1 /* 2 * TI LP8788 MFD - keyled driver 3 * 4 * Copyright 2012 Texas Instruments 5 * 6 * Author: Milo(Woogyom) Kim <milo.kim@ti.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 version 2 as 10 * published by the Free Software Foundation. 11 * 12 */ 13 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 #include <linux/err.h> 17 #include <linux/platform_device.h> 18 #include <linux/leds.h> 19 #include <linux/mutex.h> 20 #include <linux/mfd/lp8788.h> 21 #include <linux/mfd/lp8788-isink.h> 22 23 #define MAX_BRIGHTNESS LP8788_ISINK_MAX_PWM 24 #define DEFAULT_LED_NAME "keyboard-backlight" 25 26 struct lp8788_led { 27 struct lp8788 *lp; 28 struct mutex lock; 29 struct work_struct work; 30 struct led_classdev led_dev; 31 enum lp8788_isink_number isink_num; 32 enum led_brightness brightness; 33 int on; 34 }; 35 36 struct lp8788_led_config { 37 enum lp8788_isink_scale scale; 38 enum lp8788_isink_number num; 39 int iout; 40 }; 41 42 static struct lp8788_led_config default_led_config = { 43 .scale = LP8788_ISINK_SCALE_100mA, 44 .num = LP8788_ISINK_3, 45 .iout = 0, 46 }; 47 48 static int lp8788_led_init_device(struct lp8788_led *led, 49 struct lp8788_led_platform_data *pdata) 50 { 51 struct lp8788_led_config *cfg = &default_led_config; 52 u8 addr, mask, val; 53 int ret; 54 55 if (pdata) { 56 cfg->scale = pdata->scale; 57 cfg->num = pdata->num; 58 cfg->iout = pdata->iout_code; 59 } 60 61 led->isink_num = cfg->num; 62 63 /* scale configuration */ 64 addr = LP8788_ISINK_CTRL; 65 mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET); 66 val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET); 67 ret = lp8788_update_bits(led->lp, addr, mask, val); 68 if (ret) 69 return ret; 70 71 /* current configuration */ 72 addr = lp8788_iout_addr[cfg->num]; 73 mask = lp8788_iout_mask[cfg->num]; 74 val = cfg->iout; 75 76 return lp8788_update_bits(led->lp, addr, mask, val); 77 } 78 79 static void lp8788_led_enable(struct lp8788_led *led, 80 enum lp8788_isink_number num, int on) 81 { 82 u8 mask = 1 << num; 83 u8 val = on << num; 84 85 if (lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val)) 86 return; 87 88 led->on = on; 89 } 90 91 static void lp8788_led_work(struct work_struct *work) 92 { 93 struct lp8788_led *led = container_of(work, struct lp8788_led, work); 94 enum lp8788_isink_number num = led->isink_num; 95 int enable; 96 u8 val = led->brightness; 97 98 mutex_lock(&led->lock); 99 100 switch (num) { 101 case LP8788_ISINK_1: 102 case LP8788_ISINK_2: 103 case LP8788_ISINK_3: 104 lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val); 105 break; 106 default: 107 mutex_unlock(&led->lock); 108 return; 109 } 110 111 enable = (val > 0) ? 1 : 0; 112 if (enable != led->on) 113 lp8788_led_enable(led, num, enable); 114 115 mutex_unlock(&led->lock); 116 } 117 118 static void lp8788_brightness_set(struct led_classdev *led_cdev, 119 enum led_brightness brt_val) 120 { 121 struct lp8788_led *led = 122 container_of(led_cdev, struct lp8788_led, led_dev); 123 124 led->brightness = brt_val; 125 schedule_work(&led->work); 126 } 127 128 static __devinit int lp8788_led_probe(struct platform_device *pdev) 129 { 130 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); 131 struct lp8788_led_platform_data *led_pdata; 132 struct lp8788_led *led; 133 int ret; 134 135 led = devm_kzalloc(lp->dev, sizeof(struct lp8788_led), GFP_KERNEL); 136 if (!led) 137 return -ENOMEM; 138 139 led->lp = lp; 140 led->led_dev.max_brightness = MAX_BRIGHTNESS; 141 led->led_dev.brightness_set = lp8788_brightness_set; 142 143 led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL; 144 145 if (!led_pdata || !led_pdata->name) 146 led->led_dev.name = DEFAULT_LED_NAME; 147 else 148 led->led_dev.name = led_pdata->name; 149 150 mutex_init(&led->lock); 151 INIT_WORK(&led->work, lp8788_led_work); 152 153 platform_set_drvdata(pdev, led); 154 155 ret = lp8788_led_init_device(led, led_pdata); 156 if (ret) { 157 dev_err(lp->dev, "led init device err: %d\n", ret); 158 return ret; 159 } 160 161 ret = led_classdev_register(lp->dev, &led->led_dev); 162 if (ret) { 163 dev_err(lp->dev, "led register err: %d\n", ret); 164 return ret; 165 } 166 167 return 0; 168 } 169 170 static int __devexit lp8788_led_remove(struct platform_device *pdev) 171 { 172 struct lp8788_led *led = platform_get_drvdata(pdev); 173 174 led_classdev_unregister(&led->led_dev); 175 flush_work_sync(&led->work); 176 177 return 0; 178 } 179 180 static struct platform_driver lp8788_led_driver = { 181 .probe = lp8788_led_probe, 182 .remove = __devexit_p(lp8788_led_remove), 183 .driver = { 184 .name = LP8788_DEV_KEYLED, 185 .owner = THIS_MODULE, 186 }, 187 }; 188 module_platform_driver(lp8788_led_driver); 189 190 MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver"); 191 MODULE_AUTHOR("Milo Kim"); 192 MODULE_LICENSE("GPL"); 193 MODULE_ALIAS("platform:lp8788-keyled"); 194