On Fri, 9 Aug 2019 18:26:23 +0300 Tomer Maimon <tmaimon77@xxxxxxxxx> wrote: > Hi Boris, > > Thanks a lot for your comment. > > On Thu, 8 Aug 2019 at 18:32, Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > wrote: > > > On Thu, 8 Aug 2019 16:14:48 +0300 > > Tomer Maimon <tmaimon77@xxxxxxxxx> wrote: > > > > > > > + > > > +static const struct spi_controller_mem_ops npcm_fiu_mem_ops = { > > > + .exec_op = npcm_fiu_exec_op, > > > > No npcm_supports_op()? That's suspicious, especially after looking at > > the npcm_fiu_exec_op() (and the functions called from there) where the > > requested ->buswidth seems to be completely ignored... > > > > Sorry but I do not fully understand it, do you mean a support for the > buswidth? > If yes it been done in the UMA functions as follow: > > uma_cfg |= ilog2(op->cmd.buswidth); > uma_cfg |= ilog2(op->addr.buswidth) << > NPCM_FIU_UMA_CFG_ADBPCK_SHIFT; > uma_cfg |= ilog2(op->data.buswidth) << > NPCM_FIU_UMA_CFG_WDBPCK_SHIFT; > uma_cfg |= op->addr.nbytes << NPCM_FIU_UMA_CFG_ADDSIZ_SHIFT; > regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR, op->addr.val); > Hm, the default supports_op() implementation might be just fine for your use case. But there's one thing you still need to check: the number of addr cycles (or address size as you call it in this driver). Looks like your IP is limited to 4 address cycles, if I'm right, you should reject any operation that have op->addr.nbytes > 4. I also wonder if there's a limitation on the data size you can have on a single transfer. If there's one you should implement ->adjust_op() too.