sdhci.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

/*
 *  linux/drivers/mmc/sdhci.c - Secure Digital Host Controller Interface driver
 *
 *  Copyright (C) 2005-2006 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 as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>

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

#include <asm/scatterlist.h>

#include "sdhci.h"

#define DRIVER_NAME "sdhci"
#define DRIVER_VERSION "0.12"

#define BUGMAIL "<[e-mail]>"

#define DBG(f, x...) \
	pr_debug(DRIVER_NAME " [%s()]: " f, __func__,## x)

static unsigned int debug_nodma = 0;
static unsigned int debug_forcedma = 0;
static unsigned int debug_quirks = 0;

#define SDHCI_QUIRK_CLOCK_BEFORE_RESET			(1<<0)
#define SDHCI_QUIRK_FORCE_DMA				(1<<1)
/* Controller doesn't like some resets when there is no card inserted. */
#define SDHCI_QUIRK_NO_CARD_NO_RESET			(1<<2)

static const struct pci_device_id pci_ids[] __devinitdata = {
	{
		.vendor		= PCI_VENDOR_ID_RICOH,
		.device		= PCI_DEVICE_ID_RICOH_R5C822,
		.subvendor	= PCI_VENDOR_ID_IBM,
		.subdevice	= PCI_ANY_ID,
		.driver_data	= SDHCI_QUIRK_CLOCK_BEFORE_RESET |
				  SDHCI_QUIRK_FORCE_DMA,
	},

	{
		.vendor		= PCI_VENDOR_ID_RICOH,
		.device		= PCI_DEVICE_ID_RICOH_R5C822,
		.subvendor	= PCI_ANY_ID,
		.subdevice	= PCI_ANY_ID,
		.driver_data	= SDHCI_QUIRK_FORCE_DMA |
				  SDHCI_QUIRK_NO_CARD_NO_RESET,
	},

	{
		.vendor		= PCI_VENDOR_ID_TI,
		.device		= PCI_DEVICE_ID_TI_XX21_XX11_SD,
		.subvendor	= PCI_ANY_ID,
		.subdevice	= PCI_ANY_ID,
		.driver_data	= SDHCI_QUIRK_FORCE_DMA,
	},

	{	/* Generic SD host controller */
		PCI_DEVICE_CLASS((PCI_CLASS_SYSTEM_SDHCI << 8), 0xFFFF00)
	},

	{ /* end: all zeroes */ },
};

MODULE_DEVICE_TABLE(pci, pci_ids);

static void sdhci_prepare_data(struct sdhci_host *, struct mmc_data *);
static void sdhci_finish_data(struct sdhci_host *);

static void sdhci_send_command(struct sdhci_host *, struct mmc_command *);
static void sdhci_finish_command(struct sdhci_host *);

static void sdhci_dumpregs(struct sdhci_host *host)
{
	printk(KERN_DEBUG DRIVER_NAME ": ============== REGISTER DUMP ==============\n");

	printk(KERN_DEBUG DRIVER_NAME ": Sys addr: 0x%08x | Version:  0x%08x\n",
		readl(host->ioaddr + SDHCI_DMA_ADDRESS),
		readw(host->ioaddr + SDHCI_HOST_VERSION));
	printk(KERN_DEBUG DRIVER_NAME ": Blk size: 0x%08x | Blk cnt:  0x%08x\n",
		readw(host->ioaddr + SDHCI_BLOCK_SIZE),
		readw(host->ioaddr + SDHCI_BLOCK_COUNT));
	printk(KERN_DEBUG DRIVER_NAME ": Argument: 0x%08x | Trn mode: 0x%08x\n",
		readl(host->ioaddr + SDHCI_ARGUMENT),
		readw(host->ioaddr + SDHCI_TRANSFER_MODE));
	printk(KERN_DEBUG DRIVER_NAME ": Present:  0x%08x | Host ctl: 0x%08x\n",
		readl(host->ioaddr + SDHCI_PRESENT_STATE),
		readb(host->ioaddr + SDHCI_HOST_CONTROL));
	printk(KERN_DEBUG DRIVER_NAME ": Power:    0x%08x | Blk gap:  0x%08x\n",
		readb(host->ioaddr + SDHCI_POWER_CONTROL),
		readb(host->ioaddr + SDHCI_BLOCK_GAP_CONTROL));
	printk(KERN_DEBUG DRIVER_NAME ": Wake-up:  0x%08x | Clock:    0x%08x\n",
		readb(host->ioaddr + SDHCI_WALK_UP_CONTROL),
		readw(host->ioaddr + SDHCI_CLOCK_CONTROL));
	printk(KERN_DEBUG DRIVER_NAME ": Timeout:  0x%08x | Int stat: 0x%08x\n",
		readb(host->ioaddr + SDHCI_TIMEOUT_CONTROL),
		readl(host->ioaddr + SDHCI_INT_STATUS));
	printk(KERN_DEBUG DRIVER_NAME ": Int enab: 0x%08x | Sig enab: 0x%08x\n",
		readl(host->ioaddr + SDHCI_INT_ENABLE),
		readl(host->ioaddr + SDHCI_SIGNAL_ENABLE));
	printk(KERN_DEBUG DRIVER_NAME ": AC12 err: 0x%08x | Slot int: 0x%08x\n",
		readw(host->ioaddr + SDHCI_ACMD12_ERR),
		readw(host->ioaddr + SDHCI_SLOT_INT_STATUS));
	printk(KERN_DEBUG DRIVER_NAME ": Caps:     0x%08x | Max curr: 0x%08x\n",
		readl(host->ioaddr + SDHCI_CAPABILITIES),
		readl(host->ioaddr + SDHCI_MAX_CURRENT));

	printk(KERN_DEBUG DRIVER_NAME ": ===========================================\n");
}

/*****************************************************************************\
 *                                                                           *
 * Low level functions                                                       *
 *                                                                           *
\*****************************************************************************/

static void sdhci_reset(struct sdhci_host *host, u8 mask)
{
	unsigned long timeout;

	if (host->chip->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
		if (!(readl(host->ioaddr + SDHCI_PRESENT_STATE) &
			SDHCI_CARD_PRESENT))
			return;
	}

	writeb(mask, host->ioaddr + SDHCI_SOFTWARE_RESET);

	if (mask & SDHCI_RESET_ALL)
		host->clock = 0;

	/* Wait max 100 ms */
	timeout = 100;

	/* hw clears the bit when it's done */
	while (readb(host->ioaddr + SDHCI_SOFTWARE_RESET) & mask) {
		if (timeout == 0) {
			printk(KERN_ERR "%s: Reset 0x%x never completed. "
				"Please report this to " BUGMAIL ".\n",
				mmc_hostname(host->mmc), (int)mask);
			sdhci_dumpregs(host);
			return;
		}
		timeout--;
		mdelay(1);
	}
}

static void sdhci_init(struct sdhci_host *host)
{
	u32 intmask;

	sdhci_reset(host, SDHCI_RESET_ALL);

	intmask = SDHCI_INT_BUS_POWER | SDHCI_INT_DATA_END_BIT |
		SDHCI_INT_DATA_CRC | SDHCI_INT_DATA_TIMEOUT | SDHCI_INT_INDEX |
		SDHCI_INT_END_BIT | SDHCI_INT_CRC | SDHCI_INT_TIMEOUT |
		SDHCI_INT_CARD_REMOVE | SDHCI_INT_CARD_INSERT |
		SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL |
		SDHCI_INT_DMA_END | SDHCI_INT_DATA_END | SDHCI_INT_RESPONSE;

	writel(intmask, host->ioaddr + SDHCI_INT_ENABLE);
	writel(intmask, host->ioaddr + SDHCI_SIGNAL_ENABLE);
}

static void sdhci_activate_led(struct sdhci_host *host)
{
	u8 ctrl;

	ctrl = readb(host->ioaddr + SDHCI_HOST_CONTROL);
	ctrl |= SDHCI_CTRL_LED;
	writeb(ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
}

static void sdhci_deactivate_led(struct sdhci_host *host)
{
	u8 ctrl;

	ctrl = readb(host->ioaddr + SDHCI_HOST_CONTROL);
	ctrl &= ~SDHCI_CTRL_LED;
	writeb(ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
}

/*****************************************************************************\
 *                                                                           *
 * Core functions                                                            *
 *                                                                           *
\*****************************************************************************/

static inline char* sdhci_kmap_sg(struct sdhci_host* host)
{
	host->mapped_sg = kmap_atomic(host->cur_sg->page, KM_BIO_SRC_IRQ);
	return host->mapped_sg + host->cur_sg->offset;
}

static inline void sdhci_kunmap_sg(struct sdhci_host* host)
{
	kunmap_atomic(host->mapped_sg, KM_BIO_SRC_IRQ);
}

static inline int sdhci_next_sg(struct sdhci_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 void sdhci_read_block_pio(struct sdhci_host *host)
{
	int blksize, chunk_remain;
	u32 data;
	char *buffer;
	int size;

	DBG("PIO reading\n");

	blksize = host->data->blksz;
	chunk_remain = 0;
	data = 0;

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

	while (blksize) {
		if (chunk_remain == 0) {
			data = readl(host->ioaddr + SDHCI_BUFFER);
			chunk_remain = min(blksize, 4);
		}

		size = min(host->size, host->remain);
		size = min(size, chunk_remain);

		chunk_remain -= size;
		blksize -= size;
		host->offset += size;
		host->remain -= size;
		host->size -= size;
		while (size) {
			*buffer = data & 0xFF;
			buffer++;
			data >>= 8;
			size--;
		}

		if (host->remain == 0) {
			sdhci_kunmap_sg(host);
			if (sdhci_next_sg(host) == 0) {
				BUG_ON(blksize != 0);
				return;
			}
			buffer = sdhci_kmap_sg(host);
		}
	}

	sdhci_kunmap_sg(host);
}

static void sdhci_write_block_pio(struct sdhci_host *host)
{
	int blksize, chunk_remain;
	u32 data;
	char *buffer;
	int bytes, size;

	DBG("PIO writing\n");

	blksize = host->data->blksz;
	chunk_remain = 4;
	data = 0;

	bytes = 0;
	buffer = sdhci_kmap_sg(host) + host->offset;

	while (blksize) {
		size = min(host->size, host->remain);
		size = min(size, chunk_remain);

		chunk_remain -= size;
		blksize -= size;
		host->offset += size;
		host->remain -= size;
		host->size -= size;
		while (size) {
			data >>= 8;
			data |= (u32)*buffer << 24;
			buffer++;
			size--;
		}

		if (chunk_remain == 0) {
			writel(data, host->ioaddr + SDHCI_BUFFER);
			chunk_remain = min(blksize, 4);
		}

		if (host->remain == 0) {
			sdhci_kunmap_sg(host);
			if (sdhci_next_sg(host) == 0) {
				BUG_ON(blksize != 0);
				return;
			}
			buffer = sdhci_kmap_sg(host);
		}
	}

	sdhci_kunmap_sg(host);
}

static void sdhci_transfer_pio(struct sdhci_host *host)
{
	u32 mask;

	BUG_ON(!host->data);

	if (host->size == 0)
		return;

	if (host->data->flags & MMC_DATA_READ)
		mask = SDHCI_DATA_AVAILABLE;
	else
		mask = SDHCI_SPACE_AVAILABLE;

	while (readl(host->ioaddr + SDHCI_PRESENT_STATE) & mask) {
		if (host->data->flags & MMC_DATA_READ)
			sdhci_read_block_pio(host);
		else
			sdhci_write_block_pio(host);

		if (host->size == 0)
			break;

		BUG_ON(host->num_sg == 0);
	}

	DBG("PIO transfer complete.\n");
}

static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
{
	u8 count;
	unsigned target_timeout, current_timeout;

	WARN_ON(host->data);

	if (data == NULL)
		return;

	DBG("blksz %04x blks %04x flags %08x\n",
		data->blksz, data->blocks, data->flags);
	DBG("tsac %d ms nsac %d clk\n",
		data->timeout_ns / 1000000, data->timeout_clks);

	/* Sanity checks */
	BUG_ON(data->blksz * data->blocks > 524288);
	BUG_ON(data->blksz > host->max_block);
	BUG_ON(data->blocks > 65535);

	/* timeout in us */
	target_timeout = data->timeout_ns / 1000 +
		data->timeout_clks / host->clock;

	/*
	 * Figure out needed cycles.
	 * We do this in steps in order to fit inside a 32 bit int.
	 * The first step is the minimum timeout, which will have a
	 * minimum resolution of 6 bits:
	 * (1) 2^13*1000 > 2^22,
	 * (2) host->timeout_clk < 2^16
	 *     =>
	 *     (1) / (2) > 2^6
	 */
	count = 0;
	current_timeout = (1 << 13) * 1000 / host->timeout_clk;
	while (current_timeout < target_timeout) {
		count++;
		current_timeout <<= 1;
		if (count >= 0xF)
			break;
	}

	if (count >= 0xF) {
		printk(KERN_WARNING "%s: Too large timeout requested!\n",
			mmc_hostname(host->mmc));
		count = 0xE;
	}

	writeb(count, host->ioaddr + SDHCI_TIMEOUT_CONTROL);

	if (host->flags & SDHCI_USE_DMA) {
		int count;

		count = pci_map_sg(host->chip->pdev, data->sg, data->sg_len,
			(data->flags & MMC_DATA_READ)?PCI_DMA_FROMDEVICE:PCI_DMA_TODEVICE);
		BUG_ON(count != 1);

		writel(sg_dma_address(data->sg), host->ioaddr + SDHCI_DMA_ADDRESS);
	} else {
		host->size = data->blksz * data->blocks;

		host->cur_sg = data->sg;
		host->num_sg = data->sg_len;

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

	/* We do not handle DMA boundaries, so set it to max (512 KiB) */
	writew(SDHCI_MAKE_BLKSZ(7, data->blksz),
		host->ioaddr + SDHCI_BLOCK_SIZE);
	writew(data->blocks, host->ioaddr + SDHCI_BLOCK_COUNT);
}

static void sdhci_set_transfer_mode(struct sdhci_host *host,
	struct mmc_data *data)
{
	u16 mode;

	WARN_ON(host->data);

	if (data == NULL)
		return;

	mode = SDHCI_TRNS_BLK_CNT_EN;
	if (data->blocks > 1)
		mode |= SDHCI_TRNS_MULTI;
	if (data->flags & MMC_DATA_READ)
		mode |= SDHCI_TRNS_READ;
	if (host->flags & SDHCI_USE_DMA)
		mode |= SDHCI_TRNS_DMA;

	writew(mode, host->ioaddr + SDHCI_TRANSFER_MODE);
}

static void sdhci_finish_data(struct sdhci_host *host)
{
	struct mmc_data *data;
	u16 blocks;

	BUG_ON(!host->data);

	data = host->data;
	host->data = NULL;

	if (host->flags & SDHCI_USE_DMA) {
		pci_unmap_sg(host->chip->pdev, data->sg, data->sg_len,
			(data->flags & MMC_DATA_READ)?PCI_DMA_FROMDEVICE:PCI_DMA_TODEVICE);
	}

	/*
	 * Controller doesn't count down when in single block mode.
	 */
	if ((data->blocks == 1) && (data->error == MMC_ERR_NONE))
		blocks = 0;
	else
		blocks = readw(host->ioaddr + SDHCI_BLOCK_COUNT);
	data->bytes_xfered = data->blksz * (data->blocks - blocks);

	if ((data->error == MMC_ERR_NONE) && blocks) {
		printk(KERN_ERR "%s: Controller signalled completion even "
			"though there were blocks left. Please report this "
			"to " BUGMAIL ".\n", mmc_hostname(host->mmc));
		data->error = MMC_ERR_FAILED;
	} else if (host->size != 0) {
		printk(KERN_ERR "%s: %d bytes were left untransferred. "
			"Please report this to " BUGMAIL ".\n",
			mmc_hostname(host->mmc), host->size);
		data->error = MMC_ERR_FAILED;
	}

	DBG("Ending data transfer (%d bytes)\n", data->bytes_xfered);

	if (data->stop) {
		/*
		 * The controller needs a reset of internal state machines
		 * upon error conditions.
		 */
		if (data->error != MMC_ERR_NONE) {
			sdhci_reset(host, SDHCI_RESET_CMD);
			sdhci_reset(host, SDHCI_RESET_DATA);
		}

		sdhci_send_command(host, data->stop);
	} else
		tasklet_schedule(&host->finish_tasklet);
}

static void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
{
	int flags;
	u32 mask;
	unsigned long timeout;

	WARN_ON(host->cmd);

	DBG("Sending cmd (%x)\n", cmd->opcode);