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Message-ID: <27amnmlm52igidlv23h3d3bvaezbdumedfkqicbtreka3llhqs@fafepduxgv43>
Date: Wed, 27 Nov 2024 10:00:21 +0100
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Sasha Finkelstein <fnkl.kernel@...il.com>
Cc: Hector Martin <marcan@...can.st>, Sven Peter <sven@...npeter.dev>,
Alyssa Rosenzweig <alyssa@...enzweig.io>, Dmitry Torokhov <dmitry.torokhov@...il.com>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>, Henrik Rydberg <rydberg@...math.org>, asahi@...ts.linux.dev,
linux-arm-kernel@...ts.infradead.org, linux-input@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, Janne Grunau <j@...nau.net>
Subject: Re: [PATCH 2/4] input: apple_z2: Add a driver for Apple Z2
touchscreens
On Tue, Nov 26, 2024 at 09:48:00PM +0100, Sasha Finkelstein wrote:
> +static int apple_z2_boot(struct apple_z2 *z2)
> +{
> + int timeout;
> +
> + enable_irq(z2->spidev->irq);
> + gpiod_direction_output(z2->reset_gpio, 0);
> + timeout = wait_for_completion_timeout(&z2->boot_irq, msecs_to_jiffies(20));
> + if (timeout == 0)
> + return -ETIMEDOUT;
> + return apple_z2_upload_firmware(z2);
> +}
> +
> +static int apple_z2_open(struct input_dev *dev)
> +{
> + struct apple_z2 *z2 = input_get_drvdata(dev);
> + int error;
> +
> + /* Reset the device on boot */
> + gpiod_direction_output(z2->reset_gpio, 1);
> + usleep_range(5000, 10000);
> + error = apple_z2_boot(z2);
> + if (error) {
> + gpiod_direction_output(z2->reset_gpio, 1);
This is less readable code. Each function should clean up its own stuff,
so if z2_boot() de-asserted the reset, then z2_boot() should clean up by
asserting again, not expecting the caller to do this.
> + disable_irq(z2->spidev->irq);
> + } else
> + z2->open = 1;
> + return error;
> +}
> +
> +static void apple_z2_close(struct input_dev *dev)
> +{
> + struct apple_z2 *z2 = input_get_drvdata(dev);
> +
> + disable_irq(z2->spidev->irq);
> + gpiod_direction_output(z2->reset_gpio, 1);
> + z2->open = 0;
> + z2->booted = 0;
> +}
> +
> +static int apple_z2_probe(struct spi_device *spi)
> +{
> + struct device *dev = &spi->dev;
> + struct apple_z2 *z2;
> + int error;
> + const char *label;
> + struct touchscreen_properties props;
> +
> + z2 = devm_kzalloc(dev, sizeof(*z2), GFP_KERNEL);
> + if (!z2)
> + return -ENOMEM;
> +
> + z2->spidev = spi;
> + init_completion(&z2->boot_irq);
> + spi_set_drvdata(spi, z2);
> +
> + z2->cs_gpio = devm_gpiod_get_index(dev, "cs", 0, 0);
> + if (IS_ERR(z2->cs_gpio)) {
> + if (PTR_ERR(z2->cs_gpio) != -ENOENT) {
> + dev_err(dev, "unable to get cs");
> + return PTR_ERR(z2->cs_gpio);
> + }
> + z2->cs_gpio = NULL;
> + }
> +
> + z2->reset_gpio = devm_gpiod_get_index(dev, "reset", 0, 0);
> + if (IS_ERR(z2->reset_gpio)) {
> + dev_err(dev, "unable to get reset");
Syntax is: return dev_err_probe, almost everywhere here.
> + return PTR_ERR(z2->reset_gpio);
> + }
> +
> + error = devm_request_threaded_irq(dev, z2->spidev->irq, NULL,
> + apple_z2_irq, IRQF_ONESHOT | IRQF_NO_AUTOEN,
> + "apple-z2-irq", spi);
> + if (error < 0) {
> + dev_err(dev, "unable to request irq");
> + return z2->spidev->irq;
> + }
> +
> + error = device_property_read_string(dev, "label", &label);
> + if (error) {
> + dev_err(dev, "unable to get device name");
> + return error;
> + }
> +
> + error = device_property_read_string(dev, "firmware-name", &z2->fw_name);
> + if (error) {
> + dev_err(dev, "unable to get firmware name");
> + return error;
> + }
> +
> + z2->cal_blob = of_get_property(dev->of_node, "apple,z2-cal-blob", &z2->cal_size);
There is no such property.
You cannot sneak undocumented properties.
> + if (!z2->cal_blob) {
> + dev_warn(dev, "unable to get calibration, precision may be degraded");
> + z2->cal_size = 0;
> + }
> +
> + z2->input_dev = devm_input_allocate_device(dev);
> + if (!z2->input_dev)
> + return -ENOMEM;
> + z2->input_dev->name = label;
> + z2->input_dev->phys = "apple_z2";
> + z2->input_dev->dev.parent = dev;
> + z2->input_dev->id.bustype = BUS_SPI;
> + z2->input_dev->open = apple_z2_open;
> + z2->input_dev->close = apple_z2_close;
> +
> + /* Allocate the axes before setting from DT */
> + input_set_abs_params(z2->input_dev, ABS_MT_POSITION_X, 0, 0, 0, 0);
> + input_set_abs_params(z2->input_dev, ABS_MT_POSITION_Y, 0, 0, 0, 0);
> + touchscreen_parse_properties(z2->input_dev, true, &props);
> + z2->y_size = props.max_y;
> + input_abs_set_res(z2->input_dev, ABS_MT_POSITION_X, 100);
> + input_abs_set_res(z2->input_dev, ABS_MT_POSITION_Y, 100);
> + input_set_abs_params(z2->input_dev, ABS_MT_WIDTH_MAJOR, 0, 65535, 0, 0);
> + input_set_abs_params(z2->input_dev, ABS_MT_WIDTH_MINOR, 0, 65535, 0, 0);
> + input_set_abs_params(z2->input_dev, ABS_MT_TOUCH_MAJOR, 0, 65535, 0, 0);
> + input_set_abs_params(z2->input_dev, ABS_MT_TOUCH_MINOR, 0, 65535, 0, 0);
> + input_set_abs_params(z2->input_dev, ABS_MT_ORIENTATION, -32768, 32767, 0, 0);
> +
> + input_set_drvdata(z2->input_dev, z2);
> +
> + error = input_mt_init_slots(z2->input_dev, 256, INPUT_MT_DIRECT);
> + if (error < 0) {
> + dev_err(dev, "unable to initialize multitouch slots");
> + return error;
> + }
> +
> + error = input_register_device(z2->input_dev);
> + if (error < 0)
> + dev_err(dev, "unable to register input device");
> +
> + return error;
> +}
> +
> +static const struct of_device_id apple_z2_of_match[] = {
> + { .compatible = "apple,z2-multitouch" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, apple_z2_of_match);
> +
> +static struct spi_device_id apple_z2_of_id[] = {
> + { .name = "j293-touchbar" },
> + { .name = "j493-touchbar" },
> + { .name = "z2-touchbar" },
You should not need all these above.
> + { .name = "z2-multitouch" },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, apple_z2_of_id);
> +
> +static struct spi_driver apple_z2_driver = {
> + .driver = {
> + .name = "apple-z2",
> + .owner = THIS_MODULE,
Drop, this is some very old code. All owners were removed ~10 or more
years ago. This suggests you took some old or poorly maintained driver
as a template, thus you duplicate all the issues we already fixed.
> + .of_match_table = of_match_ptr(apple_z2_of_match),
Drop of_match_ptr(), you have a warning here.
> + },
> + .id_table = apple_z2_of_id,
> + .probe = apple_z2_probe,
Best regards,
Krzysztof
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