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>,
Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [RFC PATCH 2/2] mmc: renesas_sdhi: enfore manual correction for Gen3
Date: Tue, 3 Dec 2019 21:33:00 +0100 [thread overview]
Message-ID: <20191203203301.2202-3-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20191203203301.2202-1-wsa+renesas@sang-engineering.com>
HW engineers say that automatic tap correction cannot be used for HS400
in all R-Car Gen3 SoCs. So, check for that SDHI variant and disable it
when HS400 is about to be enabled.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
The BSP handles this differently and adds a quirk entry to every
soc_device_match and checks the quirk entry. I chose this less intrusive
method because all Gen3 SoCs are affected. But not all SDHI instances,
only those which can access eMMC, of course. So, I likes this approach a
tad better. If you think all quirks should be centralized in the quirks
structure, I am open for discussion.
drivers/mmc/host/renesas_sdhi_core.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 903da3ba399b..a29290ee2051 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -343,6 +343,12 @@ static void renesas_sdhi_hs400_complete(struct tmio_mmc_host *host)
sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DT2FF,
priv->scc_tappos_hs400);
+ /* Gen3 can't do automatic tap correction with HS400, so disable it */
+ if (sd_ctrl_read16(host, CTL_VERSION) == SDHI_VER_GEN3_SDMMC)
+ sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL,
+ ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN &
+ sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL));
+
sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TMPPORT2,
(SH_MOBILE_SDHI_SCC_TMPPORT2_HS400EN |
SH_MOBILE_SDHI_SCC_TMPPORT2_HS400OSEL) |
--
2.20.1
next prev parent reply other threads:[~2019-12-03 20:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-03 20:32 [RFC PATCH 0/2] mmc: renesas_sdhi: add manual correction Wolfram Sang
2019-12-03 20:32 ` [RFC PATCH 1/2] mmc: renesas_sdhi: Add " Wolfram Sang
2019-12-04 9:44 ` Geert Uytterhoeven
2019-12-10 22:28 ` Wolfram Sang
2019-12-11 7:43 ` Geert Uytterhoeven
2019-12-13 16:18 ` Wolfram Sang
2019-12-09 6:42 ` Yoshihiro Shimoda
2019-12-03 20:33 ` Wolfram Sang [this message]
2019-12-04 9:39 ` [RFC PATCH 2/2] mmc: renesas_sdhi: enfore manual correction for Gen3 Geert Uytterhoeven
2019-12-09 7:00 ` Yoshihiro Shimoda
2019-12-03 20:33 ` [RFC PATCH 3/2] mmc: renesas_sdhi: remove double clear of automatic correction Wolfram Sang
2019-12-09 7:01 ` Yoshihiro Shimoda
2019-12-10 22:32 ` [RFC PATCH 0/2] mmc: renesas_sdhi: add manual correction Wolfram Sang
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