On 2023-02-21 18:48, Andy Shevchenko wrote:
On Tue, Feb 21, 2023 at 05:10:00PM +0100, Robin van der Gracht wrote:
On 2023-02-21 14:40, Andy Shevchenko wrote:
> On Tue, Feb 21, 2023 at 03:33:06PM +0200, Andy Shevchenko wrote:
> > Switching to use device_get_match_data() helps getting of
> > i2c_of_match_device() API.
...
> > - id = i2c_of_match_device(dev->driver->of_match_table, client);
> > - if (id)
> > - priv->type = (uintptr_t)id->data;
> > + priv->type = (uintptr_t)device_get_match_data(dev);
>
> Looking closer the I²C ID table should provide DISP_MATRIX to keep
> default and this needs to be not dropped.
>
> So, the question is what to do with unknown type then, return -EINVAL
> from probe()?
If you leave out your addition of the DISP_UNKNOWN type, the default
type
will be DISP_MATRIX if no match is found, which is as it is now.
In that case the following change should suffice:
@@ -713,7 +715,6 @@ static int ht16k33_seg_probe(struct device *dev,
struct
ht16k33_priv *priv,
static int ht16k33_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
- const struct of_device_id *id;
struct ht16k33_priv *priv;
uint32_t dft_brightness;
int err;
@@ -728,9 +729,8 @@ static int ht16k33_probe(struct i2c_client
*client)
return -ENOMEM;
priv->client = client;
- id = i2c_of_match_device(dev->driver->of_match_table, client);
- if (id)
- priv->type = (uintptr_t)id->data;
+ priv->type = (uintptr_t)device_get_match_data(dev);
+
i2c_set_clientdata(client, priv);
err = ht16k33_initialize(priv);
Or do you think falling back to DISP_MATRIX if no match is found is
wrong?
First of all, the I²C ID table should actually use DISP_MATRIX.
Second, there are two points:
- It would be nice to check if the OF ID table doesn't provide a
setting
(shouldn't we try I²C ID table and then, if still nothing, bail out?)
- The I²C ID table can be extended in the future with another entry
which
may want to have different default
For my understanding, please correct me if I'm wrong;
For all methods of instantiation during ht16k33 probe,
i2c_of_match_device()
matches the compatible strings in the OF ID table due to a call to
i2c_of_match_device_sysfs().
device_get_match_data() only matches the compatible strings in the OF ID
table for devicetree instantiation because of_match_device() won't match
is there is no actual of_node.
So with only device_get_match_data() and a non devicetree instantiation,
priv->type will always be (uintptr_t)NULL = 0 = DISP_MATRIX.
Which effectively breaks i.e. user-space instantiation for other display
types which now do work due to i2c_of_match_device().
(so my suggestion above is not sufficient).
Are you proposing extending and searching the I2C ID table to work
around that?
Kind regards,
--
Robin van der Gracht
Protonic Holland
Factorij 36
1689AL Zwaag
+31 (0)229 212928
https://www.protonic.nl
