tifm_sd.c

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/*
 *  tifm_sd.c - TI FlashMedia driver
 *
 *  Copyright (C) 2006 Alex Dubov <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Special thanks to Brad Campbell for extensive testing of this driver.
 *
 */


#include <linux/tifm.h>
#include <linux/mmc/host.h>
#include <linux/highmem.h>
#include <linux/scatterlist.h>
#include <asm/io.h>

#define DRIVER_NAME "tifm_sd"
#define DRIVER_VERSION "0.8"

static int no_dma = 0;
static int fixed_timeout = 0;
module_param(no_dma, bool, 0644);
module_param(fixed_timeout, bool, 0644);

/* Constants here are mostly from OMAP5912 datasheet */
#define TIFM_MMCSD_RESET      0x0002
#define TIFM_MMCSD_CLKMASK    0x03ff
#define TIFM_MMCSD_POWER      0x0800
#define TIFM_MMCSD_4BBUS      0x8000
#define TIFM_MMCSD_RXDE       0x8000   /* rx dma enable */
#define TIFM_MMCSD_TXDE       0x0080   /* tx dma enable */
#define TIFM_MMCSD_BUFINT     0x0c00   /* set bits: AE, AF */
#define TIFM_MMCSD_DPE        0x0020   /* data timeout counted in kilocycles */
#define TIFM_MMCSD_INAB       0x0080   /* abort / initialize command */
#define TIFM_MMCSD_READ       0x8000

#define TIFM_MMCSD_ERRMASK    0x01e0   /* set bits: CCRC, CTO, DCRC, DTO */
#define TIFM_MMCSD_EOC        0x0001   /* end of command phase  */
#define TIFM_MMCSD_CD         0x0002   /* card detect           */
#define TIFM_MMCSD_CB         0x0004   /* card enter busy state */
#define TIFM_MMCSD_BRS        0x0008   /* block received/sent   */
#define TIFM_MMCSD_EOFB       0x0010   /* card exit busy state  */
#define TIFM_MMCSD_DTO        0x0020   /* data time-out         */
#define TIFM_MMCSD_DCRC       0x0040   /* data crc error        */
#define TIFM_MMCSD_CTO        0x0080   /* command time-out      */
#define TIFM_MMCSD_CCRC       0x0100   /* command crc error     */
#define TIFM_MMCSD_AF         0x0400   /* fifo almost full      */
#define TIFM_MMCSD_AE         0x0800   /* fifo almost empty     */
#define TIFM_MMCSD_OCRB       0x1000   /* OCR busy              */
#define TIFM_MMCSD_CIRQ       0x2000   /* card irq (cmd40/sdio) */
#define TIFM_MMCSD_CERR       0x4000   /* card status error     */

#define TIFM_MMCSD_ODTO       0x0040   /* open drain / extended timeout */
#define TIFM_MMCSD_CARD_RO    0x0200   /* card is read-only     */

#define TIFM_MMCSD_FIFO_SIZE  0x0020

#define TIFM_MMCSD_RSP_R0     0x0000
#define TIFM_MMCSD_RSP_R1     0x0100
#define TIFM_MMCSD_RSP_R2     0x0200
#define TIFM_MMCSD_RSP_R3     0x0300
#define TIFM_MMCSD_RSP_R4     0x0400
#define TIFM_MMCSD_RSP_R5     0x0500
#define TIFM_MMCSD_RSP_R6     0x0600

#define TIFM_MMCSD_RSP_BUSY   0x0800

#define TIFM_MMCSD_CMD_BC     0x0000
#define TIFM_MMCSD_CMD_BCR    0x1000
#define TIFM_MMCSD_CMD_AC     0x2000
#define TIFM_MMCSD_CMD_ADTC   0x3000

#define TIFM_MMCSD_MAX_BLOCK_SIZE  0x0800UL

enum {
	CMD_READY    = 0x0001,
	FIFO_READY   = 0x0002,
	BRS_READY    = 0x0004,
	SCMD_ACTIVE  = 0x0008,
	SCMD_READY   = 0x0010,
	CARD_BUSY    = 0x0020,
	DATA_CARRY   = 0x0040
};

struct tifm_sd {
	struct tifm_dev       *dev;

	unsigned short        eject:1,
			      open_drain:1,
			      no_dma:1;
	unsigned short        cmd_flags;

	unsigned int          clk_freq;
	unsigned int          clk_div;
	unsigned long         timeout_jiffies;

	struct tasklet_struct finish_tasklet;
	struct timer_list     timer;
	struct mmc_request    *req;

	int                   sg_len;
	int                   sg_pos;
	unsigned int          block_pos;
	struct scatterlist    bounce_buf;
	unsigned char         bounce_buf_data[TIFM_MMCSD_MAX_BLOCK_SIZE];
};

/* for some reason, host won't respond correctly to readw/writew */
static void tifm_sd_read_fifo(struct tifm_sd *host, struct page *pg,
			      unsigned int off, unsigned int cnt)
{
	struct tifm_dev *sock = host->dev;
	unsigned char *buf;
	unsigned int pos = 0, val;

	buf = kmap_atomic(pg, KM_BIO_DST_IRQ) + off;
	if (host->cmd_flags & DATA_CARRY) {
		buf[pos++] = host->bounce_buf_data[0];
		host->cmd_flags &= ~DATA_CARRY;
	}

	while (pos < cnt) {
		val = readl(sock->addr + SOCK_MMCSD_DATA);
		buf[pos++] = val & 0xff;
		if (pos == cnt) {
			host->bounce_buf_data[0] = (val >> 8) & 0xff;
			host->cmd_flags |= DATA_CARRY;
			break;
		}
		buf[pos++] = (val >> 8) & 0xff;
	}
	kunmap_atomic(buf - off, KM_BIO_DST_IRQ);
}

static void tifm_sd_write_fifo(struct tifm_sd *host, struct page *pg,
			       unsigned int off, unsigned int cnt)
{
	struct tifm_dev *sock = host->dev;
	unsigned char *buf;
	unsigned int pos = 0, val;

	buf = kmap_atomic(pg, KM_BIO_SRC_IRQ) + off;
	if (host->cmd_flags & DATA_CARRY) {
		val = host->bounce_buf_data[0] | ((buf[pos++] << 8) & 0xff00);
		writel(val, sock->addr + SOCK_MMCSD_DATA);
		host->cmd_flags &= ~DATA_CARRY;
	}

	while (pos < cnt) {
		val = buf[pos++];
		if (pos == cnt) {
			host->bounce_buf_data[0] = val & 0xff;
			host->cmd_flags |= DATA_CARRY;
			break;
		}
		val |= (buf[pos++] << 8) & 0xff00;
		writel(val, sock->addr + SOCK_MMCSD_DATA);
	}
	kunmap_atomic(buf - off, KM_BIO_SRC_IRQ);
}

static void tifm_sd_transfer_data(struct tifm_sd *host)
{
	struct mmc_data *r_data = host->req->cmd->data;
	struct scatterlist *sg = r_data->sg;
	unsigned int off, cnt, t_size = TIFM_MMCSD_FIFO_SIZE * 2;
	unsigned int p_off, p_cnt;
	struct page *pg;

	if (host->sg_pos == host->sg_len)
		return;
	while (t_size) {
		cnt = sg[host->sg_pos].length - host->block_pos;
		if (!cnt) {
			host->block_pos = 0;
			host->sg_pos++;
			if (host->sg_pos == host->sg_len) {
				if ((r_data->flags & MMC_DATA_WRITE)
				    && DATA_CARRY)
					writel(host->bounce_buf_data[0],
					       host->dev->addr
					       + SOCK_MMCSD_DATA);

				return;
			}
			cnt = sg[host->sg_pos].length;
		}
		off = sg[host->sg_pos].offset + host->block_pos;

		pg = nth_page(sg_page(&sg[host->sg_pos]), off >> PAGE_SHIFT);
		p_off = offset_in_page(off);
		p_cnt = PAGE_SIZE - p_off;
		p_cnt = min(p_cnt, cnt);
		p_cnt = min(p_cnt, t_size);

		if (r_data->flags & MMC_DATA_READ)
			tifm_sd_read_fifo(host, pg, p_off, p_cnt);
		else if (r_data->flags & MMC_DATA_WRITE)
			tifm_sd_write_fifo(host, pg, p_off, p_cnt);

		t_size -= p_cnt;
		host->block_pos += p_cnt;
	}
}

static void tifm_sd_copy_page(struct page *dst, unsigned int dst_off,
			      struct page *src, unsigned int src_off,
			      unsigned int count)
{
	unsigned char *src_buf = kmap_atomic(src, KM_BIO_SRC_IRQ) + src_off;
	unsigned char *dst_buf = kmap_atomic(dst, KM_BIO_DST_IRQ) + dst_off;

	memcpy(dst_buf, src_buf, count);

	kunmap_atomic(dst_buf - dst_off, KM_BIO_DST_IRQ);
	kunmap_atomic(src_buf - src_off, KM_BIO_SRC_IRQ);
}

static void tifm_sd_bounce_block(struct tifm_sd *host, struct mmc_data *r_data)
{
	struct scatterlist *sg = r_data->sg;
	unsigned int t_size = r_data->blksz;
	unsigned int off, cnt;
	unsigned int p_off, p_cnt;
	struct page *pg;

	dev_dbg(&host->dev->dev, "bouncing block\n");
	while (t_size) {
		cnt = sg[host->sg_pos].length - host->block_pos;
		if (!cnt) {
			host->block_pos = 0;
			host->sg_pos++;
			if (host->sg_pos == host->sg_len)
				return;
			cnt = sg[host->sg_pos].length;
		}
		off = sg[host->sg_pos].offset + host->block_pos;

		pg = nth_page(sg_page(&sg[host->sg_pos]), off >> PAGE_SHIFT);
		p_off = offset_in_page(off);
		p_cnt = PAGE_SIZE - p_off;
		p_cnt = min(p_cnt, cnt);
		p_cnt = min(p_cnt, t_size);

		if (r_data->flags & MMC_DATA_WRITE)
			tifm_sd_copy_page(sg_page(&host->bounce_buf),
					  r_data->blksz - t_size,
					  pg, p_off, p_cnt);
		else if (r_data->flags & MMC_DATA_READ)
			tifm_sd_copy_page(pg, p_off, sg_page(&host->bounce_buf),
					  r_data->blksz - t_size, p_cnt);

		t_size -= p_cnt;
		host->block_pos += p_cnt;
	}
}

static int tifm_sd_set_dma_data(struct tifm_sd *host, struct mmc_data *r_data)
{
	struct tifm_dev *sock = host->dev;
	unsigned int t_size = TIFM_DMA_TSIZE * r_data->blksz;
	unsigned int dma_len, dma_blk_cnt, dma_off;
	struct scatterlist *sg = NULL;
	unsigned long flags;

	if (host->sg_pos == host->sg_len)
		return 1;

	if (host->cmd_flags & DATA_CARRY) {
		host->cmd_flags &= ~DATA_CARRY;
		local_irq_save(flags);
		tifm_sd_bounce_block(host, r_data);
		local_irq_restore(flags);
		if (host->sg_pos == host->sg_len)
			return 1;
	}

	dma_len = sg_dma_len(&r_data->sg[host->sg_pos]) - host->block_pos;
	if (!dma_len) {
		host->block_pos = 0;
		host->sg_pos++;
		if (host->sg_pos == host->sg_len)
			return 1;
		dma_len = sg_dma_len(&r_data->sg[host->sg_pos]);
	}

	if (dma_len < t_size) {
		dma_blk_cnt = dma_len / r_data->blksz;
		dma_off = host->block_pos;
		host->block_pos += dma_blk_cnt * r_data->blksz;
	} else {
		dma_blk_cnt = TIFM_DMA_TSIZE;
		dma_off = host->block_pos;
		host->block_pos += t_size;
	}

	if (dma_blk_cnt)
		sg = &r_data->sg[host->sg_pos];
	else if (dma_len) {
		if (r_data->flags & MMC_DATA_WRITE) {
			local_irq_save(flags);
			tifm_sd_bounce_block(host, r_data);
			local_irq_restore(flags);
		} else
			host->cmd_flags |= DATA_CARRY;

		sg = &host->bounce_buf;
		dma_off = 0;
		dma_blk_cnt = 1;
	} else
		return 1;

	dev_dbg(&sock->dev, "setting dma for %d blocks\n", dma_blk_cnt);
	writel(sg_dma_address(sg) + dma_off, sock->addr + SOCK_DMA_ADDRESS);
	if (r_data->flags & MMC_DATA_WRITE)
		writel((dma_blk_cnt << 8) | TIFM_DMA_TX | TIFM_DMA_EN,
		       sock->addr + SOCK_DMA_CONTROL);
	else
		writel((dma_blk_cnt << 8) | TIFM_DMA_EN,
		       sock->addr + SOCK_DMA_CONTROL);

	return 0;
}

static unsigned int tifm_sd_op_flags(struct mmc_command *cmd)
{
	unsigned int rc = 0;

	switch (mmc_resp_type(cmd)) {
	case MMC_RSP_NONE:
		rc |= TIFM_MMCSD_RSP_R0;
		break;
	case MMC_RSP_R1B:
		rc |= TIFM_MMCSD_RSP_BUSY; // deliberate fall-through
	case MMC_RSP_R1:
		rc |= TIFM_MMCSD_RSP_R1;
		break;
	case MMC_RSP_R2:
		rc |= TIFM_MMCSD_RSP_R2;
		break;
	case MMC_RSP_R3:
		rc |= TIFM_MMCSD_RSP_R3;
		break;
	default:
		BUG();
	}

	switch (mmc_cmd_type(cmd)) {
	case MMC_CMD_BC:
		rc |= TIFM_MMCSD_CMD_BC;
		break;
	case MMC_CMD_BCR:
		rc |= TIFM_MMCSD_CMD_BCR;
		break;
	case MMC_CMD_AC:
		rc |= TIFM_MMCSD_CMD_AC;
		break;
	case MMC_CMD_ADTC:
		rc |= TIFM_MMCSD_CMD_ADTC;
		break;
	default:
		BUG();
	}
	return rc;
}

static void tifm_sd_exec(struct tifm_sd *host, struct mmc_command *cmd)
{
	struct tifm_dev *sock = host->dev;
	unsigned int cmd_mask = tifm_sd_op_flags(cmd);

	if (host->open_drain)
		cmd_mask |= TIFM_MMCSD_ODTO;

	if (cmd->data && (cmd->data->flags & MMC_DATA_READ))
		cmd_mask |= TIFM_MMCSD_READ;

	dev_dbg(&sock->dev, "executing opcode 0x%x, arg: 0x%x, mask: 0x%x\n",
		cmd->opcode, cmd->arg, cmd_mask);

	writel((cmd->arg >> 16) & 0xffff, sock->addr + SOCK_MMCSD_ARG_HIGH);
	writel(cmd->arg & 0xffff, sock->addr + SOCK_MMCSD_ARG_LOW);
	writel(cmd->opcode | cmd_mask, sock->addr + SOCK_MMCSD_COMMAND);
}

static void tifm_sd_fetch_resp(struct mmc_command *cmd, struct tifm_dev *sock)
{
	cmd->resp[0] = (readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x1c) << 16)
		       | readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x18);
	cmd->resp[1] = (readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x14) << 16)
		       | readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x10);
	cmd->resp[2] = (readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x0c) << 16)
		       | readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x08);
	cmd->resp[3] = (readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x04) << 16)
		       | readl(sock->addr + SOCK_MMCSD_RESPONSE + 0x00);
}

static void tifm_sd_check_status(struct tifm_sd *host)
{
	struct tifm_dev *sock = host->dev;
	struct mmc_command *cmd = host->req->cmd;

	if (cmd->error)
		goto finish_request;

	if (!(host->cmd_flags & CMD_READY))
		return;

	if (cmd->data) {
		if (cmd->data->error) {
			if ((host->cmd_flags & SCMD_ACTIVE)
			    && !(host->cmd_flags & SCMD_READY))
				return;

			goto finish_request;
		}

		if (!(host->cmd_flags & BRS_READY))
			return;

		if (!(host->no_dma || (host->cmd_flags & FIFO_READY)))
			return;

		if (cmd->data->flags & MMC_DATA_WRITE) {
			if (host->req->stop) {
				if (!(host->cmd_flags & SCMD_ACTIVE)) {
					host->cmd_flags |= SCMD_ACTIVE;
					writel(TIFM_MMCSD_EOFB
					       | readl(sock->addr
						       + SOCK_MMCSD_INT_ENABLE),
					       sock->addr
					       + SOCK_MMCSD_INT_ENABLE);
					tifm_sd_exec(host, host->req->stop);
					return;
				} else {
					if (!(host->cmd_flags & SCMD_READY)
					    || (host->cmd_flags & CARD_BUSY))
						return;
					writel((~TIFM_MMCSD_EOFB)
					       & readl(sock->addr
						       + SOCK_MMCSD_INT_ENABLE),
					       sock->addr
					       + SOCK_MMCSD_INT_ENABLE);
				}
			} else {
				if (host->cmd_flags & CARD_BUSY)
					return;
				writel((~TIFM_MMCSD_EOFB)
				       & readl(sock->addr
					       + SOCK_MMCSD_INT_ENABLE),
				       sock->addr + SOCK_MMCSD_INT_ENABLE);
			}
		} else {
			if (host->req->stop) {
				if (!(host->cmd_flags & SCMD_ACTIVE)) {
					host->cmd_flags |= SCMD_ACTIVE;
					tifm_sd_exec(host, host->req->stop);
					return;
				} else {
					if (!(host->cmd_flags & SCMD_READY))
						return;
				}
			}
		}
	}
finish_request:
	tasklet_schedule(&host->finish_tasklet);
}

/* Called from interrupt handler */
static void tifm_sd_data_event(struct tifm_dev *sock)
{
	struct tifm_sd *host;
	unsigned int fifo_status = 0;
	struct mmc_data *r_data = NULL;

	spin_lock(&sock->lock);
	host = mmc_priv((struct mmc_host*)tifm_get_drvdata(sock));
	fifo_status = readl(sock->addr + SOCK_DMA_FIFO_STATUS);
	dev_dbg(&sock->dev, "data event: fifo_status %x, flags %x\n",
		fifo_status, host->cmd_flags);

	if (host->req) {
		r_data = host->req->cmd->data;

		if (r_data && (fifo_status & TIFM_FIFO_READY)) {
			if (tifm_sd_set_dma_data(host, r_data)) {
				host->cmd_flags |= FIFO_READY;
				tifm_sd_check_status(host);
			}
		}
	}

	writel(fifo_status, sock->addr + SOCK_DMA_FIFO_STATUS);
	spin_unlock(&sock->lock);
}

/* Called from interrupt handler */
static void tifm_sd_card_event(struct tifm_dev *sock)
{
	struct tifm_sd *host;
	unsigned int host_status = 0;
	int cmd_error = 0;
	struct mmc_command *cmd = NULL;
	unsigned long flags;

	spin_lock(&sock->lock);
	host = mmc_priv((struct mmc_host*)tifm_get_drvdata(sock));
	host_status = readl(sock->addr + SOCK_MMCSD_STATUS);
	dev_dbg(&sock->dev, "host event: host_status %x, flags %x\n",
		host_status, host->cmd_flags);

	if (host->req) {
		cmd = host->req->cmd;

		if (host_status & TIFM_MMCSD_ERRMASK) {
			writel(host_status & TIFM_MMCSD_ERRMASK,
			       sock->addr + SOCK_MMCSD_STATUS);
			if (host_status & TIFM_MMCSD_CTO)
				cmd_error = -ETIMEDOUT;
			else if (host_status & TIFM_MMCSD_CCRC)
				cmd_error = -EILSEQ;

			if (cmd->data) {
				if (host_status & TIFM_MMCSD_DTO)
					cmd->data->error = -ETIMEDOUT;
				else if (host_status & TIFM_MMCSD_DCRC)
					cmd->data->error = -EILSEQ;
			}

			writel(TIFM_FIFO_INT_SETALL,
			       sock->addr + SOCK_DMA_FIFO_INT_ENABLE_CLEAR);
			writel(TIFM_DMA_RESET, sock->addr + SOCK_DMA_CONTROL);

			if (host->req->stop) {
				if (host->cmd_flags & SCMD_ACTIVE) {
					host->req->stop->error = cmd_error;
					host->cmd_flags |= SCMD_READY;
				} else {
					cmd->error = cmd_error;
					host->cmd_flags |= SCMD_ACTIVE;
					tifm_sd_exec(host, host->req->stop);
					goto done;
				}