[PATCH v4 2/7] mmc: bcm2835: Add new driver for the sdhost controller.

Gerd Hoffmann
2017-03-08T09:19:03Z

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. 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@anholt.net>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
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

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index f08691a..a638cd0 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -799,6 +799,20 @@ 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
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 6d548c4..bc2c2e2 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -59,6 +59,7 @@ 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..7d1b0db7
--- /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@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");
--
1.8.3.1