mmc: add packed command feature of eMMC4.5

This patch adds packed command feature of eMMC4.5.  The maximum number
for packing read (or write) is offered and exception event relevant to
packed command which is used for error handling is enabled. If host
wants to use this feature, MMC_CAP2_PACKED_CMD should be set.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

4 files changed, 48 insertions, 2 deletions

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 8a3ad602a877..c8f3d6e0684e 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -538,6 +538,11 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 } else {
                         card->ext_csd.data_tag_unit_size = 0;
                 }
+
+                card->ext_csd.max_packed_writes =
+                        ext_csd[EXT_CSD_MAX_PACKED_WRITES];
+                card->ext_csd.max_packed_reads =
+                        ext_csd[EXT_CSD_MAX_PACKED_READS];
         } else {
                 card->ext_csd.data_sector_size = 512;
         }
@@ -1275,6 +1280,29 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
                 }
         }
 
+        /*
+         * The mandatory minimum values are defined for packed command.
+         * read: 5, write: 3
+         */
+        if (card->ext_csd.max_packed_writes >= 3 &&
+            card->ext_csd.max_packed_reads >= 5 &&
+            host->caps2 & MMC_CAP2_PACKED_CMD) {
+                err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+                                EXT_CSD_EXP_EVENTS_CTRL,
+                                EXT_CSD_PACKED_EVENT_EN,
+                                card->ext_csd.generic_cmd6_time);
+                if (err && err != -EBADMSG)
+                        goto free_card;
+                if (err) {
+                        pr_warn("%s: Enabling packed event failed\n",
+                                mmc_hostname(card->host));
+                        card->ext_csd.packed_event_en = 0;
+                        err = 0;
+                } else {
+                        card->ext_csd.packed_event_en = 1;
+                }
+        }
+
         if (!oldcard)
                 host->card = card;
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 7069dcea27c5..237f253f2fe0 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -53,6 +53,9 @@ struct mmc_ext_csd {
         u8                      part_config;
         u8                      cache_ctrl;
         u8                      rst_n_function;
+        u8                      max_packed_writes;
+        u8                      max_packed_reads;
+        u8                      packed_event_en;
         unsigned int            part_time;              /* Units: ms */
         unsigned int            sa_timeout;             /* Units: 100ns */
         unsigned int            generic_cmd6_time;      /* Units: 10ms */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 6c235e03de29..a0466c03f5e1 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -276,6 +276,10 @@ struct mmc_host {
 #define MMC_CAP2_HC_ERASE_SZ    (1 << 9)        /* High-capacity erase size */
 #define MMC_CAP2_CD_ACTIVE_HIGH (1 << 10)       /* Card-detect signal active high */
 #define MMC_CAP2_RO_ACTIVE_HIGH (1 << 11)       /* Write-protect signal active high */
+#define MMC_CAP2_PACKED_RD      (1 << 12)       /* Allow packed read */
+#define MMC_CAP2_PACKED_WR      (1 << 13)       /* Allow packed write */
+#define MMC_CAP2_PACKED_CMD     (MMC_CAP2_PACKED_RD | \
+                                 MMC_CAP2_PACKED_WR)
 
         mmc_pm_flag_t           pm_caps;        /* supported pm features */
 
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 94d532e41c61..50bcde3677ca 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -139,7 +139,7 @@ static inline bool mmc_op_multi(u32 opcode)
 #define R1_CURRENT_STATE(x)     ((x & 0x00001E00) >> 9) /* sx, b (4 bits) */
 #define R1_READY_FOR_DATA       (1 << 8)        /* sx, a */
 #define R1_SWITCH_ERROR         (1 << 7)        /* sx, c */
-#define R1_EXCEPTION_EVENT      (1 << 6)        /* sx, a */
+#define R1_EXCEPTION_EVENT      (1 << 6)        /* sr, a */
 #define R1_APP_CMD              (1 << 5)        /* sr, c */
 
 #define R1_STATE_IDLE   0
@@ -275,7 +275,10 @@ struct _mmc_csd {
 #define EXT_CSD_FLUSH_CACHE             32      /* W */
 #define EXT_CSD_CACHE_CTRL              33      /* R/W */
 #define EXT_CSD_POWER_OFF_NOTIFICATION  34      /* R/W */
-#define EXT_CSD_EXP_EVENTS_STATUS       54      /* RO */
+#define EXT_CSD_PACKED_FAILURE_INDEX    35      /* RO */
+#define EXT_CSD_PACKED_CMD_STATUS       36      /* RO */
+#define EXT_CSD_EXP_EVENTS_STATUS       54      /* RO, 2 bytes */
+#define EXT_CSD_EXP_EVENTS_CTRL         56      /* R/W, 2 bytes */
 #define EXT_CSD_DATA_SECTOR_SIZE        61      /* R */
 #define EXT_CSD_GP_SIZE_MULT            143     /* R/W */
 #define EXT_CSD_PARTITION_ATTRIBUTE     156     /* R/W */
@@ -324,6 +327,8 @@ struct _mmc_csd {
 #define EXT_CSD_CACHE_SIZE              249     /* RO, 4 bytes */
 #define EXT_CSD_TAG_UNIT_SIZE           498     /* RO */
 #define EXT_CSD_DATA_TAG_SUPPORT        499     /* RO */
+#define EXT_CSD_MAX_PACKED_WRITES       500     /* RO */
+#define EXT_CSD_MAX_PACKED_READS        501     /* RO */
 #define EXT_CSD_BKOPS_SUPPORT           502     /* RO */
 #define EXT_CSD_HPI_FEATURES            503     /* RO */
 
@@ -385,6 +390,9 @@ struct _mmc_csd {
 #define EXT_CSD_PWR_CL_4BIT_MASK        0x0F    /* 8 bit PWR CLS */
 #define EXT_CSD_PWR_CL_8BIT_SHIFT       4
 #define EXT_CSD_PWR_CL_4BIT_SHIFT       0
+
+#define EXT_CSD_PACKED_EVENT_EN BIT(3)
+
 /*
  * EXCEPTION_EVENT_STATUS field
  */
@@ -393,6 +401,9 @@ struct _mmc_csd {
 #define EXT_CSD_SYSPOOL_EXHAUSTED       BIT(2)
 #define EXT_CSD_PACKED_FAILURE          BIT(3)
 
+#define EXT_CSD_PACKED_GENERIC_ERROR    BIT(0)
+#define EXT_CSD_PACKED_INDEXED_ERROR    BIT(1)
+
 /*
  * BKOPS status level
  */