platform_device *pdev) 106 { 107 struct backlight_device *bl; 108 struct backlight_properties props; 109 struct da9052_bl *wleds; 110 111 wleds = devm_kzalloc(&pdev->dev, sizeof(struct da9052_bl), GFP_KERNEL); 112 if (!wleds) 113 return -ENOMEM; 114 115 wleds->da9052 = dev_get_drvdata(pdev->dev.parent); 116 wleds->brightness = 0; 117 wleds->led_reg = platform_get_device_id(pdev)->driver_data; 118 wleds->state = DA9052_WLEDS_OFF; 119 120 props.type = BACKLIGHT_RAW; 121 props.max_brightness = DA9052_MAX_BRIGHTNESS; 122 123 bl = devm_backlight_device_register(&pdev->dev, pdev->name, 124 wleds->da9052->dev, wleds, 125 &da9052_backlight_ops, &props); 126 if (IS_ERR(bl)) { 127 dev_err(&pdev->dev, "Failed to register backlight\n"); 128 return PTR_ERR(bl); 129 } 130 131 bl->props.max_brightness = DA9052_MAX_BRIGHTNESS; 132 bl->props.brightness = 0; 133 platform_set_drvdata(pdev, bl); 134 135 return da9052_adjust_wled_brightness(wleds); 136 } 137 138 static void da9052_backlight_remove(struct platform_device *pdev) 139 { 140 struct backlight_device *bl = platform_get_drvdata(pdev); 141 struct da9052_bl *wleds = bl_get_data(bl); 142 143 wleds->brightness = 0; 144 wleds->state = DA9052_WLEDS_OFF; 145 da9052_adjust_wled_brightness(wleds); 146 } 147 148 static const struct platform_device_id da9052_wled_ids[] = { 149 { 150 .name = "da9052-wled1", 151 .driver_data = DA9052_TYPE_WLED1, 152 }, 153 { 154 .name = "da9052-wled2", 155 .driver_data = DA9052_TYPE_WLED2, 156 }, 157 { 158 .name = "da9052-wled3", 159 .driver_data = DA9052_TYPE_WLED3, 160 }, 161 { }, 162 }; 163 MODULE_DEVICE_TABLE(platform, da9052_wled_ids); 164 165 static struct platform_driver da9052_wled_driver = { 166 .probe = da9052_backlight_probe, 167 .remove_new = da9052_backlight_remove, 168 .id_table = da9052_wled_ids, 169 .driver = { 170 .name = "da9052-wled", 171 }, 172 }; 173 174 module_platform_driver(da9052_wled_driver); 175 176 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>"); 177 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC"); 178 MODULE_LICENSE("GPL"); 179