Hi Sebastian,
On Thu, Nov 07, 2019 at 07:10:10PM +0100, 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.
>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
> ---
> drivers/input/touchscreen/exc3000.c | 136 ++++++++++++++++++++++++++++
> 1 file changed, 136 insertions(+)
>
> diff --git a/drivers/input/touchscreen/exc3000.c b/drivers/input/touchscreen/exc3000.c
> index 7d695022082c..4c9f132629b9 100644
> --- a/drivers/input/touchscreen/exc3000.c
> +++ b/drivers/input/touchscreen/exc3000.c
> @@ -41,6 +41,11 @@ struct exc3000_data {
> struct touchscreen_properties prop;
> struct timer_list timer;
> u8 buf[2 * EXC3000_LEN_FRAME];
> + char model[11];
> + char fw_version[6];
> + struct completion wait_event;
> + struct mutex query_lock;
> + int query_result;
> };
>
> static void exc3000_report_slots(struct input_dev *input,
> @@ -121,6 +126,35 @@ static int exc3000_read_data(struct i2c_client *client,
> return 0;
> }
>
> +static void exc3000_query_interrupt(struct exc3000_data *data)
> +{
> + u8 *buf = data->buf;
> + int err;
> +
> + data->query_result = 0;
> +
> + err = i2c_master_recv(data->client, buf, EXC3000_LEN_FRAME);
> + if (err < 0) {
> + data->query_result = err;
> + goto out;
> + }
> +
> + if (buf[0] == 0x42 && buf[4] == 'E') {
> + memcpy(data->model, buf+5, 10);
> + data->model[10] = '\0';
> + goto out;
> + } else if (buf[0] == 0x42 && buf[4] == 'D') {
> + memcpy(data->fw_version, buf+5, 5);
> + data->fw_version[5] = '\0';
> + goto out;
> + }
> +
> + data->query_result = -EPROTO;
> +
> +out:
> + complete(&data->wait_event);
> +}
> +
> static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
> {
> struct exc3000_data *data = dev_id;
> @@ -129,6 +163,11 @@ static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
> int slots, total_slots;
> int error;
>
> + if (mutex_is_locked(&data->query_lock)) {
> + exc3000_query_interrupt(data);
> + goto out;
> + }
> +
> error = exc3000_read_data(data->client, buf, &total_slots);
> if (error) {
> /* Schedule a timer to release "stuck" contacts */
> @@ -156,12 +195,92 @@ static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static int exc3000_get_fw_version(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(fw_version, S_IRUGO, exc3000_get_fw_version, NULL);
> +
> +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 exc3000_get_model_sysfs(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct exc3000_data *data = dev_get_drvdata(dev);
> + int err = exc3000_get_model(data);
Do we really need to re-fetch model (and firmware ID) on each access?
Can we query it as probe time and cache? This I think would simplify the
driver, as you probably would not need to hook it into the ISR. Can you
just post a read/write transaction to fetch it without waiting for
interrupt? Or, if single transaction does not work and you need to wait
for certain time for response - just add msleep() and maybe mark driver
for async probe...
Thanks.
--
Dmitry
