[PATCH 2/4] mmc: bcm2835: Add new driver for the internal SD controller.
Gerd Hoffmann
kraxel at redhat.com
Fri Jan 27 03:36:27 PST 2017
From: Eric Anholt <eric at anholt.net>
The 2835 has two SD controllers: The Arasan SDHCI controller (supported
by the iproc driver) and a custom SD controller. This patch adds a
driver for the custom SD controller.
The custom controller runs faster, and driving the sdcard with the
custom controller also allows to drive the rpi3 wifi with the iproc
driver.
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 at 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 at 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.
Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
---
drivers/mmc/host/Kconfig | 9 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/bcm2835.c | 1495 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1505 insertions(+)
create mode 100644 drivers/mmc/host/bcm2835.c
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 2eb9701..793adae 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -790,6 +790,15 @@ 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
+ help
+ This selects the BCM2835 SDHOST MMC controller. If you have a BCM2835
+ platform with SD or MMC devices, say Y or M here.
+
+ 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..e8a3f6e
--- /dev/null
+++ b/drivers/mmc/host/bcm2835.c
@@ -0,0 +1,1495 @@
+/*
+ * BCM2835 SD host driver.
+ *
+ * Author: Phil Elwell <phil at raspberrypi.org>
+ * Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
+ *
+ * Based on
+ * mmc-bcm2835.c by Gellert Weisz
+ * which is, in turn, based on
+ * sdhci-bcm2708.c by Broadcom
+ * sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
+ * sdhci.c and sdhci-pci.c by Pierre Ossman
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/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 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(void *param)
+{
+ struct bcm2835_host *host = param;
+ 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) {
+ void *page;
+ u32 *buf;
+
+ 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);
+ }
+
+ bcm2835_finish_data(host);
+
+ mutex_unlock(&host->mutex);
+}
+
+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 = (struct page *)sg->page_link;
+ 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;
+
+ /* Sanity checks */
+ WARN_ON(data->blksz * data->blocks > 524288);
+ WARN_ON(data->blksz > host->mmc->max_blk_size);
+ WARN_ON(data->blocks > 65535);
+
+ 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 = 0; /* Initialized for compiler warning */
+
+ /* 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.
+ */
+
+ host->mmc->actual_clock = 0;
+
+ 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_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_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
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