On Fri, Oct 13, 2017 at 2:05 PM, Chris Packham <judge.pack...@gmail.com> wrote: > Erratum NO. FE-9144572: The device SPI interface supports frequencies of > up to 50 MHz. However, due to this erratum, when the device core clock > is 250 MHz and the SPI interfaces is configured for 50MHz SPI clock and > CPOL=CPHA=1 there might occur data corruption on reads from the SPI > device. > > Implement the workaround by setting the TMISO_SAMPLE value to 0x2 > in the timing1 register. > > Signed-off-by: Chris Packham <judge.pack...@gmail.com> > ---
I've based this as much as I can on the equivalent implementation in the Linux kernel[1], but there are differences in the u-boot spi infrastructure that means I can't be as specific when qualifying whether the workaround is needed. [1] - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/spi/spi-orion.c#n248 > > arch/arm/include/asm/arch-mvebu/spi.h | 6 ++++ > drivers/spi/kirkwood_spi.c | 62 > +++++++++++++++++++++++++++++++++-- > 2 files changed, 65 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/include/asm/arch-mvebu/spi.h > b/arch/arm/include/asm/arch-mvebu/spi.h > index 3545aed17347..1de510ea6da9 100644 > --- a/arch/arm/include/asm/arch-mvebu/spi.h > +++ b/arch/arm/include/asm/arch-mvebu/spi.h > @@ -57,6 +57,12 @@ struct kwspi_registers { > #define KWSPI_TXLSBF (1 << 13) > #define KWSPI_RXLSBF (1 << 14) > > +/* Timing Parameters 1 Register */ > +#define KW_SPI_TMISO_SAMPLE_OFFSET 6 > +#define KW_SPI_TMISO_SAMPLE_MASK (0x3 << KW_SPI_TMISO_SAMPLE_OFFSET) > +#define KW_SPI_TMISO_SAMPLE_1 (1 << KW_SPI_TMISO_SAMPLE_OFFSET) > +#define KW_SPI_TMISO_SAMPLE_2 (2 << KW_SPI_TMISO_SAMPLE_OFFSET) > + > #define KWSPI_IRQUNMASK 1 /* unmask SPI interrupt */ > #define KWSPI_IRQMASK 0 /* mask SPI interrupt */ > #define KWSPI_SMEMRDIRQ 1 /* SerMem data xfer ready irq */ > diff --git a/drivers/spi/kirkwood_spi.c b/drivers/spi/kirkwood_spi.c > index 0c6bd295cde9..7992556d49eb 100644 > --- a/drivers/spi/kirkwood_spi.c > +++ b/drivers/spi/kirkwood_spi.c > @@ -243,6 +243,16 @@ int spi_xfer(struct spi_slave *slave, unsigned int > bitlen, > > /* Here now the DM part */ > > +enum mvebu_spi_type { > + ORION_SPI, > + ARMADA_SPI, > +}; > + > +struct mvebu_spi_dev { > + enum mvebu_spi_type typ; > + bool is_errata_50mhz_ac; > +}; > + > struct mvebu_spi_platdata { > struct kwspi_registers *spireg; > }; > @@ -269,10 +279,30 @@ static int mvebu_spi_set_speed(struct udevice *bus, > uint hz) > return 0; > } > > +static void > +mvebu_spi_50mhz_ac_timing_erratum(struct udevice *bus, uint mode) > +{ > + struct mvebu_spi_platdata *plat = dev_get_platdata(bus); > + struct kwspi_registers *reg = plat->spireg; > + u32 data = readl(®->timing1); > + > + data &= ~KW_SPI_TMISO_SAMPLE_MASK; > + > + if (CONFIG_SYS_TCLK == 250000000 && > + mode & SPI_CPOL && > + mode & SPI_CPHA) > + data |= KW_SPI_TMISO_SAMPLE_2; > + else > + data |= KW_SPI_TMISO_SAMPLE_1; > + > + writel(data, ®->timing1); > +} > + > static int mvebu_spi_set_mode(struct udevice *bus, uint mode) > { > struct mvebu_spi_platdata *plat = dev_get_platdata(bus); > struct kwspi_registers *reg = plat->spireg; > + const struct mvebu_spi_dev *drvdata; > u32 data = readl(®->cfg); > > data &= ~(KWSPI_CPHA | KWSPI_CPOL | KWSPI_RXLSBF | KWSPI_TXLSBF); > @@ -286,6 +316,10 @@ static int mvebu_spi_set_mode(struct udevice *bus, uint > mode) > > writel(data, ®->cfg); > > + drvdata = (struct mvebu_spi_dev *)dev_get_driver_data(bus); > + if (drvdata->is_errata_50mhz_ac) > + mvebu_spi_50mhz_ac_timing_erratum(bus, mode); > + > return 0; > } > > @@ -343,10 +377,32 @@ static const struct dm_spi_ops mvebu_spi_ops = { > */ > }; > > +static const struct mvebu_spi_dev armada_xp_spi_dev_data = { > + .typ = ARMADA_SPI, > +}; > + > +static const struct mvebu_spi_dev armada_375_spi_dev_data = { > + .typ = ARMADA_SPI, > +}; > + > +static const struct mvebu_spi_dev armada_380_spi_dev_data = { > + .typ = ARMADA_SPI, > + .is_errata_50mhz_ac = true, > +}; > + > static const struct udevice_id mvebu_spi_ids[] = { > - { .compatible = "marvell,armada-375-spi" }, > - { .compatible = "marvell,armada-380-spi" }, > - { .compatible = "marvell,armada-xp-spi" }, > + { > + .compatible = "marvell,armada-375-spi", > + .data = (ulong)&armada_375_spi_dev_data > + }, > + { > + .compatible = "marvell,armada-380-spi", > + .data = (ulong)&armada_380_spi_dev_data > + }, > + { > + .compatible = "marvell,armada-xp-spi", > + .data = (ulong)&armada_xp_spi_dev_data > + }, > { } > }; > > -- > 2.14.2 > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
