[ifxmips]:
[openwrt/svn-archive/archive.git] / target / linux / ifxmips / files / arch / mips / ifxmips / ar9 / dma-core.c
diff --git a/target/linux/ifxmips/files/arch/mips/ifxmips/ar9/dma-core.c b/target/linux/ifxmips/files/arch/mips/ifxmips/ar9/dma-core.c
new file mode 100644 (file)
index 0000000..084b283
--- /dev/null
@@ -0,0 +1,690 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/mm.h>
+#include <linux/tty.h>
+#include <linux/selection.h>
+#include <linux/kmod.h>
+#include <linux/vmalloc.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+
+#include <ifxmips.h>
+#include <ifxmips_irq.h>
+#include <ifxmips_dma.h>
+#include <ifxmips_pmu.h>
+
+/*25 descriptors for each dma channel,4096/8/20=25.xx*/
+#define IFXMIPS_DMA_DESCRIPTOR_OFFSET 25
+
+#define MAX_DMA_DEVICE_NUM  6  /*max ports connecting to dma */
+#define MAX_DMA_CHANNEL_NUM 20 /*max dma channels */
+#define DMA_INT_BUDGET      100        /*budget for interrupt handling */
+#define DMA_POLL_COUNTER    4  /*fix me, set the correct counter value here! */
+
+extern void ifxmips_mask_and_ack_irq(unsigned int irq_nr);
+extern void ifxmips_enable_irq(unsigned int irq_nr);
+extern void ifxmips_disable_irq(unsigned int irq_nr);
+
+u64 *g_desc_list;
+struct dma_device_info dma_devs[MAX_DMA_DEVICE_NUM];
+struct dma_channel_info dma_chan[MAX_DMA_CHANNEL_NUM];
+
+static const char *global_device_name[MAX_DMA_DEVICE_NUM] =
+       { "PPE", "DEU", "SPI", "SDIO", "MCTRL0", "MCTRL1" };
+
+struct dma_chan_map default_dma_map[MAX_DMA_CHANNEL_NUM] = {
+       {"PPE", IFXMIPS_DMA_RX, 0, IFXMIPS_DMA_CH0_INT, 0},
+       {"PPE", IFXMIPS_DMA_TX, 0, IFXMIPS_DMA_CH1_INT, 0},
+       {"PPE", IFXMIPS_DMA_RX, 1, IFXMIPS_DMA_CH2_INT, 1},
+       {"PPE", IFXMIPS_DMA_TX, 1, IFXMIPS_DMA_CH3_INT, 1},
+       {"PPE", IFXMIPS_DMA_RX, 2, IFXMIPS_DMA_CH4_INT, 2},
+       {"PPE", IFXMIPS_DMA_TX, 2, IFXMIPS_DMA_CH5_INT, 2},
+       {"PPE", IFXMIPS_DMA_RX, 3, IFXMIPS_DMA_CH6_INT, 3},
+       {"PPE", IFXMIPS_DMA_TX, 3, IFXMIPS_DMA_CH7_INT, 3},
+       {"DEU", IFXMIPS_DMA_RX, 0, IFXMIPS_DMA_CH8_INT, 0},
+       {"DEU", IFXMIPS_DMA_TX, 0, IFXMIPS_DMA_CH9_INT, 0},
+       {"DEU", IFXMIPS_DMA_RX, 1, IFXMIPS_DMA_CH10_INT, 1},
+       {"DEU", IFXMIPS_DMA_TX, 1, IFXMIPS_DMA_CH11_INT, 1},
+       {"SPI", IFXMIPS_DMA_RX, 0, IFXMIPS_DMA_CH12_INT, 0},
+       {"SPI", IFXMIPS_DMA_TX, 0, IFXMIPS_DMA_CH13_INT, 0},
+       {"SDIO", IFXMIPS_DMA_RX, 0, IFXMIPS_DMA_CH14_INT, 0},
+       {"SDIO", IFXMIPS_DMA_TX, 0, IFXMIPS_DMA_CH15_INT, 0},
+       {"MCTRL0", IFXMIPS_DMA_RX, 0, IFXMIPS_DMA_CH16_INT, 0},
+       {"MCTRL0", IFXMIPS_DMA_TX, 0, IFXMIPS_DMA_CH17_INT, 0},
+       {"MCTRL1", IFXMIPS_DMA_RX, 1, IFXMIPS_DMA_CH18_INT, 1},
+       {"MCTRL1", IFXMIPS_DMA_TX, 1, IFXMIPS_DMA_CH19_INT, 1}
+};
+
+struct dma_chan_map *chan_map = default_dma_map;
+volatile u32 g_ifxmips_dma_int_status;
+volatile int g_ifxmips_dma_in_process; /* 0=not in process, 1=in process */
+
+void do_dma_tasklet(unsigned long);
+DECLARE_TASKLET(dma_tasklet, do_dma_tasklet, 0);
+
+u8 *common_buffer_alloc(int len, int *byte_offset, void **opt)
+{
+       u8 *buffer = kmalloc(len * sizeof(u8), GFP_KERNEL);
+
+       *byte_offset = 0;
+
+       return buffer;
+}
+
+void common_buffer_free(u8 *dataptr, void *opt)
+{
+       kfree(dataptr);
+}
+
+void enable_ch_irq(struct dma_channel_info *pCh)
+{
+       int chan_no = (int)(pCh - dma_chan);
+       unsigned long flag;
+
+       local_irq_save(flag);
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       ifxmips_w32(0x4a, IFXMIPS_DMA_CIE);
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_IRNEN) | (1 << chan_no), IFXMIPS_DMA_IRNEN);
+       local_irq_restore(flag);
+       ifxmips_enable_irq(pCh->irq);
+}
+
+void disable_ch_irq(struct dma_channel_info *pCh)
+{
+       unsigned long flag;
+       int chan_no = (int) (pCh - dma_chan);
+
+       local_irq_save(flag);
+       g_ifxmips_dma_int_status &= ~(1 << chan_no);
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       ifxmips_w32(0, IFXMIPS_DMA_CIE);
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_IRNEN) & ~(1 << chan_no), IFXMIPS_DMA_IRNEN);
+       local_irq_restore(flag);
+       ifxmips_mask_and_ack_irq(pCh->irq);
+}
+
+void open_chan(struct dma_channel_info *pCh)
+{
+       unsigned long flag;
+       int chan_no = (int)(pCh - dma_chan);
+
+       local_irq_save(flag);
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) | 1, IFXMIPS_DMA_CCTRL);
+       if (pCh->dir == IFXMIPS_DMA_RX)
+               enable_ch_irq(pCh);
+       local_irq_restore(flag);
+}
+
+void close_chan(struct dma_channel_info *pCh)
+{
+       unsigned long flag;
+       int chan_no = (int) (pCh - dma_chan);
+
+       local_irq_save(flag);
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) & ~1, IFXMIPS_DMA_CCTRL);
+       disable_ch_irq(pCh);
+       local_irq_restore(flag);
+}
+
+void reset_chan(struct dma_channel_info *pCh)
+{
+       int chan_no = (int) (pCh - dma_chan);
+
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) | 2, IFXMIPS_DMA_CCTRL);
+}
+
+void rx_chan_intr_handler(int chan_no)
+{
+       struct dma_device_info *pDev = (struct dma_device_info *)dma_chan[chan_no].dma_dev;
+       struct dma_channel_info *pCh = &dma_chan[chan_no];
+       struct rx_desc *rx_desc_p;
+       int tmp;
+       unsigned long flag;
+
+       /*handle command complete interrupt */
+       rx_desc_p = (struct rx_desc *)pCh->desc_base + pCh->curr_desc;
+       if (rx_desc_p->status.field.OWN == CPU_OWN
+           && rx_desc_p->status.field.C
+           && rx_desc_p->status.field.data_length < 1536){
+               /* Every thing is correct, then we inform the upper layer */
+               pDev->current_rx_chan = pCh->rel_chan_no;
+               if (pDev->intr_handler)
+                       pDev->intr_handler(pDev, RCV_INT);
+               pCh->weight--;
+       } else {
+               local_irq_save(flag);
+               tmp = ifxmips_r32(IFXMIPS_DMA_CS);
+               ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+               ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CIS) | 0x7e, IFXMIPS_DMA_CIS);
+               ifxmips_w32(tmp, IFXMIPS_DMA_CS);
+               g_ifxmips_dma_int_status &= ~(1 << chan_no);
+               local_irq_restore(flag);
+               ifxmips_enable_irq(dma_chan[chan_no].irq);
+       }
+}
+
+inline void tx_chan_intr_handler(int chan_no)
+{
+       struct dma_device_info *pDev = (struct dma_device_info *)dma_chan[chan_no].dma_dev;
+       struct dma_channel_info *pCh = &dma_chan[chan_no];
+       int tmp;
+       unsigned long flag;
+
+       local_irq_save(flag);
+       tmp = ifxmips_r32(IFXMIPS_DMA_CS);
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CIS) | 0x7e, IFXMIPS_DMA_CIS);
+       ifxmips_w32(tmp, IFXMIPS_DMA_CS);
+       g_ifxmips_dma_int_status &= ~(1 << chan_no);
+       local_irq_restore(flag);
+       pDev->current_tx_chan = pCh->rel_chan_no;
+       if (pDev->intr_handler)
+               pDev->intr_handler(pDev, TRANSMIT_CPT_INT);
+}
+
+void do_dma_tasklet(unsigned long unused)
+{
+       int i;
+       int chan_no = 0;
+       int budget = DMA_INT_BUDGET;
+       int weight = 0;
+       unsigned long flag;
+
+       while (g_ifxmips_dma_int_status) {
+               if (budget-- < 0) {
+                       tasklet_schedule(&dma_tasklet);
+                       return;
+               }
+               chan_no = -1;
+               weight = 0;
+               for (i = 0; i < MAX_DMA_CHANNEL_NUM; i++) {
+                       if ((g_ifxmips_dma_int_status & (1 << i)) && dma_chan[i].weight > 0) {
+                               if (dma_chan[i].weight > weight) {
+                                       chan_no = i;
+                                       weight = dma_chan[chan_no].weight;
+                               }
+                       }
+               }
+
+               if (chan_no >= 0) {
+                       if (chan_map[chan_no].dir == IFXMIPS_DMA_RX)
+                               rx_chan_intr_handler(chan_no);
+                       else
+                               tx_chan_intr_handler(chan_no);
+               } else {
+                       for (i = 0; i < MAX_DMA_CHANNEL_NUM; i++)
+                               dma_chan[i].weight = dma_chan[i].default_weight;
+               }
+       }
+
+       local_irq_save(flag);
+       g_ifxmips_dma_in_process = 0;
+       if (g_ifxmips_dma_int_status) {
+               g_ifxmips_dma_in_process = 1;
+               tasklet_schedule(&dma_tasklet);
+       }
+       local_irq_restore(flag);
+}
+
+irqreturn_t dma_interrupt(int irq, void *dev_id)
+{
+       struct dma_channel_info *pCh;
+       int chan_no = 0;
+       int tmp;
+
+       pCh = (struct dma_channel_info *)dev_id;
+       chan_no = (int)(pCh - dma_chan);
+       if (chan_no < 0 || chan_no > 19)
+               BUG();
+
+       tmp = ifxmips_r32(IFXMIPS_DMA_IRNEN);
+       ifxmips_w32(0, IFXMIPS_DMA_IRNEN);
+       g_ifxmips_dma_int_status |= 1 << chan_no;
+       ifxmips_w32(tmp, IFXMIPS_DMA_IRNEN);
+       ifxmips_mask_and_ack_irq(irq);
+
+       if (!g_ifxmips_dma_in_process) {
+               g_ifxmips_dma_in_process = 1;
+               tasklet_schedule(&dma_tasklet);
+       }
+
+       return IRQ_HANDLED;
+}
+
+struct dma_device_info *dma_device_reserve(char *dev_name)
+{
+       int i;
+
+       for (i = 0; i < MAX_DMA_DEVICE_NUM; i++) {
+               if (strcmp(dev_name, dma_devs[i].device_name) == 0) {
+                       if (dma_devs[i].reserved)
+                               return NULL;
+                       dma_devs[i].reserved = 1;
+                       break;
+               }
+       }
+
+       return &dma_devs[i];
+}
+EXPORT_SYMBOL(dma_device_reserve);
+
+void dma_device_release(struct dma_device_info *dev)
+{
+       dev->reserved = 0;
+}
+EXPORT_SYMBOL(dma_device_release);
+
+void dma_device_register(struct dma_device_info *dev)
+{
+       int i, j;
+       int chan_no = 0;
+       u8 *buffer;
+       int byte_offset;
+       unsigned long flag;
+       struct dma_device_info *pDev;
+       struct dma_channel_info *pCh;
+       struct rx_desc *rx_desc_p;
+       struct tx_desc *tx_desc_p;
+
+       for (i = 0; i < dev->max_tx_chan_num; i++) {
+               pCh = dev->tx_chan[i];
+               if (pCh->control == IFXMIPS_DMA_CH_ON) {
+                       chan_no = (int)(pCh - dma_chan);
+                       for (j = 0; j < pCh->desc_len; j++) {
+                               tx_desc_p = (struct tx_desc *)pCh->desc_base + j;
+                               memset(tx_desc_p, 0, sizeof(struct tx_desc));
+                       }
+                       local_irq_save(flag);
+                       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+                       /* check if the descriptor length is changed */
+                       if (ifxmips_r32(IFXMIPS_DMA_CDLEN) != pCh->desc_len)
+                               ifxmips_w32(pCh->desc_len, IFXMIPS_DMA_CDLEN);
+
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) & ~1, IFXMIPS_DMA_CCTRL);
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) | 2, IFXMIPS_DMA_CCTRL);
+                       while (ifxmips_r32(IFXMIPS_DMA_CCTRL) & 2)
+                               ;
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_IRNEN) | (1 << chan_no), IFXMIPS_DMA_IRNEN);
+                       ifxmips_w32(0x30100, IFXMIPS_DMA_CCTRL); /* reset and enable channel,enable channel later */
+                       local_irq_restore(flag);
+               }
+       }
+
+       for (i = 0; i < dev->max_rx_chan_num; i++) {
+               pCh = dev->rx_chan[i];
+               if (pCh->control == IFXMIPS_DMA_CH_ON) {
+                       chan_no = (int)(pCh - dma_chan);
+
+                       for (j = 0; j < pCh->desc_len; j++) {
+                               rx_desc_p = (struct rx_desc *)pCh->desc_base + j;
+                               pDev = (struct dma_device_info *)(pCh->dma_dev);
+                               buffer = pDev->buffer_alloc(pCh->packet_size, &byte_offset, (void *)&(pCh->opt[j]));
+                               if (!buffer)
+                                       break;
+
+                               dma_cache_inv((unsigned long) buffer, pCh->packet_size);
+
+                               rx_desc_p->Data_Pointer = (u32)CPHYSADDR((u32)buffer);
+                               rx_desc_p->status.word = 0;
+                               rx_desc_p->status.field.byte_offset = byte_offset;
+                               rx_desc_p->status.field.OWN = DMA_OWN;
+                               rx_desc_p->status.field.data_length = pCh->packet_size;
+                       }
+
+                       local_irq_save(flag);
+                       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+                       /* check if the descriptor length is changed */
+                       if (ifxmips_r32(IFXMIPS_DMA_CDLEN) != pCh->desc_len)
+                               ifxmips_w32(pCh->desc_len, IFXMIPS_DMA_CDLEN);
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) & ~1, IFXMIPS_DMA_CCTRL);
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) | 2, IFXMIPS_DMA_CCTRL);
+                       while (ifxmips_r32(IFXMIPS_DMA_CCTRL) & 2)
+                               ;
+                       ifxmips_w32(0x0a, IFXMIPS_DMA_CIE); /* fix me, should enable all the interrupts here? */
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_IRNEN) | (1 << chan_no), IFXMIPS_DMA_IRNEN);
+                       ifxmips_w32(0x30000, IFXMIPS_DMA_CCTRL);
+                       local_irq_restore(flag);
+                       ifxmips_enable_irq(dma_chan[chan_no].irq);
+               }
+       }
+}
+EXPORT_SYMBOL(dma_device_register);
+
+void dma_device_unregister(struct dma_device_info *dev)
+{
+       int i, j;
+       int chan_no;
+       struct dma_channel_info *pCh;
+       struct rx_desc *rx_desc_p;
+       struct tx_desc *tx_desc_p;
+       unsigned long flag;
+
+       for (i = 0; i < dev->max_tx_chan_num; i++) {
+               pCh = dev->tx_chan[i];
+               if (pCh->control == IFXMIPS_DMA_CH_ON) {
+                       chan_no = (int)(dev->tx_chan[i] - dma_chan);
+                       local_irq_save(flag);
+                       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+                       pCh->curr_desc = 0;
+                       pCh->prev_desc = 0;
+                       pCh->control = IFXMIPS_DMA_CH_OFF;
+                       ifxmips_w32(0, IFXMIPS_DMA_CIE); /* fix me, should disable all the interrupts here? */
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_IRNEN) & ~(1 << chan_no), IFXMIPS_DMA_IRNEN); /* disable interrupts */
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) & ~1, IFXMIPS_DMA_CCTRL);
+                       while (ifxmips_r32(IFXMIPS_DMA_CCTRL) & 1)
+                               ;
+                       local_irq_restore(flag);
+
+                       for (j = 0; j < pCh->desc_len; j++) {
+                               tx_desc_p = (struct tx_desc *)pCh->desc_base + j;
+                               if ((tx_desc_p->status.field.OWN == CPU_OWN && tx_desc_p->status.field.C)
+                                               || (tx_desc_p->status.field.OWN == DMA_OWN && tx_desc_p->status.field.data_length > 0)) {
+                                       dev->buffer_free((u8 *) __va(tx_desc_p->Data_Pointer), (void *)pCh->opt[j]);
+                               }
+                               tx_desc_p->status.field.OWN = CPU_OWN;
+                               memset(tx_desc_p, 0, sizeof(struct tx_desc));
+                       }
+                       /* TODO should free buffer that is not transferred by dma */
+               }
+       }
+
+       for (i = 0; i < dev->max_rx_chan_num; i++) {
+               pCh = dev->rx_chan[i];
+               chan_no = (int)(dev->rx_chan[i] - dma_chan);
+               ifxmips_disable_irq(pCh->irq);
+
+               local_irq_save(flag);
+               g_ifxmips_dma_int_status &= ~(1 << chan_no);
+               pCh->curr_desc = 0;
+               pCh->prev_desc = 0;
+               pCh->control = IFXMIPS_DMA_CH_OFF;
+
+               ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+               ifxmips_w32(0, IFXMIPS_DMA_CIE); /* fix me, should disable all the interrupts here? */
+               ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_IRNEN) & ~(1 << chan_no), IFXMIPS_DMA_IRNEN); /* disable interrupts */
+               ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) & ~1, IFXMIPS_DMA_CCTRL);
+               while (ifxmips_r32(IFXMIPS_DMA_CCTRL) & 1)
+                       ;
+
+               local_irq_restore(flag);
+               for (j = 0; j < pCh->desc_len; j++) {
+                       rx_desc_p = (struct rx_desc *) pCh->desc_base + j;
+                       if ((rx_desc_p->status.field.OWN == CPU_OWN
+                            && rx_desc_p->status.field.C)
+                           || (rx_desc_p->status.field.OWN == DMA_OWN
+                               && rx_desc_p->status.field.data_length > 0)) {
+                               dev->buffer_free((u8 *)
+                                                __va(rx_desc_p->Data_Pointer),
+                                                (void *) pCh->opt[j]);
+                       }
+               }
+       }
+}
+EXPORT_SYMBOL(dma_device_unregister);
+
+int dma_device_read(struct dma_device_info *dma_dev, u8 **dataptr, void **opt)
+{
+       u8 *buf;
+       int len;
+       int byte_offset = 0;
+       void *p = NULL;
+       struct dma_channel_info *pCh = dma_dev->rx_chan[dma_dev->current_rx_chan];
+       struct rx_desc *rx_desc_p;
+
+       /* get the rx data first */
+       rx_desc_p = (struct rx_desc *) pCh->desc_base + pCh->curr_desc;
+       if (!(rx_desc_p->status.field.OWN == CPU_OWN && rx_desc_p->status.field.C))
+               return 0;
+
+       buf = (u8 *) __va(rx_desc_p->Data_Pointer);
+       *(u32 *)dataptr = (u32)buf;
+       len = rx_desc_p->status.field.data_length;
+
+       if (opt)
+               *(int *)opt = (int)pCh->opt[pCh->curr_desc];
+
+       /* replace with a new allocated buffer */
+       buf = dma_dev->buffer_alloc(pCh->packet_size, &byte_offset, &p);
+
+       if (buf) {
+               dma_cache_inv((unsigned long) buf, pCh->packet_size);
+               pCh->opt[pCh->curr_desc] = p;
+               wmb();
+
+               rx_desc_p->Data_Pointer = (u32) CPHYSADDR((u32) buf);
+               rx_desc_p->status.word = (DMA_OWN << 31) | ((byte_offset) << 23) | pCh->packet_size;
+               wmb();
+       } else {
+               *(u32 *) dataptr = 0;
+               if (opt)
+                       *(int *) opt = 0;
+               len = 0;
+       }
+
+       /* increase the curr_desc pointer */
+       pCh->curr_desc++;
+       if (pCh->curr_desc == pCh->desc_len)
+               pCh->curr_desc = 0;
+
+       return len;
+}
+EXPORT_SYMBOL(dma_device_read);
+
+int dma_device_write(struct dma_device_info *dma_dev, u8 *dataptr, int len, void *opt)
+{
+       unsigned long flag;
+       u32 tmp, byte_offset;
+       struct dma_channel_info *pCh;
+       int chan_no;
+       struct tx_desc *tx_desc_p;
+       local_irq_save(flag);
+
+       pCh = dma_dev->tx_chan[dma_dev->current_tx_chan];
+       chan_no = (int)(pCh - (struct dma_channel_info *) dma_chan);
+
+       tx_desc_p = (struct tx_desc *)pCh->desc_base + pCh->prev_desc;
+       while (tx_desc_p->status.field.OWN == CPU_OWN && tx_desc_p->status.field.C) {
+               dma_dev->buffer_free((u8 *) __va(tx_desc_p->Data_Pointer), pCh->opt[pCh->prev_desc]);
+               memset(tx_desc_p, 0, sizeof(struct tx_desc));
+               pCh->prev_desc = (pCh->prev_desc + 1) % (pCh->desc_len);
+               tx_desc_p = (struct tx_desc *)pCh->desc_base + pCh->prev_desc;
+       }
+       tx_desc_p = (struct tx_desc *)pCh->desc_base + pCh->curr_desc;
+       /* Check whether this descriptor is available */
+       if (tx_desc_p->status.field.OWN == DMA_OWN || tx_desc_p->status.field.C) {
+               /* if not, the tell the upper layer device */
+               dma_dev->intr_handler (dma_dev, TX_BUF_FULL_INT);
+               local_irq_restore(flag);
+               printk(KERN_INFO "%s %d: failed to write!\n", __func__, __LINE__);
+
+               return 0;
+       }
+       pCh->opt[pCh->curr_desc] = opt;
+       /* byte offset----to adjust the starting address of the data buffer, should be multiple of the burst length. */
+       byte_offset = ((u32) CPHYSADDR((u32) dataptr)) % ((dma_dev->tx_burst_len) * 4);
+       dma_cache_wback((unsigned long) dataptr, len);
+       wmb();
+       tx_desc_p->Data_Pointer = (u32) CPHYSADDR((u32) dataptr) - byte_offset;
+       wmb();
+       tx_desc_p->status.word = (DMA_OWN << 31) | DMA_DESC_SOP_SET | DMA_DESC_EOP_SET | ((byte_offset) << 23) | len;
+       wmb();
+
+       pCh->curr_desc++;
+       if (pCh->curr_desc == pCh->desc_len)
+               pCh->curr_desc = 0;
+
+       /*Check whether this descriptor is available */
+       tx_desc_p = (struct tx_desc *) pCh->desc_base + pCh->curr_desc;
+       if (tx_desc_p->status.field.OWN == DMA_OWN) {
+               /*if not , the tell the upper layer device */
+               dma_dev->intr_handler (dma_dev, TX_BUF_FULL_INT);
+       }
+
+       ifxmips_w32(chan_no, IFXMIPS_DMA_CS);
+       tmp = ifxmips_r32(IFXMIPS_DMA_CCTRL);
+
+       if (!(tmp & 1))
+               pCh->open(pCh);
+
+       local_irq_restore(flag);
+
+       return len;
+}
+EXPORT_SYMBOL(dma_device_write);
+
+int map_dma_chan(struct dma_chan_map *map)
+{
+       int i, j;
+       int result;
+
+       for (i = 0; i < MAX_DMA_DEVICE_NUM; i++)
+               strcpy(dma_devs[i].device_name, global_device_name[i]);
+
+       for (i = 0; i < MAX_DMA_CHANNEL_NUM; i++) {
+               dma_chan[i].irq = map[i].irq;
+               result = request_irq(dma_chan[i].irq, dma_interrupt, IRQF_DISABLED, map[i].dev_name, (void *)&dma_chan[i]);
+               if (result) {
+                       printk(KERN_WARNING "error, cannot get dma_irq!\n");
+                       free_irq(dma_chan[i].irq, (void *) &dma_interrupt);
+
+                       return -EFAULT;
+               }
+       }
+
+       for (i = 0; i < MAX_DMA_DEVICE_NUM; i++) {
+               dma_devs[i].num_tx_chan = 0;    /*set default tx channel number to be one */
+               dma_devs[i].num_rx_chan = 0;    /*set default rx channel number to be one */
+               dma_devs[i].max_rx_chan_num = 0;
+               dma_devs[i].max_tx_chan_num = 0;
+               dma_devs[i].buffer_alloc = &common_buffer_alloc;
+               dma_devs[i].buffer_free = &common_buffer_free;
+               dma_devs[i].intr_handler = NULL;
+               dma_devs[i].tx_burst_len = 4;
+               dma_devs[i].rx_burst_len = 4;
+               if (i == 0) {
+                       ifxmips_w32(0, IFXMIPS_DMA_PS);
+                       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_PCTRL) | ((0xf << 8) | (1 << 6)), IFXMIPS_DMA_PCTRL);       /*enable dma drop */
+               }
+
+               if (i == 1) {
+                       ifxmips_w32(1, IFXMIPS_DMA_PS);
+                       ifxmips_w32(0x14, IFXMIPS_DMA_PCTRL);   /*deu port setting */
+               }
+
+               for (j = 0; j < MAX_DMA_CHANNEL_NUM; j++) {
+                       dma_chan[j].byte_offset = 0;
+                       dma_chan[j].open = &open_chan;
+                       dma_chan[j].close = &close_chan;
+                       dma_chan[j].reset = &reset_chan;
+                       dma_chan[j].enable_irq = &enable_ch_irq;
+                       dma_chan[j].disable_irq = &disable_ch_irq;
+                       dma_chan[j].rel_chan_no = map[j].rel_chan_no;
+                       dma_chan[j].control = IFXMIPS_DMA_CH_OFF;
+                       dma_chan[j].default_weight = IFXMIPS_DMA_CH_DEFAULT_WEIGHT;
+                       dma_chan[j].weight = dma_chan[j].default_weight;
+                       dma_chan[j].curr_desc = 0;
+                       dma_chan[j].prev_desc = 0;
+               }
+
+               for (j = 0; j < MAX_DMA_CHANNEL_NUM; j++) {
+                       if (strcmp(dma_devs[i].device_name, map[j].dev_name) == 0) {
+                               if (map[j].dir == IFXMIPS_DMA_RX) {
+                                       dma_chan[j].dir = IFXMIPS_DMA_RX;
+                                       dma_devs[i].max_rx_chan_num++;
+                                       dma_devs[i].rx_chan[dma_devs[i].max_rx_chan_num - 1] = &dma_chan[j];
+                                       dma_devs[i].rx_chan[dma_devs[i].max_rx_chan_num - 1]->pri = map[j].pri;
+                                       dma_chan[j].dma_dev = (void *)&dma_devs[i];
+                               } else if (map[j].dir == IFXMIPS_DMA_TX) {
+                                       /*TX direction */
+                                       dma_chan[j].dir = IFXMIPS_DMA_TX;
+                                       dma_devs[i].max_tx_chan_num++;
+                                       dma_devs[i].tx_chan[dma_devs[i].max_tx_chan_num - 1] = &dma_chan[j];
+                                       dma_devs[i].tx_chan[dma_devs[i].max_tx_chan_num - 1]->pri = map[j].pri;
+                                       dma_chan[j].dma_dev = (void *)&dma_devs[i];
+                               } else {
+                                       printk(KERN_WARNING "WRONG DMA MAP!\n");
+                               }
+                       }
+               }
+       }
+
+       return 0;
+}
+
+void dma_chip_init(void)
+{
+       int i;
+
+       /* enable DMA from PMU */
+       ifxmips_pmu_enable(IFXMIPS_PMU_PWDCR_DMA);
+
+       /* reset DMA */
+       ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CTRL) | 1, IFXMIPS_DMA_CTRL);
+
+       /* disable all interrupts */
+       ifxmips_w32(0, IFXMIPS_DMA_IRNEN);
+
+       for (i = 0; i < MAX_DMA_CHANNEL_NUM; i++) {
+               ifxmips_w32(i, IFXMIPS_DMA_CS);
+               ifxmips_w32(0x2, IFXMIPS_DMA_CCTRL);
+               ifxmips_w32(0x80000040, IFXMIPS_DMA_CPOLL);
+               ifxmips_w32(ifxmips_r32(IFXMIPS_DMA_CCTRL) & ~0x1, IFXMIPS_DMA_CCTRL);
+       }
+}
+
+int ifxmips_dma_init(void)
+{
+       int i;
+
+       dma_chip_init();
+       if (map_dma_chan(default_dma_map))
+               BUG();
+
+       g_desc_list = (u64 *)KSEG1ADDR(__get_free_page(GFP_DMA));
+
+       if (g_desc_list == NULL) {
+               printk(KERN_WARNING "no memory for desriptor\n");
+               return -ENOMEM;
+       }
+
+       memset(g_desc_list, 0, PAGE_SIZE);
+
+       for (i = 0; i < MAX_DMA_CHANNEL_NUM; i++) {
+               dma_chan[i].desc_base = (u32)g_desc_list + i * IFXMIPS_DMA_DESCRIPTOR_OFFSET * 8;
+               dma_chan[i].curr_desc = 0;
+               dma_chan[i].desc_len = IFXMIPS_DMA_DESCRIPTOR_OFFSET;
+
+               ifxmips_w32(i, IFXMIPS_DMA_CS);
+               ifxmips_w32((u32)CPHYSADDR(dma_chan[i].desc_base), IFXMIPS_DMA_CDBA);
+               ifxmips_w32(dma_chan[i].desc_len, IFXMIPS_DMA_CDLEN);
+       }
+
+       return 0;
+}
+
+arch_initcall(ifxmips_dma_init);
+
+void dma_cleanup(void)
+{
+       int i;
+
+       free_page(KSEG0ADDR((unsigned long) g_desc_list));
+       for (i = 0; i < MAX_DMA_CHANNEL_NUM; i++)
+               free_irq(dma_chan[i].irq, (void  *)&dma_interrupt);
+}
+
+MODULE_LICENSE("GPL");