linux/drivers/extcon/extcon-adc-jack.c

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/*
* drivers/extcon/extcon-adc-jack.c
*
* Analog Jack extcon driver with ADC-based detection capability.
*
* Copyright (C) 2012 Samsung Electronics
* MyungJoo Ham <myungjoo.ham@samsung.com>
*
* Modified for calling to IIO to get adc by <anish.singh@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/module.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/iio/consumer.h>
#include <linux/extcon/extcon-adc-jack.h>
#include <linux/extcon.h>
/**
* struct adc_jack_data - internal data for adc_jack device driver
* @edev - extcon device.
* @cable_names - list of supported cables.
* @num_cables - size of cable_names.
* @adc_conditions - list of adc value conditions.
* @num_conditions - size of adc_conditions.
* @irq - irq number of attach/detach event (0 if not exist).
* @handling_delay - interrupt handler will schedule extcon event
* handling at handling_delay jiffies.
* @handler - extcon event handler called by interrupt handler.
* @chan - iio channel being queried.
*/
struct adc_jack_data {
struct extcon_dev edev;
const char **cable_names;
int num_cables;
struct adc_jack_cond *adc_conditions;
int num_conditions;
int irq;
unsigned long handling_delay; /* in jiffies */
struct delayed_work handler;
struct iio_channel *chan;
};
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 state = 0;
int ret, adc_val;
int i;
ret = iio_read_channel_raw(data->chan, &adc_val);
if (ret < 0) {
dev_err(data->edev.dev, "read channel() error: %d\n", ret);
return;
}
/* Get state from adc value with adc_conditions */
for (i = 0; i < data->num_conditions; i++) {
struct adc_jack_cond *def = &data->adc_conditions[i];
if (!def->state)
break;
if (def->min_adc <= adc_val && def->max_adc >= adc_val) {
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 __devinit 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 = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->edev.name = pdata->name;
if (!pdata->cable_names) {
err = -EINVAL;
dev_err(&pdev->dev, "error: cable_names not defined.\n");
goto out;
}
data->edev.supported_cable = pdata->cable_names;
/* 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\n",
i - 1);
goto out;
}
data->num_cables = i;
if (!pdata->adc_conditions ||
!pdata->adc_conditions[0].state) {
err = -EINVAL;
dev_err(&pdev->dev, "error: adc_conditions not defined.\n");
goto out;
}
data->adc_conditions = pdata->adc_conditions;
/* Check the length of array and set num_conditions */
for (i = 0; data->adc_conditions[i].state; i++)
;
data->num_conditions = i;
data->chan = iio_channel_get(dev_name(&pdev->dev),
pdata->consumer_channel);
if (IS_ERR(data->chan)) {
err = PTR_ERR(data->chan);
goto out;
}
data->handling_delay = msecs_to_jiffies(pdata->handling_delay_ms);
Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue changes from Tejun Heo: "This is workqueue updates for v3.7-rc1. A lot of activities this round including considerable API and behavior cleanups. * delayed_work combines a timer and a work item. The handling of the timer part has always been a bit clunky leading to confusing cancelation API with weird corner-case behaviors. delayed_work is updated to use new IRQ safe timer and cancelation now works as expected. * Another deficiency of delayed_work was lack of the counterpart of mod_timer() which led to cancel+queue combinations or open-coded timer+work usages. mod_delayed_work[_on]() are added. These two delayed_work changes make delayed_work provide interface and behave like timer which is executed with process context. * A work item could be executed concurrently on multiple CPUs, which is rather unintuitive and made flush_work() behavior confusing and half-broken under certain circumstances. This problem doesn't exist for non-reentrant workqueues. While non-reentrancy check isn't free, the overhead is incurred only when a work item bounces across different CPUs and even in simulated pathological scenario the overhead isn't too high. All workqueues are made non-reentrant. This removes the distinction between flush_[delayed_]work() and flush_[delayed_]_work_sync(). The former is now as strong as the latter and the specified work item is guaranteed to have finished execution of any previous queueing on return. * In addition to the various bug fixes, Lai redid and simplified CPU hotplug handling significantly. * Joonsoo introduced system_highpri_wq and used it during CPU hotplug. There are two merge commits - one to pull in IRQ safe timer from tip/timers/core and the other to pull in CPU hotplug fixes from wq/for-3.6-fixes as Lai's hotplug restructuring depended on them." Fixed a number of trivial conflicts, but the more interesting conflicts were silent ones where the deprecated interfaces had been used by new code in the merge window, and thus didn't cause any real data conflicts. Tejun pointed out a few of them, I fixed a couple more. * 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits) workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending() workqueue: use cwq_set_max_active() helper for workqueue_set_max_active() workqueue: introduce cwq_set_max_active() helper for thaw_workqueues() workqueue: remove @delayed from cwq_dec_nr_in_flight() workqueue: fix possible stall on try_to_grab_pending() of a delayed work item workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback() workqueue: use __cpuinit instead of __devinit for cpu callbacks workqueue: rename manager_mutex to assoc_mutex workqueue: WORKER_REBIND is no longer necessary for idle rebinding workqueue: WORKER_REBIND is no longer necessary for busy rebinding workqueue: reimplement idle worker rebinding workqueue: deprecate __cancel_delayed_work() workqueue: reimplement cancel_delayed_work() using try_to_grab_pending() workqueue: use mod_delayed_work() instead of __cancel + queue workqueue: use irqsafe timer for delayed_work workqueue: clean up delayed_work initializers and add missing one workqueue: make deferrable delayed_work initializer names consistent workqueue: cosmetic whitespace updates for macro definitions workqueue: deprecate system_nrt[_freezable]_wq workqueue: deprecate flush[_delayed]_work_sync() ...
2012-10-02 16:54:49 +00:00
INIT_DEFERRABLE_WORK(&data->handler, adc_jack_handler);
platform_set_drvdata(pdev, data);
err = extcon_dev_register(&data->edev, &pdev->dev);
if (err)
goto out;
data->irq = platform_get_irq(pdev, 0);
if (!data->irq) {
dev_err(&pdev->dev, "platform_get_irq failed\n");
err = -ENODEV;
goto err_irq;
}
err = request_any_context_irq(data->irq, adc_jack_irq_thread,
pdata->irq_flags, pdata->name, data);
if (err < 0) {
dev_err(&pdev->dev, "error: irq %d\n", data->irq);
goto err_irq;
}
return 0;
err_irq:
extcon_dev_unregister(&data->edev);
out:
return err;
}
static int __devexit adc_jack_remove(struct platform_device *pdev)
{
struct adc_jack_data *data = platform_get_drvdata(pdev);
free_irq(data->irq, data);
cancel_work_sync(&data->handler.work);
extcon_dev_unregister(&data->edev);
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,
},
};
module_platform_driver(adc_jack_driver);
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("ADC Jack extcon driver");
MODULE_LICENSE("GPL v2");