extcon: adc_jack: adc-jack driver to support 3.5 pi or simliar devices
External connector devices that decides connection information based on ADC values may use adc-jack device driver. The user simply needs to provide a table of adc range and connection states. Then, extcon framework will automatically notify others. Changes in V1: added Lars-Peter Clausen suggested changes: Using macros to get rid of boiler plate code such as devm_kzalloc and module_platform_driver.Other changes suggested are related to coding guidelines. Changes in V2: Removed some unnecessary checks and changed the way we are un-regitering extcon and freeing the irq while removing. Changes in V3: Renamed the files to comply with extcon naming. Changes in V4: Added the cancel_work_sync during removing of driver. Changes in V5: Added the dependency of IIO in Kconfig. Changes in V6: Some nitpicks related to naming. Changes in this version: V6 patch version patch broke the build: ERROR: "extcon_cable_name" [drivers/extcon/extcon-adc-jack.ko] undefined! Fixed it in this version. Acked-by: Jonathan Cameron <jic23@kernel.org> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: anish kumar <anish.singh@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
anish kumar
Greg Kroah-Hartman
parent
c338bb0380
commit
19939860dc
4 changed files with 276 additions and 0 deletions
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@ -21,6 +21,12 @@ config EXTCON_GPIO
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Say Y here to enable GPIO based extcon support. Note that GPIO
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extcon supports single state per extcon instance.
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config EXTCON_ADC_JACK
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tristate "ADC Jack extcon support"
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depends on IIO
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help
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Say Y here to enable extcon device driver based on ADC values.
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config EXTCON_MAX77693
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tristate "MAX77693 EXTCON Support"
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depends on MFD_MAX77693
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@ -4,6 +4,7 @@
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obj-$(CONFIG_EXTCON) += extcon-class.o
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obj-$(CONFIG_EXTCON_GPIO) += extcon-gpio.o
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obj-$(CONFIG_EXTCON_ADC_JACK) += extcon-adc-jack.o
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obj-$(CONFIG_EXTCON_MAX77693) += extcon-max77693.o
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obj-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o
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obj-$(CONFIG_EXTCON_ARIZONA) += extcon-arizona.o
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198
drivers/extcon/extcon-adc-jack.c
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198
drivers/extcon/extcon-adc-jack.c
Normal file
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@ -0,0 +1,198 @@
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/*
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* drivers/extcon/extcon-adc-jack.c
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*
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* Analog Jack extcon driver with ADC-based detection capability.
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*
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* Copyright (C) 2012 Samsung Electronics
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* MyungJoo Ham <myungjoo.ham@samsung.com>
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*
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* Modified for calling to IIO to get adc by <anish.singh@samsung.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/slab.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/workqueue.h>
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#include <linux/iio/consumer.h>
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#include <linux/extcon/extcon-adc-jack.h>
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#include <linux/extcon.h>
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/**
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* struct adc_jack_data - internal data for adc_jack device driver
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* @edev - extcon device.
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* @cable_names - list of supported cables.
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* @num_cables - size of cable_names.
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* @adc_conditions - list of adc value conditions.
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* @num_conditions - size of adc_conditions.
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* @irq - irq number of attach/detach event (0 if not exist).
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* @handling_delay - interrupt handler will schedule extcon event
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* handling at handling_delay jiffies.
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* @handler - extcon event handler called by interrupt handler.
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* @chan - iio channel being queried.
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*/
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struct adc_jack_data {
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struct extcon_dev edev;
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const char **cable_names;
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int num_cables;
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struct adc_jack_cond *adc_conditions;
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int num_conditions;
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int irq;
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unsigned long handling_delay; /* in jiffies */
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struct delayed_work handler;
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struct iio_channel *chan;
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};
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static void adc_jack_handler(struct work_struct *work)
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{
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struct adc_jack_data *data = container_of(to_delayed_work(work),
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struct adc_jack_data,
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handler);
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u32 state = 0;
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int ret, adc_val;
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int i;
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ret = iio_read_channel_raw(data->chan, &adc_val);
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if (ret < 0) {
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dev_err(data->edev.dev, "read channel() error: %d\n", ret);
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return;
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}
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/* Get state from adc value with adc_conditions */
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for (i = 0; i < data->num_conditions; i++) {
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struct adc_jack_cond *def = &data->adc_conditions[i];
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if (!def->state)
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break;
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if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
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state = def->state;
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break;
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}
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}
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/* if no def has met, it means state = 0 (no cables attached) */
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extcon_set_state(&data->edev, state);
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}
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static irqreturn_t adc_jack_irq_thread(int irq, void *_data)
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{
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struct adc_jack_data *data = _data;
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schedule_delayed_work(&data->handler, data->handling_delay);
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return IRQ_HANDLED;
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}
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static int __devinit adc_jack_probe(struct platform_device *pdev)
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{
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struct adc_jack_data *data;
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struct adc_jack_pdata *pdata = pdev->dev.platform_data;
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int i, err = 0;
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data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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data->edev.name = pdata->name;
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if (!pdata->cable_names) {
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err = -EINVAL;
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dev_err(&pdev->dev, "error: cable_names not defined.\n");
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goto out;
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}
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data->edev.supported_cable = pdata->cable_names;
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/* Check the length of array and set num_cables */
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for (i = 0; data->edev.supported_cable[i]; i++)
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;
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if (i == 0 || i > SUPPORTED_CABLE_MAX) {
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err = -EINVAL;
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dev_err(&pdev->dev, "error: pdata->cable_names size = %d\n",
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i - 1);
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goto out;
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}
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data->num_cables = i;
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if (!pdata->adc_conditions ||
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!pdata->adc_conditions[0].state) {
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err = -EINVAL;
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dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
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goto out;
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}
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data->adc_conditions = pdata->adc_conditions;
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/* Check the length of array and set num_conditions */
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for (i = 0; data->adc_conditions[i].state; i++)
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;
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data->num_conditions = i;
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data->chan = iio_channel_get(dev_name(&pdev->dev),
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pdata->consumer_channel);
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if (IS_ERR(data->chan)) {
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err = PTR_ERR(data->chan);
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goto out;
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}
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data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
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INIT_DELAYED_WORK_DEFERRABLE(&data->handler, adc_jack_handler);
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platform_set_drvdata(pdev, data);
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err = extcon_dev_register(&data->edev, &pdev->dev);
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if (err)
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goto out;
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data->irq = platform_get_irq(pdev, 0);
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if (!data->irq) {
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dev_err(&pdev->dev, "platform_get_irq failed\n");
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err = -ENODEV;
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goto err_irq;
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}
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err = request_any_context_irq(data->irq, adc_jack_irq_thread,
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pdata->irq_flags, pdata->name, data);
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if (err) {
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dev_err(&pdev->dev, "error: irq %d\n", data->irq);
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err = -EINVAL;
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goto err_irq;
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}
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goto out;
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err_irq:
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extcon_dev_unregister(&data->edev);
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out:
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return err;
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}
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static int __devexit adc_jack_remove(struct platform_device *pdev)
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{
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struct adc_jack_data *data = platform_get_drvdata(pdev);
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free_irq(data->irq, data);
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cancel_work_sync(&data->handler.work);
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extcon_dev_unregister(&data->edev);
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return 0;
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}
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static struct platform_driver adc_jack_driver = {
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.probe = adc_jack_probe,
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.remove = __devexit_p(adc_jack_remove),
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.driver = {
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.name = "adc-jack",
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.owner = THIS_MODULE,
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},
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};
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module_platform_driver(adc_jack_driver);
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71
include/linux/extcon/extcon-adc-jack.h
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71
include/linux/extcon/extcon-adc-jack.h
Normal file
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@ -0,0 +1,71 @@
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/*
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* include/linux/extcon/extcon-adc-jack.h
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*
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* Analog Jack extcon driver with ADC-based detection capability.
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*
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* Copyright (C) 2012 Samsung Electronics
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* MyungJoo Ham <myungjoo.ham@samsung.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#ifndef _EXTCON_ADC_JACK_H_
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#define _EXTCON_ADC_JACK_H_ __FILE__
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#include <linux/module.h>
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#include <linux/extcon.h>
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/**
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* struct adc_jack_cond - condition to use an extcon state
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* @state - the corresponding extcon state (if 0, this struct denotes
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* the last adc_jack_cond element among the array)
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* @min_adc - min adc value for this condition
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* @max_adc - max adc value for this condition
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*
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* For example, if { .state = 0x3, .min_adc = 100, .max_adc = 200}, it means
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* that if ADC value is between (inclusive) 100 and 200, than the cable 0 and
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* 1 are attached (1<<0 | 1<<1 == 0x3)
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*
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* Note that you don't need to describe condition for "no cable attached"
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* because when no adc_jack_cond is met, state = 0 is automatically chosen.
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*/
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struct adc_jack_cond {
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u32 state; /* extcon state value. 0 if invalid */
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u32 min_adc;
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u32 max_adc;
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};
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/**
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* struct adc_jack_pdata - platform data for adc jack device.
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* @name - name of the extcon device. If null, "adc-jack" is used.
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* @consumer_channel - Unique name to identify the channel on the consumer
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* side. This typically describes the channels used within
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* the consumer. E.g. 'battery_voltage'
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* @cable_names - array of cable names ending with null.
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* @adc_contitions - array of struct adc_jack_cond conditions ending
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* with .state = 0 entry. This describes how to decode
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* adc values into extcon state.
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* @irq_flags - irq flags used for the @irq
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* @handling_delay_ms - in some devices, we need to read ADC value some
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* milli-seconds after the interrupt occurs. You may
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* describe such delays with @handling_delay_ms, which
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* is rounded-off by jiffies.
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*/
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struct adc_jack_pdata {
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const char *name;
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const char *consumer_channel;
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/*
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* The last entry should be NULL
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*/
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const char **cable_names;
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/* The last entry's state should be 0 */
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struct adc_jack_cond *adc_conditions;
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unsigned long irq_flags;
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unsigned long handling_delay_ms; /* in ms */
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};
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#endif /* _EXTCON_ADC_JACK_H */
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