From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-mmc@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
Takeshi Saito <takeshi.saito.xv@renesas.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [RFC PATCH v2 2/5] mmc: renesas_sdhi: Add manual correction
Date: Tue, 17 Dec 2019 12:40:31 +0100 [thread overview]
Message-ID: <20191217114034.13290-3-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20191217114034.13290-1-wsa+renesas@sang-engineering.com>
From: Takeshi Saito <takeshi.saito.xv@renesas.com>
This patch adds a manual correction mechanism for SDHI. Currently, SDHI
uses automatic TAP position correction. However, TAP position can also
be corrected manually via correction error status flags.
Signed-off-by: Takeshi Saito <takeshi.saito.xv@renesas.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
drivers/mmc/host/renesas_sdhi.h | 1 +
drivers/mmc/host/renesas_sdhi_core.c | 61 +++++++++++++++++++++++-----
2 files changed, 52 insertions(+), 10 deletions(-)
diff --git a/drivers/mmc/host/renesas_sdhi.h b/drivers/mmc/host/renesas_sdhi.h
index f524251d5113..11a0b2bca3aa 100644
--- a/drivers/mmc/host/renesas_sdhi.h
+++ b/drivers/mmc/host/renesas_sdhi.h
@@ -57,6 +57,7 @@ struct renesas_sdhi {
void __iomem *scc_ctl;
u32 scc_tappos;
u32 scc_tappos_hs400;
+ bool doing_tune;
};
#define host_to_priv(host) \
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 519d91ae3373..6cedc0a10593 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -263,6 +263,8 @@ static int renesas_sdhi_start_signal_voltage_switch(struct mmc_host *mmc,
#define SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN BIT(0)
/* Definitions for values the SH_MOBILE_SDHI_SCC_RVSREQ register */
#define SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR BIT(2)
+#define SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPUP BIT(1)
+#define SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPDOWN BIT(0)
/* Definitions for values the SH_MOBILE_SDHI_SCC_TMPPORT2 register */
#define SH_MOBILE_SDHI_SCC_TMPPORT2_HS400OSEL BIT(4)
#define SH_MOBILE_SDHI_SCC_TMPPORT2_HS400EN BIT(31)
@@ -321,6 +323,8 @@ static void renesas_sdhi_prepare_tuning(struct tmio_mmc_host *host,
{
struct renesas_sdhi *priv = host_to_priv(host);
+ priv->doing_tune = true;
+
/* Set sampling clock position */
sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, tap);
}
@@ -426,6 +430,8 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host)
unsigned long ntap; /* temporary counter of tuning success */
unsigned long i;
+ priv->doing_tune = false;
+
/* Clear SCC_RVSREQ */
sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
@@ -485,6 +491,47 @@ static int renesas_sdhi_select_tuning(struct tmio_mmc_host *host)
return 0;
}
+static bool renesas_sdhi_manual_correction(struct tmio_mmc_host *host, bool use_4tap)
+{
+ struct renesas_sdhi *priv = host_to_priv(host);
+ u32 val;
+
+ val = sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ);
+ if (!val)
+ return false;
+
+ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
+
+ /* Change TAP position according to correction status */
+ if (val & SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR)
+ return true; /* Need re-tune */
+ else if (val & SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPUP)
+ host->tap_set = (host->tap_set + 1) % host->tap_num;
+ else if (val & SH_MOBILE_SDHI_SCC_RVSREQ_REQTAPDOWN)
+ host->tap_set = (host->tap_set - 1) % host->tap_num;
+ else
+ return false;
+
+ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET,
+ host->tap_set / (use_4tap ? 2 : 1));
+
+ return false;
+}
+
+static bool renesas_sdhi_auto_correction(struct tmio_mmc_host *host)
+{
+ struct renesas_sdhi *priv = host_to_priv(host);
+
+ /* Check SCC error */
+ if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ) &
+ SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) {
+ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
+ return true;
+ }
+
+ return false;
+}
+
static bool renesas_sdhi_check_scc_error(struct tmio_mmc_host *host)
{
struct renesas_sdhi *priv = host_to_priv(host);
@@ -499,20 +546,14 @@ static bool renesas_sdhi_check_scc_error(struct tmio_mmc_host *host)
!(host->mmc->ios.timing == MMC_TIMING_MMC_HS400 && !use_4tap))
return false;
- if (mmc_doing_retune(host->mmc))
+ if (mmc_doing_retune(host->mmc) || priv->doing_tune)
return false;
- /* Check SCC error */
if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL) &
- SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN &&
- sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ) &
- SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) {
- /* Clear SCC error */
- sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0);
- return true;
- }
+ SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN)
+ return renesas_sdhi_auto_correction(host);
- return false;
+ return renesas_sdhi_manual_correction(host, use_4tap);
}
static void renesas_sdhi_hw_reset(struct tmio_mmc_host *host)
--
2.20.1
next prev parent reply other threads:[~2019-12-17 11:40 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-17 11:40 [RFC PATCH v2 0/5] mmc: renesas_sdhi: add manual correction Wolfram Sang
2019-12-17 11:40 ` [RFC PATCH v2 1/5] mmc: renesas_sdhi: remove double clear of automatic correction Wolfram Sang
2019-12-17 11:40 ` Wolfram Sang [this message]
2019-12-17 11:40 ` [RFC PATCH v2 3/5] mmc: renesas_sdhi: only check CMD status for HS400 manual correction Wolfram Sang
2020-01-30 10:04 ` Yoshihiro Shimoda
2019-12-17 11:40 ` [RFC PATCH v2 4/5] mmc: renesas_sdhi: enforce manual correction for Gen3 Wolfram Sang
2019-12-17 11:40 ` [RFC PATCH v2 5/5] mmc: renesas_sdhi: cleanup SCC defines Wolfram Sang
2020-01-30 10:05 ` Yoshihiro Shimoda
2020-02-13 13:55 ` [RFC PATCH v2 0/5] mmc: renesas_sdhi: add manual correction Ulf Hansson
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