| Message ID | 1295201837-26836-2-git-send-email-agust@denx.de |
|---|---|
| State | Changes Requested |
| Delegated to: | Stefano Babic |
| Headers | show |
On 01/16/2011 07:17 PM, Anatolij Gustschin wrote: > The MXC SPI driver didn't calculate the SPI clock up to > now and just used lowest possible divider 512 for DATA > RATE in the control register. This results in very low > transfer rates. > Hi August, I sent last friday a patch for mxc_spi.c, too, adding support for mx35, and the two patches now conflict. Is it ok for you if I rebase your patch on top of mine and I post it again ? Best Regards, Stefano
Hello Stefano, On Mon, 17 Jan 2011 10:00:51 +0100 Stefano Babic <sbabic@denx.de> wrote: > On 01/16/2011 07:17 PM, Anatolij Gustschin wrote: > > The MXC SPI driver didn't calculate the SPI clock up to > > now and just used lowest possible divider 512 for DATA > > RATE in the control register. This results in very low > > transfer rates. > > > > Hi August, > > I sent last friday a patch for mxc_spi.c, too, adding support for mx35, > and the two patches now conflict. Is it ok for you if I rebase your > patch on top of mine and I post it again ? Yes, it is ok. Thanks, Anatolij -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office@denx.de
On Mon, 17 Jan 2011 10:30:09 +0100 Anatolij Gustschin <agust@denx.de> wrote: > Hello Stefano, > > On Mon, 17 Jan 2011 10:00:51 +0100 > Stefano Babic <sbabic@denx.de> wrote: > > > On 01/16/2011 07:17 PM, Anatolij Gustschin wrote: > > > The MXC SPI driver didn't calculate the SPI clock up to > > > now and just used lowest possible divider 512 for DATA > > > RATE in the control register. This results in very low > > > transfer rates. > > > > > > > Hi August, > > > > I sent last friday a patch for mxc_spi.c, too, adding support for mx35, > > and the two patches now conflict. Is it ok for you if I rebase your > > patch on top of mine and I post it again ? > > Yes, it is ok. BTW: While at it, could you then also please fix a mistake in the commit description: it should be "... just highest possible divider 512". Thanks, Anatolij -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: office@denx.de
On 01/17/2011 10:36 AM, Anatolij Gustschin wrote: > BTW: While at it, could you then also please fix a mistake in the > commit description: it should be "... just highest possible divider > 512". Of course, I will do it. Stefano
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c index 9ed2891..07c62c2 100644 --- a/drivers/spi/mxc_spi.c +++ b/drivers/spi/mxc_spi.c @@ -438,12 +438,25 @@ static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs) return cs; } +u32 get_cspi_div(u32 div) +{ + int i; + + for (i = 0; i < 8; i++) { + if (div <= (4 << i)) + return i; + } + return i; +} + struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, unsigned int max_hz, unsigned int mode) { unsigned int ctrl_reg; struct mxc_spi_slave *mxcs; int ret; + u32 clk_src; + u32 div; if (bus >= ARRAY_SIZE(spi_bases)) return NULL; @@ -477,9 +490,16 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, return NULL; } #else + clk_src = mx31_get_ipg_clk(); + div = clk_src / max_hz; + div = get_cspi_div(div); + + debug("clk %d Hz, div %d, real clk %d Hz\n", + max_hz, div, clk_src / (4 << div)); + ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) | MXC_CSPICTRL_BITCOUNT(31) | - MXC_CSPICTRL_DATARATE(7) | /* FIXME: calculate data rate */ + MXC_CSPICTRL_DATARATE(div) | MXC_CSPICTRL_EN | MXC_CSPICTRL_MODE;
The MXC SPI driver didn't calculate the SPI clock up to now and just used lowest possible divider 512 for DATA RATE in the control register. This results in very low transfer rates. The patch adds code to calculate and setup the SPI clock frequency for transfers. Signed-off-by: Anatolij Gustschin <agust@denx.de> --- drivers/spi/mxc_spi.c | 22 +++++++++++++++++++++- 1 files changed, 21 insertions(+), 1 deletions(-)