On 15/08/2023 19:21, Hsin-Yi Wang wrote: > On Tue, Aug 15, 2023 at 11:59 PM Michael Walle <michael@xxxxxxxx> wrote: >> >> Hi, >> >>> On gigadevice gd25lq64c, the quad mode is enabled after BFPT is parsed. >>> According to datasheet[1], Quad enable (QE) bit needs to be set to 0 to >>> use write protection (WP) pin. It also recommends setting default value of >>> QE to 0 to avoid a potential short issue. >> >> So you are using either dual or single io mode. Why can't you use the device tree property spi-{tx,rx}-bus-width? > > I tried setting spi-tx-bus-width and spi-rx-bus-width to either 0 or 1 > and WP still doesn't work. > For this chip, quad_enable will be set to spi_nor_sr2_bit1_quad_enable > (QER flag is BFPT_DWORD15_QER_SR2_BIT1_BUGGY)[1] > > spi_nor_write_sr_and_check() calls > spi_nor_write_16bit_sr_and_check()[2] and the function sets QE bit if > quad_enable is not NULL. > > [1] https://elixir.bootlin.com/linux/latest/source/drivers/mtd/spi-nor/sfdp.c#L575 > [2] https://elixir.bootlin.com/linux/latest/source/drivers/mtd/spi-nor/core.c#L879 > > Setting spi-{tx,rx}-bus-width still falls to this function and cases. with tx/rx bus width = 2, how quad mode is still possible? IOW, why do you need new property? You wrote here about driver, but I ask about bindings. Best regards, Krzysztof