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

Álvaro Fernández Rojas noltari at gmail.com
Thu Apr 13 16:00:17 PDT 2017


You only added CONFIG_MMC_BCM2835_UPSTREAM symbol for bcm2708, missing bcm2709 and bcm2710, which will break buildbot for those subtargets.

Apart from that, what's the purpose of adding a disabled driver?
Maybe you should create a branch in your staging repo in which this driver is enabled by default, in order to see if it works or not.

El 01/04/2017 a las 15:30, Rafał Miłecki escribió:
> 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
> 



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