Commit Graph

3 Commits

Author SHA1 Message Date
Mingkai Hu 0dd2c96f19 spi/fsl_espi: fix wrong setting of the address in the command buffer
Or else we can't operate on the right address when the trans length
is greater than 65535.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-24 01:53:57 -07:00
Mingkai Hu e6289d63a6 spi/fsl_espi: change the read behaviour of the SPIRF
The user must read N bytes of SPIRF (1 <= N <= 4) that do not exceed the
amount of data in the receive FIFO, so read the SPIRF byte by byte when
the data in receive FIFO is less than 4 bytes.

On Simics, when read N bytes that exceed the amount of data in receive
FIFO, we can't read the data out, that is we can't clear the rx FIFO,
then the CPU will loop on the espi rx interrupt.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-24 01:53:41 -07:00
Mingkai Hu 8b60d6c25b spi/fsl_spi: add eSPI controller support
Add eSPI controller support based on the library code spi_fsl_lib.c.

The eSPI controller is newer controller 85xx/Pxxx devices supported.
There're some differences comparing to the SPI controller:

1. Has different register map and different bit definition
   So leave the code operated the register to the driver code, not
   the common code.

2. Support 4 dedicated chip selects
   The software can't controll the chip selects directly, The SPCOM[CS]
   field is used to select which chip selects is used, and the
   SPCOM[TRANLEN] field is set to tell the controller how long the CS
   signal need to be asserted. So the driver doesn't need the chipselect
   related function when transfering data, just set corresponding register
   fields to controll the chipseclect.

3. Different Transmit/Receive FIFO access register behavior
   For SPI controller, the Tx/Rx FIFO access register can hold only
   one character regardless of the character length, but for eSPI
   controller, the register can hold 4 or 2 characters according to
   the character lengths. Access the Tx/Rx FIFO access register of the
   eSPI controller will shift out/in 4/2 characters one time. For SPI
   subsystem, the command and data are put into different transfers, so
   we need to combine all the transfers to one transfer in order to pass
   the transfer to eSPI controller.

4. The max transaction length limitation
   The max transaction length one time is limitted by the SPCOM[TRANSLEN]
   field which is 0xFFFF. When used mkfs.ext2 command to create ext2
   filesystem on the flash, the read length will exceed the max value of
   the SPCOM[TRANSLEN] field.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:38:12 -06:00