Hi Dmitry,
On Wed, Jul 03, 2024 at 01:47:58PM -0700, Dmitry Torokhov wrote:
> Hi Charles,
>
> On Tue, Jun 18, 2024 at 04:44:53PM +0800, Charles Wang wrote:
> > This patch introduces a new driver to support the Goodix GT7986U
> > touch controller. This device is not compatible with Microsoft's
> > HID-over-SPI protocol and therefore needs to implement its own
> > flavor. The data reported is packaged according to the HID
> > protocol but uses SPI for communication to improve speed. This
> > enables the device to transmit not only coordinate data but also
> > corresponding raw data that can be accessed by user-space programs
> > through the hidraw interface. The raw data can be utilized for
> > functions like palm rejection, thereby improving the touch experience.
> >
> > Key features:
> > - Device connection confirmation and initialization
> > - IRQ-based event reporting to the input subsystem
> > - Support for HIDRAW operations (GET_REPORT and SET_REPORT)
>
> This looks reasonable good, so:
>
> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
>
> A couple of suggestions/nits below:
>
> > +static int goodix_spi_probe(struct spi_device *spi)
> > +{
> > + struct device *dev = &spi->dev;
> > + struct goodix_ts_data *ts;
> > + int error;
> > +
> > + /* init spi_device */
> > + spi->mode = SPI_MODE_0;
> > + spi->bits_per_word = 8;
> > + error = spi_setup(spi);
> > + if (error)
> > + return error;
> > +
> > + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
> > + if (!ts)
> > + return -ENOMEM;
> > +
>
> If you do:
>
> ts->event_buf = devm_kmalloc(dev, <some nominal size>, GFP_KERNEL);
>
> here and use devm_krealloc() once you figure the true size of event
> buffer you can stop calling kfree() by hand on remove.
>
Ack,
> > + mutex_init(&ts->hid_request_lock);
> > + spi_set_drvdata(spi, ts);
> > + ts->spi = spi;
> > + ts->dev = dev;
> > + 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 request reset gpio\n");
> > +
> > + error = device_property_read_u32(dev, "goodix,hid-report-addr",
> > + &ts->hid_report_addr);
> > + if (error)
> > + return dev_err_probe(dev, error,
> > + "failed get hid report addr\n");
> > +
> > + error = goodix_dev_confirm(ts);
> > + if (error)
> > + return error;
> > +
> > + /* Waits 150ms for firmware to fully boot */
> > + msleep(GOODIX_NORMAL_RESET_DELAY_MS);
> > +
> > + error = goodix_hid_init(ts);
> > + if (error) {
> > + dev_err(dev, "failed init hid device");
> > + return error;
> > + }
> > +
> > + error = devm_request_threaded_irq(&ts->spi->dev, ts->spi->irq,
> > + NULL, goodix_hid_irq, IRQF_ONESHOT,
> > + "goodix_spi_hid", ts);
> > + if (error) {
> > + dev_err(ts->dev, "could not register interrupt, irq = %d, %d",
> > + ts->spi->irq, error);
> > + goto err_destroy_hid;
> > + }
> > +
> > + return 0;
> > +
> > +err_destroy_hid:
> > + hid_destroy_device(ts->hid);
> > + return error;
> > +}
> > +
> > +static void goodix_spi_remove(struct spi_device *spi)
> > +{
> > + struct goodix_ts_data *ts = spi_get_drvdata(spi);
> > +
> > + disable_irq(spi->irq);
> > + hid_destroy_device(ts->hid);
> > + kfree(ts->event_buf);
> > +}
> > +
> > +static void goodix_spi_shutdown(struct spi_device *spi)
> > +{
> > + struct goodix_ts_data *ts = spi_get_drvdata(spi);
> > +
> > + disable_irq(spi->irq);
> > + hid_destroy_device(ts->hid);
>
> Do we really need shutdown() method? It is very rarely that it is
> needed.
>
After testing on the machine, we found that this method is only invoked
during system shutdown. Since the device doesn't require any special
operations at shutdown, so I think it can be removed.
> > +}
> > +
> > +static int goodix_spi_set_power(struct goodix_ts_data *ts, int power_state)
> > +{
> > + u8 power_control_cmd[] = {0x00, 0x00, 0x00, 0x87, 0x02, 0x00, 0x08};
> > + int error;
> > +
> > + /* value 0 for power on, 1 for power sleep */
> > + power_control_cmd[5] = power_state;
> > +
> > + guard(mutex)(&ts->hid_request_lock);
> > + error = goodix_spi_write(ts, ts->hid_report_addr, power_control_cmd,
> > + sizeof(power_control_cmd));
> > + if (error) {
> > + dev_err(ts->dev, "failed set power mode: %s",
> > + power_state == GOODIX_SPI_POWER_ON ? "on" : "sleep");
> > + return error;
> > + }
> > + return 0;
> > +}
> > +
> > +static int goodix_spi_suspend(struct device *dev)
> > +{
> > + struct goodix_ts_data *ts = dev_get_drvdata(dev);
> > + int error;
> > +
> > + error = goodix_spi_set_power(ts, GOODIX_SPI_POWER_SLEEP);
> > + disable_irq(ts->spi->irq);
>
> Can disable_irq() be called first?
>
Ack, calling this first seems better.
Thanks,
Charles
