[PATCH v2 1/2] mtd: spi-nor: add driver for NXP SPI Flash Interface (SPIFI)
Ezequiel Garcia
ezequiel at vanguardiasur.com.ar
Thu Jun 4 08:05:18 PDT 2015
Joachim,
I tested the driver and found an issue with it.
On 05/31/2015 06:06 PM, Joachim Eastwood wrote:
> +
> + spifi->mtd.priv = &spifi->nor;
> + spifi->nor.mtd = &spifi->mtd;
> + spifi->nor.dev = spifi->dev;
> + spifi->nor.priv = spifi;
> + spifi->nor.read = nxp_spifi_read;
> + spifi->nor.write = nxp_spifi_write;
> + spifi->nor.erase = nxp_spifi_erase;
> + spifi->nor.read_reg = nxp_spifi_read_reg;
> + spifi->nor.write_reg = nxp_spifi_write_reg;
> +
> + ret = of_modalias_node(np, modalias, sizeof(modalias));
> + if (ret < 0) {
> + dev_err(spifi->dev, "unable to get device modalias\n");
> + return ret;
> + }
> +
> + /*
> + * The first read on a hard reset isn't reliable so do a
> + * dummy read of the id before calling spi_nor_scan().
> + * The reason for this problem is unknown.
> + *
> + * The official NXP spifilib uses more or less the same
> + * workaround that is applied here by reading the device
> + * id multiple times.
> + */
> + nxp_spifi_dummy_id_read(&spifi->nor);
> +
Actually, I think there's an issue here. See how m25p80 deals
with modalias:
[..]
else if (!strcmp(spi->modalias, "spi-nor"))
flash_name = NULL; /* auto-detect */
else
flash_name = spi->modalias;
ret = spi_nor_scan(nor, flash_name, mode);
if (ret)
return ret;
I think the "auto-detect" quirk is really needed, or you are will
otherwise fail to probe with the generic "jedec,spi-nor" compatible
string.
Notice that the binding specifies the chip-specific compatible
as optional (it says _May_):
- compatible : May include a device-specific string consisting of the
manufacturer and name of the chip.
> + ret = spi_nor_scan(&spifi->nor, modalias, flash_read);
> + if (ret) {
> + dev_err(spifi->dev, "device scan failed\n");
> + return ret;
> + }
--
Ezequiel Garcia, VanguardiaSur
www.vanguardiasur.com.ar
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