[U-Boot] [PATCH 1/2][v2] powerpc: eSPI and eSPI controller support

[Mike Frysinger]

On Thu, Apr 21, 2011 at 2:04 AM, Shaohui Xie wrote:
> +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> +               unsigned int max_hz, unsigned int mode)
> +{
> +       ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);

you support just one bus ?  that's no fun ;).

> +       /* Enable eSPI interface */
> +       out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
> +                       | ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
> +
> +       out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
> +       out_be32(&espi->mask, 0x00000000); /* Mask  all eSPI interrupts */
> +
> +       /* Init CS mode interface */
> +       for (i = 0; i < ESPI_MAX_CS_NUM; i++)
> +               out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
> +
> +       out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
> +               ~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
> +               | ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
> +               | ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
> ........

usually spi_setup_slave() is to get the slave client ready to be used.
 it shouldnt be programming any actual hardware registers.  that is
the point of the spi_claim_bus() and spi_release_bus() steps ... use
the information in the slave state to setup the hardware for that
slave and then break it down in the release step.

> +static u8 cmd_buf[16];
> +static size_t cmd_len;
> +static size_t data_len;
> +
> +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
> +               void *data_in, unsigned long flags)
> +{
> +       ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
> +       unsigned int tmpdout, tmpdin, event;
> +       const void *dout = NULL;
> +       void *din = NULL;
> +       unsigned int len;
> +       int numBlks;
> +       int num_bytes;
> +       unsigned char *ch;
> +       unsigned char *buffer;
> +       size_t buf_len;
> +
> +       switch (flags) {
> +       case SPI_XFER_BEGIN:
> +               cmd_len = bitlen / 8;
> +               memcpy(cmd_buf, data_out, cmd_len);
> +               return 0;

interesting solution to the problem, but i'd think it might make more
sense to have this state live in the slave data rather than in the
global bus.

> +void spi_cs_activate(struct spi_slave *slave)
> +{
> +       ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
> +       unsigned int com = 0;
> +
> +       com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
> +       com |= ESPI_COM_CS(slave->cs);
> +       com |= ESPI_COM_TRANLEN(data_len - 1);
> +       out_be32(&espi->com, com);
> +
> +       return;
> +}

that return is useless and can be punted
-mike