All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marcel Ziswiler <marcel@ziswiler.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v4 2/3] mmc: tegra: allow disabling external clock loopback
Date: Tue, 21 Mar 2017 10:29:57 +0100	[thread overview]
Message-ID: <20170321092958.4440-3-marcel@ziswiler.com> (raw)
In-Reply-To: <20170321092958.4440-1-marcel@ziswiler.com>

From: Marcel Ziswiler <marcel.ziswiler@toradex.com>

Introduce CONFIG_TEGRA124_MMC_DISABLE_EXT_LOOPBACK to disable the external clock
loopback and use the internal one on SDMMC3 as per the SDMMC_VENDOR_MISC_CNTRL_0
register's SDMMC_SPARE1 bits being set to 0xfffd according to the TRM.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
---

Changes in v4:
- Re-based.

Changes in v3: None
Changes in v2:
- Added Simon's reviewed-by.
- Added TODO(email) as suggested by Simon so it is clear this is
  temporary and will be moved to device tree controlled approach once
  proper kernel integration made it mainline.

 arch/arm/include/asm/arch-tegra/tegra_mmc.h |  2 ++
 drivers/mmc/Kconfig                         | 11 +++++++++++
 drivers/mmc/tegra_mmc.c                     | 16 ++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/arch/arm/include/asm/arch-tegra/tegra_mmc.h b/arch/arm/include/asm/arch-tegra/tegra_mmc.h
index 64c848a..c40599a 100644
--- a/arch/arm/include/asm/arch-tegra/tegra_mmc.h
+++ b/arch/arm/include/asm/arch-tegra/tegra_mmc.h
@@ -108,6 +108,8 @@ struct tegra_mmc {
 #define TEGRA_MMC_CLKCON_SDCLK_FREQ_SEL_SHIFT			8
 #define TEGRA_MMC_CLKCON_SDCLK_FREQ_SEL_MASK			(0xff << 8)
 
+#define TEGRA_MMC_MISCON_ENABLE_EXT_LOOPBACK			(1 << 17)
+
 #define TEGRA_MMC_SWRST_SW_RESET_FOR_ALL			(1 << 0)
 #define TEGRA_MMC_SWRST_SW_RESET_FOR_CMD_LINE			(1 << 1)
 #define TEGRA_MMC_SWRST_SW_RESET_FOR_DAT_LINE			(1 << 2)
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index ddef59a..3a6dcec 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -345,6 +345,17 @@ config MMC_SUNXI
 
 endif
 
+config TEGRA124_MMC_DISABLE_EXT_LOOPBACK
+	bool "Disable external clock loopback"
+	depends on MMC_SDHCI_TEGRA && TEGRA124
+	help
+	  Disable the external clock loopback and use the internal one on SDMMC3
+	  as per the SDMMC_VENDOR_MISC_CNTRL_0 register's SDMMC_SPARE1 bits
+	  being set to 0xfffd according to the TRM.
+
+	  TODO(marcel.ziswiler at toradex.com): Move to device tree controlled
+	  approach once proper kernel integration made it mainline.
+
 endmenu
 
 config SYS_FSL_ERRATUM_ESDHC111
diff --git a/drivers/mmc/tegra_mmc.c b/drivers/mmc/tegra_mmc.c
index 0df74ef..6c6affb 100644
--- a/drivers/mmc/tegra_mmc.c
+++ b/drivers/mmc/tegra_mmc.c
@@ -513,6 +513,22 @@ static int tegra_mmc_init(struct mmc *mmc)
 
 	tegra_mmc_reset(priv, mmc);
 
+#if defined(CONFIG_TEGRA124_MMC_DISABLE_EXT_LOOPBACK)
+	/*
+	 * Disable the external clock loopback and use the internal one on
+	 * SDMMC3 as per the SDMMC_VENDOR_MISC_CNTRL_0 register's SDMMC_SPARE1
+	 * bits being set to 0xfffd according to the TRM.
+	 *
+	 * TODO(marcel.ziswiler@toradex.com): Move to device tree controlled
+	 * approach once proper kernel integration made it mainline.
+	 */
+	if (priv->reg == (void *)0x700b0400) {
+		mask = readl(&priv->reg->venmiscctl);
+		mask &= ~TEGRA_MMC_MISCON_ENABLE_EXT_LOOPBACK;
+		writel(mask, &priv->reg->venmiscctl);
+	}
+#endif
+
 	priv->version = readw(&priv->reg->hcver);
 	debug("host version = %x\n", priv->version);
 
-- 
2.9.3

  parent reply	other threads:[~2017-03-21  9:29 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-21  9:29 [U-Boot] [PATCH v4 0/3] arm: tegra: apalis-tk1 and ext clock loopback Marcel Ziswiler
2017-03-21  9:29 ` [U-Boot] [PATCH v4 1/3] arm: tegra: initial support for apalis tk1 Marcel Ziswiler
2017-03-21  9:29 ` Marcel Ziswiler [this message]
2017-03-21 22:19   ` [U-Boot] [PATCH v4 2/3] mmc: tegra: allow disabling external clock loopback Jaehoon Chung
2017-03-21  9:29 ` [U-Boot] [PATCH v4 3/3] apalis-tk1: disable external clock loopback on SDMMC3 Marcel Ziswiler
2017-03-21  9:46 ` [U-Boot] [PATCH v4 0/3] arm: tegra: apalis-tk1 and ext clock loopback Alexander Graf
2017-03-21 13:37   ` Marcel Ziswiler
2017-03-21 13:50     ` Alexander Graf
2017-03-24 22:22       ` Marcel Ziswiler
2017-03-24 22:40         ` Alexander Graf
2017-03-24 23:52           ` Marcel Ziswiler
2017-04-01  4:22             ` Simon Glass
2017-04-03  9:02               ` Alexander Graf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170321092958.4440-3-marcel@ziswiler.com \
    --to=marcel@ziswiler.com \
    --cc=u-boot@lists.denx.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.