Re: [PATCH v10 3/3] Input: Add TouchNetix axiom i2c touchscreen driver

[Kamel BOUHARA <kamel.bouhara@xxxxxxxxxxx>]

Le 2024-04-19 11:28, Marco Felsch a écrit :
> Hi Kamel,

Hi,

> thank you for the patch. Again just a rough review.
>
> On 24-04-19, Kamel Bouhara wrote:
> > Add a new driver for the TouchNetix's axiom family of
> > touchscreen controllers. This driver only supports i2c
> > and can be later adapted for SPI and USB support.
> >
> > Signed-off-by: Kamel Bouhara <kamel.bouhara@xxxxxxxxxxx>
> > ---
>
> ...
>
> > +static int axiom_i2c_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct input_dev *input_dev;
> > +	struct axiom_data *ts;
> > +	u32 poll_interval;
> > +	int target;
> > +	int error;
> > +
> > +	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > +	if (!ts)
> > +		return -ENOMEM;
> > +
> > +	i2c_set_clientdata(client, ts);
> > +	ts->client = client;
> > +	ts->dev = dev;
> > +
> > +	ts->regmap = devm_regmap_init_i2c(client, &axiom_i2c_regmap_config);
> > +	error = PTR_ERR_OR_ZERO(ts->regmap);
> > +	if (error) {
> > +		dev_err(dev, "Failed to initialize regmap: %d\n", error);
> > +		return error;
> > +	}
> > +
> > +	ts->vddi = devm_regulator_get(dev, "VDDI");
>
> This does not match the dt-bindings.
>
> > +	if (IS_ERR(ts->vddi))
> > +		return dev_err_probe(&client->dev, PTR_ERR(ts->vddi),
> > +				     "Failed to enable VDDI regulator\n");
> > +
> > +	ts->vdda = devm_regulator_get(dev, "VDDA");
>
> Here as well.
>
> > +	if (IS_ERR(ts->vdda))
> > +		return dev_err_probe(&client->dev, PTR_ERR(ts->vdda),
> > +				     "Failed to enable VDDA regulator\n");
>
> Now we handle it as always but..
>
> > +	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", 
> > GPIOD_OUT_HIGH);
> > +	if (IS_ERR(ts->reset_gpio))
> > +		return dev_err_probe(dev, PTR_ERR(ts->reset_gpio), "failed to get 
> > reset GPIO\n");
> > +
> > +	if (ts->reset_gpio)
> > +		axiom_reset(ts->reset_gpio);
> > +	else
> > +		msleep(AXIOM_STARTUP_TIME_MS);
>
> still the reset is useless since you never enabled the regulators. So
> either use devm_regulator_get_enable() or you do the enable/disable
> separate via regulator_enable()/disable(). If there are no strict
> enablement restrictions like orders and timings you could also make use
> of the regulator_bulk API (e.g. devm_regulator_bulk_get_enable).

I will just go with the devm_regulator_get_enable() solution in v11, 
regulator have to be enabled
before reset is asserted here.

Thanks again!

Kamel

> Regards,
>   Marco
>
> > +
> > +	error = axiom_discover(ts);
> > +	if (error)
> > +		return dev_err_probe(dev, error, "Failed touchscreen discover\n");
> > +
> > +	input_dev = devm_input_allocate_device(ts->dev);
> > +	if (!input_dev)
> > +		return -ENOMEM;
> > +
> > +	input_dev->name = "TouchNetix axiom Touchscreen";
> > +	input_dev->phys = "input/axiom_ts";
> > +
> > +	input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, 65535, 0, 0);
> > +	input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0, 65535, 0, 0);
> > +	input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE, 0, MT_TOOL_MAX, 0, 
> > 0);
> > +	input_set_abs_params(input_dev, ABS_MT_DISTANCE, 0, 127, 0, 0);
> > +	input_set_abs_params(input_dev, ABS_MT_PRESSURE, 0, 127, 0, 0);
> > +
> > +	touchscreen_parse_properties(input_dev, true, &ts->prop);
> > +
> > +	/* Registers the axiom device as a touchscreen instead of a mouse 
> > pointer */
> > +	error = input_mt_init_slots(input_dev, AXIOM_U41_MAX_TARGETS, 
> > INPUT_MT_DIRECT);
> > +	if (error)
> > +		return error;
> > +
> > +	/* Enables the raw data for up to 4 force channels to be sent to the 
> > input subsystem */
> > +	set_bit(EV_REL, input_dev->evbit);
> > +	set_bit(EV_MSC, input_dev->evbit);
> > +	/* Declare that we support "RAW" Miscellaneous events */
> > +	set_bit(MSC_RAW, input_dev->mscbit);
> > +
> > +	ts->input_dev = input_dev;
> > +	input_set_drvdata(ts->input_dev, ts);
> > +
> > +	/* Ensure that all reports are initialised to not be present. */
> > +	for (target = 0; target < AXIOM_U41_MAX_TARGETS; target++)
> > +		ts->targets[target].state = AXIOM_TARGET_STATE_NOT_PRESENT;
> > +
> > +	error = devm_request_threaded_irq(dev, client->irq, NULL,
> > +					  axiom_irq, IRQF_ONESHOT, dev_name(dev), ts);
> > +	if (error) {
> > +		dev_info(dev, "Request irq failed, falling back to polling mode");
> > +
> > +		error = input_setup_polling(input_dev, axiom_i2c_poll);
> > +		if (error)
> > +			return dev_err_probe(ts->dev, error, "Unable to set up polling 
> > mode\n");
> > +
> > +		if (!device_property_read_u32(ts->dev, "poll-interval", 
> > &poll_interval))
> > +			input_set_poll_interval(input_dev, poll_interval);
> > +		else
> > +			input_set_poll_interval(input_dev, POLL_INTERVAL_DEFAULT_MS);
> > +	}
> > +
> > +	return input_register_device(input_dev);
> > +}
> > +
> > +static const struct i2c_device_id axiom_i2c_id_table[] = {
> > +	{ "ax54a" },
> > +	{ },
> > +};
> > +MODULE_DEVICE_TABLE(i2c, axiom_i2c_id_table);
> > +
> > +static const struct of_device_id axiom_i2c_of_match[] = {
> > +	{ .compatible = "touchnetix,ax54a", },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, axiom_i2c_of_match);
> > +
> > +static struct i2c_driver axiom_i2c_driver = {
> > +	.driver = {
> > +		   .name = "axiom",
> > +		   .of_match_table = axiom_i2c_of_match,
> > +	},
> > +	.id_table = axiom_i2c_id_table,
> > +	.probe = axiom_i2c_probe,
> > +};
> > +module_i2c_driver(axiom_i2c_driver);
> > +
> > +MODULE_AUTHOR("Bart Prescott <bartp@xxxxxxxxxxxxxx>");
> > +MODULE_AUTHOR("Pedro Torruella <pedro.torruella@xxxxxxxxxxxxxx>");
> > +MODULE_AUTHOR("Mark Satterthwaite 
> > <mark.satterthwaite@xxxxxxxxxxxxxx>");
> > +MODULE_AUTHOR("Hannah Rossiter <hannah.rossiter@xxxxxxxxxxxxxx>");
> > +MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@xxxxxxxxxxx>");
> > +MODULE_DESCRIPTION("TouchNetix axiom touchscreen I2C bus driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.25.1

--
--
Kamel Bouhara, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com