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Message-Id: <1456527942-3045-3-git-send-email-eric@anholt.net>
Date: Fri, 26 Feb 2016 15:05:40 -0800
From: Eric Anholt <eric@...olt.net>
To: linux-rpi-kernel@...ts.infradead.org
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
Stephen Warren <swarren@...dotorg.org>,
Lee Jones <lee@...nel.org>,
Florian Fainelli <f.fainelli@...il.com>,
Rob Herring <robh+dt@...nel.org>,
Pawel Moll <pawel.moll@....com>,
Mark Rutland <mark.rutland@....com>,
Ian Campbell <ijc+devicetree@...lion.org.uk>,
Kumar Gala <galak@...eaurora.org>, devicetree@...r.kernel.org,
Ulf Hansson <ulf.hansson@...aro.org>,
linux-mmc@...r.kernel.org, Eric Anholt <eric@...olt.net>
Subject: [PATCH 2/4] mmc: bcm2835-sdhost: Add new driver for the internal SD controller.
The 2835 has two SD controllers: The Arasan SDHCI controller that we
currently use, and a custom SD controller. The custom one runs faster
at 16.7MB/sec reads on PIO (according to hdparm -t on a Pi 2B) instead
of 10.15MB/sec, and up to 18.45MB/sec with DMA enabled.
The code was originally written by Phil Elwell in the downstream
Rasbperry Pi tree, and I did a major cleanup on it (+319, -721 lines
out of the original 2055) for inclusion.
Signed-off-by: Eric Anholt <eric@...olt.net>
---
drivers/mmc/host/Kconfig | 9 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/bcm2835-sdhost.c | 1652 +++++++++++++++++++++++++++++++++++++
3 files changed, 1662 insertions(+)
create mode 100644 drivers/mmc/host/bcm2835-sdhost.c
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1526b8a..b991a21 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -778,6 +778,15 @@ config MMC_TOSHIBA_PCI
depends on PCI
help
+config MMC_BCM2835_SDHOST
+ 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 3595f83..b31b994 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_MMC_MOXART) += moxart-mmc.o
obj-$(CONFIG_MMC_SUNXI) += sunxi-mmc.o
obj-$(CONFIG_MMC_USDHI6ROL0) += usdhi6rol0.o
obj-$(CONFIG_MMC_TOSHIBA_PCI) += toshsd.o
+obj-$(CONFIG_MMC_BCM2835_SDHOST) += bcm2835-sdhost.o
obj-$(CONFIG_MMC_REALTEK_PCI) += rtsx_pci_sdmmc.o
obj-$(CONFIG_MMC_REALTEK_USB) += rtsx_usb_sdmmc.o
diff --git a/drivers/mmc/host/bcm2835-sdhost.c b/drivers/mmc/host/bcm2835-sdhost.c
new file mode 100644
index 0000000..a84f675
--- /dev/null
+++ b/drivers/mmc/host/bcm2835-sdhost.c
@@ -0,0 +1,1652 @@
+/*
+ * BCM2835 SD host driver.
+ *
+ * Author: Phil Elwell <phil@...pberrypi.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/delay.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/sd.h>
+#include <linux/scatterlist.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/blkdev.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_dma.h>
+#include <linux/time.h>
+#include <linux/workqueue.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 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;
+
+ void __iomem *ioaddr;
+ u32 phys_addr;
+
+ struct mmc_host *mmc;
+
+ u32 pio_timeout; /* In jiffies */
+
+ int clock; /* Current clock speed */
+
+ unsigned int max_clk; /* Max possible freq */
+
+ struct tasklet_struct finish_tasklet; /* Tasklet structures */
+
+ struct work_struct cmd_wait_wq; /* Workqueue function */
+
+ struct timer_list timer; /* Timer for timeouts */
+
+ struct sg_mapping_iter sg_miter; /* SG state for PIO */
+ unsigned int blocks; /* remaining PIO blocks */
+
+ int irq; /* Device IRQ */
+
+ u32 cmd_quick_poll_retries;
+ u32 ns_per_fifo_word;
+
+ /* cached registers */
+ u32 hcfg;
+ u32 cdiv;
+
+ /* Current request */
+ struct mmc_request *mrq;
+ /* Current command */
+ struct mmc_command *cmd;
+ /* Current data request */
+ struct mmc_data *data;
+ /* Data finished before cmd */
+ bool data_complete:1;
+ /* Drain the fifo when finishing */
+ bool flush_fifo:1;
+ /* Wait for busy interrupt */
+ bool use_busy:1;
+ /* Send CMD23 */
+ bool use_sbc:1;
+
+ /*DMA part*/
+ struct dma_chan *dma_chan_rx;
+ struct dma_chan *dma_chan_tx;
+ /* Channel in use */
+ 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;
+ /*end of DMA part*/
+ /* maximum length of time spent waiting */
+ int max_delay;
+ /* Maximum block count for PIO (0 = always DMA) */
+ u32 pio_limit;
+};
+
+static inline void bcm2835_sdhost_write(struct bcm2835_host *host,
+ u32 val, int reg)
+{
+ writel(val, host->ioaddr + reg);
+}
+
+static inline u32 bcm2835_sdhost_read(struct bcm2835_host *host, int reg)
+{
+ return readl(host->ioaddr + reg);
+}
+
+static inline u32 bcm2835_sdhost_read_relaxed(struct bcm2835_host *host,
+ int reg)
+{
+ return readl_relaxed(host->ioaddr + reg);
+}
+
+static void bcm2835_sdhost_dumpcmd(struct bcm2835_host *host,
+ struct mmc_command *cmd,
+ const char *label)
+{
+ if (!cmd)
+ return;
+
+ pr_err("%s:%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n",
+ mmc_hostname(host->mmc),
+ (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_sdhost_dumpregs(struct bcm2835_host *host)
+{
+ if (host->mrq) {
+ bcm2835_sdhost_dumpcmd(host, host->mrq->sbc, "sbc");
+ bcm2835_sdhost_dumpcmd(host, host->mrq->cmd, "cmd");
+ if (host->mrq->data) {
+ pr_err("%s: data blocks %x blksz %x - err %d\n",
+ mmc_hostname(host->mmc),
+ host->mrq->data->blocks,
+ host->mrq->data->blksz,
+ host->mrq->data->error);
+ }
+ bcm2835_sdhost_dumpcmd(host, host->mrq->stop, "stop");
+ }
+
+ pr_err("%s: =========== REGISTER DUMP ===========\n",
+ mmc_hostname(host->mmc));
+
+ pr_err("%s: SDCMD 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDCMD));
+ pr_err("%s: SDARG 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDARG));
+ pr_err("%s: SDTOUT 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDTOUT));
+ pr_err("%s: SDCDIV 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDCDIV));
+ pr_err("%s: SDRSP0 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDRSP0));
+ pr_err("%s: SDRSP1 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDRSP1));
+ pr_err("%s: SDRSP2 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDRSP2));
+ pr_err("%s: SDRSP3 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDRSP3));
+ pr_err("%s: SDHSTS 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDHSTS));
+ pr_err("%s: SDVDD 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDVDD));
+ pr_err("%s: SDEDM 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDEDM));
+ pr_err("%s: SDHCFG 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDHCFG));
+ pr_err("%s: SDHBCT 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDHBCT));
+ pr_err("%s: SDHBLC 0x%08x\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDHBLC));
+
+ pr_err("%s: ===========================================\n",
+ mmc_hostname(host->mmc));
+}
+
+static void bcm2835_sdhost_set_power(struct bcm2835_host *host, bool on)
+{
+ bcm2835_sdhost_write(host, on ? 1 : 0, SDVDD);
+}
+
+static void bcm2835_sdhost_reset_internal(struct bcm2835_host *host)
+{
+ u32 temp;
+
+ bcm2835_sdhost_set_power(host, false);
+
+ bcm2835_sdhost_write(host, 0, SDCMD);
+ bcm2835_sdhost_write(host, 0, SDARG);
+ bcm2835_sdhost_write(host, 0xf00000, SDTOUT);
+ bcm2835_sdhost_write(host, 0, SDCDIV);
+ bcm2835_sdhost_write(host, 0x7f8, SDHSTS); /* Write 1s to clear */
+ bcm2835_sdhost_write(host, 0, SDHCFG);
+ bcm2835_sdhost_write(host, 0, SDHBCT);
+ bcm2835_sdhost_write(host, 0, SDHBLC);
+
+ /* Limit fifo usage due to silicon bug */
+ temp = bcm2835_sdhost_read(host, 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);
+ bcm2835_sdhost_write(host, temp, SDEDM);
+ mdelay(10);
+ bcm2835_sdhost_set_power(host, true);
+ mdelay(10);
+ host->clock = 0;
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+ bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
+}
+
+static void bcm2835_sdhost_reset(struct mmc_host *mmc)
+{
+ struct bcm2835_host *host = mmc_priv(mmc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+ bcm2835_sdhost_reset_internal(host);
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
+
+static void bcm2835_sdhost_init(struct bcm2835_host *host, int soft)
+{
+ pr_debug("bcm2835_sdhost_init(%d)\n", soft);
+
+ /* Set interrupt enables */
+ host->hcfg = SDHCFG_BUSY_IRPT_EN;
+
+ bcm2835_sdhost_reset_internal(host);
+
+ if (soft) {
+ /* force clock reconfiguration */
+ host->clock = 0;
+ bcm2835_sdhost_set_ios(host->mmc, &host->mmc->ios);
+ }
+}
+
+static void bcm2835_sdhost_wait_transfer_complete(struct bcm2835_host *host)
+{
+ int timediff;
+ u32 alternate_idle;
+ u32 edm;
+
+ alternate_idle = (host->mrq->data->flags & MMC_DATA_READ) ?
+ SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
+
+ edm = bcm2835_sdhost_read(host, SDEDM);
+
+ timediff = 0;
+
+ while (1) {
+ u32 fsm = edm & SDEDM_FSM_MASK;
+
+ if ((fsm == SDEDM_FSM_IDENTMODE) ||
+ (fsm == SDEDM_FSM_DATAMODE))
+ break;
+ if (fsm == alternate_idle) {
+ bcm2835_sdhost_write(host,
+ edm | SDEDM_FORCE_DATA_MODE,
+ SDEDM);
+ break;
+ }
+
+ timediff++;
+ if (timediff == 100000) {
+ pr_err("%s: wait_transfer_complete - still waiting after %d retries\n",
+ mmc_hostname(host->mmc),
+ timediff);
+ bcm2835_sdhost_dumpregs(host);
+ host->mrq->data->error = -ETIMEDOUT;
+ return;
+ }
+ cpu_relax();
+ edm = bcm2835_sdhost_read(host, SDEDM);
+ }
+}
+
+static void bcm2835_sdhost_finish_data(struct bcm2835_host *host);
+
+static void bcm2835_sdhost_dma_complete(void *param)
+{
+ struct bcm2835_host *host = param;
+ struct mmc_data *data = host->data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ 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 = bcm2835_sdhost_read(host, SDEDM);
+
+ if ((edm >> 4) & 0x1f)
+ *(buf++) = bcm2835_sdhost_read(host,
+ SDDATA);
+ host->drain_words--;
+ }
+
+ kunmap_atomic(page);
+ }
+
+ bcm2835_sdhost_finish_data(host);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_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 = bcm2835_sdhost_read(host, 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);
+
+ 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 = bcm2835_sdhost_read(host,
+ SDHSTS);
+ pr_err("%s: fsm %x, hsts %x\n",
+ mmc_hostname(host->mmc),
+ fsm_state, hsts);
+ if (hsts & SDHSTS_ERROR_MASK)
+ break;
+ }
+
+ if (time_after(jiffies, wait_max)) {
+ pr_err("%s: PIO %s timeout - EDM %x\n",
+ is_read ? "read" : "write",
+ mmc_hostname(host->mmc),
+ 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++) = bcm2835_sdhost_read(host,
+ SDDATA);
+ } else {
+ bcm2835_sdhost_write(host, *(buf++),
+ SDDATA);
+ }
+ words--;
+ }
+ }
+
+ if (hsts & SDHSTS_ERROR_MASK)
+ break;
+ }
+
+ sg_miter_stop(&host->sg_miter);
+
+ local_irq_restore(flags);
+}
+
+static void bcm2835_sdhost_transfer_pio(struct bcm2835_host *host)
+{
+ u32 sdhsts;
+ bool is_read;
+
+ is_read = (host->data->flags & MMC_DATA_READ) != 0;
+ bcm2835_sdhost_transfer_block_pio(host, is_read);
+
+ sdhsts = bcm2835_sdhost_read(host, SDHSTS);
+ if (sdhsts & (SDHSTS_CRC16_ERROR |
+ SDHSTS_CRC7_ERROR |
+ SDHSTS_FIFO_ERROR)) {
+ pr_err("%s: %s transfer error - HSTS %x\n",
+ mmc_hostname(host->mmc),
+ is_read ? "read" : "write",
+ sdhsts);
+ host->data->error = -EILSEQ;
+ } else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
+ SDHSTS_REW_TIME_OUT))) {
+ pr_err("%s: %s timeout error - HSTS %x\n",
+ mmc_hostname(host->mmc),
+ is_read ? "read" : "write",
+ sdhsts);
+ host->data->error = -ETIMEDOUT;
+ }
+}
+
+static void bcm2835_sdhost_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;
+
+ pr_debug("bcm2835_sdhost_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_sdhost_dma_complete;
+ desc->callback_param = host;
+ host->dma_desc = desc;
+ host->dma_chan = dma_chan;
+ host->dma_dir = dir_data;
+ }
+}
+
+static void bcm2835_sdhost_start_dma(struct bcm2835_host *host)
+{
+ dmaengine_submit(host->dma_desc);
+ dma_async_issue_pending(host->dma_chan);
+}
+
+static void bcm2835_sdhost_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;
+ }
+
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+}
+
+static void bcm2835_sdhost_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_sdhost_set_transfer_irqs(host);
+
+ bcm2835_sdhost_write(host, data->blksz, SDHBCT);
+ bcm2835_sdhost_write(host, data->blocks, SDHBLC);
+}
+
+bool bcm2835_sdhost_send_command(struct bcm2835_host *host,
+ struct mmc_command *cmd)
+{
+ u32 sdcmd, sdhsts;
+ unsigned long timeout;
+ int delay;
+
+ WARN_ON(host->cmd);
+
+ if (cmd->data) {
+ pr_debug("%s: send_command %d 0x%x (flags 0x%x) - %s %d*%d\n",
+ mmc_hostname(host->mmc),
+ cmd->opcode, cmd->arg, cmd->flags,
+ (cmd->data->flags & MMC_DATA_READ) ?
+ "read" : "write", cmd->data->blocks,
+ cmd->data->blksz);
+ } else {
+ pr_debug("%s: send_command %d 0x%x (flags 0x%x)\n",
+ mmc_hostname(host->mmc),
+ cmd->opcode, cmd->arg, cmd->flags);
+ }
+
+ /* Wait max 100 ms */
+ timeout = 10000;
+
+ while (bcm2835_sdhost_read(host, SDCMD) & SDCMD_NEW_FLAG) {
+ if (timeout == 0) {
+ pr_err("%s: previous command never completed.\n",
+ mmc_hostname(host->mmc));
+ bcm2835_sdhost_dumpregs(host);
+ cmd->error = -EILSEQ;
+ tasklet_schedule(&host->finish_tasklet);
+ return false;
+ }
+ timeout--;
+ udelay(10);
+ }
+
+ delay = (10000 - timeout) / 100;
+ if (delay > host->max_delay) {
+ host->max_delay = delay;
+ pr_warn("%s: controller hung for %d ms\n",
+ mmc_hostname(host->mmc),
+ host->max_delay);
+ }
+
+ timeout = jiffies;
+ if (!cmd->data && cmd->busy_timeout > 9000)
+ timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
+ else
+ timeout += 10 * HZ;
+ mod_timer(&host->timer, timeout);
+
+ host->cmd = cmd;
+
+ /* Clear any error flags */
+ sdhsts = bcm2835_sdhost_read(host, SDHSTS);
+ if (sdhsts & SDHSTS_ERROR_MASK)
+ bcm2835_sdhost_write(host, sdhsts, SDHSTS);
+
+ if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
+ pr_err("%s: unsupported response type!\n",
+ mmc_hostname(host->mmc));
+ cmd->error = -EINVAL;
+ tasklet_schedule(&host->finish_tasklet);
+ return false;
+ }
+
+ bcm2835_sdhost_prepare_data(host, cmd);
+
+ bcm2835_sdhost_write(host, cmd->arg, 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;
+ }
+
+ bcm2835_sdhost_write(host, sdcmd | SDCMD_NEW_FLAG, SDCMD);
+
+ return true;
+}
+
+static void bcm2835_sdhost_finish_command(struct bcm2835_host *host,
+ unsigned long *irq_flags);
+
+static void bcm2835_sdhost_transfer_complete(struct bcm2835_host *host)
+{
+ struct mmc_data *data;
+
+ WARN_ON(!host->data_complete);
+
+ data = host->data;
+ host->data = NULL;
+
+ pr_debug("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_sdhost_send_command(host, host->mrq->stop)) {
+ /* No busy, so poll for completion */
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host, NULL);
+ }
+ } else {
+ bcm2835_sdhost_wait_transfer_complete(host);
+ tasklet_schedule(&host->finish_tasklet);
+ }
+}
+
+static void bcm2835_sdhost_finish_data(struct bcm2835_host *host)
+{
+ struct mmc_data *data;
+
+ data = host->data;
+
+ pr_debug("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);
+ bcm2835_sdhost_write(host, host->hcfg, 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.
+ */
+ pr_debug("Finished early - HSTS %x\n",
+ bcm2835_sdhost_read(host, SDHSTS));
+ } else {
+ bcm2835_sdhost_transfer_complete(host);
+ }
+}
+
+/* If irq_flags is valid, the caller is in a thread context and is
+ * allowed to sleep
+ */
+static void bcm2835_sdhost_finish_command(struct bcm2835_host *host,
+ unsigned long *irq_flags)
+{
+ u32 sdcmd;
+ u32 retries;
+
+ pr_debug("finish_command(%x)\n", bcm2835_sdhost_read(host, SDCMD));
+
+ /* Poll quickly at first */
+
+ retries = host->cmd_quick_poll_retries;
+ if (!retries) {
+ /* Work out how many polls take 1us by timing 10us */
+ struct timeval start, now;
+ int us_diff;
+
+ retries = 1;
+ do {
+ int i;
+
+ retries *= 2;
+
+ do_gettimeofday(&start);
+
+ for (i = 0; i < retries; i++) {
+ cpu_relax();
+ sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ }
+
+ do_gettimeofday(&now);
+ us_diff = (now.tv_sec - start.tv_sec) * 1000000 +
+ (now.tv_usec - start.tv_usec);
+ } while (us_diff < 10);
+
+ host->cmd_quick_poll_retries =
+ ((retries * us_diff + 9) * CMD_DALLY_US) / 10 + 1;
+ retries = 1; /* We've already waited long enough this time */
+ }
+
+ retries = host->cmd_quick_poll_retries;
+ for (sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ (sdcmd & SDCMD_NEW_FLAG) && !(sdcmd & SDCMD_FAIL_FLAG) && retries;
+ retries--) {
+ cpu_relax();
+ sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ }
+
+ if (!retries) {
+ unsigned long wait_max;
+
+ if (!irq_flags) {
+ /* Schedule the work */
+ schedule_work(&host->cmd_wait_wq);
+ return;
+ }
+
+ /* Wait max 100 ms */
+ wait_max = jiffies + msecs_to_jiffies(100);
+ while (time_before(jiffies, wait_max)) {
+ spin_unlock_irqrestore(&host->lock, *irq_flags);
+ usleep_range(1, 10);
+ spin_lock_irqsave(&host->lock, *irq_flags);
+ sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ if (!(sdcmd & SDCMD_NEW_FLAG) ||
+ (sdcmd & SDCMD_FAIL_FLAG))
+ break;
+ }
+ }
+
+ /* Check for errors */
+ if (sdcmd & SDCMD_NEW_FLAG) {
+ pr_err("%s: command never completed.\n",
+ mmc_hostname(host->mmc));
+ bcm2835_sdhost_dumpregs(host);
+ host->cmd->error = -EIO;
+ tasklet_schedule(&host->finish_tasklet);
+ return;
+ } else if (sdcmd & SDCMD_FAIL_FLAG) {
+ u32 sdhsts = bcm2835_sdhost_read(host, SDHSTS);
+
+ /* Clear the errors */
+ bcm2835_sdhost_write(host, SDHSTS_ERROR_MASK, SDHSTS);
+
+ if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
+ (host->cmd->opcode != 1)) {
+ if (sdhsts & SDHSTS_CMD_TIME_OUT) {
+ host->cmd->error = -ETIMEDOUT;
+ } else {
+ pr_err("%s: unexpected command %d error\n",
+ mmc_hostname(host->mmc),
+ host->cmd->opcode);
+ bcm2835_sdhost_dumpregs(host);
+ host->cmd->error = -EILSEQ;
+ }
+ tasklet_schedule(&host->finish_tasklet);
+ return;
+ }
+ }
+
+ if (host->cmd->flags & MMC_RSP_PRESENT) {
+ if (host->cmd->flags & MMC_RSP_136) {
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ host->cmd->resp[3 - i] =
+ bcm2835_sdhost_read(host,
+ SDRSP0 + i * 4);
+ }
+
+ pr_debug("%s: finish_command %08x %08x %08x %08x\n",
+ mmc_hostname(host->mmc),
+ host->cmd->resp[0], host->cmd->resp[1],
+ host->cmd->resp[2], host->cmd->resp[3]);
+ } else {
+ host->cmd->resp[0] = bcm2835_sdhost_read(host, SDRSP0);
+ pr_debug("%s: finish_command %08x\n",
+ mmc_hostname(host->mmc),
+ host->cmd->resp[0]);
+ }
+ }
+
+ if (host->cmd == host->mrq->sbc) {
+ /* Finished CMD23, now send actual command. */
+ host->cmd = NULL;
+ if (bcm2835_sdhost_send_command(host, host->mrq->cmd)) {
+ if (host->data && host->dma_desc)
+ /* DMA transfer starts now, PIO starts
+ * after irq
+ */
+ bcm2835_sdhost_start_dma(host);
+
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host, NULL);
+ }
+ } else if (host->cmd == host->mrq->stop) {
+ /* Finished CMD12 */
+ tasklet_schedule(&host->finish_tasklet);
+ } else {
+ /* Processed actual command. */
+ host->cmd = NULL;
+ if (!host->data)
+ tasklet_schedule(&host->finish_tasklet);
+ else if (host->data_complete)
+ bcm2835_sdhost_transfer_complete(host);
+ }
+}
+
+static void bcm2835_sdhost_timeout(unsigned long data)
+{
+ struct bcm2835_host *host;
+ unsigned long flags;
+
+ host = (struct bcm2835_host *)data;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ if (host->mrq) {
+ pr_err("%s: timeout waiting for hardware interrupt.\n",
+ mmc_hostname(host->mmc));
+ bcm2835_sdhost_dumpregs(host);
+
+ if (host->data) {
+ host->data->error = -ETIMEDOUT;
+ bcm2835_sdhost_finish_data(host);
+ } else {
+ if (host->cmd)
+ host->cmd->error = -ETIMEDOUT;
+ else
+ host->mrq->cmd->error = -ETIMEDOUT;
+
+ pr_debug("timeout_timer tasklet_schedule\n");
+ tasklet_schedule(&host->finish_tasklet);
+ }
+ }
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_busy_irq(struct bcm2835_host *host, u32 intmask)
+{
+ if (!host->cmd) {
+ pr_err("%s: got command busy interrupt 0x%08x even though no command operation was in progress.\n",
+ mmc_hostname(host->mmc), (unsigned)intmask);
+ bcm2835_sdhost_dumpregs(host);
+ return;
+ }
+
+ if (!host->use_busy) {
+ pr_err("%s: got command busy interrupt 0x%08x even though not expecting one.\n",
+ mmc_hostname(host->mmc), (unsigned)intmask);
+ bcm2835_sdhost_dumpregs(host);
+ return;
+ }
+ host->use_busy = false;
+
+ if (intmask & SDHSTS_ERROR_MASK) {
+ pr_err("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_sdhost_dumpregs(host);
+ } else {
+ bcm2835_sdhost_finish_command(host, NULL);
+ }
+}
+
+static void bcm2835_sdhost_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;
+
+ if (intmask & (SDHSTS_CRC16_ERROR |
+ SDHSTS_FIFO_ERROR |
+ SDHSTS_REW_TIME_OUT)) {
+ if (intmask & (SDHSTS_CRC16_ERROR |
+ SDHSTS_FIFO_ERROR))
+ host->data->error = -EILSEQ;
+ else
+ host->data->error = -ETIMEDOUT;
+ }
+
+ if (host->data->error) {
+ bcm2835_sdhost_finish_data(host);
+ } else 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;
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+ bcm2835_sdhost_transfer_pio(host);
+ } else {
+ bcm2835_sdhost_transfer_pio(host);
+ host->blocks--;
+ if ((host->blocks == 0) || host->data->error)
+ bcm2835_sdhost_finish_data(host);
+ }
+}
+
+static void bcm2835_sdhost_block_irq(struct bcm2835_host *host, u32 intmask)
+{
+ if (!host->data) {
+ pr_err("%s: got block interrupt 0x%08x even though no data operation was in progress.\n",
+ mmc_hostname(host->mmc), (unsigned)intmask);
+ bcm2835_sdhost_dumpregs(host);
+ return;
+ }
+
+ if (intmask & (SDHSTS_CRC16_ERROR |
+ SDHSTS_FIFO_ERROR |
+ SDHSTS_REW_TIME_OUT)) {
+ if (intmask & (SDHSTS_CRC16_ERROR |
+ SDHSTS_FIFO_ERROR))
+ host->data->error = -EILSEQ;
+ else
+ host->data->error = -ETIMEDOUT;
+ }
+
+ if (!host->dma_desc) {
+ WARN_ON(!host->blocks);
+ if (host->data->error || (--host->blocks == 0))
+ bcm2835_sdhost_finish_data(host);
+ else
+ bcm2835_sdhost_transfer_pio(host);
+ } else if (host->data->flags & MMC_DATA_WRITE) {
+ bcm2835_sdhost_finish_data(host);
+ }
+}
+
+static irqreturn_t bcm2835_sdhost_irq(int irq, void *dev_id)
+{
+ irqreturn_t result = IRQ_NONE;
+ struct bcm2835_host *host = dev_id;
+ u32 intmask;
+
+ spin_lock(&host->lock);
+
+ intmask = bcm2835_sdhost_read(host, SDHSTS);
+
+ bcm2835_sdhost_write(host,
+ SDHSTS_BUSY_IRPT |
+ SDHSTS_BLOCK_IRPT |
+ SDHSTS_SDIO_IRPT |
+ SDHSTS_DATA_FLAG,
+ SDHSTS);
+
+ if (intmask & SDHSTS_BLOCK_IRPT) {
+ bcm2835_sdhost_block_irq(host, intmask);
+ result = IRQ_HANDLED;
+ }
+
+ if (intmask & SDHSTS_BUSY_IRPT) {
+ bcm2835_sdhost_busy_irq(host, intmask);
+ 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_sdhost_data_irq(host, intmask);
+ result = IRQ_HANDLED;
+ }
+
+ spin_unlock(&host->lock);
+
+ return result;
+}
+
+void bcm2835_sdhost_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;
+ bcm2835_sdhost_write(host, host->cdiv, 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;
+ bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
+
+ /* Set the timeout to 500ms */
+ bcm2835_sdhost_write(host, host->mmc->actual_clock / 2, SDTOUT);
+}
+
+static void bcm2835_sdhost_request(struct mmc_host *mmc,
+ struct mmc_request *mrq)
+{
+ struct bcm2835_host *host;
+ unsigned long flags;
+ u32 edm, fsm;
+
+ host = mmc_priv(mmc);
+
+ /* 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)) {
+ pr_err("%s: unsupported block size (%d bytes)\n",
+ mmc_hostname(mmc), 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_sdhost_prepare_dma(host, mrq->data);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ WARN_ON(host->mrq);
+ host->mrq = mrq;
+
+ edm = bcm2835_sdhost_read(host, SDEDM);
+ fsm = edm & SDEDM_FSM_MASK;
+
+ if ((fsm != SDEDM_FSM_IDENTMODE) &&
+ (fsm != SDEDM_FSM_DATAMODE)) {
+ pr_err("%s: previous command (%d) not complete (EDM %x)\n",
+ mmc_hostname(host->mmc),
+ bcm2835_sdhost_read(host, SDCMD) & SDCMD_CMD_MASK,
+ edm);
+ bcm2835_sdhost_dumpregs(host);
+ mrq->cmd->error = -EILSEQ;
+ tasklet_schedule(&host->finish_tasklet);
+ spin_unlock_irqrestore(&host->lock, flags);
+ return;
+ }
+
+ host->use_sbc = !!mrq->sbc && (host->mrq->data->flags & MMC_DATA_READ);
+ if (host->use_sbc) {
+ if (bcm2835_sdhost_send_command(host, mrq->sbc)) {
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host, &flags);
+ }
+ } else if (bcm2835_sdhost_send_command(host, mrq->cmd)) {
+ if (host->data && host->dma_desc) {
+ /* DMA transfer starts now, PIO starts after irq */
+ bcm2835_sdhost_start_dma(host);
+ }
+
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host, &flags);
+ }
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+ struct bcm2835_host *host = mmc_priv(mmc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ if (!ios->clock || ios->clock != host->clock) {
+ bcm2835_sdhost_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;
+
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static struct mmc_host_ops bcm2835_sdhost_ops = {
+ .request = bcm2835_sdhost_request,
+ .set_ios = bcm2835_sdhost_set_ios,
+ .hw_reset = bcm2835_sdhost_reset,
+};
+
+static void bcm2835_sdhost_cmd_wait_work(struct work_struct *work)
+{
+ struct bcm2835_host *host;
+ unsigned long flags;
+
+ host = container_of(work, struct bcm2835_host, cmd_wait_wq);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ /* If this tasklet gets rescheduled while running, it will
+ * be run again afterwards but without any active request.
+ */
+ if (!host->mrq) {
+ spin_unlock_irqrestore(&host->lock, flags);
+ return;
+ }
+
+ bcm2835_sdhost_finish_command(host, &flags);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_tasklet_finish(unsigned long param)
+{
+ struct bcm2835_host *host;
+ unsigned long flags;
+ struct mmc_request *mrq;
+ struct dma_chan *terminate_chan = NULL;
+
+ host = (struct bcm2835_host *)param;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ /* If this tasklet gets rescheduled while running, it will
+ * be run again afterwards but without any active request.
+ */
+ if (!host->mrq) {
+ spin_unlock_irqrestore(&host->lock, flags);
+ return;
+ }
+
+ del_timer(&host->timer);
+
+ 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;
+
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ if (terminate_chan) {
+ int err = dmaengine_terminate_all(terminate_chan);
+
+ if (err)
+ pr_err("%s: failed to terminate DMA (%d)\n",
+ mmc_hostname(host->mmc), err);
+ }
+
+ mmc_request_done(host->mmc, mrq);
+}
+
+int bcm2835_sdhost_add_host(struct bcm2835_host *host)
+{
+ struct mmc_host *mmc;
+ struct dma_slave_config cfg;
+ char pio_limit_string[20];
+ int ret;
+
+ mmc = host->mmc;
+
+ bcm2835_sdhost_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);
+
+ pr_debug("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);
+
+ if (IS_ERR_OR_NULL(host->dma_chan_tx) ||
+ IS_ERR_OR_NULL(host->dma_chan_rx)) {
+ pr_err("%s: unable to initialise DMA channels. Falling back to PIO\n",
+ mmc_hostname(mmc));
+ 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;
+
+ tasklet_init(&host->finish_tasklet,
+ bcm2835_sdhost_tasklet_finish, (unsigned long)host);
+
+ INIT_WORK(&host->cmd_wait_wq, bcm2835_sdhost_cmd_wait_work);
+
+ setup_timer(&host->timer, bcm2835_sdhost_timeout,
+ (unsigned long)host);
+
+ bcm2835_sdhost_init(host, 0);
+
+ ret = request_irq(host->irq, bcm2835_sdhost_irq, 0 /*IRQF_SHARED*/,
+ mmc_hostname(mmc), host);
+ if (ret) {
+ pr_err("%s: failed to request IRQ %d: %d\n",
+ mmc_hostname(mmc), host->irq, ret);
+ goto untasklet;
+ }
+
+ 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);
+ pr_info("%s: loaded - DMA %s%s\n",
+ mmc_hostname(mmc),
+ host->use_dma ? "enabled" : "disabled",
+ pio_limit_string);
+
+ return 0;
+
+untasklet:
+ tasklet_kill(&host->finish_tasklet);
+
+ return ret;
+}
+
+static int bcm2835_sdhost_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct clk *clk;
+ struct resource *iomem;
+ struct bcm2835_host *host;
+ struct mmc_host *mmc;
+ int ret;
+
+ pr_debug("bcm2835_sdhost_probe\n");
+ mmc = mmc_alloc_host(sizeof(*host), dev);
+ if (!mmc)
+ return -ENOMEM;
+
+ mmc->ops = &bcm2835_sdhost_ops;
+ host = mmc_priv(mmc);
+ host->mmc = mmc;
+ host->cmd_quick_poll_retries = 0;
+ 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.
+ */
+ host->phys_addr = be32_to_cpup(of_get_address(pdev->dev.of_node, 0,
+ NULL, NULL));
+
+ pr_debug(" - 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;
+ }
+
+ pr_debug(" - max_clk %lx, irq %d\n",
+ (unsigned long)host->max_clk,
+ (int)host->irq);
+
+ mmc_of_parse(mmc);
+
+ ret = bcm2835_sdhost_add_host(host);
+ if (ret)
+ goto err;
+
+ platform_set_drvdata(pdev, host);
+
+ pr_debug("bcm2835_sdhost_probe -> OK\n");
+
+ return 0;
+
+err:
+ pr_debug("bcm2835_sdhost_probe -> err %d\n", ret);
+ mmc_free_host(mmc);
+
+ return ret;
+}
+
+static int bcm2835_sdhost_remove(struct platform_device *pdev)
+{
+ struct bcm2835_host *host = platform_get_drvdata(pdev);
+
+ pr_debug("bcm2835_sdhost_remove\n");
+
+ mmc_remove_host(host->mmc);
+
+ bcm2835_sdhost_set_power(host, false);
+
+ free_irq(host->irq, host);
+
+ del_timer_sync(&host->timer);
+
+ tasklet_kill(&host->finish_tasklet);
+
+ mmc_free_host(host->mmc);
+ platform_set_drvdata(pdev, NULL);
+
+ pr_debug("bcm2835_sdhost_remove - OK\n");
+ return 0;
+}
+
+static const struct of_device_id bcm2835_sdhost_match[] = {
+ { .compatible = "brcm,bcm2835-sdhost" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, bcm2835_sdhost_match);
+
+static struct platform_driver bcm2835_sdhost_driver = {
+ .probe = bcm2835_sdhost_probe,
+ .remove = bcm2835_sdhost_remove,
+ .driver = {
+ .name = "sdhost-bcm2835",
+ .of_match_table = bcm2835_sdhost_match,
+ },
+};
+module_platform_driver(bcm2835_sdhost_driver);
+
+MODULE_ALIAS("platform:sdhost-bcm2835");
+MODULE_DESCRIPTION("BCM2835 SDHost driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Phil Elwell");
--
2.7.0
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