diff mbox series

[V6,2/5] mmc: sdhci: Add PLL Enable support to internal clock setup

Message ID 20190827003255.2347-1-benchuanggli@gmail.com (mailing list archive)
State New, archived
Headers show
Series Add Genesys Logic GL975x support | expand

Commit Message

Ben Chuang Aug. 27, 2019, 12:32 a.m. UTC 
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>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci.c | 23 +++++++++++++++++++++++
 drivers/mmc/host/sdhci.h |  1 +
 2 files changed, 24 insertions(+)
diff mbox series

Patch

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