Re: [PATCH 4/6] mmc: mediatek: tune CMD/DATA together

Matthias Brugger
2018-10-19T08:46:38Z

On 13/10/2018 09:20, Chaotian Jing wrote:
> for MSDC IP which supports both data tune and async fifo, it can
> tune cmd/data together. which can save the time and make the tune
> result of CMD more stable as data line are 4bit or 8bit.
>
> Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
> ---
> drivers/mmc/host/mtk-sd.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 87 insertions(+)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index fe80a1d..09d7e44 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -1773,12 +1773,98 @@ static int msdc_tune_data(struct mmc_host *mmc, u32 opcode)
> return final_delay == 0xff ? -EIO : 0;
> }
>
> +/*
> + * MSDC IP which supports data tune + async fifo can do CMD/DAT tune
> + * together, which can save the tuning time.
> + */
> +static int msdc_tune_together(struct mmc_host *mmc, u32 opcode)
> +{
> + struct msdc_host *host = mmc_priv(mmc);
> + u32 rise_delay = 0, fall_delay = 0;
> + struct msdc_delay_phase final_rise_delay, final_fall_delay = { 0,};
> + u8 final_delay, final_maxlen;
> + u32 tune_reg = host->dev_comp->pad_tune_reg;
> + int i, ret;
> +
> + sdr_set_field(host->base + MSDC_PATCH_BIT, MSDC_INT_DAT_LATCH_CK_SEL,
> + host->latch_ck);
> +
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + sdr_clr_bits(host->base + MSDC_IOCON,
> + MSDC_IOCON_DSPL | MSDC_IOCON_W_DSPL);
> + for (i = 0 ; i < PAD_DELAY_MAX; i++) {
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_CMDRDLY, i);
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_DATRRDLY, i);
> + ret = mmc_send_tuning(mmc, opcode, NULL);
> + if (!ret)
> + rise_delay |= (1 << i);
> + }
> + final_rise_delay = get_best_delay(host, rise_delay);
> + /* if rising edge has enough margin, then do not scan falling edge */
> + if (final_rise_delay.maxlen >= 12 ||
> + (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4))
> + goto skip_fall;
> +
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + sdr_set_bits(host->base + MSDC_IOCON,
> + MSDC_IOCON_DSPL | MSDC_IOCON_W_DSPL);
> + for (i = 0; i < PAD_DELAY_MAX; i++) {
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_CMDRDLY, i);
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_DATRRDLY, i);
> + ret = mmc_send_tuning(mmc, opcode, NULL);
> + if (!ret)
> + fall_delay |= (1 << i);
> + }
> + final_fall_delay = get_best_delay(host, fall_delay);
> +
> +skip_fall:
> + final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen);
> + if (final_maxlen == final_rise_delay.maxlen) {
> + sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + sdr_clr_bits(host->base + MSDC_IOCON,
> + MSDC_IOCON_DSPL | MSDC_IOCON_W_DSPL);
> + sdr_set_field(host->base + tune_reg, MSDC_PAD_TUNE_CMDRDLY,
> + final_rise_delay.final_phase);
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_DATRRDLY,
> + final_rise_delay.final_phase);
> + final_delay = final_rise_delay.final_phase;
> + } else {
> + sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL);
> + sdr_set_bits(host->base + MSDC_IOCON,
> + MSDC_IOCON_DSPL | MSDC_IOCON_W_DSPL);
> + sdr_set_field(host->base + tune_reg, MSDC_PAD_TUNE_CMDRDLY,
> + final_fall_delay.final_phase);
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_DATRRDLY,
> + final_fall_delay.final_phase);
> + final_delay = final_fall_delay.final_phase;
> + }
> +
> + dev_dbg(host->dev, "Final pad delay: %x\n", final_delay);
> + return final_delay == 0xff ? -EIO : 0;
> +}
> +
> static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> {
> struct msdc_host *host = mmc_priv(mmc);
> int ret;
> u32 tune_reg = host->dev_comp->pad_tune_reg;
>
> + if (host->dev_comp->data_tune && host->dev_comp->async_fifo) {
> + ret = msdc_tune_together(mmc, opcode);
> + if (host->hs400_mode) {
> + sdr_clr_bits(host->base + MSDC_IOCON,
> + MSDC_IOCON_DSPL | MSDC_IOCON_W_DSPL);
> + sdr_set_field(host->base + tune_reg,
> + MSDC_PAD_TUNE_DATRRDLY, 0);
> + }
> + goto tune_done;
> + }
> if (host->hs400_mode &&

Couldn't we put a else if here instead of using a goto?

Regards,
Matthias

> host->dev_comp->hs400_tune)
> ret = hs400_tune_response(mmc, opcode);
> @@ -1794,6 +1880,7 @@ static int msdc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> dev_err(host->dev, "Tune data fail!\n");
> }
>
> +tune_done:
> host->saved_tune_para.iocon = readl(host->base + MSDC_IOCON);
> host->saved_tune_para.pad_tune = readl(host->base + tune_reg);
> host->saved_tune_para.pad_cmd_tune = readl(host->base + PAD_CMD_TUNE);
>