mmc.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

			card->cid.prod_name[1]	= UNSTUFF_BITS(resp, 88, 8);
			card->cid.prod_name[2]	= UNSTUFF_BITS(resp, 80, 8);
			card->cid.prod_name[3]	= UNSTUFF_BITS(resp, 72, 8);
			card->cid.prod_name[4]	= UNSTUFF_BITS(resp, 64, 8);
			card->cid.prod_name[5]	= UNSTUFF_BITS(resp, 56, 8);
			card->cid.prod_name[6]	= UNSTUFF_BITS(resp, 48, 8);
			card->cid.hwrev		= UNSTUFF_BITS(resp, 44, 4);
			card->cid.fwrev		= UNSTUFF_BITS(resp, 40, 4);
			card->cid.serial	= UNSTUFF_BITS(resp, 16, 24);
			card->cid.month		= UNSTUFF_BITS(resp, 12, 4);
			card->cid.year		= UNSTUFF_BITS(resp, 8, 4) + 1997;
			break;

		case 2: /* MMC v2.0 - v2.2 */
		case 3: /* MMC v3.1 - v3.3 */
		case 4: /* MMC v4 */
			card->cid.manfid	= UNSTUFF_BITS(resp, 120, 8);
			card->cid.oemid		= UNSTUFF_BITS(resp, 104, 16);
			card->cid.prod_name[0]	= UNSTUFF_BITS(resp, 96, 8);
			card->cid.prod_name[1]	= UNSTUFF_BITS(resp, 88, 8);
			card->cid.prod_name[2]	= UNSTUFF_BITS(resp, 80, 8);
			card->cid.prod_name[3]	= UNSTUFF_BITS(resp, 72, 8);
			card->cid.prod_name[4]	= UNSTUFF_BITS(resp, 64, 8);
			card->cid.prod_name[5]	= UNSTUFF_BITS(resp, 56, 8);
			card->cid.serial	= UNSTUFF_BITS(resp, 16, 32);
			card->cid.month		= UNSTUFF_BITS(resp, 12, 4);
			card->cid.year		= UNSTUFF_BITS(resp, 8, 4) + 1997;
			break;

		default:
			printk("%s: card has unknown MMCA version %d\n",
				mmc_hostname(card->host), card->csd.mmca_vsn);
			mmc_card_set_bad(card);
			break;
		}
	}
}

/*
 * Given a 128-bit response, decode to our card CSD structure.
 */
static void mmc_decode_csd(struct mmc_card *card)
{
	struct mmc_csd *csd = &card->csd;
	unsigned int e, m, csd_struct;
	u32 *resp = card->raw_csd;

	if (mmc_card_sd(card)) {
		csd_struct = UNSTUFF_BITS(resp, 126, 2);
		if (csd_struct != 0) {
			printk("%s: unrecognised CSD structure version %d\n",
				mmc_hostname(card->host), csd_struct);
			mmc_card_set_bad(card);
			return;
		}

		m = UNSTUFF_BITS(resp, 115, 4);
		e = UNSTUFF_BITS(resp, 112, 3);
		csd->tacc_ns	 = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
		csd->tacc_clks	 = UNSTUFF_BITS(resp, 104, 8) * 100;

		m = UNSTUFF_BITS(resp, 99, 4);
		e = UNSTUFF_BITS(resp, 96, 3);
		csd->max_dtr	  = tran_exp[e] * tran_mant[m];
		csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);

		e = UNSTUFF_BITS(resp, 47, 3);
		m = UNSTUFF_BITS(resp, 62, 12);
		csd->capacity	  = (1 + m) << (e + 2);

		csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
		csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
		csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
		csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
		csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
		csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
		csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
	} else {
		/*
		 * We only understand CSD structure v1.1 and v1.2.
		 * v1.2 has extra information in bits 15, 11 and 10.
		 */
		csd_struct = UNSTUFF_BITS(resp, 126, 2);
		if (csd_struct != 1 && csd_struct != 2) {
			printk("%s: unrecognised CSD structure version %d\n",
				mmc_hostname(card->host), csd_struct);
			mmc_card_set_bad(card);
			return;
		}

		csd->mmca_vsn	 = UNSTUFF_BITS(resp, 122, 4);
		m = UNSTUFF_BITS(resp, 115, 4);
		e = UNSTUFF_BITS(resp, 112, 3);
		csd->tacc_ns	 = (tacc_exp[e] * tacc_mant[m] + 9) / 10;
		csd->tacc_clks	 = UNSTUFF_BITS(resp, 104, 8) * 100;

		m = UNSTUFF_BITS(resp, 99, 4);
		e = UNSTUFF_BITS(resp, 96, 3);
		csd->max_dtr	  = tran_exp[e] * tran_mant[m];
		csd->cmdclass	  = UNSTUFF_BITS(resp, 84, 12);

		e = UNSTUFF_BITS(resp, 47, 3);
		m = UNSTUFF_BITS(resp, 62, 12);
		csd->capacity	  = (1 + m) << (e + 2);

		csd->read_blkbits = UNSTUFF_BITS(resp, 80, 4);
		csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
		csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
		csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
		csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
		csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
		csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
	}
}

/*
 * Given a 64-bit response, decode to our card SCR structure.
 */
static void mmc_decode_scr(struct mmc_card *card)
{
	struct sd_scr *scr = &card->scr;
	unsigned int scr_struct;
	u32 resp[4];

	BUG_ON(!mmc_card_sd(card));

	resp[3] = card->raw_scr[1];
	resp[2] = card->raw_scr[0];

	scr_struct = UNSTUFF_BITS(resp, 60, 4);
	if (scr_struct != 0) {
		printk("%s: unrecognised SCR structure version %d\n",
			mmc_hostname(card->host), scr_struct);
		mmc_card_set_bad(card);
		return;
	}

	scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4);
	scr->bus_widths = UNSTUFF_BITS(resp, 48, 4);
}

/*
 * Locate a MMC card on this MMC host given a raw CID.
 */
static struct mmc_card *mmc_find_card(struct mmc_host *host, u32 *raw_cid)
{
	struct mmc_card *card;

	list_for_each_entry(card, &host->cards, node) {
		if (memcmp(card->raw_cid, raw_cid, sizeof(card->raw_cid)) == 0)
			return card;
	}
	return NULL;
}

/*
 * Allocate a new MMC card, and assign a unique RCA.
 */
static struct mmc_card *
mmc_alloc_card(struct mmc_host *host, u32 *raw_cid, unsigned int *frca)
{
	struct mmc_card *card, *c;
	unsigned int rca = *frca;

	card = kmalloc(sizeof(struct mmc_card), GFP_KERNEL);
	if (!card)
		return ERR_PTR(-ENOMEM);

	mmc_init_card(card, host);
	memcpy(card->raw_cid, raw_cid, sizeof(card->raw_cid));

 again:
	list_for_each_entry(c, &host->cards, node)
		if (c->rca == rca) {
			rca++;
			goto again;
		}

	card->rca = rca;

	*frca = rca;

	return card;
}

/*
 * Tell attached cards to go to IDLE state
 */
static void mmc_idle_cards(struct mmc_host *host)
{
	struct mmc_command cmd;

	host->ios.chip_select = MMC_CS_HIGH;
	mmc_set_ios(host);

	mmc_delay(1);

	cmd.opcode = MMC_GO_IDLE_STATE;
	cmd.arg = 0;
	cmd.flags = MMC_RSP_NONE | MMC_CMD_BC;

	mmc_wait_for_cmd(host, &cmd, 0);

	mmc_delay(1);

	host->ios.chip_select = MMC_CS_DONTCARE;
	mmc_set_ios(host);

	mmc_delay(1);
}

/*
 * Apply power to the MMC stack.  This is a two-stage process.
 * First, we enable power to the card without the clock running.
 * We then wait a bit for the power to stabilise.  Finally,
 * enable the bus drivers and clock to the card.
 *
 * We must _NOT_ enable the clock prior to power stablising.
 *
 * If a host does all the power sequencing itself, ignore the
 * initial MMC_POWER_UP stage.
 */
static void mmc_power_up(struct mmc_host *host)
{
	int bit = fls(host->ocr_avail) - 1;

	host->ios.vdd = bit;
	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
	host->ios.chip_select = MMC_CS_DONTCARE;
	host->ios.power_mode = MMC_POWER_UP;
	host->ios.bus_width = MMC_BUS_WIDTH_1;
	mmc_set_ios(host);

	mmc_delay(1);

	host->ios.clock = host->f_min;
	host->ios.power_mode = MMC_POWER_ON;
	mmc_set_ios(host);

	mmc_delay(2);
}

static void mmc_power_off(struct mmc_host *host)
{
	host->ios.clock = 0;
	host->ios.vdd = 0;
	host->ios.bus_mode = MMC_BUSMODE_OPENDRAIN;
	host->ios.chip_select = MMC_CS_DONTCARE;
	host->ios.power_mode = MMC_POWER_OFF;
	host->ios.bus_width = MMC_BUS_WIDTH_1;
	mmc_set_ios(host);
}

static int mmc_send_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
{
	struct mmc_command cmd;
	int i, err = 0;

	cmd.opcode = MMC_SEND_OP_COND;
	cmd.arg = ocr;
	cmd.flags = MMC_RSP_R3 | MMC_CMD_BCR;

	for (i = 100; i; i--) {
		err = mmc_wait_for_cmd(host, &cmd, 0);
		if (err != MMC_ERR_NONE)
			break;

		if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
			break;

		err = MMC_ERR_TIMEOUT;

		mmc_delay(10);
	}

	if (rocr)
		*rocr = cmd.resp[0];

	return err;
}

static int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
{
	struct mmc_command cmd;
	int i, err = 0;

	cmd.opcode = SD_APP_OP_COND;
	cmd.arg = ocr;
	cmd.flags = MMC_RSP_R3 | MMC_CMD_BCR;

	for (i = 100; i; i--) {
		err = mmc_wait_for_app_cmd(host, 0, &cmd, CMD_RETRIES);
		if (err != MMC_ERR_NONE)
			break;

		if (cmd.resp[0] & MMC_CARD_BUSY || ocr == 0)
			break;

		err = MMC_ERR_TIMEOUT;

		mmc_delay(10);
	}

	if (rocr)
		*rocr = cmd.resp[0];

	return err;
}

/*
 * Discover cards by requesting their CID.  If this command
 * times out, it is not an error; there are no further cards
 * to be discovered.  Add new cards to the list.
 *
 * Create a mmc_card entry for each discovered card, assigning
 * it an RCA, and save the raw CID for decoding later.
 */
static void mmc_discover_cards(struct mmc_host *host)
{
	struct mmc_card *card;
	unsigned int first_rca = 1, err;

	while (1) {
		struct mmc_command cmd;

		cmd.opcode = MMC_ALL_SEND_CID;
		cmd.arg = 0;
		cmd.flags = MMC_RSP_R2 | MMC_CMD_BCR;

		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
		if (err == MMC_ERR_TIMEOUT) {
			err = MMC_ERR_NONE;
			break;
		}
		if (err != MMC_ERR_NONE) {
			printk(KERN_ERR "%s: error requesting CID: %d\n",
				mmc_hostname(host), err);
			break;
		}

		card = mmc_find_card(host, cmd.resp);
		if (!card) {
			card = mmc_alloc_card(host, cmd.resp, &first_rca);
			if (IS_ERR(card)) {
				err = PTR_ERR(card);
				break;
			}
			list_add(&card->node, &host->cards);
		}

		card->state &= ~MMC_STATE_DEAD;

		if (host->mode == MMC_MODE_SD) {
			mmc_card_set_sd(card);

			cmd.opcode = SD_SEND_RELATIVE_ADDR;
			cmd.arg = 0;
			cmd.flags = MMC_RSP_R6 | MMC_CMD_BCR;

			err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
			if (err != MMC_ERR_NONE)
				mmc_card_set_dead(card);
			else {
				card->rca = cmd.resp[0] >> 16;

				if (!host->ops->get_ro) {
					printk(KERN_WARNING "%s: host does not "
						"support reading read-only "
						"switch. assuming write-enable.\n",
						mmc_hostname(host));
				} else {
					if (host->ops->get_ro(host))
						mmc_card_set_readonly(card);
				}
			}
		} else {
			cmd.opcode = MMC_SET_RELATIVE_ADDR;
			cmd.arg = card->rca << 16;
			cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;

			err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
			if (err != MMC_ERR_NONE)
				mmc_card_set_dead(card);
		}
	}
}

static void mmc_read_csds(struct mmc_host *host)
{
	struct mmc_card *card;

	list_for_each_entry(card, &host->cards, node) {
		struct mmc_command cmd;
		int err;

		if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
			continue;

		cmd.opcode = MMC_SEND_CSD;
		cmd.arg = card->rca << 16;
		cmd.flags = MMC_RSP_R2 | MMC_CMD_AC;

		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
		if (err != MMC_ERR_NONE) {
			mmc_card_set_dead(card);
			continue;
		}

		memcpy(card->raw_csd, cmd.resp, sizeof(card->raw_csd));

		mmc_decode_csd(card);
		mmc_decode_cid(card);
	}
}

static void mmc_process_ext_csds(struct mmc_host *host)
{
	int err;
	struct mmc_card *card;

	struct mmc_request mrq;
	struct mmc_command cmd;
	struct mmc_data data;

	struct scatterlist sg;

	/*
	 * As the ext_csd is so large and mostly unused, we don't store the
	 * raw block in mmc_card.
	 */
	u8 *ext_csd;
	ext_csd = kmalloc(512, GFP_KERNEL);
	if (!ext_csd) {
		printk("%s: could not allocate a buffer to receive the ext_csd."
		       "mmc v4 cards will be treated as v3.\n",
			mmc_hostname(host));
		return;
	}

	list_for_each_entry(card, &host->cards, node) {
		if (card->state & (MMC_STATE_DEAD|MMC_STATE_PRESENT))
			continue;
		if (mmc_card_sd(card))
			continue;
		if (card->csd.mmca_vsn < CSD_SPEC_VER_4)
			continue;

		err = mmc_select_card(host, card);
		if (err != MMC_ERR_NONE) {
			mmc_card_set_dead(card);
			continue;
		}

		memset(&cmd, 0, sizeof(struct mmc_command));

		cmd.opcode = MMC_SEND_EXT_CSD;
		cmd.arg = 0;
		cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;

		memset(&data, 0, sizeof(struct mmc_data));

		mmc_set_data_timeout(&data, card, 0);

		data.blksz = 512;
		data.blocks = 1;
		data.flags = MMC_DATA_READ;
		data.sg = &sg;
		data.sg_len = 1;

		memset(&mrq, 0, sizeof(struct mmc_request));

		mrq.cmd = &cmd;
		mrq.data = &data;

		sg_init_one(&sg, ext_csd, 512);

		mmc_wait_for_req(host, &mrq);

		if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) {
			mmc_card_set_dead(card);
			continue;
		}

		switch (ext_csd[EXT_CSD_CARD_TYPE]) {
		case EXT_CSD_CARD_TYPE_52 | EXT_CSD_CARD_TYPE_26:
			card->ext_csd.hs_max_dtr = 52000000;
			break;
		case EXT_CSD_CARD_TYPE_26:
			card->ext_csd.hs_max_dtr = 26000000;
			break;
		default:
			/* MMC v4 spec says this cannot happen */
			printk("%s: card is mmc v4 but doesn't support "
			       "any high-speed modes.\n",
				mmc_hostname(card->host));
			mmc_card_set_bad(card);
			continue;
		}

		/* Activate highspeed support. */
		cmd.opcode = MMC_SWITCH;
		cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
			  (EXT_CSD_HS_TIMING << 16) |
			  (1 << 8) |
			  EXT_CSD_CMD_SET_NORMAL;
		cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;

		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
		if (err != MMC_ERR_NONE) {
			printk("%s: failed to switch card to mmc v4 "
			       "high-speed mode.\n",
			       mmc_hostname(card->host));
			continue;
		}

		mmc_card_set_highspeed(card);

		/* Check for host support for wide-bus modes. */
		if (!(host->caps & MMC_CAP_4_BIT_DATA)) {
			continue;
		}

		/* Activate 4-bit support. */
		cmd.opcode = MMC_SWITCH;
		cmd.arg = (MMC_SWITCH_MODE_WRITE_BYTE << 24) |
			  (EXT_CSD_BUS_WIDTH << 16) |
			  (EXT_CSD_BUS_WIDTH_4 << 8) |
			  EXT_CSD_CMD_SET_NORMAL;
		cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;

		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
		if (err != MMC_ERR_NONE) {
			printk("%s: failed to switch card to "
			       "mmc v4 4-bit bus mode.\n",
			       mmc_hostname(card->host));
			continue;
		}

		host->ios.bus_width = MMC_BUS_WIDTH_4;
	}