mmc: Driver for CB710/720 memory card reader (MMC part)

The code is divided in two parts. There is a virtual 'bus' driver
that handles PCI device and registers three new devices one per card
reader type. The other driver handles SD/MMC part of the reader.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>

4 files changed, 922 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index b4cf691..75337e4 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -241,3 +241,16 @@ config MMC_TMIO
 	help
 	  This provides support for the SD/MMC cell found in TC6393XB,
 	  T7L66XB and also ipaq ASIC3
+
+config MMC_CB710
+	tristate "ENE CB710 MMC/SD Interface support"
+	depends on PCI
+	select CB710_CORE
+	help
+	  This option enables support for MMC/SD part of ENE CB710/720 Flash
+	  memory card reader found in some laptops (ie. some versions of
+	  HP Compaq nx9500).
+
+	  This driver can also be built as a module. If so, the module
+	  will be called cb710-mmc.
+
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 970a997..ce9c8b6 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -29,4 +29,5 @@ endif
 obj-$(CONFIG_MMC_S3C)   	+= s3cmci.o
 obj-$(CONFIG_MMC_SDRICOH_CS)	+= sdricoh_cs.o
 obj-$(CONFIG_MMC_TMIO)		+= tmio_mmc.o
+obj-$(CONFIG_MMC_CB710)	+= cb710-mmc.o
 
diff --git a/drivers/mmc/host/cb710-mmc.c b/drivers/mmc/host/cb710-mmc.c
new file mode 100644
index 0000000..bc048aa
--- /dev/null
+++ b/drivers/mmc/host/cb710-mmc.c
@@ -0,0 +1,804 @@
+/*
+ *  cb710/mmc.c
+ *
+ *  Copyright by Michał Mirosław, 2008-2009
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include "cb710-mmc.h"
+
+static const u8 cb710_clock_divider_log2[8] = {
+/*	1, 2, 4, 8, 16, 32, 128, 512 */
+	0, 1, 2, 3,  4,  5,   7,   9
+};
+#define CB710_MAX_DIVIDER_IDX	\
+	(ARRAY_SIZE(cb710_clock_divider_log2) - 1)
+
+static const u8 cb710_src_freq_mhz[16] = {
+	33, 10, 20, 25, 30, 35, 40, 45,
+	50, 55, 60, 65, 70, 75, 80, 85
+};
+
+static void cb710_mmc_set_clock(struct mmc_host *mmc, int hz)
+{
+	struct cb710_slot *slot = cb710_mmc_to_slot(mmc);
+	struct pci_dev *pdev = cb710_slot_to_chip(slot)->pdev;
+	u32 src_freq_idx;
+	u32 divider_idx;
+	int src_hz;
+
+	/* this is magic, unverifiable for me, unless I get
+	 * MMC card with cables connected to bus signals */
+	pci_read_config_dword(pdev, 0x48, &src_freq_idx);
+	src_freq_idx = (src_freq_idx >> 16) & 0xF;
+	src_hz = cb710_src_freq_mhz[src_freq_idx] * 1000000;
+
+	for (divider_idx = 0; divider_idx < CB710_MAX_DIVIDER_IDX; ++divider_idx) {
+		if (hz >= src_hz >> cb710_clock_divider_log2[divider_idx])
+			break;
+	}
+
+	if (src_freq_idx)
+		divider_idx |= 0x8;
+
+	cb710_pci_update_config_reg(pdev, 0x40, ~0xF0000000, divider_idx << 28);
+
+	dev_dbg(cb710_slot_dev(slot),
+		"clock set to %d Hz, wanted %d Hz; flag = %d\n",
+		src_hz >> cb710_clock_divider_log2[divider_idx & 7],
+		hz, (divider_idx & 8) != 0);
+}
+
+static void __cb710_mmc_enable_irq(struct cb710_slot *slot,
+	unsigned short enable, unsigned short mask)
+{
+	/* clear global IE
+	 * - it gets set later if any interrupt sources are enabled */
+	mask |= CB710_MMC_IE_IRQ_ENABLE;
+
+	/* look like interrupt is fired whenever
+	 * WORD[0x0C] & WORD[0x10] != 0;
+	 * -> bit 15 port 0x0C seems to be global interrupt enable
+	 */
+
+	enable = (cb710_read_port_16(slot, CB710_MMC_IRQ_ENABLE_PORT)
+		& ~mask) | enable;
+
+	if (enable)
+		enable |= CB710_MMC_IE_IRQ_ENABLE;
+
+	cb710_write_port_16(slot, CB710_MMC_IRQ_ENABLE_PORT, enable);
+}
+
+static void cb710_mmc_enable_irq(struct cb710_slot *slot,
+	unsigned short enable, unsigned short mask)
+{
+	struct cb710_mmc_reader *reader = mmc_priv(cb710_slot_to_mmc(slot));
+	unsigned long flags;
+
+	spin_lock_irqsave(&reader->irq_lock, flags);
+	/* this is the only thing irq_lock protects */
+	__cb710_mmc_enable_irq(slot, enable, mask);
+	spin_unlock_irqrestore(&reader->irq_lock, flags);
+}
+
+static void cb710_mmc_reset_events(struct cb710_slot *slot)
+{
+	cb710_write_port_8(slot, CB710_MMC_STATUS0_PORT, 0xFF);
+	cb710_write_port_8(slot, CB710_MMC_STATUS1_PORT, 0xFF);
+	cb710_write_port_8(slot, CB710_MMC_STATUS2_PORT, 0xFF);
+}
+
+static int cb710_mmc_is_card_inserted(struct cb710_slot *slot)
+{
+	return cb710_read_port_8(slot, CB710_MMC_STATUS3_PORT)
+		& CB710_MMC_S3_CARD_DETECTED;
+}
+
+static void cb710_mmc_enable_4bit_data(struct cb710_slot *slot, int enable)
+{
+	dev_dbg(cb710_slot_dev(slot), "configuring %d-data-line%s mode\n",
+		enable ? 4 : 1, enable ? "s" : "");
+	if (enable)
+		cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT,
+			CB710_MMC_C1_4BIT_DATA_BUS, 0);
+	else
+		cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT,
+			0, CB710_MMC_C1_4BIT_DATA_BUS);
+}
+
+static int cb710_check_event(struct cb710_slot *slot, u8 what)
+{
+	u16 status;
+
+	status = cb710_read_port_16(slot, CB710_MMC_STATUS_PORT);
+
+	if (status & CB710_MMC_S0_FIFO_UNDERFLOW) {
+		/* it is just a guess, so log it */
+		dev_dbg(cb710_slot_dev(slot),
+			"CHECK : ignoring bit 6 in status %04X\n", status);
+		cb710_write_port_8(slot, CB710_MMC_STATUS0_PORT,
+			CB710_MMC_S0_FIFO_UNDERFLOW);
+		status &= ~CB710_MMC_S0_FIFO_UNDERFLOW;
+	}
+
+	if (status & CB710_MMC_STATUS_ERROR_EVENTS) {
+		dev_dbg(cb710_slot_dev(slot),
+			"CHECK : returning EIO on status %04X\n", status);
+		cb710_write_port_8(slot, CB710_MMC_STATUS0_PORT, status & 0xFF);
+		cb710_write_port_8(slot, CB710_MMC_STATUS1_PORT,
+			CB710_MMC_S1_RESET);
+		return -EIO;
+	}
+
+	/* 'what' is a bit in MMC_STATUS1 */
+	if ((status >> 8) & what) {
+		cb710_write_port_8(slot, CB710_MMC_STATUS1_PORT, what);
+		return 1;
+	}
+
+	return 0;
+}
+
+static int cb710_wait_for_event(struct cb710_slot *slot, u8 what)
+{
+	int err = 0;
+	unsigned limit = 2000000;	/* FIXME: real timeout */
+
+#ifdef CONFIG_CB710_DEBUG
+	u32 e, x;
+	e = cb710_read_port_32(slot, CB710_MMC_STATUS_PORT);
+#endif
+
+	while (!(err = cb710_check_event(slot, what))) {
+		if (!--limit) {
+			cb710_dump_regs(cb710_slot_to_chip(slot),
+				CB710_DUMP_REGS_MMC);
+			err = -ETIMEDOUT;
+			break;
+		}
+		udelay(1);
+	}
+
+#ifdef CONFIG_CB710_DEBUG
+	x = cb710_read_port_32(slot, CB710_MMC_STATUS_PORT);
+
+	limit = 2000000 - limit;
+	if (limit > 100)
+		dev_dbg(cb710_slot_dev(slot),
+			"WAIT10: waited %d loops, what %d, entry val %08X, exit val %08X\n",
+			limit, what, e, x);
+#endif
+	return err < 0 ? err : 0;
+}
+
+
+static int cb710_wait_while_busy(struct cb710_slot *slot, uint8_t mask)
+{
+	unsigned limit = 500000;	/* FIXME: real timeout */
+	int err = 0;
+
+#ifdef CONFIG_CB710_DEBUG
+	u32 e, x;
+	e = cb710_read_port_32(slot, CB710_MMC_STATUS_PORT);
+#endif
+
+	while (cb710_read_port_8(slot, CB710_MMC_STATUS2_PORT) & mask) {
+		if (!--limit) {
+			cb710_dump_regs(cb710_slot_to_chip(slot),
+				CB710_DUMP_REGS_MMC);
+			err = -ETIMEDOUT;
+			break;
+		}
+		udelay(1);
+	}
+
+#ifdef CONFIG_CB710_DEBUG
+	x = cb710_read_port_32(slot, CB710_MMC_STATUS_PORT);
+
+	limit = 500000 - limit;
+	if (limit > 100)
+		dev_dbg(cb710_slot_dev(slot),
+			"WAIT12: waited %d loops, mask %02X, entry val %08X, exit val %08X\n",
+			limit, mask, e, x);
+#endif
+	return 0;
+}
+
+static void cb710_mmc_set_transfer_size(struct cb710_slot *slot,
+	size_t count, size_t blocksize)
+{
+	cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	cb710_write_port_32(slot, CB710_MMC_TRANSFER_SIZE_PORT,
+		((count - 1) << 16)|(blocksize - 1));
+
+	dev_vdbg(cb710_slot_dev(slot), "set up for %d block%s of %d bytes\n",
+		count, count == 1 ? "" : "s", blocksize);
+}
+
+static void cb710_mmc_fifo_hack(struct cb710_slot *slot)
+{
+	/* without this, received data is prepended with 8-bytes of zeroes */
+	u32 r1, r2;
+	int ok = 0;
+
+	r1 = cb710_read_port_32(slot, CB710_MMC_DATA_PORT);
+	r2 = cb710_read_port_32(slot, CB710_MMC_DATA_PORT);
+	if (cb710_read_port_8(slot, CB710_MMC_STATUS0_PORT)
+	    & CB710_MMC_S0_FIFO_UNDERFLOW) {
+		cb710_write_port_8(slot, CB710_MMC_STATUS0_PORT,
+			CB710_MMC_S0_FIFO_UNDERFLOW);
+		ok = 1;
+	}
+
+	dev_dbg(cb710_slot_dev(slot),
+		"FIFO-read-hack: expected STATUS0 bit was %s\n",
+		ok ? "set." : "NOT SET!");
+	dev_dbg(cb710_slot_dev(slot),
+		"FIFO-read-hack: dwords ignored: %08X %08X - %s\n",
+		r1, r2, (r1|r2) ? "BAD (NOT ZERO)!" : "ok");
+}
+
+static int cb710_mmc_receive_pio(struct cb710_slot *slot,
+	struct sg_mapping_iter *miter, size_t dw_count)
+{
+	if (!(cb710_read_port_8(slot, CB710_MMC_STATUS2_PORT) & CB710_MMC_S2_FIFO_READY)) {
+		int err = cb710_wait_for_event(slot,
+			CB710_MMC_S1_PIO_TRANSFER_DONE);
+		if (err)
+			return err;
+	}
+
+	cb710_sg_dwiter_write_from_io(miter,
+		slot->iobase + CB710_MMC_DATA_PORT, dw_count);
+
+	return 0;
+}
+
+static bool cb710_is_transfer_size_supported(struct mmc_data *data)
+{
+	return !(data->blksz & 15 && (data->blocks != 1 || data->blksz != 8));
+}
+
+static int cb710_mmc_receive(struct cb710_slot *slot, struct mmc_data *data)
+{
+	struct sg_mapping_iter miter;
+	size_t len, blocks = data->blocks;
+	int err = 0;
+
+	/* TODO: I don't know how/if the hardware handles non-16B-boundary blocks
+	 * except single 8B block */
+	if (unlikely(data->blksz & 15 && (data->blocks != 1 || data->blksz != 8)))
+		return -EINVAL;
+
+	sg_miter_start(&miter, data->sg, data->sg_len, 0);
+
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG2_PORT,
+		15, CB710_MMC_C2_READ_PIO_SIZE_MASK);
+
+	cb710_mmc_fifo_hack(slot);
+
+	while (blocks-- > 0) {
+		len = data->blksz;
+
+		while (len >= 16) {
+			err = cb710_mmc_receive_pio(slot, &miter, 4);
+			if (err)
+				goto out;
+			len -= 16;
+		}
+
+		if (!len)
+			continue;
+
+		cb710_modify_port_8(slot, CB710_MMC_CONFIG2_PORT,
+			len - 1, CB710_MMC_C2_READ_PIO_SIZE_MASK);
+
+		len = (len >= 8) ? 4 : 2;
+		err = cb710_mmc_receive_pio(slot, &miter, len);
+		if (err)
+			goto out;
+	}
+out:
+	cb710_sg_miter_stop_writing(&miter);
+	return err;
+}
+
+static int cb710_mmc_send(struct cb710_slot *slot, struct mmc_data *data)
+{
+	struct sg_mapping_iter miter;
+	size_t len, blocks = data->blocks;
+	int err = 0;
+
+	/* TODO: I don't know how/if the hardware handles multiple
+	 * non-16B-boundary blocks */
+	if (unlikely(data->blocks > 1 && data->blksz & 15))
+		return -EINVAL;
+
+	sg_miter_start(&miter, data->sg, data->sg_len, 0);
+
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG2_PORT,
+		0, CB710_MMC_C2_READ_PIO_SIZE_MASK);
+
+	while (blocks-- > 0) {
+		len = (data->blksz + 15) >> 4;
+		do {
+			if (!(cb710_read_port_8(slot, CB710_MMC_STATUS2_PORT)
+			    & CB710_MMC_S2_FIFO_EMPTY)) {
+				err = cb710_wait_for_event(slot,
+					CB710_MMC_S1_PIO_TRANSFER_DONE);
+				if (err)
+					goto out;
+			}
+			cb710_sg_dwiter_read_to_io(&miter,
+				slot->iobase + CB710_MMC_DATA_PORT, 4);
+		} while (--len);
+	}
+out:
+	sg_miter_stop(&miter);
+	return err;
+}
+
+static u16 cb710_encode_cmd_flags(struct cb710_mmc_reader *reader,
+	struct mmc_command *cmd)
+{
+	unsigned int flags = cmd->flags;
+	u16 cb_flags = 0;
+
+	/* Windows driver returned 0 for commands for which no response
+	 * is expected. It happened that there were only two such commands
+	 * used: MMC_GO_IDLE_STATE and MMC_GO_INACTIVE_STATE so it might
+	 * as well be a bug in that driver.
+	 *
+	 * Original driver set bit 14 for MMC/SD application
+	 * commands. There's no difference 'on the wire' and
+	 * it apparently works without it anyway.
+	 */
+
+	switch (flags & MMC_CMD_MASK) {
+	case MMC_CMD_AC:	cb_flags = CB710_MMC_CMD_AC;	break;
+	case MMC_CMD_ADTC:	cb_flags = CB710_MMC_CMD_ADTC;	break;
+	case MMC_CMD_BC:	cb_flags = CB710_MMC_CMD_BC;	break;
+	case MMC_CMD_BCR:	cb_flags = CB710_MMC_CMD_BCR;	break;
+	}
+
+	if (flags & MMC_RSP_BUSY)
+		cb_flags |= CB710_MMC_RSP_BUSY;
+
+	cb_flags |= cmd->opcode << CB710_MMC_CMD_CODE_SHIFT;
+
+	if (cmd->data && (cmd->data->flags & MMC_DATA_READ))
+		cb_flags |= CB710_MMC_DATA_READ;
+
+	if (flags & MMC_RSP_PRESENT) {
+		/* Windows driver set 01 at bits 4,3 except for
+		 * MMC_SET_BLOCKLEN where it set 10. Maybe the
+		 * hardware can do something special about this
+		 * command? The original driver looks buggy/incomplete
+		 * anyway so we ignore this for now.
+		 *
+		 * I assume that 00 here means no response is expected.
+		 */
+		cb_flags |= CB710_MMC_RSP_PRESENT;
+
+		if (flags & MMC_RSP_136)
+			cb_flags |= CB710_MMC_RSP_136;
+		if (!(flags & MMC_RSP_CRC))
+			cb_flags |= CB710_MMC_RSP_NO_CRC;
+	}
+
+	return cb_flags;
+}
+
+static void cb710_receive_response(struct cb710_slot *slot,
+	struct mmc_command *cmd)
+{
+	unsigned rsp_opcode, wanted_opcode;
+
+	/* Looks like final byte with CRC is always stripped (same as SDHCI) */
+	if (cmd->flags & MMC_RSP_136) {
+		u32 resp[4];
+
+		resp[0] = cb710_read_port_32(slot, CB710_MMC_RESPONSE3_PORT);
+		resp[1] = cb710_read_port_32(slot, CB710_MMC_RESPONSE2_PORT);
+		resp[2] = cb710_read_port_32(slot, CB710_MMC_RESPONSE1_PORT);
+		resp[3] = cb710_read_port_32(slot, CB710_MMC_RESPONSE0_PORT);
+		rsp_opcode = resp[0] >> 24;
+
+		cmd->resp[0] = (resp[0] << 8)|(resp[1] >> 24);
+		cmd->resp[1] = (resp[1] << 8)|(resp[2] >> 24);
+		cmd->resp[2] = (resp[2] << 8)|(resp[3] >> 24);
+		cmd->resp[3] = (resp[3] << 8);
+	} else {
+		rsp_opcode = cb710_read_port_32(slot, CB710_MMC_RESPONSE1_PORT) & 0x3F;
+		cmd->resp[0] = cb710_read_port_32(slot, CB710_MMC_RESPONSE0_PORT);
+	}
+
+	wanted_opcode = (cmd->flags & MMC_RSP_OPCODE) ? cmd->opcode : 0x3F;
+	if (rsp_opcode != wanted_opcode)
+		cmd->error = -EILSEQ;
+}
+
+static int cb710_mmc_transfer_data(struct cb710_slot *slot,
+	struct mmc_data *data)
+{
+	int error, to;
+
+	if (data->flags & MMC_DATA_READ)
+		error = cb710_mmc_receive(slot, data);
+	else
+		error = cb710_mmc_send(slot, data);
+
+	to = cb710_wait_for_event(slot, CB710_MMC_S1_DATA_TRANSFER_DONE);
+	if (!error)
+		error = to;
+
+	if (!error)
+		data->bytes_xfered = data->blksz * data->blocks;
+	return error;
+}
+
+static int cb710_mmc_command(struct mmc_host *mmc, struct mmc_command *cmd)
+{
+	struct cb710_slot *slot = cb710_mmc_to_slot(mmc);
+	struct cb710_mmc_reader *reader = mmc_priv(mmc);
+	struct mmc_data *data = cmd->data;
+
+	u16 cb_cmd = cb710_encode_cmd_flags(reader, cmd);
+	dev_dbg(cb710_slot_dev(slot), "cmd request: 0x%04X\n", cb_cmd);
+
+	if (data) {
+		if (!cb710_is_transfer_size_supported(data)) {
+			data->error = -EINVAL;
+			return -1;
+		}
+		cb710_mmc_set_transfer_size(slot, data->blocks, data->blksz);
+	}
+
+	cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20|CB710_MMC_S2_BUSY_10);
+	cb710_write_port_16(slot, CB710_MMC_CMD_TYPE_PORT, cb_cmd);
+	cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	cb710_write_port_32(slot, CB710_MMC_CMD_PARAM_PORT, cmd->arg);
+	cb710_mmc_reset_events(slot);
+	cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG0_PORT, 0x01, 0);
+
+	cmd->error = cb710_wait_for_event(slot, CB710_MMC_S1_COMMAND_SENT);
+	if (cmd->error)
+		return -1;
+
+	if (cmd->flags & MMC_RSP_PRESENT) {
+		cb710_receive_response(slot, cmd);
+		if (cmd->error)
+			return -1;
+	}
+
+	if (data)
+		data->error = cb710_mmc_transfer_data(slot, data);
+	return 0;
+}
+
+static void cb710_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+	struct cb710_slot *slot = cb710_mmc_to_slot(mmc);
+	struct cb710_mmc_reader *reader = mmc_priv(mmc);
+
+	WARN_ON(reader->mrq != NULL);
+
+	reader->mrq = mrq;
+	cb710_mmc_enable_irq(slot, CB710_MMC_IE_TEST_MASK, 0);
+
+	if (cb710_mmc_is_card_inserted(slot)) {
+		if (!cb710_mmc_command(mmc, mrq->cmd) && mrq->stop)
+			cb710_mmc_command(mmc, mrq->stop);
+		mdelay(1);
+	} else {
+		mrq->cmd->error = -ENOMEDIUM;
+	}
+
+	tasklet_schedule(&reader->finish_req_tasklet);
+}
+
+static int cb710_mmc_powerup(struct cb710_slot *slot)
+{
+#ifdef CONFIG_CB710_DEBUG
+	struct cb710_chip *chip = cb710_slot_to_chip(slot);
+#endif
+	int err;
+
+	/* a lot of magic; see comment in cb710_mmc_set_clock() */
+	dev_dbg(cb710_slot_dev(slot), "bus powerup\n");
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	err = cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	if (unlikely(err))
+		return err;
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT, 0x80, 0);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG3_PORT, 0x80, 0);
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	mdelay(1);
+	dev_dbg(cb710_slot_dev(slot), "after delay 1\n");
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	err = cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	if (unlikely(err))
+		return err;
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT, 0x09, 0);
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	mdelay(1);
+	dev_dbg(cb710_slot_dev(slot), "after delay 2\n");
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	err = cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	if (unlikely(err))
+		return err;
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT, 0, 0x08);
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	mdelay(2);
+	dev_dbg(cb710_slot_dev(slot), "after delay 3\n");
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG0_PORT, 0x06, 0);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT, 0x70, 0);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG2_PORT, 0x80, 0);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG3_PORT, 0x03, 0);
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	err = cb710_wait_while_busy(slot, CB710_MMC_S2_BUSY_20);
+	if (unlikely(err))
+		return err;
+	/* This port behaves weird: quick byte reads of 0x08,0x09 return
+	 * 0xFF,0x00 after writing 0xFFFF to 0x08; it works correctly when
+	 * read/written from userspace...  What am I missing here?
+	 * (it doesn't depend on write-to-read delay) */
+	cb710_write_port_16(slot, CB710_MMC_CONFIGB_PORT, 0xFFFF);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG0_PORT, 0x06, 0);
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+	dev_dbg(cb710_slot_dev(slot), "bus powerup finished\n");
+
+	return cb710_check_event(slot, 0);
+}
+
+static void cb710_mmc_powerdown(struct cb710_slot *slot)
+{
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG1_PORT, 0, 0x81);
+	cb710_modify_port_8(slot, CB710_MMC_CONFIG3_PORT, 0, 0x80);
+}
+
+static void cb710_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+	struct cb710_slot *slot = cb710_mmc_to_slot(mmc);
+	struct cb710_mmc_reader *reader = mmc_priv(mmc);
+	int err;
+
+	cb710_mmc_set_clock(mmc, ios->clock);
+
+	if (!cb710_mmc_is_card_inserted(slot)) {
+		dev_dbg(cb710_slot_dev(slot),
+			"no card inserted - ignoring bus powerup request\n");
+		ios->power_mode = MMC_POWER_OFF;
+	}
+
+	if (ios->power_mode != reader->last_power_mode)
+	switch (ios->power_mode) {
+	case MMC_POWER_ON:
+		err = cb710_mmc_powerup(slot);
+		if (err) {
+			dev_warn(cb710_slot_dev(slot),
+				"powerup failed (%d)- retrying\n", err);
+			cb710_mmc_powerdown(slot);
+			udelay(1);
+			err = cb710_mmc_powerup(slot);
+			if (err)
+				dev_warn(cb710_slot_dev(slot),
+					"powerup retry failed (%d) - expect errors\n",
+					err);
+		}
+		reader->last_power_mode = MMC_POWER_ON;
+		break;
+	case MMC_POWER_OFF:
+		cb710_mmc_powerdown(slot);
+		reader->last_power_mode = MMC_POWER_OFF;
+		break;
+	case MMC_POWER_UP:
+	default:
+		/* ignore */;
+	}
+
+	cb710_mmc_enable_4bit_data(slot, ios->bus_width != MMC_BUS_WIDTH_1);
+
+	cb710_mmc_enable_irq(slot, CB710_MMC_IE_TEST_MASK, 0);
+}
+
+static int cb710_mmc_get_ro(struct mmc_host *mmc)
+{
+	struct cb710_slot *slot = cb710_mmc_to_slot(mmc);
+
+	return cb710_read_port_8(slot, CB710_MMC_STATUS3_PORT)
+		& CB710_MMC_S3_WRITE_PROTECTED;
+}
+
+static int cb710_mmc_irq_handler(struct cb710_slot *slot)
+{
+	struct mmc_host *mmc = cb710_slot_to_mmc(slot);
+	struct cb710_mmc_reader *reader = mmc_priv(mmc);
+	u32 status, config1, config2, irqen;
+
+	status = cb710_read_port_32(slot, CB710_MMC_STATUS_PORT);
+	irqen = cb710_read_port_32(slot, CB710_MMC_IRQ_ENABLE_PORT);
+	config2 = cb710_read_port_32(slot, CB710_MMC_CONFIGB_PORT);
+	config1 = cb710_read_port_32(slot, CB710_MMC_CONFIG_PORT);
+
+	dev_dbg(cb710_slot_dev(slot), "interrupt; status: %08X, "
+		"ie: %08X, c2: %08X, c1: %08X\n",
+		status, irqen, config2, config1);
+
+	if (status & (CB710_MMC_S1_CARD_CHANGED << 8)) {
+		/* ack the event */
+		cb710_write_port_8(slot, CB710_MMC_STATUS1_PORT,
+			CB710_MMC_S1_CARD_CHANGED);
+		if ((irqen & CB710_MMC_IE_CISTATUS_MASK)
+		    == CB710_MMC_IE_CISTATUS_MASK)
+			mmc_detect_change(mmc, HZ/5);
+	} else {
+		dev_dbg(cb710_slot_dev(slot), "unknown interrupt (test)\n");
+		spin_lock(&reader->irq_lock);
+		__cb710_mmc_enable_irq(slot, 0, CB710_MMC_IE_TEST_MASK);
+		spin_unlock(&reader->irq_lock);
+	}
+
+	return 1;
+}
+
+static void cb710_mmc_finish_request_tasklet(unsigned long data)
+{
+	struct mmc_host *mmc = (void *)data;
+	struct cb710_mmc_reader *reader = mmc_priv(mmc);
+	struct mmc_request *mrq = reader->mrq;
+
+	reader->mrq = NULL;
+	mmc_request_done(mmc, mrq);
+}
+
+static const struct mmc_host_ops cb710_mmc_host = {
+	.request = cb710_mmc_request,
+	.set_ios = cb710_mmc_set_ios,
+	.get_ro = cb710_mmc_get_ro
+};
+
+#ifdef CONFIG_PM
+
+static int cb710_mmc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct cb710_slot *slot = cb710_pdev_to_slot(pdev);
+	struct mmc_host *mmc = cb710_slot_to_mmc(slot);
+	int err;
+
+	err = mmc_suspend_host(mmc, state);
+	if (err)
+		return err;
+
+	cb710_mmc_enable_irq(slot, 0, ~0);
+	return 0;
+}
+
+static int cb710_mmc_resume(struct platform_device *pdev)
+{
+	struct cb710_slot *slot = cb710_pdev_to_slot(pdev);
+	struct mmc_host *mmc = cb710_slot_to_mmc(slot);
+
+	cb710_mmc_enable_irq(slot, 0, ~0);
+
+	return mmc_resume_host(mmc);
+}
+
+#endif /* CONFIG_PM */
+
+static int __devinit cb710_mmc_init(struct platform_device *pdev)
+{
+	struct cb710_slot *slot = cb710_pdev_to_slot(pdev);
+	struct cb710_chip *chip = cb710_slot_to_chip(slot);
+	struct mmc_host *mmc;
+	struct cb710_mmc_reader *reader;
+	int err;
+	u32 val;
+
+	mmc = mmc_alloc_host(sizeof(*reader), cb710_slot_dev(slot));
+	if (!mmc)
+		return -ENOMEM;
+
+	dev_set_drvdata(&pdev->dev, mmc);
+
+	/* harmless (maybe) magic */
+	pci_read_config_dword(chip->pdev, 0x48, &val);
+	val = cb710_src_freq_mhz[(val >> 16) & 0xF];
+	dev_dbg(cb710_slot_dev(slot), "source frequency: %dMHz\n", val);
+	val *= 1000000;
+
+	mmc->ops = &cb710_mmc_host;
+	mmc->f_max = val;
+	mmc->f_min = val >> cb710_clock_divider_log2[CB710_MAX_DIVIDER_IDX];
+	mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34;
+	mmc->caps = MMC_CAP_4_BIT_DATA;
+
+	reader = mmc_priv(mmc);
+
+	tasklet_init(&reader->finish_req_tasklet,
+		cb710_mmc_finish_request_tasklet, (unsigned long)mmc);
+	spin_lock_init(&reader->irq_lock);
+	cb710_dump_regs(chip, CB710_DUMP_REGS_MMC);
+
+	cb710_mmc_enable_irq(slot, 0, ~0);
+	cb710_set_irq_handler(slot, cb710_mmc_irq_handler);
+
+	err = mmc_add_host(mmc);
+	if (unlikely(err))
+		goto err_free_mmc;
+
+	dev_dbg(cb710_slot_dev(slot), "mmc_hostname is %s\n",
+		mmc_hostname(mmc));
+
+	cb710_mmc_enable_irq(slot, CB710_MMC_IE_CARD_INSERTION_STATUS, 0);
+
+	return 0;
+
+err_free_mmc:
+	dev_dbg(cb710_slot_dev(slot), "mmc_add_host() failed: %d\n", err);
+
+	mmc_free_host(mmc);
+	return err;
+}
+
+static int __devexit cb710_mmc_exit(struct platform_device *pdev)
+{
+	struct cb710_slot *slot = cb710_pdev_to_slot(pdev);
+	struct mmc_host *mmc = cb710_slot_to_mmc(slot);
+	struct cb710_mmc_reader *reader = mmc_priv(mmc);
+
+	cb710_mmc_enable_irq(slot, 0, CB710_MMC_IE_CARD_INSERTION_STATUS);
+
+	mmc_remove_host(mmc);
+
+	/* IRQs should be disabled now, but let's stay on the safe side */
+	cb710_mmc_enable_irq(slot, 0, ~0);
+	cb710_set_irq_handler(slot, NULL);
+
+	/* clear config ports - just in case */
+	cb710_write_port_32(slot, CB710_MMC_CONFIG_PORT, 0);
+	cb710_write_port_16(slot, CB710_MMC_CONFIGB_PORT, 0);
+
+	tasklet_kill(&reader->finish_req_tasklet);
+
+	mmc_free_host(mmc);
+	return 0;
+}
+
+static struct platform_driver cb710_mmc_driver = {
+	.driver.name = "cb710-mmc",
+	.probe = cb710_mmc_init,
+	.remove = __devexit_p(cb710_mmc_exit),
+#ifdef CONFIG_PM
+	.suspend = cb710_mmc_suspend,
+	.resume = cb710_mmc_resume,
+#endif
+};
+
+static int __init cb710_mmc_init_module(void)
+{
+	return platform_driver_register(&cb710_mmc_driver);
+}
+
+static void __exit cb710_mmc_cleanup_module(void)
+{
+	platform_driver_unregister(&cb710_mmc_driver);
+}
+
+module_init(cb710_mmc_init_module);
+module_exit(cb710_mmc_cleanup_module);
+
+MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
+MODULE_DESCRIPTION("ENE CB710 memory card reader driver - MMC/SD part");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:cb710-mmc");
diff --git a/drivers/mmc/host/cb710-mmc.h b/drivers/mmc/host/cb710-mmc.h
new file mode 100644
index 0000000..e845c77
--- /dev/null
+++ b/drivers/mmc/host/cb710-mmc.h
@@ -0,0 +1,104 @@
+/*
+ *  cb710/cb710-mmc.h
+ *
+ *  Copyright by Michał Mirosław, 2008-2009
+ *
+ * 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.
+ */
+#ifndef LINUX_CB710_MMC_H
+#define LINUX_CB710_MMC_H
+
+#include <linux/cb710.h>
+
+/* per-MMC-reader structure */
+struct cb710_mmc_reader {
+	struct tasklet_struct finish_req_tasklet;
+	struct mmc_request *mrq;
+	spinlock_t irq_lock;
+	unsigned char last_power_mode;
+};
+
+/* some device struct walking */
+
+static inline struct mmc_host *cb710_slot_to_mmc(struct cb710_slot *slot)
+{
+	return dev_get_drvdata(&slot->pdev.dev);
+}
+
+static inline struct cb710_slot *cb710_mmc_to_slot(struct mmc_host *mmc)
+{
+	struct platform_device *pdev = container_of(mmc_dev(mmc),
+		struct platform_device, dev);
+	return cb710_pdev_to_slot(pdev);
+}
+
+/* registers (this might be all wrong ;) */
+
+#define CB710_MMC_DATA_PORT		0x00
+
+#define CB710_MMC_CONFIG_PORT		0x04
+#define CB710_MMC_CONFIG0_PORT		0x04
+#define CB710_MMC_CONFIG1_PORT		0x05
+#define   CB710_MMC_C1_4BIT_DATA_BUS		0x40
+#define CB710_MMC_CONFIG2_PORT		0x06
+#define   CB710_MMC_C2_READ_PIO_SIZE_MASK	0x0F	/* N-1 */
+#define CB710_MMC_CONFIG3_PORT		0x07
+
+#define CB710_MMC_CONFIGB_PORT		0x08
+
+#define CB710_MMC_IRQ_ENABLE_PORT	0x0C
+#define   CB710_MMC_IE_TEST_MASK		0x00BF
+#define   CB710_MMC_IE_CARD_INSERTION_STATUS	0x1000
+#define   CB710_MMC_IE_IRQ_ENABLE		0x8000
+#define   CB710_MMC_IE_CISTATUS_MASK		\
+		(CB710_MMC_IE_CARD_INSERTION_STATUS|CB710_MMC_IE_IRQ_ENABLE)
+
+#define CB710_MMC_STATUS_PORT		0x10
+#define   CB710_MMC_STATUS_ERROR_EVENTS		0x60FF
+#define CB710_MMC_STATUS0_PORT		0x10
+#define   CB710_MMC_S0_FIFO_UNDERFLOW		0x40
+#define CB710_MMC_STATUS1_PORT		0x11
+#define   CB710_MMC_S1_COMMAND_SENT		0x01
+#define   CB710_MMC_S1_DATA_TRANSFER_DONE	0x02
+#define   CB710_MMC_S1_PIO_TRANSFER_DONE	0x04
+#define   CB710_MMC_S1_CARD_CHANGED		0x10
+#define   CB710_MMC_S1_RESET			0x20
+#define CB710_MMC_STATUS2_PORT		0x12
+#define   CB710_MMC_S2_FIFO_READY		0x01
+#define   CB710_MMC_S2_FIFO_EMPTY		0x02
+#define   CB710_MMC_S2_BUSY_10			0x10
+#define   CB710_MMC_S2_BUSY_20			0x20
+#define CB710_MMC_STATUS3_PORT		0x13
+#define   CB710_MMC_S3_CARD_DETECTED		0x02
+#define   CB710_MMC_S3_WRITE_PROTECTED		0x04
+
+#define CB710_MMC_CMD_TYPE_PORT		0x14
+#define   CB710_MMC_RSP_TYPE_MASK		0x0007
+#define     CB710_MMC_RSP_R1			(0)
+#define     CB710_MMC_RSP_136			(5)
+#define     CB710_MMC_RSP_NO_CRC		(2)
+#define   CB710_MMC_RSP_PRESENT_MASK		0x0018
+#define     CB710_MMC_RSP_NONE			(0 << 3)
+#define     CB710_MMC_RSP_PRESENT		(1 << 3)
+#define     CB710_MMC_RSP_PRESENT_X		(2 << 3)
+#define   CB710_MMC_CMD_TYPE_MASK		0x0060
+#define     CB710_MMC_CMD_BC			(0 << 5)
+#define     CB710_MMC_CMD_BCR			(1 << 5)
+#define     CB710_MMC_CMD_AC			(2 << 5)
+#define     CB710_MMC_CMD_ADTC			(3 << 5)
+#define   CB710_MMC_DATA_READ			0x0080
+#define   CB710_MMC_CMD_CODE_MASK		0x3F00
+#define   CB710_MMC_CMD_CODE_SHIFT		8
+#define   CB710_MMC_IS_APP_CMD			0x4000
+#define   CB710_MMC_RSP_BUSY			0x8000
+
+#define CB710_MMC_CMD_PARAM_PORT	0x18
+#define CB710_MMC_TRANSFER_SIZE_PORT	0x1C
+#define CB710_MMC_RESPONSE0_PORT	0x20
+#define CB710_MMC_RESPONSE1_PORT	0x24
+#define CB710_MMC_RESPONSE2_PORT	0x28
+#define CB710_MMC_RESPONSE3_PORT	0x2C
+
+#endif /* LINUX_CB710_MMC_H */