[ARM] 3466/1: [2/3] Support for Philips PNX4008 platform: chip support

Patch from Vitaly Wool

This patch adds basic chip support for PNX4008 ARM platform.
It's basically the same as the previous one, but with the rmk's
comments taken into account.

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: Dmitry Pervushin <dpervushin@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 1109 insertions, 0 deletions

diff --git a/arch/arm/mach-pnx4008/dma.c b/arch/arm/mach-pnx4008/dma.c
new file mode 100644
index 000000000000..981aa9dcdede
--- /dev/null
+++ b/arch/arm/mach-pnx4008/dma.c
@@ -0,0 +1,1109 @@
+/*
+ *  linux/arch/arm/mach-pnx4008/dma.c
+ *
+ *  PNX4008 DMA registration and IRQ dispatching
+ *
+ *  Author:	Vitaly Wool
+ *  Copyright:	MontaVista Software Inc. (c) 2005
+ *
+ *  Based on the code from Nicolas Pitre
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/dma-mapping.h>
+#include <linux/clk.h>
+
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/hardware.h>
+#include <asm/dma.h>
+#include <asm/dma-mapping.h>
+#include <asm/io.h>
+#include <asm/mach/dma.h>
+#include <asm/arch/clock.h>
+
+static struct dma_channel {
+	char *name;
+	void (*irq_handler) (int, int, void *, struct pt_regs *);
+	void *data;
+	struct pnx4008_dma_ll *ll;
+	u32 ll_dma;
+	void *target_addr;
+	int target_id;
+} dma_channels[MAX_DMA_CHANNELS];
+
+static struct ll_pool {
+	void *vaddr;
+	void *cur;
+	dma_addr_t dma_addr;
+	int count;
+} ll_pool;
+
+static spinlock_t ll_lock = SPIN_LOCK_UNLOCKED;
+
+struct pnx4008_dma_ll *pnx4008_alloc_ll_entry(dma_addr_t * ll_dma)
+{
+	struct pnx4008_dma_ll *ll = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ll_lock, flags);
+	if (ll_pool.count > 4) { /* can give one more */
+		ll = *(struct pnx4008_dma_ll **) ll_pool.cur;
+		*ll_dma = ll_pool.dma_addr + ((void *)ll - ll_pool.vaddr);
+		*(void **)ll_pool.cur = **(void ***)ll_pool.cur;
+		memset(ll, 0, sizeof(*ll));
+		ll_pool.count--;
+	}
+	spin_unlock_irqrestore(&ll_lock, flags);
+
+	return ll;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_alloc_ll_entry);
+
+void pnx4008_free_ll_entry(struct pnx4008_dma_ll * ll, dma_addr_t ll_dma)
+{
+	unsigned long flags;
+
+	if (ll) {
+		if ((unsigned long)((long)ll - (long)ll_pool.vaddr) > 0x4000) {
+			printk(KERN_ERR "Trying to free entry not allocated by DMA\n");
+			BUG();
+		}
+
+		if (ll->flags & DMA_BUFFER_ALLOCATED)
+			ll->free(ll->alloc_data);
+
+		spin_lock_irqsave(&ll_lock, flags);
+		*(long *)ll = *(long *)ll_pool.cur;
+		*(long *)ll_pool.cur = (long)ll;
+		ll_pool.count++;
+		spin_unlock_irqrestore(&ll_lock, flags);
+	}
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_free_ll_entry);
+
+void pnx4008_free_ll(u32 ll_dma, struct pnx4008_dma_ll * ll)
+{
+	struct pnx4008_dma_ll *ptr;
+	u32 dma;
+
+	while (ll) {
+		dma = ll->next_dma;
+		ptr = ll->next;
+		pnx4008_free_ll_entry(ll, ll_dma);
+
+		ll_dma = dma;
+		ll = ptr;
+	}
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_free_ll);
+
+static int dma_channels_requested = 0;
+
+static inline void dma_increment_usage(void)
+{
+	if (!dma_channels_requested++) {
+		struct clk *clk = clk_get(0, "dma_ck");
+		if (!IS_ERR(clk)) {
+			clk_set_rate(clk, 1);
+			clk_put(clk);
+		}
+		pnx4008_config_dma(-1, -1, 1);
+	}
+}
+static inline void dma_decrement_usage(void)
+{
+	if (!--dma_channels_requested) {
+		struct clk *clk = clk_get(0, "dma_ck");
+		if (!IS_ERR(clk)) {
+			clk_set_rate(clk, 0);
+			clk_put(clk);
+		}
+		pnx4008_config_dma(-1, -1, 0);
+
+	}
+}
+
+static spinlock_t dma_lock = SPIN_LOCK_UNLOCKED;
+
+static inline void pnx4008_dma_lock(void)
+{
+	spin_lock_irq(&dma_lock);
+}
+
+static inline void pnx4008_dma_unlock(void)
+{
+	spin_unlock_irq(&dma_lock);
+}
+
+#define VALID_CHANNEL(c)	(((c) >= 0) && ((c) < MAX_DMA_CHANNELS))
+
+int pnx4008_request_channel(char *name, int ch,
+			    void (*irq_handler) (int, int, void *,
+						 struct pt_regs *), void *data)
+{
+	int i, found = 0;
+
+	/* basic sanity checks */
+	if (!name || (ch != -1 && !VALID_CHANNEL(ch)))
+		return -EINVAL;
+
+	pnx4008_dma_lock();
+
+	/* try grabbing a DMA channel with the requested priority */
+	for (i = MAX_DMA_CHANNELS - 1; i >= 0; i--) {
+		if (!dma_channels[i].name && (ch == -1 || ch == i)) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (found) {
+		dma_increment_usage();
+		dma_channels[i].name = name;
+		dma_channels[i].irq_handler = irq_handler;
+		dma_channels[i].data = data;
+		dma_channels[i].ll = NULL;
+		dma_channels[i].ll_dma = 0;
+	} else {
+		printk(KERN_WARNING "No more available DMA channels for %s\n",
+		       name);
+		i = -ENODEV;
+	}
+
+	pnx4008_dma_unlock();
+	return i;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_request_channel);
+
+void pnx4008_free_channel(int ch)
+{
+	if (!dma_channels[ch].name) {
+		printk(KERN_CRIT
+		       "%s: trying to free channel %d which is already freed\n",
+		       __FUNCTION__, ch);
+		return;
+	}
+
+	pnx4008_dma_lock();
+	pnx4008_free_ll(dma_channels[ch].ll_dma, dma_channels[ch].ll);
+	dma_channels[ch].ll = NULL;
+	dma_decrement_usage();
+
+	dma_channels[ch].name = NULL;
+	pnx4008_dma_unlock();
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_free_channel);
+
+int pnx4008_config_dma(int ahb_m1_be, int ahb_m2_be, int enable)
+{
+	unsigned long dma_cfg = __raw_readl(DMAC_CONFIG);
+
+	switch (ahb_m1_be) {
+	case 0:
+		dma_cfg &= ~(1 << 1);
+		break;
+	case 1:
+		dma_cfg |= (1 << 1);
+		break;
+	default:
+		break;
+	}
+
+	switch (ahb_m2_be) {
+	case 0:
+		dma_cfg &= ~(1 << 2);
+		break;
+	case 1:
+		dma_cfg |= (1 << 2);
+		break;
+	default:
+		break;
+	}
+
+	switch (enable) {
+	case 0:
+		dma_cfg &= ~(1 << 0);
+		break;
+	case 1:
+		dma_cfg |= (1 << 0);
+		break;
+	default:
+		break;
+	}
+
+	pnx4008_dma_lock();
+	__raw_writel(dma_cfg, DMAC_CONFIG);
+	pnx4008_dma_unlock();
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_config_dma);
+
+int pnx4008_dma_pack_control(const struct pnx4008_dma_ch_ctrl * ch_ctrl,
+			     unsigned long *ctrl)
+{
+	int i = 0, dbsize, sbsize, err = 0;
+
+	if (!ctrl || !ch_ctrl) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	*ctrl = 0;
+
+	switch (ch_ctrl->tc_mask) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 31);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+
+	switch (ch_ctrl->cacheable) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 30);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->bufferable) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 29);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->priv_mode) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 28);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->di) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 27);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->si) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 26);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->dest_ahb1) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 25);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->src_ahb1) {
+	case 0:
+		break;
+	case 1:
+		*ctrl |= (1 << 24);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->dwidth) {
+	case WIDTH_BYTE:
+		*ctrl &= ~(7 << 21);
+		break;
+	case WIDTH_HWORD:
+		*ctrl &= ~(7 << 21);
+		*ctrl |= (1 << 21);
+		break;
+	case WIDTH_WORD:
+		*ctrl &= ~(7 << 21);
+		*ctrl |= (2 << 21);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_ctrl->swidth) {
+	case WIDTH_BYTE:
+		*ctrl &= ~(7 << 18);
+		break;
+	case WIDTH_HWORD:
+		*ctrl &= ~(7 << 18);
+		*ctrl |= (1 << 18);
+		break;
+	case WIDTH_WORD:
+		*ctrl &= ~(7 << 18);
+		*ctrl |= (2 << 18);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	dbsize = ch_ctrl->dbsize;
+	while (!(dbsize & 1)) {
+		i++;
+		dbsize >>= 1;
+	}
+	if (ch_ctrl->dbsize != 1 || i > 8 || i == 1) {
+		err = -EINVAL;
+		goto out;
+	} else if (i > 1)
+		i--;
+	*ctrl &= ~(7 << 15);
+	*ctrl |= (i << 15);
+
+	sbsize = ch_ctrl->sbsize;
+	while (!(sbsize & 1)) {
+		i++;
+		sbsize >>= 1;
+	}
+	if (ch_ctrl->sbsize != 1 || i > 8 || i == 1) {
+		err = -EINVAL;
+		goto out;
+	} else if (i > 1)
+		i--;
+	*ctrl &= ~(7 << 12);
+	*ctrl |= (i << 12);
+
+	if (ch_ctrl->tr_size > 0x7ff) {
+		err = -E2BIG;
+		goto out;
+	}
+	*ctrl &= ~0x7ff;
+	*ctrl |= ch_ctrl->tr_size & 0x7ff;
+
+out:
+	return err;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_pack_control);
+
+int pnx4008_dma_parse_control(unsigned long ctrl,
+			      struct pnx4008_dma_ch_ctrl * ch_ctrl)
+{
+	int err = 0;
+
+	if (!ch_ctrl) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	ch_ctrl->tr_size = ctrl & 0x7ff;
+	ctrl >>= 12;
+
+	ch_ctrl->sbsize = 1 << (ctrl & 7);
+	if (ch_ctrl->sbsize > 1)
+		ch_ctrl->sbsize <<= 1;
+	ctrl >>= 3;
+
+	ch_ctrl->dbsize = 1 << (ctrl & 7);
+	if (ch_ctrl->dbsize > 1)
+		ch_ctrl->dbsize <<= 1;
+	ctrl >>= 3;
+
+	switch (ctrl & 7) {
+	case 0:
+		ch_ctrl->swidth = WIDTH_BYTE;
+		break;
+	case 1:
+		ch_ctrl->swidth = WIDTH_HWORD;
+		break;
+	case 2:
+		ch_ctrl->swidth = WIDTH_WORD;
+		break;
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	ctrl >>= 3;
+
+	switch (ctrl & 7) {
+	case 0:
+		ch_ctrl->dwidth = WIDTH_BYTE;
+		break;
+	case 1:
+		ch_ctrl->dwidth = WIDTH_HWORD;
+		break;
+	case 2:
+		ch_ctrl->dwidth = WIDTH_WORD;
+		break;
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	ctrl >>= 3;
+
+	ch_ctrl->src_ahb1 = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->dest_ahb1 = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->si = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->di = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->priv_mode = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->bufferable = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->cacheable = ctrl & 1;
+	ctrl >>= 1;
+
+	ch_ctrl->tc_mask = ctrl & 1;
+
+out:
+	return err;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_parse_control);
+
+int pnx4008_dma_pack_config(const struct pnx4008_dma_ch_config * ch_cfg,
+			    unsigned long *cfg)
+{
+	int err = 0;
+
+	if (!cfg || !ch_cfg) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	*cfg = 0;
+
+	switch (ch_cfg->halt) {
+	case 0:
+		break;
+	case 1:
+		*cfg |= (1 << 18);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_cfg->active) {
+	case 0:
+		break;
+	case 1:
+		*cfg |= (1 << 17);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_cfg->lock) {
+	case 0:
+		break;
+	case 1:
+		*cfg |= (1 << 16);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_cfg->itc) {
+	case 0:
+		break;
+	case 1:
+		*cfg |= (1 << 15);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_cfg->ie) {
+	case 0:
+		break;
+	case 1:
+		*cfg |= (1 << 14);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	switch (ch_cfg->flow_cntrl) {
+	case FC_MEM2MEM_DMA:
+		*cfg &= ~(7 << 11);
+		break;
+	case FC_MEM2PER_DMA:
+		*cfg &= ~(7 << 11);
+		*cfg |= (1 << 11);
+		break;
+	case FC_PER2MEM_DMA:
+		*cfg &= ~(7 << 11);
+		*cfg |= (2 << 11);
+		break;
+	case FC_PER2PER_DMA:
+		*cfg &= ~(7 << 11);
+		*cfg |= (3 << 11);
+		break;
+	case FC_PER2PER_DPER:
+		*cfg &= ~(7 << 11);
+		*cfg |= (4 << 11);
+		break;
+	case FC_MEM2PER_PER:
+		*cfg &= ~(7 << 11);
+		*cfg |= (5 << 11);
+		break;
+	case FC_PER2MEM_PER:
+		*cfg &= ~(7 << 11);
+		*cfg |= (6 << 11);
+		break;
+	case FC_PER2PER_SPER:
+		*cfg |= (7 << 11);
+		break;
+
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+	*cfg &= ~(0x1f << 6);
+	*cfg |= ((ch_cfg->dest_per & 0x1f) << 6);
+
+	*cfg &= ~(0x1f << 1);
+	*cfg |= ((ch_cfg->src_per & 0x1f) << 1);
+
+out:
+	return err;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_pack_config);
+
+int pnx4008_dma_parse_config(unsigned long cfg,
+			     struct pnx4008_dma_ch_config * ch_cfg)
+{
+	int err = 0;
+
+	if (!ch_cfg) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	cfg >>= 1;
+
+	ch_cfg->src_per = cfg & 0x1f;
+	cfg >>= 5;
+
+	ch_cfg->dest_per = cfg & 0x1f;
+	cfg >>= 5;
+
+	switch (cfg & 7) {
+	case 0:
+		ch_cfg->flow_cntrl = FC_MEM2MEM_DMA;
+		break;
+	case 1:
+		ch_cfg->flow_cntrl = FC_MEM2PER_DMA;
+		break;
+	case 2:
+		ch_cfg->flow_cntrl = FC_PER2MEM_DMA;
+		break;
+	case 3:
+		ch_cfg->flow_cntrl = FC_PER2PER_DMA;
+		break;
+	case 4:
+		ch_cfg->flow_cntrl = FC_PER2PER_DPER;
+		break;
+	case 5:
+		ch_cfg->flow_cntrl = FC_MEM2PER_PER;
+		break;
+	case 6:
+		ch_cfg->flow_cntrl = FC_PER2MEM_PER;
+		break;
+	case 7:
+		ch_cfg->flow_cntrl = FC_PER2PER_SPER;
+	}
+	cfg >>= 3;
+
+	ch_cfg->ie = cfg & 1;
+	cfg >>= 1;
+
+	ch_cfg->itc = cfg & 1;
+	cfg >>= 1;
+
+	ch_cfg->lock = cfg & 1;
+	cfg >>= 1;
+
+	ch_cfg->active = cfg & 1;
+	cfg >>= 1;
+
+	ch_cfg->halt = cfg & 1;
+
+out:
+	return err;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_parse_config);
+
+void pnx4008_dma_split_head_entry(struct pnx4008_dma_config * config,
+				  struct pnx4008_dma_ch_ctrl * ctrl)
+{
+	int new_len = ctrl->tr_size, num_entries = 0;
+	int old_len = new_len;
+	int src_width, dest_width, count = 1;
+
+	switch (ctrl->swidth) {
+	case WIDTH_BYTE:
+		src_width = 1;
+		break;
+	case WIDTH_HWORD:
+		src_width = 2;
+		break;
+	case WIDTH_WORD:
+		src_width = 4;
+		break;
+	default:
+		return;
+	}
+
+	switch (ctrl->dwidth) {
+	case WIDTH_BYTE:
+		dest_width = 1;
+		break;
+	case WIDTH_HWORD:
+		dest_width = 2;
+		break;
+	case WIDTH_WORD:
+		dest_width = 4;
+		break;
+	default:
+		return;
+	}
+
+	while (new_len > 0x7FF) {
+		num_entries++;
+		new_len = (ctrl->tr_size + num_entries) / (num_entries + 1);
+	}
+	if (num_entries != 0) {
+		struct pnx4008_dma_ll *ll = NULL;
+		config->ch_ctrl &= ~0x7ff;
+		config->ch_ctrl |= new_len;
+		if (!config->is_ll) {
+			config->is_ll = 1;
+			while (num_entries) {
+				if (!ll) {
+					config->ll =
+					    pnx4008_alloc_ll_entry(&config->
+								   ll_dma);
+					ll = config->ll;
+				} else {
+					ll->next =
+					    pnx4008_alloc_ll_entry(&ll->
+								   next_dma);
+					ll = ll->next;
+				}
+
+				if (ctrl->si)
+					ll->src_addr =
+					    config->src_addr +
+					    src_width * new_len * count;
+				else
+					ll->src_addr = config->src_addr;
+				if (ctrl->di)
+					ll->dest_addr =
+					    config->dest_addr +
+					    dest_width * new_len * count;
+				else
+					ll->dest_addr = config->dest_addr;
+				ll->ch_ctrl = config->ch_ctrl & 0x7fffffff;
+				ll->next_dma = 0;
+				ll->next = NULL;
+				num_entries--;
+				count++;
+			}
+		} else {
+			struct pnx4008_dma_ll *ll_old = config->ll;
+			unsigned long ll_dma_old = config->ll_dma;
+			while (num_entries) {
+				if (!ll) {
+					config->ll =
+					    pnx4008_alloc_ll_entry(&config->
+								   ll_dma);
+					ll = config->ll;
+				} else {
+					ll->next =
+					    pnx4008_alloc_ll_entry(&ll->
+								   next_dma);
+					ll = ll->next;
+				}
+
+				if (ctrl->si)
+					ll->src_addr =
+					    config->src_addr +
+					    src_width * new_len * count;
+				else
+					ll->src_addr = config->src_addr;
+				if (ctrl->di)
+					ll->dest_addr =
+					    config->dest_addr +
+					    dest_width * new_len * count;
+				else
+					ll->dest_addr = config->dest_addr;
+				ll->ch_ctrl = config->ch_ctrl & 0x7fffffff;
+				ll->next_dma = 0;
+				ll->next = NULL;
+				num_entries--;
+				count++;
+			}
+			ll->next_dma = ll_dma_old;
+			ll->next = ll_old;
+		}
+		/* adjust last length/tc */
+		ll->ch_ctrl = config->ch_ctrl & (~0x7ff);
+		ll->ch_ctrl |= old_len - new_len * (count - 1);
+		config->ch_ctrl &= 0x7fffffff;
+	}
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_split_head_entry);
+
+void pnx4008_dma_split_ll_entry(struct pnx4008_dma_ll * cur_ll,
+				struct pnx4008_dma_ch_ctrl * ctrl)
+{
+	int new_len = ctrl->tr_size, num_entries = 0;
+	int old_len = new_len;
+	int src_width, dest_width, count = 1;
+
+	switch (ctrl->swidth) {
+	case WIDTH_BYTE:
+		src_width = 1;
+		break;
+	case WIDTH_HWORD:
+		src_width = 2;
+		break;
+	case WIDTH_WORD:
+		src_width = 4;
+		break;
+	default:
+		return;
+	}
+
+	switch (ctrl->dwidth) {
+	case WIDTH_BYTE:
+		dest_width = 1;
+		break;
+	case WIDTH_HWORD:
+		dest_width = 2;
+		break;
+	case WIDTH_WORD:
+		dest_width = 4;
+		break;
+	default:
+		return;
+	}
+
+	while (new_len > 0x7FF) {
+		num_entries++;
+		new_len = (ctrl->tr_size + num_entries) / (num_entries + 1);
+	}
+	if (num_entries != 0) {
+		struct pnx4008_dma_ll *ll = NULL;
+		cur_ll->ch_ctrl &= ~0x7ff;
+		cur_ll->ch_ctrl |= new_len;
+		if (!cur_ll->next) {
+			while (num_entries) {
+				if (!ll) {
+					cur_ll->next =
+					    pnx4008_alloc_ll_entry(&cur_ll->
+								   next_dma);
+					ll = cur_ll->next;
+				} else {
+					ll->next =
+					    pnx4008_alloc_ll_entry(&ll->
+								   next_dma);
+					ll = ll->next;
+				}
+
+				if (ctrl->si)
+					ll->src_addr =
+					    cur_ll->src_addr +
+					    src_width * new_len * count;
+				else
+					ll->src_addr = cur_ll->src_addr;
+				if (ctrl->di)
+					ll->dest_addr =
+					    cur_ll->dest_addr +
+					    dest_width * new_len * count;
+				else
+					ll->dest_addr = cur_ll->dest_addr;
+				ll->ch_ctrl = cur_ll->ch_ctrl & 0x7fffffff;
+				ll->next_dma = 0;
+				ll->next = NULL;
+				num_entries--;
+				count++;
+			}
+		} else {
+			struct pnx4008_dma_ll *ll_old = cur_ll->next;
+			unsigned long ll_dma_old = cur_ll->next_dma;
+			while (num_entries) {
+				if (!ll) {
+					cur_ll->next =
+					    pnx4008_alloc_ll_entry(&cur_ll->
+								   next_dma);
+					ll = cur_ll->next;
+				} else {
+					ll->next =
+					    pnx4008_alloc_ll_entry(&ll->
+								   next_dma);
+					ll = ll->next;
+				}
+
+				if (ctrl->si)
+					ll->src_addr =
+					    cur_ll->src_addr +
+					    src_width * new_len * count;
+				else
+					ll->src_addr = cur_ll->src_addr;
+				if (ctrl->di)
+					ll->dest_addr =
+					    cur_ll->dest_addr +
+					    dest_width * new_len * count;
+				else
+					ll->dest_addr = cur_ll->dest_addr;
+				ll->ch_ctrl = cur_ll->ch_ctrl & 0x7fffffff;
+				ll->next_dma = 0;
+				ll->next = NULL;
+				num_entries--;
+				count++;
+			}
+
+			ll->next_dma = ll_dma_old;
+			ll->next = ll_old;
+		}
+		/* adjust last length/tc */
+		ll->ch_ctrl = cur_ll->ch_ctrl & (~0x7ff);
+		ll->ch_ctrl |= old_len - new_len * (count - 1);
+		cur_ll->ch_ctrl &= 0x7fffffff;
+	}
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_split_ll_entry);
+
+int pnx4008_config_channel(int ch, struct pnx4008_dma_config * config)
+{
+	if (!VALID_CHANNEL(ch) || !dma_channels[ch].name)
+		return -EINVAL;
+
+	pnx4008_dma_lock();
+	__raw_writel(config->src_addr, DMAC_Cx_SRC_ADDR(ch));
+	__raw_writel(config->dest_addr, DMAC_Cx_DEST_ADDR(ch));
+
+	if (config->is_ll)
+		__raw_writel(config->ll_dma, DMAC_Cx_LLI(ch));
+	else
+		__raw_writel(0, DMAC_Cx_LLI(ch));
+
+	__raw_writel(config->ch_ctrl, DMAC_Cx_CONTROL(ch));
+	__raw_writel(config->ch_cfg, DMAC_Cx_CONFIG(ch));
+	pnx4008_dma_unlock();
+
+	return 0;
+
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_config_channel);
+
+int pnx4008_channel_get_config(int ch, struct pnx4008_dma_config * config)
+{
+	if (!VALID_CHANNEL(ch) || !dma_channels[ch].name || !config)
+		return -EINVAL;
+
+	pnx4008_dma_lock();
+	config->ch_cfg = __raw_readl(DMAC_Cx_CONFIG(ch));
+	config->ch_ctrl = __raw_readl(DMAC_Cx_CONTROL(ch));
+
+	config->ll_dma = __raw_readl(DMAC_Cx_LLI(ch));
+	config->is_ll = config->ll_dma ? 1 : 0;
+
+	config->src_addr = __raw_readl(DMAC_Cx_SRC_ADDR(ch));
+	config->dest_addr = __raw_readl(DMAC_Cx_DEST_ADDR(ch));
+	pnx4008_dma_unlock();
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_channel_get_config);
+
+int pnx4008_dma_ch_enable(int ch)
+{
+	unsigned long ch_cfg;
+
+	if (!VALID_CHANNEL(ch) || !dma_channels[ch].name)
+		return -EINVAL;
+
+	pnx4008_dma_lock();
+	ch_cfg = __raw_readl(DMAC_Cx_CONFIG(ch));
+	ch_cfg |= 1;
+	__raw_writel(ch_cfg, DMAC_Cx_CONFIG(ch));
+	pnx4008_dma_unlock();
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_ch_enable);
+
+int pnx4008_dma_ch_disable(int ch)
+{
+	unsigned long ch_cfg;
+
+	if (!VALID_CHANNEL(ch) || !dma_channels[ch].name)
+		return -EINVAL;
+
+	pnx4008_dma_lock();
+	ch_cfg = __raw_readl(DMAC_Cx_CONFIG(ch));
+	ch_cfg &= ~1;
+	__raw_writel(ch_cfg, DMAC_Cx_CONFIG(ch));
+	pnx4008_dma_unlock();
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_ch_disable);
+
+int pnx4008_dma_ch_enabled(int ch)
+{
+	unsigned long ch_cfg;
+
+	if (!VALID_CHANNEL(ch) || !dma_channels[ch].name)
+		return -EINVAL;
+
+	pnx4008_dma_lock();
+	ch_cfg = __raw_readl(DMAC_Cx_CONFIG(ch));
+	pnx4008_dma_unlock();
+
+	return ch_cfg & 1;
+}
+
+EXPORT_SYMBOL_GPL(pnx4008_dma_ch_enabled);
+
+static irqreturn_t dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
+{
+	int i;
+	unsigned long dint = __raw_readl(DMAC_INT_STAT);
+	unsigned long tcint = __raw_readl(DMAC_INT_TC_STAT);
+	unsigned long eint = __raw_readl(DMAC_INT_ERR_STAT);
+	unsigned long i_bit;
+
+	for (i = MAX_DMA_CHANNELS - 1; i >= 0; i--) {
+		i_bit = 1 << i;
+		if (dint & i_bit) {
+			struct dma_channel *channel = &dma_channels[i];
+
+			if (channel->name && channel->irq_handler) {
+				int cause = 0;
+
+				if (eint & i_bit)
+					cause |= DMA_ERR_INT;
+				if (tcint & i_bit)
+					cause |= DMA_TC_INT;
+				channel->irq_handler(i, cause, channel->data,
+						     regs);
+			} else {
+				/*
+				 * IRQ for an unregistered DMA channel
+				 */
+				printk(KERN_WARNING
+				       "spurious IRQ for DMA channel %d\n", i);
+			}
+			if (tcint & i_bit)
+				__raw_writel(i_bit, DMAC_INT_TC_CLEAR);
+			if (eint & i_bit)
+				__raw_writel(i_bit, DMAC_INT_ERR_CLEAR);
+		}
+	}
+	return IRQ_HANDLED;
+}
+
+static int __init pnx4008_dma_init(void)
+{
+	int ret, i;
+
+	ret = request_irq(DMA_INT, dma_irq_handler, 0, "DMA", NULL);
+	if (ret) {
+		printk(KERN_CRIT "Wow!  Can't register IRQ for DMA\n");
+		goto out;
+	}
+
+	ll_pool.count = 0x4000 / sizeof(struct pnx4008_dma_ll);
+	ll_pool.cur = ll_pool.vaddr =
+	    dma_alloc_coherent(NULL, ll_pool.count * sizeof(struct pnx4008_dma_ll),
+			       &ll_pool.dma_addr, GFP_KERNEL);
+
+	if (!ll_pool.vaddr) {
+		ret = -ENOMEM;
+		free_irq(DMA_INT, NULL);
+		goto out;
+	}
+
+	for (i = 0; i < ll_pool.count - 1; i++) {
+		void **addr = ll_pool.vaddr + i * sizeof(struct pnx4008_dma_ll);
+		*addr = (void *)addr + sizeof(struct pnx4008_dma_ll);
+	}
+	*(long *)(ll_pool.vaddr +
+		  (ll_pool.count - 1) * sizeof(struct pnx4008_dma_ll)) =
+	    (long)ll_pool.vaddr;
+
+	__raw_writel(1, DMAC_CONFIG);
+
+out:
+	return ret;
+}
+arch_initcall(pnx4008_dma_init);