On 22/10/16 21:46, H. Nikolaus Schaller wrote:
> Hi Jonathan,
>
>> Am 22.10.2016 um 20:33 schrieb Jonathan Cameron <jic23@xxxxxxxxxx>:
>>
>> On 17/10/16 14:57, H. Nikolaus Schaller wrote:
>>> The tsc2007 chip not only has a resistive touch screen controller but
>>> also an external AUX adc imput which can be used for an ambient
>>> light sensor, battery voltage monitoring or any general purpose.
>>>
>>> Additionally it can measure the chip temperature.
>>>
>>> This extension provides an iio interface for these adc channels.
>>>
>>> Since it is not wasting much resources and is very straightforward,
>>> we simply provide all other adc channels as optional iio interfaces
>>> as weel. This can be used for debugging or special applications.
>> well
>>>
>>> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
>> This could be cleaner done perhaps by factoring out the IIO stuff into a separate
>> file and using a header with stubs to deal with the no available case.
>>
>> There will only be a handful of stubs and it'll give you a lot cleaner code
>> in here.
>>
>> If def fun in .c files is always harder to deal with than in a header
>> where stubs are really obvious.
>
> Yes, it became a lot of #ifdefs spread over the source file.
>
> The easiest thing would be to require IIO to be enabled :)
>
> With your proposal to consider refactoring, I think the crucial part
> is the conditional allocation either through devm_iio_device_alloc()
> or devm_kzalloc(). This can be refactored into some conditional
> tsc2007_alloc().
>
> I have tried some draft (not tested and not tidied up) to check if the
> direction is good.
>
> This reduces the number of #ifdef CONFIG_IIO from 7 to 2 without introducing
> new files or includes. There are also 2 other #ifdef CONFIG_OF so it doesn't
> seem to be very complex now in comparison. And the patch itself has only a
> handful of hunks (8).
>
> Moving tsc2007_alloc into a separate file tsc2007_iio.c would only move around
> one #ifdef CONFIG_OF from tsc2007.c but IMHO makes it more difficult to understand
> because it is not really iio specific and one has to switch between two source
> files. And I would have to touch the Makefile as well.
>
> What do you think?
I'd still split it. The only bit of the IIO block that isn't specific is
a tiny chunk of the allocation code (as you've highlighted).
Even that can be avoided by adding a tiny bit more indirection than would
otherwise be needed (it's not pretty but it would give a clean separation).
It's pretty much the way this sort of optional functionality should always
be done - means that if you don't care (i.e. it's not enabled) you don't
even have to see the code.
Jonathan
>
> If generally ok, I can include that in [PATCH v5].
>
> BR and thanks,
> Nikolaus
>
>
> diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
> index 5e3c4bf..691e79f 100644
> --- a/drivers/input/touchscreen/tsc2007.c
> +++ b/drivers/input/touchscreen/tsc2007.c
> @@ -30,6 +30,7 @@
> #include <linux/of.h>
> #include <linux/of_gpio.h>
> #include <linux/input/touchscreen.h>
> +#include <linux/iio/iio.h>
>
> #define TSC2007_MEASURE_TEMP0 (0x0 << 4)
> #define TSC2007_MEASURE_AUX (0x2 << 4)
> @@ -69,9 +70,13 @@ struct ts_event {
>
> struct tsc2007 {
> struct input_dev *input;
> +#ifdef CONFIG_IIO
> + struct iio_dev *indio;
> +#endif
I wouldn't bother with this one. Just have
struct iio_dev; before this and it'll waste a whole
one pointer (+ you shouldn't need to have iio.h included
in here once you have spit the files).
> char phys[32];
>
> struct i2c_client *client;
> + struct mutex mlock;
>
> u16 model;
> u16 x_plate_ohms;
> @@ -192,7 +197,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
> while (!ts->stopped && tsc2007_is_pen_down(ts)) {
>
> /* pen is down, continue with the measurement */
> +
> + mutex_lock(&ts->mlock);
> tsc2007_read_values(ts, &tc);
> + mutex_unlock(&ts->mlock);
>
> rt = tsc2007_calculate_resistance(ts, &tc);
>
> @@ -319,6 +327,162 @@ static void tsc2007_close(struct input_dev *input_dev)
> tsc2007_stop(ts);
> }
>
> +#ifdef CONFIG_IIO
> +
> +#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
> +{ \
> + .datasheet_name = _name, \
> + .type = _type, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(_chan_info), \
> + .indexed = 1, \
> + .channel = _chan, \
> +}
> +
> +static const struct iio_chan_spec tsc2007_iio_channel[] = {
> + TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms? */
> + TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
> + TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
> +};
> +
> +static int tsc2007_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val, int *val2, long mask)
> +{
> + struct tsc2007 *tsc = iio_priv(indio_dev);
> + int adc_chan = chan->channel;
> + int ret = 0;
> +
> + if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
> + return -EINVAL;
> +
> + if (mask != IIO_CHAN_INFO_RAW)
> + return -EINVAL;
> +
> + mutex_lock(&tsc->mlock);
> +
> + switch (chan->channel) {
> + case 0:
> + *val = tsc2007_xfer(tsc, READ_X);
> + break;
> + case 1:
> + *val = tsc2007_xfer(tsc, READ_Y);
> + break;
> + case 2:
> + *val = tsc2007_xfer(tsc, READ_Z1);
> + break;
> + case 3:
> + *val = tsc2007_xfer(tsc, READ_Z2);
> + break;
> + case 4:
> + *val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
> + break;
> + case 5: {
> + struct ts_event tc;
> +
> + tc.x = tsc2007_xfer(tsc, READ_X);
> + tc.z1 = tsc2007_xfer(tsc, READ_Z1);
> + tc.z2 = tsc2007_xfer(tsc, READ_Z2);
> + *val = tsc2007_calculate_resistance(tsc, &tc);
> + break;
> + }
> + case 6:
> + *val = tsc2007_is_pen_down(tsc);
> + break;
> + case 7:
> + *val = tsc2007_xfer(tsc,
> + (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
> + break;
> + case 8:
> + *val = tsc2007_xfer(tsc,
> + (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
> + break;
> + }
> +
> + /* Prepare for next touch reading - power down ADC, enable PENIRQ */
> + tsc2007_xfer(tsc, PWRDOWN);
> +
> + mutex_unlock(&tsc->mlock);
> +
> + ret = IIO_VAL_INT;
> +
> + return ret;
> +}
> +
> +static const struct iio_info tsc2007_iio_info = {
> + .read_raw = tsc2007_read_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static int tsc2007_alloc(struct i2c_client *client, struct tsc2007 **ts,
> + struct input_dev **input_dev)
> +{
> + int err;
> + struct iio_dev *indio_dev;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*ts));
Instead of doing this to reduce the delta between versions make
iio_priv a struct tsc2007 **
That is have a single pointer in there and do your allocation of struct
tsc2007 separately.
Having doing that, you can have this CONFIG_IIO block as just
doing the iio stuff with the input elements pulled back into the main
probe function.
Then define something like
iio_configure (stubbed to nothing if no IIO)
and
iio_unconfigure (also stubbed to nothing if no IIO).
A couple of additions in the header to make it all work
(the struct tsc2007 and tsc2007_xfer() + a few of the
register defines..
Nothing big and gets all the CONFIG_IIO into some really
obvious stubbing out in the header.
> + if (!indio_dev) {
> + dev_err(&client->dev, "iio_device_alloc failed\n");
> + return -ENOMEM;
> + }
> +
> + *ts = iio_priv(indio_dev);
> +
> + *input_dev = devm_input_allocate_device(&client->dev);
> + if (!*input_dev)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, *ts);
> + (*ts)->indio = indio_dev;
> +
> + indio_dev->name = "tsc2007";
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->info = &tsc2007_iio_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->channels = tsc2007_iio_channel;
> + indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
> +
> + err = iio_device_register(indio_dev);
> + if (err < 0) {
> + dev_err(&client->dev, "iio_device_register() failed: %d\n",
> + err);
> + return err;
> + }
> +
> + return 0;
> +}
> +
> +#define tsc2007_iio_device_unregister(ts) iio_device_unregister(ts->indio)
> +
> +#else /* CONFIG_IIO */
> +
> +static int tsc2007_alloc(struct i2c_client *client, struct tsc2007 **ts,
> + struct input_dev **input_dev)
> +{
> + int err;
> +
> + *ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
> + if (!*ts)
> + return -ENOMEM;
> +
> + *input_dev = devm_input_allocate_device(&client->dev);
> + if (!*input_dev)
> + return -ENOMEM;
> +
> + i2c_set_clientdata(client, *ts);
> +
> + return 0;
> +}
> +
> +#define tsc2007_iio_device_unregister(ts) /* not needed */
That's rather ugly and fragile. I'd stub it out as an actual function
with no content and let the compiler drop it.
> +
> +#endif /* CONFIG_IIO */
> +
> #ifdef CONFIG_OF
> static int tsc2007_get_pendown_state_gpio(struct device *dev)
> {
> @@ -459,20 +623,15 @@ static int tsc2007_probe(struct i2c_client *client,
> I2C_FUNC_SMBUS_READ_WORD_DATA))
> return -EIO;
>
> - ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
> - if (!ts)
> - return -ENOMEM;
> -
> - input_dev = devm_input_allocate_device(&client->dev);
> - if (!input_dev)
> - return -ENOMEM;
> -
> - i2c_set_clientdata(client, ts);
> + err = tsc2007_alloc(client, &ts, &input_dev);
> + if (err < 0)
> + return err;
>
> ts->client = client;
> ts->irq = client->irq;
> ts->input = input_dev;
> init_waitqueue_head(&ts->wait);
> + mutex_init(&ts->mlock);
>
> snprintf(ts->phys, sizeof(ts->phys),
> "%s/input0", dev_name(&client->dev));
> @@ -543,6 +702,7 @@ static int tsc2007_probe(struct i2c_client *client,
> if (err < 0) {
> dev_err(&client->dev,
> "Failed to setup chip: %d\n", err);
> + tsc2007_iio_device_unregister(ts);
> return err; /* usually, chip does not respond */
> }
>
> @@ -556,6 +716,14 @@ static int tsc2007_probe(struct i2c_client *client,
> return 0;
> }
>
> +static int tsc2007_remove(struct i2c_client *client)
> +{
> + struct tsc2007 *ts = i2c_get_clientdata(client);
> + input_unregister_device(ts->input);
> + tsc2007_iio_device_unregister(ts);
> + return 0;
> +}
> +
> static const struct i2c_device_id tsc2007_idtable[] = {
> { "tsc2007", 0 },
> { }
> @@ -578,6 +746,7 @@ static struct i2c_driver tsc2007_driver = {
> },
> .id_table = tsc2007_idtable,
> .probe = tsc2007_probe,
> + .remove = tsc2007_remove,
> };
>
> module_i2c_driver(tsc2007_driver);
>
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