On 23/10/16 19:34, H. Nikolaus Schaller wrote:
> Hi Jonathan,
>
>> Am 23.10.2016 um 11:57 schrieb H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>:
>>
>> 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);--
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