wbsd.c

The latest MontaVista Linux driver about SD/MMC code

/*
 *  linux/drivers/mmc/wbsd.c
 *
 *  Copyright (C) 2004 Pierre Ossman, All Rights Reserved.
 *
 * 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/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/blkdev.h>

#include <linux/mmc/host.h>
#include <linux/mmc/protocol.h>

#include <asm/io.h>
#include <asm/dma.h>

#include "wbsd.h"

#define DRIVER_NAME "wbsd"
#define DRIVER_VERSION "1.0"

#ifdef CONFIG_MMC_DEBUG
#define DBG(x...) \
	printk(KERN_DEBUG DRIVER_NAME ": " x)
#define DBGF(f, x...) \
	printk(KERN_DEBUG DRIVER_NAME " [%s()]: " f, __func__, ##x)
#else
#define DBG(x...)	do { } while (0)
#define DBGF(x...)	do { } while (0)
#endif

static unsigned int io = 0x248;
static unsigned int irq = 6;
static int dma = 2;

#ifdef CONFIG_MMC_DEBUG
void DBG_REG(int reg, u8 value)
{
	int i;
	
	printk(KERN_DEBUG "wbsd: Register %d: 0x%02X %3d '%c' ",
		reg, (int)value, (int)value, (value < 0x20)?'.':value);
	
	for (i = 7;i >= 0;i--)
	{
		if (value & (1 << i))
			printk("x");
		else
			printk(".");
	}
	
	printk("\n");
}
#else
#define DBG_REG(r, v) do {}  while (0)
#endif

/*
 * Basic functions
 */

static inline void wbsd_unlock_config(struct wbsd_host* host)
{
	outb(host->unlock_code, host->config);
	outb(host->unlock_code, host->config);
}

static inline void wbsd_lock_config(struct wbsd_host* host)
{
	outb(LOCK_CODE, host->config);
}

static inline void wbsd_write_config(struct wbsd_host* host, u8 reg, u8 value)
{
	outb(reg, host->config);
	outb(value, host->config + 1);
}

static inline u8 wbsd_read_config(struct wbsd_host* host, u8 reg)
{
	outb(reg, host->config);
	return inb(host->config + 1);
}

static inline void wbsd_write_index(struct wbsd_host* host, u8 index, u8 value)
{
	outb(index, host->base + WBSD_IDXR);
	outb(value, host->base + WBSD_DATAR);
}

static inline u8 wbsd_read_index(struct wbsd_host* host, u8 index)
{
	outb(index, host->base + WBSD_IDXR);
	return inb(host->base + WBSD_DATAR);
}

/*
 * Common routines
 */

static void wbsd_init_device(struct wbsd_host* host)
{
	u8 setup, ier;
	
	/*
	 * Reset chip (SD/MMC part) and fifo.
	 */
	setup = wbsd_read_index(host, WBSD_IDX_SETUP);
	setup |= WBSD_FIFO_RESET | WBSD_SOFT_RESET;
	wbsd_write_index(host, WBSD_IDX_SETUP, setup);
	
	/*
	 * Read back default clock.
	 */
	host->clk = wbsd_read_index(host, WBSD_IDX_CLK);

	/*
	 * Power down port.
	 */
	outb(WBSD_POWER_N, host->base + WBSD_CSR);
	
	/*
	 * Set maximum timeout.
	 */
	wbsd_write_index(host, WBSD_IDX_TAAC, 0x7F);
	
	/*
	 * Enable interesting interrupts.
	 */
	ier = 0;
	ier |= WBSD_EINT_CARD;
	ier |= WBSD_EINT_FIFO_THRE;
	ier |= WBSD_EINT_CCRC;
	ier |= WBSD_EINT_TIMEOUT;
	ier |= WBSD_EINT_CRC;
	ier |= WBSD_EINT_TC;

	outb(ier, host->base + WBSD_EIR);

	/*
	 * Clear interrupts.
	 */
	inb(host->base + WBSD_ISR);
}

static void wbsd_reset(struct wbsd_host* host)
{
	u8 setup;
	
	printk(KERN_ERR DRIVER_NAME ": Resetting chip\n");
	
	/*
	 * Soft reset of chip (SD/MMC part).
	 */
	setup = wbsd_read_index(host, WBSD_IDX_SETUP);
	setup |= WBSD_SOFT_RESET;
	wbsd_write_index(host, WBSD_IDX_SETUP, setup);
}

static void wbsd_request_end(struct wbsd_host* host, struct mmc_request* mrq)
{
	unsigned long dmaflags;
	
	DBGF("Ending request, cmd (%x)\n", mrq->cmd->opcode);
	
	if (host->dma >= 0)
	{
		/*
		 * Release ISA DMA controller.
		 */
		dmaflags = claim_dma_lock();
		disable_dma(host->dma);
		clear_dma_ff(host->dma);
		release_dma_lock(dmaflags);

		/*
		 * Disable DMA on host.
		 */
		wbsd_write_index(host, WBSD_IDX_DMA, 0);
	}
	
	host->mrq = NULL;

	/*
	 * MMC layer might call back into the driver so first unlock.
	 */
	spin_unlock(&host->lock);
	mmc_request_done(host->mmc, mrq);
	spin_lock(&host->lock);
}

/*
 * Scatter/gather functions
 */

static inline void wbsd_init_sg(struct wbsd_host* host, struct mmc_data* data)
{
	struct request* req = data->req;
	
	/*
	 * Get info. about SG list from data structure.
	 */
	host->cur_sg = data->sg;
	host->num_sg = data->sg_len;

	host->offset = 0;
	host->remain = host->cur_sg->length;
}

static inline int wbsd_next_sg(struct wbsd_host* host)
{
	/*
	 * Skip to next SG entry.
	 */
	host->cur_sg++;
	host->num_sg--;

	/*
	 * Any entries left?
	 */
	if (host->num_sg > 0)
	  {
	    host->offset = 0;
	    host->remain = host->cur_sg->length;
	  }
	
	return host->num_sg;
}

static inline char* wbsd_kmap_sg(struct wbsd_host* host)
{
	return kmap_atomic(host->cur_sg->page, KM_BIO_SRC_IRQ) +
		host->cur_sg->offset;
}

static inline void wbsd_kunmap_sg(struct wbsd_host* host)
{
	kunmap_atomic(host->cur_sg->page, KM_BIO_SRC_IRQ);
}

static inline void wbsd_sg_to_dma(struct wbsd_host* host, struct mmc_data* data)
{
	unsigned int len, i, size;
	struct scatterlist* sg;
	char* dmabuf = host->dma_buffer;
	char* sgbuf;
	
	size = host->size;
	
	sg = data->sg;
	len = data->sg_len;
	
	/*
	 * Just loop through all entries. Size might not
	 * be the entire list though so make sure that
	 * we do not transfer too much.
	 */
	for (i = 0;i < len;i++)
	{
		sgbuf = kmap_atomic(sg[i].page, KM_BIO_SRC_IRQ) + sg[i].offset;
		if (size < sg[i].length)
			memcpy(dmabuf, sgbuf, size);
		else
			memcpy(dmabuf, sgbuf, sg[i].length);
		kunmap_atomic(sg[i].page, KM_BIO_SRC_IRQ);
		dmabuf += sg[i].length;
		
		if (size < sg[i].length)
			size = 0;
		else
			size -= sg[i].length;
	
		if (size == 0)
			break;
	}
	
	/*
	 * Check that we didn't get a request to transfer
	 * more data than can fit into the SG list.
	 */
	
	BUG_ON(size != 0);
	
	host->size -= size;
}

static inline void wbsd_dma_to_sg(struct wbsd_host* host, struct mmc_data* data)
{
	unsigned int len, i, size;
	struct scatterlist* sg;
	char* dmabuf = host->dma_buffer;
	char* sgbuf;
	
	size = host->size;
	
	sg = data->sg;
	len = data->sg_len;
	
	/*
	 * Just loop through all entries. Size might not
	 * be the entire list though so make sure that
	 * we do not transfer too much.
	 */
	for (i = 0;i < len;i++)
	{
		sgbuf = kmap_atomic(sg[i].page, KM_BIO_SRC_IRQ) + sg[i].offset;
		if (size < sg[i].length)
			memcpy(sgbuf, dmabuf, size);
		else
			memcpy(sgbuf, dmabuf, sg[i].length);
		kunmap_atomic(sg[i].page, KM_BIO_SRC_IRQ);
		dmabuf += sg[i].length;
		
		if (size < sg[i].length)
			size = 0;
		else
			size -= sg[i].length;
		
		if (size == 0)
			break;
	}
	
	/*
	 * Check that we didn't get a request to transfer
	 * more data than can fit into the SG list.
	 */
	
	BUG_ON(size != 0);
	
	host->size -= size;
}

/*
 * Command handling
 */
 
static inline void wbsd_get_short_reply(struct wbsd_host* host,
	struct mmc_command* cmd)
{
	/*
	 * Correct response type?
	 */
	if (wbsd_read_index(host, WBSD_IDX_RSPLEN) != WBSD_RSP_SHORT)
	{
		cmd->error = MMC_ERR_INVALID;
		return;
	}
	
	cmd->resp[0] =
		wbsd_read_index(host, WBSD_IDX_RESP12) << 24;
	cmd->resp[0] |=
		wbsd_read_index(host, WBSD_IDX_RESP13) << 16;
	cmd->resp[0] |=
		wbsd_read_index(host, WBSD_IDX_RESP14) << 8;
	cmd->resp[0] |=
		wbsd_read_index(host, WBSD_IDX_RESP15) << 0;
	cmd->resp[1] =
		wbsd_read_index(host, WBSD_IDX_RESP16) << 24;
}

static inline void wbsd_get_long_reply(struct wbsd_host* host,
	struct mmc_command* cmd)
{
	int i;
	
	/*
	 * Correct response type?
	 */
	if (wbsd_read_index(host, WBSD_IDX_RSPLEN) != WBSD_RSP_LONG)
	{
		cmd->error = MMC_ERR_INVALID;
		return;
	}
	
	for (i = 0;i < 4;i++)
	{
		cmd->resp[i] =
			wbsd_read_index(host, WBSD_IDX_RESP1 + i * 4) << 24;
		cmd->resp[i] |=
			wbsd_read_index(host, WBSD_IDX_RESP2 + i * 4) << 16;
		cmd->resp[i] |=
			wbsd_read_index(host, WBSD_IDX_RESP3 + i * 4) << 8;
		cmd->resp[i] |=
			wbsd_read_index(host, WBSD_IDX_RESP4 + i * 4) << 0;
	}
}

static irqreturn_t wbsd_irq(int irq, void *dev_id, struct pt_regs *regs);

static void wbsd_send_command(struct wbsd_host* host, struct mmc_command* cmd)
{
	int i;
	u8 status, eir, isr;
	
	DBGF("Sending cmd (%x)\n", cmd->opcode);

	/*
	 * Disable interrupts as the interrupt routine
	 * will destroy the contents of ISR.
	 */
	eir = inb(host->base + WBSD_EIR);
	outb(0, host->base + WBSD_EIR);
	
	/*
	 * Send the command (CRC calculated by host).
	 */
	outb(cmd->opcode, host->base + WBSD_CMDR);
	for (i = 3;i >= 0;i--)
		outb((cmd->arg >> (i * 8)) & 0xff, host->base + WBSD_CMDR);
	
	cmd->error = MMC_ERR_NONE;
	
	/*
	 * Wait for the request to complete.
	 */
	do {
		status = wbsd_read_index(host, WBSD_IDX_STATUS);
	} while (status & WBSD_CARDTRAFFIC);

	/*
	 * Do we expect a reply?
	 */
	if ((cmd->flags & MMC_RSP_MASK) != MMC_RSP_NONE)
	{
		/*
		 * Read back status.
		 */
		isr = inb(host->base + WBSD_ISR);
		
		/* Card removed? */
		if (isr & WBSD_INT_CARD)
			cmd->error = MMC_ERR_TIMEOUT;
		/* Timeout? */
		else if (isr & WBSD_INT_TIMEOUT)
			cmd->error = MMC_ERR_TIMEOUT;
		/* CRC? */
		else if ((cmd->flags & MMC_RSP_CRC) && (isr & WBSD_INT_CRC))
			cmd->error = MMC_ERR_BADCRC;
		/* All ok */
		else
		{
			if ((cmd->flags & MMC_RSP_MASK) == MMC_RSP_SHORT)
				wbsd_get_short_reply(host, cmd);
			else
				wbsd_get_long_reply(host, cmd);
		}
	}

	/*
	 * Restore interrupt mask to previous value.
	 */
	outb(eir, host->base + WBSD_EIR);
	
	/*
	 * Call the interrupt routine to jump start
	 * interrupts.
	 */
	wbsd_irq(0, host, NULL);

	DBGF("Sent cmd (%x), res %d\n", cmd->opcode, cmd->error);
}

/*
 * Data functions
 */

static void wbsd_empty_fifo(struct wbsd_host* host)
{
	struct mmc_data* data = host->mrq->cmd->data;
	char* buffer;
	
	/*
	 * Handle excessive data.
	 */
	if (data->bytes_xfered == host->size)
		return;
	
	buffer = wbsd_kmap_sg(host) + host->offset;

	/*
	 * Drain the fifo. This has a tendency to loop longer
	 * than the FIFO length (usually one block).
	 */
	while (!(inb(host->base + WBSD_FSR) & WBSD_FIFO_EMPTY))
	{
		*buffer = inb(host->base + WBSD_DFR);
		buffer++;
		host->offset++;
		host->remain--;

		data->bytes_xfered++;
		
		/*
		 * Transfer done?
		 */
		if (data->bytes_xfered == host->size)
		{
			wbsd_kunmap_sg(host);				
			return;
		}
		
		/*
		 * End of scatter list entry?
		 */
		if (host->remain == 0)
		{
			wbsd_kunmap_sg(host);
			
			/*
			 * Get next entry. Check if last.
			 */
			if (!wbsd_next_sg(host))
			{
				/*
				 * We should never reach this point.
				 * It means that we're trying to
				 * transfer more blocks than can fit
				 * into the scatter list.
				 */
				BUG_ON(1);
				
				host->size = data->bytes_xfered;
				
				return;
			}
			
			buffer = wbsd_kmap_sg(host);
		}
	}
	
	wbsd_kunmap_sg(host);
}

static void wbsd_fill_fifo(struct wbsd_host* host)
{
	struct mmc_data* data = host->mrq->cmd->data;
	char* buffer;
	
	/*
	 * Check that we aren't being called after the
	 * entire buffer has been transfered.
	 */
	if (data->bytes_xfered == host->size)
		return;

	buffer = wbsd_kmap_sg(host) + host->offset;

	/*
	 * Fill the fifo. This has a tendency to loop longer
	 * than the FIFO length (usually one block).
	 */
	while (!(inb(host->base + WBSD_FSR) & WBSD_FIFO_FULL))
	{
		outb(*buffer, host->base + WBSD_DFR);
		buffer++;
		host->offset++;
		host->remain--;
		
		data->bytes_xfered++;
		
		/*
		 * Transfer done?
		 */
		if (data->bytes_xfered == host->size)
		{
			wbsd_kunmap_sg(host);
			return;
		}

		/*
		 * End of scatter list entry?
		 */
		if (host->remain == 0)
		{
			wbsd_kunmap_sg(host);
			
			/*
			 * Get next entry. Check if last.
			 */
			if (!wbsd_next_sg(host))
			{
				/*
				 * We should never reach this point.
				 * It means that we're trying to
				 * transfer more blocks than can fit
				 * into the scatter list.
				 */
				BUG_ON(1);
				
				host->size = data->bytes_xfered;
				
				return;
			}
			
			buffer = wbsd_kmap_sg(host);
		}
	}
	
	wbsd_kunmap_sg(host);
}

static void wbsd_prepare_data(struct wbsd_host* host, struct mmc_data* data)
{
	u16 blksize;
	u8 setup;
	unsigned long dmaflags;

	DBGF("blksz %04x blks %04x flags %08x\n",
		1 << data->blksz_bits, data->blocks, data->flags);
	DBGF("tsac %d ms nsac %d clk\n",
		data->timeout_ns / 1000000, data->timeout_clks);
	
	/*
	 * Calculate size.
	 */
	host->size = data->blocks << data->blksz_bits;

	/*
	 * Check timeout values for overflow.
	 * (Yes, some cards cause this value to overflow).
	 */
	if (data->timeout_ns > 127000000)
		wbsd_write_index(host, WBSD_IDX_TAAC, 127);
	else
		wbsd_write_index(host, WBSD_IDX_TAAC, data->timeout_ns/1000000);
	
	if (data->timeout_clks > 255)
		wbsd_write_index(host, WBSD_IDX_NSAC, 255);
	else
		wbsd_write_index(host, WBSD_IDX_NSAC, data->timeout_clks);
	
	/*
	 * Inform the chip of how large blocks will be
	 * sent. It needs this to determine when to
	 * calculate CRC.
	 *
	 * Space for CRC must be included in the size.
	 */
	blksize = (1 << data->blksz_bits) + 2;
	
	wbsd_write_index(host, WBSD_IDX_PBSMSB, (blksize >> 4) & 0xF0);
	wbsd_write_index(host, WBSD_IDX_PBSLSB, blksize & 0xFF);

	/*
	 * Clear the FIFO. This is needed even for DMA
	 * transfers since the chip still uses the FIFO
	 * internally.
	 */
	setup = wbsd_read_index(host, WBSD_IDX_SETUP);
	setup |= WBSD_FIFO_RESET;
	wbsd_write_index(host, WBSD_IDX_SETUP, setup);
	
	/*
	 * DMA transfer?
	 */
	if (host->dma >= 0)
	{	
		/*
		 * The buffer for DMA is only 64 kB.
		 */
		BUG_ON(host->size > 0x10000);
		if (host->size > 0x10000)
		{
			data->error = MMC_ERR_INVALID;
			return;
		}
		
		/*
		 * Transfer data from the SG list to
		 * the DMA buffer.
		 */
		if (data->flags & MMC_DATA_WRITE)
			wbsd_sg_to_dma(host, data);
		
		/*
		 * Initialise the ISA DMA controller.
		 */	
		dmaflags = claim_dma_lock();
		disable_dma(host->dma);
		clear_dma_ff(host->dma);
		if (data->flags & MMC_DATA_READ)
			set_dma_mode(host->dma, DMA_MODE_READ);
		else
			set_dma_mode(host->dma, DMA_MODE_WRITE);
		set_dma_addr(host->dma, host->dma_addr);
		set_dma_count(host->dma, host->size);

		enable_dma(host->dma);
		release_dma_lock(dmaflags);

		/*
		 * Enable DMA on the host.
		 */
		wbsd_write_index(host, WBSD_IDX_DMA,
			WBSD_DMA_SINGLE | WBSD_DMA_ENABLE);
	}
	else
	{
		/*
		 * This flag is used to keep printk
		 * output to a minimum.
		 */
		host->firsterr = 1;
		
		/*
		 * Initialise the SG list.
		 */
		wbsd_init_sg(host, data);
	
		/*
		 * Turn off DMA.
		 */
		wbsd_write_index(host, WBSD_IDX_DMA, 0);
	
		/*
		 * Set up FIFO threshold levels (and fill
		 * buffer if doing a write).
		 */
		if (data->flags & MMC_DATA_READ)
		{
			wbsd_write_index(host, WBSD_IDX_FIFOEN,
				WBSD_FIFOEN_FULL | 8);
		}
		else
		{
			wbsd_write_index(host, WBSD_IDX_FIFOEN,
				WBSD_FIFOEN_EMPTY | 8);
			wbsd_fill_fifo(host);
		}
	}	
		
	data->error = MMC_ERR_NONE;
}

static void wbsd_finish_data(struct wbsd_host* host, struct mmc_data* data)
{
	unsigned long dmaflags;
	int count;
	
	WARN_ON(host->mrq == NULL);

	/*
	 * Send a stop command if needed.
	 */
	if (data->stop)
		wbsd_send_command(host, data->stop);
	
	/*
	 * DMA transfer?
	 */
	if (host->dma >= 0)
	{
		/*
		 * Disable DMA on the host.
		 */
		wbsd_write_index(host, WBSD_IDX_DMA, 0);
		
		/*
		 * Turn of ISA DMA controller.
		 */
		dmaflags = claim_dma_lock();
		disable_dma(host->dma);
		clear_dma_ff(host->dma);
		count = get_dma_residue(host->dma);
		release_dma_lock(dmaflags);
		
		/*
		 * Any leftover data?
		 */
		if (count)
		{
			printk(KERN_ERR DRIVER_NAME ": Incomplete DMA "
				"transfer. %d bytes left.\n", count);
			
			data->error = MMC_ERR_FAILED;
		}
		else
		{
			/*
			 * Transfer data from DMA buffer to
			 * SG list.
			 */
			if (data->flags & MMC_DATA_READ)
				wbsd_dma_to_sg(host, data);
			
			data->bytes_xfered = host->size;
		}
	}