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 * @num_cables - size of cable_names. 33 * @adc_conditions - list of adc value conditions. 34 * @num_conditions - size of adc_conditions. 35 * @irq - irq number of attach/detach event (0 if not exist). 36 * @handling_delay - interrupt handler will schedule extcon event 37 * handling at handling_delay jiffies. 38 * @handler - extcon event handler called by interrupt handler. 39 * @chan - iio channel being queried. 40 */ 41 struct adc_jack_data { 42 struct extcon_dev edev; 43 44 const char **cable_names; 45 int num_cables; 46 struct adc_jack_cond *adc_conditions; 47 int num_conditions; 48 49 int irq; 50 unsigned long handling_delay; /* in jiffies */ 51 struct delayed_work handler; 52 53 struct iio_channel *chan; 54 }; 55 56 static void adc_jack_handler(struct work_struct *work) 57 { 58 struct adc_jack_data *data = container_of(to_delayed_work(work), 59 struct adc_jack_data, 60 handler); 61 u32 state = 0; 62 int ret, adc_val; 63 int i; 64 65 ret = iio_read_channel_raw(data->chan, &adc_val); 66 if (ret < 0) { 67 dev_err(data->edev.dev, "read channel() error: %d\n", ret); 68 return; 69 } 70 71 /* Get state from adc value with adc_conditions */ 72 for (i = 0; i < data->num_conditions; i++) { 73 struct adc_jack_cond *def = &data->adc_conditions[i]; 74 if (!def->state) 75 break; 76 if (def->min_adc <= adc_val && def->max_adc >= adc_val) { 77 state = def->state; 78 break; 79 } 80 } 81 /* if no def has met, it means state = 0 (no cables attached) */ 82 83 extcon_set_state(&data->edev, state); 84 } 85 86 static irqreturn_t adc_jack_irq_thread(int irq, void *_data) 87 { 88 struct adc_jack_data *data = _data; 89 90 schedule_delayed_work(&data->handler, data->handling_delay); 91 return IRQ_HANDLED; 92 } 93 94 static int adc_jack_probe(struct platform_device *pdev) 95 { 96 struct adc_jack_data *data; 97 struct adc_jack_pdata *pdata = pdev->dev.platform_data; 98 int i, err = 0; 99 100 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); 101 if (!data) 102 return -ENOMEM; 103 104 data->edev.name = pdata->name; 105 106 if (!pdata->cable_names) { 107 err = -EINVAL; 108 dev_err(&pdev->dev, "error: cable_names not defined.\n"); 109 goto out; 110 } 111 112 data->edev.supported_cable = pdata->cable_names; 113 114 /* Check the length of array and set num_cables */ 115 for (i = 0; data->edev.supported_cable[i]; i++) 116 ; 117 if (i == 0 || i > SUPPORTED_CABLE_MAX) { 118 err = -EINVAL; 119 dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n", 120 i - 1); 121 goto out; 122 } 123 data->num_cables = i; 124 125 if (!pdata->adc_conditions || 126 !pdata->adc_conditions[0].state) { 127 err = -EINVAL; 128 dev_err(&pdev->dev, "error: adc_conditions not defined.\n"); 129 goto out; 130 } 131 data->adc_conditions = pdata->adc_conditions; 132 133 /* Check the length of array and set num_conditions */ 134 for (i = 0; data->adc_conditions[i].state; i++) 135 ; 136 data->num_conditions = i; 137 138 data->chan = iio_channel_get(dev_name(&pdev->dev), 139 pdata->consumer_channel); 140 if (IS_ERR(data->chan)) { 141 err = PTR_ERR(data->chan); 142 goto out; 143 } 144 145 data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms); 146 147 INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler); 148 149 platform_set_drvdata(pdev, data); 150 151 err = extcon_dev_register(&data->edev, &pdev->dev); 152 if (err) 153 goto out; 154 155 data->irq = platform_get_irq(pdev, 0); 156 if (!data->irq) { 157 dev_err(&pdev->dev, "platform_get_irq failed\n"); 158 err = -ENODEV; 159 goto err_irq; 160 } 161 162 err = request_any_context_irq(data->irq, adc_jack_irq_thread, 163 pdata->irq_flags, pdata->name, data); 164 165 if (err < 0) { 166 dev_err(&pdev->dev, "error: irq %d\n", data->irq); 167 goto err_irq; 168 } 169 170 return 0; 171 172 err_irq: 173 extcon_dev_unregister(&data->edev); 174 out: 175 return err; 176 } 177 178 static int adc_jack_remove(struct platform_device *pdev) 179 { 180 struct adc_jack_data *data = platform_get_drvdata(pdev); 181 182 free_irq(data->irq, data); 183 cancel_work_sync(&data->handler.work); 184 extcon_dev_unregister(&data->edev); 185 186 return 0; 187 } 188 189 static struct platform_driver adc_jack_driver = { 190 .probe = adc_jack_probe, 191 .remove = adc_jack_remove, 192 .driver = { 193 .name = "adc-jack", 194 .owner = THIS_MODULE, 195 }, 196 }; 197 198 module_platform_driver(adc_jack_driver); 199 200 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); 201 MODULE_DESCRIPTION("ADC Jack extcon driver"); 202 MODULE_LICENSE("GPL v2"); 203