lkml.org 
[lkml]   [2012]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject
Date
From: anish kumar <anish198519851985@gmail.com>

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 this version:
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.

Signed-off-by: anish kumar <anish.singh@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
---
drivers/extcon/Kconfig | 5 +
drivers/extcon/Makefile | 1 +
drivers/extcon/adc_jack.c | 193 +++++++++++++++++++++++++++++++++++++++
include/linux/extcon/adc_jack.h | 77 ++++++++++++++++
4 files changed, 276 insertions(+), 0 deletions(-)
create mode 100644 drivers/extcon/adc_jack.c
create mode 100644 include/linux/extcon/adc_jack.h
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index e175c8e..596e277 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -21,6 +21,11 @@ config EXTCON_GPIO
Say Y here to enable GPIO based extcon support. Note that GPIO
extcon supports single state per extcon instance.

+config EXTCON_ADC_JACK
+ tristate "ADC Jack extcon support"
+ help
+ Say Y here to enable extcon device driver based on ADC values.
+
config EXTCON_MAX77693
tristate "MAX77693 EXTCON Support"
depends on MFD_MAX77693
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 88961b3..d95c5ea 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -4,6 +4,7 @@

obj-$(CONFIG_EXTCON) += extcon_class.o
obj-$(CONFIG_EXTCON_GPIO) += extcon_gpio.o
+obj-$(CONFIG_EXTCON_ADC_JACK) += adc_jack.o
obj-$(CONFIG_EXTCON_MAX77693) += extcon-max77693.o
obj-$(CONFIG_EXTCON_MAX8997) += extcon-max8997.o
obj-$(CONFIG_EXTCON_ARIZONA) += extcon-arizona.o
diff --git a/drivers/extcon/adc_jack.c b/drivers/extcon/adc_jack.c
new file mode 100644
index 0000000..8b80af0
--- /dev/null
+++ b/drivers/extcon/adc_jack.c
@@ -0,0 +1,193 @@
+/*
+ * 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>
+ *
+ * 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/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/iio/consumer.h>
+#include <linux/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_condition - list of adc value conditions.
+ * @num_condition - size of adc_condition.
+ * @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.
+ * @get_adc - a callback to get ADC value to identify state.
+ */
+struct adc_jack_data {
+ struct extcon_dev edev;
+
+ const char **cable_names;
+ int num_cables;
+ struct adc_jack_cond *adc_condition;
+ 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_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_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 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)
+ 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\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;
+
+ data->chan = iio_channel_get(dev_name(&pdev->dev),
+ pdata->consumer_channel);
+ if (IS_ERR(data->chan)) {
+ err = PTR_ERR(data->chan);
+ goto err_alloc;
+ }
+
+ 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 err_initwork;
+
+ data->irq = platform_get_irq(pdev, 0);
+
+ 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);
+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);
+
+ 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);
diff --git a/include/linux/extcon/adc_jack.h b/include/linux/extcon/adc_jack.h
new file mode 100644
index 0000000..ca4d1cd
--- /dev/null
+++ b/include/linux/extcon/adc_jack.h
@@ -0,0 +1,77 @@
+/*
+ * include/linux/extcon/adc_jack.h
+ *
+ * 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.
+ *
+ */
+
+#ifndef _EXTCON_ADC_JACK_H_
+#define _EXTCON_ADC_JACK_H_ __FILE__
+
+#include <linux/module.h>
+#include <linux/extcon.h>
+
+/**
+ * struct adc_jack_cond - condition to use an extcon state
+ * @state - the corresponding extcon state (if 0, this struct denotes
+ * the last adc_jack_cond element among the array)
+ * @min_adc - min adc value for this condition
+ * @max_adc - max adc value for this condition
+ *
+ * For example, if { .state = 0x3, .min_adc = 100, .max_adc = 200}, it means
+ * that if ADC value is between (inclusive) 100 and 200, than the cable 0 and
+ * 1 are attached (1<<0 | 1<<1 == 0x3)
+ *
+ * Note that you don't need to describe condition for "no cable attached"
+ * because when no adc_jack_cond is met, state = 0 is automatically chosen.
+ */
+struct adc_jack_cond {
+ u32 state; /* extcon state value. 0 if invalid */
+ u32 min_adc;
+ u32 max_adc;
+};
+
+/**
+ * struct adc_jack_pdata - platform data for adc jack device.
+ * @name - name of the extcon device. If null, "adc-jack" is used.
+ * @cable_names - array of cable names ending with null. If the array itself
+ * if null, extcon standard cable names are chosen.
+ * @adc_contition - array of struct adc_jack_cond conditions ending
+ * with .state = 0 entry. This describes how to decode
+ * adc values into extcon state.
+ * @irq - IRQ number that is triggerred by cable attach/detach
+ * events. If irq = 0, use should manually update extcon state
+ * with extcon APIs.
+ * @irq_flags - irq flags used for the @irq
+ * @handling_delay_ms - in some devices, we need to read ADC value some
+ * milli-seconds after the interrupt occurs. You may
+ * describe such delays with @handling_delay_ms, which
+ * is rounded-off by jiffies.
+ * @get_adc - the callback to read ADC value to identify cable states.
+ */
+struct adc_jack_pdata {
+ const char *name;
+ const char *consumer_channel;
+ /*
+ * NULL if standard extcon names are used.
+ * The last entry should be NULL
+ */
+ const char **cable_names;
+ /* The last entry's state should be 0 */
+ struct adc_jack_cond *adc_condition;
+
+ unsigned long irq_flags;
+ unsigned long handling_delay_ms; /* in ms */
+
+ /* When we have ADC subsystem, this can be generalized. */
+ int (*get_adc)(u32 *value);
+};
+
+#endif /* _EXTCON_ADC_JACK_H */
--
1.7.1


\
 
 \ /
  Last update: 2012-08-06 19:42    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site