1 files changed, 115 insertions, 53 deletions

diff --git a/drivers/ata/sata_sx4.c b/drivers/ata/sata_sx4.c
index 2d14f3d56d92..5193bd8647ba 100644
--- a/drivers/ata/sata_sx4.c
+++ b/drivers/ata/sata_sx4.c
@@ -30,6 +30,54 @@
  *
  */
 
+/*
+        Theory of operation
+        -------------------
+
+        The SX4 (PDC20621) chip features a single Host DMA (HDMA) copy
+        engine, DIMM memory, and four ATA engines (one per SATA port).
+        Data is copied to/from DIMM memory by the HDMA engine, before
+        handing off to one (or more) of the ATA engines.  The ATA
+        engines operate solely on DIMM memory.
+
+        The SX4 behaves like a PATA chip, with no SATA controls or
+        knowledge whatsoever, leading to the presumption that
+        PATA<->SATA bridges exist on SX4 boards, external to the
+        PDC20621 chip itself.
+
+        The chip is quite capable, supporting an XOR engine and linked
+        hardware commands (permits a string to transactions to be
+        submitted and waited-on as a single unit), and an optional
+        microprocessor.
+
+        The limiting factor is largely software.  This Linux driver was
+        written to multiplex the single HDMA engine to copy disk
+        transactions into a fixed DIMM memory space, from where an ATA
+        engine takes over.  As a result, each WRITE looks like this:
+
+                submit HDMA packet to hardware
+                hardware copies data from system memory to DIMM
+                hardware raises interrupt
+
+                submit ATA packet to hardware
+                hardware executes ATA WRITE command, w/ data in DIMM
+                hardware raises interrupt
+        
+        and each READ looks like this:
+
+                submit ATA packet to hardware
+                hardware executes ATA READ command, w/ data in DIMM
+                hardware raises interrupt
+        
+                submit HDMA packet to hardware
+                hardware copies data from DIMM to system memory
+                hardware raises interrupt
+
+        This is a very slow, lock-step way of doing things that can
+        certainly be improved by motivated kernel hackers.
+
+ */
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
@@ -58,6 +106,8 @@ enum {
         PDC_INT_SEQMASK         = 0x40, /* Mask of asserted SEQ INTs */
         PDC_HDMA_CTLSTAT        = 0x12C, /* Host DMA control / status */
 
+        PDC_CTLSTAT             = 0x60, /* IDEn control / status */
+
         PDC_20621_SEQCTL        = 0x400,
         PDC_20621_SEQMASK       = 0x480,
         PDC_20621_GENERAL_CTL   = 0x484,
@@ -87,48 +137,60 @@ enum {
 
         board_20621             = 0,    /* FastTrak S150 SX4 */
 
-        PDC_RESET               = (1 << 11), /* HDMA reset */
+        PDC_MASK_INT            = (1 << 10), /* HDMA/ATA mask int */
+        PDC_RESET               = (1 << 11), /* HDMA/ATA reset */
+        PDC_DMA_ENABLE          = (1 << 7),  /* DMA start/stop */
 
         PDC_MAX_HDMA            = 32,
         PDC_HDMA_Q_MASK         = (PDC_MAX_HDMA - 1),
 
-        PDC_DIMM0_SPD_DEV_ADDRESS     = 0x50,
-        PDC_DIMM1_SPD_DEV_ADDRESS     = 0x51,
-        PDC_MAX_DIMM_MODULE           = 0x02,
-        PDC_I2C_CONTROL_OFFSET        = 0x48,
-        PDC_I2C_ADDR_DATA_OFFSET      = 0x4C,
-        PDC_DIMM0_CONTROL_OFFSET      = 0x80,
-        PDC_DIMM1_CONTROL_OFFSET      = 0x84,
-        PDC_SDRAM_CONTROL_OFFSET      = 0x88,
-        PDC_I2C_WRITE                 = 0x00000000,
-        PDC_I2C_READ                  = 0x00000040,
-        PDC_I2C_START                 = 0x00000080,
-        PDC_I2C_MASK_INT              = 0x00000020,
-        PDC_I2C_COMPLETE              = 0x00010000,
-        PDC_I2C_NO_ACK                = 0x00100000,
-        PDC_DIMM_SPD_SUBADDRESS_START = 0x00,
-        PDC_DIMM_SPD_SUBADDRESS_END   = 0x7F,
-        PDC_DIMM_SPD_ROW_NUM          = 3,
-        PDC_DIMM_SPD_COLUMN_NUM       = 4,
-        PDC_DIMM_SPD_MODULE_ROW       = 5,
-        PDC_DIMM_SPD_TYPE             = 11,
-        PDC_DIMM_SPD_FRESH_RATE       = 12,
-        PDC_DIMM_SPD_BANK_NUM         = 17,
-        PDC_DIMM_SPD_CAS_LATENCY      = 18,
-        PDC_DIMM_SPD_ATTRIBUTE        = 21,
-        PDC_DIMM_SPD_ROW_PRE_CHARGE   = 27,
-        PDC_DIMM_SPD_ROW_ACTIVE_DELAY = 28,
-        PDC_DIMM_SPD_RAS_CAS_DELAY    = 29,
-        PDC_DIMM_SPD_ACTIVE_PRECHARGE = 30,
-        PDC_DIMM_SPD_SYSTEM_FREQ      = 126,
-        PDC_CTL_STATUS                = 0x08,
-        PDC_DIMM_WINDOW_CTLR          = 0x0C,
-        PDC_TIME_CONTROL              = 0x3C,
-        PDC_TIME_PERIOD               = 0x40,
-        PDC_TIME_COUNTER              = 0x44,
-        PDC_GENERAL_CTLR              = 0x484,
-        PCI_PLL_INIT                  = 0x8A531824,
-        PCI_X_TCOUNT                  = 0xEE1E5CFF
+        PDC_DIMM0_SPD_DEV_ADDRESS       = 0x50,
+        PDC_DIMM1_SPD_DEV_ADDRESS       = 0x51,
+        PDC_I2C_CONTROL                 = 0x48,
+        PDC_I2C_ADDR_DATA               = 0x4C,
+        PDC_DIMM0_CONTROL               = 0x80,
+        PDC_DIMM1_CONTROL               = 0x84,
+        PDC_SDRAM_CONTROL               = 0x88,
+        PDC_I2C_WRITE                   = 0,            /* master -> slave */
+        PDC_I2C_READ                    = (1 << 6),     /* master <- slave */
+        PDC_I2C_START                   = (1 << 7),     /* start I2C proto */
+        PDC_I2C_MASK_INT                = (1 << 5),     /* mask I2C interrupt */
+        PDC_I2C_COMPLETE                = (1 << 16),    /* I2C normal compl. */
+        PDC_I2C_NO_ACK                  = (1 << 20),    /* slave no-ack addr */
+        PDC_DIMM_SPD_SUBADDRESS_START   = 0x00,
+        PDC_DIMM_SPD_SUBADDRESS_END     = 0x7F,
+        PDC_DIMM_SPD_ROW_NUM            = 3,
+        PDC_DIMM_SPD_COLUMN_NUM         = 4,
+        PDC_DIMM_SPD_MODULE_ROW         = 5,
+        PDC_DIMM_SPD_TYPE               = 11,
+        PDC_DIMM_SPD_FRESH_RATE         = 12,
+        PDC_DIMM_SPD_BANK_NUM           = 17,
+        PDC_DIMM_SPD_CAS_LATENCY        = 18,
+        PDC_DIMM_SPD_ATTRIBUTE          = 21,
+        PDC_DIMM_SPD_ROW_PRE_CHARGE     = 27,
+        PDC_DIMM_SPD_ROW_ACTIVE_DELAY   = 28,
+        PDC_DIMM_SPD_RAS_CAS_DELAY      = 29,
+        PDC_DIMM_SPD_ACTIVE_PRECHARGE   = 30,
+        PDC_DIMM_SPD_SYSTEM_FREQ        = 126,
+        PDC_CTL_STATUS                  = 0x08,
+        PDC_DIMM_WINDOW_CTLR            = 0x0C,
+        PDC_TIME_CONTROL                = 0x3C,
+        PDC_TIME_PERIOD                 = 0x40,
+        PDC_TIME_COUNTER                = 0x44,
+        PDC_GENERAL_CTLR                = 0x484,
+        PCI_PLL_INIT                    = 0x8A531824,
+        PCI_X_TCOUNT                    = 0xEE1E5CFF,
+
+        /* PDC_TIME_CONTROL bits */
+        PDC_TIMER_BUZZER                = (1 << 10),
+        PDC_TIMER_MODE_PERIODIC         = 0,            /* bits 9:8 == 00 */
+        PDC_TIMER_MODE_ONCE             = (1 << 8),     /* bits 9:8 == 01 */
+        PDC_TIMER_ENABLE                = (1 << 7),
+        PDC_TIMER_MASK_INT              = (1 << 5),
+        PDC_TIMER_SEQ_MASK              = 0x1f,         /* SEQ ID for timer */
+        PDC_TIMER_DEFAULT               = PDC_TIMER_MODE_ONCE |
+                                          PDC_TIMER_ENABLE |
+                                          PDC_TIMER_MASK_INT,
 };
 
 
@@ -217,7 +279,7 @@ static const struct ata_port_info pdc_port_info[] = {
                                   ATA_FLAG_NO_ATAPI | ATA_FLAG_PIO_POLLING,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
-                .udma_mask      = 0x7f, /* udma0-6 ; FIXME */
+                .udma_mask      = ATA_UDMA6,
                 .port_ops       = &pdc_20621_ops,
         },
 
@@ -999,17 +1061,17 @@ static unsigned int pdc20621_i2c_read(struct ata_host *host, u32 device,
         i2creg |= subaddr << 16;
 
         /* Set the device and subaddress */
-        writel(i2creg, mmio + PDC_I2C_ADDR_DATA_OFFSET);
-        readl(mmio + PDC_I2C_ADDR_DATA_OFFSET);
+        writel(i2creg, mmio + PDC_I2C_ADDR_DATA);
+        readl(mmio + PDC_I2C_ADDR_DATA);
 
         /* Write Control to perform read operation, mask int */
         writel(PDC_I2C_READ | PDC_I2C_START | PDC_I2C_MASK_INT,
-               mmio + PDC_I2C_CONTROL_OFFSET);
+               mmio + PDC_I2C_CONTROL);
 
         for (count = 0; count <= 1000; count ++) {
-                status = readl(mmio + PDC_I2C_CONTROL_OFFSET);
+                status = readl(mmio + PDC_I2C_CONTROL);
                 if (status & PDC_I2C_COMPLETE) {
-                        status = readl(mmio + PDC_I2C_ADDR_DATA_OFFSET);
+                        status = readl(mmio + PDC_I2C_ADDR_DATA);
                         break;
                 } else if (count == 1000)
                         return 0;
@@ -1099,8 +1161,8 @@ static int pdc20621_prog_dimm0(struct ata_host *host)
         data |= (((size / 16) - 1) << 16);
         data |= (0 << 23);
         data |= 8;
-        writel(data, mmio + PDC_DIMM0_CONTROL_OFFSET);
-        readl(mmio + PDC_DIMM0_CONTROL_OFFSET);
+        writel(data, mmio + PDC_DIMM0_CONTROL);
+        readl(mmio + PDC_DIMM0_CONTROL);
         return size;
 }
 
@@ -1122,27 +1184,27 @@ static unsigned int pdc20621_prog_dimm_global(struct ata_host *host)
         */
 
         data = 0x022259F1;
-        writel(data, mmio + PDC_SDRAM_CONTROL_OFFSET);
-        readl(mmio + PDC_SDRAM_CONTROL_OFFSET);
+        writel(data, mmio + PDC_SDRAM_CONTROL);
+        readl(mmio + PDC_SDRAM_CONTROL);
 
         /* Turn on for ECC */
         pdc20621_i2c_read(host, PDC_DIMM0_SPD_DEV_ADDRESS,
                           PDC_DIMM_SPD_TYPE, &spd0);
         if (spd0 == 0x02) {
                 data |= (0x01 << 16);
-                writel(data, mmio + PDC_SDRAM_CONTROL_OFFSET);
-                readl(mmio + PDC_SDRAM_CONTROL_OFFSET);
+                writel(data, mmio + PDC_SDRAM_CONTROL);
+                readl(mmio + PDC_SDRAM_CONTROL);
                 printk(KERN_ERR "Local DIMM ECC Enabled\n");
         }
 
         /* DIMM Initialization Select/Enable (bit 18/19) */
         data &= (~(1<<18));
         data |= (1<<19);
-        writel(data, mmio + PDC_SDRAM_CONTROL_OFFSET);
+        writel(data, mmio + PDC_SDRAM_CONTROL);
 
         error = 1;
         for (i = 1; i <= 10; i++) {   /* polling ~5 secs */
-                data = readl(mmio + PDC_SDRAM_CONTROL_OFFSET);
+                data = readl(mmio + PDC_SDRAM_CONTROL);
                 if (!(data & (1<<19))) {
                         error = 0;
                         break;
@@ -1176,7 +1238,7 @@ static unsigned int pdc20621_dimm_init(struct ata_host *host)
         VPRINTK("Time Period Register (0x40): 0x%x\n", time_period);
 
         /* Enable timer */
-        writel(0x00001a0, mmio + PDC_TIME_CONTROL);
+        writel(PDC_TIMER_DEFAULT, mmio + PDC_TIME_CONTROL);
         readl(mmio + PDC_TIME_CONTROL);
 
         /* Wait 3 seconds */