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 led_classdev led_dev; 30 enum lp8788_isink_number isink_num; 31 int on; 32 }; 33 34 struct lp8788_led_config { 35 enum lp8788_isink_scale scale; 36 enum lp8788_isink_number num; 37 int iout; 38 }; 39 40 static struct lp8788_led_config default_led_config = { 41 .scale = LP8788_ISINK_SCALE_100mA, 42 .num = LP8788_ISINK_3, 43 .iout = 0, 44 }; 45 46 static int lp8788_led_init_device(struct lp8788_led *led, 47 struct lp8788_led_platform_data *pdata) 48 { 49 struct lp8788_led_config *cfg = &default_led_config; 50 u8 addr, mask, val; 51 int ret; 52 53 if (pdata) { 54 cfg->scale = pdata->scale; 55 cfg->num = pdata->num; 56 cfg->iout = pdata->iout_code; 57 } 58 59 led->isink_num = cfg->num; 60 61 /* scale configuration */ 62 addr = LP8788_ISINK_CTRL; 63 mask = 1 << (cfg->num + LP8788_ISINK_SCALE_OFFSET); 64 val = cfg->scale << (cfg->num + LP8788_ISINK_SCALE_OFFSET); 65 ret = lp8788_update_bits(led->lp, addr, mask, val); 66 if (ret) 67 return ret; 68 69 /* current configuration */ 70 addr = lp8788_iout_addr[cfg->num]; 71 mask = lp8788_iout_mask[cfg->num]; 72 val = cfg->iout; 73 74 return lp8788_update_bits(led->lp, addr, mask, val); 75 } 76 77 static int lp8788_led_enable(struct lp8788_led *led, 78 enum lp8788_isink_number num, int on) 79 { 80 int ret; 81 82 u8 mask = 1 << num; 83 u8 val = on << num; 84 85 ret = lp8788_update_bits(led->lp, LP8788_ISINK_CTRL, mask, val); 86 if (ret == 0) 87 led->on = on; 88 89 return ret; 90 } 91 92 static int lp8788_brightness_set(struct led_classdev *led_cdev, 93 enum led_brightness val) 94 { 95 struct lp8788_led *led = 96 container_of(led_cdev, struct lp8788_led, led_dev); 97 98 enum lp8788_isink_number num = led->isink_num; 99 int enable, ret; 100 101 mutex_lock(&led->lock); 102 103 switch (num) { 104 case LP8788_ISINK_1: 105 case LP8788_ISINK_2: 106 case LP8788_ISINK_3: 107 ret = lp8788_write_byte(led->lp, lp8788_pwm_addr[num], val); 108 if (ret < 0) 109 goto unlock; 110 break; 111 default: 112 mutex_unlock(&led->lock); 113 return -EINVAL; 114 } 115 116 enable = (val > 0) ? 1 : 0; 117 if (enable != led->on) 118 ret = lp8788_led_enable(led, num, enable); 119 unlock: 120 mutex_unlock(&led->lock); 121 return ret; 122 } 123 124 static int lp8788_led_probe(struct platform_device *pdev) 125 { 126 struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); 127 struct lp8788_led_platform_data *led_pdata; 128 struct lp8788_led *led; 129 struct device *dev = &pdev->dev; 130 int ret; 131 132 led = devm_kzalloc(dev, sizeof(struct lp8788_led), GFP_KERNEL); 133 if (!led) 134 return -ENOMEM; 135 136 led->lp = lp; 137 led->led_dev.max_brightness = MAX_BRIGHTNESS; 138 led->led_dev.brightness_set_blocking = lp8788_brightness_set; 139 140 led_pdata = lp->pdata ? lp->pdata->led_pdata : NULL; 141 142 if (!led_pdata || !led_pdata->name) 143 led->led_dev.name = DEFAULT_LED_NAME; 144 else 145 led->led_dev.name = led_pdata->name; 146 147 mutex_init(&led->lock); 148 149 ret = lp8788_led_init_device(led, led_pdata); 150 if (ret) { 151 dev_err(dev, "led init device err: %d\n", ret); 152 return ret; 153 } 154 155 ret = devm_led_classdev_register(dev, &led->led_dev); 156 if (ret) { 157 dev_err(dev, "led register err: %d\n", ret); 158 return ret; 159 } 160 161 return 0; 162 } 163 164 static struct platform_driver lp8788_led_driver = { 165 .probe = lp8788_led_probe, 166 .driver = { 167 .name = LP8788_DEV_KEYLED, 168 }, 169 }; 170 module_platform_driver(lp8788_led_driver); 171 172 MODULE_DESCRIPTION("Texas Instruments LP8788 Keyboard LED Driver"); 173 MODULE_AUTHOR("Milo Kim"); 174 MODULE_LICENSE("GPL"); 175 MODULE_ALIAS("platform:lp8788-keyled"); 176