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Message-ID: <54B2B804.70400@kernel.org>
Date: Sun, 11 Jan 2015 17:51:00 +0000
From: Jonathan Cameron <jic23@...nel.org>
To: "Tirdea, Irina" <irina.tirdea@...el.com>,
"linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"Dogaru, Vlad" <vlad.dogaru@...el.com>,
"Baluta, Daniel" <daniel.baluta@...el.com>,
Hartmut Knaack <knaack.h@....de>,
Lars-Peter Clausen <lars@...afoo.de>,
Peter Meerwald <pmeerw@...erw.net>
Subject: Re: [PATCH 8/8] iio: add driver for Freescale MMA9553
On 11/01/15 15:10, Tirdea, Irina wrote:
>
>
>> -----Original Message-----
>> From: Jonathan Cameron [mailto:jic23@...nel.org]
>> Sent: 01 January, 2015 13:58
>> To: Tirdea, Irina; linux-iio@...r.kernel.org
>> Cc: linux-kernel@...r.kernel.org; Dogaru, Vlad; Baluta, Daniel; Hartmut Knaack; Lars-Peter Clausen; Peter Meerwald
>> Subject: Re: [PATCH 8/8] iio: add driver for Freescale MMA9553
>>
>> On 19/12/14 22:57, Irina Tirdea wrote:
>>> Add support for Freescale MMA9553L Intelligent Pedometer Platform.
>>>
>>> The following functionalities are supported:
>>> - step counter (counts the number of steps using a HW register)
>>> - step detector (generates an iio event at every step the user takes)
>>> - activity recognition (rest, walking, jogging, running)
>>> - speed
>>> - calories
>>> - distance
>>>
>>> To get accurate pedometer results, the user's height, weight and gender
>>> need to be configured.
>>>
>>> The specifications can be downloaded from:
>>> http://www.freescale.com/files/sensors/doc/ref_manual/MMA955xLSWRM.pdf
>>> http://www.freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf
>>>
>>> Signed-off-by: Irina Tirdea <irina.tirdea@...el.com>
>> A few bits an bobs beyond the interface discussions in the earlier patches
>> in the series.
>>
>> A nice looking driver on the whole, for a complex little device ;)
>
> Thanks for the detailed review, Jonathan!
>
<snip>
>>> + mutex_unlock(&data->mutex);
>>> + return ret;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> + case IIO_EV_INFO_PERIOD:
>>> + switch (chan->type) {
>>> + case IIO_STEPS:
>>> + if (val < 0 || val > 255)
>>> + return -EINVAL;
>>> + mutex_lock(&data->mutex);
>>> + ret = mma9553_set_config(data, MMA9553_CONF_SPEED_STEP,
>>> + &data->conf.speed_step, val,
>>> + MMA9553_CONF_STEPCOALESCE);
>> So this makes it fire every N steps? Kind of nice, but not quite what period
>> is usually used for. We have talked about having an absolute change
>> (rather than ROC) event type before - (requires a change of N and doesn't care
>> how long it took to happen). Perhaps that makes sense here rather than
>> an instance event and a period?
> Considering the stepcoalesce option, a change event does make more
> sense. I will add IIO_CHANGE and use it instead.
>
> Adding IIO_CHANGE event type will make IIO_INSTANCE redundant (since
> instance is change with a value of 1). I know once an interface is
> introduced it cannot be changed, but since nobody is using
> IIO_INSTANCE could we remove it?
Drop it and don't worry about. ABI changes are only a problem if anyone
notices :)
>>
>>> + mutex_unlock(&data->mutex);
>>> + return ret;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +}
>>> +
>>> +static const struct iio_event_spec mma9553_step_event = {
>>> + .type = IIO_EV_TYPE_INSTANCE,
>>> + .dir = IIO_EV_DIR_NONE,
>>> + .mask_separate = BIT(IIO_EV_INFO_ENABLE) | BIT(IIO_EV_INFO_PERIOD),
>>> +};
>>> +
>>> +static const struct iio_event_spec mma9553_activity_events[] = {
>>> + {
>>> + .type = IIO_EV_TYPE_THRESH,
>>> + .dir = IIO_EV_DIR_RISING,
>>> + .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
>>> + BIT(IIO_EV_INFO_VALUE),
>>> + },
>>> + {
>>> + .type = IIO_EV_TYPE_THRESH,
>>> + .dir = IIO_EV_DIR_FALLING,
>>> + .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
>>> + BIT(IIO_EV_INFO_VALUE),
>>> + },
>>> +};
>>> +
>>> +#define MMA9553_PEDOMETER_CHANNEL(_type, _mask) { \
>>> + .type = _type, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_ENABLE) | \
>>> + BIT(IIO_CHAN_INFO_CALIBHEIGHT) | \
>>> + BIT(IIO_CHAN_INFO_CALIBGENDER) | \
>>> + _mask, \
>>> +}
>>> +
>>> +#define MMA9553_ACTIVITY_CHANNEL(_chan2) { \
>>> + .type = IIO_ACTIVITY, \
>>> + .modified = 1, \
>>> + .channel2 = _chan2, \
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
>>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBHEIGHT) | \
>>> + BIT(IIO_CHAN_INFO_CALIBGENDER), \
>>> + .event_spec = mma9553_activity_events, \
>>> + .num_event_specs = ARRAY_SIZE(mma9553_activity_events), \
>>> +}
>>> +
>>> +static const struct iio_chan_spec mma9553_channels[] = {
>>> + MMA9551_ACCEL_CHANNEL(IIO_MOD_X),
>>> + MMA9551_ACCEL_CHANNEL(IIO_MOD_Y),
>>> + MMA9551_ACCEL_CHANNEL(IIO_MOD_Z),
>>> +
>>> + {
>>> + .type = IIO_STEPS,
>>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
>>> + BIT(IIO_CHAN_INFO_ENABLE) |
>>> + BIT(IIO_CHAN_INFO_OFFSET) |
>>> + BIT(IIO_CHAN_INFO_INT_TIME),
>>> + .event_spec = &mma9553_step_event,
>>> + .num_event_specs = 1,
>>> + },
>>> +
>>> + MMA9553_PEDOMETER_CHANNEL(IIO_DISTANCE, BIT(IIO_CHAN_INFO_PROCESSED)),
>>> + MMA9553_PEDOMETER_CHANNEL(IIO_SPEED, BIT(IIO_CHAN_INFO_RAW) |
>>> + BIT(IIO_CHAN_INFO_SCALE) |
>>> + BIT(IIO_CHAN_INFO_INT_TIME)),
>>> + MMA9553_PEDOMETER_CHANNEL(IIO_CALORIES, BIT(IIO_CHAN_INFO_RAW) |
>>> + BIT(IIO_CHAN_INFO_SCALE) |
>>> + BIT(IIO_CHAN_INFO_CALIBWEIGHT)),
>>> +
>>> + MMA9553_ACTIVITY_CHANNEL(IIO_MOD_RUNNING),
>>> + MMA9553_ACTIVITY_CHANNEL(IIO_MOD_JOGGING),
>>> + MMA9553_ACTIVITY_CHANNEL(IIO_MOD_WALKING),
>>> + MMA9553_ACTIVITY_CHANNEL(IIO_MOD_STILL),
>>> +};
>>> +
>>> +static const struct iio_info mma9553_info = {
>>> + .driver_module = THIS_MODULE,
>>> + .read_raw = mma9553_read_raw,
>>> + .write_raw = mma9553_write_raw,
>>> + .read_event_config = mma9553_read_event_config,
>>> + .write_event_config = mma9553_write_event_config,
>>> + .read_event_value = mma9553_read_event_value,
>>> + .write_event_value = mma9553_write_event_value,
>>> +};
>>> +
>> Only one copy of this? We don't want to prevent people having more
>> than one of these devices attached to a given machine.
>> Hence by all means have a default version of this but then
>> clone it into the mma9553_data structure for manipulation.
>> Or have a mached array of booleans in there (same indexes)
>> to use for the "enabled"s.
>>
> Will fix this.
>
>>> +static struct mma9553_event mma9553_events[] = {
>>> + {
>>> + .type = IIO_STEPS,
>>> + .mod = IIO_NO_MOD,
>>> + .dir = IIO_EV_DIR_NONE,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_STILL,
>>> + .dir = IIO_EV_DIR_RISING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_STILL,
>>> + .dir = IIO_EV_DIR_FALLING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_WALKING,
>>> + .dir = IIO_EV_DIR_RISING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_WALKING,
>>> + .dir = IIO_EV_DIR_FALLING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_JOGGING,
>>> + .dir = IIO_EV_DIR_RISING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_JOGGING,
>>> + .dir = IIO_EV_DIR_FALLING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_RUNNING,
>>> + .dir = IIO_EV_DIR_RISING,
>>> + .enabled = false,
>>> + },
>>> + {
>>> + .type = IIO_ACTIVITY,
>>> + .mod = IIO_MOD_RUNNING,
>>> + .dir = IIO_EV_DIR_FALLING,
>>> + .enabled = false,
>>> + },
>>> +};
>>> +
>>> +static irqreturn_t mma9553_irq_handler(int irq, void *private)
>>> +{
>>> + /*
>>> + * Since we only configure the interrupt pin when an
>>> + * event is enabled, we are sure we have at least
>>> + * one event enabled at this point.
>>> + */
>> IIRC simply not supplyling the top half handler has the same effect as
>> this (though then you don't have anywhere to put the comment!)
>> Actually - I'd be tempted to grab and stash a timestamp in here to
>> increase the precision of you step timing etc.
> Initially I used a NULL pointer instead of mma9553_irq_handler in devm_request_threaded_irq, but the registration failed with "Threaded irq requested with handler=NULL and !ONESHOT".
> However, it is better to grab the timestamp anyway so I will do that here.
>
>>> + return IRQ_WAKE_THREAD;
>>> +}
>>> +
>>> +static irqreturn_t mma9553_event_handler(int irq, void *private)
>>> +{
>>> + struct iio_dev *indio_dev = private;
>>> + struct mma9553_data *data = iio_priv(indio_dev);
>>> + u16 stepcnt;
>>> + u8 activity;
>>> + struct mma9553_event *ev_activity, *ev_prev_activity, *ev_step_detect;
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = mma9553_read_activity_stepcnt(data, &activity, &stepcnt);
>>> + if (ret < 0) {
>>> + mutex_unlock(&data->mutex);
>>> + return IRQ_HANDLED;
>>> + }
>>> +
>>> + ev_prev_activity =
>>> + mma9553_get_event(data, IIO_ACTIVITY,
>>> + mma9553_activity_to_mod(data->activity),
>>> + IIO_EV_DIR_FALLING);
>>> + ev_activity =
>>> + mma9553_get_event(data, IIO_ACTIVITY,
>>> + mma9553_activity_to_mod(activity),
>>> + IIO_EV_DIR_RISING);
>>> + ev_step_detect =
>>> + mma9553_get_event(data, IIO_STEPS, IIO_NO_MOD, IIO_EV_DIR_NONE);
>>> +
>>> + if (ev_step_detect->enabled && (stepcnt != data->stepcnt)) {
>>> + data->stepcnt = stepcnt;
>>> + iio_push_event(indio_dev,
>>> + IIO_EVENT_CODE(IIO_STEPS, 0, IIO_NO_MOD,
>>> + IIO_EV_DIR_NONE, IIO_EV_TYPE_INSTANCE, 0, 0, 0),
>>> + iio_get_time_ns());
>> Worth grabbing the timestamp earlier than this for precision reasons?
>>> + }
>>> +
>>> + if (activity != data->activity) {
>>> + data->activity = activity;
>>> + /* ev_activity can be NULL if activity == ACTIVITY_UNKNOWN */
>>> + if (ev_prev_activity && ev_prev_activity->enabled)
>>> + iio_push_event(indio_dev,
>>> + IIO_EVENT_CODE(IIO_ACTIVITY, 0,
>>> + ev_prev_activity->mod,
>>> + IIO_EV_DIR_FALLING,
>>> + IIO_EV_TYPE_THRESH, 0, 0, 0),
>>> + iio_get_time_ns());
>>> +
>>> + if (ev_activity && ev_activity->enabled)
>>> + iio_push_event(indio_dev,
>>> + IIO_EVENT_CODE(IIO_ACTIVITY, 0,
>>> + ev_activity->mod,
>>> + IIO_EV_DIR_RISING,
>>> + IIO_EV_TYPE_THRESH, 0, 0, 0),
>>> + iio_get_time_ns());
>>> + }
>>> + mutex_unlock(&data->mutex);
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int mma9553_gpio_probe(struct i2c_client *client)
>>> +{
>>> + struct device *dev;
>>> + struct gpio_desc *gpio;
>>> + int ret;
>>> +
>>> + if (!client)
>>> + return -EINVAL;
>>> +
>>> + dev = &client->dev;
>>> +
>>> + /* data ready gpio interrupt pin */
>>> + gpio = devm_gpiod_get_index(dev, MMA9553_GPIO_NAME, 0);
>>> + if (IS_ERR(gpio)) {
>>> + dev_err(dev, "acpi gpio get index failed\n");
>>> + return PTR_ERR(gpio);
>>> + }
>>> +
>>> + ret = gpiod_direction_input(gpio);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + ret = gpiod_to_irq(gpio);
>>> +
>>> + dev_dbg(dev, "gpio resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static const char *mma9553_match_acpi_device(struct device *dev)
>>> +{
>>> + const struct acpi_device_id *id;
>>> +
>>> + id = acpi_match_device(dev->driver->acpi_match_table, dev);
>>> + if (!id)
>>> + return NULL;
>>> +
>>> + return dev_name(dev);
>>> +}
>>> +
>>> +static int mma9553_probe(struct i2c_client *client,
>>> + const struct i2c_device_id *id)
>>> +{
>>> + struct mma9553_data *data;
>>> + struct iio_dev *indio_dev;
>>> + const char *name = NULL;
>>> + int ret;
>>> +
>>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>>> + if (!indio_dev)
>>> + return -ENOMEM;
>>> +
>>> + data = iio_priv(indio_dev);
>>> + i2c_set_clientdata(client, indio_dev);
>>> + data->client = client;
>>> +
>>> + if (id)
>>> + name = id->name;
>>> + else if (ACPI_HANDLE(&client->dev))
>>> + name = mma9553_match_acpi_device(&client->dev);
>>> + else
>> Interesting to note the original driver doesn't have this else. Worth
>> checking?
> There was a similar check in the initial driver (it checked for name == NULL instead) that somehow got removed in a later version.
> I could add the check in mma9551 as well, but I am not sure on what is the proper way to handle this.
> There is an ongoing discussion on this: http://www.spinics.net/lists/linux-iio/msg16231.html.
> I would rather for this to be cleared out and send a separate patch to fix both drivers if needed.
>
>>> + return -ENOSYS;
>>> +
>>> + mutex_init(&data->mutex);
>>> + data->events = mma9553_events;
>>> + data->num_events = ARRAY_SIZE(mma9553_events);
>>> +
>>> + ret = mma9553_init(data);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + indio_dev->dev.parent = &client->dev;
>>> + indio_dev->channels = mma9553_channels;
>>> + indio_dev->num_channels = ARRAY_SIZE(mma9553_channels);
>>> + indio_dev->name = name;
>>> + indio_dev->modes = INDIO_DIRECT_MODE;
>>> + indio_dev->info = &mma9553_info;
>>> +
>>> + if (client->irq < 0)
>>> + client->irq = mma9553_gpio_probe(client);
>>> +
>> So this time we just have a single irq. That makes life simpler!
> Yes, mma9553 provides the option to combine all its interrupts in one status bit (while mma9551 does not).
>
>>> + if (client->irq >= 0) {
>>> + ret = devm_request_threaded_irq(&client->dev, client->irq,
>>> + mma9553_irq_handler,
>>> + mma9553_event_handler,
>>> + IRQF_TRIGGER_RISING,
>>> + MMA9553_IRQ_NAME, indio_dev);
>>> + if (ret < 0) {
>>> + dev_err(&client->dev, "request irq %d failed\n",
>>> + client->irq);
>>> + goto out_poweroff;
>>> + }
>>> +
>>> + }
>>> +
>>> + ret = iio_device_register(indio_dev);
>>> + if (ret < 0) {
>>> + dev_err(&client->dev, "unable to register iio device\n");
>>> + goto out_poweroff;
>>> + }
>>> +
>>> + ret = pm_runtime_set_active(&client->dev);
>>> + if (ret < 0)
>>> + goto out_iio_unregister;
>>> +
>>> + pm_runtime_enable(&client->dev);
>>> + pm_runtime_set_autosuspend_delay(&client->dev,
>>> + MMA9551_AUTO_SUSPEND_DELAY_MS);
>>> + pm_runtime_use_autosuspend(&client->dev);
>>> +
>>> + dev_dbg(&indio_dev->dev, "Registered device %s\n", name);
>>> + return 0;
>>> +
>>> +out_iio_unregister:
>>> + iio_device_unregister(indio_dev);
>>> +out_poweroff:
>>> + mma9551_set_device_state(client, false);
>>> + return ret;
>>> +}
>>> +
>>> +static int mma9553_remove(struct i2c_client *client)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>> + struct mma9553_data *data = iio_priv(indio_dev);
>>> +
>>> + pm_runtime_disable(&client->dev);
>>> + pm_runtime_set_suspended(&client->dev);
>>> + pm_runtime_put_noidle(&client->dev);
>>> +
>>> + iio_device_unregister(indio_dev);
>>> + mutex_lock(&data->mutex);
>>> + mma9551_set_device_state(data->client, false);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +#ifdef CONFIG_PM
>>> +static int mma9553_runtime_suspend(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct mma9553_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = mma9551_set_device_state(data->client, false);
>>> + mutex_unlock(&data->mutex);
>>> + if (ret < 0) {
>>> + dev_err(&data->client->dev, "powering off device failed\n");
>>> + return -EAGAIN;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int mma9553_runtime_resume(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct mma9553_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + ret = mma9551_set_device_state(data->client, true);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + mma9551_sleep(MMA9553_DEFAULT_SAMPLE_RATE);
>>> + return 0;
>>> +}
>>> +#endif
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int mma9553_suspend(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct mma9553_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = mma9551_set_device_state(data->client, false);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int mma9553_resume(struct device *dev)
>>> +{
>>> + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
>>> + struct mma9553_data *data = iio_priv(indio_dev);
>>> + int ret;
>>> +
>>> + mutex_lock(&data->mutex);
>>> + ret = mma9551_set_device_state(data->client, true);
>>> + mutex_unlock(&data->mutex);
>>> +
>>> + return ret;
>>> +}
>>> +#endif
>>> +
>>> +static const struct dev_pm_ops mma9553_pm_ops = {
>>> + SET_SYSTEM_SLEEP_PM_OPS(mma9553_suspend, mma9553_resume)
>>> + SET_RUNTIME_PM_OPS(mma9553_runtime_suspend,
>>> + mma9553_runtime_resume, NULL)
>>> +};
>>> +
>>> +static const struct acpi_device_id mma9553_acpi_match[] = {
>>> + {"MMA9553", 0},
>>> + {},
>>> +};
>>> +
>>> +MODULE_DEVICE_TABLE(acpi, mma9553_acpi_match);
>>> +
>>> +static const struct i2c_device_id mma9553_id[] = {
>>> + {"mma9553", 0},
>>> + {},
>>> +};
>>> +
>>> +MODULE_DEVICE_TABLE(i2c, mma9553_id);
>>> +
>>> +static struct i2c_driver mma9553_driver = {
>>> + .driver = {
>>> + .name = MMA9553_DRV_NAME,
>>> + .acpi_match_table = ACPI_PTR(mma9553_acpi_match),
>>> + .pm = &mma9553_pm_ops,
>>> + },
>>> + .probe = mma9553_probe,
>>> + .remove = mma9553_remove,
>>> + .id_table = mma9553_id,
>>> +};
>>> +
>>> +module_i2c_driver(mma9553_driver);
>>> +
>>> +MODULE_AUTHOR("Irina Tirdea <irina.tirdea@...el.com>");
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_DESCRIPTION("MMA9553L pedometer platform driver");
>>>
>
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