On 23/10/16 10:57, H. Nikolaus Schaller wrote: > Hi, > >> Am 23.10.2016 um 11:24 schrieb Jonathan Cameron <jic23@xxxxxxxxxx>: >> >> 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). > > I hope I understand what you mean (which is an indication that the result > may be much easier to read for you but not me...). > >> 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). > > Looks as if I have to make a knot in my brain before I start to understand... > > How can I use struct iio_dev here w/o including iio.h? you aren't using it. You have a pointer to it. So it (before this definition) you have a line that says struct iio_dev; you let the compiler know such a structure exists. At that point you don't actually have to provide a definition of what is in it as long as all you use is a pointer (they are always the same size). > >>> 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. > > Sorry, but I think I do not completely understand what you mean here. > > The problem is that we need to allocate some struct tsc2007 in both cases. > But in one case managed directly by &client->dev and in the other managed > indirectly. This is why I use the private area of struct iio_dev to store > the full struct tsc2007 and not just a pointer. > No you don't need to do what you are currently doing. You need to have some means to navigate from struct iio_dev to the struct tsc2007 - that doesn't have to be because it actually is in iio_priv. You can instead put a point to it in iio_priv (and only that) and allocate it the same way in both paths (stashing a copy of the address in the pointer in iio_priv). > What I mean is: > >>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*ts)); >>> *ts = iio_priv(indio_dev); > > vs. > >>> *ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL); > > > So how can the IIO case just extend/wrap devm_kzalloc(&client->dev...) and still > be managed as well? Not relevant if you just allocate it the same way both times. > >> >> 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. > > > Is there some example driver which is doing it that way to be optionally IIO > compatible? That might be easier to understand and copy than a description. This particular combination is unusual - but it similar to how we do optional buffer or trigger support in various iio drivers. Perhaps see include/linux/iio/common/st_sensors.h and look for CONFIG_IIO_TRIGGER > >> >>> + 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. > > Well, it is a quick and dirty draft. > Should indeed better be a static (inline) function with empty body. > >>> + >>> +#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); >>> >> > > BR and thanks, > Nikolaus > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html