MMC headers learn about SPI

Teach the MMC/SD/SDIO system headers that some hosts use SPI mode

 - New host capabilities and status bits
    * MMC_CAP_SPI, with mmc_host_is_spi() test
    * mmc_host.use_spi_crc flag

 - SPI-specific declarations:
    * Response types, MMC_RSP_SPI_R*
    * Two SPI-only commands
    * Status bits used native to SPI:  R1_SPI_*, R2_SPI_*

 - Fix a few (unrelated) whitespace bugs in the headers.

 - Reorder a few mmc_host fields, removing several bytes of padding

None of these changes affect current code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

3 files changed, 67 insertions, 13 deletions

diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 8945da9b54fa..d0c3abed74c2 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -25,14 +25,20 @@ struct mmc_command {
 #define MMC_RSP_CRC     (1 << 2)                /* expect valid crc */
 #define MMC_RSP_BUSY    (1 << 3)                /* card may send busy */
 #define MMC_RSP_OPCODE  (1 << 4)                /* response contains opcode */
-#define MMC_CMD_MASK    (3 << 5)                /* command type */
+
+#define MMC_CMD_MASK    (3 << 5)                /* non-SPI command type */
 #define MMC_CMD_AC      (0 << 5)
 #define MMC_CMD_ADTC    (1 << 5)
 #define MMC_CMD_BC      (2 << 5)
 #define MMC_CMD_BCR     (3 << 5)
 
+#define MMC_RSP_SPI_S1  (1 << 7)                /* one status byte */
+#define MMC_RSP_SPI_S2  (1 << 8)                /* second byte */
+#define MMC_RSP_SPI_B4  (1 << 9)                /* four data bytes */
+#define MMC_RSP_SPI_BUSY (1 << 10)              /* card may send busy */
+
 /*
- * These are the response types, and correspond to valid bit
+ * These are the native response types, and correspond to valid bit
  * patterns of the above flags.  One additional valid pattern
  * is all zeros, which means we don't expect a response.
  */
@@ -49,6 +55,22 @@ struct mmc_command {
 #define mmc_resp_type(cmd)      ((cmd)->flags & (MMC_RSP_PRESENT|MMC_RSP_136|MMC_RSP_CRC|MMC_RSP_BUSY|MMC_RSP_OPCODE))
 
 /*
+ * These are the SPI response types for MMC, SD, and SDIO cards.
+ * Commands return R1, with maybe more info.  Zero is an error type;
+ * callers must always provide the appropriate MMC_RSP_SPI_Rx flags.
+ */
+#define MMC_RSP_SPI_R1  (MMC_RSP_SPI_S1)
+#define MMC_RSP_SPI_R1B (MMC_RSP_SPI_S1|MMC_RSP_SPI_BUSY)
+#define MMC_RSP_SPI_R2  (MMC_RSP_SPI_S1|MMC_RSP_SPI_S2)
+#define MMC_RSP_SPI_R3  (MMC_RSP_SPI_S1|MMC_RSP_SPI_B4)
+#define MMC_RSP_SPI_R4  (MMC_RSP_SPI_S1|MMC_RSP_SPI_B4)
+#define MMC_RSP_SPI_R5  (MMC_RSP_SPI_S1|MMC_RSP_SPI_S2)
+#define MMC_RSP_SPI_R7  (MMC_RSP_SPI_S1|MMC_RSP_SPI_B4)
+
+#define mmc_spi_resp_type(cmd)  ((cmd)->flags & \
+                (MMC_RSP_SPI_S1|MMC_RSP_SPI_BUSY|MMC_RSP_SPI_S2|MMC_RSP_SPI_B4))
+
+/*
  * These are the command types.
  */
 #define mmc_cmd_type(cmd)       ((cmd)->flags & MMC_CMD_MASK)
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 3fd197962f73..76eef94782f8 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -91,6 +91,7 @@ struct mmc_host {
 #define MMC_CAP_MMC_HIGHSPEED   (1 << 2)        /* Can do MMC high-speed timing */
 #define MMC_CAP_SD_HIGHSPEED    (1 << 3)        /* Can do SD high-speed timing */
 #define MMC_CAP_SDIO_IRQ        (1 << 4)        /* Can signal pending SDIO IRQs */
+#define MMC_CAP_SPI             (1 << 5)        /* Talks only SPI protocols */
 
         /* host specific block data */
         unsigned int            max_seg_size;   /* see blk_queue_max_segment_size */
@@ -107,6 +108,14 @@ struct mmc_host {
         struct mmc_ios          ios;            /* current io bus settings */
         u32                     ocr;            /* the current OCR setting */
 
+        /* group bitfields together to minimize padding */
+        unsigned int            use_spi_crc:1;
+        unsigned int            claimed:1;      /* host exclusively claimed */
+        unsigned int            bus_dead:1;     /* bus has been released */
+#ifdef CONFIG_MMC_DEBUG
+        unsigned int            removed:1;      /* host is being removed */
+#endif
+
         unsigned int            mode;           /* current card mode of host */
 #define MMC_MODE_MMC            0
 #define MMC_MODE_SD             1
@@ -114,16 +123,11 @@ struct mmc_host {
         struct mmc_card         *card;          /* device attached to this host */
 
         wait_queue_head_t       wq;
-        unsigned int            claimed:1;      /* host exclusively claimed */
 
         struct delayed_work     detect;
-#ifdef CONFIG_MMC_DEBUG
-        unsigned int            removed:1;      /* host is being removed */
-#endif
 
         const struct mmc_bus_ops *bus_ops;      /* current bus driver */
         unsigned int            bus_refs;       /* reference counter */
-        unsigned int            bus_dead:1;     /* bus has been released */
 
         unsigned int            sdio_irqs;
         struct task_struct      *sdio_irq_thread;
@@ -142,6 +146,8 @@ static inline void *mmc_priv(struct mmc_host *host)
         return (void *)host->private;
 }
 
+#define mmc_host_is_spi(host)   ((host)->caps & MMC_CAP_SPI)
+
 #define mmc_dev(x)      ((x)->parent)
 #define mmc_classdev(x) (&(x)->class_dev)
 #define mmc_hostname(x) ((x)->class_dev.bus_id)
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index d1d6cbcc1514..4236fbf0b6fb 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -27,7 +27,7 @@
 
 /* Standard MMC commands (4.1)           type  argument     response */
    /* class 1 */
-#define MMC_GO_IDLE_STATE         0   /* bc                          */
+#define MMC_GO_IDLE_STATE         0   /* bc                          */
 #define MMC_SEND_OP_COND          1   /* bcr  [31:0] OCR         R3  */
 #define MMC_ALL_SEND_CID          2   /* bcr                     R2  */
 #define MMC_SET_RELATIVE_ADDR     3   /* ac   [31:16] RCA        R1  */
@@ -39,8 +39,10 @@
 #define MMC_SEND_CID             10   /* ac   [31:16] RCA        R2  */
 #define MMC_READ_DAT_UNTIL_STOP  11   /* adtc [31:0] dadr        R1  */
 #define MMC_STOP_TRANSMISSION    12   /* ac                      R1b */
-#define MMC_SEND_STATUS          13   /* ac   [31:16] RCA        R1  */
+#define MMC_SEND_STATUS          13   /* ac   [31:16] RCA        R1  */
 #define MMC_GO_INACTIVE_STATE    15   /* ac   [31:16] RCA            */
+#define MMC_SPI_READ_OCR         58   /* spi                  spi_R3 */
+#define MMC_SPI_CRC_ON_OFF       59   /* spi  [0:0] flag      spi_R1 */
 
   /* class 2 */
 #define MMC_SET_BLOCKLEN         16   /* ac   [31:0] block len   R1  */
@@ -90,15 +92,15 @@
  */
 
 /*
-  MMC status in R1
+  MMC status in R1, for native mode (SPI bits are different)
   Type
-        e : error bit
+        e : error bit
         s : status bit
         r : detected and set for the actual command response
         x : detected and set during command execution. the host must poll
             the card by sending status command in order to read these bits.
   Clear condition
-        a : according to the card state
+        a : according to the card state
         b : always related to the previous command. Reception of
             a valid command will clear it (with a delay of one command)
         c : clear by read
@@ -124,10 +126,33 @@
 #define R1_CARD_ECC_DISABLED    (1 << 14)       /* sx, a */
 #define R1_ERASE_RESET          (1 << 13)       /* sr, c */
 #define R1_STATUS(x)            (x & 0xFFFFE000)
-#define R1_CURRENT_STATE(x)     ((x & 0x00001E00) >> 9) /* sx, b (4 bits) */
+#define R1_CURRENT_STATE(x)     ((x & 0x00001E00) >> 9) /* sx, b (4 bits) */
 #define R1_READY_FOR_DATA       (1 << 8)        /* sx, a */
 #define R1_APP_CMD              (1 << 5)        /* sr, c */
 
+/*
+ * MMC/SD in SPI mode reports R1 status always, and R2 for SEND_STATUS
+ * R1 is the low order byte; R2 is the next highest byte, when present.
+ */
+#define R1_SPI_IDLE             (1 << 0)
+#define R1_SPI_ERASE_RESET      (1 << 1)
+#define R1_SPI_ILLEGAL_COMMAND  (1 << 2)
+#define R1_SPI_COM_CRC          (1 << 3)
+#define R1_SPI_ERASE_SEQ        (1 << 4)
+#define R1_SPI_ADDRESS          (1 << 5)
+#define R1_SPI_PARAMETER        (1 << 6)
+/* R1 bit 7 is always zero */
+#define R2_SPI_CARD_LOCKED      (1 << 8)
+#define R2_SPI_WP_ERASE_SKIP    (1 << 9)        /* or lock/unlock fail */
+#define R2_SPI_LOCK_UNLOCK_FAIL R2_SPI_WP_ERASE_SKIP
+#define R2_SPI_ERROR            (1 << 10)
+#define R2_SPI_CC_ERROR         (1 << 11)
+#define R2_SPI_CARD_ECC_ERROR   (1 << 12)
+#define R2_SPI_WP_VIOLATION     (1 << 13)
+#define R2_SPI_ERASE_PARAM      (1 << 14)
+#define R2_SPI_OUT_OF_RANGE     (1 << 15)       /* or CSD overwrite */
+#define R2_SPI_CSD_OVERWRITE    R2_SPI_OUT_OF_RANGE
+
 /* These are unpacked versions of the actual responses */
 
 struct _mmc_csd {
@@ -182,6 +207,7 @@ struct _mmc_csd {
  */
 #define CCC_BASIC               (1<<0)  /* (0) Basic protocol functions */
                                         /* (CMD0,1,2,3,4,7,9,10,12,13,15) */
+                                        /* (and for SPI, CMD58,59) */
 #define CCC_STREAM_READ         (1<<1)  /* (1) Stream read commands */
                                         /* (CMD11) */
 #define CCC_BLOCK_READ          (1<<2)  /* (2) Block read commands */