[SCSI] add scsi changer driver

This patch adds a device driver for scsi media changer devices.

Signed-off-by: Gerd Knorr <kraxel@bytesex.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

3 files changed, 172 insertions, 0 deletions

diff --git a/include/linux/chio.h b/include/linux/chio.h
new file mode 100644
index 0000000..63035ae
--- /dev/null
+++ b/include/linux/chio.h
@@ -0,0 +1,168 @@
+/*
+ * ioctl interface for the scsi media changer driver
+ */
+
+/* changer element types */
+#define CHET_MT   0	/* media transport element (robot) */
+#define CHET_ST   1	/* storage element (media slots) */
+#define CHET_IE   2	/* import/export element */
+#define CHET_DT   3	/* data transfer element (tape/cdrom/whatever) */
+#define CHET_V1   4	/* vendor specific #1 */
+#define CHET_V2   5	/* vendor specific #2 */
+#define CHET_V3   6	/* vendor specific #3 */
+#define CHET_V4   7	/* vendor specific #4 */
+
+
+/*
+ * CHIOGPARAMS
+ *    query changer properties
+ *
+ * CHIOVGPARAMS
+ *    query vendor-specific element types
+ *
+ *    accessing elements works by specifing type and unit of the element.
+ *    for eample, storage elements are addressed with type = CHET_ST and
+ *    unit = 0 .. cp_nslots-1
+ *
+ */
+struct changer_params {
+	int cp_curpicker;  /* current transport element */
+	int cp_npickers;   /* number of transport elements      (CHET_MT) */
+	int cp_nslots;     /* number of storage elements        (CHET_ST) */
+	int cp_nportals;   /* number of import/export elements  (CHET_IE) */
+	int cp_ndrives;    /* number of data transfer elements  (CHET_DT) */
+};
+struct changer_vendor_params {
+	int  cvp_n1;       /* number of vendor specific elems   (CHET_V1) */
+	char cvp_label1[16];
+	int  cvp_n2;       /* number of vendor specific elems   (CHET_V2) */
+	char cvp_label2[16];
+	int  cvp_n3;       /* number of vendor specific elems   (CHET_V3) */
+	char cvp_label3[16];
+	int  cvp_n4;       /* number of vendor specific elems   (CHET_V4) */
+	char cvp_label4[16];
+	int  reserved[8];
+};
+
+
+/*
+ * CHIOMOVE
+ *    move a medium from one element to another
+ */
+struct changer_move {
+	int cm_fromtype;	/* type/unit of source element */
+	int cm_fromunit;	
+	int cm_totype;	/* type/unit of destination element */
+	int cm_tounit;
+	int cm_flags;
+};
+#define CM_INVERT   1   /* flag: rotate media (for double-sided like MOD) */
+
+
+/*
+ * CHIOEXCHANGE
+ *    move one medium from element #1 to element #2,
+ *    and another one from element #2 to element #3.
+ *    element #1 and #3 are allowed to be identical.
+ */
+struct changer_exchange {
+	int ce_srctype;	    /* type/unit of element #1 */
+	int ce_srcunit;
+	int ce_fdsttype;    /* type/unit of element #2 */
+	int ce_fdstunit;
+	int ce_sdsttype;    /* type/unit of element #3 */
+	int ce_sdstunit;
+	int ce_flags;
+};
+#define CE_INVERT1   1
+#define CE_INVERT2   2
+
+
+/*
+ * CHIOPOSITION
+ *    move the transport element (robot arm) to a specific element.
+ */
+struct changer_position {
+	int cp_type;
+	int cp_unit;
+	int cp_flags;
+};
+#define CP_INVERT   1
+
+
+/*
+ * CHIOGSTATUS
+ *    get element status for all elements of a specific type
+ */
+struct changer_element_status {
+	int             ces_type;
+	unsigned char   *ces_data;
+};
+#define CESTATUS_FULL     0x01 /* full */
+#define CESTATUS_IMPEXP   0x02	/* media was imported (inserted by sysop) */
+#define CESTATUS_EXCEPT   0x04	/* error condition */
+#define CESTATUS_ACCESS   0x08	/* access allowed */
+#define CESTATUS_EXENAB   0x10	/* element can export media */
+#define CESTATUS_INENAB   0x20	/* element can import media */
+
+
+/*
+ * CHIOGELEM
+ *    get more detailed status informtion for a single element
+ */
+struct changer_get_element {
+	int	cge_type;	 /* type/unit */
+	int	cge_unit;
+	int	cge_status;      /* status */
+	int     cge_errno;       /* errno */
+	int     cge_srctype;     /* source element of the last move/exchange */
+	int     cge_srcunit;
+	int     cge_id;          /* scsi id  (for data transfer elements) */
+	int     cge_lun;         /* scsi lun (for data transfer elements) */
+	char    cge_pvoltag[36]; /* primary volume tag */
+	char    cge_avoltag[36]; /* alternate volume tag */
+	int     cge_flags;
+};
+/* flags */
+#define CGE_ERRNO     0x01       /* errno available       */
+#define CGE_INVERT    0x02       /* media inverted        */
+#define CGE_SRC       0x04       /* media src available   */
+#define CGE_IDLUN     0x08       /* ID+LUN available      */
+#define CGE_PVOLTAG   0x10       /* primary volume tag available */
+#define CGE_AVOLTAG   0x20       /* alternate volume tag available */
+
+
+/*
+ * CHIOSVOLTAG
+ *    set volume tag
+ */
+struct changer_set_voltag {
+	int	csv_type;	 /* type/unit */
+	int	csv_unit;
+	char    csv_voltag[36];  /* volume tag */
+	int     csv_flags;
+};
+#define CSV_PVOLTAG   0x01       /* primary volume tag */
+#define CSV_AVOLTAG   0x02       /* alternate volume tag */
+#define CSV_CLEARTAG  0x04       /* clear volume tag */
+
+/* ioctls */
+#define CHIOMOVE       _IOW('c', 1,struct changer_move)
+#define CHIOEXCHANGE   _IOW('c', 2,struct changer_exchange)
+#define CHIOPOSITION   _IOW('c', 3,struct changer_position)
+#define CHIOGPICKER    _IOR('c', 4,int)                        /* not impl. */
+#define CHIOSPICKER    _IOW('c', 5,int)                        /* not impl. */
+#define CHIOGPARAMS    _IOR('c', 6,struct changer_params)
+#define CHIOGSTATUS    _IOW('c', 8,struct changer_element_status)
+#define CHIOGELEM      _IOW('c',16,struct changer_get_element)
+#define CHIOINITELEM   _IO('c',17)
+#define CHIOSVOLTAG    _IOW('c',18,struct changer_set_voltag)
+#define CHIOGVPARAMS   _IOR('c',19,struct changer_vendor_params)
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * Local variables:
+ * c-basic-offset: 8
+ * End:
+ */
diff --git a/include/linux/major.h b/include/linux/major.h
index 4b62c42..e36a467 100644
--- a/include/linux/major.h
+++ b/include/linux/major.h
@@ -100,6 +100,7 @@
 #define I2O_MAJOR		80	/* 80->87 */
 
 #define SHMIQ_MAJOR		85   /* Linux/mips, SGI /dev/shmiq */
+#define SCSI_CHANGER_MAJOR      86
 
 #define IDE6_MAJOR		88
 #define IDE7_MAJOR		89
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 659ecf4..ca1e3b4 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -41,6 +41,7 @@ extern const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE];
 #define FORMAT_UNIT           0x04
 #define READ_BLOCK_LIMITS     0x05
 #define REASSIGN_BLOCKS       0x07
+#define INITIALIZE_ELEMENT_STATUS 0x07
 #define READ_6                0x08
 #define WRITE_6               0x0a
 #define SEEK_6                0x0b
@@ -65,6 +66,7 @@ extern const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE];
 #define READ_10               0x28
 #define WRITE_10              0x2a
 #define SEEK_10               0x2b
+#define POSITION_TO_ELEMENT   0x2b
 #define WRITE_VERIFY          0x2e
 #define VERIFY                0x2f
 #define SEARCH_HIGH           0x30
@@ -97,6 +99,7 @@ extern const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE];
 #define PERSISTENT_RESERVE_OUT 0x5f
 #define REPORT_LUNS           0xa0
 #define MOVE_MEDIUM           0xa5
+#define EXCHANGE_MEDIUM       0xa6
 #define READ_12               0xa8
 #define WRITE_12              0xaa
 #define WRITE_VERIFY_12       0xae