On Sat, Jun 06, 2020 at 02:19:18PM +0800, Dongchun Zhu wrote: > On Fri, 2020-06-05 at 15:46 +0300, Andy Shevchenko wrote: > > On Fri, Jun 05, 2020 at 06:54:12PM +0800, Dongchun Zhu wrote: ... > > > + depends on I2C && VIDEO_V4L2 > > > > No compile test? > > > > Sorry? > Kconfig here is based on the current media tree master branch. > It is also what the other similar drivers from Dongwoon do. COMPILE_TEST. I dunno if it's established or not practice in media subsystem. ... > > > +/* > > > + * DW9768 requires waiting time (delay time) of t_OPR after power-up, > > > + * or in the case of PD reset taking place. > > > + */ > > > +#define DW9768_T_OPR_US 1000 > > > +#define DW9768_Tvib_MS_BASE10 (64 - 1) > > > +#define DW9768_AAC_MODE_DEFAULT 2 > > > > > +#define DW9768_AAC_TIME_DEFAULT 0x20 > > > > Hex? Why not decimal? > > > > There is one optional property 'dongwoon,aac-timing' defined in DT. > I don't know whether you have noticed that. > > 'DW9768_AAC_TIME_DEFAULT' is the value set to AACT[5:0] register. > I thought the Hex unit should be proper as it is directly written to the > Hex register. I see. I would rather put it like (BIT(6) / 2) to show explicitly that we choose half of the resolution. ... > > > + val = ((unsigned char)ret & ~mask) | (val & mask); > > > > This cast is weird. > > > > Thanks for the review, but this cast is using classical pattern from > your suggestion on OV02A10 v5: > https://patchwork.linuxtv.org/patch/59788/ > > So I wonder whether it is still required to be refined currently. > Or what would it be supposed to do for the cast? Okay, does it produce a warning w/o cast? If yes, replace it at least to be the same type as mask and val. ... > > > + for ( ; val >= 0; val -= DW9768_MOVE_STEPS) { > > > + ret = dw9768_set_dac(dw9768, val); > > > + if (ret) { > > > + dev_err(&client->dev, "I2C write fail: %d", ret); > > > + return ret; > > > + } > > > + usleep_range(move_delay_us, move_delay_us + 1000); > > > + } > > > > > > It will look more naturally in the multiplier kind of value. > > > > unsigned int steps = DIV_ROUND_UP(...); > > > > while (steps--) { > > ...(..., steps * ..._MOVE_STEPS); > > ... > > } > > > > but double check arithmetics. > > The current coding style is actually updated with reference to your > previous comments on DW9768 v3: > https://patchwork.linuxtv.org/patch/61856/ I understand, but can you consider to go further and see if the proposal works? -- With Best Regards, Andy Shevchenko
