Hi Adam, Am Donnerstag, 4. Mai 2023, 14:00:08 CEST schrieb Adam Ford: > On Thu, May 4, 2023 at 4:21 AM Alexander Stein > > <alexander.stein@xxxxxxxxxxxxxxx> wrote: > > Am Dienstag, 2. Mai 2023, 03:07:55 CEST schrieb Adam Ford: > > > Make the pll-clock-frequency optional. If it's present, use it > > > to maintain backwards compatibility with existing hardware. If it > > > is absent, read clock rate of "sclk_mipi" to determine the rate. > > > > > > Signed-off-by: Adam Ford <aford173@xxxxxxxxx> > > > Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx> > > > --- > > > > > > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++++++-- > > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c > > > b/drivers/gpu/drm/bridge/samsung-dsim.c index bf4b33d2de76..2dc02a9e37c0 > > > 100644 > > > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > > > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > > > @@ -1726,12 +1726,20 @@ static int samsung_dsim_parse_dt(struct > > > samsung_dsim *dsi) { > > > > > > struct device *dev = dsi->dev; > > > struct device_node *node = dev->of_node; > > > > > > + struct clk *pll_clk; > > > > > > int ret; > > > > > > ret = samsung_dsim_of_read_u32(node, > > > "samsung,pll-clock-frequency", > > > > > > &dsi->pll_clk_rate); > > > > > > - if (ret < 0) > > > - return ret; > > > + > > > + /* If it doesn't exist, read it from the clock instead of failing > > > */ > > > + if (ret < 0) { > > > + pll_clk = devm_clk_get(dev, "sclk_mipi"); > > > + if (!IS_ERR(pll_clk)) > > > + dsi->pll_clk_rate = clk_get_rate(pll_clk); > > > + else > > > + return PTR_ERR(pll_clk); > > > + } > > > > Now that 'samsung,pll-clock-frequency' is optional the error in > > samsung_dsim_of_read_u32() should be changed. Otherwise you will get > > > > > /soc@0/bus@32c00000/dsi@32e10000: failed to get 'samsung,pll-clock- > > > > frequency' property > > I'll change the message from err to info with a message that reads "no > samsung,pll-clock-frequency, using pixel clock" > > Does that work? Having just a info is totally fine with me. Thanks. Although your suggested message somehow implies (to me) using pixel clock is just a fallback. I'm a bit concerned some might think "samsung,pll-clock- frequency" should be provided in DT. But this might just be me. Best regards, Alexander > adam > > > Best regards, > > Alexander > > > > > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock- > > > > frequency", > > > > > &dsi->burst_clk_rate); > > > > -- > > TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany > > Amtsgericht München, HRB 105018 > > Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider > > http://www.tq-group.com/ -- TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany Amtsgericht München, HRB 105018 Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider http://www.tq-group.com/