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

Chaotian Jing
2018-10-13T07:20:48Z

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 &&
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);
--
1.8.1.1.dirty