[PATCH v2 0/8] mmc: bcm2835: Add new driver for the sdhost controller

[PATCH v2 0/8] mmc: bcm2835: Add new driver for the sdhost controller

[Gerd Hoffmann]

  Hi,

Next version if the bcm2835 sdhost patch series.
New in this version:
 * DMA fixed.
 * updated docs (kconfig, file comment, commit message) clarifying
   the two sd controller situation.
 * some code cleanups, as pointed out by Stefan.
 * dt bindings use mmc@... now.
 * added patches to update defconfigs.
 * added patch for rpi3 device tree, so wifi is actually enabled.

please review & test,
  Gerd

Eric Anholt (2):
  dt-bindings: Add binding for brcm,bcm2835-sdhost.
  mmc: bcm2835: Add new driver for the sdhost controller.

Gerd Hoffmann (6):
  mmc: bcm2835: add sdhost controller to devicetree
  arm: set CONFIG_MMC_BCM2835=y in bcm2835_defconfig
  arm: set CONFIG_MMC_BCM2835=y in multi_v7_defconfig
  arm64: set CONFIG_MMC_BCM2835=y in defconfig
  ARM: dts: bcm283x: switch from &sdhci to &sdhost
  ARM: dts: bcm2837: add &sdhci and &sdhost

 .../bindings/mmc/brcm,bcm2835-sdhost.txt           |   24 +
 arch/arm/boot/dts/bcm2835-rpi.dtsi                 |    6 +
 arch/arm/boot/dts/bcm283x.dtsi                     |   10 +
 arch/arm/configs/bcm2835_defconfig                 |    1 +
 arch/arm/configs/multi_v7_defconfig                |    1 +
 arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts   |   17 +
 arch/arm64/configs/defconfig                       |    1 +
 drivers/mmc/host/Kconfig                           |   14 +
 drivers/mmc/host/Makefile                          |    1 +
 drivers/mmc/host/bcm2835.c                         | 1521 ++++++++++++++++++++
 10 files changed, 1596 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/brcm,bcm2835-sdhost.txt
 create mode 100644 drivers/mmc/host/bcm2835.c

-- 
1.8.3.1

[PATCH v2 1/8] dt-bindings: Add binding for brcm,bcm2835-sdhost.

[Gerd Hoffmann]

From: Eric Anholt <eric@anholt.net>

This is the other SD controller on the platform, which can be swapped
to the role of SD card host using pin muxing.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mmc/brcm,bcm2835-sdhost.txt           | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/brcm,bcm2835-sdhost.txt

diff --git a/Documentation/devicetree/bindings/mmc/brcm,bcm2835-sdhost.txt b/Documentation/devicetree/bindings/mmc/brcm,bcm2835-sdhost.txt
new file mode 100644
index 0000000..ac676db
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/brcm,bcm2835-sdhost.txt
@@ -0,0 +1,24 @@
+Broadcom BCM2835 SDHOST controller
+
+This file documents differences between the core properties described
+by mmc.txt and the properties that represent the BCM2835 controller.
+
+Required properties:
+- compatible: Should be "brcm,bcm2835-sdhost".
+- clocks: The clock feeding the SDHOST controller.
+
+Optional properties:
+- dmas: DMA channels for read and write.
+          See Documentation/devicetree/bindings/dma/dma.txt for details
+
+Example:
+
+sdhost: mmc@7e202000 {
+	compatible = "brcm,bcm2835-sdhost";
+	reg = <0x7e202000 0x100>;
+	interrupts = <2 24>;
+	clocks = <&clocks BCM2835_CLOCK_VPU>;
+	dmas = <&dma 13>,
+	       <&dma 13>;
+	dma-names = "tx", "rx";
+};
-- 
1.8.3.1

[PATCH v2 2/8] mmc: bcm2835: Add new driver for the sdhost controller.

[Gerd Hoffmann]

From: Eric Anholt <eric@anholt.net>

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, and I did a major cleanup on it (+319, -707 lines
out of the original 2055) for inclusion.

Signed-off-by: Eric Anholt <eric@anholt.net>

cleanups by Gerd Hoffmann

mmc: bcm2835: zap mmiowb()
mmc: bcm2835: reset tweaks.
mmc: bcm2835: more reset tweaks.
mmc: bcm2835: rename bcm2835_sdhost to bcm2835
mmc: bcm2835: whitespace & comment style
mmc: bcm2835: zap bcm2835_write
mmc: bcm2835: zap bcm2835_read
mmc: bcm2835: zap bcm2835_read_relaxed
mmc: bcm2835: zap bcm2835_set_ios fwd decl
mmc: bcm2835: use dev_dbg()
mmc: bcm2835: use dev_err()
mmc: bcm2835: use dev_warn() + dev_into()

cleanups by Stefan Wahren

mmc: bcm2835: Fix checkpatch.pl warning
mmc: bcm2835: replace spaces with tabs
mmc: bcm2835: remove bcm2835_set_power
mmc: bcm2835: remove bcm2835_init()
mmc: bcm2835: Avoid separate init statement
mmc: bcm2835: Use local device ptr to make code more compact
mmc: bcm2835: Use local ptr to make code more compact
mmc: bcm2835: Use __func__ macro
mmc: bcm2835: sort includes alphabetical
mmc: bcm2835: fix includes
mmc: bcm2835: refactor bcm2835_wait_transfer_complete()
mmc: bcm2835: Handle error case of of_get_address
mmc: bcm2835: Use MMC_SEND_OP_COND instead of number
mmc: bcm2835: Rearrange mmc capabilities

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>

driver modernizations:
 * run most driver code in thread context.
   - use threaded irq handler.
   - schedule worker for timeout handling.
 * use mutex for locking, so we can easily sleep.
 * simplify poll/wait code, drop tasklet and work queue.
 * fix DMA support.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/mmc/host/Kconfig   |   14 +
 drivers/mmc/host/Makefile  |    1 +
 drivers/mmc/host/bcm2835.c | 1521 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1536 insertions(+)
 create mode 100644 drivers/mmc/host/bcm2835.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 2eb9701..ae5b2e7 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -790,6 +790,20 @@ config MMC_TOSHIBA_PCI
 	depends on PCI
 	help
 
+config MMC_BCM2835
+	tristate "platform support for the BCM2835 SDHOST MMC Controller"
+	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
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index ccc9c4c..1a8fbab 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -58,6 +58,7 @@ 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
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
new file mode 100644
index 0000000..5ea8bd6
--- /dev/null
+++ b/drivers/mmc/host/bcm2835.c
@@ -0,0 +1,1521 @@
+/*
+ * 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@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/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   */
+#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 CMD_DALLY_US		1
+
+struct bcm2835_host {
+	spinlock_t		lock;
+	struct mutex            mutex;
+
+	void __iomem		*ioaddr;
+	u32			phys_addr;
+
+	struct mmc_host		*mmc;
+	struct platform_device	*pdev;
+
+	u32			pio_timeout;	/* In jiffies */
+	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			flush_fifo:1;	/* Drain the fifo when finish */
+	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_rx;
+	struct dma_chan		*dma_chan_tx;
+	struct dma_chan		*dma_chan;
+	struct dma_async_tx_descriptor	*dma_desc;
+	u32			dma_dir;
+	u32			drain_words;
+	struct page		*drain_page;
+	u32			drain_offset;
+	bool			use_dma;
+
+	int	max_delay;	/* maximum length of time spent waiting */
+	u32	pio_limit;	/* Maximum block count for PIO (0 = 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_data(struct bcm2835_host *host);
+static void bcm2835_finish_command(struct bcm2835_host *host);
+static void bcm2835_finish_request(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_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_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, len;
+	u32 *buf;
+	unsigned long wait_max;
+
+	blksize = host->data->blksz;
+
+	wait_max = jiffies + msecs_to_jiffies(host->pio_timeout);
+
+	local_irq_save(flags);
+
+	while (blksize) {
+		int copy_words;
+		u32 hsts = 0;
+
+		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 = SDDATA_FIFO_PIO_BURST;
+			if (burst_words > copy_words)
+				burst_words = 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 %x\n",
+						fsm_state, hsts);
+					if (hsts & SDHSTS_ERROR_MASK)
+						break;
+				}
+
+				if (time_after(jiffies, wait_max)) {
+					dev_err(dev, "PIO %s timeout - EDM %x\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 %x\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 %x\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;
+
+	dev_dbg(&host->pdev->dev, "bcm2835_prepare_dma()\n");
+
+	if (data->flags & MMC_DATA_READ) {
+		dma_chan = host->dma_chan_rx;
+		dir_data = DMA_FROM_DEVICE;
+		dir_slave = DMA_DEV_TO_MEM;
+	} else {
+		dma_chan = host->dma_chan_tx;
+		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;
+	}
+
+	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->flush_fifo = 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,
+				   bool check_fail)
+{
+	struct device *dev = &host->pdev->dev;
+	u32 value;
+	int ret;
+
+	ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
+				 (!(value & SDCMD_NEW_FLAG)) ||
+				 (check_fail && (value & SDCMD_FAIL_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)) ||
+					 (check_fail && (value & SDCMD_FAIL_FLAG)),
+					 10, max_ms * 1000);
+	if (ret == -ETIMEDOUT)
+		dev_err(dev, "%s: timeout (%d ms)\n",
+			__func__, max_ms);
+
+	return value;
+}
+
+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);
+
+	if (cmd->data) {
+		dev_dbg(dev, "send_command %d 0x%x (flags 0x%x) - %s %d*%d\n",
+			cmd->opcode, cmd->arg, cmd->flags,
+			(cmd->data->flags & MMC_DATA_READ) ?
+			"read" : "write", cmd->data->blocks,
+			cmd->data->blksz);
+	} else {
+		dev_dbg(dev, "send_command %d 0x%x (flags 0x%x)\n",
+			cmd->opcode, cmd->arg, cmd->flags);
+	}
+
+	sdcmd = bcm2835_read_wait_sdcmd(host, 100, false);
+	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;
+
+	dev_dbg(&host->pdev->dev, "transfer_complete(error %d, stop %d)\n",
+		data->error, data->stop ? 1 : 0);
+
+	/* 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;
+
+	dev_dbg(dev, "finish_data(error %d, stop %d, sbc %d)\n",
+		data->error, data->stop ? 1 : 0,
+		host->mrq->sbc ? 1 : 0);
+
+	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 %x\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;
+
+	dev_dbg(dev, "finish_command(%x)\n", readl(host->ioaddr + SDCMD));
+
+	sdcmd = bcm2835_read_wait_sdcmd(host, 100, true);
+
+	/* 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);
+			}
+
+			dev_dbg(dev, "finish_command %08x %08x %08x %08x\n",
+				cmd->resp[0], cmd->resp[1],
+				cmd->resp[2], cmd->resp[3]);
+		} else {
+			cmd->resp[0] = readl(host->ioaddr + SDRSP0);
+			dev_dbg(dev, "finish_command %08x\n", cmd->resp[0]);
+		}
+	}
+
+	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;
+
+			dev_dbg(dev, "timeout_timer tasklet_schedule\n");
+			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 %x, data %p\n",
+		intmask, host->mrq->data);
+	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);
+	return;
+}
+
+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;
+}
+
+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 > host->pio_limit))
+		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 %x)\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 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);
+}
+
+int bcm2835_add_host(struct bcm2835_host *host)
+{
+	struct mmc_host *mmc = host->mmc;
+	struct device *dev = &host->pdev->dev;
+	struct dma_slave_config cfg;
+	char pio_limit_string[20];
+	int ret;
+
+	bcm2835_reset_internal(host);
+
+	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_tx) ||
+	    IS_ERR_OR_NULL(host->dma_chan_rx)) {
+		dev_err(dev, "unable to initialise DMA channels. Falling back to PIO\n");
+		host->use_dma = false;
+	} else {
+		host->use_dma = true;
+
+		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+		cfg.slave_id = 13;		/* DREQ channel */
+
+		cfg.direction = DMA_MEM_TO_DEV;
+		cfg.src_addr = 0;
+		cfg.dst_addr = host->phys_addr + SDDATA;
+		ret = dmaengine_slave_config(host->dma_chan_tx, &cfg);
+		if (ret)
+			host->use_dma = false;
+
+		cfg.direction = DMA_DEV_TO_MEM;
+		cfg.src_addr = host->phys_addr + SDDATA;
+		cfg.dst_addr = 0;
+		ret = dmaengine_slave_config(host->dma_chan_rx, &cfg);
+		if (ret)
+			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 = 512;
+	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;
+	}
+
+	mmc_add_host(mmc);
+
+	pio_limit_string[0] = '\0';
+	if (host->use_dma && (host->pio_limit > 0))
+		sprintf(pio_limit_string, " (>%d)", host->pio_limit);
+	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;
+	host->pio_timeout = msecs_to_jiffies(500);
+	host->pio_limit = 1;
+	host->max_delay = 1; /* Warn if over 1ms */
+	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);
+
+	dev_dbg(dev, " - ioaddr %lx, iomem->start %lx, phys_addr %lx\n",
+		(unsigned long)host->ioaddr,
+		(unsigned long)iomem->start,
+		(unsigned long)host->phys_addr);
+
+	host->dma_chan = NULL;
+	host->dma_desc = NULL;
+
+	host->dma_chan_tx = dma_request_slave_channel(dev, "tx");
+	host->dma_chan_rx = dma_request_slave_channel(dev, "rx");
+
+	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;
+	}
+
+	dev_dbg(dev, " - max_clk %lx, irq %d\n",
+		(unsigned long)host->max_clk,
+		(int)host->irq);
+
+	mmc_of_parse(mmc);
+
+	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);
+
+	dev_dbg(&pdev->dev, "%s\n", __func__);
+
+	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);
+
+	dev_dbg(&pdev->dev, "%s - OK\n", __func__);
+	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");
-- 
1.8.3.1

[PATCH v2 3/8] mmc: bcm2835: add sdhost controller to devicetree

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 arch/arm/boot/dts/bcm2835-rpi.dtsi |  6 ++++++
 arch/arm/boot/dts/bcm283x.dtsi     | 10 ++++++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
index 0b73f9c..7d89af2 100644
--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
@@ -69,6 +69,12 @@
 	bus-width = <4>;
 };
 
+&sdhost {
+	pinctrl-names = "default";
+	pinctrl-0 = <&sdhost_gpio48>;
+	bus-width = <4>;
+};
+
 &pwm {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pwm0_gpio40 &pwm1_gpio45>;
diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index a3106aa..180f359 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -450,6 +450,16 @@
 			status = "disabled";
 		};
 
+		sdhost: mmc@7e202000 {
+			compatible = "brcm,bcm2835-sdhost";
+			reg = <0x7e202000 0x100>;
+			interrupts = <2 24>;
+			clocks = <&clocks BCM2835_CLOCK_VPU>;
+			dmas = <&dma 13>, <&dma 13>;
+			dma-names = "tx", "rx";
+			status = "disabled";
+		};
+
 		hvs@7e400000 {
 			compatible = "brcm,bcm2835-hvs";
 			reg = <0x7e400000 0x6000>;
-- 
1.8.3.1

[PATCH v2 4/8] arm: set CONFIG_MMC_BCM2835=y in bcm2835_defconfig

[Gerd Hoffmann]

---
 arch/arm/configs/bcm2835_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/bcm2835_defconfig b/arch/arm/configs/bcm2835_defconfig
index 4b89f4e..3767c24 100644
--- a/arch/arm/configs/bcm2835_defconfig
+++ b/arch/arm/configs/bcm2835_defconfig
@@ -92,6 +92,7 @@ CONFIG_MMC=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_PLTFM=y
 CONFIG_MMC_SDHCI_IPROC=y
+CONFIG_MMC_BCM2835=y
 CONFIG_NEW_LEDS=y
 CONFIG_LEDS_CLASS=y
 CONFIG_LEDS_GPIO=y
-- 
1.8.3.1

[PATCH v2 5/8] arm: set CONFIG_MMC_BCM2835=y in multi_v7_defconfig

[Gerd Hoffmann]

---
 arch/arm/configs/multi_v7_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/multi_v7_defconfig b/arch/arm/configs/multi_v7_defconfig
index 028d2b7..5d13894 100644
--- a/arch/arm/configs/multi_v7_defconfig
+++ b/arch/arm/configs/multi_v7_defconfig
@@ -727,6 +727,7 @@ CONFIG_MMC_DW_EXYNOS=y
 CONFIG_MMC_DW_ROCKCHIP=y
 CONFIG_MMC_SH_MMCIF=y
 CONFIG_MMC_SUNXI=y
+CONFIG_MMC_BCM2835=y
 CONFIG_NEW_LEDS=y
 CONFIG_LEDS_CLASS=y
 CONFIG_LEDS_CLASS_FLASH=m
-- 
1.8.3.1

[PATCH v2 6/8] arm64: set CONFIG_MMC_BCM2835=y in defconfig

[Gerd Hoffmann]

---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 33b744d..75131a6 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -391,6 +391,7 @@ CONFIG_MMC_DW_EXYNOS=y
 CONFIG_MMC_DW_K3=y
 CONFIG_MMC_DW_ROCKCHIP=y
 CONFIG_MMC_SUNXI=y
+CONFIG_MMC_BCM2835=y
 CONFIG_NEW_LEDS=y
 CONFIG_LEDS_CLASS=y
 CONFIG_LEDS_GPIO=y
-- 
1.8.3.1

[PATCH v2 7/8] ARM: dts: bcm283x: switch from &sdhci to &sdhost

[Gerd Hoffmann]

sdcard access with the sdhost controller is faster.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 arch/arm/boot/dts/bcm2835-rpi.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
index 7d89af2..e6beecb 100644
--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
@@ -65,13 +65,13 @@
 &sdhci {
 	pinctrl-names = "default";
 	pinctrl-0 = <&emmc_gpio48>;
-	status = "okay";
 	bus-width = <4>;
 };
 
 &sdhost {
 	pinctrl-names = "default";
 	pinctrl-0 = <&sdhost_gpio48>;
+	status = "okay";
 	bus-width = <4>;
 };
 
-- 
1.8.3.1

[PATCH v2 8/8] ARM: dts: bcm2837: add &sdhci and &sdhost

[Gerd Hoffmann]

For the raspberry pi 3 we'll need both sdhci (handles sdio wifi) and
sdhost (handles sdcard).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts b/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
index c309633..972f14d 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
+++ b/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
@@ -22,3 +22,20 @@
 &uart1 {
 	status = "okay";
 };
+
+/* SDHCI is used to control the SDIO for wireless */
+&sdhci {
+	pinctrl-names = "default";
+	pinctrl-0 = <&emmc_gpio34>;
+	status = "okay";
+	bus-width = <4>;
+	non-removable;
+};
+
+/* SDHOST is used to drive the SD card */
+&sdhost {
+	pinctrl-names = "default";
+	pinctrl-0 = <&sdhost_gpio48>;
+	status = "okay";
+	bus-width = <4>;
+};
-- 
1.8.3.1

Re: [PATCH v2 4/8] arm: set CONFIG_MMC_BCM2835=y in bcm2835_defconfig

[Eric Anholt]

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Gerd Hoffmann <kraxel@redhat.com> writes:

> ---
>  arch/arm/configs/bcm2835_defconfig | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/configs/bcm2835_defconfig b/arch/arm/configs/bcm2835_defconfig
> index 4b89f4e..3767c24 100644
> --- a/arch/arm/configs/bcm2835_defconfig
> +++ b/arch/arm/configs/bcm2835_defconfig
> @@ -92,6 +92,7 @@ CONFIG_MMC=y
>  CONFIG_MMC_SDHCI=y
>  CONFIG_MMC_SDHCI_PLTFM=y
>  CONFIG_MMC_SDHCI_IPROC=y
> +CONFIG_MMC_BCM2835=y
>  CONFIG_NEW_LEDS=y
>  CONFIG_LEDS_CLASS=y
>  CONFIG_LEDS_GPIO=y

If you end up resubmitting this, could you extend the commit message of
the defconfig changes to explain why it's being done?  Something like:

"We need to enable this controller so that we can switch the SD card's
pinmux over to it by default, which will improve storage read/write
speed."

(even better if we have some sort of stats on how much better it is).

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Re: [PATCH v2 3/8] mmc: bcm2835: add sdhost controller to devicetree

[Eric Anholt]

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Gerd Hoffmann <kraxel@redhat.com> writes:

> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Patches 3, 7, 8 are:

Acked-by: Eric Anholt <eric@anholt.net>

waiting on Ulf for merging the driver now.

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Re: [PATCH v2 2/8] mmc: bcm2835: Add new driver for the sdhost controller.

[Stefan Wahren]

Hi Gerd,

first of all here my wishlist for the next round of this driver:
* compile test the series with ARM and ARM64
* add me in CC for all patches of the series
* run checkpatch.pl before submission
* apply the patch series to your cgit repo

> Gerd Hoffmann <kraxel@redhat.com> hat am 3. Februar 2017 um 13:11 geschrieben:
> 
> 
> From: Eric Anholt <eric@anholt.net>
> 
> 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

Sorry, for the confusion. I was wrong. According to the registers the SDHOST should also support SDIO. It's a feature we could implement later.

> 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, and I did a major cleanup on it (+319, -707 lines
> out of the original 2055) for inclusion.

I think it would be helpful to known the downstream commit, because this commit [1]
doesn't seem to be included.

[1] - https://github.com/raspberrypi/linux/commit/ea4b1c5c2ddbb6caba43ab9b0103542a4ca7e1f0

I've found and fixed a lot of issues in this version and i think it would be better if i send you the patches for squashing them all together. Here is the preview for my patch series:

Stefan Wahren (15):
  mmc: bcm2835: Add missing include for threaded irq
  mmc: bcm2835: Remove CMD_DALLY_US
  mmc: bcm2835: Fix pio_timeout handling
  mmc: bcm2835: Remove unnecessary return in bcm2835_data_irq
  mmc: bcm2835: Handle error cases during probe
  mmc: bcm2835: Print clk_max as decimal
  mmc: bcm2835: Downrate message in case of PIO fallback
  mmc: bcm2835: Don't unveil the data pointer
  mmc: bcm2835: remove unused host members
  mmc: bcm2835: Avoid unnecessary linebreaks
  mmc: bcm2835: Add leading zero to register dumps
  mmc: bcm2835: Align struct members with tabs
  mmc: bcm2835: Rearrange bcm2835_finish_request()
  mmc: bcm2835: Rearrange bcm2835_dma_complete_work()
  mmc: bcm2835: Rename Kconfig switch

I'll send it after my tests. In the following review i will mention only the issues which aren't fixed in my patch series.

> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
> new file mode 100644
> index 0000000..5ea8bd6
> --- /dev/null
> +++ b/drivers/mmc/host/bcm2835.c
> @@ -0,0 +1,1521 @@
> +/*
> + * 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@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/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   */
> +#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 CMD_DALLY_US		1
> +
> +struct bcm2835_host {
> +	spinlock_t		lock;
> +	struct mutex            mutex;

Would be nice to have a comment for the lock and mutex.

> +
> +	void __iomem		*ioaddr;
> +	u32			phys_addr;
> +
> +	struct mmc_host		*mmc;
> +	struct platform_device	*pdev;
> +
> +	u32			pio_timeout;	/* In jiffies */
> +	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			flush_fifo:1;	/* Drain the fifo when finish */
> +	bool			use_busy:1;	/* Wait for busy interrupt */
> +	bool			use_sbc:1;	/* Send CMD23 */

It would be nice to get the rid off use_busy and use_sbc. Do you see any chance for use_busy?

> +
> +	/* for threaded irq handler */
> +	bool                    irq_block;
> +	bool                    irq_busy;
> +	bool                    irq_data;
> +
> +	/* DMA part */
> +	struct dma_chan		*dma_chan_rx;
> +	struct dma_chan		*dma_chan_tx;
> +	struct dma_chan		*dma_chan;
> +	struct dma_async_tx_descriptor	*dma_desc;
> +	u32			dma_dir;
> +	u32			drain_words;
> +	struct page		*drain_page;
> +	u32			drain_offset;
> +	bool			use_dma;
> +
> +	int	max_delay;	/* maximum length of time spent waiting */
> +	u32	pio_limit;	/* Maximum block count for PIO (0 = 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 */

Any chance to eliminate the bit magic for SDTOUT and SDHSTS?

> +	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_finish_data(struct bcm2835_host *host)
> +{
> +	struct device *dev = &host->pdev->dev;
> +	struct mmc_data *data;
> +
> +	data = host->data;
> +
> +	dev_dbg(dev, "finish_data(error %d, stop %d, sbc %d)\n",
> +		data->error, data->stop ? 1 : 0,
> +		host->mrq->sbc ? 1 : 0);
> +
> +	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 %x\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;
> +
> +	dev_dbg(dev, "finish_command(%x)\n", readl(host->ioaddr + SDCMD));
> +
> +	sdcmd = bcm2835_read_wait_sdcmd(host, 100, true);
> +
> +	/* 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);
> +			}
> +
> +			dev_dbg(dev, "finish_command %08x %08x %08x %08x\n",
> +				cmd->resp[0], cmd->resp[1],
> +				cmd->resp[2], cmd->resp[3]);
> +		} else {
> +			cmd->resp[0] = readl(host->ioaddr + SDRSP0);
> +			dev_dbg(dev, "finish_command %08x\n", cmd->resp[0]);
> +		}
> +	}
> +
> +	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);

Recursion?

> +		}
> +	} 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);

bcm2835_finish_command() calls bcm2835_transfer_complete()
bcm2835_transfer_complete() calls bcm2835_finish_command()

This should be avoided.

> ...
> +int bcm2835_add_host(struct bcm2835_host *host)
> +{
> +	struct mmc_host *mmc = host->mmc;
> +	struct device *dev = &host->pdev->dev;
> +	struct dma_slave_config cfg;
> +	char pio_limit_string[20];
> +	int ret;
> +
> +	bcm2835_reset_internal(host);
> +
> +	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_tx) ||
> +	    IS_ERR_OR_NULL(host->dma_chan_rx)) {
> +		dev_err(dev, "unable to initialise DMA channels. Falling back to PIO\n");
> +		host->use_dma = false;
> +	} else {
> +		host->use_dma = true;
> +
> +		cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> +		cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> +		cfg.slave_id = 13;		/* DREQ channel */

Is this the same value which is also defined in the DT?

Thanks
Stefan

Re: [PATCH v2 2/8] mmc: bcm2835: Add new driver for the sdhost controller.

[Gerd Hoffmann]

On Mo, 2017-02-06 at 21:34 +0100, Stefan Wahren wrote:
> Hi Gerd,
> 
> first of all here my wishlist for the next round of this driver:
> * compile test the series with ARM and ARM64

It is tested on both arm and arm64 (rpi2 + rpi3).

> * add me in CC for all patches of the series

Oops.  /me should be more careful when reading names.  I thought I had
you on Cc:  Double-checked.  Turned out that was Stephen Warren ...

> * run checkpatch.pl before submission

Hmm?  Are there any issues?  /me has a pre-commit hook running
checkpatch to avoid anything slipping though.

> * apply the patch series to your cgit repo

Branch pushed now: bcm2837-sdhost-squashed-v2

> > The sdhci controller supports both sdcard and sdio.  The sdhost
> > controller supports the sdcard only, but has better performance.  Also
> 
> Sorry, for the confusion. I was wrong. According to the registers the SDHOST should also support SDIO. It's a feature we could implement later.

Ok.

> > 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, and I did a major cleanup on it (+319, -707 lines
> > out of the original 2055) for inclusion.
> 
> I think it would be helpful to known the downstream commit, because this commit [1]
> doesn't seem to be included.
> 
> [1] - https://github.com/raspberrypi/linux/commit/ea4b1c5c2ddbb6caba43ab9b0103542a4ca7e1f0
> 
> I've found and fixed a lot of issues in this version and i think it would be better if i send you the patches for squashing them all together. Here is the preview for my patch series:
> 
> Stefan Wahren (15):
>   mmc: bcm2835: Add missing include for threaded irq
>   mmc: bcm2835: Remove CMD_DALLY_US
>   mmc: bcm2835: Fix pio_timeout handling
>   mmc: bcm2835: Remove unnecessary return in bcm2835_data_irq
>   mmc: bcm2835: Handle error cases during probe
>   mmc: bcm2835: Print clk_max as decimal
>   mmc: bcm2835: Downrate message in case of PIO fallback
>   mmc: bcm2835: Don't unveil the data pointer
>   mmc: bcm2835: remove unused host members
>   mmc: bcm2835: Avoid unnecessary linebreaks
>   mmc: bcm2835: Add leading zero to register dumps
>   mmc: bcm2835: Align struct members with tabs
>   mmc: bcm2835: Rearrange bcm2835_finish_request()
>   mmc: bcm2835: Rearrange bcm2835_dma_complete_work()
>   mmc: bcm2835: Rename Kconfig switch
> 
> I'll send it after my tests. In the following review i will mention only the issues which aren't fixed in my patch series.

I'll pick up the patches and look at the remaining issues, new version
later this week (i hope).

thanks,
  Gerd

Re: [PATCH v2 2/8] mmc: bcm2835: Add new driver for the sdhost controller.

[Stefan Wahren]

Hi Gerd,

Am 07.02.2017 um 09:02 schrieb Gerd Hoffmann:
> On Mo, 2017-02-06 at 21:34 +0100, Stefan Wahren wrote:
>> Hi Gerd,
>>
>> first of all here my wishlist for the next round of this driver:
>> * compile test the series with ARM and ARM64
> It is tested on both arm and arm64 (rpi2 + rpi3).

i got implicite declaration for request_threaded_irq() and free_irq().
After including linux/interrupt.h the issue is fixed (patch #1 of my
series).

>
>> * add me in CC for all patches of the series
> Oops.  /me should be more careful when reading names.  I thought I had
> you on Cc:  Double-checked.  Turned out that was Stephen Warren ...

No problem

>
>> * run checkpatch.pl before submission
> Hmm?  Are there any issues?  /me has a pre-commit hook running
> checkpatch to avoid anything slipping though.

Just a single issue about a unnecessary return at the end of
bcm2835_data_irq() (patch #4 of my series). Maybe this was a new rule.

>
>> * apply the patch series to your cgit repo
> Branch pushed now: bcm2837-sdhost-squashed-v2

Thanks

>
>>> The sdhci controller supports both sdcard and sdio.  The sdhost
>>> controller supports the sdcard only, but has better performance.  Also
>> Sorry, for the confusion. I was wrong. According to the registers the SDHOST should also support SDIO. It's a feature we could implement later.
> Ok.
>
>>> 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, and I did a major cleanup on it (+319, -707 lines
>>> out of the original 2055) for inclusion.
>> I think it would be helpful to known the downstream commit, because this commit [1]
>> doesn't seem to be included.
>>
>> [1] - https://github.com/raspberrypi/linux/commit/ea4b1c5c2ddbb6caba43ab9b0103542a4ca7e1f0

Sorry wrong link, this must be the right one

https://github.com/raspberrypi/linux/commit/1131510a589ae7262b8861af8d2f4a000710d59c

>>
>> I've found and fixed a lot of issues in this version and i think it would be better if i send you the patches for squashing them all together. Here is the preview for my patch series:
>>
>> Stefan Wahren (15):
>>   mmc: bcm2835: Add missing include for threaded irq
>>   mmc: bcm2835: Remove CMD_DALLY_US
>>   mmc: bcm2835: Fix pio_timeout handling
>>   mmc: bcm2835: Remove unnecessary return in bcm2835_data_irq
>>   mmc: bcm2835: Handle error cases during probe
>>   mmc: bcm2835: Print clk_max as decimal
>>   mmc: bcm2835: Downrate message in case of PIO fallback
>>   mmc: bcm2835: Don't unveil the data pointer
>>   mmc: bcm2835: remove unused host members
>>   mmc: bcm2835: Avoid unnecessary linebreaks
>>   mmc: bcm2835: Add leading zero to register dumps
>>   mmc: bcm2835: Align struct members with tabs
>>   mmc: bcm2835: Rearrange bcm2835_finish_request()
>>   mmc: bcm2835: Rearrange bcm2835_dma_complete_work()
>>   mmc: bcm2835: Rename Kconfig switch
>>
>> I'll send it after my tests. In the following review i will mention only the issues which aren't fixed in my patch series.
> I'll pick up the patches and look at the remaining issues, new version
> later this week (i hope).
>
> thanks,
>   Gerd

Re: [PATCH v2 2/8] mmc: bcm2835: Add new driver for the sdhost controller.

[Stefan Wahren]

> Gerd Hoffmann <kraxel@redhat.com> hat am 7. Februar 2017 um 09:02 geschrieben:
> ...
> > 
> > I'll send it after my tests. In the following review i will mention only the issues which aren't fixed in my patch series.
> 
> I'll pick up the patches and look at the remaining issues, new version
> later this week (i hope).

No need to hurry. The merge window opens soon.

Do you take care of the missing downstream patch ( bcm2835-sdhost: Only claim one DMA channel ) which affects most of your patch series?

> 
> thanks,
>   Gerd
>