Linux-mmc Archive on lore.kernel.org
 help / color / Atom feed
From: Faiz Abbas <faiz_abbas@ti.com>
To: <linux-omap@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-mmc@vger.kernel.org>
Cc: <adrian.hunter@intel.com>, <kishon@ti.com>,
	<mark.rutland@arm.com>, <robh+dt@kernel.org>,
	<ulf.hansson@linaro.org>, <faiz_abbas@ti.com>, <tony@atomide.com>
Subject: [PATCH v5 10/10] mmc: sdhci-omap: Add special reset capability
Date: Thu, 16 Jan 2020 16:21:54 +0530
Message-ID: <20200116105154.7685-11-faiz_abbas@ti.com> (raw)
In-Reply-To: <20200116105154.7685-1-faiz_abbas@ti.com>

Some omap controllers need software to monitor a 0->1->0 for software
reset. Add a SDHCI_OMAP_SPECIAL_RESET flag to indicate this.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-omap.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 5433c9e6ac10..882053151a47 100644
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -86,6 +86,7 @@
 
 /* sdhci-omap controller flags */
 #define SDHCI_OMAP_REQUIRE_IODELAY	BIT(0)
+#define SDHCI_OMAP_SPECIAL_RESET	BIT(1)
 
 struct sdhci_omap_data {
 	u32 offset;
@@ -779,15 +780,35 @@ static void sdhci_omap_set_uhs_signaling(struct sdhci_host *host,
 	sdhci_omap_start_clock(omap_host);
 }
 
+#define MMC_TIMEOUT_US		20000		/* 20000 micro Sec */
 static void sdhci_omap_reset(struct sdhci_host *host, u8 mask)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+	unsigned long limit = MMC_TIMEOUT_US;
+	unsigned long i = 0;
 
 	/* Don't reset data lines during tuning operation */
 	if (omap_host->is_tuning)
 		mask &= ~SDHCI_RESET_DATA;
 
+	if (omap_host->flags & SDHCI_OMAP_SPECIAL_RESET) {
+		sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
+		while ((!(sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)) &&
+		       (i++ < limit))
+			udelay(1);
+		i = 0;
+		while ((sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) &&
+		       (i++ < limit))
+			udelay(1);
+
+		if (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)
+			dev_err(mmc_dev(host->mmc),
+				"Timeout waiting on controller reset in %s\n",
+				__func__);
+		return;
+	}
+
 	sdhci_reset(host, mask);
 }
 
@@ -900,10 +921,12 @@ static const struct sdhci_omap_data k2g_data = {
 
 static const struct sdhci_omap_data am335_data = {
 	.offset = 0x200,
+	.flags = SDHCI_OMAP_SPECIAL_RESET,
 };
 
 static const struct sdhci_omap_data am437_data = {
 	.offset = 0x200,
+	.flags = SDHCI_OMAP_SPECIAL_RESET,
 };
 
 static const struct sdhci_omap_data dra7_data = {
-- 
2.19.2


  parent reply index

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-16 10:51 [PATCH v5 00/10] Port am335x and am437x devices to sdhci-omap Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 01/10] dt-bindings: sdhci-omap: Add properties for using external dma Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 02/10] mmc: sdhci: Factor out some operations set to their own functions Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 03/10] mmc: sdhci: add support for using external DMA devices Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 04/10] mmc: sdhci-omap: Add using external dma Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 05/10] mmc: sdhci: Convert sdhci_set_timeout_irq() to non-static Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 06/10] mmc: sdhci: Refactor sdhci_set_timeout() Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 07/10] mmc: sdhci-omap: Disable data timeout interrupt during erase Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 08/10] dt-bindings: sdhci-omap: Add am335x and am437x specific bindings Faiz Abbas
2020-01-16 10:51 ` [PATCH v5 09/10] mmc: sdhci-omap: Add am335x and am437x specific compatibles Faiz Abbas
2020-01-16 10:51 ` Faiz Abbas [this message]
2020-01-16 15:37 ` [PATCH v5 00/10] Port am335x and am437x devices to sdhci-omap Ulf Hansson

Reply instructions:

You may reply publically 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=20200116105154.7685-11-faiz_abbas@ti.com \
    --to=faiz_abbas@ti.com \
    --cc=adrian.hunter@intel.com \
    --cc=devicetree@vger.kernel.org \
    --cc=kishon@ti.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mmc@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=robh+dt@kernel.org \
    --cc=tony@atomide.com \
    --cc=ulf.hansson@linaro.org \
    /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

Linux-mmc Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mmc/0 linux-mmc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mmc linux-mmc/ https://lore.kernel.org/linux-mmc \
		linux-mmc@vger.kernel.org
	public-inbox-index linux-mmc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-mmc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git