1 /* 2 * drivers/extcon/extcon-adc-jack.c 3 * 4 * Analog Jack extcon driver with ADC-based detection capability. 5 * 6 * Copyright (C) 2012 Samsung Electronics 7 * MyungJoo Ham <myungjoo.ham@samsung.com> 8 * 9 * Modified for calling to IIO to get adc by <anish.singh@samsung.com> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 * 15 */ 16 17 #include <linux/module.h> 18 #include <linux/slab.h> 19 #include <linux/device.h> 20 #include <linux/platform_device.h> 21 #include <linux/err.h> 22 #include <linux/interrupt.h> 23 #include <linux/workqueue.h> 24 #include <linux/iio/consumer.h> 25 #include <linux/extcon/extcon-adc-jack.h> 26 #include <linux/extcon.h> 27 28 /** 29 * struct adc_jack_data - internal data for adc_jack device driver 30 * @edev: extcon device. 31 * @cable_names: list of supported cables. 32 * @adc_conditions: list of adc value conditions. 33 * @num_conditions: size of adc_conditions. 34 * @irq: irq number of attach/detach event (0 if not exist). 35 * @handling_delay: interrupt handler will schedule extcon event 36 * handling at handling_delay jiffies. 37 * @handler: extcon event handler called by interrupt handler. 38 * @chan: iio channel being queried. 39 */ 40 struct adc_jack_data { 41 struct extcon_dev *edev; 42 43 const unsigned int **cable_names; 44 struct adc_jack_cond *adc_conditions; 45 int num_conditions; 46 47 int irq; 48 unsigned long handling_delay; /* in jiffies */ 49 struct delayed_work handler; 50 51 struct iio_channel *chan; 52 }; 53 54 static void adc_jack_handler(struct work_struct *work) 55 { 56 struct adc_jack_data *data = container_of(to_delayed_work(work), 57 struct adc_jack_data, 58 handler); 59 u32 state = 0; 60 int ret, adc_val; 61 int i; 62 63 ret = iio_read_channel_raw(data->chan, &adc_val); 64 if (ret < 0) { 65 dev_err(&data->edev->dev, "read channel() error: %d\n", ret); 66 return; 67 } 68 69 /* Get state from adc value with adc_conditions */ 70 for (i = 0; i < data->num_conditions; i++) { 71 struct adc_jack_cond *def = &data->adc_conditions[i]; 72 if (!def->state) 73 break; 74 if (def->min_adc <= adc_val && def->max_adc >= adc_val) { 75 state = def->state; 76 break; 77 } 78 } 79 /* if no def has met, it means state = 0 (no cables attached) */ 80 81 extcon_set_state(data->edev, state); 82 } 83 84 static irqreturn_t adc_jack_irq_thread(int irq, void *_data) 85 { 86 struct adc_jack_data *data = _data; 87 88 queue_delayed_work(system_power_efficient_wq, 89 &data->handler, data->handling_delay); 90 return IRQ_HANDLED; 91 } 92 93 static int adc_jack_probe(struct platform_device *pdev) 94 { 95 struct adc_jack_data *data; 96 struct adc_jack_pdata *pdata = dev_get_platdata(&pdev->dev); 97 int i, err = 0; 98 99 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 100 if (!data) 101 return -ENOMEM; 102 103 if (!pdata->cable_names) { 104 dev_err(&pdev->dev, "error: cable_names not defined.\n"); 105 return -EINVAL; 106 } 107 108 data->edev = devm_extcon_dev_allocate(&pdev->dev, pdata->cable_names); 109 if (IS_ERR(data->edev)) { 110 dev_err(&pdev->dev, "failed to allocate extcon device\n"); 111 return -ENOMEM; 112 } 113 114 if (!pdata->adc_conditions || 115 !pdata->adc_conditions[0].state) { 116 dev_err(&pdev->dev, "error: adc_conditions not defined.\n"); 117 return -EINVAL; 118 } 119 data->adc_conditions = pdata->adc_conditions; 120 121 /* Check the length of array and set num_conditions */ 122 for (i = 0; data->adc_conditions[i].state; i++) 123 ; 124 data->num_conditions = i; 125 126 data->chan = iio_channel_get(&pdev->dev, pdata->consumer_channel); 127 if (IS_ERR(data->chan)) 128 return PTR_ERR(data->chan); 129 130 data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms); 131 132 INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler); 133 134 platform_set_drvdata(pdev, data); 135 136 err = devm_extcon_dev_register(&pdev->dev, data->edev); 137 if (err) 138 return err; 139 140 data->irq = platform_get_irq(pdev, 0); 141 if (!data->irq) { 142 dev_err(&pdev->dev, "platform_get_irq failed\n"); 143 return -ENODEV; 144 } 145 146 err = request_any_context_irq(data->irq, adc_jack_irq_thread, 147 pdata->irq_flags, pdata->name, data); 148 149 if (err < 0) { 150 dev_err(&pdev->dev, "error: irq %d\n", data->irq); 151 return err; 152 } 153 154 return 0; 155 } 156 157 static int adc_jack_remove(struct platform_device *pdev) 158 { 159 struct adc_jack_data *data = platform_get_drvdata(pdev); 160 161 free_irq(data->irq, data); 162 cancel_work_sync(&data->handler.work); 163 iio_channel_release(data->chan); 164 165 return 0; 166 } 167 168 static struct platform_driver adc_jack_driver = { 169 .probe = adc_jack_probe, 170 .remove = adc_jack_remove, 171 .driver = { 172 .name = "adc-jack", 173 }, 174 }; 175 176 module_platform_driver(adc_jack_driver); 177 178 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); 179 MODULE_DESCRIPTION("ADC Jack extcon driver"); 180 MODULE_LICENSE("GPL v2"); 181