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spi: rspi: Do not set SPCR_SPE in qspi_set_config_register()

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The R-Car Gen2 Hardware User Manual Rev. 2.00 states:

    If the master/slave mode select bit (MSTR) is modified while the SPI
    function enable bit (SPE) is set to 1 (that is, this module is
    enabled), the subsequent operation cannot be guaranteed.

Hence do not set SPCR_SPE when setting SPCR_MSTR, just like the
.set_config_register() implementations for other RSPI variants do.

Note that when booted from QSPI, the boot loader will have set SPCR_MSTR
already, hence usually the bit is never modified by the Linux driver.

Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Geert Uytterhoeven 2017-12-07 11:09:21 +01:00 committed by Mark Brown
parent 4fbd8d194f
commit b458a3490e
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1 changed files with 2 additions and 2 deletions
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4
drivers/spi/spi-rspi.c
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@ -377,8 +377,8 @@ static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
/* Sets SPCMD */
rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
/* Enables SPI function in master mode */
rspi_write8(rspi, SPCR_SPE | SPCR_MSTR, RSPI_SPCR);
/* Sets RSPI mode */
rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
return 0;
}