All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ben Chuang <benchuanggli@gmail.com>
To: adrian.hunter@intel.com, ulf.hansson@linaro.org
Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
	johnsonm@danlj.org, ben.chuang@genesyslogic.com.tw,
	Ben Chuang <benchuanggli@gmail.com>
Subject: [PATCH V5 2/4] mmc: sdhci: Add PLL Enable support to internal clock setup
Date: Tue, 20 Aug 2019 10:06:36 +0800	[thread overview]
Message-ID: <20190820020636.8279-1-benchuanggli@gmail.com> (raw)

From: Ben Chuang <ben.chuang@genesyslogic.com.tw>

The GL9750 and GL9755 chipsets, and possibly others, require PLL Enable
setup as part of the internal clock setup as described in 3.2.1 Internal
Clock Setup Sequence of SD Host Controller Simplified Specification
Version 4.20.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Co-developed-by: Michael K Johnson <johnsonm@danlj.org>
Signed-off-by: Michael K Johnson <johnsonm@danlj.org>
---
 drivers/mmc/host/sdhci.c | 23 +++++++++++++++++++++++
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 24 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index bed0760a6c2a..9106ebc7a422 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1653,6 +1653,29 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
 		udelay(10);
 	}
 
+	if (host->version >= SDHCI_SPEC_410 && host->v4_mode) {
+		clk |= SDHCI_CLOCK_PLL_EN;
+		clk &= ~SDHCI_CLOCK_INT_STABLE;
+		sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+		/* Wait max 150 ms */
+		timeout = ktime_add_ms(ktime_get(), 150);
+		while (1) {
+			bool timedout = ktime_after(ktime_get(), timeout);
+
+			clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+			if (clk & SDHCI_CLOCK_INT_STABLE)
+				break;
+			if (timedout) {
+				pr_err("%s: PLL clock never stabilised.\n",
+				       mmc_hostname(host->mmc));
+				sdhci_dumpregs(host);
+				return;
+			}
+			udelay(10);
+		}
+	}
+
 	clk |= SDHCI_CLOCK_CARD_EN;
 	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 }
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 199712e7adbb..72601a4d2e95 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -114,6 +114,7 @@
 #define  SDHCI_DIV_HI_MASK	0x300
 #define  SDHCI_PROG_CLOCK_MODE	0x0020
 #define  SDHCI_CLOCK_CARD_EN	0x0004
+#define  SDHCI_CLOCK_PLL_EN	0x0008
 #define  SDHCI_CLOCK_INT_STABLE	0x0002
 #define  SDHCI_CLOCK_INT_EN	0x0001
 
-- 
2.22.1


             reply	other threads:[~2019-08-20  2:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-20  2:06 Ben Chuang [this message]
2019-08-21 12:04 ` [PATCH V5 2/4] mmc: sdhci: Add PLL Enable support to internal clock setup Adrian Hunter

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=20190820020636.8279-1-benchuanggli@gmail.com \
    --to=benchuanggli@gmail.com \
    --cc=adrian.hunter@intel.com \
    --cc=ben.chuang@genesyslogic.com.tw \
    --cc=johnsonm@danlj.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mmc@vger.kernel.org \
    --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
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.