[PATCH] drm: bridge: it66121: Extend match support for OF tables

[Biju Das]

Hi Laurent Pinchart,

Thanks for the feedback.

> Subject: Re: [PATCH] drm: bridge: it66121: Extend match support for OF
> tables
> 
> Hi Biju,
> 
> Thank you for the patch.
> 
> On Sun, Aug 13, 2023 at 09:05:20AM +0100, Biju Das wrote:
> > The driver has OF match table, still it uses ID lookup table for
> > retrieving match data. Replace ID look up with i2c_get_match_data()
> > for retrieving OF/ACPI/I2C match data by adding similar match data for
> > OF table.
> 
> Could you please explain in the commit message *why* this is desired ?

Currently the driver is working on the assumption that a
I2C device registered via OF will always match a legacy
I2C device ID. The correct approach is to have an
OF device ID table using of_device_match_data()/device_match_data()/
I2c_get_match_data() if the devices are registered via OF.

Basically, it is fixing

Fixes: 9a9f4a01bdae ("drm: bridge: it66121: Move VID/PID to new it66121_chip_info structure")

But i2c_get_match_data() is recently introduced.

Maybe one patch with fixes tag using of_device_get_match_data and
ID lookup for retrieving match data from OF/I2C tables

and another patch to simplify using i2c_get_match_data() by replacing of_device_get_match_data and ID lookup.

> 
> > While at it, drop unused local varibale id from probe().
> 
> I'd drop this sentence, that's not a "while at it" change but an integral
> part of this patch.

Agreed.

Cheers,
Biju

> 
> > Signed-off-by: Biju Das <biju.das.jz at bp.renesas.com>
> > ---
> >  This patch is only compile tested.
> > ---
> >  drivers/gpu/drm/bridge/ite-it66121.c | 17 ++++++++---------
> >  1 file changed, 8 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/ite-it66121.c
> > b/drivers/gpu/drm/bridge/ite-it66121.c
> > index 466641c77fe9..a80246ef4ffe 100644
> > --- a/drivers/gpu/drm/bridge/ite-it66121.c
> > +++ b/drivers/gpu/drm/bridge/ite-it66121.c
> > @@ -1501,7 +1501,6 @@ static const char * const it66121_supplies[] = {
> >
> >  static int it66121_probe(struct i2c_client *client)  {
> > -	const struct i2c_device_id *id = i2c_client_get_device_id(client);
> >  	u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
> >  	struct device_node *ep;
> >  	int ret;
> > @@ -1523,7 +1522,7 @@ static int it66121_probe(struct i2c_client
> > *client)
> >
> >  	ctx->dev = dev;
> >  	ctx->client = client;
> > -	ctx->info = (const struct it66121_chip_info *) id->driver_data;
> > +	ctx->info = i2c_get_match_data(client);
> >
> >  	of_property_read_u32(ep, "bus-width", &ctx->bus_width);
> >  	of_node_put(ep);
> > @@ -1609,13 +1608,6 @@ static void it66121_remove(struct i2c_client
> *client)
> >  	mutex_destroy(&ctx->lock);
> >  }
> >
> > -static const struct of_device_id it66121_dt_match[] = {
> > -	{ .compatible = "ite,it66121" },
> > -	{ .compatible = "ite,it6610" },
> > -	{ }
> > -};
> > -MODULE_DEVICE_TABLE(of, it66121_dt_match);
> > -
> >  static const struct it66121_chip_info it66121_chip_info = {
> >  	.id = ID_IT66121,
> >  	.vid = 0x4954,
> > @@ -1628,6 +1620,13 @@ static const struct it66121_chip_info
> it6610_chip_info = {
> >  	.pid = 0x0611,
> >  };
> >
> > +static const struct of_device_id it66121_dt_match[] = {
> > +	{ .compatible = "ite,it66121", &it66121_chip_info },
> > +	{ .compatible = "ite,it6610", &it6610_chip_info },
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, it66121_dt_match);
> > +
> >  static const struct i2c_device_id it66121_id[] = {
> >  	{ "it66121", (kernel_ulong_t) &it66121_chip_info },
> >  	{ "it6610", (kernel_ulong_t) &it6610_chip_info },
> 
> --
> Regards,
> 
> Laurent Pinchart