On Mon, Oct 17, 2016 at 8:57 AM, H. Nikolaus Schaller hns@goldelico.com wrote:

commit b98abe52fa8e ("Input: add common DT binding for touchscreens") introduced common DT bindings for touchscreens [1] and a helper function to parse the DT.

commit ed7c9870c9bc ("Input: of_touchscreen - add support for inverted / swapped axes") added another helper for parsing axis inversion and swapping and applying them to x and y coordinates.

Both helpers have been integrated to accommodate any orientation of the touch panel in relation to the LCD.

Please add the explanation of why this is a compatible change here.

A new feature is to introduce scaling the min/max ADC values to the screen size.

Sounds like a separate change.

This makes it possible to pre-calibrate the touch so that is (almost) exactly matches the LCD pixel coordinates it is glued onto. This allows to well enough operate the touch before a user space calibration step can improve the precision.

Finally, calculate_pressure has been renamed to calculate_resistance because that is what it is doing.

Signed-off-by: H. Nikolaus Schaller hns@goldelico.com

.../bindings/input/touchscreen/tsc2007.txt | 20 ++-- drivers/input/touchscreen/tsc2007.c | 120 +++++++++++++++++---- include/linux/i2c/tsc2007.h | 8 ++ 3 files changed, 118 insertions(+), 30 deletions(-)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt index ec365e1..6e9fd55 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt +++ b/Documentation/devicetree/bindings/input/touchscreen/tsc2007.txt @@ -6,6 +6,7 @@ Required properties:

• ti,x-plate-ohms: X-plate resistance in ohms.

Optional properties: +- generic touch screen properties: see touchscreen binding [2].

• gpios: the interrupt gpio the chip is connected to (trough the penirq pin). The penirq pin goes to low when the panel is touched. (see GPIO binding[1] for more details).

@@ -13,17 +14,20 @@ Optional properties: (see interrupt binding[0]).

• interrupts: (gpio) interrupt to which the chip is connected (see interrupt binding[0]).

-- ti,max-rt: maximum pressure. -- ti,fuzzx: specifies the absolute input fuzz x value.

• If set, it will permit noise in the data up to +- the value given to the fuzz
• parameter, that is used to filter noise from the event stream.

-- ti,fuzzy: specifies the absolute input fuzz y value. -- ti,fuzzz: specifies the absolute input fuzz z value. +- ti,max-rt: maximum pressure resistance above which samples are ignored

• (default: 4095).

+- ti,report-resistance: report resistance (no pressure = max_rt) instead

• of pressure (no pressure = 0).

+- ti,min-x: minimum value reported by X axis ADC (default 0). +- ti,max-x: maximum value reported by X axis ADC (default 4095). +- ti,min-y: minimum value reported by Y axis ADC (default 0). +- ti,max-y: maximum value reported by Y axis ADC (default 4095).

I thought these were going to be common? I think they should be.

Rob

• ti,poll-period: how much time to wait (in milliseconds) before reading again the
• values from the tsc2007.

• values from the tsc2007 (default 1).

+[2]: Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt

Example: &i2c1 { @@ -35,6 +39,8 @@ Example: interrupts = <0x0 0x8>; gpios = <&gpio4 0 0>; ti,x-plate-ohms = <180>;

•                   touchscreen-size-x = <640>;
  

•                   touchscreen-size-y = <480>;
            };
  
            /* ... */
  

Hi Jonathan,

Am 22.10.2016 um 20:33 schrieb Jonathan Cameron jic23@kernel.org:

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@goldelico.com

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?

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 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)); + 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 */ + +#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);

Hi,

Am 23.10.2016 um 11:24 schrieb Jonathan Cameron jic23@kernel.org:

On 22/10/16 21:46, H. Nikolaus Schaller wrote:

...

Hi Jonathan,

...

Am 22.10.2016 um 20:33 schrieb Jonathan Cameron jic23@kernel.org:

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@goldelico.com

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?

...

   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.

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?

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.

...

•   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

On 23/10/16 19:34, H. Nikolaus Schaller wrote:

Hi Jonathan,

...

Am 23.10.2016 um 11:57 schrieb H. Nikolaus Schaller hns@goldelico.com:

Hi,

...

...

+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.

Ok, I think I finally did understand how you mean this and have started to implement something.

oops. Didn't look on in my emails to get to this one!

The idea is to have one alloc function to return a struct tsc2007. This can be part of the probe function, like it is in the unpatched driver.

In case of iio this struct tsc2007 is also allocated explicitly so that a pointer can be stored in iio_priv.

This just means an additional iio_priv->ts = devm_kzalloc() in case of iio.

I have added that approach to my inlined patch and it seems to work (attached).

Sorry if I do not use the wording you would use and sometimes overlook something you have said. I feel here like moving on thin ice and doing guesswork about unspoken assumptions...

That's fine. Stuff that can appear obvious to one person is not necessarily obvious to another!

...

...

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).

This seems to work (draft attached).

...

...

A couple of additions in the header

I think you mean tsc2007.h?

Nope. A local header alongside the driver is what you want for this stuff. driver/input/tsc2007.h

This currently contains only platform data and could IMHO be eliminated if everything becomes DT.

...

...

to make it all work (the struct tsc2007 and tsc2007_xfer() + a few of the register defines..

Here it appears to me that I have to make a lot of so far private static and even static inline functions public so that I can make them stubs and call them from tsc2007_iio.c.

There will be a few.

And for having proper parameter types I have to make most private structs also public.

Yes a few of those as well.

I really like the idea to have the optional iio feature in a separate source file, but when really starting to write code, I get the impression that it introduces more problems than it solves.

And I wonder a little why it is not done for #ifdef CONFIG_OF in tsc2007.c as well. There are also two static function in some #ifdef #else # endif and not going through stubs.

Usually it is only done once a certain volume of code exists.

So is this intended to give up some static definitions?

Yes, that happens the moment you have multiple source files.

Some losses but generally end up with clean code separation. Always a trade off unfortunately. Pity we can't just insist IIO is available! Rather large to pull in for what is probable a niche use case.

Below is definitely heading in the right direction. I remember vaguely being convinced of the worth of doing this when optional code is involved! (was a good while ago now)

Jonathan

BR and thanks, Nikolaus

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c index 5e3c4bf..92da8f6 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>

Should not need this after introducing the new file. Will only be needed in the iio specific .c file.

#define TSC2007_MEASURE_TEMP0 (0x0 << 4) #define TSC2007_MEASURE_AUX (0x2 << 4) @@ -98,6 +99,9 @@ struct tsc2007 {

This will definitely need to go in the header though.

    int                     (*get_pendown_state)(struct device *);
    void                    (*clear_penirq)(void);

•   struct mutex            mlock;
  

•   void                    *private;
  

};

static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd) @@ -192,7 +196,10 @@ 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 +326,157 @@ static void tsc2007_close(struct input_dev *input_dev) tsc2007_stop(ts); }

+#ifdef CONFIG_IIO

+struct tsc2007_iio {

•   struct tsc2007 *ts;
  

Spot on.

+};

+#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_iio *iio = iio_priv(indio_dev);
  

•   struct tsc2007 *tsc = iio->ts;
  

•   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 inline int tsc2007_iio_configure(struct tsc2007 *ts) +{

•   int err;
  

•   struct iio_dev *indio_dev;
  

•   struct tsc2007_iio *iio;
  

•   indio_dev = devm_iio_device_alloc(&ts->client->dev, sizeof(struct tsc2007_iio));
  

•   if (!indio_dev) {
  

•           dev_err(&ts->client->dev, "iio_device_alloc failed\n");
  

•           return -ENOMEM;
  

•   }
  

•   iio = iio_priv(indio_dev);
  

•   iio->ts = ts;
  

•   ts->private = (void *) indio_dev;
  

•   indio_dev->name = "tsc2007";
  

•   indio_dev->dev.parent = &ts->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(&ts->client->dev, "iio_device_register() failed: %d\n",
  

•                   err);
  

•           return err;
  

•   }
  

•   return 0;
  

+}

+static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts) +{

•   struct iio_dev *indio_dev = ts->private;
  

•   iio_device_unregister(indio_dev);
  

+}

+#else /* CONFIG_IIO */

+static inline int tsc2007_iio_configure(struct tsc2007 *ts) +{

•   /* not needed */
  

+}

+static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts) +{

•   /* not needed */
  

+}

+#endif /* CONFIG_IIO */

#ifdef CONFIG_OF static int tsc2007_get_pendown_state_gpio(struct device *dev) { @@ -472,7 +630,13 @@ static int tsc2007_probe(struct i2c_client *client, ts->client = client; ts->irq = client->irq; ts->input = input_dev;

•   err = tsc2007_iio_configure(ts);
  

•   if (err < 0)
  

•           return err;
  

•   init_waitqueue_head(&ts->wait);
  

•   mutex_init(&ts->mlock);
  
    snprintf(ts->phys, sizeof(ts->phys),
             "%s/input0", dev_name(&client->dev));
  

@@ -503,8 +667,10 @@ static int tsc2007_probe(struct i2c_client *client, ts->fuzzz, 0); } else { err = tsc2007_probe_dt(client, ts);

•           if (err)
  

•           if (err) {
  

•                   tsc2007_iio_unconfigure(ts);
                    return err;
  

•           }
    }
  
    if (pdata) {
  

@@ -516,6 +682,7 @@ static int tsc2007_probe(struct i2c_client *client, dev_err(&client->dev, "Failed to register exit_platform_hw action, %d\n", err);

•                           tsc2007_iio_unconfigure(ts);
                            return err;
                    }
            }
  

@@ -533,6 +700,7 @@ static int tsc2007_probe(struct i2c_client *client, if (err) { dev_err(&client->dev, "Failed to request irq %d: %d\n", ts->irq, err);

•           tsc2007_iio_unconfigure(ts);
  

Maybe need a common unwind and use a goto to get to it.

            return err;
    }

@@ -543,6 +711,7 @@ static int tsc2007_probe(struct i2c_client *client, if (err < 0) { dev_err(&client->dev, "Failed to setup chip: %d\n", err);

•           tsc2007_iio_unconfigure(ts);
            return err;     /* usually, chip does not respond */
    }
  
  

@@ -550,12 +719,21 @@ static int tsc2007_probe(struct i2c_client *client, if (err) { dev_err(&client->dev, "Failed to register input device: %d\n", err);

•           tsc2007_iio_unconfigure(ts);
            return err;
    }
  
    return 0;
  

}

+static int tsc2007_remove(struct i2c_client *client) +{

•   struct tsc2007 *ts = i2c_get_clientdata(client);
  

•   tsc2007_iio_unconfigure(ts);
  

•   input_unregister_device(ts->input);
  

•   return 0;
  

+}

static const struct i2c_device_id tsc2007_idtable[] = { { "tsc2007", 0 }, { } @@ -578,6 +756,7 @@ static struct i2c_driver tsc2007_driver = { }, .id_table = tsc2007_idtable, .probe = tsc2007_probe,

•   .remove         = tsc2007_remove,
  

};

module_i2c_driver(tsc2007_driver);-- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

Hi Jonathan,

Am 23.10.2016 um 21:00 schrieb Jonathan Cameron jic23@kernel.org:

On 23/10/16 19:34, H. Nikolaus Schaller wrote:

...

Hi Jonathan,

...

Am 23.10.2016 um 11:57 schrieb H. Nikolaus Schaller hns@goldelico.com:

Hi,

...

...

+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.

Ok, I think I finally did understand how you mean this and have started to implement something.

oops. Didn't look on in my emails to get to this one!

...

The idea is to have one alloc function to return a struct tsc2007. This can be part of the probe function, like it is in the unpatched driver.

In case of iio this struct tsc2007 is also allocated explicitly so that a pointer can be stored in iio_priv.

This just means an additional iio_priv->ts = devm_kzalloc() in case of iio.

I have added that approach to my inlined patch and it seems to work (attached).

Sorry if I do not use the wording you would use and sometimes overlook something you have said. I feel here like moving on thin ice and doing guesswork about unspoken assumptions...

That's fine. Stuff that can appear obvious to one person is not necessarily obvious to another!

...

...

...

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).

This seems to work (draft attached).

...

...

A couple of additions in the header

I think you mean tsc2007.h?

Nope. A local header alongside the driver is what you want for this stuff. driver/input/tsc2007.h

...

This currently contains only platform data and could IMHO be eliminated if everything becomes DT.

...

...

to make it all work (the struct tsc2007 and tsc2007_xfer() + a few of the register defines..

Here it appears to me that I have to make a lot of so far private static and even static inline functions public so that I can make them stubs and call them from tsc2007_iio.c.

There will be a few.

...

And for having proper parameter types I have to make most private structs also public.

Yes a few of those as well.

...

I really like the idea to have the optional iio feature in a separate source file, but when really starting to write code, I get the impression that it introduces more problems than it solves.

And I wonder a little why it is not done for #ifdef CONFIG_OF in tsc2007.c as well. There are also two static function in some #ifdef #else # endif and not going through stubs.

Usually it is only done once a certain volume of code exists.

...

So is this intended to give up some static definitions?

Yes, that happens the moment you have multiple source files.

Some losses but generally end up with clean code separation. Always a trade off unfortunately. Pity we can't just insist IIO is available! Rather large to pull in for what is probable a niche use case.

Below is definitely heading in the right direction. I remember vaguely being convinced of the worth of doing this when optional code is involved! (was a good while ago now)

Jonathan

...

BR and thanks, Nikolaus

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c index 5e3c4bf..92da8f6 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>

Should not need this after introducing the new file. Will only be needed in the iio specific .c file.

...

#define TSC2007_MEASURE_TEMP0 (0x0 << 4) #define TSC2007_MEASURE_AUX (0x2 << 4) @@ -98,6 +99,9 @@ struct tsc2007 {

This will definitely need to go in the header though.

Now I have split the code into:

tsc2007.h (constants, structs and stubs) tsc2007_iio.c (the iio stuff) tsc2007.c (most parts of the original driver)

but I have a problem of correctly modifying the Makefile.

It currently looks like:

obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o obj-$(CONFIG_IIO) += tsc2007_iio.o

We have configured CONFIG_TOUCHSCREEN_TSC2007=m and CONFIG_IIO=y.

This obviously compiles tsc2007_iio.o into the kernel.

This means that tsc2007_iio.o references tsc2007_xfer which is part of the module.

I would like to get both linked into the module, but the iio part obviously only if CONFIG_IIO is defined (either -y or -m).

How can I define this?

Or can I define

obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o tsc2007_iio.o

and embrace all code in tsc2007_iio with a big #ifdef CONFIG_IIO so that it is compiled into an empty object file in the non-iio case?

BR and thanks, Nikolaus

On 23/10/16 10:57, H. Nikolaus Schaller wrote:

Hi,

...

Am 23.10.2016 um 11:24 schrieb Jonathan Cameron jic23@kernel.org:

On 22/10/16 21:46, H. Nikolaus Schaller wrote:

...

Hi Jonathan,

...

Am 22.10.2016 um 20:33 schrieb Jonathan Cameron jic23@kernel.org:

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@goldelico.com

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

On 10/17/2016 08:57 AM, H. Nikolaus Schaller wrote:

Fix module table so that the driver is loaded if compiled as module and requested by DT.

Signed-off-by: H. Nikolaus Schaller hns@goldelico.com

drivers/input/touchscreen/ads7846.c | 11 +++++++++++ 1 file changed, 11 insertions(+)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 400e421..9a5d84d 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -1532,6 +1532,17 @@ static int ads7846_remove(struct spi_device *spi) return 0; }

+static const struct spi_device_id ads7846_idtable[] = {

• { "tsc2046", 0 },
• { "ads7843", 0 },
• { "ads7845", 0 },
• { "ads7846", 0 },
• { "ads7873", 0 },
• { }

+};

no space needed

+MODULE_DEVICE_TABLE(spi, ads7846_idtable);

static struct spi_driver ads7846_driver = { .driver = { .name = "ads7846",

the MODULE_ALIAS below can now also be removed with this patch.