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

[York Sun <yorksun@freescale.com>]

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.

York


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@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);
>  }
>