[LEDE-DEV] [PATCH] brcm2708: backport upstream sdhost controller driver

Rafał Miłecki zajec5 at gmail.com
Sat Apr 1 06:30:10 PDT 2017


From: Rafał Miłecki <rafal at milecki.pl>

Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
 target/linux/brcm2708/bcm2708/config-4.9           |    1 +
 ...-Add-new-driver-for-the-sdhost-controller.patch | 1536 ++++++++++++++++++++
 ...-Fix-possible-NULL-ptr-dereference-in-bcm.patch |   30 +
 ...-rename-Kconfig-symbol-to-avoid-downstrea.patch |   40 +
 4 files changed, 1607 insertions(+)
 create mode 100644 target/linux/brcm2708/patches-4.9/080-0001-mmc-bcm2835-Add-new-driver-for-the-sdhost-controller.patch
 create mode 100644 target/linux/brcm2708/patches-4.9/080-0002-mmc-bcm2835-Fix-possible-NULL-ptr-dereference-in-bcm.patch
 create mode 100644 target/linux/brcm2708/patches-4.9/080-0100-mmc-bcm2835-rename-Kconfig-symbol-to-avoid-downstrea.patch

diff --git a/target/linux/brcm2708/bcm2708/config-4.9 b/target/linux/brcm2708/bcm2708/config-4.9
index c1bed074c3..76dd1fde18 100644
--- a/target/linux/brcm2708/bcm2708/config-4.9
+++ b/target/linux/brcm2708/bcm2708/config-4.9
@@ -251,6 +251,7 @@ CONFIG_MMC_BCM2835=y
 CONFIG_MMC_BCM2835_DMA=y
 CONFIG_MMC_BCM2835_PIO_DMA_BARRIER=2
 CONFIG_MMC_BCM2835_SDHOST=y
+# CONFIG_MMC_BCM2835_UPSTREAM is not set
 CONFIG_MMC_BLOCK=y
 CONFIG_MMC_BLOCK_MINORS=32
 CONFIG_MMC_SDHCI=y
diff --git a/target/linux/brcm2708/patches-4.9/080-0001-mmc-bcm2835-Add-new-driver-for-the-sdhost-controller.patch b/target/linux/brcm2708/patches-4.9/080-0001-mmc-bcm2835-Add-new-driver-for-the-sdhost-controller.patch
new file mode 100644
index 0000000000..2c0238cad9
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.9/080-0001-mmc-bcm2835-Add-new-driver-for-the-sdhost-controller.patch
@@ -0,0 +1,1536 @@
+From a7d3e315a02c3154c38d09e51fc9461ba2cac396 Mon Sep 17 00:00:00 2001
+From: Eric Anholt <eric at anholt.net>
+Date: Wed, 8 Mar 2017 10:19:03 +0100
+Subject: [PATCH] mmc: bcm2835: Add new driver for the sdhost controller.
+
+The 2835 has two SD controllers: The Arasan sdhci controller (supported
+by the iproc driver) and a custom sdhost controller.  This patch adds a
+driver for the latter.
+
+The sdhci controller supports both sdcard and sdio.  The sdhost
+controller supports the sdcard only, but has better performance.  Also
+note that the rpi3 has sdio wifi, so driving the sdcard with the sdhost
+controller allows to use the sdhci controller for wifi support.
+
+The configuration is done by devicetree via pin muxing.  Both SD
+controller are available on the same pins (2 pin groups = pin 22 to 27 +
+pin 48 to 53).  So it's possible to use both SD controllers at the same
+time with different pin groups.
+
+The code was originally written by Phil Elwell in the downstream
+Rasbperry Pi tree.   In preparation for the upstream merge it was
+cleaned up and the code base was moderized by Eric Anholt, Stefan
+Wahren and Gerd Hoffmann.
+
+Signed-off-by: Eric Anholt <eric at anholt.net>
+Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
+Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
+Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
+---
+ drivers/mmc/host/Kconfig   |   14 +
+ drivers/mmc/host/Makefile  |    1 +
+ drivers/mmc/host/bcm2835.c | 1465 ++++++++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 1480 insertions(+)
+ create mode 100644 drivers/mmc/host/bcm2835.c
+
+--- a/drivers/mmc/host/Kconfig
++++ b/drivers/mmc/host/Kconfig
+@@ -769,6 +769,20 @@ config MMC_TOSHIBA_PCI
+ 	depends on PCI
+ 	help
+ 
++config MMC_BCM2835
++	tristate "Broadcom BCM2835 SDHOST MMC Controller support"
++	depends on ARCH_BCM2835 || COMPILE_TEST
++	depends on HAS_DMA
++	help
++	  This selects the BCM2835 SDHOST MMC controller. If you have
++	  a BCM2835 platform with SD or MMC devices, say Y or M here.
++
++	  Note that the BCM2835 has two SD controllers: The Arasan
++	  sdhci controller (supported by MMC_SDHCI_IPROC) and a custom
++	  sdhost controller (supported by this driver).
++
++	  If unsure, say N.
++
+ config MMC_MTK
+ 	tristate "MediaTek SD/MMC Card Interface support"
+ 	depends on HAS_DMA
+--- a/drivers/mmc/host/Makefile
++++ b/drivers/mmc/host/Makefile
+@@ -57,6 +57,7 @@ obj-$(CONFIG_MMC_MOXART)	+= moxart-mmc.o
+ obj-$(CONFIG_MMC_SUNXI)		+= sunxi-mmc.o
+ obj-$(CONFIG_MMC_USDHI6ROL0)	+= usdhi6rol0.o
+ obj-$(CONFIG_MMC_TOSHIBA_PCI)	+= toshsd.o
++obj-$(CONFIG_MMC_BCM2835)	+= bcm2835.o
+ 
+ obj-$(CONFIG_MMC_REALTEK_PCI)	+= rtsx_pci_sdmmc.o
+ obj-$(CONFIG_MMC_REALTEK_USB)	+= rtsx_usb_sdmmc.o
+--- /dev/null
++++ b/drivers/mmc/host/bcm2835.c
+@@ -0,0 +1,1465 @@
++/*
++ * bcm2835 sdhost driver.
++ *
++ * The 2835 has two SD controllers: The Arasan sdhci controller
++ * (supported by the iproc driver) and a custom sdhost controller
++ * (supported by this driver).
++ *
++ * The sdhci controller supports both sdcard and sdio.  The sdhost
++ * controller supports the sdcard only, but has better performance.
++ * Also note that the rpi3 has sdio wifi, so driving the sdcard with
++ * the sdhost controller allows to use the sdhci controller for wifi
++ * support.
++ *
++ * The configuration is done by devicetree via pin muxing.  Both
++ * SD controller are available on the same pins (2 pin groups = pin 22
++ * to 27 + pin 48 to 53).  So it's possible to use both SD controllers
++ * at the same time with different pin groups.
++ *
++ * Author:      Phil Elwell <phil at raspberrypi.org>
++ *              Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
++ *
++ * Based on
++ *  mmc-bcm2835.c by Gellert Weisz
++ * which is, in turn, based on
++ *  sdhci-bcm2708.c by Broadcom
++ *  sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
++ *  sdhci.c and sdhci-pci.c by Pierre Ossman
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms and conditions of the GNU General Public License,
++ * version 2, as published by the Free Software Foundation.
++ *
++ * This program is distributed in the hope it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
++ */
++#include <linux/clk.h>
++#include <linux/delay.h>
++#include <linux/device.h>
++#include <linux/dmaengine.h>
++#include <linux/dma-mapping.h>
++#include <linux/err.h>
++#include <linux/highmem.h>
++#include <linux/interrupt.h>
++#include <linux/io.h>
++#include <linux/iopoll.h>
++#include <linux/module.h>
++#include <linux/of_address.h>
++#include <linux/of_irq.h>
++#include <linux/platform_device.h>
++#include <linux/scatterlist.h>
++#include <linux/time.h>
++#include <linux/workqueue.h>
++
++#include <linux/mmc/host.h>
++#include <linux/mmc/mmc.h>
++#include <linux/mmc/sd.h>
++
++#define SDCMD  0x00 /* Command to SD card              - 16 R/W */
++#define SDARG  0x04 /* Argument to SD card             - 32 R/W */
++#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
++#define SDCDIV 0x0c /* Start value for clock divider   - 11 R/W */
++#define SDRSP0 0x10 /* SD card response (31:0)         - 32 R   */
++#define SDRSP1 0x14 /* SD card response (63:32)        - 32 R   */
++#define SDRSP2 0x18 /* SD card response (95:64)        - 32 R   */
++#define SDRSP3 0x1c /* SD card response (127:96)       - 32 R   */
++#define SDHSTS 0x20 /* SD host status                  - 11 R/W */
++#define SDVDD  0x30 /* SD card power control           -  1 R/W */
++#define SDEDM  0x34 /* Emergency Debug Mode            - 13 R/W */
++#define SDHCFG 0x38 /* Host configuration              -  2 R/W */
++#define SDHBCT 0x3c /* Host byte count (debug)         - 32 R/W */
++#define SDDATA 0x40 /* Data to/from SD card            - 32 R/W */
++#define SDHBLC 0x50 /* Host block count (SDIO/SDHC)    -  9 R/W */
++
++#define SDCMD_NEW_FLAG			0x8000
++#define SDCMD_FAIL_FLAG			0x4000
++#define SDCMD_BUSYWAIT			0x800
++#define SDCMD_NO_RESPONSE		0x400
++#define SDCMD_LONG_RESPONSE		0x200
++#define SDCMD_WRITE_CMD			0x80
++#define SDCMD_READ_CMD			0x40
++#define SDCMD_CMD_MASK			0x3f
++
++#define SDCDIV_MAX_CDIV			0x7ff
++
++#define SDHSTS_BUSY_IRPT		0x400
++#define SDHSTS_BLOCK_IRPT		0x200
++#define SDHSTS_SDIO_IRPT		0x100
++#define SDHSTS_REW_TIME_OUT		0x80
++#define SDHSTS_CMD_TIME_OUT		0x40
++#define SDHSTS_CRC16_ERROR		0x20
++#define SDHSTS_CRC7_ERROR		0x10
++#define SDHSTS_FIFO_ERROR		0x08
++/* Reserved */
++/* Reserved */
++#define SDHSTS_DATA_FLAG		0x01
++
++#define SDHSTS_TRANSFER_ERROR_MASK	(SDHSTS_CRC7_ERROR | \
++					 SDHSTS_CRC16_ERROR | \
++					 SDHSTS_REW_TIME_OUT | \
++					 SDHSTS_FIFO_ERROR)
++
++#define SDHSTS_ERROR_MASK		(SDHSTS_CMD_TIME_OUT | \
++					 SDHSTS_TRANSFER_ERROR_MASK)
++
++#define SDHCFG_BUSY_IRPT_EN	BIT(10)
++#define SDHCFG_BLOCK_IRPT_EN	BIT(8)
++#define SDHCFG_SDIO_IRPT_EN	BIT(5)
++#define SDHCFG_DATA_IRPT_EN	BIT(4)
++#define SDHCFG_SLOW_CARD	BIT(3)
++#define SDHCFG_WIDE_EXT_BUS	BIT(2)
++#define SDHCFG_WIDE_INT_BUS	BIT(1)
++#define SDHCFG_REL_CMD_LINE	BIT(0)
++
++#define SDVDD_POWER_OFF		0
++#define SDVDD_POWER_ON		1
++
++#define SDEDM_FORCE_DATA_MODE	BIT(19)
++#define SDEDM_CLOCK_PULSE	BIT(20)
++#define SDEDM_BYPASS		BIT(21)
++
++#define SDEDM_WRITE_THRESHOLD_SHIFT	9
++#define SDEDM_READ_THRESHOLD_SHIFT	14
++#define SDEDM_THRESHOLD_MASK		0x1f
++
++#define SDEDM_FSM_MASK		0xf
++#define SDEDM_FSM_IDENTMODE	0x0
++#define SDEDM_FSM_DATAMODE	0x1
++#define SDEDM_FSM_READDATA	0x2
++#define SDEDM_FSM_WRITEDATA	0x3
++#define SDEDM_FSM_READWAIT	0x4
++#define SDEDM_FSM_READCRC	0x5
++#define SDEDM_FSM_WRITECRC	0x6
++#define SDEDM_FSM_WRITEWAIT1	0x7
++#define SDEDM_FSM_POWERDOWN	0x8
++#define SDEDM_FSM_POWERUP	0x9
++#define SDEDM_FSM_WRITESTART1	0xa
++#define SDEDM_FSM_WRITESTART2	0xb
++#define SDEDM_FSM_GENPULSES	0xc
++#define SDEDM_FSM_WRITEWAIT2	0xd
++#define SDEDM_FSM_STARTPOWDOWN	0xf
++
++#define SDDATA_FIFO_WORDS	16
++
++#define FIFO_READ_THRESHOLD	4
++#define FIFO_WRITE_THRESHOLD	4
++#define SDDATA_FIFO_PIO_BURST	8
++
++#define PIO_THRESHOLD	1  /* Maximum block count for PIO (0 = always DMA) */
++
++struct bcm2835_host {
++	spinlock_t		lock;
++	struct mutex		mutex;
++
++	void __iomem		*ioaddr;
++	u32			phys_addr;
++
++	struct mmc_host		*mmc;
++	struct platform_device	*pdev;
++
++	int			clock;		/* Current clock speed */
++	unsigned int		max_clk;	/* Max possible freq */
++	struct work_struct	dma_work;
++	struct delayed_work	timeout_work;	/* Timer for timeouts */
++	struct sg_mapping_iter	sg_miter;	/* SG state for PIO */
++	unsigned int		blocks;		/* remaining PIO blocks */
++	int			irq;		/* Device IRQ */
++
++	u32			ns_per_fifo_word;
++
++	/* cached registers */
++	u32			hcfg;
++	u32			cdiv;
++
++	struct mmc_request	*mrq;		/* Current request */
++	struct mmc_command	*cmd;		/* Current command */
++	struct mmc_data		*data;		/* Current data request */
++	bool			data_complete:1;/* Data finished before cmd */
++	bool			use_busy:1;	/* Wait for busy interrupt */
++	bool			use_sbc:1;	/* Send CMD23 */
++
++	/* for threaded irq handler */
++	bool			irq_block;
++	bool			irq_busy;
++	bool			irq_data;
++
++	/* DMA part */
++	struct dma_chan		*dma_chan_rxtx;
++	struct dma_chan		*dma_chan;
++	struct dma_slave_config dma_cfg_rx;
++	struct dma_slave_config dma_cfg_tx;
++	struct dma_async_tx_descriptor	*dma_desc;
++	u32			dma_dir;
++	u32			drain_words;
++	struct page		*drain_page;
++	u32			drain_offset;
++	bool			use_dma;
++};
++
++static void bcm2835_dumpcmd(struct bcm2835_host *host, struct mmc_command *cmd,
++			    const char *label)
++{
++	struct device *dev = &host->pdev->dev;
++
++	if (!cmd)
++		return;
++
++	dev_dbg(dev, "%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n",
++		(cmd == host->cmd) ? '>' : ' ',
++		label, cmd->opcode, cmd->arg, cmd->flags,
++		cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3],
++		cmd->error);
++}
++
++static void bcm2835_dumpregs(struct bcm2835_host *host)
++{
++	struct mmc_request *mrq = host->mrq;
++	struct device *dev = &host->pdev->dev;
++
++	if (mrq) {
++		bcm2835_dumpcmd(host, mrq->sbc, "sbc");
++		bcm2835_dumpcmd(host, mrq->cmd, "cmd");
++		if (mrq->data) {
++			dev_dbg(dev, "data blocks %x blksz %x - err %d\n",
++				mrq->data->blocks,
++				mrq->data->blksz,
++				mrq->data->error);
++		}
++		bcm2835_dumpcmd(host, mrq->stop, "stop");
++	}
++
++	dev_dbg(dev, "=========== REGISTER DUMP ===========\n");
++	dev_dbg(dev, "SDCMD  0x%08x\n", readl(host->ioaddr + SDCMD));
++	dev_dbg(dev, "SDARG  0x%08x\n", readl(host->ioaddr + SDARG));
++	dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT));
++	dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV));
++	dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0));
++	dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1));
++	dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2));
++	dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3));
++	dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS));
++	dev_dbg(dev, "SDVDD  0x%08x\n", readl(host->ioaddr + SDVDD));
++	dev_dbg(dev, "SDEDM  0x%08x\n", readl(host->ioaddr + SDEDM));
++	dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG));
++	dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT));
++	dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC));
++	dev_dbg(dev, "===========================================\n");
++}
++
++static void bcm2835_reset_internal(struct bcm2835_host *host)
++{
++	u32 temp;
++
++	writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
++	writel(0, host->ioaddr + SDCMD);
++	writel(0, host->ioaddr + SDARG);
++	writel(0xf00000, host->ioaddr + SDTOUT);
++	writel(0, host->ioaddr + SDCDIV);
++	writel(0x7f8, host->ioaddr + SDHSTS); /* Write 1s to clear */
++	writel(0, host->ioaddr + SDHCFG);
++	writel(0, host->ioaddr + SDHBCT);
++	writel(0, host->ioaddr + SDHBLC);
++
++	/* Limit fifo usage due to silicon bug */
++	temp = readl(host->ioaddr + SDEDM);
++	temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) |
++		  (SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT));
++	temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
++		(FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
++	writel(temp, host->ioaddr + SDEDM);
++	msleep(20);
++	writel(SDVDD_POWER_ON, host->ioaddr + SDVDD);
++	msleep(20);
++	host->clock = 0;
++	writel(host->hcfg, host->ioaddr + SDHCFG);
++	writel(host->cdiv, host->ioaddr + SDCDIV);
++}
++
++static void bcm2835_reset(struct mmc_host *mmc)
++{
++	struct bcm2835_host *host = mmc_priv(mmc);
++
++	if (host->dma_chan)
++		dmaengine_terminate_sync(host->dma_chan);
++	bcm2835_reset_internal(host);
++}
++
++static void bcm2835_finish_command(struct bcm2835_host *host);
++
++static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
++{
++	int timediff;
++	u32 alternate_idle;
++
++	alternate_idle = (host->mrq->data->flags & MMC_DATA_READ) ?
++		SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
++
++	timediff = 0;
++
++	while (1) {
++		u32 edm, fsm;
++
++		edm = readl(host->ioaddr + SDEDM);
++		fsm = edm & SDEDM_FSM_MASK;
++
++		if ((fsm == SDEDM_FSM_IDENTMODE) ||
++		    (fsm == SDEDM_FSM_DATAMODE))
++			break;
++		if (fsm == alternate_idle) {
++			writel(edm | SDEDM_FORCE_DATA_MODE,
++			       host->ioaddr + SDEDM);
++			break;
++		}
++
++		timediff++;
++		if (timediff == 100000) {
++			dev_err(&host->pdev->dev,
++				"wait_transfer_complete - still waiting after %d retries\n",
++				timediff);
++			bcm2835_dumpregs(host);
++			host->mrq->data->error = -ETIMEDOUT;
++			return;
++		}
++		cpu_relax();
++	}
++}
++
++static void bcm2835_dma_complete(void *param)
++{
++	struct bcm2835_host *host = param;
++
++	schedule_work(&host->dma_work);
++}
++
++static void bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read)
++{
++	unsigned long flags;
++	size_t blksize;
++	unsigned long wait_max;
++
++	blksize = host->data->blksz;
++
++	wait_max = jiffies + msecs_to_jiffies(500);
++
++	local_irq_save(flags);
++
++	while (blksize) {
++		int copy_words;
++		u32 hsts = 0;
++		size_t len;
++		u32 *buf;
++
++		if (!sg_miter_next(&host->sg_miter)) {
++			host->data->error = -EINVAL;
++			break;
++		}
++
++		len = min(host->sg_miter.length, blksize);
++		if (len % 4) {
++			host->data->error = -EINVAL;
++			break;
++		}
++
++		blksize -= len;
++		host->sg_miter.consumed = len;
++
++		buf = (u32 *)host->sg_miter.addr;
++
++		copy_words = len / 4;
++
++		while (copy_words) {
++			int burst_words, words;
++			u32 edm;
++
++			burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words);
++			edm = readl(host->ioaddr + SDEDM);
++			if (is_read)
++				words = ((edm >> 4) & 0x1f);
++			else
++				words = SDDATA_FIFO_WORDS - ((edm >> 4) & 0x1f);
++
++			if (words < burst_words) {
++				int fsm_state = (edm & SDEDM_FSM_MASK);
++				struct device *dev = &host->pdev->dev;
++
++				if ((is_read &&
++				     (fsm_state != SDEDM_FSM_READDATA &&
++				      fsm_state != SDEDM_FSM_READWAIT &&
++				      fsm_state != SDEDM_FSM_READCRC)) ||
++				    (!is_read &&
++				     (fsm_state != SDEDM_FSM_WRITEDATA &&
++				      fsm_state != SDEDM_FSM_WRITESTART1 &&
++				      fsm_state != SDEDM_FSM_WRITESTART2))) {
++					hsts = readl(host->ioaddr + SDHSTS);
++					dev_err(dev, "fsm %x, hsts %08x\n",
++						fsm_state, hsts);
++					if (hsts & SDHSTS_ERROR_MASK)
++						break;
++				}
++
++				if (time_after(jiffies, wait_max)) {
++					dev_err(dev, "PIO %s timeout - EDM %08x\n",
++						is_read ? "read" : "write",
++						edm);
++					hsts = SDHSTS_REW_TIME_OUT;
++					break;
++				}
++				ndelay((burst_words - words) *
++				       host->ns_per_fifo_word);
++				continue;
++			} else if (words > copy_words) {
++				words = copy_words;
++			}
++
++			copy_words -= words;
++
++			while (words) {
++				if (is_read)
++					*(buf++) = readl(host->ioaddr + SDDATA);
++				else
++					writel(*(buf++), host->ioaddr + SDDATA);
++				words--;
++			}
++		}
++
++		if (hsts & SDHSTS_ERROR_MASK)
++			break;
++	}
++
++	sg_miter_stop(&host->sg_miter);
++
++	local_irq_restore(flags);
++}
++
++static void bcm2835_transfer_pio(struct bcm2835_host *host)
++{
++	struct device *dev = &host->pdev->dev;
++	u32 sdhsts;
++	bool is_read;
++
++	is_read = (host->data->flags & MMC_DATA_READ) != 0;
++	bcm2835_transfer_block_pio(host, is_read);
++
++	sdhsts = readl(host->ioaddr + SDHSTS);
++	if (sdhsts & (SDHSTS_CRC16_ERROR |
++		      SDHSTS_CRC7_ERROR |
++		      SDHSTS_FIFO_ERROR)) {
++		dev_err(dev, "%s transfer error - HSTS %08x\n",
++			is_read ? "read" : "write", sdhsts);
++		host->data->error = -EILSEQ;
++	} else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
++			      SDHSTS_REW_TIME_OUT))) {
++		dev_err(dev, "%s timeout error - HSTS %08x\n",
++			is_read ? "read" : "write", sdhsts);
++		host->data->error = -ETIMEDOUT;
++	}
++}
++
++static
++void bcm2835_prepare_dma(struct bcm2835_host *host, struct mmc_data *data)
++{
++	int len, dir_data, dir_slave;
++	struct dma_async_tx_descriptor *desc = NULL;
++	struct dma_chan *dma_chan;
++
++	dma_chan = host->dma_chan_rxtx;
++	if (data->flags & MMC_DATA_READ) {
++		dir_data = DMA_FROM_DEVICE;
++		dir_slave = DMA_DEV_TO_MEM;
++	} else {
++		dir_data = DMA_TO_DEVICE;
++		dir_slave = DMA_MEM_TO_DEV;
++	}
++
++	/* The block doesn't manage the FIFO DREQs properly for
++	 * multi-block transfers, so don't attempt to DMA the final
++	 * few words.  Unfortunately this requires the final sg entry
++	 * to be trimmed.  N.B. This code demands that the overspill
++	 * is contained in a single sg entry.
++	 */
++
++	host->drain_words = 0;
++	if ((data->blocks > 1) && (dir_data == DMA_FROM_DEVICE)) {
++		struct scatterlist *sg;
++		u32 len;
++		int i;
++
++		len = min((u32)(FIFO_READ_THRESHOLD - 1) * 4,
++			  (u32)data->blocks * data->blksz);
++
++		for_each_sg(data->sg, sg, data->sg_len, i) {
++			if (sg_is_last(sg)) {
++				WARN_ON(sg->length < len);
++				sg->length -= len;
++				host->drain_page = sg_page(sg);
++				host->drain_offset = sg->offset + sg->length;
++			}
++		}
++		host->drain_words = len / 4;
++	}
++
++	/* The parameters have already been validated, so this will not fail */
++	(void)dmaengine_slave_config(dma_chan,
++				     (dir_data == DMA_FROM_DEVICE) ?
++				     &host->dma_cfg_rx :
++				     &host->dma_cfg_tx);
++
++	len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
++			 dir_data);
++
++	if (len > 0) {
++		desc = dmaengine_prep_slave_sg(dma_chan, data->sg,
++					       len, dir_slave,
++					       DMA_PREP_INTERRUPT |
++					       DMA_CTRL_ACK);
++	}
++
++	if (desc) {
++		desc->callback = bcm2835_dma_complete;
++		desc->callback_param = host;
++		host->dma_desc = desc;
++		host->dma_chan = dma_chan;
++		host->dma_dir = dir_data;
++	}
++}
++
++static void bcm2835_start_dma(struct bcm2835_host *host)
++{
++	dmaengine_submit(host->dma_desc);
++	dma_async_issue_pending(host->dma_chan);
++}
++
++static void bcm2835_set_transfer_irqs(struct bcm2835_host *host)
++{
++	u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
++		SDHCFG_BUSY_IRPT_EN;
++
++	if (host->dma_desc) {
++		host->hcfg = (host->hcfg & ~all_irqs) |
++			SDHCFG_BUSY_IRPT_EN;
++	} else {
++		host->hcfg = (host->hcfg & ~all_irqs) |
++			SDHCFG_DATA_IRPT_EN |
++			SDHCFG_BUSY_IRPT_EN;
++	}
++
++	writel(host->hcfg, host->ioaddr + SDHCFG);
++}
++
++static
++void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_command *cmd)
++{
++	struct mmc_data *data = cmd->data;
++
++	WARN_ON(host->data);
++
++	host->data = data;
++	if (!data)
++		return;
++
++	host->data_complete = false;
++	host->data->bytes_xfered = 0;
++
++	if (!host->dma_desc) {
++		/* Use PIO */
++		int flags = SG_MITER_ATOMIC;
++
++		if (data->flags & MMC_DATA_READ)
++			flags |= SG_MITER_TO_SG;
++		else
++			flags |= SG_MITER_FROM_SG;
++		sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
++		host->blocks = data->blocks;
++	}
++
++	bcm2835_set_transfer_irqs(host);
++
++	writel(data->blksz, host->ioaddr + SDHBCT);
++	writel(data->blocks, host->ioaddr + SDHBLC);
++}
++
++static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host, u32 max_ms)
++{
++	struct device *dev = &host->pdev->dev;
++	u32 value;
++	int ret;
++
++	ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
++				 !(value & SDCMD_NEW_FLAG), 1, 10);
++	if (ret == -ETIMEDOUT)
++		/* if it takes a while make poll interval bigger */
++		ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
++					 !(value & SDCMD_NEW_FLAG),
++					 10, max_ms * 1000);
++	if (ret == -ETIMEDOUT)
++		dev_err(dev, "%s: timeout (%d ms)\n", __func__, max_ms);
++
++	return value;
++}
++
++static void bcm2835_finish_request(struct bcm2835_host *host)
++{
++	struct dma_chan *terminate_chan = NULL;
++	struct mmc_request *mrq;
++
++	cancel_delayed_work(&host->timeout_work);
++
++	mrq = host->mrq;
++
++	host->mrq = NULL;
++	host->cmd = NULL;
++	host->data = NULL;
++
++	host->dma_desc = NULL;
++	terminate_chan = host->dma_chan;
++	host->dma_chan = NULL;
++
++	if (terminate_chan) {
++		int err = dmaengine_terminate_all(terminate_chan);
++
++		if (err)
++			dev_err(&host->pdev->dev,
++				"failed to terminate DMA (%d)\n", err);
++	}
++
++	mmc_request_done(host->mmc, mrq);
++}
++
++static
++bool bcm2835_send_command(struct bcm2835_host *host, struct mmc_command *cmd)
++{
++	struct device *dev = &host->pdev->dev;
++	u32 sdcmd, sdhsts;
++	unsigned long timeout;
++
++	WARN_ON(host->cmd);
++
++	sdcmd = bcm2835_read_wait_sdcmd(host, 100);
++	if (sdcmd & SDCMD_NEW_FLAG) {
++		dev_err(dev, "previous command never completed.\n");
++		bcm2835_dumpregs(host);
++		cmd->error = -EILSEQ;
++		bcm2835_finish_request(host);
++		return false;
++	}
++
++	if (!cmd->data && cmd->busy_timeout > 9000)
++		timeout = DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
++	else
++		timeout = 10 * HZ;
++	schedule_delayed_work(&host->timeout_work, timeout);
++
++	host->cmd = cmd;
++
++	/* Clear any error flags */
++	sdhsts = readl(host->ioaddr + SDHSTS);
++	if (sdhsts & SDHSTS_ERROR_MASK)
++		writel(sdhsts, host->ioaddr + SDHSTS);
++
++	if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
++		dev_err(dev, "unsupported response type!\n");
++		cmd->error = -EINVAL;
++		bcm2835_finish_request(host);
++		return false;
++	}
++
++	bcm2835_prepare_data(host, cmd);
++
++	writel(cmd->arg, host->ioaddr + SDARG);
++
++	sdcmd = cmd->opcode & SDCMD_CMD_MASK;
++
++	host->use_busy = false;
++	if (!(cmd->flags & MMC_RSP_PRESENT)) {
++		sdcmd |= SDCMD_NO_RESPONSE;
++	} else {
++		if (cmd->flags & MMC_RSP_136)
++			sdcmd |= SDCMD_LONG_RESPONSE;
++		if (cmd->flags & MMC_RSP_BUSY) {
++			sdcmd |= SDCMD_BUSYWAIT;
++			host->use_busy = true;
++		}
++	}
++
++	if (cmd->data) {
++		if (cmd->data->flags & MMC_DATA_WRITE)
++			sdcmd |= SDCMD_WRITE_CMD;
++		if (cmd->data->flags & MMC_DATA_READ)
++			sdcmd |= SDCMD_READ_CMD;
++	}
++
++	writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD);
++
++	return true;
++}
++
++static void bcm2835_transfer_complete(struct bcm2835_host *host)
++{
++	struct mmc_data *data;
++
++	WARN_ON(!host->data_complete);
++
++	data = host->data;
++	host->data = NULL;
++
++	/* Need to send CMD12 if -
++	 * a) open-ended multiblock transfer (no CMD23)
++	 * b) error in multiblock transfer
++	 */
++	if (host->mrq->stop && (data->error || !host->use_sbc)) {
++		if (bcm2835_send_command(host, host->mrq->stop)) {
++			/* No busy, so poll for completion */
++			if (!host->use_busy)
++				bcm2835_finish_command(host);
++		}
++	} else {
++		bcm2835_wait_transfer_complete(host);
++		bcm2835_finish_request(host);
++	}
++}
++
++static void bcm2835_finish_data(struct bcm2835_host *host)
++{
++	struct device *dev = &host->pdev->dev;
++	struct mmc_data *data;
++
++	data = host->data;
++
++	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
++	writel(host->hcfg, host->ioaddr + SDHCFG);
++
++	data->bytes_xfered = data->error ? 0 : (data->blksz * data->blocks);
++
++	host->data_complete = true;
++
++	if (host->cmd) {
++		/* Data managed to finish before the
++		 * command completed. Make sure we do
++		 * things in the proper order.
++		 */
++		dev_dbg(dev, "Finished early - HSTS %08x\n",
++			readl(host->ioaddr + SDHSTS));
++	} else {
++		bcm2835_transfer_complete(host);
++	}
++}
++
++static void bcm2835_finish_command(struct bcm2835_host *host)
++{
++	struct device *dev = &host->pdev->dev;
++	struct mmc_command *cmd = host->cmd;
++	u32 sdcmd;
++
++	sdcmd = bcm2835_read_wait_sdcmd(host, 100);
++
++	/* Check for errors */
++	if (sdcmd & SDCMD_NEW_FLAG) {
++		dev_err(dev, "command never completed.\n");
++		bcm2835_dumpregs(host);
++		host->cmd->error = -EIO;
++		bcm2835_finish_request(host);
++		return;
++	} else if (sdcmd & SDCMD_FAIL_FLAG) {
++		u32 sdhsts = readl(host->ioaddr + SDHSTS);
++
++		/* Clear the errors */
++		writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS);
++
++		if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
++		    (host->cmd->opcode != MMC_SEND_OP_COND)) {
++			if (sdhsts & SDHSTS_CMD_TIME_OUT) {
++				host->cmd->error = -ETIMEDOUT;
++			} else {
++				dev_err(dev, "unexpected command %d error\n",
++					host->cmd->opcode);
++				bcm2835_dumpregs(host);
++				host->cmd->error = -EILSEQ;
++			}
++			bcm2835_finish_request(host);
++			return;
++		}
++	}
++
++	if (cmd->flags & MMC_RSP_PRESENT) {
++		if (cmd->flags & MMC_RSP_136) {
++			int i;
++
++			for (i = 0; i < 4; i++) {
++				cmd->resp[3 - i] =
++					readl(host->ioaddr + SDRSP0 + i * 4);
++			}
++		} else {
++			cmd->resp[0] = readl(host->ioaddr + SDRSP0);
++		}
++	}
++
++	if (cmd == host->mrq->sbc) {
++		/* Finished CMD23, now send actual command. */
++		host->cmd = NULL;
++		if (bcm2835_send_command(host, host->mrq->cmd)) {
++			if (host->data && host->dma_desc)
++				/* DMA transfer starts now, PIO starts
++				 * after irq
++				 */
++				bcm2835_start_dma(host);
++
++			if (!host->use_busy)
++				bcm2835_finish_command(host);
++		}
++	} else if (cmd == host->mrq->stop) {
++		/* Finished CMD12 */
++		bcm2835_finish_request(host);
++	} else {
++		/* Processed actual command. */
++		host->cmd = NULL;
++		if (!host->data)
++			bcm2835_finish_request(host);
++		else if (host->data_complete)
++			bcm2835_transfer_complete(host);
++	}
++}
++
++static void bcm2835_timeout(struct work_struct *work)
++{
++	struct delayed_work *d = to_delayed_work(work);
++	struct bcm2835_host *host =
++		container_of(d, struct bcm2835_host, timeout_work);
++	struct device *dev = &host->pdev->dev;
++
++	mutex_lock(&host->mutex);
++
++	if (host->mrq) {
++		dev_err(dev, "timeout waiting for hardware interrupt.\n");
++		bcm2835_dumpregs(host);
++
++		if (host->data) {
++			host->data->error = -ETIMEDOUT;
++			bcm2835_finish_data(host);
++		} else {
++			if (host->cmd)
++				host->cmd->error = -ETIMEDOUT;
++			else
++				host->mrq->cmd->error = -ETIMEDOUT;
++
++			bcm2835_finish_request(host);
++		}
++	}
++
++	mutex_unlock(&host->mutex);
++}
++
++static bool bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
++{
++	struct device *dev = &host->pdev->dev;
++
++	if (!(intmask & SDHSTS_ERROR_MASK))
++		return false;
++
++	if (!host->cmd)
++		return true;
++
++	dev_err(dev, "sdhost_busy_irq: intmask %08x\n", intmask);
++	if (intmask & SDHSTS_CRC7_ERROR) {
++		host->cmd->error = -EILSEQ;
++	} else if (intmask & (SDHSTS_CRC16_ERROR |
++			      SDHSTS_FIFO_ERROR)) {
++		if (host->mrq->data)
++			host->mrq->data->error = -EILSEQ;
++		else
++			host->cmd->error = -EILSEQ;
++	} else if (intmask & SDHSTS_REW_TIME_OUT) {
++		if (host->mrq->data)
++			host->mrq->data->error = -ETIMEDOUT;
++		else
++			host->cmd->error = -ETIMEDOUT;
++	} else if (intmask & SDHSTS_CMD_TIME_OUT) {
++		host->cmd->error = -ETIMEDOUT;
++	}
++	bcm2835_dumpregs(host);
++	return true;
++}
++
++static void bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask)
++{
++	if (!host->data)
++		return;
++	if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR))
++		host->data->error = -EILSEQ;
++	if (intmask & SDHSTS_REW_TIME_OUT)
++		host->data->error = -ETIMEDOUT;
++}
++
++static void bcm2835_busy_irq(struct bcm2835_host *host)
++{
++	if (WARN_ON(!host->cmd)) {
++		bcm2835_dumpregs(host);
++		return;
++	}
++
++	if (WARN_ON(!host->use_busy)) {
++		bcm2835_dumpregs(host);
++		return;
++	}
++	host->use_busy = false;
++
++	bcm2835_finish_command(host);
++}
++
++static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
++{
++	/* There are no dedicated data/space available interrupt
++	 * status bits, so it is necessary to use the single shared
++	 * data/space available FIFO status bits. It is therefore not
++	 * an error to get here when there is no data transfer in
++	 * progress.
++	 */
++	if (!host->data)
++		return;
++
++	bcm2835_check_data_error(host, intmask);
++	if (host->data->error)
++		goto finished;
++
++	if (host->data->flags & MMC_DATA_WRITE) {
++		/* Use the block interrupt for writes after the first block */
++		host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
++		host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
++		writel(host->hcfg, host->ioaddr + SDHCFG);
++		bcm2835_transfer_pio(host);
++	} else {
++		bcm2835_transfer_pio(host);
++		host->blocks--;
++		if ((host->blocks == 0) || host->data->error)
++			goto finished;
++	}
++	return;
++
++finished:
++	host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
++	writel(host->hcfg, host->ioaddr + SDHCFG);
++}
++
++static void bcm2835_data_threaded_irq(struct bcm2835_host *host)
++{
++	if (!host->data)
++		return;
++	if ((host->blocks == 0) || host->data->error)
++		bcm2835_finish_data(host);
++}
++
++static void bcm2835_block_irq(struct bcm2835_host *host)
++{
++	if (WARN_ON(!host->data)) {
++		bcm2835_dumpregs(host);
++		return;
++	}
++
++	if (!host->dma_desc) {
++		WARN_ON(!host->blocks);
++		if (host->data->error || (--host->blocks == 0))
++			bcm2835_finish_data(host);
++		else
++			bcm2835_transfer_pio(host);
++	} else if (host->data->flags & MMC_DATA_WRITE) {
++		bcm2835_finish_data(host);
++	}
++}
++
++static irqreturn_t bcm2835_irq(int irq, void *dev_id)
++{
++	irqreturn_t result = IRQ_NONE;
++	struct bcm2835_host *host = dev_id;
++	u32 intmask;
++
++	spin_lock(&host->lock);
++
++	intmask = readl(host->ioaddr + SDHSTS);
++
++	writel(SDHSTS_BUSY_IRPT |
++	       SDHSTS_BLOCK_IRPT |
++	       SDHSTS_SDIO_IRPT |
++	       SDHSTS_DATA_FLAG,
++	       host->ioaddr + SDHSTS);
++
++	if (intmask & SDHSTS_BLOCK_IRPT) {
++		bcm2835_check_data_error(host, intmask);
++		host->irq_block = true;
++		result = IRQ_WAKE_THREAD;
++	}
++
++	if (intmask & SDHSTS_BUSY_IRPT) {
++		if (!bcm2835_check_cmd_error(host, intmask)) {
++			host->irq_busy = true;
++			result = IRQ_WAKE_THREAD;
++		} else {
++			result = IRQ_HANDLED;
++		}
++	}
++
++	/* There is no true data interrupt status bit, so it is
++	 * necessary to qualify the data flag with the interrupt
++	 * enable bit.
++	 */
++	if ((intmask & SDHSTS_DATA_FLAG) &&
++	    (host->hcfg & SDHCFG_DATA_IRPT_EN)) {
++		bcm2835_data_irq(host, intmask);
++		host->irq_data = true;
++		result = IRQ_WAKE_THREAD;
++	}
++
++	spin_unlock(&host->lock);
++
++	return result;
++}
++
++static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
++{
++	struct bcm2835_host *host = dev_id;
++	unsigned long flags;
++	bool block, busy, data;
++
++	spin_lock_irqsave(&host->lock, flags);
++
++	block = host->irq_block;
++	busy  = host->irq_busy;
++	data  = host->irq_data;
++	host->irq_block = false;
++	host->irq_busy  = false;
++	host->irq_data  = false;
++
++	spin_unlock_irqrestore(&host->lock, flags);
++
++	mutex_lock(&host->mutex);
++
++	if (block)
++		bcm2835_block_irq(host);
++	if (busy)
++		bcm2835_busy_irq(host);
++	if (data)
++		bcm2835_data_threaded_irq(host);
++
++	mutex_unlock(&host->mutex);
++
++	return IRQ_HANDLED;
++}
++
++static void bcm2835_dma_complete_work(struct work_struct *work)
++{
++	struct bcm2835_host *host =
++		container_of(work, struct bcm2835_host, dma_work);
++	struct mmc_data *data = host->data;
++
++	mutex_lock(&host->mutex);
++
++	if (host->dma_chan) {
++		dma_unmap_sg(host->dma_chan->device->dev,
++			     data->sg, data->sg_len,
++			     host->dma_dir);
++
++		host->dma_chan = NULL;
++	}
++
++	if (host->drain_words) {
++		unsigned long flags;
++		void *page;
++		u32 *buf;
++
++		if (host->drain_offset & PAGE_MASK) {
++			host->drain_page += host->drain_offset >> PAGE_SHIFT;
++			host->drain_offset &= ~PAGE_MASK;
++		}
++		local_irq_save(flags);
++		page = kmap_atomic(host->drain_page);
++		buf = page + host->drain_offset;
++
++		while (host->drain_words) {
++			u32 edm = readl(host->ioaddr + SDEDM);
++
++			if ((edm >> 4) & 0x1f)
++				*(buf++) = readl(host->ioaddr + SDDATA);
++			host->drain_words--;
++		}
++
++		kunmap_atomic(page);
++		local_irq_restore(flags);
++	}
++
++	bcm2835_finish_data(host);
++
++	mutex_unlock(&host->mutex);
++}
++
++static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
++{
++	int div;
++
++	/* The SDCDIV register has 11 bits, and holds (div - 2).  But
++	 * in data mode the max is 50MHz wihout a minimum, and only
++	 * the bottom 3 bits are used. Since the switch over is
++	 * automatic (unless we have marked the card as slow...),
++	 * chosen values have to make sense in both modes.  Ident mode
++	 * must be 100-400KHz, so can range check the requested
++	 * clock. CMD15 must be used to return to data mode, so this
++	 * can be monitored.
++	 *
++	 * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
++	 *                 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
++	 *
++	 *		 623->400KHz/27.8MHz
++	 *		 reset value (507)->491159/50MHz
++	 *
++	 * BUT, the 3-bit clock divisor in data mode is too small if
++	 * the core clock is higher than 250MHz, so instead use the
++	 * SLOW_CARD configuration bit to force the use of the ident
++	 * clock divisor at all times.
++	 */
++
++	if (clock < 100000) {
++		/* Can't stop the clock, but make it as slow as possible
++		 * to show willing
++		 */
++		host->cdiv = SDCDIV_MAX_CDIV;
++		writel(host->cdiv, host->ioaddr + SDCDIV);
++		return;
++	}
++
++	div = host->max_clk / clock;
++	if (div < 2)
++		div = 2;
++	if ((host->max_clk / div) > clock)
++		div++;
++	div -= 2;
++
++	if (div > SDCDIV_MAX_CDIV)
++		div = SDCDIV_MAX_CDIV;
++
++	clock = host->max_clk / (div + 2);
++	host->mmc->actual_clock = clock;
++
++	/* Calibrate some delays */
++
++	host->ns_per_fifo_word = (1000000000 / clock) *
++		((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
++
++	host->cdiv = div;
++	writel(host->cdiv, host->ioaddr + SDCDIV);
++
++	/* Set the timeout to 500ms */
++	writel(host->mmc->actual_clock / 2, host->ioaddr + SDTOUT);
++}
++
++static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
++{
++	struct bcm2835_host *host = mmc_priv(mmc);
++	struct device *dev = &host->pdev->dev;
++	u32 edm, fsm;
++
++	/* Reset the error statuses in case this is a retry */
++	if (mrq->sbc)
++		mrq->sbc->error = 0;
++	if (mrq->cmd)
++		mrq->cmd->error = 0;
++	if (mrq->data)
++		mrq->data->error = 0;
++	if (mrq->stop)
++		mrq->stop->error = 0;
++
++	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
++		dev_err(dev, "unsupported block size (%d bytes)\n",
++			mrq->data->blksz);
++		mrq->cmd->error = -EINVAL;
++		mmc_request_done(mmc, mrq);
++		return;
++	}
++
++	if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD))
++		bcm2835_prepare_dma(host, mrq->data);
++
++	mutex_lock(&host->mutex);
++
++	WARN_ON(host->mrq);
++	host->mrq = mrq;
++
++	edm = readl(host->ioaddr + SDEDM);
++	fsm = edm & SDEDM_FSM_MASK;
++
++	if ((fsm != SDEDM_FSM_IDENTMODE) &&
++	    (fsm != SDEDM_FSM_DATAMODE)) {
++		dev_err(dev, "previous command (%d) not complete (EDM %08x)\n",
++			readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK,
++			edm);
++		bcm2835_dumpregs(host);
++		mrq->cmd->error = -EILSEQ;
++		bcm2835_finish_request(host);
++		mutex_unlock(&host->mutex);
++		return;
++	}
++
++	host->use_sbc = !!mrq->sbc && (host->mrq->data->flags & MMC_DATA_READ);
++	if (host->use_sbc) {
++		if (bcm2835_send_command(host, mrq->sbc)) {
++			if (!host->use_busy)
++				bcm2835_finish_command(host);
++		}
++	} else if (bcm2835_send_command(host, mrq->cmd)) {
++		if (host->data && host->dma_desc) {
++			/* DMA transfer starts now, PIO starts after irq */
++			bcm2835_start_dma(host);
++		}
++
++		if (!host->use_busy)
++			bcm2835_finish_command(host);
++	}
++
++	mutex_unlock(&host->mutex);
++}
++
++static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
++{
++	struct bcm2835_host *host = mmc_priv(mmc);
++
++	mutex_lock(&host->mutex);
++
++	if (!ios->clock || ios->clock != host->clock) {
++		bcm2835_set_clock(host, ios->clock);
++		host->clock = ios->clock;
++	}
++
++	/* set bus width */
++	host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
++	if (ios->bus_width == MMC_BUS_WIDTH_4)
++		host->hcfg |= SDHCFG_WIDE_EXT_BUS;
++
++	host->hcfg |= SDHCFG_WIDE_INT_BUS;
++
++	/* Disable clever clock switching, to cope with fast core clocks */
++	host->hcfg |= SDHCFG_SLOW_CARD;
++
++	writel(host->hcfg, host->ioaddr + SDHCFG);
++
++	mutex_unlock(&host->mutex);
++}
++
++static struct mmc_host_ops bcm2835_ops = {
++	.request = bcm2835_request,
++	.set_ios = bcm2835_set_ios,
++	.hw_reset = bcm2835_reset,
++};
++
++static int bcm2835_add_host(struct bcm2835_host *host)
++{
++	struct mmc_host *mmc = host->mmc;
++	struct device *dev = &host->pdev->dev;
++	char pio_limit_string[20];
++	int ret;
++
++	mmc->f_max = host->max_clk;
++	mmc->f_min = host->max_clk / SDCDIV_MAX_CDIV;
++
++	mmc->max_busy_timeout = ~0 / (mmc->f_max / 1000);
++
++	dev_dbg(dev, "f_max %d, f_min %d, max_busy_timeout %d\n",
++		mmc->f_max, mmc->f_min, mmc->max_busy_timeout);
++
++	/* host controller capabilities */
++	mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
++		     MMC_CAP_NEEDS_POLL | MMC_CAP_HW_RESET | MMC_CAP_ERASE |
++		     MMC_CAP_CMD23;
++
++	spin_lock_init(&host->lock);
++	mutex_init(&host->mutex);
++
++	if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) {
++		dev_warn(dev, "unable to initialise DMA channel. Falling back to PIO\n");
++		host->use_dma = false;
++	} else {
++		host->use_dma = true;
++
++		host->dma_cfg_tx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
++		host->dma_cfg_tx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
++		host->dma_cfg_tx.slave_id = 13;		/* DREQ channel */
++		host->dma_cfg_tx.direction = DMA_MEM_TO_DEV;
++		host->dma_cfg_tx.src_addr = 0;
++		host->dma_cfg_tx.dst_addr = host->phys_addr + SDDATA;
++
++		host->dma_cfg_rx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
++		host->dma_cfg_rx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
++		host->dma_cfg_rx.slave_id = 13;		/* DREQ channel */
++		host->dma_cfg_rx.direction = DMA_DEV_TO_MEM;
++		host->dma_cfg_rx.src_addr = host->phys_addr + SDDATA;
++		host->dma_cfg_rx.dst_addr = 0;
++
++		if (dmaengine_slave_config(host->dma_chan_rxtx,
++					   &host->dma_cfg_tx) != 0 ||
++		    dmaengine_slave_config(host->dma_chan_rxtx,
++					   &host->dma_cfg_rx) != 0)
++			host->use_dma = false;
++	}
++
++	mmc->max_segs = 128;
++	mmc->max_req_size = 524288;
++	mmc->max_seg_size = mmc->max_req_size;
++	mmc->max_blk_size = 1024;
++	mmc->max_blk_count =  65535;
++
++	/* report supported voltage ranges */
++	mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
++
++	INIT_WORK(&host->dma_work, bcm2835_dma_complete_work);
++	INIT_DELAYED_WORK(&host->timeout_work, bcm2835_timeout);
++
++	/* Set interrupt enables */
++	host->hcfg = SDHCFG_BUSY_IRPT_EN;
++
++	bcm2835_reset_internal(host);
++
++	ret = request_threaded_irq(host->irq, bcm2835_irq,
++				   bcm2835_threaded_irq,
++				   0, mmc_hostname(mmc), host);
++	if (ret) {
++		dev_err(dev, "failed to request IRQ %d: %d\n", host->irq, ret);
++		return ret;
++	}
++
++	ret = mmc_add_host(mmc);
++	if (ret) {
++		free_irq(host->irq, host);
++		return ret;
++	}
++
++	pio_limit_string[0] = '\0';
++	if (host->use_dma && (PIO_THRESHOLD > 0))
++		sprintf(pio_limit_string, " (>%d)", PIO_THRESHOLD);
++	dev_info(dev, "loaded - DMA %s%s\n",
++		 host->use_dma ? "enabled" : "disabled", pio_limit_string);
++
++	return 0;
++}
++
++static int bcm2835_probe(struct platform_device *pdev)
++{
++	struct device *dev = &pdev->dev;
++	struct clk *clk;
++	struct resource *iomem;
++	struct bcm2835_host *host;
++	struct mmc_host *mmc;
++	const __be32 *regaddr_p;
++	int ret;
++
++	dev_dbg(dev, "%s\n", __func__);
++	mmc = mmc_alloc_host(sizeof(*host), dev);
++	if (!mmc)
++		return -ENOMEM;
++
++	mmc->ops = &bcm2835_ops;
++	host = mmc_priv(mmc);
++	host->mmc = mmc;
++	host->pdev = pdev;
++	spin_lock_init(&host->lock);
++
++	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++	host->ioaddr = devm_ioremap_resource(dev, iomem);
++	if (IS_ERR(host->ioaddr)) {
++		ret = PTR_ERR(host->ioaddr);
++		goto err;
++	}
++
++	/* Parse OF address directly to get the physical address for
++	 * DMA to our registers.
++	 */
++	regaddr_p = of_get_address(pdev->dev.of_node, 0, NULL, NULL);
++	if (!regaddr_p) {
++		dev_err(dev, "Can't get phys address\n");
++		ret = -EINVAL;
++		goto err;
++	}
++
++	host->phys_addr = be32_to_cpup(regaddr_p);
++
++	host->dma_chan = NULL;
++	host->dma_desc = NULL;
++
++	host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
++
++	clk = devm_clk_get(dev, NULL);
++	if (IS_ERR(clk)) {
++		ret = PTR_ERR(clk);
++		if (ret != -EPROBE_DEFER)
++			dev_err(dev, "could not get clk: %d\n", ret);
++		goto err;
++	}
++
++	host->max_clk = clk_get_rate(clk);
++
++	host->irq = platform_get_irq(pdev, 0);
++	if (host->irq <= 0) {
++		dev_err(dev, "get IRQ failed\n");
++		ret = -EINVAL;
++		goto err;
++	}
++
++	ret = mmc_of_parse(mmc);
++	if (ret)
++		goto err;
++
++	ret = bcm2835_add_host(host);
++	if (ret)
++		goto err;
++
++	platform_set_drvdata(pdev, host);
++
++	dev_dbg(dev, "%s -> OK\n", __func__);
++
++	return 0;
++
++err:
++	dev_dbg(dev, "%s -> err %d\n", __func__, ret);
++	mmc_free_host(mmc);
++
++	return ret;
++}
++
++static int bcm2835_remove(struct platform_device *pdev)
++{
++	struct bcm2835_host *host = platform_get_drvdata(pdev);
++
++	mmc_remove_host(host->mmc);
++
++	writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
++
++	free_irq(host->irq, host);
++
++	cancel_work_sync(&host->dma_work);
++	cancel_delayed_work_sync(&host->timeout_work);
++
++	mmc_free_host(host->mmc);
++	platform_set_drvdata(pdev, NULL);
++
++	return 0;
++}
++
++static const struct of_device_id bcm2835_match[] = {
++	{ .compatible = "brcm,bcm2835-sdhost" },
++	{ }
++};
++MODULE_DEVICE_TABLE(of, bcm2835_match);
++
++static struct platform_driver bcm2835_driver = {
++	.probe      = bcm2835_probe,
++	.remove     = bcm2835_remove,
++	.driver     = {
++		.name		= "sdhost-bcm2835",
++		.of_match_table	= bcm2835_match,
++	},
++};
++module_platform_driver(bcm2835_driver);
++
++MODULE_ALIAS("platform:sdhost-bcm2835");
++MODULE_DESCRIPTION("BCM2835 SDHost driver");
++MODULE_LICENSE("GPL v2");
++MODULE_AUTHOR("Phil Elwell");
diff --git a/target/linux/brcm2708/patches-4.9/080-0002-mmc-bcm2835-Fix-possible-NULL-ptr-dereference-in-bcm.patch b/target/linux/brcm2708/patches-4.9/080-0002-mmc-bcm2835-Fix-possible-NULL-ptr-dereference-in-bcm.patch
new file mode 100644
index 0000000000..f41bc9d379
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.9/080-0002-mmc-bcm2835-Fix-possible-NULL-ptr-dereference-in-bcm.patch
@@ -0,0 +1,30 @@
+From f6974cc20bb846169319b5dbe86fb2d79a002aa0 Mon Sep 17 00:00:00 2001
+From: Stefan Wahren <stefan.wahren at i2se.com>
+Date: Sat, 25 Mar 2017 13:17:00 +0000
+Subject: [PATCH] mmc: bcm2835: Fix possible NULL ptr dereference in
+ bcm2835_request
+
+This fixes a NULL pointer dereference in case of a MMC request with a
+set block count command and no data.
+
+Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
+Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
+Tested-by: Peter Robinson <pbrobinson at gmail.com>
+Reviewed-by: Jaehoon Chung <jh80.chung at samsung.com>
+Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
+---
+ drivers/mmc/host/bcm2835.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/drivers/mmc/host/bcm2835.c
++++ b/drivers/mmc/host/bcm2835.c
+@@ -1200,7 +1200,8 @@ static void bcm2835_request(struct mmc_h
+ 		return;
+ 	}
+ 
+-	host->use_sbc = !!mrq->sbc && (host->mrq->data->flags & MMC_DATA_READ);
++	host->use_sbc = !!mrq->sbc && host->mrq->data &&
++			(host->mrq->data->flags & MMC_DATA_READ);
+ 	if (host->use_sbc) {
+ 		if (bcm2835_send_command(host, mrq->sbc)) {
+ 			if (!host->use_busy)
diff --git a/target/linux/brcm2708/patches-4.9/080-0100-mmc-bcm2835-rename-Kconfig-symbol-to-avoid-downstrea.patch b/target/linux/brcm2708/patches-4.9/080-0100-mmc-bcm2835-rename-Kconfig-symbol-to-avoid-downstrea.patch
new file mode 100644
index 0000000000..d3178446ef
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.9/080-0100-mmc-bcm2835-rename-Kconfig-symbol-to-avoid-downstrea.patch
@@ -0,0 +1,40 @@
+From add1f1fc554efd32c08515ec1addcd2f23cb6b22 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal at milecki.pl>
+Date: Sat, 1 Apr 2017 14:36:31 +0200
+Subject: [PATCH] mmc: bcm2835: rename Kconfig symbol to avoid downstream
+ conflict
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Downstream Linux adds "alternative MMC driver" with MMC_BCM2835 symbol.
+Until it's resolved rename backported symbol.
+
+Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
+---
+ drivers/mmc/host/Kconfig  | 2 +-
+ drivers/mmc/host/Makefile | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+--- a/drivers/mmc/host/Kconfig
++++ b/drivers/mmc/host/Kconfig
+@@ -769,7 +769,7 @@ config MMC_TOSHIBA_PCI
+ 	depends on PCI
+ 	help
+ 
+-config MMC_BCM2835
++config MMC_BCM2835_UPSTREAM
+ 	tristate "Broadcom BCM2835 SDHOST MMC Controller support"
+ 	depends on ARCH_BCM2835 || COMPILE_TEST
+ 	depends on HAS_DMA
+--- a/drivers/mmc/host/Makefile
++++ b/drivers/mmc/host/Makefile
+@@ -57,7 +57,7 @@ obj-$(CONFIG_MMC_MOXART)	+= moxart-mmc.o
+ obj-$(CONFIG_MMC_SUNXI)		+= sunxi-mmc.o
+ obj-$(CONFIG_MMC_USDHI6ROL0)	+= usdhi6rol0.o
+ obj-$(CONFIG_MMC_TOSHIBA_PCI)	+= toshsd.o
+-obj-$(CONFIG_MMC_BCM2835)	+= bcm2835.o
++obj-$(CONFIG_MMC_BCM2835_UPSTREAM)	+= bcm2835.o
+ 
+ obj-$(CONFIG_MMC_REALTEK_PCI)	+= rtsx_pci_sdmmc.o
+ obj-$(CONFIG_MMC_REALTEK_USB)	+= rtsx_usb_sdmmc.o
-- 
2.11.0




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