Re: [U-Boot] [PATCH 06/20] tegra: spi: Drop the claim_bus() method to correct delays

On 02/17/2015 03:29 PM, Simon Glass wrote:

At present the driver does not properly honour the requested SPI CS deactivation delay since the SPI bus is changed in the claim_bus() method.

Everything the claim_bus() method does can be done when the device is probed (setting the speed and mode) and at the start of a new transfer (where the fifo_status is already cleared). So drop this method.

Also, until the delay is complete, we should not touch the bus, so make sure that spi_cs_activate() is called before other things are done in the xfer() method.

diff --git a/drivers/spi/tegra114_spi.c b/drivers/spi/tegra114_spi.c

• setbits_le32(&regs->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW |

•      (priv->mode << SPI_CMD1_MODE_SHIFT));
  

...

• setbits_le32(&priv->regs->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW |

•      (priv->mode << SPI_CMD1_MODE_SHIFT) | SPI_CMD1_CS_SW_VAL);
  

Is that addition of SPI_CMD1_CS_SW_VAL there relative to the old code intended?