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authoranish kumar <anish198519851985@gmail.com>2012-08-17 09:57:22 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-09-05 12:20:49 -0700
commit19939860dcae5a3b2e11318eb7d65b4db2e55e2b (patch)
treef7506b914b4a2093703e5bd1fb582a3ffabc6166 /drivers/extcon/extcon-adc-jack.c
parentc338bb0380b1cd64ae566d1ea7d1bfd6c811297d (diff)
downloadlinux-19939860dcae5a3b2e11318eb7d65b4db2e55e2b.tar.bz2
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>
Diffstat (limited to 'drivers/extcon/extcon-adc-jack.c')
-rw-r--r--drivers/extcon/extcon-adc-jack.c198
1 files changed, 198 insertions, 0 deletions
diff --git a/drivers/extcon/extcon-adc-jack.c b/drivers/extcon/extcon-adc-jack.c
new file mode 100644
index 000000000000..60ac3fbb4cde
--- /dev/null
+++ b/drivers/extcon/extcon-adc-jack.c
@@ -0,0 +1,198 @@
+/*
+ * 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/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);
+
+ INIT_DELAYED_WORK_DEFERRABLE(&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) {
+ dev_err(&pdev->dev, "error: irq %d\n", data->irq);
+ err = -EINVAL;
+ goto err_irq;
+ }
+
+ goto out;
+
+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);