m68k: merge mmu and non-mmu versions of processor.h
[linux-2.6.git] / arch / cris / arch-v32 / drivers / sync_serial.c
index d581b0a..d2a0fbf 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Simple synchronous serial port driver for ETRAX FS.
+ * Simple synchronous serial port driver for ETRAX FS and Artpec-3.
  *
  * Copyright (c) 2005 Axis Communications AB
  *
@@ -14,6 +14,7 @@
 #include <linux/major.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/smp_lock.h>
 #include <linux/interrupt.h>
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 
 #include <asm/io.h>
-#include <asm/arch/dma.h>
-#include <asm/arch/pinmux.h>
-#include <asm/arch/hwregs/reg_rdwr.h>
-#include <asm/arch/hwregs/sser_defs.h>
-#include <asm/arch/hwregs/dma_defs.h>
-#include <asm/arch/hwregs/dma.h>
-#include <asm/arch/hwregs/intr_vect_defs.h>
-#include <asm/arch/hwregs/intr_vect.h>
-#include <asm/arch/hwregs/reg_map.h>
+#include <dma.h>
+#include <pinmux.h>
+#include <hwregs/reg_rdwr.h>
+#include <hwregs/sser_defs.h>
+#include <hwregs/dma_defs.h>
+#include <hwregs/dma.h>
+#include <hwregs/intr_vect_defs.h>
+#include <hwregs/intr_vect.h>
+#include <hwregs/reg_map.h>
 #include <asm/sync_serial.h>
 
+
 /* The receiver is a bit tricky beacuse of the continuous stream of data.*/
 /*                                                                       */
 /* Three DMA descriptors are linked together. Each DMA descriptor is     */
 /* words can be handled */
 #define IN_BUFFER_SIZE 12288
 #define IN_DESCR_SIZE 256
-#define NUM_IN_DESCR (IN_BUFFER_SIZE/IN_DESCR_SIZE)
-#define OUT_BUFFER_SIZE 4096
+#define NBR_IN_DESCR (IN_BUFFER_SIZE/IN_DESCR_SIZE)
+
+#define OUT_BUFFER_SIZE 1024*8
+#define NBR_OUT_DESCR 8
 
 #define DEFAULT_FRAME_RATE 0
 #define DEFAULT_WORD_RATE 7
@@ -78,6 +82,8 @@
 #define DEBUGPOLL(x)
 #define DEBUGRXINT(x)
 #define DEBUGTXINT(x)
+#define DEBUGTRDMA(x)
+#define DEBUGOUTBUF(x)
 
 typedef struct sync_port
 {
@@ -97,10 +103,11 @@ typedef struct sync_port
        int output;
        int input;
 
-       volatile unsigned int out_count; /* Remaining bytes for current transfer */
-       unsigned char* outp; /* Current position in out_buffer */
-       volatile unsigned char* volatile readp;  /* Next byte to be read by application */
-       volatile unsigned char* volatile writep; /* Next byte to be written by etrax */
+       /* Next byte to be read by application */
+       volatile unsigned char *volatile readp;
+       /* Next byte to be written by etrax */
+       volatile unsigned char *volatile writep;
+
        unsigned int in_buffer_size;
        unsigned int inbufchunk;
        unsigned char out_buffer[OUT_BUFFER_SIZE] __attribute__ ((aligned(32)));
@@ -108,11 +115,30 @@ typedef struct sync_port
        unsigned char flip[IN_BUFFER_SIZE] __attribute__ ((aligned(32)));
        struct dma_descr_data* next_rx_desc;
        struct dma_descr_data* prev_rx_desc;
+
+       /* Pointer to the first available descriptor in the ring,
+        * unless active_tr_descr == catch_tr_descr and a dma
+        * transfer is active */
+       struct dma_descr_data *active_tr_descr;
+
+       /* Pointer to the first allocated descriptor in the ring */
+       struct dma_descr_data *catch_tr_descr;
+
+       /* Pointer to the descriptor with the current end-of-list */
+       struct dma_descr_data *prev_tr_descr;
        int full;
 
-       dma_descr_data in_descr[NUM_IN_DESCR] __attribute__ ((__aligned__(16)));
+       /* Pointer to the first byte being read by DMA
+        * or current position in out_buffer if not using DMA. */
+       unsigned char *out_rd_ptr;
+
+       /* Number of bytes currently locked for being read by DMA */
+       int out_buf_count;
+
+       dma_descr_data in_descr[NBR_IN_DESCR] __attribute__ ((__aligned__(16)));
        dma_descr_context in_context __attribute__ ((__aligned__(32)));
-       dma_descr_data out_descr __attribute__ ((__aligned__(16)));
+       dma_descr_data out_descr[NBR_OUT_DESCR]
+               __attribute__ ((__aligned__(16)));
        dma_descr_context out_context __attribute__ ((__aligned__(32)));
        wait_queue_head_t out_wait_q;
        wait_queue_head_t in_wait_q;
@@ -143,11 +169,11 @@ static ssize_t sync_serial_read(struct file *file, char *buf,
 #endif
 
 static void send_word(sync_port* port);
-static void start_dma(struct sync_port *port, const char* data, int count);
+static void start_dma_out(struct sync_port *port, const char *data, int count);
 static void start_dma_in(sync_port* port);
 #ifdef SYNC_SER_DMA
-static irqreturn_t tr_interrupt(int irq, void *dev_id, struct pt_regs * regs);
-static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs);
+static irqreturn_t tr_interrupt(int irq, void *dev_id);
+static irqreturn_t rx_interrupt(int irq, void *dev_id);
 #endif
 
 #if (defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT0) && \
@@ -157,22 +183,49 @@ static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs);
 #define SYNC_SER_MANUAL
 #endif
 #ifdef SYNC_SER_MANUAL
-static irqreturn_t manual_interrupt(int irq, void *dev_id, struct pt_regs * regs);
+static irqreturn_t manual_interrupt(int irq, void *dev_id);
+#endif
+
+#ifdef CONFIG_ETRAXFS  /* ETRAX FS */
+#define OUT_DMA_NBR 4
+#define IN_DMA_NBR 5
+#define PINMUX_SSER pinmux_sser0
+#define SYNCSER_INST regi_sser0
+#define SYNCSER_INTR_VECT SSER0_INTR_VECT
+#define OUT_DMA_INST regi_dma4
+#define IN_DMA_INST regi_dma5
+#define DMA_OUT_INTR_VECT DMA4_INTR_VECT
+#define DMA_IN_INTR_VECT DMA5_INTR_VECT
+#define REQ_DMA_SYNCSER dma_sser0
+#else                  /* Artpec-3 */
+#define OUT_DMA_NBR 6
+#define IN_DMA_NBR 7
+#define PINMUX_SSER pinmux_sser
+#define SYNCSER_INST regi_sser
+#define SYNCSER_INTR_VECT SSER_INTR_VECT
+#define OUT_DMA_INST regi_dma6
+#define IN_DMA_INST regi_dma7
+#define DMA_OUT_INTR_VECT DMA6_INTR_VECT
+#define DMA_IN_INTR_VECT DMA7_INTR_VECT
+#define REQ_DMA_SYNCSER dma_sser
 #endif
 
 /* The ports */
 static struct sync_port ports[]=
 {
        {
-               .regi_sser             = regi_sser0,
-               .regi_dmaout           = regi_dma4,
-               .regi_dmain            = regi_dma5,
+               .regi_sser             = SYNCSER_INST,
+               .regi_dmaout           = OUT_DMA_INST,
+               .regi_dmain            = IN_DMA_INST,
 #if defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL0_DMA)
                 .use_dma               = 1,
 #else
                 .use_dma               = 0,
 #endif
-       },
+       }
+#ifdef CONFIG_ETRAXFS
+       ,
+
        {
                .regi_sser             = regi_sser1,
                .regi_dmaout           = regi_dma6,
@@ -183,9 +236,10 @@ static struct sync_port ports[]=
                 .use_dma               = 0,
 #endif
        }
+#endif
 };
 
-#define NUMBER_OF_PORTS ARRAY_SIZE(ports)
+#define NBR_PORTS ARRAY_SIZE(ports)
 
 static const struct file_operations sync_serial_fops = {
        .owner   = THIS_MODULE,
@@ -200,19 +254,21 @@ static const struct file_operations sync_serial_fops = {
 static int __init etrax_sync_serial_init(void)
 {
        ports[0].enabled = 0;
+#ifdef CONFIG_ETRAXFS
        ports[1].enabled = 0;
-
-       if (register_chrdev(SYNC_SERIAL_MAJOR,"sync serial", &sync_serial_fops) <0 )
-       {
-               printk("unable to get major for synchronous serial port\n");
+#endif
+       if (register_chrdev(SYNC_SERIAL_MAJOR, "sync serial",
+                       &sync_serial_fops) < 0) {
+               printk(KERN_WARNING
+                       "Unable to get major for synchronous serial port\n");
                return -EBUSY;
        }
 
        /* Initialize Ports */
 #if defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT0)
-       if (crisv32_pinmux_alloc_fixed(pinmux_sser0))
-       {
-               printk("Unable to allocate pins for syncrhronous serial port 0\n");
+       if (crisv32_pinmux_alloc_fixed(PINMUX_SSER)) {
+               printk(KERN_WARNING
+                       "Unable to alloc pins for synchronous serial port 0\n");
                return -EIO;
        }
        ports[0].enabled = 1;
@@ -220,33 +276,40 @@ static int __init etrax_sync_serial_init(void)
 #endif
 
 #if defined(CONFIG_ETRAX_SYNCHRONOUS_SERIAL_PORT1)
-       if (crisv32_pinmux_alloc_fixed(pinmux_sser1))
-       {
-               printk("Unable to allocate pins for syncrhronous serial port 0\n");
+       if (crisv32_pinmux_alloc_fixed(pinmux_sser1)) {
+               printk(KERN_WARNING
+                       "Unable to alloc pins for synchronous serial port 0\n");
                return -EIO;
        }
        ports[1].enabled = 1;
        initialize_port(1);
 #endif
 
-       printk("ETRAX FS synchronous serial port driver\n");
+#ifdef CONFIG_ETRAXFS
+       printk(KERN_INFO "ETRAX FS synchronous serial port driver\n");
+#else
+       printk(KERN_INFO "Artpec-3 synchronous serial port driver\n");
+#endif
        return 0;
 }
 
 static void __init initialize_port(int portnbr)
 {
-       struct sync_port* port = &ports[portnbr];
+       int __attribute__((unused)) i;
+       struct sync_port *port = &ports[portnbr];
        reg_sser_rw_cfg cfg = {0};
        reg_sser_rw_frm_cfg frm_cfg = {0};
        reg_sser_rw_tr_cfg tr_cfg = {0};
        reg_sser_rw_rec_cfg rec_cfg = {0};
 
-       DEBUG(printk("Init sync serial port %d\n", portnbr));
+       DEBUG(printk(KERN_DEBUG "Init sync serial port %d\n", portnbr));
 
        port->port_nbr = portnbr;
        port->init_irqs = 1;
 
-       port->outp = port->out_buffer;
+       port->out_rd_ptr = port->out_buffer;
+       port->out_buf_count = 0;
+
        port->output = 1;
        port->input = 0;
 
@@ -255,7 +318,7 @@ static void __init initialize_port(int portnbr)
        port->in_buffer_size = IN_BUFFER_SIZE;
        port->inbufchunk = IN_DESCR_SIZE;
        port->next_rx_desc = &port->in_descr[0];
-       port->prev_rx_desc = &port->in_descr[NUM_IN_DESCR-1];
+       port->prev_rx_desc = &port->in_descr[NBR_IN_DESCR-1];
        port->prev_rx_desc->eol = 1;
 
        init_waitqueue_head(&port->out_wait_q);
@@ -286,8 +349,13 @@ static void __init initialize_port(int portnbr)
        tr_cfg.sample_size = 7;
        tr_cfg.sh_dir = regk_sser_msbfirst;
        tr_cfg.use_dma = port->use_dma ? regk_sser_yes : regk_sser_no;
+#if 0
        tr_cfg.rate_ctrl = regk_sser_bulk;
        tr_cfg.data_pin_use = regk_sser_dout;
+#else
+       tr_cfg.rate_ctrl = regk_sser_iso;
+       tr_cfg.data_pin_use = regk_sser_dout;
+#endif
        tr_cfg.bulk_wspace = 1;
        REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
 
@@ -296,6 +364,27 @@ static void __init initialize_port(int portnbr)
        rec_cfg.use_dma = port->use_dma ? regk_sser_yes : regk_sser_no;
        rec_cfg.fifo_thr = regk_sser_inf;
        REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
+
+#ifdef SYNC_SER_DMA
+       /* Setup the descriptor ring for dma out/transmit. */
+       for (i = 0; i < NBR_OUT_DESCR; i++) {
+               port->out_descr[i].wait = 0;
+               port->out_descr[i].intr = 1;
+               port->out_descr[i].eol = 0;
+               port->out_descr[i].out_eop = 0;
+               port->out_descr[i].next =
+                       (dma_descr_data *)virt_to_phys(&port->out_descr[i+1]);
+       }
+
+       /* Create a ring from the list. */
+       port->out_descr[NBR_OUT_DESCR-1].next =
+               (dma_descr_data *)virt_to_phys(&port->out_descr[0]);
+
+       /* Setup context for traversing the ring. */
+       port->active_tr_descr = &port->out_descr[0];
+       port->prev_tr_descr = &port->out_descr[NBR_OUT_DESCR-1];
+       port->catch_tr_descr = &port->out_descr[0];
+#endif
 }
 
 static inline int sync_data_avail(struct sync_port *port)
@@ -311,7 +400,7 @@ static inline int sync_data_avail(struct sync_port *port)
         *  ^rp  ^wp    ^wp ^rp
         */
 
-       if (end >= start)
+       if (end >= start)
                avail = end - start;
        else
                avail = port->in_buffer_size - (start - end);
@@ -331,7 +420,7 @@ static inline int sync_data_avail_to_end(struct sync_port *port)
         *  ^rp  ^wp    ^wp ^rp
         */
 
-       if (end >= start)
+       if (end >= start)
                avail = end - start;
        else
                avail = port->flip + port->in_buffer_size - start;
@@ -341,66 +430,72 @@ static inline int sync_data_avail_to_end(struct sync_port *port)
 static int sync_serial_open(struct inode *inode, struct file *file)
 {
        int dev = iminor(inode);
-       sync_port* port;
+       int ret = -EBUSY;
+       sync_port *port;
        reg_dma_rw_cfg cfg = {.en = regk_dma_yes};
        reg_dma_rw_intr_mask intr_mask = {.data = regk_dma_yes};
 
-       DEBUG(printk("Open sync serial port %d\n", dev));
+       lock_kernel();
+       DEBUG(printk(KERN_DEBUG "Open sync serial port %d\n", dev));
 
-       if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled)
+       if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled)
        {
-               DEBUG(printk("Invalid minor %d\n", dev));
-               return -ENODEV;
+               DEBUG(printk(KERN_DEBUG "Invalid minor %d\n", dev));
+               ret = -ENODEV;
+               goto out;
        }
        port = &ports[dev];
        /* Allow open this device twice (assuming one reader and one writer) */
        if (port->busy == 2)
        {
-               DEBUG(printk("Device is busy.. \n"));
-               return -EBUSY;
+               DEBUG(printk(KERN_DEBUG "Device is busy.. \n"));
+               goto out;
        }
+
+
        if (port->init_irqs) {
                if (port->use_dma) {
-                       if (port == &ports[0]){
+                       if (port == &ports[0]) {
 #ifdef SYNC_SER_DMA
-                               if(request_irq(DMA4_INTR_VECT,
-                                              tr_interrupt,
-                                              0,
-                                              "synchronous serial 0 dma tr",
-                                              &ports[0])) {
+                               if (request_irq(DMA_OUT_INTR_VECT,
+                                               tr_interrupt,
+                                               0,
+                                               "synchronous serial 0 dma tr",
+                                               &ports[0])) {
                                        printk(KERN_CRIT "Can't allocate sync serial port 0 IRQ");
-                                       return -EBUSY;
-                               } else if(request_irq(DMA5_INTR_VECT,
-                                                     rx_interrupt,
-                                                     0,
-                                                     "synchronous serial 1 dma rx",
-                                                     &ports[0])) {
-                                       free_irq(DMA4_INTR_VECT, &port[0]);
+                                       goto out;
+                               } else if (request_irq(DMA_IN_INTR_VECT,
+                                               rx_interrupt,
+                                               0,
+                                               "synchronous serial 1 dma rx",
+                                               &ports[0])) {
+                                       free_irq(DMA_OUT_INTR_VECT, &port[0]);
                                        printk(KERN_CRIT "Can't allocate sync serial port 0 IRQ");
-                                       return -EBUSY;
-                               } else if (crisv32_request_dma(SYNC_SER0_TX_DMA_NBR,
-                                                               "synchronous serial 0 dma tr",
-                                                               DMA_VERBOSE_ON_ERROR,
-                                                               0,
-                                                               dma_sser0)) {
-                                       free_irq(DMA4_INTR_VECT, &port[0]);
-                                       free_irq(DMA5_INTR_VECT, &port[0]);
+                                       goto out;
+                               } else if (crisv32_request_dma(OUT_DMA_NBR,
+                                               "synchronous serial 0 dma tr",
+                                               DMA_VERBOSE_ON_ERROR,
+                                               0,
+                                               REQ_DMA_SYNCSER)) {
+                                       free_irq(DMA_OUT_INTR_VECT, &port[0]);
+                                       free_irq(DMA_IN_INTR_VECT, &port[0]);
                                        printk(KERN_CRIT "Can't allocate sync serial port 0 TX DMA channel");
-                                       return -EBUSY;
-                               } else if (crisv32_request_dma(SYNC_SER0_RX_DMA_NBR,
-                                                               "synchronous serial 0 dma rec",
-                                                               DMA_VERBOSE_ON_ERROR,
-                                                               0,
-                                                               dma_sser0)) {
-                                       crisv32_free_dma(SYNC_SER0_TX_DMA_NBR);
-                                       free_irq(DMA4_INTR_VECT, &port[0]);
-                                       free_irq(DMA5_INTR_VECT, &port[0]);
+                                       goto out;
+                               } else if (crisv32_request_dma(IN_DMA_NBR,
+                                               "synchronous serial 0 dma rec",
+                                               DMA_VERBOSE_ON_ERROR,
+                                               0,
+                                               REQ_DMA_SYNCSER)) {
+                                       crisv32_free_dma(OUT_DMA_NBR);
+                                       free_irq(DMA_OUT_INTR_VECT, &port[0]);
+                                       free_irq(DMA_IN_INTR_VECT, &port[0]);
                                        printk(KERN_CRIT "Can't allocate sync serial port 1 RX DMA channel");
-                                       return -EBUSY;
+                                       goto out;
                                }
 #endif
                        }
-                       else if (port == &ports[1]){
+#ifdef CONFIG_ETRAXFS
+                       else if (port == &ports[1]) {
 #ifdef SYNC_SER_DMA
                                if (request_irq(DMA6_INTR_VECT,
                                                tr_interrupt,
@@ -408,7 +503,7 @@ static int sync_serial_open(struct inode *inode, struct file *file)
                                                "synchronous serial 1 dma tr",
                                                &ports[1])) {
                                        printk(KERN_CRIT "Can't allocate sync serial port 1 IRQ");
-                                       return -EBUSY;
+                                       goto out;
                                } else if (request_irq(DMA7_INTR_VECT,
                                                       rx_interrupt,
                                                       0,
@@ -416,37 +511,39 @@ static int sync_serial_open(struct inode *inode, struct file *file)
                                                       &ports[1])) {
                                        free_irq(DMA6_INTR_VECT, &ports[1]);
                                        printk(KERN_CRIT "Can't allocate sync serial port 3 IRQ");
-                                       return -EBUSY;
-                               } else if (crisv32_request_dma(SYNC_SER1_TX_DMA_NBR,
-                                                               "synchronous serial 1 dma tr",
-                                                               DMA_VERBOSE_ON_ERROR,
-                                                               0,
-                                                               dma_sser1)) {
-                                       free_irq(21, &ports[1]);
-                                       free_irq(20, &ports[1]);
+                                       goto out;
+                               } else if (crisv32_request_dma(
+                                               SYNC_SER1_TX_DMA_NBR,
+                                               "synchronous serial 1 dma tr",
+                                               DMA_VERBOSE_ON_ERROR,
+                                               0,
+                                               dma_sser1)) {
+                                       free_irq(DMA6_INTR_VECT, &ports[1]);
+                                       free_irq(DMA7_INTR_VECT, &ports[1]);
                                        printk(KERN_CRIT "Can't allocate sync serial port 3 TX DMA channel");
-                                       return -EBUSY;
-                               } else if (crisv32_request_dma(SYNC_SER1_RX_DMA_NBR,
-                                                           "synchronous serial 3 dma rec",
-                                                           DMA_VERBOSE_ON_ERROR,
-                                                           0,
-                                                           dma_sser1)) {
+                                       goto out;
+                               } else if (crisv32_request_dma(
+                                               SYNC_SER1_RX_DMA_NBR,
+                                               "synchronous serial 3 dma rec",
+                                               DMA_VERBOSE_ON_ERROR,
+                                               0,
+                                               dma_sser1)) {
                                        crisv32_free_dma(SYNC_SER1_TX_DMA_NBR);
                                        free_irq(DMA6_INTR_VECT, &ports[1]);
                                        free_irq(DMA7_INTR_VECT, &ports[1]);
                                        printk(KERN_CRIT "Can't allocate sync serial port 3 RX DMA channel");
-                                       return -EBUSY;
+                                       goto out;
                                }
 #endif
                        }
-
+#endif
                         /* Enable DMAs */
                        REG_WR(dma, port->regi_dmain, rw_cfg, cfg);
                        REG_WR(dma, port->regi_dmaout, rw_cfg, cfg);
                        /* Enable DMA IRQs */
                        REG_WR(dma, port->regi_dmain, rw_intr_mask, intr_mask);
                        REG_WR(dma, port->regi_dmaout, rw_intr_mask, intr_mask);
-                       /* Set up wordsize = 2 for DMAs. */
+                       /* Set up wordsize = 1 for DMAs. */
                        DMA_WR_CMD (port->regi_dmain, regk_dma_set_w_size1);
                        DMA_WR_CMD (port->regi_dmaout, regk_dma_set_w_size1);
 
@@ -455,41 +552,48 @@ static int sync_serial_open(struct inode *inode, struct file *file)
                } else { /* !port->use_dma */
 #ifdef SYNC_SER_MANUAL
                        if (port == &ports[0]) {
-                               if (request_irq(SSER0_INTR_VECT,
+                               if (request_irq(SYNCSER_INTR_VECT,
                                                manual_interrupt,
                                                0,
                                                "synchronous serial manual irq",
                                                &ports[0])) {
                                        printk("Can't allocate sync serial manual irq");
-                                       return -EBUSY;
+                                       goto out;
                                }
-                       } else if (port == &ports[1]) {
+                       }
+#ifdef CONFIG_ETRAXFS
+                       else if (port == &ports[1]) {
                                if (request_irq(SSER1_INTR_VECT,
                                                manual_interrupt,
                                                0,
                                                "synchronous serial manual irq",
                                                &ports[1])) {
                                        printk(KERN_CRIT "Can't allocate sync serial manual irq");
-                                       return -EBUSY;
+                                       goto out;
                                }
                        }
+#endif
                        port->init_irqs = 0;
 #else
                        panic("sync_serial: Manual mode not supported.\n");
 #endif /* SYNC_SER_MANUAL */
                }
+
        } /* port->init_irqs */
 
        port->busy++;
-       return 0;
+       ret = 0;
+out:
+       unlock_kernel();
+       return ret;
 }
 
 static int sync_serial_release(struct inode *inode, struct file *file)
 {
        int dev = iminor(inode);
-       sync_port* port;
+       sync_port *port;
 
-       if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled)
+       if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled)
        {
                DEBUG(printk("Invalid minor %d\n", dev));
                return -ENODEV;
@@ -506,17 +610,37 @@ static unsigned int sync_serial_poll(struct file *file, poll_table *wait)
 {
        int dev = iminor(file->f_path.dentry->d_inode);
        unsigned int mask = 0;
-       sync_port* port;
+       sync_port *port;
        DEBUGPOLL( static unsigned int prev_mask = 0; );
 
        port = &ports[dev];
+
+       if (!port->started) {
+               reg_sser_rw_cfg cfg = REG_RD(sser, port->regi_sser, rw_cfg);
+               reg_sser_rw_rec_cfg rec_cfg =
+                       REG_RD(sser, port->regi_sser, rw_rec_cfg);
+               cfg.en = regk_sser_yes;
+               rec_cfg.rec_en = port->input;
+               REG_WR(sser, port->regi_sser, rw_cfg, cfg);
+               REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
+               port->started = 1;
+       }
+
        poll_wait(file, &port->out_wait_q, wait);
        poll_wait(file, &port->in_wait_q, wait);
-       /* Some room to write */
-       if (port->out_count < OUT_BUFFER_SIZE)
+
+       /* No active transfer, descriptors are available */
+       if (port->output && !port->tr_running)
+               mask |= POLLOUT | POLLWRNORM;
+
+       /* Descriptor and buffer space available. */
+       if (port->output &&
+           port->active_tr_descr != port->catch_tr_descr &&
+           port->out_buf_count < OUT_BUFFER_SIZE)
                mask |=  POLLOUT | POLLWRNORM;
+
        /* At least an inbufchunk of data */
-       if (sync_data_avail(port) >= port->inbufchunk)
+       if (port->input && sync_data_avail(port) >= port->inbufchunk)
                mask |= POLLIN | POLLRDNORM;
 
        DEBUGPOLL(if (mask != prev_mask)
@@ -531,15 +655,16 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
                  unsigned int cmd, unsigned long arg)
 {
        int return_val = 0;
+       int dma_w_size = regk_dma_set_w_size1;
        int dev = iminor(file->f_path.dentry->d_inode);
-       sync_port* port;
+       sync_port *port;
        reg_sser_rw_tr_cfg tr_cfg;
        reg_sser_rw_rec_cfg rec_cfg;
        reg_sser_rw_frm_cfg frm_cfg;
        reg_sser_rw_cfg gen_cfg;
        reg_sser_rw_intr_mask intr_mask;
 
-       if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled)
+       if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled)
        {
                DEBUG(printk("Invalid minor %d\n", dev));
                return -1;
@@ -558,61 +683,81 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
        case SSP_SPEED:
                if (GET_SPEED(arg) == CODEC)
                {
+                       unsigned int freq;
+
                        gen_cfg.base_freq = regk_sser_f32;
-                       /* FREQ = 0 => 4 MHz => clk_div = 7*/
-                       gen_cfg.clk_div = 6 + (1 << GET_FREQ(arg));
-               }
-               else
-               {
+
+                       /* Clock divider will internally be
+                        * gen_cfg.clk_div + 1.
+                        */
+
+                       freq = GET_FREQ(arg);
+                       switch (freq) {
+                       case FREQ_32kHz:
+                       case FREQ_64kHz:
+                       case FREQ_128kHz:
+                       case FREQ_256kHz:
+                               gen_cfg.clk_div = 125 *
+                                       (1 << (freq - FREQ_256kHz)) - 1;
+                       break;
+                       case FREQ_512kHz:
+                               gen_cfg.clk_div = 62;
+                       break;
+                       case FREQ_1MHz:
+                       case FREQ_2MHz:
+                       case FREQ_4MHz:
+                               gen_cfg.clk_div = 8 * (1 << freq) - 1;
+                       break;
+                       }
+               } else {
                        gen_cfg.base_freq = regk_sser_f29_493;
-                       switch (GET_SPEED(arg))
-                       {
-                               case SSP150:
-                                       gen_cfg.clk_div = 29493000 / (150 * 8) - 1;
-                                       break;
-                               case SSP300:
-                                       gen_cfg.clk_div = 29493000 / (300 * 8) - 1;
-                                       break;
-                               case SSP600:
-                                       gen_cfg.clk_div = 29493000 / (600 * 8) - 1;
-                                       break;
-                               case SSP1200:
-                                       gen_cfg.clk_div = 29493000 / (1200 * 8) - 1;
-                                       break;
-                               case SSP2400:
-                                       gen_cfg.clk_div = 29493000 / (2400 * 8) - 1;
-                                       break;
-                               case SSP4800:
-                                       gen_cfg.clk_div = 29493000 / (4800 * 8) - 1;
-                                       break;
-                               case SSP9600:
-                                       gen_cfg.clk_div = 29493000 / (9600 * 8) - 1;
-                                       break;
-                               case SSP19200:
-                                       gen_cfg.clk_div = 29493000 / (19200 * 8) - 1;
-                                       break;
-                               case SSP28800:
-                                       gen_cfg.clk_div = 29493000 / (28800 * 8) - 1;
-                                       break;
-                               case SSP57600:
-                                       gen_cfg.clk_div = 29493000 / (57600 * 8) - 1;
-                                       break;
-                               case SSP115200:
-                                       gen_cfg.clk_div = 29493000 / (115200 * 8) - 1;
-                                       break;
-                               case SSP230400:
-                                       gen_cfg.clk_div = 29493000 / (230400 * 8) - 1;
-                                       break;
-                               case SSP460800:
-                                       gen_cfg.clk_div = 29493000 / (460800 * 8) - 1;
-                                       break;
-                               case SSP921600:
-                                       gen_cfg.clk_div = 29493000 / (921600 * 8) - 1;
-                                       break;
-                               case SSP3125000:
-                                       gen_cfg.base_freq = regk_sser_f100;
-                                       gen_cfg.clk_div = 100000000 / (3125000 * 8) - 1;
-                                       break;
+                       switch (GET_SPEED(arg)) {
+                       case SSP150:
+                               gen_cfg.clk_div = 29493000 / (150 * 8) - 1;
+                               break;
+                       case SSP300:
+                               gen_cfg.clk_div = 29493000 / (300 * 8) - 1;
+                               break;
+                       case SSP600:
+                               gen_cfg.clk_div = 29493000 / (600 * 8) - 1;
+                               break;
+                       case SSP1200:
+                               gen_cfg.clk_div = 29493000 / (1200 * 8) - 1;
+                               break;
+                       case SSP2400:
+                               gen_cfg.clk_div = 29493000 / (2400 * 8) - 1;
+                               break;
+                       case SSP4800:
+                               gen_cfg.clk_div = 29493000 / (4800 * 8) - 1;
+                               break;
+                       case SSP9600:
+                               gen_cfg.clk_div = 29493000 / (9600 * 8) - 1;
+                               break;
+                       case SSP19200:
+                               gen_cfg.clk_div = 29493000 / (19200 * 8) - 1;
+                               break;
+                       case SSP28800:
+                               gen_cfg.clk_div = 29493000 / (28800 * 8) - 1;
+                               break;
+                       case SSP57600:
+                               gen_cfg.clk_div = 29493000 / (57600 * 8) - 1;
+                               break;
+                       case SSP115200:
+                               gen_cfg.clk_div = 29493000 / (115200 * 8) - 1;
+                               break;
+                       case SSP230400:
+                               gen_cfg.clk_div = 29493000 / (230400 * 8) - 1;
+                               break;
+                       case SSP460800:
+                               gen_cfg.clk_div = 29493000 / (460800 * 8) - 1;
+                               break;
+                       case SSP921600:
+                               gen_cfg.clk_div = 29493000 / (921600 * 8) - 1;
+                               break;
+                       case SSP3125000:
+                               gen_cfg.base_freq = regk_sser_f100;
+                               gen_cfg.clk_div = 100000000 / (3125000 * 8) - 1;
+                               break;
 
                        }
                }
@@ -625,46 +770,60 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
                        case MASTER_OUTPUT:
                                port->output = 1;
                                port->input = 0;
+                               frm_cfg.out_on = regk_sser_tr;
+                               frm_cfg.frame_pin_dir = regk_sser_out;
                                gen_cfg.clk_dir = regk_sser_out;
                                break;
                        case SLAVE_OUTPUT:
                                port->output = 1;
                                port->input = 0;
+                               frm_cfg.frame_pin_dir = regk_sser_in;
                                gen_cfg.clk_dir = regk_sser_in;
                                break;
                        case MASTER_INPUT:
                                port->output = 0;
                                port->input = 1;
+                               frm_cfg.frame_pin_dir = regk_sser_out;
+                               frm_cfg.out_on = regk_sser_intern_tb;
                                gen_cfg.clk_dir = regk_sser_out;
                                break;
                        case SLAVE_INPUT:
                                port->output = 0;
                                port->input = 1;
+                               frm_cfg.frame_pin_dir = regk_sser_in;
                                gen_cfg.clk_dir = regk_sser_in;
                                break;
                        case MASTER_BIDIR:
                                port->output = 1;
                                port->input = 1;
+                               frm_cfg.frame_pin_dir = regk_sser_out;
+                               frm_cfg.out_on = regk_sser_intern_tb;
                                gen_cfg.clk_dir = regk_sser_out;
                                break;
                        case SLAVE_BIDIR:
                                port->output = 1;
                                port->input = 1;
+                               frm_cfg.frame_pin_dir = regk_sser_in;
                                gen_cfg.clk_dir = regk_sser_in;
                                break;
                        default:
                                spin_unlock_irq(&port->lock);
                                return -EINVAL;
-
                }
                if (!port->use_dma || (arg == MASTER_OUTPUT || arg == SLAVE_OUTPUT))
                        intr_mask.rdav = regk_sser_yes;
                break;
        case SSP_FRAME_SYNC:
-               if (arg & NORMAL_SYNC)
+               if (arg & NORMAL_SYNC) {
+                       frm_cfg.rec_delay = 1;
                        frm_cfg.tr_delay = 1;
+               }
                else if (arg & EARLY_SYNC)
-                       frm_cfg.tr_delay = 0;
+                       frm_cfg.rec_delay = frm_cfg.tr_delay = 0;
+               else if (arg & SECOND_WORD_SYNC) {
+                       frm_cfg.rec_delay = 7;
+                       frm_cfg.tr_delay = 1;
+               }
 
                tr_cfg.bulk_wspace = frm_cfg.tr_delay;
                frm_cfg.early_wend = regk_sser_yes;
@@ -680,9 +839,11 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
                else if (arg & SYNC_OFF)
                        frm_cfg.frame_pin_use = regk_sser_gio0;
 
-               if (arg & WORD_SIZE_8)
+               dma_w_size = regk_dma_set_w_size2;
+               if (arg & WORD_SIZE_8) {
                        rec_cfg.sample_size = tr_cfg.sample_size = 7;
-               else if (arg & WORD_SIZE_12)
+                       dma_w_size = regk_dma_set_w_size1;
+               } else if (arg & WORD_SIZE_12)
                        rec_cfg.sample_size = tr_cfg.sample_size = 11;
                else if (arg & WORD_SIZE_16)
                        rec_cfg.sample_size = tr_cfg.sample_size = 15;
@@ -696,10 +857,13 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
                else if (arg & BIT_ORDER_LSB)
                        rec_cfg.sh_dir = tr_cfg.sh_dir = regk_sser_lsbfirst;
 
-               if (arg & FLOW_CONTROL_ENABLE)
+               if (arg & FLOW_CONTROL_ENABLE) {
+                       frm_cfg.status_pin_use = regk_sser_frm;
                        rec_cfg.fifo_thr = regk_sser_thr16;
-               else if (arg & FLOW_CONTROL_DISABLE)
+               } else if (arg & FLOW_CONTROL_DISABLE) {
+                       frm_cfg.status_pin_use = regk_sser_gio0;
                        rec_cfg.fifo_thr = regk_sser_inf;
+               }
 
                if (arg & CLOCK_NOT_GATED)
                        gen_cfg.gate_clk = regk_sser_no;
@@ -726,9 +890,9 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
                break;
        case SSP_OPOLARITY:
                if (arg & CLOCK_NORMAL)
-                       gen_cfg.out_clk_pol = regk_sser_neg;
-               else if (arg & CLOCK_INVERT)
                        gen_cfg.out_clk_pol = regk_sser_pos;
+               else if (arg & CLOCK_INVERT)
+                       gen_cfg.out_clk_pol = regk_sser_neg;
 
                if (arg & FRAME_NORMAL)
                        frm_cfg.level = regk_sser_pos_hi;
@@ -770,10 +934,9 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
        }
 
 
-       if (port->started)
-       {
-               tr_cfg.tr_en = port->output;
+       if (port->started) {
                rec_cfg.rec_en = port->input;
+               gen_cfg.en = (port->output | port->input);
        }
 
        REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
@@ -782,138 +945,145 @@ static int sync_serial_ioctl(struct inode *inode, struct file *file,
        REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
        REG_WR(sser, port->regi_sser, rw_cfg, gen_cfg);
 
+
+       if (cmd == SSP_FRAME_SYNC && (arg & (WORD_SIZE_8 | WORD_SIZE_12 |
+                       WORD_SIZE_16 | WORD_SIZE_24 | WORD_SIZE_32))) {
+               int en = gen_cfg.en;
+               gen_cfg.en = 0;
+               REG_WR(sser, port->regi_sser, rw_cfg, gen_cfg);
+               /* ##### Should DMA be stoped before we change dma size? */
+               DMA_WR_CMD(port->regi_dmain, dma_w_size);
+               DMA_WR_CMD(port->regi_dmaout, dma_w_size);
+               gen_cfg.en = en;
+               REG_WR(sser, port->regi_sser, rw_cfg, gen_cfg);
+       }
+
        spin_unlock_irq(&port->lock);
        return return_val;
 }
 
-static ssize_t sync_serial_write(struct file * file, const char * buf,
-                                 size_t count, loff_t *ppos)
+/* NOTE: sync_serial_write does not support concurrency */
+static ssize_t sync_serial_write(struct file *file, const char *buf,
+                                size_t count, loff_t *ppos)
 {
        int dev = iminor(file->f_path.dentry->d_inode);
        DECLARE_WAITQUEUE(wait, current);
-       sync_port *port;
-       unsigned long c, c1;
-       unsigned long free_outp;
-       unsigned long outp;
-       unsigned long out_buffer;
+       struct sync_port *port;
+       int trunc_count;
        unsigned long flags;
+       int bytes_free;
+       int out_buf_count;
 
-       if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled)
-       {
+       unsigned char *rd_ptr;       /* First allocated byte in the buffer */
+       unsigned char *wr_ptr;       /* First free byte in the buffer */
+       unsigned char *buf_stop_ptr; /* Last byte + 1 */
+
+       if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled) {
                DEBUG(printk("Invalid minor %d\n", dev));
                return -ENODEV;
        }
        port = &ports[dev];
 
-       DEBUGWRITE(printk("W d%d c %lu (%d/%d)\n", port->port_nbr, count, port->out_count, OUT_BUFFER_SIZE));
-       /* Space to end of buffer */
-       /*
-        * out_buffer <c1>012345<-   c    ->OUT_BUFFER_SIZE
-        *            outp^    +out_count
-                               ^free_outp
-        * out_buffer 45<-     c      ->0123OUT_BUFFER_SIZE
-        *             +out_count   outp^
-        *              free_outp
-        *
+       /* |<-         OUT_BUFFER_SIZE                          ->|
+        *           |<- out_buf_count ->|
+        *                               |<- trunc_count ->| ...->|
+        *  ______________________________________________________
+        * |  free   |   data            | free                   |
+        * |_________|___________________|________________________|
+        *           ^ rd_ptr            ^ wr_ptr
         */
+       DEBUGWRITE(printk(KERN_DEBUG "W d%d c %lu a: %p c: %p\n",
+                         port->port_nbr, count, port->active_tr_descr,
+                         port->catch_tr_descr));
 
        /* Read variables that may be updated by interrupts */
        spin_lock_irqsave(&port->lock, flags);
-       count = count > OUT_BUFFER_SIZE - port->out_count ? OUT_BUFFER_SIZE  - port->out_count : count;
-       outp = (unsigned long)port->outp;
-       free_outp = outp + port->out_count;
+       rd_ptr = port->out_rd_ptr;
+       out_buf_count = port->out_buf_count;
        spin_unlock_irqrestore(&port->lock, flags);
-       out_buffer = (unsigned long)port->out_buffer;
 
-       /* Find out where and how much to write */
-       if (free_outp >= out_buffer + OUT_BUFFER_SIZE)
-               free_outp -= OUT_BUFFER_SIZE;
-       if (free_outp >= outp)
-               c = out_buffer + OUT_BUFFER_SIZE - free_outp;
-       else
-               c = outp - free_outp;
-       if (c > count)
-               c = count;
+       /* Check if resources are available */
+       if (port->tr_running &&
+           ((port->use_dma && port->active_tr_descr == port->catch_tr_descr) ||
+            out_buf_count >= OUT_BUFFER_SIZE)) {
+               DEBUGWRITE(printk(KERN_DEBUG "sser%d full\n", dev));
+               return -EAGAIN;
+       }
+
+       buf_stop_ptr = port->out_buffer + OUT_BUFFER_SIZE;
 
-//     DEBUGWRITE(printk("w op %08lX fop %08lX c %lu\n", outp, free_outp, c));
-       if (copy_from_user((void*)free_outp, buf, c))
+       /* Determine pointer to the first free byte, before copying. */
+       wr_ptr = rd_ptr + out_buf_count;
+       if (wr_ptr >= buf_stop_ptr)
+               wr_ptr -= OUT_BUFFER_SIZE;
+
+       /* If we wrap the ring buffer, let the user space program handle it by
+        * truncating the data. This could be more elegant, small buffer
+        * fragments may occur.
+        */
+       bytes_free = OUT_BUFFER_SIZE - out_buf_count;
+       if (wr_ptr + bytes_free > buf_stop_ptr)
+               bytes_free = buf_stop_ptr - wr_ptr;
+       trunc_count = (count < bytes_free) ? count : bytes_free;
+
+       if (copy_from_user(wr_ptr, buf, trunc_count))
                return -EFAULT;
 
-       if (c != count) {
-               buf += c;
-               c1 = count - c;
-               DEBUGWRITE(printk("w2 fi %lu c %lu c1 %lu\n", free_outp-out_buffer, c, c1));
-               if (copy_from_user((void*)out_buffer, buf, c1))
-                       return -EFAULT;
-       }
-       spin_lock_irqsave(&port->lock, flags);
-       port->out_count += count;
-       spin_unlock_irqrestore(&port->lock, flags);
+       DEBUGOUTBUF(printk(KERN_DEBUG "%-4d + %-4d = %-4d     %p %p %p\n",
+                          out_buf_count, trunc_count,
+                          port->out_buf_count, port->out_buffer,
+                          wr_ptr, buf_stop_ptr));
 
        /* Make sure transmitter/receiver is running */
-       if (!port->started)
-       {
+       if (!port->started) {
                reg_sser_rw_cfg cfg = REG_RD(sser, port->regi_sser, rw_cfg);
-               reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser, rw_tr_cfg);
                reg_sser_rw_rec_cfg rec_cfg = REG_RD(sser, port->regi_sser, rw_rec_cfg);
                cfg.en = regk_sser_yes;
-               tr_cfg.tr_en = port->output;
                rec_cfg.rec_en = port->input;
                REG_WR(sser, port->regi_sser, rw_cfg, cfg);
-               REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
                REG_WR(sser, port->regi_sser, rw_rec_cfg, rec_cfg);
                port->started = 1;
        }
 
-       if (file->f_flags & O_NONBLOCK) {
-               spin_lock_irqsave(&port->lock, flags);
-               if (!port->tr_running) {
-                       if (!port->use_dma) {
-                               reg_sser_rw_intr_mask intr_mask;
-                               intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
-                               /* Start sender by writing data */
-                               send_word(port);
-                               /* and enable transmitter ready IRQ */
-                               intr_mask.trdy = 1;
-                               REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
-                       } else {
-                               start_dma(port, (unsigned char* volatile )port->outp, c);
-                       }
-               }
-               spin_unlock_irqrestore(&port->lock, flags);
-               DEBUGWRITE(printk("w d%d c %lu NB\n",
-                                 port->port_nbr, count));
-               return count;
+       /* Setup wait if blocking */
+       if (!(file->f_flags & O_NONBLOCK)) {
+               add_wait_queue(&port->out_wait_q, &wait);
+               set_current_state(TASK_INTERRUPTIBLE);
        }
 
-       /* Sleep until all sent */
-
-       add_wait_queue(&port->out_wait_q, &wait);
-       set_current_state(TASK_INTERRUPTIBLE);
        spin_lock_irqsave(&port->lock, flags);
-       if (!port->tr_running) {
-               if (!port->use_dma) {
-                       reg_sser_rw_intr_mask intr_mask;
-                       intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
-                       /* Start sender by writing data */
-                       send_word(port);
-                       /* and enable transmitter ready IRQ */
-                       intr_mask.trdy = 1;
-                       REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
-               } else {
-                       start_dma(port, port->outp, c);
-               }
+       port->out_buf_count += trunc_count;
+       if (port->use_dma) {
+               start_dma_out(port, wr_ptr, trunc_count);
+       } else if (!port->tr_running) {
+               reg_sser_rw_intr_mask intr_mask;
+               intr_mask = REG_RD(sser, port->regi_sser, rw_intr_mask);
+               /* Start sender by writing data */
+               send_word(port);
+               /* and enable transmitter ready IRQ */
+               intr_mask.trdy = 1;
+               REG_WR(sser, port->regi_sser, rw_intr_mask, intr_mask);
        }
        spin_unlock_irqrestore(&port->lock, flags);
+
+       /* Exit if non blocking */
+       if (file->f_flags & O_NONBLOCK) {
+               DEBUGWRITE(printk(KERN_DEBUG "w d%d c %lu  %08x\n",
+                                 port->port_nbr, trunc_count,
+                                 REG_RD_INT(dma, port->regi_dmaout, r_intr)));
+               return trunc_count;
+       }
+
        schedule();
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&port->out_wait_q, &wait);
+
        if (signal_pending(current))
-       {
                return -EINTR;
-       }
-       DEBUGWRITE(printk("w d%d c %lu\n", port->port_nbr, count));
-       return count;
+
+       DEBUGWRITE(printk(KERN_DEBUG "w d%d c %lu\n",
+                         port->port_nbr, trunc_count));
+       return trunc_count;
 }
 
 static ssize_t sync_serial_read(struct file * file, char * buf,
@@ -926,7 +1096,7 @@ static ssize_t sync_serial_read(struct file * file, char * buf,
        unsigned char* end;
        unsigned long flags;
 
-       if (dev < 0 || dev >= NUMBER_OF_PORTS || !ports[dev].enabled)
+       if (dev < 0 || dev >= NBR_PORTS || !ports[dev].enabled)
        {
                DEBUG(printk("Invalid minor %d\n", dev));
                return -ENODEV;
@@ -949,7 +1119,6 @@ static ssize_t sync_serial_read(struct file * file, char * buf,
                port->started = 1;
        }
 
-
        /* Calculate number of available bytes */
        /* Save pointers to avoid that they are modified by interrupt */
        spin_lock_irqsave(&port->lock, flags);
@@ -958,16 +1127,14 @@ static ssize_t sync_serial_read(struct file * file, char * buf,
        spin_unlock_irqrestore(&port->lock, flags);
        while ((start == end) && !port->full) /* No data */
        {
+               DEBUGREAD(printk(KERN_DEBUG "&"));
                if (file->f_flags & O_NONBLOCK)
-               {
                        return -EAGAIN;
-               }
 
                interruptible_sleep_on(&port->in_wait_q);
                if (signal_pending(current))
-               {
                        return -EINTR;
-               }
+
                spin_lock_irqsave(&port->lock, flags);
                start = (unsigned char*)port->readp; /* cast away volatile */
                end = (unsigned char*)port->writep;  /* cast away volatile */
@@ -1004,83 +1171,105 @@ static void send_word(sync_port* port)
        switch(tr_cfg.sample_size)
        {
         case 8:
-                port->out_count--;
-                tr_data.data = *port->outp++;
+                port->out_buf_count--;
+                tr_data.data = *port->out_rd_ptr++;
                 REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-                if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
-                        port->outp = port->out_buffer;
+                if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
+                        port->out_rd_ptr = port->out_buffer;
                 break;
         case 12:
         {
-               int data = (*port->outp++) << 8;
-               data |= *port->outp++;
-               port->out_count-=2;
+               int data = (*port->out_rd_ptr++) << 8;
+               data |= *port->out_rd_ptr++;
+               port->out_buf_count -= 2;
                tr_data.data = data;
                REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-               if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
-                       port->outp = port->out_buffer;
+               if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
+                       port->out_rd_ptr = port->out_buffer;
        }
        break;
        case 16:
-               port->out_count-=2;
-               tr_data.data = *(unsigned short *)port->outp;
+               port->out_buf_count -= 2;
+               tr_data.data = *(unsigned short *)port->out_rd_ptr;
                REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-               port->outp+=2;
-               if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
-                       port->outp = port->out_buffer;
+               port->out_rd_ptr += 2;
+               if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
+                       port->out_rd_ptr = port->out_buffer;
                break;
        case 24:
-               port->out_count-=3;
-               tr_data.data = *(unsigned short *)port->outp;
+               port->out_buf_count -= 3;
+               tr_data.data = *(unsigned short *)port->out_rd_ptr;
                REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-               port->outp+=2;
-               tr_data.data = *port->outp++;
+               port->out_rd_ptr += 2;
+               tr_data.data = *port->out_rd_ptr++;
                REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-               if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
-                       port->outp = port->out_buffer;
+               if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
+                       port->out_rd_ptr = port->out_buffer;
                break;
        case 32:
-               port->out_count-=4;
-               tr_data.data = *(unsigned short *)port->outp;
+               port->out_buf_count -= 4;
+               tr_data.data = *(unsigned short *)port->out_rd_ptr;
                REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-               port->outp+=2;
-               tr_data.data = *(unsigned short *)port->outp;
+               port->out_rd_ptr += 2;
+               tr_data.data = *(unsigned short *)port->out_rd_ptr;
                REG_WR(sser, port->regi_sser, rw_tr_data, tr_data);
-               port->outp+=2;
-               if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
-                       port->outp = port->out_buffer;
+               port->out_rd_ptr += 2;
+               if (port->out_rd_ptr >= port->out_buffer + OUT_BUFFER_SIZE)
+                       port->out_rd_ptr = port->out_buffer;
                break;
        }
 }
 
-
-static void start_dma(struct sync_port* port, const char* data, int count)
+static void start_dma_out(struct sync_port *port,
+                         const char *data, int count)
 {
-       port->tr_running = 1;
-       port->out_descr.buf = (char*)virt_to_phys((char*)data);
-       port->out_descr.after = port->out_descr.buf + count;
-       port->out_descr.eol = port->out_descr.intr = 1;
+       port->active_tr_descr->buf = (char *) virt_to_phys((char *) data);
+       port->active_tr_descr->after = port->active_tr_descr->buf + count;
+       port->active_tr_descr->intr = 1;
+
+       port->active_tr_descr->eol = 1;
+       port->prev_tr_descr->eol = 0;
+
+       DEBUGTRDMA(printk(KERN_DEBUG "Inserting eolr:%p eol@:%p\n",
+               port->prev_tr_descr, port->active_tr_descr));
+       port->prev_tr_descr = port->active_tr_descr;
+       port->active_tr_descr = phys_to_virt((int) port->active_tr_descr->next);
+
+       if (!port->tr_running) {
+               reg_sser_rw_tr_cfg tr_cfg = REG_RD(sser, port->regi_sser,
+                       rw_tr_cfg);
 
-       port->out_context.saved_data = (dma_descr_data*)virt_to_phys(&port->out_descr);
-       port->out_context.saved_data_buf = port->out_descr.buf;
+               port->out_context.next = 0;
+               port->out_context.saved_data =
+                       (dma_descr_data *)virt_to_phys(port->prev_tr_descr);
+               port->out_context.saved_data_buf = port->prev_tr_descr->buf;
+
+               DMA_START_CONTEXT(port->regi_dmaout,
+                       virt_to_phys((char *)&port->out_context));
+
+               tr_cfg.tr_en = regk_sser_yes;
+               REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
+               DEBUGTRDMA(printk(KERN_DEBUG "dma s\n"););
+       } else {
+               DMA_CONTINUE_DATA(port->regi_dmaout);
+               DEBUGTRDMA(printk(KERN_DEBUG "dma c\n"););
+       }
 
-       DMA_START_CONTEXT(port->regi_dmaout, virt_to_phys((char*)&port->out_context));
-       DEBUGTXINT(printk("dma %08lX c %d\n", (unsigned long)data, count));
+       port->tr_running = 1;
 }
 
-static void start_dma_in(sync_port* port)
+static void start_dma_in(sync_port *port)
 {
        int i;
-       char* buf;
+       char *buf;
        port->writep = port->flip;
 
-       if (port->writep > port->flip + port->in_buffer_size)
-       {
+       if (port->writep > port->flip + port->in_buffer_size) {
                panic("Offset too large in sync serial driver\n");
                return;
        }
        buf = (char*)virt_to_phys(port->in_buffer);
-       for (i = 0; i < NUM_IN_DESCR; i++) {
+       for (i = 0; i < NBR_IN_DESCR; i++) {
                port->in_descr[i].buf = buf;
                port->in_descr[i].after = buf + port->inbufchunk;
                port->in_descr[i].intr = 1;
@@ -1092,59 +1281,126 @@ static void start_dma_in(sync_port* port)
        port->in_descr[i-1].next = (dma_descr_data*)virt_to_phys(&port->in_descr[0]);
        port->in_descr[i-1].eol = regk_sser_yes;
        port->next_rx_desc = &port->in_descr[0];
-       port->prev_rx_desc = &port->in_descr[NUM_IN_DESCR - 1];
+       port->prev_rx_desc = &port->in_descr[NBR_IN_DESCR - 1];
        port->in_context.saved_data = (dma_descr_data*)virt_to_phys(&port->in_descr[0]);
        port->in_context.saved_data_buf = port->in_descr[0].buf;
        DMA_START_CONTEXT(port->regi_dmain, virt_to_phys(&port->in_context));
 }
 
 #ifdef SYNC_SER_DMA
-static irqreturn_t tr_interrupt(int irq, void *dev_id, struct pt_regs * regs)
+static irqreturn_t tr_interrupt(int irq, void *dev_id)
 {
        reg_dma_r_masked_intr masked;
        reg_dma_rw_ack_intr ack_intr = {.data = regk_dma_yes};
+       reg_dma_rw_stat stat;
        int i;
-       struct dma_descr_data *descr;
-       unsigned int sentl;
        int found = 0;
+       int stop_sser = 0;
 
-       for (i = 0; i < NUMBER_OF_PORTS; i++)
-       {
+       for (i = 0; i < NBR_PORTS; i++) {
                sync_port *port = &ports[i];
-               if (!port->enabled  || !port->use_dma )
+               if (!port->enabled  || !port->use_dma)
                        continue;
 
+               /* IRQ active for the port? */
                masked = REG_RD(dma, port->regi_dmaout, r_masked_intr);
+               if (!masked.data)
+                       continue;
 
-               if (masked.data) /* IRQ active for the port? */
-               {
-                       found = 1;
-                       /* Clear IRQ */
-                       REG_WR(dma, port->regi_dmaout, rw_ack_intr, ack_intr);
-                       descr = &port->out_descr;
-                       sentl = descr->after - descr->buf;
-                       port->out_count -= sentl;
-                       port->outp += sentl;
-                       if (port->outp >= port->out_buffer + OUT_BUFFER_SIZE)
-                               port->outp = port->out_buffer;
-                       if (port->out_count)  {
-                               int c;
-                               c = port->out_buffer + OUT_BUFFER_SIZE - port->outp;
-                               if (c > port->out_count)
-                                       c = port->out_count;
-                               DEBUGTXINT(printk("tx_int DMAWRITE %i %i\n", sentl, c));
-                               start_dma(port, port->outp, c);
-                       } else  {
-                               DEBUGTXINT(printk("tx_int DMA stop %i\n", sentl));
-                               port->tr_running = 0;
+               found = 1;
+
+               /* Check if we should stop the DMA transfer */
+               stat = REG_RD(dma, port->regi_dmaout, rw_stat);
+               if (stat.list_state == regk_dma_data_at_eol)
+                       stop_sser = 1;
+
+               /* Clear IRQ */
+               REG_WR(dma, port->regi_dmaout, rw_ack_intr, ack_intr);
+
+               if (!stop_sser) {
+                       /* The DMA has completed a descriptor, EOL was not
+                        * encountered, so step relevant descriptor and
+                        * datapointers forward. */
+                       int sent;
+                       sent = port->catch_tr_descr->after -
+                               port->catch_tr_descr->buf;
+                       DEBUGTXINT(printk(KERN_DEBUG "%-4d - %-4d = %-4d\t"
+                                         "in descr %p (ac: %p)\n",
+                                         port->out_buf_count, sent,
+                                         port->out_buf_count - sent,
+                                         port->catch_tr_descr,
+                                         port->active_tr_descr););
+                       port->out_buf_count -= sent;
+                       port->catch_tr_descr =
+                               phys_to_virt((int) port->catch_tr_descr->next);
+                       port->out_rd_ptr =
+                               phys_to_virt((int) port->catch_tr_descr->buf);
+               } else {
+                       int i, sent;
+                       /* EOL handler.
+                        * Note that if an EOL was encountered during the irq
+                        * locked section of sync_ser_write the DMA will be
+                        * restarted and the eol flag will be cleared.
+                        * The remaining descriptors will be traversed by
+                        * the descriptor interrupts as usual.
+                        */
+                       i = 0;
+                       while (!port->catch_tr_descr->eol) {
+                               sent = port->catch_tr_descr->after -
+                                       port->catch_tr_descr->buf;
+                               DEBUGOUTBUF(printk(KERN_DEBUG
+                                       "traversing descr %p -%d (%d)\n",
+                                       port->catch_tr_descr,
+                                       sent,
+                                       port->out_buf_count));
+                               port->out_buf_count -= sent;
+                               port->catch_tr_descr = phys_to_virt(
+                                       (int)port->catch_tr_descr->next);
+                               i++;
+                               if (i >= NBR_OUT_DESCR) {
+                                       /* TODO: Reset and recover */
+                                       panic("sync_serial: missing eol");
+                               }
                        }
-                       wake_up_interruptible(&port->out_wait_q); /* wake up the waiting process */
+                       sent = port->catch_tr_descr->after -
+                               port->catch_tr_descr->buf;
+                       DEBUGOUTBUF(printk(KERN_DEBUG
+                               "eol at descr %p -%d (%d)\n",
+                               port->catch_tr_descr,
+                               sent,
+                               port->out_buf_count));
+
+                       port->out_buf_count -= sent;
+
+                       /* Update read pointer to first free byte, we
+                        * may already be writing data there. */
+                       port->out_rd_ptr =
+                               phys_to_virt((int) port->catch_tr_descr->after);
+                       if (port->out_rd_ptr > port->out_buffer +
+                                       OUT_BUFFER_SIZE)
+                               port->out_rd_ptr = port->out_buffer;
+
+                       reg_sser_rw_tr_cfg tr_cfg =
+                               REG_RD(sser, port->regi_sser, rw_tr_cfg);
+                       DEBUGTXINT(printk(KERN_DEBUG
+                               "tr_int DMA stop %d, set catch @ %p\n",
+                               port->out_buf_count,
+                               port->active_tr_descr));
+                       if (port->out_buf_count != 0)
+                               printk(KERN_CRIT "sync_ser: buffer not "
+                                       "empty after eol.\n");
+                       port->catch_tr_descr = port->active_tr_descr;
+                       port->tr_running = 0;
+                       tr_cfg.tr_en = regk_sser_no;
+                       REG_WR(sser, port->regi_sser, rw_tr_cfg, tr_cfg);
                }
+               /* wake up the waiting process */
+               wake_up_interruptible(&port->out_wait_q);
        }
        return IRQ_RETVAL(found);
 } /* tr_interrupt */
 
-static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
+static irqreturn_t rx_interrupt(int irq, void *dev_id)
 {
        reg_dma_r_masked_intr masked;
        reg_dma_rw_ack_intr ack_intr = {.data = regk_dma_yes};
@@ -1152,7 +1408,7 @@ static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
        int i;
        int found = 0;
 
-       for (i = 0; i < NUMBER_OF_PORTS; i++)
+       for (i = 0; i < NBR_PORTS; i++)
        {
                sync_port *port = &ports[i];
 
@@ -1166,7 +1422,7 @@ static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
                        found = 1;
                        while (REG_RD(dma, port->regi_dmain, rw_data) !=
                               virt_to_phys(port->next_rx_desc)) {
-
+                               DEBUGRXINT(printk(KERN_DEBUG "!"));
                                if (port->writep + port->inbufchunk > port->flip + port->in_buffer_size) {
                                        int first_size = port->flip + port->in_buffer_size - port->writep;
                                        memcpy((char*)port->writep, phys_to_virt((unsigned)port->next_rx_desc->buf), first_size);
@@ -1185,11 +1441,16 @@ static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
                                  port->full = 1;
                                 }
 
-                               port->next_rx_desc->eol = 0;
-                               port->prev_rx_desc->eol = 1;
-                               port->prev_rx_desc = phys_to_virt((unsigned)port->next_rx_desc);
+                               port->next_rx_desc->eol = 1;
+                               port->prev_rx_desc->eol = 0;
+                               /* Cache bug workaround */
+                               flush_dma_descr(port->prev_rx_desc, 0);
+                               port->prev_rx_desc = port->next_rx_desc;
                                port->next_rx_desc = phys_to_virt((unsigned)port->next_rx_desc->next);
-                               wake_up_interruptible(&port->in_wait_q); /* wake up the waiting process */
+                               /* Cache bug workaround */
+                               flush_dma_descr(port->prev_rx_desc, 1);
+                               /* wake up the waiting process */
+                               wake_up_interruptible(&port->in_wait_q);
                                DMA_CONTINUE(port->regi_dmain);
                                REG_WR(dma, port->regi_dmain, rw_ack_intr, ack_intr);
 
@@ -1201,15 +1462,15 @@ static irqreturn_t rx_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 #endif /* SYNC_SER_DMA */
 
 #ifdef SYNC_SER_MANUAL
-static irqreturn_t manual_interrupt(int irq, void *dev_id, struct pt_regs * regs)
+static irqreturn_t manual_interrupt(int irq, void *dev_id)
 {
        int i;
        int found = 0;
        reg_sser_r_masked_intr masked;
 
-       for (i = 0; i < NUMBER_OF_PORTS; i++)
+       for (i = 0; i < NBR_PORTS; i++)
        {
-               sync_port* port = &ports[i];
+               sync_port *port = &ports[i];
 
                if (!port->enabled || port->use_dma)
                {
@@ -1263,7 +1524,7 @@ static irqreturn_t manual_interrupt(int irq, void *dev_id, struct pt_regs * regs
                if (masked.trdy) /* Transmitter ready? */
                {
                        found = 1;
-                       if (port->out_count > 0) /* More data to send */
+                       if (port->out_buf_count > 0) /* More data to send */
                                send_word(port);
                        else /* transmission finished */
                        {