From: Andreas Fenkart <afenkart@xxxxxxxxx>
Date: Thu, 17 Jan 2019 15:39:52 +0100
Subject: [PATCH] mmc: meson-gx: enable signal re-sampling together with tuning
card detection fails on some p212 derived boards if enabled too early
mmc1: error -110 whilst initialising MMC card
Signed-off-by: Andreas Fenkart <afenkart@xxxxxxxxx>
---
drivers/mmc/host/meson-gx-mmc.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index c2690c1a50ff..b65ec4bea980 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -709,7 +709,8 @@ static int meson_mmc_find_tuning_point(unsigned long *test)
static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
struct clk *clk)
{
- int point, ret;
+ struct meson_host *host = mmc_priv(mmc);
+ int point, ret, adj = 0;
DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
@@ -729,6 +730,10 @@ static int meson_mmc_clk_phase_tuning(struct
mmc_host *mmc, u32 opcode,
if (point < 0)
return point; /* tuning failed */
+ /* enable signal resampling w/o delay */
+ adj = ADJUST_ADJ_EN;
+ writel(adj, host->regs + host->data->adjust);
+
clk_set_phase(clk, point * CLK_PHASE_STEP);
dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
clk_get_phase(clk));
@@ -768,6 +773,9 @@ static void meson_mmc_set_ios(struct mmc_host
*mmc, struct mmc_ios *ios)
if (!IS_ERR(mmc->supply.vmmc))
mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
+ /* disable signal resampling w/o delay */
+ writel(0, host->regs + host->data->adjust);
+
/* Reset rx phase */
clk_set_phase(host->rx_clk, 0);
@@ -1166,7 +1174,7 @@ static int meson_mmc_get_cd(struct mmc_host *mmc)
static void meson_mmc_cfg_init(struct meson_host *host)
{
- u32 cfg = 0, adj = 0;
+ u32 cfg = 0;
cfg |= FIELD_PREP(CFG_RESP_TIMEOUT_MASK,
ilog2(SD_EMMC_CFG_RESP_TIMEOUT));
@@ -1177,10 +1185,6 @@ static void meson_mmc_cfg_init(struct meson_host *host)
cfg |= CFG_ERR_ABORT;
writel(cfg, host->regs + SD_EMMC_CFG);
-
- /* enable signal resampling w/o delay */
- adj = ADJUST_ADJ_EN;
- writel(adj, host->regs + host->data->adjust);
}
static int meson_mmc_card_busy(struct mmc_host *mmc)
--
2.20.1
Am Do., 17. Jan. 2019 um 15:11 Uhr schrieb Jerome Brunet <jbrunet@xxxxxxxxxxxx>:
>
> On Thu, 2019-01-17 at 14:56 +0100, Andreas Fenkart wrote:
> > Am Do., 17. Jan. 2019 um 13:35 Uhr schrieb Andreas Fenkart <
> > afenkart@xxxxxxxxx>:
> > > Hi Jerome
> > > > Here your eMMC timedout during init, so even before an attempt is made
> > > > to tune
> > > > which is odd. Could you try to enable signal resampling only when going
> > > > forhigh speed modes ?
> >
> > card is found with this patch:
> >
> > --- a/drivers/mmc/host/meson-gx-mmc.c
> > +++ b/drivers/mmc/host/meson-gx-mmc.c
> > @@ -432,12 +432,17 @@ static int meson_mmc_clk_set(struct meson_host
> > *host, struct mmc_ios *ios)
> > struct mmc_host *mmc = host->mmc;
> > unsigned long rate = ios->clock;
> > int ret;
> > - u32 cfg;
> > + u32 cfg = 0, adj = 0;
> >
> > /* DDR modes require higher module clock */
> > if (meson_mmc_timing_is_ddr(ios))
> > rate <<= 1;
> >
> > /* Same request - bail-out */
> > if (host->req_rate == rate)
> > return 0;
> > @@ -475,6 +480,13 @@ static int meson_mmc_clk_set(struct meson_host
> > *host, struct mmc_ios *ios)
> > if (ios->clock != mmc->actual_clock)
> > dev_dbg(host->dev, "requested rate was %u\n", ios->clock);
> >
> > + if (rate >= 200000000) {
> > + printk("enable signal resampling");
> > + /* enable signal resampling w/o delay */
> > + adj = ADJUST_ADJ_EN;
> > + writel(adj, host->regs + host->data->adjust);
> > + }
> > +
>
> 200Mhz is a bit arbitrary.
> I would prefer if you enabled resampling when starting a tuning
> And disable it on power up, in the set_ios() callaback.
>
> > /* (re)start clock */
> > meson_mmc_clk_ungate(host);
> >
> > /Andi
>
>
