[U-Boot] u-boot, fsl_espi.c driver

[Jagan Teki]

On 9 October 2014 21:55, York Sun <yorksun at freescale.com> wrote:
> Dear Joakim,
>
> Thanks for raising a concern.
>
> It's not fair to blame the last person who submitted a patch. We are all working
> to make it better as an opensource comminuty. You have done a good job to hack
> it to work. Would it be nicer if you can submit this or improved patch to u-boot
> community for further review and testing, after putting informing commit
> message? The mailing list address is CC'ed.

Could you please elaborate the issue?

> On 10/09/2014 09:14 AM, Joakim Tjernlund wrote:
>> Guys, I noticed you have added to the fsl eSPI driver and you work for
>> Freescale.
>> This driver is broken beyond words, just look what I had to hack to load a
>> FPGA over SPI(below).
>> I hope you can take the time to fix the driver.
>>
>> From e73b8bd36b42e39ee9e22b48deca3a54fbffe4ac Mon Sep 17 00:00:00 2001
>> From: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
>> Date: Mon, 3 Mar 2014 16:30:35 +0100
>> Subject: [PATCH] Fast fixes to make eSPI driver work.
>>
>> The whole driver stinks, needs to be rewritten.
>> ---
>>  drivers/spi/fsl_espi.c | 19 +++++++++++--------
>>  1 file changed, 11 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/spi/fsl_espi.c b/drivers/spi/fsl_espi.c
>> index ae0fe58..f5a8fcc 100644
>> --- a/drivers/spi/fsl_espi.c
>> +++ b/drivers/spi/fsl_espi.c
>> @@ -45,6 +45,8 @@ struct fsl_spi_slave {
>>
>>  #define ESPI_COM_CS(x)         ((x) << 30)
>>  #define ESPI_COM_TRANLEN(x)    ((x) << 0)
>> +#define ESPI_COM_TO             (1 << (31 - 4))
>> +
>>
>>  #define ESPI_CSMODE_CI_INACTIVEHIGH    (1 << 31)
>>  #define ESPI_CSMODE_CP_BEGIN_EDGCLK    (1 << 30)
>> @@ -165,8 +167,9 @@ int spi_claim_bus(struct spi_slave *slave)
>>                         | ESPI_CSMODE_CI_INACTIVEHIGH);
>>         /* Character bit order: msb first */
>> -       out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
>> -               | ESPI_CSMODE_REV_MSB_FIRST);
>> +       if (!(mode & SPI_LSB_FIRST))
>> +               out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
>> +                        | ESPI_CSMODE_REV_MSB_FIRST);
>>
>>         /* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
>>         out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
>> @@ -302,14 +305,15 @@ int spi_xfer(struct spi_slave *slave, unsigned int
>> bitlen, const void *data_out,
>>               *(uint *)data_out, data_out, *(uint *)data_in, data_in,
>> len);
>>
>>         num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
>> +       dout = buffer;
>>         while (num_chunks--) {
>>                 if (data_in)
>>                         din = buffer + rx_offset;
>> -               dout = buffer;
>>                 tran_len = min(data_len , max_tran_len);
>>                 num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
>>                 num_bytes = (tran_len + cmd_len) % 4;
>>                 fsl->data_len = tran_len + cmd_len;
>> +               data_len -= tran_len;
>>                 spi_cs_activate(slave);
>>
>>                 /* Clear all eSPI events */
>> @@ -320,12 +324,11 @@ int spi_xfer(struct spi_slave *slave, unsigned int
>> bitlen, const void *data_out,
>>                         if (event & ESPI_EV_TNF) {
>>                                 fsl_espi_tx(fsl, dout);
>>                                 /* Set up the next iteration */
>> -                               if (len > 4) {
>> -                                       len -= 4;
>> -                                       dout += 4;
>> -                               }
>> +                               len -= 4;
>> +                               dout += 4;
>>                         }
>>
>> +                       num_blks--;
>>                         event = in_be32(&espi->event);
>>                         if (event & ESPI_EV_RNE) {
>>                                 rf_cnt = ((event & ESPI_EV_RFCNT_MASK)
>> @@ -338,7 +341,6 @@ int spi_xfer(struct spi_slave *slave, unsigned int
>> bitlen, const void *data_out,
>>                                         continue;
>>                                 if (fsl_espi_rx(fsl, din, rx_bytes)
>>                                                 == rx_bytes) {
>> -                                       num_blks--;
>>                                         if (din)
>>                                                 din = (unsigned char *)din
>>                                                         + rx_bytes;
>> @@ -374,6 +376,7 @@ void spi_cs_activate(struct spi_slave *slave)
>>
>>         com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
>>         com |= ESPI_COM_CS(slave->cs);
>> +       com |= ESPI_COM_TO;
>>         com |= ESPI_COM_TRANLEN(data_len - 1);
>>         out_be32(&espi->com, com);
>>  }
>>

thanks!
-- 
Jagan.