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. > > >Add a disable-quad-mode property in devicetree that platform can use it to > >override the quad mode status parsed from BFPT to use write protection. > > > >[1] > >https://www.elm-tech.com/ja/products/spi-flash-memory/gd25lq64/gd25lq64.pdf > > should be a link on the vendor Homepage if possible. Right, https://www.gigadevice.com.cn/Public/Uploads/uploadfile/files/20220714/DS-00012-GD25LQ64C-Rev3.4.pdf is a more proper datasheet source. The QE description is also in page 13. > > -michael >