#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/blkdev.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/mmc/host.h>
#include <linux/mmc/sd.h>
#include <linux/sched.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/clk.h>
#include <linux/bitops.h>
#include <linux/of_dma.h>
#include <linux/spinlock.h>
#define REG_COMMAND 0
#define REG_ARGUMENT 4
#define REG_RESPONSE0 8
#define REG_RESPONSE1 12
#define REG_RESPONSE2 16
#define REG_RESPONSE3 20
#define REG_RESPONSE_COMMAND 24
#define REG_DATA_CONTROL 28
#define REG_DATA_TIMER 32
#define REG_DATA_LENGTH 36
#define REG_STATUS 40
#define REG_CLEAR 44
#define REG_INTERRUPT_MASK 48
#define REG_POWER_CONTROL 52
#define REG_CLOCK_CONTROL 56
#define REG_BUS_WIDTH 60
#define REG_DATA_WINDOW 64
#define REG_FEATURE 68
#define REG_REVISION 72
#define CMD_SDC_RESET BIT(10)
#define CMD_EN BIT(9)
#define CMD_APP_CMD BIT(8)
#define CMD_LONG_RSP BIT(7)
#define CMD_NEED_RSP BIT(6)
#define CMD_IDX_MASK 0x3f
#define RSP_CMD_APP BIT(6)
#define RSP_CMD_IDX_MASK 0x3f
#define DCR_DATA_FIFO_RESET BIT(8)
#define DCR_DATA_THRES BIT(7)
#define DCR_DATA_EN BIT(6)
#define DCR_DMA_EN BIT(5)
#define DCR_DATA_WRITE BIT(4)
#define DCR_BLK_SIZE 0x0f
#define DATA_LEN_MASK 0xffffff
#define WRITE_PROT BIT(12)
#define CARD_DETECT BIT(11)
#define CARD_CHANGE BIT(10)
#define FIFO_ORUN BIT(9)
#define FIFO_URUN BIT(8)
#define DATA_END BIT(7)
#define CMD_SENT BIT(6)
#define DATA_CRC_OK BIT(5)
#define RSP_CRC_OK BIT(4)
#define DATA_TIMEOUT BIT(3)
#define RSP_TIMEOUT BIT(2)
#define DATA_CRC_FAIL BIT(1)
#define RSP_CRC_FAIL BIT(0)
#define MASK_RSP (RSP_TIMEOUT | RSP_CRC_FAIL | \
RSP_CRC_OK | CARD_DETECT | CMD_SENT)
#define MASK_DATA (DATA_CRC_OK | DATA_END | \
DATA_CRC_FAIL | DATA_TIMEOUT)
#define MASK_INTR_PIO (FIFO_URUN | FIFO_ORUN | CARD_CHANGE)
#define SD_POWER_ON BIT(4)
#define SD_POWER_MASK 0x0f
#define CLK_HISPD BIT(9)
#define CLK_OFF BIT(8)
#define CLK_SD BIT(7)
#define CLK_DIV_MASK 0x7f
#define BUS_WIDTH_4_SUPPORT BIT(3)
#define BUS_WIDTH_4 BIT(2)
#define BUS_WIDTH_1 BIT(0)
#define MMC_VDD_360 23
#define MIN_POWER (MMC_VDD_360 - SD_POWER_MASK)
#define MAX_RETRIES 500000
struct moxart_host {
spinlock_t lock;
void __iomem *base;
phys_addr_t reg_phys;
struct dma_chan *dma_chan_tx;
struct dma_chan *dma_chan_rx;
struct dma_async_tx_descriptor *tx_desc;
struct mmc_host *mmc;
struct mmc_request *mrq;
struct scatterlist *cur_sg;
struct completion dma_complete;
struct completion pio_complete;
u32 num_sg;
u32 data_remain;
u32 data_len;
u32 fifo_width;
u32 timeout;
u32 rate;
long sysclk;
bool have_dma;
bool is_removed;
};
static inline void moxart_init_sg(struct moxart_host *host,
struct mmc_data *data)
{
host->cur_sg = data->sg;
host->num_sg = data->sg_len;
host->data_remain = host->cur_sg->length;
if (host->data_remain > host->data_len)
host->data_remain = host->data_len;
}
static inline int moxart_next_sg(struct moxart_host *host)
{
int remain;
struct mmc_data *data = host->mrq->cmd->data;
host->cur_sg++;
host->num_sg--;
if (host->num_sg > 0) {
host->data_remain = host->cur_sg->length;
remain = host->data_len - data->bytes_xfered;
if (remain > 0 && remain < host->data_remain)
host->data_remain = remain;
}
return host->num_sg;
}
static int moxart_wait_for_status(struct moxart_host *host,
u32 mask, u32 *status)
{
int ret = -ETIMEDOUT;
u32 i;
for (i = 0; i < MAX_RETRIES; i++) {
*status = readl(host->base + REG_STATUS);
if (!(*status & mask)) {
udelay(5);
continue;
}
writel(*status & mask, host->base + REG_CLEAR);
ret = 0;
break;
}
if (ret)
dev_err(mmc_dev(host->mmc), "timed out waiting for status\n");
return ret;
}
static void moxart_send_command(struct moxart_host *host,
struct mmc_command *cmd)
{
u32 status, cmdctrl;
writel(RSP_TIMEOUT | RSP_CRC_OK |
RSP_CRC_FAIL | CMD_SENT, host->base + REG_CLEAR);
writel(cmd->arg, host->base + REG_ARGUMENT);
cmdctrl = cmd->opcode & CMD_IDX_MASK;
if (cmdctrl == SD_APP_SET_BUS_WIDTH || cmdctrl == SD_APP_OP_COND ||
cmdctrl == SD_APP_SEND_SCR || cmdctrl == SD_APP_SD_STATUS ||
cmdctrl == SD_APP_SEND_NUM_WR_BLKS)
cmdctrl |= CMD_APP_CMD;
if (cmd->flags & MMC_RSP_PRESENT)
cmdctrl |= CMD_NEED_RSP;
if (cmd->flags & MMC_RSP_136)
cmdctrl |= CMD_LONG_RSP;
writel(cmdctrl | CMD_EN, host->base + REG_COMMAND);
if (moxart_wait_for_status(host, MASK_RSP, &status) == -ETIMEDOUT)
cmd->error = -ETIMEDOUT;
if (status & RSP_TIMEOUT) {
cmd->error = -ETIMEDOUT;
return;
}
if (status & RSP_CRC_FAIL) {
cmd->error = -EIO;
return;
}
if (status & RSP_CRC_OK) {
if (cmd->flags & MMC_RSP_136) {
cmd->resp[3] = readl(host->base + REG_RESPONSE0);
cmd->resp[2] = readl(host->base + REG_RESPONSE1);
cmd->resp[1] = readl(host->base + REG_RESPONSE2);
cmd->resp[0] = readl(host->base + REG_RESPONSE3);
} else {
cmd->resp[0] = readl(host->base + REG_RESPONSE0);
}
}
}
static void moxart_dma_complete(void *param)
{
struct moxart_host *host = param;
complete(&host->dma_complete);
}
static bool moxart_use_dma(struct moxart_host *host)
{
return (host->data_len > host->fifo_width) && host->have_dma;
}
static void moxart_transfer_dma(struct mmc_data *data, struct moxart_host *host)
{
u32 len, dir_slave;
struct dma_async_tx_descriptor *desc = NULL;
struct dma_chan *dma_chan;
if (host->data_len == data->bytes_xfered)
return;
if (data->flags & MMC_DATA_WRITE) {
dma_chan = host->dma_chan_tx;
dir_slave = DMA_MEM_TO_DEV;
} else {
dma_chan = host->dma_chan_rx;
dir_slave = DMA_DEV_TO_MEM;
}
len = dma_map_sg(dma_chan->device->dev, data->sg,
data->sg_len, mmc_get_dma_dir(data));
if (len > 0) {
desc = dmaengine_prep_slave_sg(dma_chan, 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) {
host->tx_desc = desc;
desc->callback = moxart_dma_complete;
desc->callback_param = host;
dmaengine_submit(desc);
dma_async_issue_pending(dma_chan);
}
wait_for_completion_interruptible_timeout(&host->dma_complete,
host->timeout);
data->bytes_xfered = host->data_len;
dma_unmap_sg(dma_chan->device->dev,
data->sg, data->sg_len,
mmc_get_dma_dir(data));
}
static void moxart_transfer_pio(struct moxart_host *host)
{
struct mmc_data *data = host->mrq->cmd->data;
u32 *sgp, len = 0, remain, status;
if (host->data_len == data->bytes_xfered)
return;
sgp = sg_virt(host->cur_sg);
remain = host->data_remain;
if (data->flags & MMC_DATA_WRITE) {
while (remain > 0) {
if (moxart_wait_for_status(host, FIFO_URUN, &status)
== -ETIMEDOUT) {
data->error = -ETIMEDOUT;
complete(&host->pio_complete);
return;
}
for (len = 0; len < remain && len < host->fifo_width;) {
iowrite32(*sgp, host->base + REG_DATA_WINDOW);
sgp++;
len += 4;
}
remain -= len;
}
} else {
while (remain > 0) {
if (moxart_wait_for_status(host, FIFO_ORUN, &status)
== -ETIMEDOUT) {
data->error = -ETIMEDOUT;
complete(&host->pio_complete);
return;
}
for (len = 0; len < remain && len < host->fifo_width;) {
*sgp = ioread32(host->base + REG_DATA_WINDOW);
sgp++;
len += 4;
}
remain -= len;
}
}
data->bytes_xfered += host->data_remain - remain;
host->data_remain = remain;
if (host->data_len != data->bytes_xfered)
moxart_next_sg(host);
else
complete(&host->pio_complete);
}
static void moxart_prepare_data(struct moxart_host *host)
{
struct mmc_data *data = host->mrq->cmd->data;
u32 datactrl;
int blksz_bits;
if (!data)
return;
host->data_len = data->blocks * data->blksz;
blksz_bits = ffs(data->blksz) - 1;
BUG_ON(1 << blksz_bits != data->blksz);
moxart_init_sg(host, data);
datactrl = DCR_DATA_EN | (blksz_bits & DCR_BLK_SIZE);
if (data->flags & MMC_DATA_WRITE)
datactrl |= DCR_DATA_WRITE;
if (moxart_use_dma(host))
datactrl |= DCR_DMA_EN;
writel(DCR_DATA_FIFO_RESET, host->base + REG_DATA_CONTROL);
writel(MASK_DATA | FIFO_URUN | FIFO_ORUN, host->base + REG_CLEAR);
writel(host->rate, host->base + REG_DATA_TIMER);
writel(host->data_len, host->base + REG_DATA_LENGTH);
writel(datactrl, host->base + REG_DATA_CONTROL);
}
static void moxart_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
struct moxart_host *host = mmc_priv(mmc);
unsigned long flags;
u32 status;
spin_lock_irqsave(&host->lock, flags);
init_completion(&host->dma_complete);
init_completion(&host->pio_complete);
host->mrq = mrq;
if (readl(host->base + REG_STATUS) & CARD_DETECT) {
mrq->cmd->error = -ETIMEDOUT;
goto request_done;
}
moxart_prepare_data(host);
moxart_send_command(host, host->mrq->cmd);
if (mrq->cmd->data) {
if (moxart_use_dma(host)) {
writel(CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
spin_unlock_irqrestore(&host->lock, flags);
moxart_transfer_dma(mrq->cmd->data, host);
spin_lock_irqsave(&host->lock, flags);
} else {
writel(MASK_INTR_PIO, host->base + REG_INTERRUPT_MASK);
spin_unlock_irqrestore(&host->lock, flags);
wait_for_completion_interruptible_timeout(&host->pio_complete,
host->timeout);
spin_lock_irqsave(&host->lock, flags);
}
if (host->is_removed) {
dev_err(mmc_dev(host->mmc), "card removed\n");
mrq->cmd->error = -ETIMEDOUT;
goto request_done;
}
if (moxart_wait_for_status(host, MASK_DATA, &status)
== -ETIMEDOUT) {
mrq->cmd->data->error = -ETIMEDOUT;
goto request_done;
}
if (status & DATA_CRC_FAIL)
mrq->cmd->data->error = -ETIMEDOUT;
if (mrq->cmd->data->stop)
moxart_send_command(host, mrq->cmd->data->stop);
}
request_done:
spin_unlock_irqrestore(&host->lock, flags);
mmc_request_done(host->mmc, mrq);
}
static irqreturn_t moxart_irq(int irq, void *devid)
{
struct moxart_host *host = (struct moxart_host *)devid;
u32 status;
spin_lock(&host->lock);
status = readl(host->base + REG_STATUS);
if (status & CARD_CHANGE) {
host->is_removed = status & CARD_DETECT;
if (host->is_removed && host->have_dma) {
dmaengine_terminate_all(host->dma_chan_tx);
dmaengine_terminate_all(host->dma_chan_rx);
}
host->mrq = NULL;
writel(MASK_INTR_PIO, host->base + REG_CLEAR);
writel(CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
mmc_detect_change(host->mmc, 0);
}
if (status & (FIFO_ORUN | FIFO_URUN) && host->mrq)
moxart_transfer_pio(host);
spin_unlock(&host->lock);
return IRQ_HANDLED;
}
static void moxart_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct moxart_host *host = mmc_priv(mmc);
unsigned long flags;
u8 power, div;
u32 ctrl;
spin_lock_irqsave(&host->lock, flags);
if (ios->clock) {
for (div = 0; div < CLK_DIV_MASK; ++div) {
if (ios->clock >= host->sysclk / (2 * (div + 1)))
break;
}
ctrl = CLK_SD | div;
host->rate = host->sysclk / (2 * (div + 1));
if (host->rate > host->sysclk)
ctrl |= CLK_HISPD;
writel(ctrl, host->base + REG_CLOCK_CONTROL);
}
if (ios->power_mode == MMC_POWER_OFF) {
writel(readl(host->base + REG_POWER_CONTROL) & ~SD_POWER_ON,
host->base + REG_POWER_CONTROL);
} else {
if (ios->vdd < MIN_POWER)
power = 0;
else
power = ios->vdd - MIN_POWER;
writel(SD_POWER_ON | (u32) power,
host->base + REG_POWER_CONTROL);
}
switch (ios->bus_width) {
case MMC_BUS_WIDTH_4:
writel(BUS_WIDTH_4, host->base + REG_BUS_WIDTH);
break;
default:
writel(BUS_WIDTH_1, host->base + REG_BUS_WIDTH);
break;
}
spin_unlock_irqrestore(&host->lock, flags);
}
static int moxart_get_ro(struct mmc_host *mmc)
{
struct moxart_host *host = mmc_priv(mmc);
return !!(readl(host->base + REG_STATUS) & WRITE_PROT);
}
static const struct mmc_host_ops moxart_ops = {
.request = moxart_request,
.set_ios = moxart_set_ios,
.get_ro = moxart_get_ro,
};
static int moxart_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node;
struct resource res_mmc;
struct mmc_host *mmc;
struct moxart_host *host = NULL;
struct dma_slave_config cfg;
struct clk *clk;
void __iomem *reg_mmc;
int irq, ret;
u32 i;
mmc = devm_mmc_alloc_host(dev, sizeof(*host));
if (!mmc) {
dev_err(dev, "devm_mmc_alloc_host failed\n");
return -ENOMEM;
}
ret = of_address_to_resource(node, 0, &res_mmc);
if (ret)
return dev_err_probe(dev, ret,
"of_address_to_resource failed\n");
irq = irq_of_parse_and_map(node, 0);
if (irq <= 0)
return dev_err_probe(dev, -EINVAL,
"irq_of_parse_and_map failed\n");
clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk))
return PTR_ERR(clk);
reg_mmc = devm_ioremap_resource(dev, &res_mmc);
if (IS_ERR(reg_mmc))
return PTR_ERR(reg_mmc);
ret = mmc_of_parse(mmc);
if (ret)
return ret;
host = mmc_priv(mmc);
host->mmc = mmc;
host->base = reg_mmc;
host->reg_phys = res_mmc.start;
host->timeout = msecs_to_jiffies(1000);
host->sysclk = clk_get_rate(clk);
host->fifo_width = readl(host->base + REG_FEATURE) << 2;
host->dma_chan_tx = dma_request_chan(dev, "tx");
host->dma_chan_rx = dma_request_chan(dev, "rx");
spin_lock_init(&host->lock);
mmc->ops = &moxart_ops;
mmc->f_max = DIV_ROUND_CLOSEST(host->sysclk, 2);
mmc->f_min = DIV_ROUND_CLOSEST(host->sysclk, CLK_DIV_MASK * 2);
mmc->ocr_avail = 0xffff00;
mmc->max_blk_size = 2048;
mmc->max_req_size = DATA_LEN_MASK;
mmc->max_blk_count = mmc->max_req_size / 512;
if (IS_ERR(host->dma_chan_tx) || IS_ERR(host->dma_chan_rx)) {
if (PTR_ERR(host->dma_chan_tx) == -EPROBE_DEFER ||
PTR_ERR(host->dma_chan_rx) == -EPROBE_DEFER) {
ret = -EPROBE_DEFER;
goto out;
}
if (!IS_ERR(host->dma_chan_tx)) {
dma_release_channel(host->dma_chan_tx);
host->dma_chan_tx = NULL;
}
if (!IS_ERR(host->dma_chan_rx)) {
dma_release_channel(host->dma_chan_rx);
host->dma_chan_rx = NULL;
}
dev_dbg(dev, "PIO mode transfer enabled\n");
host->have_dma = false;
mmc->max_seg_size = mmc->max_req_size;
} else {
dev_dbg(dev, "DMA channels found (%p,%p)\n",
host->dma_chan_tx, host->dma_chan_rx);
host->have_dma = true;
memset(&cfg, 0, sizeof(cfg));
cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
cfg.direction = DMA_MEM_TO_DEV;
cfg.src_addr = 0;
cfg.dst_addr = host->reg_phys + REG_DATA_WINDOW;
dmaengine_slave_config(host->dma_chan_tx, &cfg);
cfg.direction = DMA_DEV_TO_MEM;
cfg.src_addr = host->reg_phys + REG_DATA_WINDOW;
cfg.dst_addr = 0;
dmaengine_slave_config(host->dma_chan_rx, &cfg);
mmc->max_seg_size = min3(mmc->max_req_size,
dma_get_max_seg_size(host->dma_chan_rx->device->dev),
dma_get_max_seg_size(host->dma_chan_tx->device->dev));
}
if (readl(host->base + REG_BUS_WIDTH) & BUS_WIDTH_4_SUPPORT)
mmc->caps |= MMC_CAP_4_BIT_DATA;
writel(0, host->base + REG_INTERRUPT_MASK);
writel(CMD_SDC_RESET, host->base + REG_COMMAND);
for (i = 0; i < MAX_RETRIES; i++) {
if (!(readl(host->base + REG_COMMAND) & CMD_SDC_RESET))
break;
udelay(5);
}
ret = devm_request_irq(dev, irq, moxart_irq, 0, "moxart-mmc", host);
if (ret)
goto out;
dev_set_drvdata(dev, mmc);
ret = mmc_add_host(mmc);
if (ret)
goto out;
dev_dbg(dev, "IRQ=%d, FIFO is %d bytes\n", irq, host->fifo_width);
return 0;
out:
if (!IS_ERR_OR_NULL(host->dma_chan_tx))
dma_release_channel(host->dma_chan_tx);
if (!IS_ERR_OR_NULL(host->dma_chan_rx))
dma_release_channel(host->dma_chan_rx);
return ret;
}
static void moxart_remove(struct platform_device *pdev)
{
struct mmc_host *mmc = dev_get_drvdata(&pdev->dev);
struct moxart_host *host = mmc_priv(mmc);
if (!IS_ERR_OR_NULL(host->dma_chan_tx))
dma_release_channel(host->dma_chan_tx);
if (!IS_ERR_OR_NULL(host->dma_chan_rx))
dma_release_channel(host->dma_chan_rx);
mmc_remove_host(mmc);
writel(0, host->base + REG_INTERRUPT_MASK);
writel(0, host->base + REG_POWER_CONTROL);
writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
host->base + REG_CLOCK_CONTROL);
}
static const struct of_device_id moxart_mmc_match[] = {
{ .compatible = "moxa,moxart-mmc" },
{ .compatible = "faraday,ftsdc010" },
{ }
};
MODULE_DEVICE_TABLE(of, moxart_mmc_match);
static struct platform_driver moxart_mmc_driver = {
.probe = moxart_probe,
.remove = moxart_remove,
.driver = {
.name = "mmc-moxart",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.of_match_table = moxart_mmc_match,
},
};
module_platform_driver(moxart_mmc_driver);
MODULE_ALIAS("platform:mmc-moxart");
MODULE_DESCRIPTION("MOXA ART MMC driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
