mmc: add mmc card sleep and awake support

Add support for the new MMC command SLEEP_AWAKE.

Signed-off-by: Jarkko Lavinen <[e-mail]>
Signed-off-by: Adrian Hunter <[e-mail]>
Acked-by: Matt Fleming <[e-mail]>
Cc: Ian Molton <[e-mail]>
Cc: "Roberto A. Foglietta" <[e-mail]>
Cc: Jarkko Lavinen <[e-mail]>
Cc: Denis Karpov <[e-mail]>
Cc: Pierre Ossman <[e-mail]>
Cc: Philip Langdale <[e-mail]>
Cc: "Madhusudhan" <[e-mail]>
Cc: <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/mmc/core/core.c

···
 }
 EXPORT_SYMBOL(mmc_power_restore_host);
 
+int mmc_card_awake(struct mmc_host *host)
+{
+	int err = -ENOSYS;
+
+	mmc_bus_get(host);
+
+	if (host->bus_ops && !host->bus_dead && host->bus_ops->awake)
+		err = host->bus_ops->awake(host);
+
+	mmc_bus_put(host);
+
+	return err;
+}
+EXPORT_SYMBOL(mmc_card_awake);
+
+int mmc_card_sleep(struct mmc_host *host)
+{
+	int err = -ENOSYS;
+
+	mmc_bus_get(host);
+
+	if (host->bus_ops && !host->bus_dead && host->bus_ops->awake)
+		err = host->bus_ops->sleep(host);
+
+	mmc_bus_put(host);
+
+	return err;
+}
+EXPORT_SYMBOL(mmc_card_sleep);
+
+int mmc_card_can_sleep(struct mmc_host *host)
+{
+	struct mmc_card *card = host->card;
+
+	if (card && mmc_card_mmc(card) && card->ext_csd.rev >= 3)
+		return 1;
+	return 0;
+}
+EXPORT_SYMBOL(mmc_card_can_sleep);
+
 #ifdef CONFIG_PM
 
 /**

drivers/mmc/core/core.h

···
 #define MMC_CMD_RETRIES        3
 
 struct mmc_bus_ops {
+	int (*awake)(struct mmc_host *);
+	int (*sleep)(struct mmc_host *);
 	void (*remove)(struct mmc_host *);
 	void (*detect)(struct mmc_host *);
 	void (*suspend)(struct mmc_host *);

drivers/mmc/core/mmc.c

···
 {
 	int err;
 	u8 *ext_csd;
-	unsigned int ext_csd_struct;
 
 	BUG_ON(!card);
 
···
 		goto out;
 	}
 
-	ext_csd_struct = ext_csd[EXT_CSD_REV];
-	if (ext_csd_struct > 3) {
+	card->ext_csd.rev = ext_csd[EXT_CSD_REV];
+	if (card->ext_csd.rev > 3) {
 		printk(KERN_ERR "%s: unrecognised EXT_CSD structure "
 			"version %d\n", mmc_hostname(card->host),
-			ext_csd_struct);
+			card->ext_csd.rev);
 		err = -EINVAL;
 		goto out;
 	}
 
-	if (ext_csd_struct >= 2) {
+	if (card->ext_csd.rev >= 2) {
 		card->ext_csd.sectors =
 			ext_csd[EXT_CSD_SEC_CNT + 0] << 0 |
 			ext_csd[EXT_CSD_SEC_CNT + 1] << 8 |
···
 			"support any high-speed modes.\n",
 			mmc_hostname(card->host));
 		goto out;
+	}
+
+	if (card->ext_csd.rev >= 3) {
+		u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];
+
+		/* Sleep / awake timeout in 100ns units */
+		if (sa_shift > 0 && sa_shift <= 0x17)
+			card->ext_csd.sa_timeout =
+					1 << ext_csd[EXT_CSD_S_A_TIMEOUT];
 	}
 
 out:
···
 	mmc_release_host(host);
 }
 
+static int mmc_sleep(struct mmc_host *host)
+{
+	struct mmc_card *card = host->card;
+	int err = -ENOSYS;
+
+	if (card && card->ext_csd.rev >= 3) {
+		err = mmc_card_sleepawake(host, 1);
+		if (err < 0)
+			pr_debug("%s: Error %d while putting card into sleep",
+				 mmc_hostname(host), err);
+	}
+
+	return err;
+}
+
+static int mmc_awake(struct mmc_host *host)
+{
+	struct mmc_card *card = host->card;
+	int err = -ENOSYS;
+
+	if (card && card->ext_csd.rev >= 3) {
+		err = mmc_card_sleepawake(host, 0);
+		if (err < 0)
+			pr_debug("%s: Error %d while awaking sleeping card",
+				 mmc_hostname(host), err);
+	}
+
+	return err;
+}
+
 #ifdef CONFIG_MMC_UNSAFE_RESUME
 
 static const struct mmc_bus_ops mmc_ops = {
+	.awake = mmc_awake,
+	.sleep = mmc_sleep,
 	.remove = mmc_remove,
 	.detect = mmc_detect,
 	.suspend = mmc_suspend,
···
 #else
 
 static const struct mmc_bus_ops mmc_ops = {
+	.awake = mmc_awake,
+	.sleep = mmc_sleep,
 	.remove = mmc_remove,
 	.detect = mmc_detect,
 	.suspend = NULL,
···
 };
 
 static const struct mmc_bus_ops mmc_ops_unsafe = {
+	.awake = mmc_awake,
+	.sleep = mmc_sleep,
 	.remove = mmc_remove,
 	.detect = mmc_detect,
 	.suspend = mmc_suspend,

drivers/mmc/core/mmc_ops.c

···
 	return _mmc_select_card(host, NULL);
 }
 
+int mmc_card_sleepawake(struct mmc_host *host, int sleep)
+{
+	struct mmc_command cmd;
+	struct mmc_card *card = host->card;
+	int err;
+
+	if (sleep)
+		mmc_deselect_cards(host);
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+
+	cmd.opcode = MMC_SLEEP_AWAKE;
+	cmd.arg = card->rca << 16;
+	if (sleep)
+		cmd.arg |= 1 << 15;
+
+	cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
+	err = mmc_wait_for_cmd(host, &cmd, 0);
+	if (err)
+		return err;
+
+	/*
+	 * If the host does not wait while the card signals busy, then we will
+	 * will have to wait the sleep/awake timeout.  Note, we cannot use the
+	 * SEND_STATUS command to poll the status because that command (and most
+	 * others) is invalid while the card sleeps.
+	 */
+	if (!(host->caps & MMC_CAP_WAIT_WHILE_BUSY))
+		mmc_delay(DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000));
+
+	if (!sleep)
+		err = mmc_select_card(card);
+
+	return err;
+}
+
 int mmc_go_idle(struct mmc_host *host)
 {
 	int err;

drivers/mmc/core/mmc_ops.h

···
 int mmc_send_cid(struct mmc_host *host, u32 *cid);
 int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp);
 int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
+int mmc_card_sleepawake(struct mmc_host *host, int sleep);
 
 #endif
 

include/linux/mmc/card.h

···
 };
 
 struct mmc_ext_csd {
+	u8			rev;
+	unsigned int		sa_timeout;		/* Units: 100ns */
 	unsigned int		hs_max_dtr;
 	unsigned int		sectors;
 };

include/linux/mmc/host.h

···
 #define MMC_CAP_8_BIT_DATA	(1 << 6)	/* Can the host do 8 bit transfers */
 #define MMC_CAP_DISABLE		(1 << 7)	/* Can the host be disabled */
 #define MMC_CAP_NONREMOVABLE	(1 << 8)	/* Nonremovable e.g. eMMC */
+#define MMC_CAP_WAIT_WHILE_BUSY	(1 << 9)	/* Waits while card is busy */
 
 	/* host specific block data */
 	unsigned int		max_seg_size;	/* see blk_queue_max_segment_size */
···
 
 int mmc_regulator_get_ocrmask(struct regulator *supply);
 int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit);
+
+int mmc_card_awake(struct mmc_host *host);
+int mmc_card_sleep(struct mmc_host *host);
+int mmc_card_can_sleep(struct mmc_host *host);
 
 int mmc_host_enable(struct mmc_host *host);
 int mmc_host_disable(struct mmc_host *host);

include/linux/mmc/mmc.h

···
 #define MMC_ALL_SEND_CID          2   /* bcr                     R2  */
 #define MMC_SET_RELATIVE_ADDR     3   /* ac   [31:16] RCA        R1  */
 #define MMC_SET_DSR               4   /* bc   [31:16] RCA            */
+#define MMC_SLEEP_AWAKE		  5   /* ac   [31:16] RCA 15:flg R1b */
 #define MMC_SWITCH                6   /* ac   [31:0] See below   R1b */
 #define MMC_SELECT_CARD           7   /* ac   [31:16] RCA        R1  */
 #define MMC_SEND_EXT_CSD          8   /* adtc                    R1  */
···
 #define EXT_CSD_CARD_TYPE	196	/* RO */
 #define EXT_CSD_REV		192	/* RO */
 #define EXT_CSD_SEC_CNT		212	/* RO, 4 bytes */
+#define EXT_CSD_S_A_TIMEOUT	217
 
 /*
  * EXT_CSD field definitions