[U-Boot] [PATCH V2] spi: mxs: Configure chipselect after block reset

Marek Vasut marex at denx.de
Tue Aug 27 11:21:49 CEST 2013


Dear Jagan Teki,

> Hi,
> 
> On Tue, Aug 27, 2013 at 2:35 PM, Marek Vasut <marex at denx.de> wrote:
> > Dear Stefano Babic,
> > 
> >> On 26/08/2013 17:45, Marek Vasut wrote:
> >> > The chipselect must be written into the CTRL0 register after the SSP
> >> > block is reset, otherwise the block will always use ChipSelect #0.
> >> > 
> >> > Signed-off-by: Marek Vasut <marex at denx.de>
> >> > Cc: Fabio Estevam <fabio.estevam at freescale.com>
> >> > Cc: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
> >> > Cc: Otavio Salvador <otavio at ossystems.com.br>
> >> > Cc: Stefano Babic <sbabic at denx.de>
> >> > ---
> >> > 
> >> >  drivers/spi/mxs_spi.c |   12 +++---------
> >> >  1 file changed, 3 insertions(+), 9 deletions(-)
> >> > 
> >> > V2: Clean up a warning that "ssp_regs" are not used
> >> > 
> >> > diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
> >> > index 3cf7142..2b9f395 100644
> >> > --- a/drivers/spi/mxs_spi.c
> >> > +++ b/drivers/spi/mxs_spi.c
> >> > @@ -56,8 +56,6 @@ struct spi_slave *spi_setup_slave(unsigned int bus,
> >> > unsigned int cs,
> >> > 
> >> >                               unsigned int max_hz, unsigned int mode)
> >> >  
> >> >  {
> >> >  
> >> >     struct mxs_spi_slave *mxs_slave;
> >> > 
> >> > -   struct mxs_ssp_regs *ssp_regs;
> >> > -   int reg;
> >> > 
> >> >     if (!spi_cs_is_valid(bus, cs)) {
> >> >     
> >> >             printf("mxs_spi: invalid bus %d / chip select %d\n", bus,
> >> >             cs);
> >> > 
> >> > @@ -74,13 +72,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus,
> >> > unsigned int cs,
> >> > 
> >> >     mxs_slave->max_khz = max_hz / 1000;
> >> >     mxs_slave->mode = mode;
> >> >     mxs_slave->regs = mxs_ssp_regs_by_bus(bus);
> >> > 
> >> > -   ssp_regs = mxs_slave->regs;
> >> > 
> >> > -   reg = readl(&ssp_regs->hw_ssp_ctrl0);
> >> > -   reg &= ~(MXS_SSP_CHIPSELECT_MASK);
> >> > -   reg |= cs << MXS_SSP_CHIPSELECT_SHIFT;
> >> > -
> >> > -   writel(reg, &ssp_regs->hw_ssp_ctrl0);
> >> > 
> >> >     return &mxs_slave->slave;
> >> >  
> >> >  err_init:
> >> > @@ -102,7 +94,9 @@ int spi_claim_bus(struct spi_slave *slave)
> >> > 
> >> >     mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
> >> > 
> >> > -   writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
> >> > +   writel((slave->cs << MXS_SSP_CHIPSELECT_SHIFT) |
> >> > +          SSP_CTRL0_BUS_WIDTH_ONE_BIT,
> >> > +          &ssp_regs->hw_ssp_ctrl0);
> >> > 
> >> >     reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
> >> >     reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
> >> 
> >> Acked-by: Stefano Babic <sbabic at denx.de>
> > 
> > Can we push this via IMX tree ?
> 
> I have a simple concern about commit head msg.
> spi: mxs:
> spi: mxs_spi:
> 
> I preferred the second one as rest are follow the same, just for
> unification. Please send the v2, if your OK. then I will push it on my
> tree.

Can you fix that before pushing? I am fine either way.

Best regards,
Marek Vasut


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