Re: [PATCH] [V2]power: battery: Generic battery driver using IIO

From: anish kumar
Date: Fri Sep 21 2012 - 10:35:28 EST


On Thu, 2012-09-20 at 18:45 -0700, Anton Vorontsov wrote:
> On Tue, Sep 18, 2012 at 11:33:20PM +0530, anish kumar wrote:
> > From: anish kumar <anish198519851985@xxxxxxxxx>
> >
> > In last version:
> > Addressed concerns raised by lars:
> > a. made the adc_bat per device.
> > b. get the IIO channel using hardcoded channel names.
> > c. Minor issues related to gpio_is_valid and some code
> > refactoring.
> >
> > In V1:
> > Addressed concerns raised by Anton:
> > a. changed the struct name to gab(generic adc battery).
> > b. Added some functions to neaten the code.
> > c. Some minor coding guidelines changes.
> > d. Used the latest function introduce by lars:
> > iio_read_channel_processed to streamline the code.
> >
> > In V2:
> > Addressed concerns by lars:
> > a. No need of allocating memory for channels.Make it array.
> > b. Code restructring, coding style and following kernel guidelines changes
> > suggested by him.
> >
> > Signed-off-by: anish kumar <anish198519851985@xxxxxxxxx>
> > ---
>
> OK, the code turns into a nicely looking driver, congratulations!
>
> I noticed that patch depends on iio_read_channel_processed(), so it will
> have to go via IIO tree. But I'll happily give you my ack, once the final
> bits are fixed...
>
> The biggest issues is that the patch is missing Kconfig and Makefile
> entries. :-)
>
> And some cosmetic stuff down below...
>
> > drivers/power/generic-adc-battery.c | 429 +++++++++++++++++++++++++++++
> > include/linux/power/generic-adc-battery.h | 28 ++
> > 2 files changed, 457 insertions(+), 0 deletions(-)
> > create mode 100644 drivers/power/generic-adc-battery.c
> > create mode 100644 include/linux/power/generic-adc-battery.h
> >
> > diff --git a/drivers/power/generic-adc-battery.c b/drivers/power/generic-adc-battery.c
> > new file mode 100644
> > index 0000000..746a210
> > --- /dev/null
> > +++ b/drivers/power/generic-adc-battery.c
> > @@ -0,0 +1,429 @@
> > +/*
> > + * Generic battery driver code using IIO
> > + * Copyright (C) 2012, Anish Kumar <anish198519851985@xxxxxxxxx>
> > + * based on jz4740-battery.c
> > + * based on s3c_adc_battery.c
> > + *
> > + * This file is subject to the terms and conditions of the GNU General Public
> > + * License. See the file COPYING in the main directory of this archive for
> > + * more details.
> > + *
> > + */
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/power_supply.h>
> > +#include <linux/gpio.h>
> > +#include <linux/err.h>
> > +#include <linux/timer.h>
> > +#include <linux/jiffies.h>
> > +#include <linux/errno.h>
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/slab.h>
> > +#include <linux/iio/consumer.h>
> > +#include <linux/iio/types.h>
> > +#include <linux/power/generic-adc-battery.h>
> > +
> > +#define JITTER_DEFAULT 10 /* hope 10ms is enough */
> > +
> > +enum gab_chan_type {
> > + VOLTAGE = 0,
> > + CURRENT,
> > + POWER,
> > + MAX_CHAN_TYPE
>
> These are still in the global namespace. Please prefix them with
> GAB_.
>
> > +};
> > +
> > +/*
> > + * gab_chan_name suggests the standard channel names for commonly used
> > + * channel types.
> > + */
> > +static const char *const gab_chan_name[] = {
> > + [VOLTAGE] = "voltage",
> > + [CURRENT] = "current",
> > + [POWER] = "power",
> > +};
> > +
> > +struct gab {
> > + struct power_supply psy;
> > + struct iio_channel *channel[MAX_CHAN_TYPE];
> > + struct gab_platform_data *pdata;
> > + struct delayed_work bat_work;
> > + int level;
> > + int status;
> > + int cable_plugged:1;
>
> This gives me:
>
> CHECK drivers/power/generic-adc-battery.c
> drivers/power/generic-adc-battery.c:53:32: error: dubious one-bit signed bitfield
>
> You can just use 'bool' instead of 'int'.
>
> > +};
> > +
> > +struct gab *to_generic_bat(struct power_supply *psy)
> > +{
> > + return container_of(psy, struct gab, psy);
>
> No need for double whitespace.
>
> > +}
> > +
> > +static void gab_ext_power_changed(struct power_supply *psy)
> > +{
> > + struct gab *adc_bat;
> > + adc_bat = to_generic_bat(psy);
>
> This can be merged into one line.
>
> struct gab *adc_bat = to_generic_bat(psy);
>
> > +
> > + schedule_delayed_work(&adc_bat->bat_work,
> > + msecs_to_jiffies(0));
>
> This will fit into one line.
>
> > +}
> > +
> > +static const enum power_supply_property gab_props[] = {
> > + POWER_SUPPLY_PROP_STATUS,
> > + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
> > + POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
> > + POWER_SUPPLY_PROP_CHARGE_NOW,
> > + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> > + POWER_SUPPLY_PROP_CURRENT_NOW,
> > + POWER_SUPPLY_PROP_TECHNOLOGY,
> > + POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
> > + POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
> > + POWER_SUPPLY_PROP_MODEL_NAME,
> > +};
> > +
> > +/*
> > + * This properties are set based on the received platform data and this
> > + * should correspond one-to-one with enum chan_type.
> > + */
> > +static const enum power_supply_property gab_dyn_props[] = {
> > + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> > + POWER_SUPPLY_PROP_CURRENT_NOW,
> > + POWER_SUPPLY_PROP_POWER_NOW,
> > +};
> > +
> > +static bool gab_charge_finished(struct gab *adc_bat)
> > +{
> > + struct gab_platform_data *pdata = adc_bat->pdata;
> > + bool ret = gpio_get_value(pdata->gpio_charge_finished);
> > + bool inv = pdata->gpio_inverted;
> > +
> > + if (!gpio_is_valid(pdata->gpio_charge_finished))
> > + return false;
> > + return ret ^ inv;
> > +}
> > +
> > +static int gab_get_status(struct gab *adc_bat)
> > +{
> > + struct gab_platform_data *pdata = adc_bat->pdata;
> > + struct power_supply_info *bat_info;
> > +
> > + bat_info = &pdata->battery_info;
> > + if (adc_bat->level == bat_info->charge_full_design)
> > + return POWER_SUPPLY_STATUS_FULL;
> > + else
>
> No need for this else.
>
> > + return adc_bat->status;
> > +}
> > +
> > +enum gab_chan_type gab_prop_to_chan(enum power_supply_property psp)
> > +{
> > + switch (psp) {
> > + case POWER_SUPPLY_PROP_POWER_NOW:
> > + return POWER;
> > + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> > + return VOLTAGE;
> > + case POWER_SUPPLY_PROP_CURRENT_NOW:
> > + return CURRENT;
> > + default:
> > + WARN_ON(1);
> > + break;
> > + }
> > + return POWER;
> > +}
> > +
> > +static int read_channel(struct gab *adc_bat, enum power_supply_property psp,
> > + int *result)
> > +{
> > + int ret = 0;
>
> = 0 initializer is not needed.
>
> > + int chan_index;
> > +
> > + chan_index = gab_prop_to_chan(psp);
> > + ret = iio_read_channel_processed(adc_bat->channel[chan_index],
> > + result);
> > + if (ret < 0)
> > + pr_err("read channel error\n");
> > + return ret;
> > +}
> > +
> > +static int gab_get_property(struct power_supply *psy,
> > + enum power_supply_property psp, union power_supply_propval *val)
> > +{
> > + struct gab *adc_bat;
> > + struct gab_platform_data *pdata;
> > + struct power_supply_info *bat_info;
> > + int result = 0;
> > + int ret = 0;
> > +
> > + adc_bat = to_generic_bat(psy);
> > + if (!adc_bat) {
> > + dev_err(psy->dev, "no battery infos ?!\n");
> > + return -EINVAL;
> > + }
> > + pdata = adc_bat->pdata;
> > + bat_info = &pdata->battery_info;
> > +
> > + switch (psp) {
> > + case POWER_SUPPLY_PROP_STATUS:
> > + gab_get_status(adc_bat);
> > + break;
> > + case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
> > + val->intval = 0;
> > + break;
> > + case POWER_SUPPLY_PROP_CHARGE_NOW:
> > + val->intval = pdata->cal_charge(result);
> > + break;
> > + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> > + case POWER_SUPPLY_PROP_CURRENT_NOW:
> > + case POWER_SUPPLY_PROP_POWER_NOW:
> > + ret = read_channel(adc_bat, psp, &result);
> > + if (ret < 0)
> > + goto err;
> > + val->intval = result;
> > + break;
> > + case POWER_SUPPLY_PROP_TECHNOLOGY:
> > + val->intval = bat_info->technology;
> > + break;
> > + case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
> > + val->intval = bat_info->voltage_min_design;
> > + break;
> > + case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
> > + val->intval = bat_info->voltage_max_design;
> > + break;
> > + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> > + val->intval = bat_info->charge_full_design;
> > + break;
> > + case POWER_SUPPLY_PROP_MODEL_NAME:
> > + val->strval = bat_info->name;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > +err:
> > + return ret;
> > +}
> > +
> > +static void gab_work(struct work_struct *work)
> > +{
> > + struct gab *adc_bat;
> > + struct gab_platform_data *pdata;
> > + struct delayed_work *delayed_work;
> > + int is_plugged;
> > + int status;
> > +
> > + delayed_work = container_of(work, struct delayed_work, work);
> > + adc_bat = container_of(delayed_work, struct gab, bat_work);
> > + pdata = adc_bat->pdata;
> > + status = adc_bat->status;
>
> Since moving these into initializers would create too long lines,
> in this case it's OK to do them separately. So, these are OK.
>
> (Just trying to explain the rationale behind what should go into
> initializers and what is not necessary.)
This is the only reason for which I am submitting this patch.This
is the most important information.
I will address all your other comments and submitting the patch in
few minutes.
>
> > + is_plugged = power_supply_am_i_supplied(&adc_bat->psy);
> > + adc_bat->cable_plugged = is_plugged;
> > +
> > + if (!is_plugged)
> > + adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
> > + else if (gab_charge_finished(adc_bat))
> > + adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> > + else
> > + adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
> > +
> > + if (status != adc_bat->status)
> > + power_supply_changed(&adc_bat->psy);
> > +}
> > +
> > +static irqreturn_t gab_charged(int irq, void *dev_id)
> > +{
> > + struct gab *adc_bat = dev_id;
> > + struct gab_platform_data *pdata;
> > + int delay;
> > +
> > + pdata = adc_bat->pdata;
>
> Pdata can go into initializer. I.e.
>
> struct gab_platform_data *pdata = adc_bat->pdata;
>
> > + delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
> > +
> > + schedule_delayed_work(&adc_bat->bat_work,
> > + msecs_to_jiffies(delay));
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static int __devinit gab_probe(struct platform_device *pdev)
> > +{
> > + struct gab *adc_bat;
> > + struct power_supply *psy;
>
> No need for the tab between 'power_supply' and '*psy', a
> whitespace would work. :-)
>
> > + struct gab_platform_data *pdata = pdev->dev.platform_data;
> > + enum power_supply_property *properties;
> > + int ret = 0;
> > + int chan;
> > + int index = 0;
> > +
> > + adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
> > + if (!adc_bat) {
> > + dev_err(&pdev->dev, "failed to allocate memory\n");
> > + return -ENOMEM;
> > + }
> > +
> > + psy = &adc_bat->psy;
> > + psy->name = pdata->battery_info.name;
> > +
> > + /* bootup default values for the battery */
> > + adc_bat->cable_plugged = 0;
> > + adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
> > + psy->type = POWER_SUPPLY_TYPE_BATTERY;
> > + psy->get_property = gab_get_property;
> > + psy->external_power_changed = gab_ext_power_changed;
> > + adc_bat->pdata = pdata;
> > +
> > + /* calculate the total number of channels */
> > + chan = ARRAY_SIZE(gab_chan_name);
> > +
> > + /*
> > + * copying the static properties and allocating extra memory for holding
> > + * the extra configurable properties received from platform data.
> > + */
> > + psy->properties = kcalloc(ARRAY_SIZE(gab_props) +
> > + ARRAY_SIZE(gab_chan_name),
> > + sizeof(*psy->properties), GFP_KERNEL);
> > + if (!psy->properties) {
> > + ret = -ENOMEM;
> > + goto first_mem_fail;
> > + }
> > +
> > + memcpy(psy->properties, gab_props, sizeof(gab_props));
> > + properties = psy->properties + sizeof(gab_props);
> > +
> > + /*
> > + * getting channel from iio and copying the battery properties
> > + * based on the channel supported by consumer device.
> > + */
> > + for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
> > + adc_bat->channel[chan] = iio_channel_get(dev_name(&pdev->dev),
> > + gab_chan_name[chan]);
> > + if (IS_ERR(adc_bat->channel[chan])) {
> > + ret = PTR_ERR(adc_bat->channel[chan]);
> > + } else {
> > + /* copying properties for supported channels only */
> > + memcpy(properties + sizeof(*(psy->properties)) * index,
> > + &gab_dyn_props[chan],
> > + sizeof(gab_dyn_props[chan]));
> > + index++;
> > + }
> > + }
> > +
> > + /* none of the channels are supported so let's bail out */
> > + if (index == ARRAY_SIZE(gab_chan_name))
> > + goto second_mem_fail;
> > +
> > + /*
> > + * Total number of properties is equal to static properties
> > + * plus the dynamic properties.Some properties may not be set
> > + * as come channels may be not be supported by the device.So
> > + * we need to take care of that.
> > + */
> > + psy->num_properties = ARRAY_SIZE(gab_props) + index;
> > +
> > + ret = power_supply_register(&pdev->dev, psy);
> > + if (ret)
> > + goto err_reg_fail;
> > +
> > + INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);
> > +
> > + if (gpio_is_valid(pdata->gpio_charge_finished)) {
> > + int irq;
> > + ret = gpio_request(pdata->gpio_charge_finished, "charged");
> > + if (ret)
> > + goto gpio_req_fail;
> > +
> > + irq = gpio_to_irq(pdata->gpio_charge_finished);
> > + ret = request_any_context_irq(irq, gab_charged,
> > + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> > + "battery charged", adc_bat);
> > + if (ret)
> > + goto err_gpio;
> > + }
> > +
> > + platform_set_drvdata(pdev, adc_bat);
> > +
> > + /* Schedule timer to check current status */
> > + schedule_delayed_work(&adc_bat->bat_work,
> > + msecs_to_jiffies(0));
> > + return 0;
> > +
> > +err_gpio:
> > + gpio_free(pdata->gpio_charge_finished);
> > +gpio_req_fail:
> > + power_supply_unregister(psy);
> > +err_reg_fail:
> > + for (chan = 0; ARRAY_SIZE(gab_chan_name); chan++)
> > + iio_channel_release(adc_bat->channel[chan]);
> > +second_mem_fail:
> > + kfree(psy->properties);
> > +first_mem_fail:
> > + return ret;
> > +}
> > +
> > +static int __devexit gab_remove(struct platform_device *pdev)
> > +{
> > + int chan;
> > + struct gab_platform_data *pdata;
>
> No need for the tab before '*pdata', a whitespace is more appropriate
> here.
>
> > + struct gab *adc_bat = platform_get_drvdata(pdev);
> > +
> > + pdata = adc_bat->pdata;
>
> This can go into initializer, i.e.
>
> struct gab *adc_bat = platform_get_drvdata(pdev);
> struct gab_platform_data *pdata = adc_bat->pdata;
>
> > + power_supply_unregister(&adc_bat->psy);
> > +
> > + if (gpio_is_valid(pdata->gpio_charge_finished)) {
> > + free_irq(gpio_to_irq(pdata->gpio_charge_finished), adc_bat);
> > + gpio_free(pdata->gpio_charge_finished);
> > + }
> > +
> > + for (chan = 0; ARRAY_SIZE(gab_chan_name); chan++)
> > + iio_channel_release(adc_bat->channel[chan]);
> > +
> > + kfree(adc_bat->psy.properties);
> > + cancel_delayed_work(&adc_bat->bat_work);
> > + return 0;
> > +}
> > +
> > +#ifdef CONFIG_PM
> > +static int gab_suspend(struct device *dev)
> > +{
> > + struct gab *adc_bat = dev_get_drvdata(dev);
> > +
> > + cancel_delayed_work_sync(&adc_bat->bat_work);
> > + adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
> > + return 0;
> > +}
> > +
> > +static int gab_resume(struct device *dev)
> > +{
> > + struct gab *adc_bat = dev_get_drvdata(dev);
> > + struct gab_platform_data *pdata;
> > + int delay;
> > +
> > + pdata = adc_bat->pdata;
>
> ...into initializer.
>
> > + delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
> > +
> > + /* Schedule timer to check current status */
> > + schedule_delayed_work(&adc_bat->bat_work,
> > + msecs_to_jiffies(delay));
> > + return 0;
> > +}
> > +
> > +static const struct dev_pm_ops gab_pm_ops = {
> > + .suspend = gab_suspend,
> > + .resume = gab_resume,
> > +};
> > +
> > +#define GAB_PM_OPS (&gab_pm_ops)
> > +#else
> > +#define GAB_PM_OPS (NULL)
> > +#endif
> > +
> > +static struct platform_driver gab_driver = {
> > + .driver = {
> > + .name = "generic-adc-battery",
> > + .owner = THIS_MODULE,
> > + .pm = GAB_PM_OPS
> > + },
> > + .probe = gab_probe,
> > + .remove = __devexit_p(gab_remove),
> > +};
> > +module_platform_driver(gab_driver);
> > +
> > +MODULE_AUTHOR("anish kumar <anish198519851985@xxxxxxxxx>");
> > +MODULE_DESCRIPTION("generic battery driver using IIO");
> > +MODULE_LICENSE("GPL");
> > diff --git a/include/linux/power/generic-adc-battery.h b/include/linux/power/generic-adc-battery.h
> > new file mode 100644
> > index 0000000..aa9ea14
> > --- /dev/null
> > +++ b/include/linux/power/generic-adc-battery.h
> > @@ -0,0 +1,28 @@
> > +/*
>
> Can place your copyright here.
>
> > + * 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 GENERIC_ADC_BATTERY_H
> > +#define GENERIC_ADC_BATTERY_H
> > +
> > +/**
> > + * struct gab_platform_data - platform_data for generic adc iio battery driver.
> > + * @battery_info: recommended structure to specify static power supply
> > + * parameters
> > + * @cal_charge: calculate charge level.
> > + * @gpio_charge_finished: gpio for the charger.
> > + * @gpio_inverted: Should be 1 if the GPIO is active low otherwise 0
> > + * &jitter_delay: delay required after the interrupt to check battery
> > + * status.Default set is 10ms.
>
> "&"?
>
> > + */
> > +struct gab_platform_data {
> > + struct power_supply_info battery_info;
> > + int (*cal_charge)(long value);
> > + int gpio_charge_finished;
> > + bool gpio_inverted;
> > + int jitter_delay;
> > +};
> > +
> > +#endif /* GENERIC_ADC_BATTERY_H */
> > --
> > 1.7.1


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