memstick: add driver for Ricoh R5C592 card reader

Signed-off-by: Maxim Levitsky <[e-mail]>
Acked-by: Alex Dubov <[e-mail]>
Cc: FUJITA Tomonori <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

MAINTAINERS

···
 F:	drivers/mtd/nand/r852.c
 F:	drivers/mtd/nand/r852.h
 
+RICOH R5C592 MEMORYSTICK DRIVER
+M:	Maxim Levitsky <[e-mail]>
+S:	Maintained
+F:	drivers/memstick/host/r592.*
+
 RISCOM8 DRIVER
 S:	Orphan
 F:	Documentation/serial/riscom8.txt

drivers/memstick/host/Kconfig

···
 
           To compile this driver as a module, choose M here: the
 	  module will be called jmb38x_ms.
+
+config MEMSTICK_R592
+	tristate "Ricoh R5C592 MemoryStick interface support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL && PCI
+
+	help
+	  Say Y here if you want to be able to access MemoryStick cards with
+	  the Ricoh R5C592 MemoryStick card reader (which is part of 5 in one
+		multifunction reader)
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called r592.

drivers/memstick/host/Makefile

···
 
 obj-$(CONFIG_MEMSTICK_TIFM_MS)		+= tifm_ms.o
 obj-$(CONFIG_MEMSTICK_JMICRON_38X)	+= jmb38x_ms.o
+obj-$(CONFIG_MEMSTICK_R592)		+= r592.o

drivers/memstick/host/r592.c

···
+/*
+ * Copyright (C) 2010 - Maxim Levitsky
+ * driver for Ricoh memstick readers
+ *
+ * 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/freezer.h>
+#include <linux/jiffies.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/sched.h>
+#include <linux/highmem.h>
+#include <asm/byteorder.h>
+#include <linux/swab.h>
+#include "r592.h"
+
+static int enable_dma = 1;
+static int debug;
+
+static const char *tpc_names[] = {
+	"MS_TPC_READ_MG_STATUS",
+	"MS_TPC_READ_LONG_DATA",
+	"MS_TPC_READ_SHORT_DATA",
+	"MS_TPC_READ_REG",
+	"MS_TPC_READ_QUAD_DATA",
+	"INVALID",
+	"MS_TPC_GET_INT",
+	"MS_TPC_SET_RW_REG_ADRS",
+	"MS_TPC_EX_SET_CMD",
+	"MS_TPC_WRITE_QUAD_DATA",
+	"MS_TPC_WRITE_REG",
+	"MS_TPC_WRITE_SHORT_DATA",
+	"MS_TPC_WRITE_LONG_DATA",
+	"MS_TPC_SET_CMD",
+};
+
+/**
+ * memstick_debug_get_tpc_name - debug helper that returns string for
+ * a TPC number
+ */
+const char *memstick_debug_get_tpc_name(int tpc)
+{
+	return tpc_names[tpc-1];
+}
+EXPORT_SYMBOL(memstick_debug_get_tpc_name);
+
+
+/* Read a register*/
+static inline u32 r592_read_reg(struct r592_device *dev, int address)
+{
+	u32 value = readl(dev->mmio + address);
+	dbg_reg("reg #%02d == 0x%08x", address, value);
+	return value;
+}
+
+/* Write a register */
+static inline void r592_write_reg(struct r592_device *dev,
+							int address, u32 value)
+{
+	dbg_reg("reg #%02d <- 0x%08x", address, value);
+	writel(value, dev->mmio + address);
+}
+
+/* Reads a big endian DWORD register */
+static inline u32 r592_read_reg_raw_be(struct r592_device *dev, int address)
+{
+	u32 value = __raw_readl(dev->mmio + address);
+	dbg_reg("reg #%02d == 0x%08x", address, value);
+	return be32_to_cpu(value);
+}
+
+/* Writes a big endian DWORD register */
+static inline void r592_write_reg_raw_be(struct r592_device *dev,
+							int address, u32 value)
+{
+	dbg_reg("reg #%02d <- 0x%08x", address, value);
+	__raw_writel(cpu_to_be32(value), dev->mmio + address);
+}
+
+/* Set specific bits in a register (little endian) */
+static inline void r592_set_reg_mask(struct r592_device *dev,
+							int address, u32 mask)
+{
+	u32 reg = readl(dev->mmio + address);
+	dbg_reg("reg #%02d |= 0x%08x (old =0x%08x)", address, mask, reg);
+	writel(reg | mask , dev->mmio + address);
+}
+
+/* Clear specific bits in a register (little endian) */
+static inline void r592_clear_reg_mask(struct r592_device *dev,
+						int address, u32 mask)
+{
+	u32 reg = readl(dev->mmio + address);
+	dbg_reg("reg #%02d &= 0x%08x (old = 0x%08x, mask = 0x%08x)",
+						address, ~mask, reg, mask);
+	writel(reg & ~mask, dev->mmio + address);
+}
+
+
+/* Wait for status bits while checking for errors */
+static int r592_wait_status(struct r592_device *dev, u32 mask, u32 wanted_mask)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+	u32 reg = r592_read_reg(dev, R592_STATUS);
+
+	if ((reg & mask) == wanted_mask)
+		return 0;
+
+	while (time_before(jiffies, timeout)) {
+
+		reg = r592_read_reg(dev, R592_STATUS);
+
+		if ((reg & mask) == wanted_mask)
+			return 0;
+
+		if (reg & (R592_STATUS_SEND_ERR | R592_STATUS_RECV_ERR))
+			return -EIO;
+
+		cpu_relax();
+	}
+	return -ETIME;
+}
+
+
+/* Enable/disable device */
+static int r592_enable_device(struct r592_device *dev, bool enable)
+{
+	dbg("%sabling the device", enable ? "en" : "dis");
+
+	if (enable) {
+
+		/* Power up the card */
+		r592_write_reg(dev, R592_POWER, R592_POWER_0 | R592_POWER_1);
+
+		/* Perform a reset */
+		r592_set_reg_mask(dev, R592_IO, R592_IO_RESET);
+
+		msleep(100);
+	} else
+		/* Power down the card */
+		r592_write_reg(dev, R592_POWER, 0);
+
+	return 0;
+}
+
+/* Set serial/parallel mode */
+static int r592_set_mode(struct r592_device *dev, bool parallel_mode)
+{
+	if (!parallel_mode) {
+		dbg("switching to serial mode");
+
+		/* Set serial mode */
+		r592_write_reg(dev, R592_IO_MODE, R592_IO_MODE_SERIAL);
+
+		r592_clear_reg_mask(dev, R592_POWER, R592_POWER_20);
+
+	} else {
+		dbg("switching to parallel mode");
+
+		/* This setting should be set _before_ switch TPC */
+		r592_set_reg_mask(dev, R592_POWER, R592_POWER_20);
+
+		r592_clear_reg_mask(dev, R592_IO,
+			R592_IO_SERIAL1 | R592_IO_SERIAL2);
+
+		/* Set the parallel mode now */
+		r592_write_reg(dev, R592_IO_MODE, R592_IO_MODE_PARALLEL);
+	}
+
+	dev->parallel_mode = parallel_mode;
+	return 0;
+}
+
+/* Perform a controller reset without powering down the card */
+static void r592_host_reset(struct r592_device *dev)
+{
+	r592_set_reg_mask(dev, R592_IO, R592_IO_RESET);
+	msleep(100);
+	r592_set_mode(dev, dev->parallel_mode);
+}
+
+/* Disable all hardware interrupts */
+static void r592_clear_interrupts(struct r592_device *dev)
+{
+	/* Disable & ACK all interrupts */
+	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_ACK_MASK);
+	r592_clear_reg_mask(dev, R592_REG_MSC, IRQ_ALL_EN_MASK);
+}
+
+/* Tests if there is an CRC error */
+static int r592_test_io_error(struct r592_device *dev)
+{
+	if (!(r592_read_reg(dev, R592_STATUS) &
+		(R592_STATUS_SEND_ERR | R592_STATUS_RECV_ERR)))
+		return 0;
+
+	return -EIO;
+}
+
+/* Ensure that FIFO is ready for use */
+static int r592_test_fifo_empty(struct r592_device *dev)
+{
+	if (r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_FIFO_EMPTY)
+		return 0;
+
+	dbg("FIFO not ready, trying to reset the device");
+	r592_host_reset(dev);
+
+	if (r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_FIFO_EMPTY)
+		return 0;
+
+	message("FIFO still not ready, giving up");
+	return -EIO;
+}
+
+/* Activates the DMA transfer from to FIFO */
+static void r592_start_dma(struct r592_device *dev, bool is_write)
+{
+	unsigned long flags;
+	u32 reg;
+	spin_lock_irqsave(&dev->irq_lock, flags);
+
+	/* Ack interrupts (just in case) + enable them */
+	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_ACK_MASK);
+	r592_set_reg_mask(dev, R592_REG_MSC, DMA_IRQ_EN_MASK);
+
+	/* Set DMA address */
+	r592_write_reg(dev, R592_FIFO_DMA, sg_dma_address(&dev->req->sg));
+
+	/* Enable the DMA */
+	reg = r592_read_reg(dev, R592_FIFO_DMA_SETTINGS);
+	reg |= R592_FIFO_DMA_SETTINGS_EN;
+
+	if (!is_write)
+		reg |= R592_FIFO_DMA_SETTINGS_DIR;
+	else
+		reg &= ~R592_FIFO_DMA_SETTINGS_DIR;
+	r592_write_reg(dev, R592_FIFO_DMA_SETTINGS, reg);
+
+	spin_unlock_irqrestore(&dev->irq_lock, flags);
+}
+
+/* Cleanups DMA related settings */
+static void r592_stop_dma(struct r592_device *dev, int error)
+{
+	r592_clear_reg_mask(dev, R592_FIFO_DMA_SETTINGS,
+		R592_FIFO_DMA_SETTINGS_EN);
+
+	/* This is only a precation */
+	r592_write_reg(dev, R592_FIFO_DMA,
+			dev->dummy_dma_page_physical_address);
+
+	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_EN_MASK);
+	r592_clear_reg_mask(dev, R592_REG_MSC, DMA_IRQ_ACK_MASK);
+	dev->dma_error = error;
+}
+
+/* Test if hardware supports DMA */
+static void r592_check_dma(struct r592_device *dev)
+{
+	dev->dma_capable = enable_dma &&
+		(r592_read_reg(dev, R592_FIFO_DMA_SETTINGS) &
+			R592_FIFO_DMA_SETTINGS_CAP);
+}
+
+/* Transfers fifo contents in/out using DMA */
+static int r592_transfer_fifo_dma(struct r592_device *dev)
+{
+	int len, sg_count;
+	bool is_write;
+
+	if (!dev->dma_capable || !dev->req->long_data)
+		return -EINVAL;
+
+	len = dev->req->sg.length;
+	is_write = dev->req->data_dir == WRITE;
+
+	if (len != R592_LFIFO_SIZE)
+		return -EINVAL;
+
+	dbg_verbose("doing dma transfer");
+
+	dev->dma_error = 0;
+	INIT_COMPLETION(dev->dma_done);
+
+	/* TODO: hidden assumption about nenth beeing always 1 */
+	sg_count = dma_map_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ?
+		PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
+
+	if (sg_count != 1 ||
+			(sg_dma_len(&dev->req->sg) < dev->req->sg.length)) {
+		message("problem in dma_map_sg");
+		return -EIO;
+	}
+
+	r592_start_dma(dev, is_write);
+
+	/* Wait for DMA completion */
+	if (!wait_for_completion_timeout(
+			&dev->dma_done, msecs_to_jiffies(1000))) {
+		message("DMA timeout");
+		r592_stop_dma(dev, -ETIMEDOUT);
+	}
+
+	dma_unmap_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ?
+		PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
+
+
+	return dev->dma_error;
+}
+
+/*
+ * Writes the FIFO in 4 byte chunks.
+ * If length isn't 4 byte aligned, rest of the data if put to a fifo
+ * to be written later
+ * Use r592_flush_fifo_write to flush that fifo when writing for the
+ * last time
+ */
+static void r592_write_fifo_pio(struct r592_device *dev,
+					unsigned char *buffer, int len)
+{
+	/* flush spill from former write */
+	if (!kfifo_is_empty(&dev->pio_fifo)) {
+
+		u8 tmp[4] = {0};
+		int copy_len = kfifo_in(&dev->pio_fifo, buffer, len);
+
+		if (!kfifo_is_full(&dev->pio_fifo))
+			return;
+		len -= copy_len;
+		buffer += copy_len;
+
+		copy_len = kfifo_out(&dev->pio_fifo, tmp, 4);
+		WARN_ON(copy_len != 4);
+		r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)tmp);
+	}
+
+	WARN_ON(!kfifo_is_empty(&dev->pio_fifo));
+
+	/* write full dwords */
+	while (len >= 4) {
+		r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)buffer);
+		buffer += 4;
+		len -= 4;
+	}
+
+	/* put remaining bytes to the spill */
+	if (len)
+		kfifo_in(&dev->pio_fifo, buffer, len);
+}
+
+/* Flushes the temporary FIFO used to make aligned DWORD writes */
+static void r592_flush_fifo_write(struct r592_device *dev)
+{
+	u8 buffer[4] = { 0 };
+	int len;
+
+	if (kfifo_is_empty(&dev->pio_fifo))
+		return;
+
+	len = kfifo_out(&dev->pio_fifo, buffer, 4);
+	r592_write_reg_raw_be(dev, R592_FIFO_PIO, *(u32 *)buffer);
+}
+
+/*
+ * Read a fifo in 4 bytes chunks.
+ * If input doesn't fit the buffer, it places bytes of last dword in spill
+ * buffer, so that they don't get lost on last read, just throw these away.
+ */
+static void r592_read_fifo_pio(struct r592_device *dev,
+						unsigned char *buffer, int len)
+{
+	u8 tmp[4];
+
+	/* Read from last spill */
+	if (!kfifo_is_empty(&dev->pio_fifo)) {
+		int bytes_copied =
+			kfifo_out(&dev->pio_fifo, buffer, min(4, len));
+		buffer += bytes_copied;
+		len -= bytes_copied;
+
+		if (!kfifo_is_empty(&dev->pio_fifo))
+			return;
+	}
+
+	/* Reads dwords from FIFO */
+	while (len >= 4) {
+		*(u32 *)buffer = r592_read_reg_raw_be(dev, R592_FIFO_PIO);
+		buffer += 4;
+		len -= 4;
+	}
+
+	if (len) {
+		*(u32 *)tmp = r592_read_reg_raw_be(dev, R592_FIFO_PIO);
+		kfifo_in(&dev->pio_fifo, tmp, 4);
+		len -= kfifo_out(&dev->pio_fifo, buffer, len);
+	}
+
+	WARN_ON(len);
+	return;
+}
+
+/* Transfers actual data using PIO. */
+static int r592_transfer_fifo_pio(struct r592_device *dev)
+{
+	unsigned long flags;
+
+	bool is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
+	struct sg_mapping_iter miter;
+
+	kfifo_reset(&dev->pio_fifo);
+
+	if (!dev->req->long_data) {
+		if (is_write) {
+			r592_write_fifo_pio(dev, dev->req->data,
+							dev->req->data_len);
+			r592_flush_fifo_write(dev);
+		} else
+			r592_read_fifo_pio(dev, dev->req->data,
+							dev->req->data_len);
+		return 0;
+	}
+
+	local_irq_save(flags);
+	sg_miter_start(&miter, &dev->req->sg, 1, SG_MITER_ATOMIC |
+		(is_write ? SG_MITER_FROM_SG : SG_MITER_TO_SG));
+
+	/* Do the transfer fifo<->memory*/
+	while (sg_miter_next(&miter))
+		if (is_write)
+			r592_write_fifo_pio(dev, miter.addr, miter.length);
+		else
+			r592_read_fifo_pio(dev, miter.addr, miter.length);
+
+
+	/* Write last few non aligned bytes*/
+	if (is_write)
+		r592_flush_fifo_write(dev);
+
+	sg_miter_stop(&miter);
+	local_irq_restore(flags);
+	return 0;
+}
+
+/* Executes one TPC (data is read/written from small or large fifo) */
+static void r592_execute_tpc(struct r592_device *dev)
+{
+	bool is_write = dev->req->tpc >= MS_TPC_SET_RW_REG_ADRS;
+	int len, error;
+	u32 status, reg;
+
+	if (!dev->req) {
+		message("BUG: tpc execution without request!");
+		return;
+	}
+
+	len = dev->req->long_data ?
+		dev->req->sg.length : dev->req->data_len;
+
+	/* Ensure that FIFO can hold the input data */
+	if (len > R592_LFIFO_SIZE) {
+		message("IO: hardware doesn't support TPCs longer that 512");
+		error = -ENOSYS;
+		goto out;
+	}
+
+	if (!(r592_read_reg(dev, R592_REG_MSC) & R592_REG_MSC_PRSNT)) {
+		dbg("IO: refusing to send TPC because card is absent");
+		error = -ENODEV;
+		goto out;
+	}
+
+	dbg("IO: executing %s LEN=%d",
+			memstick_debug_get_tpc_name(dev->req->tpc), len);
+
+	/* Set IO direction */
+	if (is_write)
+		r592_set_reg_mask(dev, R592_IO, R592_IO_DIRECTION);
+	else
+		r592_clear_reg_mask(dev, R592_IO, R592_IO_DIRECTION);
+
+
+	error = r592_test_fifo_empty(dev);
+	if (error)
+		goto out;
+
+	/* Transfer write data */
+	if (is_write) {
+		error = r592_transfer_fifo_dma(dev);
+		if (error == -EINVAL)
+			error = r592_transfer_fifo_pio(dev);
+	}
+
+	if (error)
+		goto out;
+
+	/* Trigger the TPC */
+	reg = (len << R592_TPC_EXEC_LEN_SHIFT) |
+		(dev->req->tpc << R592_TPC_EXEC_TPC_SHIFT) |
+			R592_TPC_EXEC_BIG_FIFO;
+
+	r592_write_reg(dev, R592_TPC_EXEC, reg);
+
+	/* Wait for TPC completion */
+	status = R592_STATUS_RDY;
+	if (dev->req->need_card_int)
+		status |= R592_STATUS_CED;
+
+	error = r592_wait_status(dev, status, status);
+	if (error) {
+		message("card didn't respond");
+		goto out;
+	}
+
+	/* Test IO errors */
+	error = r592_test_io_error(dev);
+	if (error) {
+		dbg("IO error");
+		goto out;
+	}
+
+	/* Read data from FIFO */
+	if (!is_write) {
+		error = r592_transfer_fifo_dma(dev);
+		if (error == -EINVAL)
+			error = r592_transfer_fifo_pio(dev);
+	}
+
+	/* read INT reg. This can be shortened with shifts, but that way
+		its more readable */
+	if (dev->parallel_mode && dev->req->need_card_int) {
+
+		dev->req->int_reg = 0;
+		status = r592_read_reg(dev, R592_STATUS);
+
+		if (status & R592_STATUS_P_CMDNACK)
+			dev->req->int_reg |= MEMSTICK_INT_CMDNAK;
+		if (status & R592_STATUS_P_BREQ)
+			dev->req->int_reg |= MEMSTICK_INT_BREQ;
+		if (status & R592_STATUS_P_INTERR)
+			dev->req->int_reg |= MEMSTICK_INT_ERR;
+		if (status & R592_STATUS_P_CED)
+			dev->req->int_reg |= MEMSTICK_INT_CED;
+	}
+
+	if (error)
+		dbg("FIFO read error");
+out:
+	dev->req->error = error;
+	r592_clear_reg_mask(dev, R592_REG_MSC, R592_REG_MSC_LED);
+	return;
+}
+
+/* Main request processing thread */
+static int r592_process_thread(void *data)
+{
+	int error;
+	struct r592_device *dev = (struct r592_device *)data;
+	unsigned long flags;
+
+	while (!kthread_should_stop()) {
+		spin_lock_irqsave(&dev->io_thread_lock, flags);
+		set_current_state(TASK_INTERRUPTIBLE);
+		error = memstick_next_req(dev->host, &dev->req);
+		spin_unlock_irqrestore(&dev->io_thread_lock, flags);
+
+		if (error) {
+			if (error == -ENXIO || error == -EAGAIN) {
+				dbg_verbose("IO: done IO, sleeping");
+			} else {
+				dbg("IO: unknown error from "
+					"memstick_next_req %d", error);
+			}
+
+			if (kthread_should_stop())
+				set_current_state(TASK_RUNNING);
+
+			schedule();
+		} else {
+			set_current_state(TASK_RUNNING);
+			r592_execute_tpc(dev);
+		}
+	}
+	return 0;
+}
+
+/* Reprogram chip to detect change in card state */
+/* eg, if card is detected, arm it to detect removal, and vice versa */
+static void r592_update_card_detect(struct r592_device *dev)
+{
+	u32 reg = r592_read_reg(dev, R592_REG_MSC);
+	bool card_detected = reg & R592_REG_MSC_PRSNT;
+
+	dbg("update card detect. card state: %s", card_detected ?
+		"present" : "absent");
+
+	reg &= ~((R592_REG_MSC_IRQ_REMOVE | R592_REG_MSC_IRQ_INSERT) << 16);
+
+	if (card_detected)
+		reg |= (R592_REG_MSC_IRQ_REMOVE << 16);
+	else
+		reg |= (R592_REG_MSC_IRQ_INSERT << 16);
+
+	r592_write_reg(dev, R592_REG_MSC, reg);
+}
+
+/* Timer routine that fires 1 second after last card detection event, */
+static void r592_detect_timer(long unsigned int data)
+{
+	struct r592_device *dev = (struct r592_device *)data;
+	r592_update_card_detect(dev);
+	memstick_detect_change(dev->host);
+}
+
+/* Interrupt handler */
+static irqreturn_t r592_irq(int irq, void *data)
+{
+	struct r592_device *dev = (struct r592_device *)data;
+	irqreturn_t ret = IRQ_NONE;
+	u32 reg;
+	u16 irq_enable, irq_status;
+	unsigned long flags;
+	int error;
+
+	spin_lock_irqsave(&dev->irq_lock, flags);
+
+	reg = r592_read_reg(dev, R592_REG_MSC);
+	irq_enable = reg >> 16;
+	irq_status = reg & 0xFFFF;
+
+	/* Ack the interrupts */
+	reg &= ~irq_status;
+	r592_write_reg(dev, R592_REG_MSC, reg);
+
+	/* Get the IRQ status minus bits that aren't enabled */
+	irq_status &= (irq_enable);
+
+	/* Due to limitation of memstick core, we don't look at bits that
+		indicate that card was removed/inserted and/or present */
+	if (irq_status & (R592_REG_MSC_IRQ_INSERT | R592_REG_MSC_IRQ_REMOVE)) {
+
+		bool card_was_added = irq_status & R592_REG_MSC_IRQ_INSERT;
+		ret = IRQ_HANDLED;
+
+		message("IRQ: card %s", card_was_added ? "added" : "removed");
+
+		mod_timer(&dev->detect_timer,
+			jiffies + msecs_to_jiffies(card_was_added ? 500 : 50));
+	}
+
+	if (irq_status &
+		(R592_REG_MSC_FIFO_DMA_DONE | R592_REG_MSC_FIFO_DMA_ERR)) {
+		ret = IRQ_HANDLED;
+
+		if (irq_status & R592_REG_MSC_FIFO_DMA_ERR) {
+			message("IRQ: DMA error");
+			error = -EIO;
+		} else {
+			dbg_verbose("IRQ: dma done");
+			error = 0;
+		}
+
+		r592_stop_dma(dev, error);
+		complete(&dev->dma_done);
+	}
+
+	spin_unlock_irqrestore(&dev->irq_lock, flags);
+	return ret;
+}
+
+/* External inteface: set settings */
+static int r592_set_param(struct memstick_host *host,
+			enum memstick_param param, int value)
+{
+	struct r592_device *dev = memstick_priv(host);
+
+	switch (param) {
+	case MEMSTICK_POWER:
+		switch (value) {
+		case MEMSTICK_POWER_ON:
+			return r592_enable_device(dev, true);
+		case MEMSTICK_POWER_OFF:
+			return r592_enable_device(dev, false);
+		default:
+			return -EINVAL;
+		}
+	case MEMSTICK_INTERFACE:
+		switch (value) {
+		case MEMSTICK_SERIAL:
+			return r592_set_mode(dev, 0);
+		case MEMSTICK_PAR4:
+			return r592_set_mode(dev, 1);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+/* External interface: submit requests */
+static void r592_submit_req(struct memstick_host *host)
+{
+	struct r592_device *dev = memstick_priv(host);
+	unsigned long flags;
+
+	if (dev->req)
+		return;
+
+	spin_lock_irqsave(&dev->io_thread_lock, flags);
+	if (wake_up_process(dev->io_thread))
+		dbg_verbose("IO thread woken to process requests");
+	spin_unlock_irqrestore(&dev->io_thread_lock, flags);
+}
+
+static const struct pci_device_id r592_pci_id_tbl[] = {
+
+	{ PCI_VDEVICE(RICOH, 0x0592), },
+	{ },
+};
+
+/* Main entry */
+static int r592_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	int error = -ENOMEM;
+	struct memstick_host *host;
+	struct r592_device *dev;
+
+	/* Allocate memory */
+	host = memstick_alloc_host(sizeof(struct r592_device), &pdev->dev);
+	if (!host)
+		goto error1;
+
+	dev = memstick_priv(host);
+	dev->host = host;
+	dev->pci_dev = pdev;
+	pci_set_drvdata(pdev, dev);
+
+	/* pci initialization */
+	error = pci_enable_device(pdev);
+	if (error)
+		goto error2;
+
+	pci_set_master(pdev);
+	error = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+	if (error)
+		goto error3;
+
+	error = pci_request_regions(pdev, DRV_NAME);
+	if (error)
+		goto error3;
+
+	dev->mmio = pci_ioremap_bar(pdev, 0);
+	if (!dev->mmio)
+		goto error4;
+
+	dev->irq = pdev->irq;
+	spin_lock_init(&dev->irq_lock);
+	spin_lock_init(&dev->io_thread_lock);
+	init_completion(&dev->dma_done);
+	INIT_KFIFO(dev->pio_fifo);
+	setup_timer(&dev->detect_timer,
+		r592_detect_timer, (long unsigned int)dev);
+
+	/* Host initialization */
+	host->caps = MEMSTICK_CAP_PAR4;
+	host->request = r592_submit_req;
+	host->set_param = r592_set_param;
+	r592_check_dma(dev);
+
+	dev->io_thread = kthread_run(r592_process_thread, dev, "r592_io");
+	if (IS_ERR(dev->io_thread)) {
+		error = PTR_ERR(dev->io_thread);
+		goto error5;
+	}
+
+	/* This is just a precation, so don't fail */
+	dev->dummy_dma_page = pci_alloc_consistent(pdev, PAGE_SIZE,
+		&dev->dummy_dma_page_physical_address);
+	r592_stop_dma(dev , 0);
+
+	if (request_irq(dev->irq, &r592_irq, IRQF_SHARED,
+			  DRV_NAME, dev))
+		goto error6;
+
+	r592_update_card_detect(dev);
+	if (memstick_add_host(host))
+		goto error7;
+
+	message("driver succesfully loaded");
+	return 0;
+error7:
+	free_irq(dev->irq, dev);
+error6:
+	if (dev->dummy_dma_page)
+		pci_free_consistent(pdev, PAGE_SIZE, dev->dummy_dma_page,
+			dev->dummy_dma_page_physical_address);
+
+	kthread_stop(dev->io_thread);
+error5:
+	iounmap(dev->mmio);
+error4:
+	pci_release_regions(pdev);
+error3:
+	pci_disable_device(pdev);
+error2:
+	memstick_free_host(host);
+error1:
+	return error;
+}
+
+static void r592_remove(struct pci_dev *pdev)
+{
+	int error = 0;
+	struct r592_device *dev = pci_get_drvdata(pdev);
+
+	/* Stop the processing thread.
+	That ensures that we won't take any more requests */
+	kthread_stop(dev->io_thread);
+
+	r592_enable_device(dev, false);
+
+	while (!error && dev->req) {
+		dev->req->error = -ETIME;
+		error = memstick_next_req(dev->host, &dev->req);
+	}
+	memstick_remove_host(dev->host);
+
+	free_irq(dev->irq, dev);
+	iounmap(dev->mmio);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	memstick_free_host(dev->host);
+
+	if (dev->dummy_dma_page)
+		pci_free_consistent(pdev, PAGE_SIZE, dev->dummy_dma_page,
+			dev->dummy_dma_page_physical_address);
+}
+
+#ifdef CONFIG_PM
+static int r592_suspend(struct device *core_dev)
+{
+	struct pci_dev *pdev = to_pci_dev(core_dev);
+	struct r592_device *dev = pci_get_drvdata(pdev);
+
+	r592_clear_interrupts(dev);
+	memstick_suspend_host(dev->host);
+	del_timer_sync(&dev->detect_timer);
+	return 0;
+}
+
+static int r592_resume(struct device *core_dev)
+{
+	struct pci_dev *pdev = to_pci_dev(core_dev);
+	struct r592_device *dev = pci_get_drvdata(pdev);
+
+	r592_clear_interrupts(dev);
+	r592_enable_device(dev, false);
+	memstick_resume_host(dev->host);
+	r592_update_card_detect(dev);
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(r592_pm_ops, r592_suspend, r592_resume);
+#endif
+
+MODULE_DEVICE_TABLE(pci, r592_pci_id_tbl);
+
+static struct pci_driver r852_pci_driver = {
+	.name		= DRV_NAME,
+	.id_table	= r592_pci_id_tbl,
+	.probe		= r592_probe,
+	.remove		= r592_remove,
+#ifdef CONFIG_PM
+	.driver.pm	= &r592_pm_ops,
+#endif
+};
+
+static __init int r592_module_init(void)
+{
+	return pci_register_driver(&r852_pci_driver);
+}
+
+static void __exit r592_module_exit(void)
+{
+	pci_unregister_driver(&r852_pci_driver);
+}
+
+module_init(r592_module_init);
+module_exit(r592_module_exit);
+
+module_param(enable_dma, bool, S_IRUGO);
+MODULE_PARM_DESC(enable_dma, "Enable usage of the DMA (default)");
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug level (0-3)");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Maxim Levitsky <[e-mail]>");
+MODULE_DESCRIPTION("Ricoh R5C592 Memstick/Memstick PRO card reader driver");

drivers/memstick/host/r592.h

···
+/*
+ * Copyright (C) 2010 - Maxim Levitsky
+ * driver for Ricoh memstick readers
+ *
+ * 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 R592_H
+
+#include <linux/memstick.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/kfifo.h>
+#include <linux/ctype.h>
+
+/* write to this reg (number,len) triggers TPC execution */
+#define R592_TPC_EXEC			0x00
+#define R592_TPC_EXEC_LEN_SHIFT		16		/* Bits 16..25 are TPC len */
+#define R592_TPC_EXEC_BIG_FIFO		(1 << 26)	/* If bit 26 is set, large fifo is used (reg 48) */
+#define R592_TPC_EXEC_TPC_SHIFT		28		/* Bits 28..31 are the TPC number */
+
+
+/* Window for small TPC fifo (big endian)*/
+/* reads and writes always are done in  8 byte chunks */
+/* Not used in driver, because large fifo does better job */
+#define R592_SFIFO			0x08
+
+
+/* Status register (ms int, small fifo, IO)*/
+#define R592_STATUS			0x10
+							/* Parallel INT bits */
+#define R592_STATUS_P_CMDNACK		(1 << 16)	/* INT reg: NACK (parallel mode) */
+#define R592_STATUS_P_BREQ		(1 << 17)	/* INT reg: card ready (parallel mode)*/
+#define R592_STATUS_P_INTERR		(1 << 18)	/* INT reg: int error (parallel mode)*/
+#define R592_STATUS_P_CED		(1 << 19)	/* INT reg: command done (parallel mode) */
+
+							/* Fifo status */
+#define R592_STATUS_SFIFO_FULL		(1 << 20)	/* Small Fifo almost full (last chunk is written) */
+#define R592_STATUS_SFIFO_EMPTY		(1 << 21)	/* Small Fifo empty */
+
+							/* Error detection via CRC */
+#define R592_STATUS_SEND_ERR		(1 << 24)	/* Send failed */
+#define R592_STATUS_RECV_ERR		(1 << 25)	/* Recieve failed */
+
+							/* Card state */
+#define R592_STATUS_RDY			(1 << 28)	/* RDY signal recieved */
+#define R592_STATUS_CED			(1 << 29)	/* INT: Command done (serial mode)*/
+#define R592_STATUS_SFIFO_INPUT		(1 << 30)	/* Small fifo recieved data*/
+
+#define R592_SFIFO_SIZE			32		/* total size of small fifo is 32 bytes */
+#define R592_SFIFO_PACKET		8		/* packet size of small fifo */
+
+/* IO control */
+#define R592_IO				0x18
+#define	R592_IO_16			(1 << 16)	/* Set by default, can be cleared */
+#define	R592_IO_18			(1 << 18)	/* Set by default, can be cleared */
+#define	R592_IO_SERIAL1			(1 << 20)	/* Set by default, can be cleared, (cleared on parallel) */
+#define	R592_IO_22			(1 << 22)	/* Set by default, can be cleared */
+#define R592_IO_DIRECTION		(1 << 24)	/* TPC direction (1 write 0 read) */
+#define	R592_IO_26			(1 << 26)	/* Set by default, can be cleared */
+#define	R592_IO_SERIAL2			(1 << 30)	/* Set by default, can be cleared (cleared on parallel), serial doesn't work if unset */
+#define R592_IO_RESET			(1 << 31)	/* Reset, sets defaults*/
+
+
+/* Turns hardware on/off */
+#define R592_POWER			0x20		/* bits 0-7 writeable */
+#define R592_POWER_0			(1 << 0)	/* set on start, cleared on stop - must be set*/
+#define R592_POWER_1			(1 << 1)	/* set on start, cleared on stop - must be set*/
+#define R592_POWER_3			(1 << 3)	/* must be clear */
+#define R592_POWER_20			(1 << 5)	/* set before switch to parallel */
+
+/* IO mode*/
+#define R592_IO_MODE			0x24
+#define R592_IO_MODE_SERIAL		1
+#define R592_IO_MODE_PARALLEL		3
+
+
+/* IRQ,card detection,large fifo (first word irq status, second enable) */
+/* IRQs are ACKed by clearing the bits */
+#define R592_REG_MSC			0x28
+#define R592_REG_MSC_PRSNT		(1 << 1)	/* card present (only status)*/
+#define R592_REG_MSC_IRQ_INSERT		(1 << 8)	/* detect insert / card insered */
+#define R592_REG_MSC_IRQ_REMOVE		(1 << 9)	/* detect removal / card removed */
+#define R592_REG_MSC_FIFO_EMPTY		(1 << 10)	/* fifo is empty */
+#define R592_REG_MSC_FIFO_DMA_DONE	(1 << 11)	/* dma enable / dma done */
+
+#define R592_REG_MSC_FIFO_USER_ORN	(1 << 12)	/* set if software reads empty fifo (if R592_REG_MSC_FIFO_EMPTY is set) */
+#define R592_REG_MSC_FIFO_MISMATH	(1 << 13)	/* set if amount of data in fifo doesn't match amount in TPC */
+#define R592_REG_MSC_FIFO_DMA_ERR	(1 << 14)	/* IO failure */
+#define R592_REG_MSC_LED		(1 << 15)	/* clear to turn led off (only status)*/
+
+#define DMA_IRQ_ACK_MASK \
+	(R592_REG_MSC_FIFO_DMA_DONE | R592_REG_MSC_FIFO_DMA_ERR)
+
+#define DMA_IRQ_EN_MASK (DMA_IRQ_ACK_MASK << 16)
+
+#define IRQ_ALL_ACK_MASK 0x00007F00
+#define IRQ_ALL_EN_MASK (IRQ_ALL_ACK_MASK << 16)
+
+/* DMA address for large FIFO read/writes*/
+#define R592_FIFO_DMA			0x2C
+
+/* PIO access to large FIFO (512 bytes) (big endian)*/
+#define R592_FIFO_PIO			0x30
+#define R592_LFIFO_SIZE			512		/* large fifo size */
+
+
+/* large FIFO DMA settings */
+#define R592_FIFO_DMA_SETTINGS		0x34
+#define R592_FIFO_DMA_SETTINGS_EN	(1 << 0)	/* DMA enabled */
+#define R592_FIFO_DMA_SETTINGS_DIR	(1 << 1)	/* Dma direction (1 read, 0 write) */
+#define R592_FIFO_DMA_SETTINGS_CAP	(1 << 24)	/* Dma is aviable */
+
+/* Maybe just an delay */
+/* Bits 17..19 are just number */
+/* bit 16 is set, then bit 20 is waited */
+/* time to wait is about 50 spins * 2 ^ (bits 17..19) */
+/* seems to be possible just to ignore */
+/* Probably debug register */
+#define R592_REG38			0x38
+#define R592_REG38_CHANGE		(1 << 16)	/* Start bit */
+#define R592_REG38_DONE			(1 << 20)	/* HW set this after the delay */
+#define R592_REG38_SHIFT		17
+
+/* Debug register, written (0xABCDEF00) when error happens - not used*/
+#define R592_REG_3C			0x3C
+
+struct r592_device {
+	struct pci_dev *pci_dev;
+	struct memstick_host	*host;		/* host backpointer */
+	struct memstick_request *req;		/* current request */
+
+	/* Registers, IRQ */
+	void __iomem *mmio;
+	int irq;
+	spinlock_t irq_lock;
+	spinlock_t io_thread_lock;
+	struct timer_list detect_timer;
+
+	struct task_struct *io_thread;
+	bool parallel_mode;
+
+	DECLARE_KFIFO(pio_fifo, u8, sizeof(u32));
+
+	/* DMA area */
+	int dma_capable;
+	int dma_error;
+	struct completion dma_done;
+	void *dummy_dma_page;
+	dma_addr_t dummy_dma_page_physical_address;
+
+};
+
+#define DRV_NAME "r592"
+
+
+#define message(format, ...) \
+	printk(KERN_INFO DRV_NAME ": " format "\n", ## __VA_ARGS__)
+
+#define __dbg(level, format, ...) \
+	do { \
+		if (debug >= level) \
+			printk(KERN_DEBUG DRV_NAME \
+				": " format "\n", ## __VA_ARGS__); \
+	} while (0)
+
+
+#define dbg(format, ...)		__dbg(1, format, ## __VA_ARGS__)
+#define dbg_verbose(format, ...)	__dbg(2, format, ## __VA_ARGS__)
+#define dbg_reg(format, ...)		__dbg(3, format, ## __VA_ARGS__)
+
+#endif