+ /*
+ * 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;
+ }
+
+ kfree(ext_csd);
+
+ mmc_deselect_cards(host);
+}
+
+static void mmc_read_scrs(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;
+