From 74c824df73fca559e8d4114051f66eab362b441e Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Wed, 25 Mar 2015 17:49:47 +0000
Subject: [PATCH 009/222] Adding bcm2835-sdhost driver, and an overlay to
enable it
BCM2835 has two SD card interfaces. This driver uses the other one.
bcm2835-sdhost: Error handling fix, and code clarification
bcm2835-sdhost: Adding overclocking option
Allow a different clock speed to be substitued for a requested 50MHz.
This option is exposed using the "overclock_50" DT parameter.
Note that the sdhost interface is restricted to integer divisions of
core_freq, and the highest sensible option for a core_freq of 250MHz
is 84 (250/3 = 83.3MHz), the next being 125 (250/2) which is much too
high.
Use at your own risk.
bcm2835-sdhost: Round up the overclock, so 62 works for 62.5Mhz
Also only warn once for each overclock setting.
---
drivers/mmc/host/Kconfig | 10 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/bcm2835-sdhost.c | 1702 +++++++++++++++++++++++++++++++++++++
3 files changed, 1713 insertions(+)
create mode 100644 drivers/mmc/host/bcm2835-sdhost.c
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -33,6 +33,16 @@ config MMC_BCM2835_PIO_DMA_BARRIER
If unsure, say 2 here.
+config MMC_BCM2835_SDHOST
+ tristate "Support for the SDHost controller on BCM2708/9"
+ depends on MACH_BCM2708 || MACH_BCM2709 || ARCH_BCM2835
+ help
+ This selects the SDHost controller on BCM2835/6.
+
+ If you have a controller with this interface, say Y or M here.
+
+ If unsure, say N.
+
config MMC_ARMMMCI
tristate "ARM AMBA Multimedia Card Interface support"
depends on ARM_AMBA
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_MMC_SDHCI_S3C) += sdhci-s3c
obj-$(CONFIG_MMC_SDHCI_SIRF) += sdhci-sirf.o
obj-$(CONFIG_MMC_SDHCI_F_SDH30) += sdhci_f_sdh30.o
obj-$(CONFIG_MMC_SDHCI_SPEAR) += sdhci-spear.o
+obj-$(CONFIG_MMC_BCM2835_SDHOST) += bcm2835-sdhost.o
obj-$(CONFIG_MMC_BCM2835) += bcm2835-mmc.o
obj-$(CONFIG_MMC_WBSD) += wbsd.o
obj-$(CONFIG_MMC_AU1X) += au1xmmc.o
--- /dev/null
+++ b/drivers/mmc/host/bcm2835-sdhost.c
@@ -0,0 +1,1702 @@
+/*
+ * BCM2835 SD host driver.
+ *
+ * Author: Phil Elwell <phil@raspberrypi.org>
+ * Copyright 2015
+ *
+ * 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/>.
+ */
+
+#define SAFE_READ_THRESHOLD 4
+#define SAFE_WRITE_THRESHOLD 4
+#define ALLOW_DMA 1
+#define ALLOW_CMD23 0
+#define ALLOW_FAST 1
+#define USE_BLOCK_IRQ 1
+
+#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>
+
+#define DRIVER_NAME "sdhost-bcm2835"
+
+#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_CRC16_ERROR|SDHSTS_REW_TIME_OUT|SDHSTS_FIFO_ERROR)
+#define SDHSTS_ERROR_MASK (SDHSTS_CMD_TIME_OUT|SDHSTS_TRANSFER_ERROR_MASK)
+/* SDHSTS_CRC7_ERROR - ignore this as MMC cards generate this spuriously */
+
+#define SDHCFG_BUSY_IRPT_EN (1<<10)
+#define SDHCFG_BLOCK_IRPT_EN (1<<8)
+#define SDHCFG_SDIO_IRPT_EN (1<<5)
+#define SDHCFG_DATA_IRPT_EN (1<<4)
+#define SDHCFG_SLOW_CARD (1<<3)
+#define SDHCFG_WIDE_EXT_BUS (1<<2)
+#define SDHCFG_WIDE_INT_BUS (1<<1)
+#define SDHCFG_REL_CMD_LINE (1<<0)
+
+#define SDEDM_FORCE_DATA_MODE (1<<19)
+#define SDEDM_CLOCK_PULSE (1<<20)
+#define SDEDM_BYPASS (1<<21)
+
+#define SDEDM_WRITE_THRESHOLD_SHIFT 9
+#define SDEDM_READ_THRESHOLD_SHIFT 14
+#define SDEDM_THRESHOLD_MASK 0x1f
+
+/* the inclusive limit in bytes under which PIO will be used instead of DMA */
+#ifdef CONFIG_MMC_BCM2835_SDHOST_PIO_DMA_BARRIER
+#define PIO_DMA_BARRIER CONFIG_MMC_BCM2835_SDHOST_PIO_DMA_BARRIER
+#else
+#define PIO_DMA_BARRIER 0
+#endif
+
+#define MIN_FREQ 400000
+#define TIMEOUT_VAL 0xE
+#define BCM2835_SDHOST_WRITE_DELAY(f) (((2 * 1000000) / f) + 1)
+
+#ifndef BCM2708_PERI_BASE
+ #define BCM2708_PERI_BASE 0x20000000
+#endif
+
+/* FIXME: Needs IOMMU support */
+#define BCM2835_VCMMU_SHIFT (0x7E000000 - BCM2708_PERI_BASE)
+
+
+struct bcm2835_host {
+ spinlock_t lock;
+
+ void __iomem *ioaddr;
+ u32 phys_addr;
+
+ struct mmc_host *mmc;
+
+ u32 timeout;
+
+ int clock; /* Current clock speed */
+
+ bool slow_card; /* Force 11-bit divisor */
+
+ unsigned int max_clk; /* Max possible freq */
+ unsigned int timeout_clk; /* Timeout freq (KHz) */
+
+ struct tasklet_struct finish_tasklet; /* Tasklet structures */
+
+ 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 */
+
+
+ /* 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 */
+ unsigned int data_complete:1; /* Data finished before cmd */
+
+ unsigned int flush_fifo:1; /* Drain the fifo when finishing */
+
+ unsigned int use_busy:1; /* Wait for busy interrupt */
+
+ u32 thread_isr;
+
+ /*DMA part*/
+ struct dma_chan *dma_chan_rx; /* DMA channel for reads */
+ struct dma_chan *dma_chan_tx; /* DMA channel for writes */
+
+ bool allow_dma;
+ bool have_dma;
+ bool use_dma;
+ /*end of DMA part*/
+
+ int max_delay; /* maximum length of time spent waiting */
+ struct timeval stop_time; /* when the last stop was issued */
+ u32 delay_after_stop; /* minimum time between stop and subsequent data transfer */
+ u32 overclock_50; /* frequency to use when 50MHz is requested (in MHz) */
+ u32 max_overclock; /* Highest reported */
+};
+
+
+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_dumpregs(struct bcm2835_host *host)
+{
+ pr_info(DRIVER_NAME ": =========== REGISTER DUMP (%s)===========\n",
+ mmc_hostname(host->mmc));
+
+ pr_info(DRIVER_NAME ": SDCMD 0x%08x\n",
+ bcm2835_sdhost_read(host, SDCMD));
+ pr_info(DRIVER_NAME ": SDARG 0x%08x\n",
+ bcm2835_sdhost_read(host, SDARG));
+ pr_info(DRIVER_NAME ": SDTOUT 0x%08x\n",
+ bcm2835_sdhost_read(host, SDTOUT));
+ pr_info(DRIVER_NAME ": SDCDIV 0x%08x\n",
+ bcm2835_sdhost_read(host, SDCDIV));
+ pr_info(DRIVER_NAME ": SDRSP0 0x%08x\n",
+ bcm2835_sdhost_read(host, SDRSP0));
+ pr_info(DRIVER_NAME ": SDRSP1 0x%08x\n",
+ bcm2835_sdhost_read(host, SDRSP1));
+ pr_info(DRIVER_NAME ": SDRSP2 0x%08x\n",
+ bcm2835_sdhost_read(host, SDRSP2));
+ pr_info(DRIVER_NAME ": SDRSP3 0x%08x\n",
+ bcm2835_sdhost_read(host, SDRSP3));
+ pr_info(DRIVER_NAME ": SDHSTS 0x%08x\n",
+ bcm2835_sdhost_read(host, SDHSTS));
+ pr_info(DRIVER_NAME ": SDVDD 0x%08x\n",
+ bcm2835_sdhost_read(host, SDVDD));
+ pr_info(DRIVER_NAME ": SDEDM 0x%08x\n",
+ bcm2835_sdhost_read(host, SDEDM));
+ pr_info(DRIVER_NAME ": SDHCFG 0x%08x\n",
+ bcm2835_sdhost_read(host, SDHCFG));
+ pr_info(DRIVER_NAME ": SDHBCT 0x%08x\n",
+ bcm2835_sdhost_read(host, SDHBCT));
+ pr_info(DRIVER_NAME ": SDHBLC 0x%08x\n",
+ bcm2835_sdhost_read(host, SDHBLC));
+
+ pr_debug(DRIVER_NAME ": ===========================================\n");
+}
+
+
+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(struct bcm2835_host *host)
+{
+ u32 temp;
+
+ pr_debug("bcm2835_sdhost_reset\n");
+
+ 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 |= (SAFE_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
+ (SAFE_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);
+ mmiowb();
+}
+
+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(host);
+
+ if (soft) {
+ /* force clock reconfiguration */
+ host->clock = 0;
+ bcm2835_sdhost_set_ios(host->mmc, &host->mmc->ios);
+ }
+}
+
+static bool bcm2835_sdhost_is_write_complete(struct bcm2835_host *host)
+{
+ bool write_complete = ((bcm2835_sdhost_read(host, SDEDM) & 0xf) == 1);
+
+ if (!write_complete) {
+ /* Request an IRQ for the last block */
+ host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+ if ((bcm2835_sdhost_read(host, SDEDM) & 0xf) == 1) {
+ /* The write has now completed. Disable the interrupt
+ and clear the status flag */
+ host->hcfg &= ~SDHCFG_BLOCK_IRPT_EN;
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+ bcm2835_sdhost_write(host, SDHSTS_BLOCK_IRPT, SDHSTS);
+ write_complete = true;
+ }
+ }
+
+ return write_complete;
+}
+
+static void bcm2835_sdhost_wait_write_complete(struct bcm2835_host *host)
+{
+ int timediff;
+#ifdef DEBUG
+ static struct timeval start_time;
+ static int max_stall_time = 0;
+ static int total_stall_time = 0;
+ struct timeval before, after;
+
+ do_gettimeofday(&before);
+ if (max_stall_time == 0)
+ start_time = before;
+#endif
+
+ timediff = 0;
+
+ while (1) {
+ u32 edm = bcm2835_sdhost_read(host, SDEDM);
+ if ((edm & 0xf) == 1)
+ break;
+ timediff++;
+ if (timediff > 5000000) {
+#ifdef DEBUG
+ do_gettimeofday(&after);
+ timediff = (after.tv_sec - before.tv_sec)*1000000 +
+ (after.tv_usec - before.tv_usec);
+
+ pr_err(" wait_write_complete - still waiting after %dus\n",
+ timediff);
+#else
+ pr_err(" wait_write_complete - still waiting after %d retries\n",
+ timediff);
+#endif
+ bcm2835_sdhost_dumpregs(host);
+ host->data->error = -ETIMEDOUT;
+ return;
+ }
+ }
+
+#ifdef DEBUG
+ do_gettimeofday(&after);
+ timediff = (after.tv_sec - before.tv_sec)*1000000 + (after.tv_usec - before.tv_usec);
+
+ total_stall_time += timediff;
+ if (timediff > max_stall_time)
+ max_stall_time = timediff;
+
+ if ((after.tv_sec - start_time.tv_sec) > 10) {
+ pr_debug(" wait_write_complete - max wait %dus, total %dus\n",
+ max_stall_time, total_stall_time);
+ start_time = after;
+ max_stall_time = 0;
+ total_stall_time = 0;
+ }
+#endif
+}
+
+static void bcm2835_sdhost_finish_data(struct bcm2835_host *host);
+
+static void bcm2835_sdhost_dma_complete(void *param)
+{
+ struct bcm2835_host *host = param;
+ struct dma_chan *dma_chan;
+ unsigned long flags;
+ u32 dir_data;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ if (host->data) {
+ bool write_complete;
+ if (USE_BLOCK_IRQ)
+ write_complete = bcm2835_sdhost_is_write_complete(host);
+ else {
+ bcm2835_sdhost_wait_write_complete(host);
+ write_complete = true;
+ }
+ pr_debug("dma_complete() - write_complete=%d\n",
+ write_complete);
+
+ if (write_complete || (host->data->flags & MMC_DATA_READ))
+ {
+ if (write_complete) {
+ dma_chan = host->dma_chan_tx;
+ dir_data = DMA_TO_DEVICE;
+ } else {
+ dma_chan = host->dma_chan_rx;
+ dir_data = DMA_FROM_DEVICE;
+ }
+
+ dma_unmap_sg(dma_chan->device->dev,
+ host->data->sg, host->data->sg_len,
+ dir_data);
+
+ bcm2835_sdhost_finish_data(host);
+ }
+ }
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_read_block_pio(struct bcm2835_host *host)
+{
+ unsigned long flags;
+ size_t blksize, len;
+ u32 *buf;
+
+ blksize = host->data->blksz;
+
+ local_irq_save(flags);
+
+ while (blksize) {
+ if (!sg_miter_next(&host->sg_miter))
+ BUG();
+
+ len = min(host->sg_miter.length, blksize);
+ BUG_ON(len % 4);
+
+ blksize -= len;
+ host->sg_miter.consumed = len;
+
+ buf = (u32 *)host->sg_miter.addr;
+
+ while (len) {
+ while (1) {
+ u32 hsts;
+ hsts = bcm2835_sdhost_read(host, SDHSTS);
+ if (hsts & SDHSTS_DATA_FLAG)
+ break;
+
+ if (hsts & SDHSTS_ERROR_MASK) {
+ pr_err("%s: Transfer error - HSTS %x, HBCT %x - %x left\n",
+ mmc_hostname(host->mmc),
+ hsts,
+ bcm2835_sdhost_read(host, SDHBCT),
+ blksize + len);
+ if (hsts & SDHSTS_REW_TIME_OUT)
+ host->data->error = -ETIMEDOUT;
+ else if (hsts & (SDHSTS_CRC16_ERROR ||
+ SDHSTS_CRC7_ERROR))
+ host->data->error = -EILSEQ;
+ else {
+ pr_err("%s: unexpected data error\n",
+ mmc_hostname(host->mmc));
+ bcm2835_sdhost_dumpregs(host);
+ host->cmd->error = -EIO;
+ }
+ }
+ }
+
+ *(buf++) = bcm2835_sdhost_read(host, SDDATA);
+ len -= 4;
+ }
+ }
+
+ sg_miter_stop(&host->sg_miter);
+
+ local_irq_restore(flags);
+}
+
+static void bcm2835_sdhost_write_block_pio(struct bcm2835_host *host)
+{
+ unsigned long flags;
+ size_t blksize, len;
+ u32 *buf;
+
+ blksize = host->data->blksz;
+
+ local_irq_save(flags);
+
+ while (blksize) {
+ if (!sg_miter_next(&host->sg_miter))
+ BUG();
+
+ len = min(host->sg_miter.length, blksize);
+ BUG_ON(len % 4);
+
+ blksize -= len;
+ host->sg_miter.consumed = len;
+
+ buf = host->sg_miter.addr;
+
+ while (len) {
+ while (!(bcm2835_sdhost_read(host, SDHSTS) & SDHSTS_DATA_FLAG))
+ continue;
+ bcm2835_sdhost_write(host, *(buf++), SDDATA);
+ len -= 4;
+ }
+ }
+
+ sg_miter_stop(&host->sg_miter);
+
+ local_irq_restore(flags);
+}
+
+
+static void bcm2835_sdhost_transfer_pio(struct bcm2835_host *host)
+{
+ BUG_ON(!host->data);
+
+ if (host->data->flags & MMC_DATA_READ)
+ bcm2835_sdhost_read_block_pio(host);
+ else
+ bcm2835_sdhost_write_block_pio(host);
+}
+
+
+static void bcm2835_sdhost_transfer_dma(struct bcm2835_host *host)
+{
+ u32 len, dir_data, dir_slave;
+ struct dma_async_tx_descriptor *desc = NULL;
+ struct dma_chan *dma_chan;
+
+ pr_debug("bcm2835_sdhost_transfer_dma()\n");
+
+ WARN_ON(!host->data);
+
+ if (!host->data)
+ return;
+
+ if (host->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;
+ }
+
+ BUG_ON(!dma_chan->device);
+ BUG_ON(!dma_chan->device->dev);
+ BUG_ON(!host->data->sg);
+
+ len = dma_map_sg(dma_chan->device->dev, host->data->sg,
+ host->data->sg_len, dir_data);
+ if (len > 0) {
+ desc = dmaengine_prep_slave_sg(dma_chan, host->data->sg,
+ len, dir_slave,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ } else {
+ dev_err(mmc_dev(host->mmc), "dma_map_sg returned zero length\n");
+ }
+ if (desc) {
+ desc->callback = bcm2835_sdhost_dma_complete;
+ desc->callback_param = host;
+ dmaengine_submit(desc);
+ dma_async_issue_pending(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->use_dma)
+ 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);
+
+ if (!data)
+ return;
+
+ /* Sanity checks */
+ BUG_ON(data->blksz * data->blocks > 524288);
+ BUG_ON(data->blksz > host->mmc->max_blk_size);
+ BUG_ON(data->blocks > 65535);
+
+ host->data = data;
+ host->data_complete = 0;
+ host->flush_fifo = 0;
+ host->data->bytes_xfered = 0;
+
+ if (!host->use_dma) {
+ int flags;
+
+ 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;
+ }
+
+ host->use_dma = host->have_dma && data->blocks > PIO_DMA_BARRIER;
+
+ bcm2835_sdhost_set_transfer_irqs(host);
+
+ bcm2835_sdhost_write(host, data->blksz, SDHBCT);
+ if (host->use_dma)
+ bcm2835_sdhost_write(host, data->blocks, SDHBLC);
+
+ BUG_ON(!host->data);
+}
+
+
+void bcm2835_sdhost_send_command(struct bcm2835_host *host, struct mmc_command *cmd)
+{
+ u32 sdcmd;
+ unsigned long timeout;
+
+ WARN_ON(host->cmd);
+
+ if (1) {
+ pr_debug("bcm2835_sdhost_send_command: %08x %08x (flags %x)\n",
+ cmd->opcode, cmd->arg, (cmd->flags & 0xff) | (cmd->data ? cmd->data->flags : 0));
+ if (cmd->data)
+ pr_debug("bcm2835_sdhost_send_command: %s %d*%x\n",
+ (cmd->data->flags & MMC_DATA_READ) ?
+ "read" : "write", cmd->data->blocks,
+ cmd->data->blksz);
+ }
+
+ /* Wait max 10 ms */
+ timeout = 1000;
+
+ 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 = -EIO;
+ tasklet_schedule(&host->finish_tasklet);
+ return;
+ }
+ timeout--;
+ udelay(10);
+ }
+
+ if ((1000-timeout)/100 > 1 && (1000-timeout)/100 > host->max_delay) {
+ host->max_delay = (1000-timeout)/100;
+ pr_warning("Warning: SDHost controller hung for %d ms\n", host->max_delay);
+ }
+
+ timeout = jiffies;
+#ifdef CONFIG_ARCH_BCM2835
+ if (!cmd->data && cmd->busy_timeout > 9000)
+ timeout += DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ;
+ else
+#endif
+ timeout += 10 * HZ;
+ mod_timer(&host->timer, timeout);
+
+ host->cmd = cmd;
+
+ bcm2835_sdhost_prepare_data(host, cmd);
+
+ bcm2835_sdhost_write(host, cmd->arg, SDARG);
+
+ 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;
+ }
+
+ sdcmd = cmd->opcode & SDCMD_CMD_MASK;
+
+ 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 = 1;
+ }
+ }
+
+ if (cmd->data) {
+ if (host->delay_after_stop) {
+ struct timeval now;
+ int time_since_stop;
+ do_gettimeofday(&now);
+ time_since_stop = (now.tv_sec - host->stop_time.tv_sec);
+ if (time_since_stop < 2) {
+ /* Possibly less than one second */
+ time_since_stop = time_since_stop * 1000000 +
+ (now.tv_usec - host->stop_time.tv_usec);
+ if (time_since_stop < host->delay_after_stop)
+ udelay(host->delay_after_stop -
+ time_since_stop);
+ }
+ }
+
+ 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);
+}
+
+
+static void bcm2835_sdhost_finish_command(struct bcm2835_host *host);
+static void bcm2835_sdhost_transfer_complete(struct bcm2835_host *host);
+
+static void bcm2835_sdhost_finish_data(struct bcm2835_host *host)
+{
+ struct mmc_data *data;
+
+ data = host->data;
+ BUG_ON(!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);
+
+ if (data->error) {
+ data->bytes_xfered = 0;
+ } else
+ data->bytes_xfered = data->blksz * data->blocks;
+
+ host->data_complete = 1;
+
+ 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);
+}
+
+
+static void bcm2835_sdhost_transfer_complete(struct bcm2835_host *host)
+{
+ struct mmc_data *data;
+
+ BUG_ON(host->cmd);
+ BUG_ON(!host->data);
+ BUG_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);
+
+ if (data->error)
+ /*
+ * The controller needs a reset of internal state machines
+ * upon error conditions.
+ */
+ bcm2835_sdhost_reset(host);
+
+ /*
+ * Need to send CMD12 if -
+ * a) open-ended multiblock transfer (no CMD23)
+ * b) error in multiblock transfer
+ */
+ if (data->stop &&
+ (data->error ||
+ !host->mrq->sbc)) {
+ host->flush_fifo = 1;
+ bcm2835_sdhost_send_command(host, data->stop);
+ if (host->delay_after_stop)
+ do_gettimeofday(&host->stop_time);
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host);
+ } else {
+ tasklet_schedule(&host->finish_tasklet);
+ }
+}
+
+static void bcm2835_sdhost_finish_command(struct bcm2835_host *host)
+{
+ u32 sdcmd;
+ int timeout = 1000;
+#ifdef DEBUG
+ struct timeval before, after;
+ int timediff = 0;
+#endif
+
+ pr_debug("finish_command(%x)\n", bcm2835_sdhost_read(host, SDCMD));
+
+ BUG_ON(!host->cmd || !host->mrq);
+
+#ifdef DEBUG
+ do_gettimeofday(&before);
+#endif
+ for (sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ (sdcmd & SDCMD_NEW_FLAG) && timeout;
+ timeout--) {
+ if (host->flush_fifo) {
+ while (bcm2835_sdhost_read(host, SDHSTS) &
+ SDHSTS_DATA_FLAG)
+ (void)bcm2835_sdhost_read(host, SDDATA);
+ }
+ udelay(10);
+ sdcmd = bcm2835_sdhost_read(host, SDCMD);
+ }
+#ifdef DEBUG
+ do_gettimeofday(&after);
+ timediff = (after.tv_sec - before.tv_sec)*1000000 +
+ (after.tv_usec - before.tv_usec);
+
+ pr_debug(" finish_command - waited %dus\n", timediff);
+#endif
+
+ if (timeout == 0) {
+ 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;
+ }
+
+ if (host->flush_fifo) {
+ for (timeout = 100;
+ (bcm2835_sdhost_read(host, SDHSTS) & SDHSTS_DATA_FLAG) && timeout;
+ timeout--) {
+ (void)bcm2835_sdhost_read(host, SDDATA);
+ }
+ host->flush_fifo = 0;
+ if (timeout == 0) {
+ pr_err("%s: FIFO never drained.\n",
+ mmc_hostname(host->mmc));
+ bcm2835_sdhost_dumpregs(host);
+ host->cmd->error = -EIO;
+ tasklet_schedule(&host->finish_tasklet);
+ return;
+ }
+ }
+
+ /* Check for errors */
+ if (sdcmd & SDCMD_FAIL_FLAG)
+ {
+ u32 sdhsts = bcm2835_sdhost_read(host, SDHSTS);
+
+ pr_debug("%s: error detected - CMD %x, HSTS %03x, EDM %x\n",
+ mmc_hostname(host->mmc), sdcmd, sdhsts,
+ bcm2835_sdhost_read(host, SDEDM));
+
+ if (sdhsts & SDHSTS_CMD_TIME_OUT)
+ host->cmd->error = -ETIMEDOUT;
+ else
+ {
+ pr_err("%s: unexpected command error\n",
+ mmc_hostname(host->mmc));
+ bcm2835_sdhost_dumpregs(host);
+ host->cmd->error = -EIO;
+ }
+ 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("bcm2835_sdhost_finish_command: %08x %08x %08x %08x\n",
+ 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("bcm2835_sdhost_finish_command: %08x\n",
+ host->cmd->resp[0]);
+ }
+ }
+
+ host->cmd->error = 0;
+
+ if (host->cmd == host->mrq->sbc) {
+ /* Finished CMD23, now send actual command. */
+ host->cmd = NULL;
+ bcm2835_sdhost_send_command(host, host->mrq->cmd);
+
+ if (host->cmd->data && host->use_dma)
+ /* DMA transfer starts now, PIO starts after irq */
+ bcm2835_sdhost_transfer_dma(host);
+
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host);
+ } 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_timer(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);
+ }
+ }
+
+ mmiowb();
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void bcm2835_sdhost_enable_sdio_irq_nolock(struct bcm2835_host *host, int enable)
+{
+ if (enable)
+ host->hcfg |= SDHCFG_SDIO_IRPT_EN;
+ else
+ host->hcfg &= ~SDHCFG_SDIO_IRPT_EN;
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+ mmiowb();
+}
+
+static void bcm2835_sdhost_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+ struct bcm2835_host *host = mmc_priv(mmc);
+ unsigned long flags;
+
+ pr_debug("bcm2835_sdhost_enable_sdio_irq(%d)\n", enable);
+ spin_lock_irqsave(&host->lock, flags);
+ bcm2835_sdhost_enable_sdio_irq_nolock(host, enable);
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static u32 bcm2835_sdhost_busy_irq(struct bcm2835_host *host, u32 intmask)
+{
+ const u32 handled = (SDHSTS_CMD_TIME_OUT | SDHSTS_CRC16_ERROR |
+ SDHSTS_CRC7_ERROR | SDHSTS_FIFO_ERROR);
+
+ 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 0;
+ }
+
+ 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 0;
+ }
+ host->use_busy = 0;
+
+ if (intmask & SDHSTS_CMD_TIME_OUT)
+ host->cmd->error = -ETIMEDOUT;
+ else if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_CRC7_ERROR |
+ SDHSTS_FIFO_ERROR))
+ host->cmd->error = -EILSEQ;
+
+ if (host->cmd->error)
+ tasklet_schedule(&host->finish_tasklet);
+ else
+ bcm2835_sdhost_finish_command(host);
+
+ return handled;
+}
+
+static u32 bcm2835_sdhost_data_irq(struct bcm2835_host *host, u32 intmask)
+{
+ const u32 handled = (SDHSTS_CMD_TIME_OUT | SDHSTS_CRC16_ERROR |
+ SDHSTS_CRC7_ERROR | SDHSTS_FIFO_ERROR);
+
+ /* 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 0;
+
+ // XXX FIFO_ERROR
+ if (intmask & SDHSTS_CMD_TIME_OUT)
+ host->cmd->error = -ETIMEDOUT;
+ else if ((intmask & (SDHSTS_CRC16_ERROR | SDHSTS_CRC7_ERROR)) &&
+ ((bcm2835_sdhost_read(host, SDCMD) & SDCMD_CMD_MASK)
+ != MMC_BUS_TEST_R))
+ host->cmd->error = -EILSEQ;
+
+ /* Use the block interrupt for writes after the first block */
+ if (host->data->flags & MMC_DATA_WRITE) {
+ host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
+ host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
+ bcm2835_sdhost_write(host, host->hcfg, SDHCFG);
+ if (host->data->error)
+ bcm2835_sdhost_finish_data(host);
+ else
+ bcm2835_sdhost_transfer_pio(host);
+ } else {
+ if (!host->data->error) {
+ bcm2835_sdhost_transfer_pio(host);
+ host->blocks--;
+ }
+ if ((host->blocks == 0) || host->data->error)
+ bcm2835_sdhost_finish_data(host);
+ }
+
+ return handled;
+}
+
+static u32 bcm2835_sdhost_block_irq(struct bcm2835_host *host, u32 intmask)
+{
+ struct dma_chan *dma_chan;
+ u32 dir_data;
+ const u32 handled = (SDHSTS_CMD_TIME_OUT | SDHSTS_CRC16_ERROR |
+ SDHSTS_CRC7_ERROR | SDHSTS_FIFO_ERROR);
+
+ 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 handled;
+ }
+
+ if (intmask & SDHSTS_CMD_TIME_OUT)
+ host->cmd->error = -ETIMEDOUT;
+ else if ((intmask & (SDHSTS_CRC16_ERROR | SDHSTS_CRC7_ERROR)) &&
+ ((bcm2835_sdhost_read(host, SDCMD) & SDCMD_CMD_MASK)
+ != MMC_BUS_TEST_R))
+ host->cmd->error = -EILSEQ;
+
+ if (!host->use_dma) {
+ BUG_ON(!host->blocks);
+ host->blocks--;
+ if ((host->blocks == 0) || host->data->error)
+ bcm2835_sdhost_finish_data(host);
+ else
+ bcm2835_sdhost_transfer_pio(host);
+ } else if (host->data->flags & MMC_DATA_WRITE) {
+ dma_chan = host->dma_chan_tx;
+ dir_data = DMA_TO_DEVICE;
+ dma_unmap_sg(dma_chan->device->dev,
+ host->data->sg, host->data->sg_len,
+ dir_data);
+
+ bcm2835_sdhost_finish_data(host);
+ }
+
+ return handled;
+}
+
+
+static irqreturn_t bcm2835_sdhost_irq(int irq, void *dev_id)
+{
+ irqreturn_t result = IRQ_NONE;
+ struct bcm2835_host *host = dev_id;
+ u32 unexpected = 0, early = 0;
+ int loops = 0;
+#ifndef CONFIG_ARCH_BCM2835
+ int cardint = 0;
+#endif
+ spin_lock(&host->lock);
+
+ for (loops = 0; loops < 1; loops++) {
+ u32 intmask, handled;
+
+ intmask = bcm2835_sdhost_read(host, SDHSTS);
+ handled = intmask & (SDHSTS_BUSY_IRPT |
+ SDHSTS_BLOCK_IRPT |
+ SDHSTS_SDIO_IRPT |
+ SDHSTS_DATA_FLAG);
+ if ((handled == SDHSTS_DATA_FLAG) && // XXX
+ (loops == 0) && !host->data) {
+ pr_err("%s: sdhost_irq data interrupt 0x%08x even "
+ "though no data operation was in progress.\n",
+ mmc_hostname(host->mmc),
+ (unsigned)intmask);
+
+ bcm2835_sdhost_dumpregs(host);
+ }
+
+ if (!handled)
+ break;
+
+ if (loops)
+ early |= handled;
+
+ result = IRQ_HANDLED;
+
+ /* Clear all interrupts and notifications */
+ bcm2835_sdhost_write(host, intmask, SDHSTS);
+
+ if (intmask & SDHSTS_BUSY_IRPT)
+ handled |= bcm2835_sdhost_busy_irq(host, intmask);
+
+ /* 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))
+ handled |= bcm2835_sdhost_data_irq(host, intmask);
+
+ if (intmask & SDHSTS_BLOCK_IRPT)
+ handled |= bcm2835_sdhost_block_irq(host, intmask);
+
+ if (intmask & SDHSTS_SDIO_IRPT) {
+#ifndef CONFIG_ARCH_BCM2835
+ cardint = 1;
+#else
+ bcm2835_sdhost_enable_sdio_irq_nolock(host, false);
+ host->thread_isr |= SDHSTS_SDIO_IRPT;
+ result = IRQ_WAKE_THREAD;
+#endif
+ }
+
+ unexpected |= (intmask & ~handled);
+ }
+
+ mmiowb();
+
+ spin_unlock(&host->lock);
+
+ if (early)
+ pr_debug("%s: early %x (loops %d)\n", mmc_hostname(host->mmc), early, loops);
+
+ if (unexpected) {
+ pr_err("%s: Unexpected interrupt 0x%08x.\n",
+ mmc_hostname(host->mmc), unexpected);
+ bcm2835_sdhost_dumpregs(host);
+ }
+
+#ifndef CONFIG_ARCH_BCM2835
+ if (cardint)
+ mmc_signal_sdio_irq(host->mmc);
+#endif
+
+ return result;
+}
+
+#ifdef CONFIG_ARCH_BCM2835
+static irqreturn_t bcm2835_sdhost_thread_irq(int irq, void *dev_id)
+{
+ struct bcm2835_host *host = dev_id;
+ unsigned long flags;
+ u32 isr;
+
+ spin_lock_irqsave(&host->lock, flags);
+ isr = host->thread_isr;
+ host->thread_isr = 0;
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ if (isr & SDHSTS_SDIO_IRPT) {
+ sdio_run_irqs(host->mmc);
+
+/* Is this necessary? Why re-enable an interrupt which is enabled?
+ spin_lock_irqsave(&host->lock, flags);
+ if (host->flags & SDHSTS_SDIO_IRPT_ENABLED)
+ bcm2835_sdhost_enable_sdio_irq_nolock(host, true);
+ spin_unlock_irqrestore(&host->lock, flags);
+*/
+ }
+
+ return isr ? IRQ_HANDLED : IRQ_NONE;
+}
+#endif
+
+
+
+void bcm2835_sdhost_set_clock(struct bcm2835_host *host, unsigned int clock)
+{
+ int div = 0; /* Initialized for compiler warning */
+ unsigned int input_clock = clock;
+
+ if (host->overclock_50 && (clock == 50000000))
+ clock = host->overclock_50 * 1000000 + 999999;
+
+ /* 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;
+
+ if ((clock > input_clock) && (clock > host->max_overclock)) {
+ pr_warn("%s: Overclocking to %dHz\n",
+ mmc_hostname(host->mmc), clock);
+ host->max_overclock = clock;
+ }
+
+ host->cdiv = div;
+ bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
+
+ pr_debug(DRIVER_NAME ": clock=%d -> max_clk=%d, cdiv=%x (actual clock %d)\n",
+ input_clock, host->max_clk, host->cdiv, host->mmc->actual_clock);
+}
+
+static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+ struct bcm2835_host *host;
+ unsigned long flags;
+
+ if (1) {
+ struct mmc_command *cmd = mrq->cmd;
+ const char *src = "cmd";
+ BUG_ON(!cmd);
+ pr_debug("bcm2835_sdhost_request: %s %08x %08x (flags %x)\n",
+ src, cmd->opcode, cmd->arg, cmd->flags);
+ if (cmd->data)
+ pr_debug("bcm2835_sdhost_request: %s %d*%d\n",
+ (cmd->data->flags & MMC_DATA_READ) ?
+ "read" : "write", cmd->data->blocks,
+ cmd->data->blksz);
+ }
+
+ 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;
+ }
+
+ host = mmc_priv(mmc);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ WARN_ON(host->mrq != NULL);
+
+ host->mrq = mrq;
+
+ if (mrq->sbc)
+ bcm2835_sdhost_send_command(host, mrq->sbc);
+ else
+ bcm2835_sdhost_send_command(host, mrq->cmd);
+
+ mmiowb();
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ if (!mrq->sbc && mrq->cmd->data && host->use_dma)
+ /* DMA transfer starts now, PIO starts after irq */
+ bcm2835_sdhost_transfer_dma(host);
+
+ if (!host->use_busy)
+ bcm2835_sdhost_finish_command(host);
+}
+
+
+static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+
+ struct bcm2835_host *host = mmc_priv(mmc);
+ unsigned long flags;
+
+ pr_debug("bcm2835_sdhost_set_ios: clock %d, pwr %d, bus_width %d, timing %d, vdd %d, drv_type %d\n",
+ ios->clock, ios->power_mode, ios->bus_width,
+ ios->timing, ios->signal_voltage, ios->drv_type);
+
+ 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);
+
+ mmiowb();
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static int bcm2835_sdhost_multi_io_quirk(struct mmc_card *card,
+ unsigned int direction,
+ u32 blk_pos, int blk_size)
+{
+ /* There is a bug in the host controller hardware that makes
+ reading the final sector of the card as part of a multiple read
+ problematic. Detect that case and shorten the read accordingly.
+ */
+ /* csd.capacity is in weird units - convert to sectors */
+ u32 card_sectors = (card->csd.capacity << (card->csd.read_blkbits - 9));
+
+ if ((direction == MMC_DATA_READ) &&
+ ((blk_pos + blk_size) == card_sectors))
+ blk_size--;
+
+ return blk_size;
+}
+
+
+static struct mmc_host_ops bcm2835_sdhost_ops = {
+ .request = bcm2835_sdhost_request,
+ .set_ios = bcm2835_sdhost_set_ios,
+ .enable_sdio_irq = bcm2835_sdhost_enable_sdio_irq,
+ .multi_io_quirk = bcm2835_sdhost_multi_io_quirk,
+};
+
+
+static void bcm2835_sdhost_tasklet_finish(unsigned long param)
+{
+ struct bcm2835_host *host;
+ unsigned long flags;
+ struct mmc_request *mrq;
+
+ 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;
+
+ /*
+ * The controller needs a reset of internal state machines
+ * upon error conditions.
+ */
+ if (((mrq->cmd && mrq->cmd->error) ||
+ (mrq->data && (mrq->data->error ||
+ (mrq->data->stop && mrq->data->stop->error))))) {
+
+ bcm2835_sdhost_reset(host);
+ }
+
+ host->mrq = NULL;
+ host->cmd = NULL;
+ host->data = NULL;
+
+ mmiowb();
+
+ spin_unlock_irqrestore(&host->lock, flags);
+ mmc_request_done(host->mmc, mrq);
+}
+
+
+
+int bcm2835_sdhost_add_host(struct bcm2835_host *host)
+{
+ struct mmc_host *mmc;
+ struct dma_slave_config cfg;
+ int ret;
+
+ mmc = host->mmc;
+
+ bcm2835_sdhost_reset(host);
+
+ mmc->f_max = host->max_clk;
+ mmc->f_min = host->max_clk / SDCDIV_MAX_CDIV;
+
+ /* SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK */
+ host->timeout_clk = mmc->f_max / 1000;
+#ifdef CONFIG_ARCH_BCM2835
+ mmc->max_busy_timeout = (1 << 27) / host->timeout_clk;
+#endif
+ /* host controller capabilities */
+ mmc->caps |= /* MMC_CAP_SDIO_IRQ |*/ MMC_CAP_4_BIT_DATA |
+ MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED |
+ MMC_CAP_NEEDS_POLL |
+ (ALLOW_CMD23 * MMC_CAP_CMD23);
+
+ spin_lock_init(&host->lock);
+
+ if (host->allow_dma) {
+ if (!host->dma_chan_tx || !host->dma_chan_rx ||
+ IS_ERR(host->dma_chan_tx) || IS_ERR(host->dma_chan_rx)) {
+ pr_err("%s: Unable to initialise DMA channels. Falling back to PIO\n", DRIVER_NAME);
+ host->have_dma = false;
+ } else {
+ pr_info("DMA channels allocated for the SDHost driver");
+ host->have_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);
+
+ 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);
+ }
+ } else {
+ pr_info("Forcing PIO mode\n");
+ host->have_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);
+
+ setup_timer(&host->timer, bcm2835_sdhost_timeout_timer, (unsigned long)host);
+
+ bcm2835_sdhost_init(host, 0);
+#ifndef CONFIG_ARCH_BCM2835
+ ret = request_irq(host->irq, bcm2835_sdhost_irq, 0 /*IRQF_SHARED*/,
+ mmc_hostname(mmc), host);
+#else
+ ret = request_threaded_irq(host->irq, bcm2835_sdhost_irq, bcm2835_sdhost_thread_irq,
+ IRQF_SHARED, mmc_hostname(mmc), host);
+#endif
+ if (ret) {
+ pr_err("%s: Failed to request IRQ %d: %d\n",
+ mmc_hostname(mmc), host->irq, ret);
+ goto untasklet;
+ }
+
+ mmiowb();
+ mmc_add_host(mmc);
+
+ pr_info("Load BCM2835 SDHost driver\n");
+ if (host->delay_after_stop)
+ pr_info("BCM2835 SDHost: delay_after_stop=%dus\n",
+ host->delay_after_stop);
+
+ 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 device_node *node = dev->of_node;
+ 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->timeout = msecs_to_jiffies(1000);
+ 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;
+ }
+
+ host->phys_addr = iomem->start + BCM2835_VCMMU_SHIFT;
+ 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->allow_dma = ALLOW_DMA;
+
+ if (node) {
+ /* Read any custom properties */
+ of_property_read_u32(node,
+ "brcm,delay-after-stop",
+ &host->delay_after_stop);
+ of_property_read_u32(node,
+ "brcm,overclock-50",
+ &host->overclock_50);
+ host->allow_dma = ALLOW_DMA &&
+ !of_property_read_bool(node, "brcm,force-pio");
+ }
+
+ if (host->allow_dma) {
+ if (node) {
+ host->dma_chan_tx =
+ dma_request_slave_channel(dev, "tx");
+ host->dma_chan_rx =
+ dma_request_slave_channel(dev, "rx");
+ } else {
+ dma_cap_mask_t mask;
+
+ dma_cap_zero(mask);
+ /* we don't care about the channel, any would work */
+ dma_cap_set(DMA_SLAVE, mask);
+ host->dma_chan_tx =
+ dma_request_channel(mask, NULL, NULL);
+ host->dma_chan_rx =
+ dma_request_channel(mask, NULL, NULL);
+ }
+ }
+
+ clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "could not get clk\n");
+ ret = PTR_ERR(clk);
+ 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);
+
+ if (node)
+ mmc_of_parse(mmc);
+ else
+ mmc->caps |= MMC_CAP_4_BIT_DATA;
+
+ 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 = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .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");