Starterware/AM3359: SPI Driver issue - SPIEN set to low after Master Mode enabled

Thank you for your answer, Lali.

As an example code, I've used
C:\ti\pdk_am335x_1_0_5\packages\ti\drv\spi\test\mcspi_serial_flash\src\main_mcspi_dma_serial_flash_read_write.c

but without enabling dma. I've inspected Board_init() and all the underlying functions, so I do enable clock and pinmux for mcspi pins.
The code that does that in my case is an adaptaion of

C:\ti\pdk_am335x_1_0_5\packages\ti\board\src\evmAM335x\evmAM335x.c
C:\ti\pdk_am335x_1_0_5\packages\ti\starterware\soc\am335x\am335x_prcm.c
C:\ti\pdk_am335x_1_0_5\packages\ti\board\src\evmAM335x\evmAM335x_pinmux.c

in part of MCSPI module enabling and pinmuxing. In my case it looks as follows.

// EnableMcSpiClock is adaptation of enableModule(uint32_t domainOffset, uint32_t clkCtrlReg, .. )
// for CHIPDB_MOD_ID_MCSPI

template<typename HwDesc>
void EnableMcSpiClock()
{
    HwRegBlock<HwDesc::PrcmRegs> cmRegs;

    cmRegs[HwDesc::ClkCtrlReg].Field(CM_PER_SPI0_CLKCTRL_MODULEMODE).WriteThrough(CM_PER_SPI0_CLKCTRL_MODULEMODE_ENABLE);

// Field(bit).WriteThrough just writes specific bit (and only that bit)
// into the register and waits till it is set to the right value
// and HwRegBlock<base> cmRegs; cmRegs[reg] - is simply an access
// to target register, which is base + reg

    cmRegs[HwDesc::ClkStReg].Field(HwDesc::ClkActivityBit).WaitUntilSet();

    cmRegs[HwDesc::ClkCtrlReg].Field(CM_PER_SPI0_CLKCTRL_IDLEST).WaitUntilEquals(CM_PER_SPI0_CLKCTRL_IDLEST_FUNC << CM_PER_SPI0_CLKCTRL_IDLEST_SHIFT);
}

struct McSpi0HwDesc
{
    static constexpr int ModuleIndex = 0;
    static constexpr uint32_t Regs = SOC_SPI_0_REGS;
    static constexpr uint32_t Int = SOC_INT_SPI0INT;

    static constexpr uint32_t PrcmRegs = SOC_CM_PER_REGS;
    static constexpr uint32_t ClkCtrlReg = CM_PER_SPI0_CLKCTRL;
    static constexpr uint32_t ClkStReg = CM_PER_L3_CLKSTCTRL;
    static constexpr uint32_t ClkActivityBit = CM_PER_L3_CLKSTCTRL_CLKACTIVITY_L3_GCLK;
};

template class McSpi<McSpi0HwDesc>;

...

Then PinMuxing. The code for SPI pins is

...
SetMux(CONTROL_CONF_SPI0_SCLK,    Fast | IEn | PU | Mode0);
SetMux(CONTROL_CONF_SPI0_D0,         Fast | IEn | PU | Mode0);
SetMux(CONTROL_CONF_SPI0_D1,         Fast | IEn | PU | Mode0);
SetMux(CONTROL_CONF_SPI0_CS0,      Fast | IEn | PU | Mode0);
...

void SetMux(uint32_t pin, uint32_t val)
{
     HwRegBlock<SOC_CONTROL_REGS>()[pin] = val;
}

// Fast = 0,
// IEn = CONTROL_CONF_RXACTIVE
// PU = CONTROL_CONF_PULLUPSEL
// Mode0 = CONTROL_CONF_MUXMODE(0)

Hope that helps to clarify things a bit..

Thank you!

I've checked the registers, they seem to look fine, don't they?

conf_spi0_sclk 0x00000030   

conf_spi0_d0 0x00000030

conf_spi0_d1 0x00000030

conf_spi0_cs0 0x00000030

conf_spi0_cs1 0x00000030

0x00000030 is fast (0), rxactive(1), pulltypesel - pullup(1), pullup/pulldown enabled (0), muxmode (0)

Thank you, David.

I've changed pinmux to this

conf_spi0_sclk 0x00000030
conf_spi0_d0 0x00000030
conf_spi0_d1 0x00000030
conf_spi0_cs0 0x00000010
conf_spi0_cs1 0x00000010

0x00000030 is fast (0), rxactive(0), pulltypesel - pullup(1), pullup/pulldown enabled (0), muxmode (0)

but, unfortunately, the rest stays the same.

CS0 goes low right after SPI_Open (McSPIMasterModeEnable)

Hi Ilia,

I apologize I should have noticed this earlier.

The MCSPI_SerialFlash example (  http://processors.wiki.ti.com/index.php/Processor_SDK_RTOS_QSPI-McSPI ) is developed for the AM335 General Purpose EVM http://www.ti.com/tool/tmdxevm3358 . This EVM uses only SPI0_CLK and SPI0_D0  for communication to and the SPIFlash which is a W25Q64 that is on the daughercard. The Pinmux setting for each of these signals are 0x20.  These signals are not directly connected to the Flash. Instead they pass though a CPLD which provides inputs for SPI_Clk, SPI_DI, SPI_DO, and SPI_CS on the flash. The pin mux setting for SPI0_D1 and SPI0_CS0 are to configure them for I2C operation.

There is a starterware SPI flash read/write utility for the AM335 ICE V2  EVM http://www.ti.com/tool/tmdsice3359 . . 

This EVM has following direct connections to the AM3359.  The Pinmux settings for this are

conf_spi0_sclk  0x00000028 
conf_spi0_d0   0x00000028 
conf_spi0_d1   0x00000000 
conf_spi0_cs0  0x00000000 

The application is starterware mcspi_app_flash. When Building it is necessary to also have the starterware board, dal, device, example_utils, soc, and utils in the environment.

I have no problem building this application under the Industrial SDK http://www.ti.com/tool/sysbiossdk-ind-sitara with CCS 6.2.1 and GNU v4.8.4 .

I will need to do some investigation on how to build this under pdk_am335x_1_0_5

David

.

Hi David,

I've used the code as an example only.

I have a custom board, though with a very simple SPI flash assembly:

So, as soon as I disable MasterMode on mcspi, cs0 goes back UP.

I thought maybe something is wrong with the specific chip I use, but I see the same thing on another (AM3354) chip that I've just checked.