Hi, On Tue, May 19, 2020 at 11:12:16PM +0200, Enric Balletbo i Serra wrote: > On 19/5/20 20:24, Sebastian Reichel wrote: > > Expose model and fw_version via sysfs. Also query the model > > in probe to make sure, that the I2C communication with the > > device works before successfully probing the driver. > > > > This is a bit complicated, since EETI devices do not have > > a sync interface. Sending the commands and directly reading > > does not work. Sending the command and waiting for some time > > is also not an option, since there might be touch events in > > the mean time. > > > > Last but not least we do not cache the results, since this > > interface can be used to check the I2C communication is still > > working as expected. > > > > Signed-off-by: Sebastian Reichel <[email protected]> > > --- > > drivers/input/touchscreen/exc3000.c | 138 +++++++++++++++++++++++++++- > > 1 file changed, 137 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/input/touchscreen/exc3000.c > > b/drivers/input/touchscreen/exc3000.c > > index 9622cba514b3..1ae758bbf627 100644 > > --- a/drivers/input/touchscreen/exc3000.c > > +++ b/drivers/input/touchscreen/exc3000.c > > @@ -24,6 +24,9 @@ > > #define EXC3000_LEN_FRAME 66 > > #define EXC3000_LEN_POINT 10 > > > > +#define EXC3000_LEN_MODEL_NAME 16 > > +#define EXC3000_LEN_FW_VERSION 16 > > + > > #define EXC3000_MT1_EVENT 0x06 > > #define EXC3000_MT2_EVENT 0x18 > > > > @@ -64,6 +67,11 @@ struct exc3000_data { > > struct touchscreen_properties prop; > > struct timer_list timer; > > u8 buf[2 * EXC3000_LEN_FRAME]; > > + struct completion wait_event; > > + struct mutex query_lock; > > + int query_result; > > + char model[EXC3000_LEN_MODEL_NAME]; > > + char fw_version[EXC3000_LEN_FW_VERSION]; > > }; > > > > static void exc3000_report_slots(struct input_dev *input, > > @@ -149,6 +157,28 @@ static int exc3000_read_data(struct exc3000_data *data, > > return 0; > > } > > > > +static int exc3000_query_interrupt(struct exc3000_data *data) > > +{ > > + u8 *buf = data->buf; > > + int err; > > + > > + err = i2c_master_recv(data->client, buf, EXC3000_LEN_FRAME); > > + if (err < 0) > > + return err; > > + > > + if (buf[0] != 0x42) > > + return -EPROTO; > > + > > + if (buf[4] == 'E') > > + strlcpy(data->model, buf+5, sizeof(data->model)); > > + else if (buf[4] == 'D') > > + strlcpy(data->fw_version, buf+5, sizeof(data->fw_version)); > > + else > > + return -EPROTO; > > + > > + return 0; > > +} > > + > > static irqreturn_t exc3000_interrupt(int irq, void *dev_id) > > { > > struct exc3000_data *data = dev_id; > > @@ -157,6 +187,12 @@ static irqreturn_t exc3000_interrupt(int irq, void > > *dev_id) > > int slots, total_slots; > > int error; > > > > + if (mutex_is_locked(&data->query_lock)) { > > + data->query_result = exc3000_query_interrupt(data); > > + complete(&data->wait_event); > > + goto out; > > + } > > + > > error = exc3000_read_data(data, buf, &total_slots); > > if (error) { > > /* Schedule a timer to release "stuck" contacts */ > > @@ -184,11 +220,94 @@ static irqreturn_t exc3000_interrupt(int irq, void > > *dev_id) > > return IRQ_HANDLED; > > } > > > > +static int fw_version_show(struct device *dev, > > + struct device_attribute *attr, char *buf) > > +{ > > + struct exc3000_data *data = dev_get_drvdata(dev); > > + static const u8 request[68] = { > > + 0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'D', 0x00 > > + }; > > + struct i2c_client *client = data->client; > > + int err; > > + > > + mutex_lock(&data->query_lock); > > + > > + data->query_result = -ETIMEDOUT; > > + reinit_completion(&data->wait_event); > > + > > + err = i2c_master_send(client, request, sizeof(request)); > > + if (err < 0) { > > + mutex_unlock(&data->query_lock); > > + return err; > > + } > > + > > + wait_for_completion_interruptible_timeout(&data->wait_event, 1*HZ); > > + mutex_unlock(&data->query_lock); > > + > > + if (data->query_result < 0) > > + return data->query_result; > > + > > + return sprintf(buf, "%s\n", data->fw_version); > > +} > > +static DEVICE_ATTR_RO(fw_version); > > + > > You should probably document the new sysfs entries, although are > self-explanatory.
I suppose I could create
Documentation/ABI/testing/sysfs-driver-input-exc3000 or is there a
better place for sysfs API documentation of input devices?
> > +static ssize_t exc3000_get_model(struct exc3000_data *data)
> > +{
> > + static const u8 request[68] = {
> > + 0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'E', 0x00
> > + };
> > + struct i2c_client *client = data->client;
> > + int err;
> > +
> > + mutex_lock(&data->query_lock);
> > + data->query_result = -ETIMEDOUT;
> > + reinit_completion(&data->wait_event);
> > +
> > + err = i2c_master_send(client, request, sizeof(request));
> > + if (err < 0) {
> > + mutex_unlock(&data->query_lock);
> > + return err;
> > + }
> > +
> > + wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
> > + mutex_unlock(&data->query_lock);
> > +
> > + return data->query_result;
> > +}
> > +
> > +static ssize_t model_show(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct exc3000_data *data = dev_get_drvdata(dev);
> > + int err = exc3000_get_model(data);
> > +
> > + if (err < 0)
> > + return err;
> > +
> > + return sprintf(buf, "%s\n", data->model);
> > +}
> > +static DEVICE_ATTR_RO(model);
> > +
> > +static struct attribute *sysfs_attrs[] = {
> > + &dev_attr_fw_version.attr,
> > + &dev_attr_model.attr,
> > + NULL
> > +};
> > +
> > +static struct attribute_group exc3000_attribute_group = {
> > + .attrs = sysfs_attrs
> > +};
> > +
> > +static const struct attribute_group *exc3000_attribute_groups[] = {
> > + &exc3000_attribute_group,
> > + NULL
> > +};
> > +
> > static int exc3000_probe(struct i2c_client *client)
> > {
> > struct exc3000_data *data;
> > struct input_dev *input;
> > - int error, max_xy;
> > + int error, max_xy, retry;
> >
> > data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
> > if (!data)
> > @@ -202,15 +321,19 @@ static int exc3000_probe(struct i2c_client *client)
> > data->info = &exc3000_info[eeti_dev_id];
> > }
> > timer_setup(&data->timer, exc3000_timer, 0);
> > + init_completion(&data->wait_event);
> > + mutex_init(&data->query_lock);
> >
> > input = devm_input_allocate_device(&client->dev);
> > if (!input)
> > return -ENOMEM;
> >
> > data->input = input;
> > + input_set_drvdata(input, data);
> >
> > input->name = data->info->name;
> > input->id.bustype = BUS_I2C;
> > + input->dev.groups = exc3000_attribute_groups;
> >
> > max_xy = data->info->max_xy;
> > input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
> > @@ -233,6 +356,19 @@ static int exc3000_probe(struct i2c_client *client)
> > if (error)
> > return error;
> >
> > + for (retry = 0; retry < 3; ++retry) {
>
> Just curious, is it known to fail and need retries?
No, but a single I²C transmission can always go bad and in that case
it makes sense to recover instead of failing to load the driver. Other
buses (e.g. PCI) handle this transparently, but I²C does not.
-- Sebastian
>
> > + error = exc3000_get_model(data);
> > + if (!error)
> > + break;
> > + dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
> > + retry + 1, error);
> > + }
> > +
> > + if (error)
> > + return error;
> > +
> > + dev_dbg(&client->dev, "TS Model: %s", data->model);
> > +
> > return 0;
> > }
> >
> >
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