diff options
Diffstat (limited to 'drivers/extcon/adc_jack.c')
| -rw-r--r-- | drivers/extcon/adc_jack.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/extcon/adc_jack.c b/drivers/extcon/adc_jack.c new file mode 100644 index 0000000..8cd29b9 --- /dev/null +++ b/drivers/extcon/adc_jack.c @@ -0,0 +1,192 @@ +/* + * drivers/extcon/adc_jack.c + * + * Analog Jack extcon driver with ADC-based detection capability. + * + * Copyright (C) 2012 Samsung Electronics + * MyungJoo Ham <myungjoo.ham@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/slab.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/workqueue.h> +#include <linux/extcon.h> +#include <linux/extcon/adc_jack.h> + +static void adc_jack_handler(struct work_struct *work) +{ + struct adc_jack_data *data = container_of(to_delayed_work(work), + struct adc_jack_data, + handler); + u32 adc, state = 0; + int ret; + int i; + + if (!data->ready) + return; + + ret = data->get_adc(&adc); + if (ret) { + dev_err(data->edev.dev, "get_adc() error: %d\n", ret); + return; + } + + /* Get state from adc value with adc_condition */ + for (i = 0; i < data->num_conditions; i++) { + struct adc_jack_cond *def = &data->adc_condition[i]; + if (!def->state) + break; + if (def->min_adc <= adc && def->max_adc >= adc) { + state = def->state; + break; + } + } + /* if no def has met, it means state = 0 (no cables attached) */ + + extcon_set_state(&data->edev, state); +} + +static irqreturn_t adc_jack_irq_thread(int irq, void *_data) +{ + struct adc_jack_data *data = _data; + + schedule_delayed_work(&data->handler, data->handling_delay); + + return IRQ_HANDLED; +} + +static int adc_jack_probe(struct platform_device *pdev) +{ + struct adc_jack_data *data; + struct adc_jack_pdata *pdata = pdev->dev.platform_data; + int i, err = 0; + + data = kzalloc(sizeof(struct adc_jack_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->edev.name = pdata->name; + + if (pdata->cable_names) + data->edev.supported_cable = pdata->cable_names; + else + data->edev.supported_cable = extcon_cable_name; + + /* Check the length of array and set num_cables */ + for (i = 0; data->edev.supported_cable[i]; i++) + ; + if (i == 0 || i > SUPPORTED_CABLE_MAX) { + err = -EINVAL; + dev_err(&pdev->dev, "error: pdata->cable_names size = %d, which uses u32 bitmask and cannot exceed 32.\n", + i - 1); + goto err_alloc; + } + data->num_cables = i; + + if (!pdata->adc_condition || + !pdata->adc_condition[0].state) { + err = -EINVAL; + dev_err(&pdev->dev, "error: adc_condition not defined.\n"); + goto err_alloc; + } + data->adc_condition = pdata->adc_condition; + + /* Check the length of array and set num_conditions */ + for (i = 0; data->adc_condition[i].state; i++) + ; + data->num_conditions = i; + + if (!pdata->get_adc) { + dev_err(&pdev->dev, "error: get_adc() is mandatory.\n"); + err = -EINVAL; + goto err_alloc; + } + data->get_adc = pdata->get_adc; + data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms); + + INIT_DELAYED_WORK_DEFERRABLE(&data->handler, adc_jack_handler); + + platform_set_drvdata(pdev, data); + + if (pdata->irq) { + data->irq = pdata->irq; + + err = request_threaded_irq(data->irq, NULL, + adc_jack_irq_thread, + pdata->irq_flags, pdata->name, + data); + + if (err) { + dev_err(&pdev->dev, "error: irq %d\n", data->irq); + err = -EINVAL; + goto err_initwork; + } + } + err = extcon_dev_register(&data->edev, &pdev->dev); + if (err) + goto err_irq; + + data->ready = true; + + goto out; + +err_irq: + if (data->irq) + free_irq(data->irq, data); +err_initwork: + cancel_delayed_work_sync(&data->handler); +err_alloc: + kfree(data); +out: + return err; +} + +static int __devexit adc_jack_remove(struct platform_device *pdev) +{ + struct adc_jack_data *data = platform_get_drvdata(pdev); + + extcon_dev_unregister(&data->edev); + if (data->irq) + free_irq(data->irq, data); + platform_set_drvdata(pdev, NULL); + kfree(data); + + return 0; +} + +static struct platform_driver adc_jack_driver = { + .probe = adc_jack_probe, + .remove = __devexit_p(adc_jack_remove), + .driver = { + .name = "adc-jack", + .owner = THIS_MODULE, + }, +}; + +#define module_platform_driver(__platform_driver) \ + module_driver(__platform_driver, platform_driver_register, \ + platform_driver_unregister) +#define module_driver(__driver, __register, __unregister) \ +static int __init __driver##_init(void) \ +{ \ + return __register(&(__driver)); \ +} \ +module_init(__driver##_init); \ +static void __exit __driver##_exit(void) \ +{ \ + __unregister(&(__driver)); \ +} \ +module_exit(__driver##_exit); +module_platform_driver(adc_jack_driver); + +MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); +MODULE_DESCRIPTION("ADC jack extcon driver"); +MODULE_LICENSE("GPL"); |