diff options
Diffstat (limited to 'drivers/mmc/host/bcm2835.c')
| -rw-r--r-- | drivers/mmc/host/bcm2835.c | 1465 |
1 files changed, 1465 insertions, 0 deletions
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c new file mode 100644 index 000000000000..7d1b0db7fbb7 --- /dev/null +++ b/drivers/mmc/host/bcm2835.c @@ -0,0 +1,1465 @@ +/* + * bcm2835 sdhost driver. + * + * The 2835 has two SD controllers: The Arasan sdhci controller + * (supported by the iproc driver) and a custom sdhost controller + * (supported by this driver). + * + * The sdhci controller supports both sdcard and sdio. The sdhost + * controller supports the sdcard only, but has better performance. + * Also note that the rpi3 has sdio wifi, so driving the sdcard with + * the sdhost controller allows to use the sdhci controller for wifi + * support. + * + * The configuration is done by devicetree via pin muxing. Both + * SD controller are available on the same pins (2 pin groups = pin 22 + * to 27 + pin 48 to 53). So it's possible to use both SD controllers + * at the same time with different pin groups. + * + * Author: Phil Elwell <phil@raspberrypi.org> + * Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd. + * + * Based on + * mmc-bcm2835.c by Gellert Weisz + * which is, in turn, based on + * sdhci-bcm2708.c by Broadcom + * sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko + * sdhci.c and sdhci-pci.c by Pierre Ossman + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/highmem.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/scatterlist.h> +#include <linux/time.h> +#include <linux/workqueue.h> + +#include <linux/mmc/host.h> +#include <linux/mmc/mmc.h> +#include <linux/mmc/sd.h> + +#define SDCMD 0x00 /* Command to SD card - 16 R/W */ +#define SDARG 0x04 /* Argument to SD card - 32 R/W */ +#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */ +#define SDCDIV 0x0c /* Start value for clock divider - 11 R/W */ +#define SDRSP0 0x10 /* SD card response (31:0) - 32 R */ +#define SDRSP1 0x14 /* SD card response (63:32) - 32 R */ +#define SDRSP2 0x18 /* SD card response (95:64) - 32 R */ +#define SDRSP3 0x1c /* SD card response (127:96) - 32 R */ +#define SDHSTS 0x20 /* SD host status - 11 R/W */ +#define SDVDD 0x30 /* SD card power control - 1 R/W */ +#define SDEDM 0x34 /* Emergency Debug Mode - 13 R/W */ +#define SDHCFG 0x38 /* Host configuration - 2 R/W */ +#define SDHBCT 0x3c /* Host byte count (debug) - 32 R/W */ +#define SDDATA 0x40 /* Data to/from SD card - 32 R/W */ +#define SDHBLC 0x50 /* Host block count (SDIO/SDHC) - 9 R/W */ + +#define SDCMD_NEW_FLAG 0x8000 +#define SDCMD_FAIL_FLAG 0x4000 +#define SDCMD_BUSYWAIT 0x800 +#define SDCMD_NO_RESPONSE 0x400 +#define SDCMD_LONG_RESPONSE 0x200 +#define SDCMD_WRITE_CMD 0x80 +#define SDCMD_READ_CMD 0x40 +#define SDCMD_CMD_MASK 0x3f + +#define SDCDIV_MAX_CDIV 0x7ff + +#define SDHSTS_BUSY_IRPT 0x400 +#define SDHSTS_BLOCK_IRPT 0x200 +#define SDHSTS_SDIO_IRPT 0x100 +#define SDHSTS_REW_TIME_OUT 0x80 +#define SDHSTS_CMD_TIME_OUT 0x40 +#define SDHSTS_CRC16_ERROR 0x20 +#define SDHSTS_CRC7_ERROR 0x10 +#define SDHSTS_FIFO_ERROR 0x08 +/* Reserved */ +/* Reserved */ +#define SDHSTS_DATA_FLAG 0x01 + +#define SDHSTS_TRANSFER_ERROR_MASK (SDHSTS_CRC7_ERROR | \ + SDHSTS_CRC16_ERROR | \ + SDHSTS_REW_TIME_OUT | \ + SDHSTS_FIFO_ERROR) + +#define SDHSTS_ERROR_MASK (SDHSTS_CMD_TIME_OUT | \ + SDHSTS_TRANSFER_ERROR_MASK) + +#define SDHCFG_BUSY_IRPT_EN BIT(10) +#define SDHCFG_BLOCK_IRPT_EN BIT(8) +#define SDHCFG_SDIO_IRPT_EN BIT(5) +#define SDHCFG_DATA_IRPT_EN BIT(4) +#define SDHCFG_SLOW_CARD BIT(3) +#define SDHCFG_WIDE_EXT_BUS BIT(2) +#define SDHCFG_WIDE_INT_BUS BIT(1) +#define SDHCFG_REL_CMD_LINE BIT(0) + +#define SDVDD_POWER_OFF 0 +#define SDVDD_POWER_ON 1 + +#define SDEDM_FORCE_DATA_MODE BIT(19) +#define SDEDM_CLOCK_PULSE BIT(20) +#define SDEDM_BYPASS BIT(21) + +#define SDEDM_WRITE_THRESHOLD_SHIFT 9 +#define SDEDM_READ_THRESHOLD_SHIFT 14 +#define SDEDM_THRESHOLD_MASK 0x1f + +#define SDEDM_FSM_MASK 0xf +#define SDEDM_FSM_IDENTMODE 0x0 +#define SDEDM_FSM_DATAMODE 0x1 +#define SDEDM_FSM_READDATA 0x2 +#define SDEDM_FSM_WRITEDATA 0x3 +#define SDEDM_FSM_READWAIT 0x4 +#define SDEDM_FSM_READCRC 0x5 +#define SDEDM_FSM_WRITECRC 0x6 +#define SDEDM_FSM_WRITEWAIT1 0x7 +#define SDEDM_FSM_POWERDOWN 0x8 +#define SDEDM_FSM_POWERUP 0x9 +#define SDEDM_FSM_WRITESTART1 0xa +#define SDEDM_FSM_WRITESTART2 0xb +#define SDEDM_FSM_GENPULSES 0xc +#define SDEDM_FSM_WRITEWAIT2 0xd +#define SDEDM_FSM_STARTPOWDOWN 0xf + +#define SDDATA_FIFO_WORDS 16 + +#define FIFO_READ_THRESHOLD 4 +#define FIFO_WRITE_THRESHOLD 4 +#define SDDATA_FIFO_PIO_BURST 8 + +#define PIO_THRESHOLD 1 /* Maximum block count for PIO (0 = always DMA) */ + +struct bcm2835_host { + spinlock_t lock; + struct mutex mutex; + + void __iomem *ioaddr; + u32 phys_addr; + + struct mmc_host *mmc; + struct platform_device *pdev; + + int clock; /* Current clock speed */ + unsigned int max_clk; /* Max possible freq */ + struct work_struct dma_work; + struct delayed_work timeout_work; /* Timer for timeouts */ + struct sg_mapping_iter sg_miter; /* SG state for PIO */ + unsigned int blocks; /* remaining PIO blocks */ + int irq; /* Device IRQ */ + + u32 ns_per_fifo_word; + + /* cached registers */ + u32 hcfg; + u32 cdiv; + + struct mmc_request *mrq; /* Current request */ + struct mmc_command *cmd; /* Current command */ + struct mmc_data *data; /* Current data request */ + bool data_complete:1;/* Data finished before cmd */ + bool use_busy:1; /* Wait for busy interrupt */ + bool use_sbc:1; /* Send CMD23 */ + + /* for threaded irq handler */ + bool irq_block; + bool irq_busy; + bool irq_data; + + /* DMA part */ + struct dma_chan *dma_chan_rxtx; + struct dma_chan *dma_chan; + struct dma_slave_config dma_cfg_rx; + struct dma_slave_config dma_cfg_tx; + struct dma_async_tx_descriptor *dma_desc; + u32 dma_dir; + u32 drain_words; + struct page *drain_page; + u32 drain_offset; + bool use_dma; +}; + +static void bcm2835_dumpcmd(struct bcm2835_host *host, struct mmc_command *cmd, + const char *label) +{ + struct device *dev = &host->pdev->dev; + + if (!cmd) + return; + + dev_dbg(dev, "%c%s op %d arg 0x%x flags 0x%x - resp %08x %08x %08x %08x, err %d\n", + (cmd == host->cmd) ? '>' : ' ', + label, cmd->opcode, cmd->arg, cmd->flags, + cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3], + cmd->error); +} + +static void bcm2835_dumpregs(struct bcm2835_host *host) +{ + struct mmc_request *mrq = host->mrq; + struct device *dev = &host->pdev->dev; + + if (mrq) { + bcm2835_dumpcmd(host, mrq->sbc, "sbc"); + bcm2835_dumpcmd(host, mrq->cmd, "cmd"); + if (mrq->data) { + dev_dbg(dev, "data blocks %x blksz %x - err %d\n", + mrq->data->blocks, + mrq->data->blksz, + mrq->data->error); + } + bcm2835_dumpcmd(host, mrq->stop, "stop"); + } + + dev_dbg(dev, "=========== REGISTER DUMP ===========\n"); + dev_dbg(dev, "SDCMD 0x%08x\n", readl(host->ioaddr + SDCMD)); + dev_dbg(dev, "SDARG 0x%08x\n", readl(host->ioaddr + SDARG)); + dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT)); + dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV)); + dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0)); + dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1)); + dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2)); + dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3)); + dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS)); + dev_dbg(dev, "SDVDD 0x%08x\n", readl(host->ioaddr + SDVDD)); + dev_dbg(dev, "SDEDM 0x%08x\n", readl(host->ioaddr + SDEDM)); + dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG)); + dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT)); + dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC)); + dev_dbg(dev, "===========================================\n"); +} + +static void bcm2835_reset_internal(struct bcm2835_host *host) +{ + u32 temp; + + writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD); + writel(0, host->ioaddr + SDCMD); + writel(0, host->ioaddr + SDARG); + writel(0xf00000, host->ioaddr + SDTOUT); + writel(0, host->ioaddr + SDCDIV); + writel(0x7f8, host->ioaddr + SDHSTS); /* Write 1s to clear */ + writel(0, host->ioaddr + SDHCFG); + writel(0, host->ioaddr + SDHBCT); + writel(0, host->ioaddr + SDHBLC); + + /* Limit fifo usage due to silicon bug */ + temp = readl(host->ioaddr + SDEDM); + temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) | + (SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT)); + temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) | + (FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT); + writel(temp, host->ioaddr + SDEDM); + msleep(20); + writel(SDVDD_POWER_ON, host->ioaddr + SDVDD); + msleep(20); + host->clock = 0; + writel(host->hcfg, host->ioaddr + SDHCFG); + writel(host->cdiv, host->ioaddr + SDCDIV); +} + +static void bcm2835_reset(struct mmc_host *mmc) +{ + struct bcm2835_host *host = mmc_priv(mmc); + + if (host->dma_chan) + dmaengine_terminate_sync(host->dma_chan); + bcm2835_reset_internal(host); +} + +static void bcm2835_finish_command(struct bcm2835_host *host); + +static void bcm2835_wait_transfer_complete(struct bcm2835_host *host) +{ + int timediff; + u32 alternate_idle; + + alternate_idle = (host->mrq->data->flags & MMC_DATA_READ) ? + SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1; + + timediff = 0; + + while (1) { + u32 edm, fsm; + + edm = readl(host->ioaddr + SDEDM); + fsm = edm & SDEDM_FSM_MASK; + + if ((fsm == SDEDM_FSM_IDENTMODE) || + (fsm == SDEDM_FSM_DATAMODE)) + break; + if (fsm == alternate_idle) { + writel(edm | SDEDM_FORCE_DATA_MODE, + host->ioaddr + SDEDM); + break; + } + + timediff++; + if (timediff == 100000) { + dev_err(&host->pdev->dev, + "wait_transfer_complete - still waiting after %d retries\n", + timediff); + bcm2835_dumpregs(host); + host->mrq->data->error = -ETIMEDOUT; + return; + } + cpu_relax(); + } +} + +static void bcm2835_dma_complete(void *param) +{ + struct bcm2835_host *host = param; + + schedule_work(&host->dma_work); +} + +static void bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read) +{ + unsigned long flags; + size_t blksize; + unsigned long wait_max; + + blksize = host->data->blksz; + + wait_max = jiffies + msecs_to_jiffies(500); + + local_irq_save(flags); + + while (blksize) { + int copy_words; + u32 hsts = 0; + size_t len; + u32 *buf; + + if (!sg_miter_next(&host->sg_miter)) { + host->data->error = -EINVAL; + break; + } + + len = min(host->sg_miter.length, blksize); + if (len % 4) { + host->data->error = -EINVAL; + break; + } + + blksize -= len; + host->sg_miter.consumed = len; + + buf = (u32 *)host->sg_miter.addr; + + copy_words = len / 4; + + while (copy_words) { + int burst_words, words; + u32 edm; + + burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words); + edm = readl(host->ioaddr + SDEDM); + if (is_read) + words = ((edm >> 4) & 0x1f); + else + words = SDDATA_FIFO_WORDS - ((edm >> 4) & 0x1f); + + if (words < burst_words) { + int fsm_state = (edm & SDEDM_FSM_MASK); + struct device *dev = &host->pdev->dev; + + if ((is_read && + (fsm_state != SDEDM_FSM_READDATA && + fsm_state != SDEDM_FSM_READWAIT && + fsm_state != SDEDM_FSM_READCRC)) || + (!is_read && + (fsm_state != SDEDM_FSM_WRITEDATA && + fsm_state != SDEDM_FSM_WRITESTART1 && + fsm_state != SDEDM_FSM_WRITESTART2))) { + hsts = readl(host->ioaddr + SDHSTS); + dev_err(dev, "fsm %x, hsts %08x\n", + fsm_state, hsts); + if (hsts & SDHSTS_ERROR_MASK) + break; + } + + if (time_after(jiffies, wait_max)) { + dev_err(dev, "PIO %s timeout - EDM %08x\n", + is_read ? "read" : "write", + edm); + hsts = SDHSTS_REW_TIME_OUT; + break; + } + ndelay((burst_words - words) * + host->ns_per_fifo_word); + continue; + } else if (words > copy_words) { + words = copy_words; + } + + copy_words -= words; + + while (words) { + if (is_read) + *(buf++) = readl(host->ioaddr + SDDATA); + else + writel(*(buf++), host->ioaddr + SDDATA); + words--; + } + } + + if (hsts & SDHSTS_ERROR_MASK) + break; + } + + sg_miter_stop(&host->sg_miter); + + local_irq_restore(flags); +} + +static void bcm2835_transfer_pio(struct bcm2835_host *host) +{ + struct device *dev = &host->pdev->dev; + u32 sdhsts; + bool is_read; + + is_read = (host->data->flags & MMC_DATA_READ) != 0; + bcm2835_transfer_block_pio(host, is_read); + + sdhsts = readl(host->ioaddr + SDHSTS); + if (sdhsts & (SDHSTS_CRC16_ERROR | + SDHSTS_CRC7_ERROR | + SDHSTS_FIFO_ERROR)) { + dev_err(dev, "%s transfer error - HSTS %08x\n", + is_read ? "read" : "write", sdhsts); + host->data->error = -EILSEQ; + } else if ((sdhsts & (SDHSTS_CMD_TIME_OUT | + SDHSTS_REW_TIME_OUT))) { + dev_err(dev, "%s timeout error - HSTS %08x\n", + is_read ? "read" : "write", sdhsts); + host->data->error = -ETIMEDOUT; + } +} + +static +void bcm2835_prepare_dma(struct bcm2835_host *host, struct mmc_data *data) +{ + int len, dir_data, dir_slave; + struct dma_async_tx_descriptor *desc = NULL; + struct dma_chan *dma_chan; + + dma_chan = host->dma_chan_rxtx; + if (data->flags & MMC_DATA_READ) { + dir_data = DMA_FROM_DEVICE; + dir_slave = DMA_DEV_TO_MEM; + } else { + dir_data = DMA_TO_DEVICE; + dir_slave = DMA_MEM_TO_DEV; + } + + /* The block doesn't manage the FIFO DREQs properly for + * multi-block transfers, so don't attempt to DMA the final + * few words. Unfortunately this requires the final sg entry + * to be trimmed. N.B. This code demands that the overspill + * is contained in a single sg entry. + */ + + host->drain_words = 0; + if ((data->blocks > 1) && (dir_data == DMA_FROM_DEVICE)) { + struct scatterlist *sg; + u32 len; + int i; + + len = min((u32)(FIFO_READ_THRESHOLD - 1) * 4, + (u32)data->blocks * data->blksz); + + for_each_sg(data->sg, sg, data->sg_len, i) { + if (sg_is_last(sg)) { + WARN_ON(sg->length < len); + sg->length -= len; + host->drain_page = sg_page(sg); + host->drain_offset = sg->offset + sg->length; + } + } + host->drain_words = len / 4; + } + + /* The parameters have already been validated, so this will not fail */ + (void)dmaengine_slave_config(dma_chan, + (dir_data == DMA_FROM_DEVICE) ? + &host->dma_cfg_rx : + &host->dma_cfg_tx); + + len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len, + dir_data); + + if (len > 0) { + desc = dmaengine_prep_slave_sg(dma_chan, data->sg, + len, dir_slave, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); + } + + if (desc) { + desc->callback = bcm2835_dma_complete; + desc->callback_param = host; + host->dma_desc = desc; + host->dma_chan = dma_chan; + host->dma_dir = dir_data; + } +} + +static void bcm2835_start_dma(struct bcm2835_host *host) +{ + dmaengine_submit(host->dma_desc); + dma_async_issue_pending(host->dma_chan); +} + +static void bcm2835_set_transfer_irqs(struct bcm2835_host *host) +{ + u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN | + SDHCFG_BUSY_IRPT_EN; + + if (host->dma_desc) { + host->hcfg = (host->hcfg & ~all_irqs) | + SDHCFG_BUSY_IRPT_EN; + } else { + host->hcfg = (host->hcfg & ~all_irqs) | + SDHCFG_DATA_IRPT_EN | + SDHCFG_BUSY_IRPT_EN; + } + + writel(host->hcfg, host->ioaddr + SDHCFG); +} + +static +void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_command *cmd) +{ + struct mmc_data *data = cmd->data; + + WARN_ON(host->data); + + host->data = data; + if (!data) + return; + + host->data_complete = false; + host->data->bytes_xfered = 0; + + if (!host->dma_desc) { + /* Use PIO */ + int flags = SG_MITER_ATOMIC; + + if (data->flags & MMC_DATA_READ) + flags |= SG_MITER_TO_SG; + else + flags |= SG_MITER_FROM_SG; + sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags); + host->blocks = data->blocks; + } + + bcm2835_set_transfer_irqs(host); + + writel(data->blksz, host->ioaddr + SDHBCT); + writel(data->blocks, host->ioaddr + SDHBLC); +} + +static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host, u32 max_ms) +{ + struct device *dev = &host->pdev->dev; + u32 value; + int ret; + + ret = readl_poll_timeout(host->ioaddr + SDCMD, value, + !(value & SDCMD_NEW_FLAG), 1, 10); + if (ret == -ETIMEDOUT) + /* if it takes a while make poll interval bigger */ + ret = readl_poll_timeout(host->ioaddr + SDCMD, value, + !(value & SDCMD_NEW_FLAG), + 10, max_ms * 1000); + if (ret == -ETIMEDOUT) + dev_err(dev, "%s: timeout (%d ms)\n", __func__, max_ms); + + return value; +} + +static void bcm2835_finish_request(struct bcm2835_host *host) +{ + struct dma_chan *terminate_chan = NULL; + struct mmc_request *mrq; + + cancel_delayed_work(&host->timeout_work); + + mrq = host->mrq; + + host->mrq = NULL; + host->cmd = NULL; + host->data = NULL; + + host->dma_desc = NULL; + terminate_chan = host->dma_chan; + host->dma_chan = NULL; + + if (terminate_chan) { + int err = dmaengine_terminate_all(terminate_chan); + + if (err) + dev_err(&host->pdev->dev, + "failed to terminate DMA (%d)\n", err); + } + + mmc_request_done(host->mmc, mrq); +} + +static +bool bcm2835_send_command(struct bcm2835_host *host, struct mmc_command *cmd) +{ + struct device *dev = &host->pdev->dev; + u32 sdcmd, sdhsts; + unsigned long timeout; + + WARN_ON(host->cmd); + + sdcmd = bcm2835_read_wait_sdcmd(host, 100); + if (sdcmd & SDCMD_NEW_FLAG) { + dev_err(dev, "previous command never completed.\n"); + bcm2835_dumpregs(host); + cmd->error = -EILSEQ; + bcm2835_finish_request(host); + return false; + } + + if (!cmd->data && cmd->busy_timeout > 9000) + timeout = DIV_ROUND_UP(cmd->busy_timeout, 1000) * HZ + HZ; + else + timeout = 10 * HZ; + schedule_delayed_work(&host->timeout_work, timeout); + + host->cmd = cmd; + + /* Clear any error flags */ + sdhsts = readl(host->ioaddr + SDHSTS); + if (sdhsts & SDHSTS_ERROR_MASK) + writel(sdhsts, host->ioaddr + SDHSTS); + + if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) { + dev_err(dev, "unsupported response type!\n"); + cmd->error = -EINVAL; + bcm2835_finish_request(host); + return false; + } + + bcm2835_prepare_data(host, cmd); + + writel(cmd->arg, host->ioaddr + SDARG); + + sdcmd = cmd->opcode & SDCMD_CMD_MASK; + + host->use_busy = false; + if (!(cmd->flags & MMC_RSP_PRESENT)) { + sdcmd |= SDCMD_NO_RESPONSE; + } else { + if (cmd->flags & MMC_RSP_136) + sdcmd |= SDCMD_LONG_RESPONSE; + if (cmd->flags & MMC_RSP_BUSY) { + sdcmd |= SDCMD_BUSYWAIT; + host->use_busy = true; + } + } + + if (cmd->data) { + if (cmd->data->flags & MMC_DATA_WRITE) + sdcmd |= SDCMD_WRITE_CMD; + if (cmd->data->flags & MMC_DATA_READ) + sdcmd |= SDCMD_READ_CMD; + } + + writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD); + + return true; +} + +static void bcm2835_transfer_complete(struct bcm2835_host *host) +{ + struct mmc_data *data; + + WARN_ON(!host->data_complete); + + data = host->data; + host->data = NULL; + + /* Need to send CMD12 if - + * a) open-ended multiblock transfer (no CMD23) + * b) error in multiblock transfer + */ + if (host->mrq->stop && (data->error || !host->use_sbc)) { + if (bcm2835_send_command(host, host->mrq->stop)) { + /* No busy, so poll for completion */ + if (!host->use_busy) + bcm2835_finish_command(host); + } + } else { + bcm2835_wait_transfer_complete(host); + bcm2835_finish_request(host); + } +} + +static void bcm2835_finish_data(struct bcm2835_host *host) +{ + struct device *dev = &host->pdev->dev; + struct mmc_data *data; + + data = host->data; + + host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN); + writel(host->hcfg, host->ioaddr + SDHCFG); + + data->bytes_xfered = data->error ? 0 : (data->blksz * data->blocks); + + host->data_complete = true; + + if (host->cmd) { + /* Data managed to finish before the + * command completed. Make sure we do + * things in the proper order. + */ + dev_dbg(dev, "Finished early - HSTS %08x\n", + readl(host->ioaddr + SDHSTS)); + } else { + bcm2835_transfer_complete(host); + } +} + +static void bcm2835_finish_command(struct bcm2835_host *host) +{ + struct device *dev = &host->pdev->dev; + struct mmc_command *cmd = host->cmd; + u32 sdcmd; + + sdcmd = bcm2835_read_wait_sdcmd(host, 100); + + /* Check for errors */ + if (sdcmd & SDCMD_NEW_FLAG) { + dev_err(dev, "command never completed.\n"); + bcm2835_dumpregs(host); + host->cmd->error = -EIO; + bcm2835_finish_request(host); + return; + } else if (sdcmd & SDCMD_FAIL_FLAG) { + u32 sdhsts = readl(host->ioaddr + SDHSTS); + + /* Clear the errors */ + writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS); + + if (!(sdhsts & SDHSTS_CRC7_ERROR) || + (host->cmd->opcode != MMC_SEND_OP_COND)) { + if (sdhsts & SDHSTS_CMD_TIME_OUT) { + host->cmd->error = -ETIMEDOUT; + } else { + dev_err(dev, "unexpected command %d error\n", + host->cmd->opcode); + bcm2835_dumpregs(host); + host->cmd->error = -EILSEQ; + } + bcm2835_finish_request(host); + return; + } + } + + if (cmd->flags & MMC_RSP_PRESENT) { + if (cmd->flags & MMC_RSP_136) { + int i; + + for (i = 0; i < 4; i++) { + cmd->resp[3 - i] = + readl(host->ioaddr + SDRSP0 + i * 4); + } + } else { + cmd->resp[0] = readl(host->ioaddr + SDRSP0); + } + } + + if (cmd == host->mrq->sbc) { + /* Finished CMD23, now send actual command. */ + host->cmd = NULL; + if (bcm2835_send_command(host, host->mrq->cmd)) { + if (host->data && host->dma_desc) + /* DMA transfer starts now, PIO starts + * after irq + */ + bcm2835_start_dma(host); + + if (!host->use_busy) + bcm2835_finish_command(host); + } + } else if (cmd == host->mrq->stop) { + /* Finished CMD12 */ + bcm2835_finish_request(host); + } else { + /* Processed actual command. */ + host->cmd = NULL; + if (!host->data) + bcm2835_finish_request(host); + else if (host->data_complete) + bcm2835_transfer_complete(host); + } +} + +static void bcm2835_timeout(struct work_struct *work) +{ + struct delayed_work *d = to_delayed_work(work); + struct bcm2835_host *host = + container_of(d, struct bcm2835_host, timeout_work); + struct device *dev = &host->pdev->dev; + + mutex_lock(&host->mutex); + + if (host->mrq) { + dev_err(dev, "timeout waiting for hardware interrupt.\n"); + bcm2835_dumpregs(host); + + if (host->data) { + host->data->error = -ETIMEDOUT; + bcm2835_finish_data(host); + } else { + if (host->cmd) + host->cmd->error = -ETIMEDOUT; + else + host->mrq->cmd->error = -ETIMEDOUT; + + bcm2835_finish_request(host); + } + } + + mutex_unlock(&host->mutex); +} + +static bool bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask) +{ + struct device *dev = &host->pdev->dev; + + if (!(intmask & SDHSTS_ERROR_MASK)) + return false; + + if (!host->cmd) + return true; + + dev_err(dev, "sdhost_busy_irq: intmask %08x\n", intmask); + if (intmask & SDHSTS_CRC7_ERROR) { + host->cmd->error = -EILSEQ; + } else if (intmask & (SDHSTS_CRC16_ERROR | + SDHSTS_FIFO_ERROR)) { + if (host->mrq->data) + host->mrq->data->error = -EILSEQ; + else + host->cmd->error = -EILSEQ; + } else if (intmask & SDHSTS_REW_TIME_OUT) { + if (host->mrq->data) + host->mrq->data->error = -ETIMEDOUT; + else + host->cmd->error = -ETIMEDOUT; + } else if (intmask & SDHSTS_CMD_TIME_OUT) { + host->cmd->error = -ETIMEDOUT; + } + bcm2835_dumpregs(host); + return true; +} + +static void bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask) +{ + if (!host->data) + return; + if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR)) + host->data->error = -EILSEQ; + if (intmask & SDHSTS_REW_TIME_OUT) + host->data->error = -ETIMEDOUT; +} + +static void bcm2835_busy_irq(struct bcm2835_host *host) +{ + if (WARN_ON(!host->cmd)) { + bcm2835_dumpregs(host); + return; + } + + if (WARN_ON(!host->use_busy)) { + bcm2835_dumpregs(host); + return; + } + host->use_busy = false; + + bcm2835_finish_command(host); +} + +static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask) +{ + /* There are no dedicated data/space available interrupt + * status bits, so it is necessary to use the single shared + * data/space available FIFO status bits. It is therefore not + * an error to get here when there is no data transfer in + * progress. + */ + if (!host->data) + return; + + bcm2835_check_data_error(host, intmask); + if (host->data->error) + goto finished; + + if (host->data->flags & MMC_DATA_WRITE) { + /* Use the block interrupt for writes after the first block */ + host->hcfg &= ~(SDHCFG_DATA_IRPT_EN); + host->hcfg |= SDHCFG_BLOCK_IRPT_EN; + writel(host->hcfg, host->ioaddr + SDHCFG); + bcm2835_transfer_pio(host); + } else { + bcm2835_transfer_pio(host); + host->blocks--; + if ((host->blocks == 0) || host->data->error) + goto finished; + } + return; + +finished: + host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN); + writel(host->hcfg, host->ioaddr + SDHCFG); +} + +static void bcm2835_data_threaded_irq(struct bcm2835_host *host) +{ + if (!host->data) + return; + if ((host->blocks == 0) || host->data->error) + bcm2835_finish_data(host); +} + +static void bcm2835_block_irq(struct bcm2835_host *host) +{ + if (WARN_ON(!host->data)) { + bcm2835_dumpregs(host); + return; + } + + if (!host->dma_desc) { + WARN_ON(!host->blocks); + if (host->data->error || (--host->blocks == 0)) + bcm2835_finish_data(host); + else + bcm2835_transfer_pio(host); + } else if (host->data->flags & MMC_DATA_WRITE) { + bcm2835_finish_data(host); + } +} + +static irqreturn_t bcm2835_irq(int irq, void *dev_id) +{ + irqreturn_t result = IRQ_NONE; + struct bcm2835_host *host = dev_id; + u32 intmask; + + spin_lock(&host->lock); + + intmask = readl(host->ioaddr + SDHSTS); + + writel(SDHSTS_BUSY_IRPT | + SDHSTS_BLOCK_IRPT | + SDHSTS_SDIO_IRPT | + SDHSTS_DATA_FLAG, + host->ioaddr + SDHSTS); + + if (intmask & SDHSTS_BLOCK_IRPT) { + bcm2835_check_data_error(host, intmask); + host->irq_block = true; + result = IRQ_WAKE_THREAD; + } + + if (intmask & SDHSTS_BUSY_IRPT) { + if (!bcm2835_check_cmd_error(host, intmask)) { + host->irq_busy = true; + result = IRQ_WAKE_THREAD; + } else { + result = IRQ_HANDLED; + } + } + + /* There is no true data interrupt status bit, so it is + * necessary to qualify the data flag with the interrupt + * enable bit. + */ + if ((intmask & SDHSTS_DATA_FLAG) && + (host->hcfg & SDHCFG_DATA_IRPT_EN)) { + bcm2835_data_irq(host, intmask); + host->irq_data = true; + result = IRQ_WAKE_THREAD; + } + + spin_unlock(&host->lock); + + return result; +} + +static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id) +{ + struct bcm2835_host *host = dev_id; + unsigned long flags; + bool block, busy, data; + + spin_lock_irqsave(&host->lock, flags); + + block = host->irq_block; + busy = host->irq_busy; + data = host->irq_data; + host->irq_block = false; + host->irq_busy = false; + host->irq_data = false; + + spin_unlock_irqrestore(&host->lock, flags); + + mutex_lock(&host->mutex); + + if (block) + bcm2835_block_irq(host); + if (busy) + bcm2835_busy_irq(host); + if (data) + bcm2835_data_threaded_irq(host); + + mutex_unlock(&host->mutex); + + return IRQ_HANDLED; +} + +static void bcm2835_dma_complete_work(struct work_struct *work) +{ + struct bcm2835_host *host = + container_of(work, struct bcm2835_host, dma_work); + struct mmc_data *data = host->data; + + mutex_lock(&host->mutex); + + if (host->dma_chan) { + dma_unmap_sg(host->dma_chan->device->dev, + data->sg, data->sg_len, + host->dma_dir); + + host->dma_chan = NULL; + } + + if (host->drain_words) { + unsigned long flags; + void *page; + u32 *buf; + + if (host->drain_offset & PAGE_MASK) { + host->drain_page += host->drain_offset >> PAGE_SHIFT; + host->drain_offset &= ~PAGE_MASK; + } + local_irq_save(flags); + page = kmap_atomic(host->drain_page); + buf = page + host->drain_offset; + + while (host->drain_words) { + u32 edm = readl(host->ioaddr + SDEDM); + + if ((edm >> 4) & 0x1f) + *(buf++) = readl(host->ioaddr + SDDATA); + host->drain_words--; + } + + kunmap_atomic(page); + local_irq_restore(flags); + } + + bcm2835_finish_data(host); + + mutex_unlock(&host->mutex); +} + +static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock) +{ + int div; + + /* The SDCDIV register has 11 bits, and holds (div - 2). But + * in data mode the max is 50MHz wihout a minimum, and only + * the bottom 3 bits are used. Since the switch over is + * automatic (unless we have marked the card as slow...), + * chosen values have to make sense in both modes. Ident mode + * must be 100-400KHz, so can range check the requested + * clock. CMD15 must be used to return to data mode, so this + * can be monitored. + * + * clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz + * 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz + * + * 623->400KHz/27.8MHz + * reset value (507)->491159/50MHz + * + * BUT, the 3-bit clock divisor in data mode is too small if + * the core clock is higher than 250MHz, so instead use the + * SLOW_CARD configuration bit to force the use of the ident + * clock divisor at all times. + */ + + if (clock < 100000) { + /* Can't stop the clock, but make it as slow as possible + * to show willing + */ + host->cdiv = SDCDIV_MAX_CDIV; + writel(host->cdiv, host->ioaddr + SDCDIV); + return; + } + + div = host->max_clk / clock; + if (div < 2) + div = 2; + if ((host->max_clk / div) > clock) + div++; + div -= 2; + + if (div > SDCDIV_MAX_CDIV) + div = SDCDIV_MAX_CDIV; + + clock = host->max_clk / (div + 2); + host->mmc->actual_clock = clock; + + /* Calibrate some delays */ + + host->ns_per_fifo_word = (1000000000 / clock) * + ((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32); + + host->cdiv = div; + writel(host->cdiv, host->ioaddr + SDCDIV); + + /* Set the timeout to 500ms */ + writel(host->mmc->actual_clock / 2, host->ioaddr + SDTOUT); +} + +static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) +{ + struct bcm2835_host *host = mmc_priv(mmc); + struct device *dev = &host->pdev->dev; + u32 edm, fsm; + + /* Reset the error statuses in case this is a retry */ + if (mrq->sbc) + mrq->sbc->error = 0; + if (mrq->cmd) + mrq->cmd->error = 0; + if (mrq->data) + mrq->data->error = 0; + if (mrq->stop) + mrq->stop->error = 0; + + if (mrq->data && !is_power_of_2(mrq->data->blksz)) { + dev_err(dev, "unsupported block size (%d bytes)\n", + mrq->data->blksz); + mrq->cmd->error = -EINVAL; + mmc_request_done(mmc, mrq); + return; + } + + if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD)) + bcm2835_prepare_dma(host, mrq->data); + + mutex_lock(&host->mutex); + + WARN_ON(host->mrq); + host->mrq = mrq; + + edm = readl(host->ioaddr + SDEDM); + fsm = edm & SDEDM_FSM_MASK; + + if ((fsm != SDEDM_FSM_IDENTMODE) && + (fsm != SDEDM_FSM_DATAMODE)) { + dev_err(dev, "previous command (%d) not complete (EDM %08x)\n", + readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK, + edm); + bcm2835_dumpregs(host); + mrq->cmd->error = -EILSEQ; + bcm2835_finish_request(host); + mutex_unlock(&host->mutex); + return; + } + + host->use_sbc = !!mrq->sbc && (host->mrq->data->flags & MMC_DATA_READ); + if (host->use_sbc) { + if (bcm2835_send_command(host, mrq->sbc)) { + if (!host->use_busy) + bcm2835_finish_command(host); + } + } else if (bcm2835_send_command(host, mrq->cmd)) { + if (host->data && host->dma_desc) { + /* DMA transfer starts now, PIO starts after irq */ + bcm2835_start_dma(host); + } + + if (!host->use_busy) + bcm2835_finish_command(host); + } + + mutex_unlock(&host->mutex); +} + +static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) +{ + struct bcm2835_host *host = mmc_priv(mmc); + + mutex_lock(&host->mutex); + + if (!ios->clock || ios->clock != host->clock) { + bcm2835_set_clock(host, ios->clock); + host->clock = ios->clock; + } + + /* set bus width */ + host->hcfg &= ~SDHCFG_WIDE_EXT_BUS; + if (ios->bus_width == MMC_BUS_WIDTH_4) + host->hcfg |= SDHCFG_WIDE_EXT_BUS; + + host->hcfg |= SDHCFG_WIDE_INT_BUS; + + /* Disable clever clock switching, to cope with fast core clocks */ + host->hcfg |= SDHCFG_SLOW_CARD; + + writel(host->hcfg, host->ioaddr + SDHCFG); + + mutex_unlock(&host->mutex); +} + +static struct mmc_host_ops bcm2835_ops = { + .request = bcm2835_request, + .set_ios = bcm2835_set_ios, + .hw_reset = bcm2835_reset, +}; + +static int bcm2835_add_host(struct bcm2835_host *host) +{ + struct mmc_host *mmc = host->mmc; + struct device *dev = &host->pdev->dev; + char pio_limit_string[20]; + int ret; + + mmc->f_max = host->max_clk; + mmc->f_min = host->max_clk / SDCDIV_MAX_CDIV; + + mmc->max_busy_timeout = ~0 / (mmc->f_max / 1000); + + dev_dbg(dev, "f_max %d, f_min %d, max_busy_timeout %d\n", + mmc->f_max, mmc->f_min, mmc->max_busy_timeout); + + /* host controller capabilities */ + mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED | + MMC_CAP_NEEDS_POLL | MMC_CAP_HW_RESET | MMC_CAP_ERASE | + MMC_CAP_CMD23; + + spin_lock_init(&host->lock); + mutex_init(&host->mutex); + + if (IS_ERR_OR_NULL(host->dma_chan_rxtx)) { + dev_warn(dev, "unable to initialise DMA channel. Falling back to PIO\n"); + host->use_dma = false; + } else { + host->use_dma = true; + + host->dma_cfg_tx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + host->dma_cfg_tx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + host->dma_cfg_tx.slave_id = 13; /* DREQ channel */ + host->dma_cfg_tx.direction = DMA_MEM_TO_DEV; + host->dma_cfg_tx.src_addr = 0; + host->dma_cfg_tx.dst_addr = host->phys_addr + SDDATA; + + host->dma_cfg_rx.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + host->dma_cfg_rx.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + host->dma_cfg_rx.slave_id = 13; /* DREQ channel */ + host->dma_cfg_rx.direction = DMA_DEV_TO_MEM; + host->dma_cfg_rx.src_addr = host->phys_addr + SDDATA; + host->dma_cfg_rx.dst_addr = 0; + + if (dmaengine_slave_config(host->dma_chan_rxtx, + &host->dma_cfg_tx) != 0 || + dmaengine_slave_config(host->dma_chan_rxtx, + &host->dma_cfg_rx) != 0) + host->use_dma = false; + } + + mmc->max_segs = 128; + mmc->max_req_size = 524288; + mmc->max_seg_size = mmc->max_req_size; + mmc->max_blk_size = 1024; + mmc->max_blk_count = 65535; + + /* report supported voltage ranges */ + mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; + + INIT_WORK(&host->dma_work, bcm2835_dma_complete_work); + INIT_DELAYED_WORK(&host->timeout_work, bcm2835_timeout); + + /* Set interrupt enables */ + host->hcfg = SDHCFG_BUSY_IRPT_EN; + + bcm2835_reset_internal(host); + + ret = request_threaded_irq(host->irq, bcm2835_irq, + bcm2835_threaded_irq, + 0, mmc_hostname(mmc), host); + if (ret) { + dev_err(dev, "failed to request IRQ %d: %d\n", host->irq, ret); + return ret; + } + + ret = mmc_add_host(mmc); + if (ret) { + free_irq(host->irq, host); + return ret; + } + + pio_limit_string[0] = '\0'; + if (host->use_dma && (PIO_THRESHOLD > 0)) + sprintf(pio_limit_string, " (>%d)", PIO_THRESHOLD); + dev_info(dev, "loaded - DMA %s%s\n", + host->use_dma ? "enabled" : "disabled", pio_limit_string); + + return 0; +} + +static int bcm2835_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct clk *clk; + struct resource *iomem; + struct bcm2835_host *host; + struct mmc_host *mmc; + const __be32 *regaddr_p; + int ret; + + dev_dbg(dev, "%s\n", __func__); + mmc = mmc_alloc_host(sizeof(*host), dev); + if (!mmc) + return -ENOMEM; + + mmc->ops = &bcm2835_ops; + host = mmc_priv(mmc); + host->mmc = mmc; + host->pdev = pdev; + spin_lock_init(&host->lock); + + iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + host->ioaddr = devm_ioremap_resource(dev, iomem); + if (IS_ERR(host->ioaddr)) { + ret = PTR_ERR(host->ioaddr); + goto err; + } + + /* Parse OF address directly to get the physical address for + * DMA to our registers. + */ + regaddr_p = of_get_address(pdev->dev.of_node, 0, NULL, NULL); + if (!regaddr_p) { + dev_err(dev, "Can't get phys address\n"); + ret = -EINVAL; + goto err; + } + + host->phys_addr = be32_to_cpup(regaddr_p); + + host->dma_chan = NULL; + host->dma_desc = NULL; + + host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx"); + + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) { + ret = PTR_ERR(clk); + if (ret != -EPROBE_DEFER) + dev_err(dev, "could not get clk: %d\n", ret); + goto err; + } + + host->max_clk = clk_get_rate(clk); + + host->irq = platform_get_irq(pdev, 0); + if (host->irq <= 0) { + dev_err(dev, "get IRQ failed\n"); + ret = -EINVAL; + goto err; + } + + ret = mmc_of_parse(mmc); + if (ret) + goto err; + + ret = bcm2835_add_host(host); + if (ret) + goto err; + + platform_set_drvdata(pdev, host); + + dev_dbg(dev, "%s -> OK\n", __func__); + + return 0; + +err: + dev_dbg(dev, "%s -> err %d\n", __func__, ret); + mmc_free_host(mmc); + + return ret; +} + +static int bcm2835_remove(struct platform_device *pdev) +{ + struct bcm2835_host *host = platform_get_drvdata(pdev); + + mmc_remove_host(host->mmc); + + writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD); + + free_irq(host->irq, host); + + cancel_work_sync(&host->dma_work); + cancel_delayed_work_sync(&host->timeout_work); + + mmc_free_host(host->mmc); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static const struct of_device_id bcm2835_match[] = { + { .compatible = "brcm,bcm2835-sdhost" }, + { } +}; +MODULE_DEVICE_TABLE(of, bcm2835_match); + +static struct platform_driver bcm2835_driver = { + .probe = bcm2835_probe, + .remove = bcm2835_remove, + .driver = { + .name = "sdhost-bcm2835", + .of_match_table = bcm2835_match, + }, +}; +module_platform_driver(bcm2835_driver); + +MODULE_ALIAS("platform:sdhost-bcm2835"); +MODULE_DESCRIPTION("BCM2835 SDHost driver"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Phil Elwell"); |