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linux/drivers/mmc/host/bcm2835.c

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// SPDX-License-Identifier: GPL-2.0
/*
* 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
*/
#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 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);
host->dma_chan = NULL;
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 sg_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);
sg_len = dma_map_sg(dma_chan->device->dev, data->sg, data->sg_len,
dir_data);
if (!sg_len)
return;
desc = dmaengine_prep_slave_sg(dma_chan, data->sg, sg_len, dir_slave,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
dma_unmap_sg(dma_chan->device->dev, data->sg, sg_len, dir_data);
return;
}
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(mmc_from_priv(host), 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)) {
u32 edm, fsm;
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;
}
edm = readl(host->ioaddr + SDEDM);
fsm = edm & SDEDM_FSM_MASK;
if (fsm == SDEDM_FSM_READWAIT ||
fsm == SDEDM_FSM_WRITESTART1)
/* Kick the FSM out of its wait */
writel(edm | SDEDM_FORCE_DATA_MODE,
host->ioaddr + SDEDM);
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);
bcm2835_reset(mmc_from_priv(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;
mutex_lock(&host->mutex);
data = host->data;
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)
{
struct mmc_host *mmc = mmc_from_priv(host);
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);
mmc->actual_clock = clock;
/* Calibrate some delays */
host->ns_per_fifo_word = (1000000000 / clock) *
((mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
host->cdiv = div;
writel(host->cdiv, host->ioaddr + SDCDIV);
/* Set the timeout to 500ms */
writel(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);
if (mrq->cmd)
mrq->cmd->error = -EINVAL;
mmc_request_done(mmc, mrq);
return;
}
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);
if (mrq->cmd)
mrq->cmd->error = -EILSEQ;
bcm2835_finish_request(host);
mutex_unlock(&host->mutex);
return;
}
if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD))
bcm2835_prepare_dma(host, mrq->data);
host->use_sbc = !!mrq->sbc && host->mrq->data &&
(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 (mrq->cmd && 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 const 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 = mmc_from_priv(host);
struct device *dev = &host->pdev->dev;
char pio_limit_string[20];
int ret;
if (!mmc->f_max || mmc->f_max > host->max_clk)
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_CMD23;
spin_lock_init(&host->lock);
mutex_init(&host->mutex);
if (!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 = min_t(size_t, 524288, dma_max_mapping_size(dev));
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 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->pdev = pdev;
spin_lock_init(&host->lock);
host->ioaddr = devm_platform_ioremap_resource(pdev, 0);
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_chan(dev, "rx-tx");
if (IS_ERR(host->dma_chan_rxtx)) {
ret = PTR_ERR(host->dma_chan_rxtx);
host->dma_chan_rxtx = NULL;
if (ret == -EPROBE_DEFER)
goto err;
/* Ignore errors to fall back to PIO mode */
}
clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk)) {
ret = dev_err_probe(dev, PTR_ERR(clk), "could not get clk\n");
goto err;
}
host->max_clk = clk_get_rate(clk);
host->irq = platform_get_irq(pdev, 0);
if (host->irq <= 0) {
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);
if (host->dma_chan_rxtx)
dma_release_channel(host->dma_chan_rxtx);
mmc_free_host(mmc);
return ret;
}
static int bcm2835_remove(struct platform_device *pdev)
{
struct bcm2835_host *host = platform_get_drvdata(pdev);
struct mmc_host *mmc = mmc_from_priv(host);
mmc_remove_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);
if (host->dma_chan_rxtx)
dma_release_channel(host->dma_chan_rxtx);
mmc_free_host(mmc);
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",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.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");
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