mmc: core: Add mmc_set_blockcount feature

Provide support for automatically sending Set Block Count
(CMD23) messages. Used at least for RPMB support.
Signed-off-by: Alex Macro <alex.macro@stericsson.com>
Signed-off-by: Loic Pallardy <loic.pallardy@stericsson.com>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Johan Rudholm <johan.rudholm@stericsson.com>
Acked-by: Krishna Konda <kkonda@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

@@ -1958,6 +1958,20 @@ int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen)
 }
 EXPORT_SYMBOL(mmc_set_blocklen);
 
+int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,
+			bool is_rel_write)
+{
+	struct mmc_command cmd = {0};
+
+	cmd.opcode = MMC_SET_BLOCK_COUNT;
+	cmd.arg = blockcount & 0x0000FFFF;
+	if (is_rel_write)
+		cmd.arg |= 1 << 31;
+	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+	return mmc_wait_for_cmd(card->host, &cmd, 5);
+}
+EXPORT_SYMBOL(mmc_set_blockcount);
+
 static void mmc_hw_reset_for_init(struct mmc_host *host)
 {
 	if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)

include/linux/mmc/core.h

@@ -170,6 +170,8 @@ extern int mmc_erase_group_aligned(struct mmc_card *card, unsigned int from,
 extern unsigned int mmc_calc_max_discard(struct mmc_card *card);
 
 extern int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen);
+extern int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,
+			      bool is_rel_write);
 extern int mmc_hw_reset(struct mmc_host *host);
 extern int mmc_hw_reset_check(struct mmc_host *host);
 extern int mmc_can_reset(struct mmc_card *card);