From e974ccfaa262642cccc758e8cf1f7415b711d408 Mon Sep 17 00:00:00 2001
From: jmcneill <jmcneill@NetBSD.org>
Date: Sun, 3 May 2015 11:46:25 +0000
Subject: [PATCH] Add SDHC_FLAG_SINGLE_POWER_WRITE flag, that tells the driver
 to update the SDHC_POWER_CTL register with a single write rather than in
 multiple steps. Required for Tegra K1 SDHC.

---
 sys/dev/sdmmc/sdhc.c    | 25 ++++++++++++++++---------
 sys/dev/sdmmc/sdhcvar.h |  3 ++-
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/sys/dev/sdmmc/sdhc.c b/sys/dev/sdmmc/sdhc.c
index 1544ae355399..efa8201e45b6 100644
--- a/sys/dev/sdmmc/sdhc.c
+++ b/sys/dev/sdmmc/sdhc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: sdhc.c,v 1.56 2015/05/02 12:10:24 jmcneill Exp $	*/
+/*	$NetBSD: sdhc.c,v 1.57 2015/05/03 11:46:25 jmcneill Exp $	*/
 /*	$OpenBSD: sdhc.c,v 1.25 2009/01/13 19:44:20 grange Exp $	*/
 
 /*
@@ -23,7 +23,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sdhc.c,v 1.56 2015/05/02 12:10:24 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sdhc.c,v 1.57 2015/05/03 11:46:25 jmcneill Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_sdmmc.h"
@@ -755,13 +755,20 @@ sdhc_bus_power(sdmmc_chipset_handle_t sch, uint32_t ocr)
 		 * Enable bus power.  Wait at least 1 ms (or 74 clocks) plus
 		 * voltage ramp until power rises.
 		 */
-		HWRITE1(hp, SDHC_POWER_CTL,
-		    HREAD1(hp, SDHC_POWER_CTL) & pcmask);
-		sdmmc_delay(1);
-		HWRITE1(hp, SDHC_POWER_CTL, (vdd << SDHC_VOLTAGE_SHIFT));
-		sdmmc_delay(1);
-		HSET1(hp, SDHC_POWER_CTL, SDHC_BUS_POWER);
-		sdmmc_delay(10000);
+
+		if (ISSET(hp->sc->sc_flags, SDHC_FLAG_SINGLE_POWER_WRITE)) {
+			HWRITE1(hp, SDHC_POWER_CTL,
+			    (vdd << SDHC_VOLTAGE_SHIFT) | SDHC_BUS_POWER);
+		} else {
+			HWRITE1(hp, SDHC_POWER_CTL,
+			    HREAD1(hp, SDHC_POWER_CTL) & pcmask);
+			sdmmc_delay(1);
+			HWRITE1(hp, SDHC_POWER_CTL,
+			    (vdd << SDHC_VOLTAGE_SHIFT));
+			sdmmc_delay(1);
+			HSET1(hp, SDHC_POWER_CTL, SDHC_BUS_POWER);
+			sdmmc_delay(10000);
+		}
 
 		/*
 		 * The host system may not power the bus due to battery low,
diff --git a/sys/dev/sdmmc/sdhcvar.h b/sys/dev/sdmmc/sdhcvar.h
index 6dfbdb98d10f..32a0e984e406 100644
--- a/sys/dev/sdmmc/sdhcvar.h
+++ b/sys/dev/sdmmc/sdhcvar.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: sdhcvar.h,v 1.17 2015/05/02 12:10:24 jmcneill Exp $	*/
+/*	$NetBSD: sdhcvar.h,v 1.18 2015/05/03 11:46:25 jmcneill Exp $	*/
 /*	$OpenBSD: sdhcvar.h,v 1.3 2007/09/06 08:01:01 jsg Exp $	*/
 
 /*
@@ -53,6 +53,7 @@ struct sdhc_softc {
 #define	SDHC_FLAG_EXTERNAL_DMA	0x00004000
 #define	SDHC_FLAG_EXTDMA_DMAEN	0x00008000 /* ext. dma need SDHC_DMA_ENABLE */
 #define	SDHC_FLAG_NO_CLKBASE	0x00020000 /* ignore clkbase register */
+#define	SDHC_FLAG_SINGLE_POWER_WRITE 0x00040000
 
 	uint32_t		sc_clkbase;
 	int			sc_clkmsk;	/* Mask for SDCLK */