On 12/07/2018 02:13 PM, Mason Yang wrote:
> Add a driver for Renesas R-Car Gen3 RPC SPI controller.
>
> Signed-off-by: Mason Yang <masonccyang@xxxxxxxxxxx>
> ---
> drivers/spi/Kconfig | 6 +
> drivers/spi/Makefile | 1 +
> drivers/spi/spi-renesas-rpc.c | 776 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 783 insertions(+)
> create mode 100644 drivers/spi/spi-renesas-rpc.c
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 7d3a5c9..54b40f8 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
[...]
> diff --git a/drivers/spi/spi-renesas-rpc.c b/drivers/spi/spi-renesas-rpc.c
> new file mode 100644
> index 0000000..cec5669
> --- /dev/null
> +++ b/drivers/spi/spi-renesas-rpc.c
> @@ -0,0 +1,776 @@
[...]
> +static int rpc_spi_do_reset(struct rpc_spi *rpc)
> +{
> + int ret;
> +
> + ret = reset_control_reset(rpc->rstc);
> + if (ret)
> + return ret;
> +
> + return 0;
This degrades to:
{
return reset_control_reset(rpc->rstc);
}
So, we hardly need this function now...
[...]
> +static int rpc_spi_io_xfer(struct rpc_spi *rpc,
> + const void *tx_buf, void *rx_buf)
> +{
> + u32 smenr, smcr, data, pos = 0;
> + int ret = 0;
> +
> + regmap_write(rpc->regmap, RPC_CMNCR, RPC_CMNCR_MD | RPC_CMNCR_SFDE |
> + RPC_CMNCR_MOIIO_HIZ | RPC_CMNCR_IOFV_HIZ |
> + RPC_CMNCR_BSZ(0));
> + regmap_write(rpc->regmap, RPC_SMDRENR, 0x0);
> + regmap_write(rpc->regmap, RPC_SMCMR, rpc->cmd);
> + regmap_write(rpc->regmap, RPC_SMDMCR, rpc->dummy);
> + regmap_write(rpc->regmap, RPC_SMADR, rpc->addr);
> +
> + if (tx_buf) {
> + smenr = rpc->smenr;
> +
> + while (pos < rpc->xferlen) {
> + u32 nbytes = rpc->xferlen - pos;
> +
> + regmap_write(rpc->regmap, RPC_SMWDR0,
> + get_unaligned((u32 *)(tx_buf + pos)));
> +
> + if (nbytes > 4) {
> + nbytes = 4;
> + smcr = rpc->smcr |
> + RPC_SMCR_SPIE | RPC_SMCR_SSLKP;
> + } else {
> + smcr = rpc->smcr | RPC_SMCR_SPIE;
> + }
> +
> + regmap_write(rpc->regmap, RPC_SMENR, smenr);
> + regmap_write(rpc->regmap, RPC_SMCR, smcr);
> + ret = wait_msg_xfer_end(rpc);
> + if (ret)
> + goto out;
> +
> + pos += nbytes;
> + smenr = rpc->smenr & ~RPC_SMENR_CDE &
> + ~RPC_SMENR_ADE(0xf);
> + }
> + } else if (rx_buf) {
> + while (pos < rpc->xferlen) {
> + u32 nbytes = rpc->xferlen - pos;
> +
> + if (nbytes > 4)
> + nbytes = 4;
> +
> + regmap_write(rpc->regmap, RPC_SMENR, rpc->smenr);
> + regmap_write(rpc->regmap, RPC_SMCR,
> + rpc->smcr | RPC_SMCR_SPIE);
Hm... our flash chip (Spansion S25FS512S) doesn't get detected; it sends
JEDEC ID bytes 0..3 repeatedly, unless I copy the SSLKP logic from the writing
branch above...
> + ret = wait_msg_xfer_end(rpc);
> + if (ret)
> + goto out;
> +
> + regmap_read(rpc->regmap, RPC_SMRDR0, &data);
> + memcpy_fromio(rx_buf + pos, (void *)&data, nbytes);
> + pos += nbytes;
... and it skips byte 4 unless I copy the code from the end of the writing
branch, clearing CDE/ADE. But even then the byte 4 reads as 0x03 instead of 0.
> + regmap_write(rpc->regmap, RPC_SMCMR, rpc->cmd);
> + regmap_write(rpc->regmap, RPC_SMDMCR, rpc->dummy);
> + regmap_write(rpc->regmap, RPC_SMADR, rpc->addr + pos);
> + }
> + } else {
> + regmap_write(rpc->regmap, RPC_SMENR, rpc->smenr);
> + regmap_write(rpc->regmap, RPC_SMCR, rpc->smcr | RPC_SMCR_SPIE);
> + ret = wait_msg_xfer_end(rpc);
> + if (ret)
> + goto out;
> + }
> +
> + return ret;
> +out:
> + return rpc_spi_do_reset(rpc);
> +}
[...]
MBR, Sergei
