USB: Add MUSB and TUSB support

This patch adds support for MUSB and TUSB controllers
integrated into omap2430 and davinci. It also adds support
for external tusb6010 controller.

Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 719 insertions, 0 deletions

diff --git a/drivers/usb/musb/tusb6010_omap.c b/drivers/usb/musb/tusb6010_omap.c
new file mode 100644
index 000000000000..52f7f29cebda
--- /dev/null
+++ b/drivers/usb/musb/tusb6010_omap.c
@@ -0,0 +1,719 @@
+/*
+ * TUSB6010 USB 2.0 OTG Dual Role controller OMAP DMA interface
+ *
+ * Copyright (C) 2006 Nokia Corporation
+ * Tony Lindgren <tony@atomide.com>
+ *
+ * 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/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <asm/arch/dma.h>
+#include <asm/arch/mux.h>
+
+#include "musb_core.h"
+
+#define to_chdat(c)             ((struct tusb_omap_dma_ch *)(c)->private_data)
+
+#define MAX_DMAREQ              5       /* REVISIT: Really 6, but req5 not OK */
+
+struct tusb_omap_dma_ch {
+        struct musb             *musb;
+        void __iomem            *tbase;
+        unsigned long           phys_offset;
+        int                     epnum;
+        u8                      tx;
+        struct musb_hw_ep       *hw_ep;
+
+        int                     ch;
+        s8                      dmareq;
+        s8                      sync_dev;
+
+        struct tusb_omap_dma    *tusb_dma;
+
+        void __iomem            *dma_addr;
+
+        u32                     len;
+        u16                     packet_sz;
+        u16                     transfer_packet_sz;
+        u32                     transfer_len;
+        u32                     completed_len;
+};
+
+struct tusb_omap_dma {
+        struct dma_controller           controller;
+        struct musb                     *musb;
+        void __iomem                    *tbase;
+
+        int                             ch;
+        s8                              dmareq;
+        s8                              sync_dev;
+        unsigned                        multichannel:1;
+};
+
+static int tusb_omap_dma_start(struct dma_controller *c)
+{
+        struct tusb_omap_dma    *tusb_dma;
+
+        tusb_dma = container_of(c, struct tusb_omap_dma, controller);
+
+        /* DBG(3, "ep%i ch: %i\n", chdat->epnum, chdat->ch); */
+
+        return 0;
+}
+
+static int tusb_omap_dma_stop(struct dma_controller *c)
+{
+        struct tusb_omap_dma    *tusb_dma;
+
+        tusb_dma = container_of(c, struct tusb_omap_dma, controller);
+
+        /* DBG(3, "ep%i ch: %i\n", chdat->epnum, chdat->ch); */
+
+        return 0;
+}
+
+/*
+ * Allocate dmareq0 to the current channel unless it's already taken
+ */
+static inline int tusb_omap_use_shared_dmareq(struct tusb_omap_dma_ch *chdat)
+{
+        u32             reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
+
+        if (reg != 0) {
+                DBG(3, "ep%i dmareq0 is busy for ep%i\n",
+                        chdat->epnum, reg & 0xf);
+                return -EAGAIN;
+        }
+
+        if (chdat->tx)
+                reg = (1 << 4) | chdat->epnum;
+        else
+                reg = chdat->epnum;
+
+        musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
+
+        return 0;
+}
+
+static inline void tusb_omap_free_shared_dmareq(struct tusb_omap_dma_ch *chdat)
+{
+        u32             reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
+
+        if ((reg & 0xf) != chdat->epnum) {
+                printk(KERN_ERR "ep%i trying to release dmareq0 for ep%i\n",
+                        chdat->epnum, reg & 0xf);
+                return;
+        }
+        musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, 0);
+}
+
+/*
+ * See also musb_dma_completion in plat_uds.c and musb_g_[tx|rx]() in
+ * musb_gadget.c.
+ */
+static void tusb_omap_dma_cb(int lch, u16 ch_status, void *data)
+{
+        struct dma_channel      *channel = (struct dma_channel *)data;
+        struct tusb_omap_dma_ch *chdat = to_chdat(channel);
+        struct tusb_omap_dma    *tusb_dma = chdat->tusb_dma;
+        struct musb             *musb = chdat->musb;
+        struct musb_hw_ep       *hw_ep = chdat->hw_ep;
+        void __iomem            *ep_conf = hw_ep->conf;
+        void __iomem            *mbase = musb->mregs;
+        unsigned long           remaining, flags, pio;
+        int                     ch;
+
+        spin_lock_irqsave(&musb->lock, flags);
+
+        if (tusb_dma->multichannel)
+                ch = chdat->ch;
+        else
+                ch = tusb_dma->ch;
+
+        if (ch_status != OMAP_DMA_BLOCK_IRQ)
+                printk(KERN_ERR "TUSB DMA error status: %i\n", ch_status);
+
+        DBG(3, "ep%i %s dma callback ch: %i status: %x\n",
+                chdat->epnum, chdat->tx ? "tx" : "rx",
+                ch, ch_status);
+
+        if (chdat->tx)
+                remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
+        else
+                remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
+
+        remaining = TUSB_EP_CONFIG_XFR_SIZE(remaining);
+
+        /* HW issue #10: XFR_SIZE may get corrupt on DMA (both async & sync) */
+        if (unlikely(remaining > chdat->transfer_len)) {
+                DBG(2, "Corrupt %s dma ch%i XFR_SIZE: 0x%08lx\n",
+                        chdat->tx ? "tx" : "rx", chdat->ch,
+                        remaining);
+                remaining = 0;
+        }
+
+        channel->actual_len = chdat->transfer_len - remaining;
+        pio = chdat->len - channel->actual_len;
+
+        DBG(3, "DMA remaining %lu/%u\n", remaining, chdat->transfer_len);
+
+        /* Transfer remaining 1 - 31 bytes */
+        if (pio > 0 && pio < 32) {
+                u8      *buf;
+
+                DBG(3, "Using PIO for remaining %lu bytes\n", pio);
+                buf = phys_to_virt((u32)chdat->dma_addr) + chdat->transfer_len;
+                if (chdat->tx) {
+                        dma_cache_maint(phys_to_virt((u32)chdat->dma_addr),
+                                        chdat->transfer_len, DMA_TO_DEVICE);
+                        musb_write_fifo(hw_ep, pio, buf);
+                } else {
+                        musb_read_fifo(hw_ep, pio, buf);
+                        dma_cache_maint(phys_to_virt((u32)chdat->dma_addr),
+                                        chdat->transfer_len, DMA_FROM_DEVICE);
+                }
+                channel->actual_len += pio;
+        }
+
+        if (!tusb_dma->multichannel)
+                tusb_omap_free_shared_dmareq(chdat);
+
+        channel->status = MUSB_DMA_STATUS_FREE;
+
+        /* Handle only RX callbacks here. TX callbacks must be handled based
+         * on the TUSB DMA status interrupt.
+         * REVISIT: Use both TUSB DMA status interrupt and OMAP DMA callback
+         * interrupt for RX and TX.
+         */
+        if (!chdat->tx)
+                musb_dma_completion(musb, chdat->epnum, chdat->tx);
+
+        /* We must terminate short tx transfers manually by setting TXPKTRDY.
+         * REVISIT: This same problem may occur with other MUSB dma as well.
+         * Easy to test with g_ether by pinging the MUSB board with ping -s54.
+         */
+        if ((chdat->transfer_len < chdat->packet_sz)
+                        || (chdat->transfer_len % chdat->packet_sz != 0)) {
+                u16     csr;
+
+                if (chdat->tx) {
+                        DBG(3, "terminating short tx packet\n");
+                        musb_ep_select(mbase, chdat->epnum);
+                        csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
+                        csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY
+                                | MUSB_TXCSR_P_WZC_BITS;
+                        musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
+                }
+        }
+
+        spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+static int tusb_omap_dma_program(struct dma_channel *channel, u16 packet_sz,
+                                u8 rndis_mode, dma_addr_t dma_addr, u32 len)
+{
+        struct tusb_omap_dma_ch         *chdat = to_chdat(channel);
+        struct tusb_omap_dma            *tusb_dma = chdat->tusb_dma;
+        struct musb                     *musb = chdat->musb;
+        struct musb_hw_ep               *hw_ep = chdat->hw_ep;
+        void __iomem                    *mbase = musb->mregs;
+        void __iomem                    *ep_conf = hw_ep->conf;
+        dma_addr_t                      fifo = hw_ep->fifo_sync;
+        struct omap_dma_channel_params  dma_params;
+        u32                             dma_remaining;
+        int                             src_burst, dst_burst;
+        u16                             csr;
+        int                             ch;
+        s8                              dmareq;
+        s8                              sync_dev;
+
+        if (unlikely(dma_addr & 0x1) || (len < 32) || (len > packet_sz))
+                return false;
+
+        /*
+         * HW issue #10: Async dma will eventually corrupt the XFR_SIZE
+         * register which will cause missed DMA interrupt. We could try to
+         * use a timer for the callback, but it is unsafe as the XFR_SIZE
+         * register is corrupt, and we won't know if the DMA worked.
+         */
+        if (dma_addr & 0x2)
+                return false;
+
+        /*
+         * Because of HW issue #10, it seems like mixing sync DMA and async
+         * PIO access can confuse the DMA. Make sure XFR_SIZE is reset before
+         * using the channel for DMA.
+         */
+        if (chdat->tx)
+                dma_remaining = musb_readl(ep_conf, TUSB_EP_TX_OFFSET);
+        else
+                dma_remaining = musb_readl(ep_conf, TUSB_EP_RX_OFFSET);
+
+        dma_remaining = TUSB_EP_CONFIG_XFR_SIZE(dma_remaining);
+        if (dma_remaining) {
+                DBG(2, "Busy %s dma ch%i, not using: %08x\n",
+                        chdat->tx ? "tx" : "rx", chdat->ch,
+                        dma_remaining);
+                return false;
+        }
+
+        chdat->transfer_len = len & ~0x1f;
+
+        if (len < packet_sz)
+                chdat->transfer_packet_sz = chdat->transfer_len;
+        else
+                chdat->transfer_packet_sz = packet_sz;
+
+        if (tusb_dma->multichannel) {
+                ch = chdat->ch;
+                dmareq = chdat->dmareq;
+                sync_dev = chdat->sync_dev;
+        } else {
+                if (tusb_omap_use_shared_dmareq(chdat) != 0) {
+                        DBG(3, "could not get dma for ep%i\n", chdat->epnum);
+                        return false;
+                }
+                if (tusb_dma->ch < 0) {
+                        /* REVISIT: This should get blocked earlier, happens
+                         * with MSC ErrorRecoveryTest
+                         */
+                        WARN_ON(1);
+                        return false;
+                }
+
+                ch = tusb_dma->ch;
+                dmareq = tusb_dma->dmareq;
+                sync_dev = tusb_dma->sync_dev;
+                omap_set_dma_callback(ch, tusb_omap_dma_cb, channel);
+        }
+
+        chdat->packet_sz = packet_sz;
+        chdat->len = len;
+        channel->actual_len = 0;
+        chdat->dma_addr = (void __iomem *)dma_addr;
+        channel->status = MUSB_DMA_STATUS_BUSY;
+
+        /* Since we're recycling dma areas, we need to clean or invalidate */
+        if (chdat->tx)
+                dma_cache_maint(phys_to_virt(dma_addr), len, DMA_TO_DEVICE);
+        else
+                dma_cache_maint(phys_to_virt(dma_addr), len, DMA_FROM_DEVICE);
+
+        /* Use 16-bit transfer if dma_addr is not 32-bit aligned */
+        if ((dma_addr & 0x3) == 0) {
+                dma_params.data_type = OMAP_DMA_DATA_TYPE_S32;
+                dma_params.elem_count = 8;              /* Elements in frame */
+        } else {
+                dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
+                dma_params.elem_count = 16;             /* Elements in frame */
+                fifo = hw_ep->fifo_async;
+        }
+
+        dma_params.frame_count  = chdat->transfer_len / 32; /* Burst sz frame */
+
+        DBG(3, "ep%i %s dma ch%i dma: %08x len: %u(%u) packet_sz: %i(%i)\n",
+                chdat->epnum, chdat->tx ? "tx" : "rx",
+                ch, dma_addr, chdat->transfer_len, len,
+                chdat->transfer_packet_sz, packet_sz);
+
+        /*
+         * Prepare omap DMA for transfer
+         */
+        if (chdat->tx) {
+                dma_params.src_amode    = OMAP_DMA_AMODE_POST_INC;
+                dma_params.src_start    = (unsigned long)dma_addr;
+                dma_params.src_ei       = 0;
+                dma_params.src_fi       = 0;
+
+                dma_params.dst_amode    = OMAP_DMA_AMODE_DOUBLE_IDX;
+                dma_params.dst_start    = (unsigned long)fifo;
+                dma_params.dst_ei       = 1;
+                dma_params.dst_fi       = -31;  /* Loop 32 byte window */
+
+                dma_params.trigger      = sync_dev;
+                dma_params.sync_mode    = OMAP_DMA_SYNC_FRAME;
+                dma_params.src_or_dst_synch     = 0;    /* Dest sync */
+
+                src_burst = OMAP_DMA_DATA_BURST_16;     /* 16x32 read */
+                dst_burst = OMAP_DMA_DATA_BURST_8;      /* 8x32 write */
+        } else {
+                dma_params.src_amode    = OMAP_DMA_AMODE_DOUBLE_IDX;
+                dma_params.src_start    = (unsigned long)fifo;
+                dma_params.src_ei       = 1;
+                dma_params.src_fi       = -31;  /* Loop 32 byte window */
+
+                dma_params.dst_amode    = OMAP_DMA_AMODE_POST_INC;
+                dma_params.dst_start    = (unsigned long)dma_addr;
+                dma_params.dst_ei       = 0;
+                dma_params.dst_fi       = 0;
+
+                dma_params.trigger      = sync_dev;
+                dma_params.sync_mode    = OMAP_DMA_SYNC_FRAME;
+                dma_params.src_or_dst_synch     = 1;    /* Source sync */
+
+                src_burst = OMAP_DMA_DATA_BURST_8;      /* 8x32 read */
+                dst_burst = OMAP_DMA_DATA_BURST_16;     /* 16x32 write */
+        }
+
+        DBG(3, "ep%i %s using %i-bit %s dma from 0x%08lx to 0x%08lx\n",
+                chdat->epnum, chdat->tx ? "tx" : "rx",
+                (dma_params.data_type == OMAP_DMA_DATA_TYPE_S32) ? 32 : 16,
+                ((dma_addr & 0x3) == 0) ? "sync" : "async",
+                dma_params.src_start, dma_params.dst_start);
+
+        omap_set_dma_params(ch, &dma_params);
+        omap_set_dma_src_burst_mode(ch, src_burst);
+        omap_set_dma_dest_burst_mode(ch, dst_burst);
+        omap_set_dma_write_mode(ch, OMAP_DMA_WRITE_LAST_NON_POSTED);
+
+        /*
+         * Prepare MUSB for DMA transfer
+         */
+        if (chdat->tx) {
+                musb_ep_select(mbase, chdat->epnum);
+                csr = musb_readw(hw_ep->regs, MUSB_TXCSR);
+                csr |= (MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB
+                        | MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
+                csr &= ~MUSB_TXCSR_P_UNDERRUN;
+                musb_writew(hw_ep->regs, MUSB_TXCSR, csr);
+        } else {
+                musb_ep_select(mbase, chdat->epnum);
+                csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
+                csr |= MUSB_RXCSR_DMAENAB;
+                csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAMODE);
+                musb_writew(hw_ep->regs, MUSB_RXCSR,
+                        csr | MUSB_RXCSR_P_WZC_BITS);
+        }
+
+        /*
+         * Start DMA transfer
+         */
+        omap_start_dma(ch);
+
+        if (chdat->tx) {
+                /* Send transfer_packet_sz packets at a time */
+                musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
+                        chdat->transfer_packet_sz);
+
+                musb_writel(ep_conf, TUSB_EP_TX_OFFSET,
+                        TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
+        } else {
+                /* Receive transfer_packet_sz packets at a time */
+                musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
+                        chdat->transfer_packet_sz << 16);
+
+                musb_writel(ep_conf, TUSB_EP_RX_OFFSET,
+                        TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
+        }
+
+        return true;
+}
+
+static int tusb_omap_dma_abort(struct dma_channel *channel)
+{
+        struct tusb_omap_dma_ch *chdat = to_chdat(channel);
+        struct tusb_omap_dma    *tusb_dma = chdat->tusb_dma;
+
+        if (!tusb_dma->multichannel) {
+                if (tusb_dma->ch >= 0) {
+                        omap_stop_dma(tusb_dma->ch);
+                        omap_free_dma(tusb_dma->ch);
+                        tusb_dma->ch = -1;
+                }
+
+                tusb_dma->dmareq = -1;
+                tusb_dma->sync_dev = -1;
+        }
+
+        channel->status = MUSB_DMA_STATUS_FREE;
+
+        return 0;
+}
+
+static inline int tusb_omap_dma_allocate_dmareq(struct tusb_omap_dma_ch *chdat)
+{
+        u32             reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
+        int             i, dmareq_nr = -1;
+
+        const int sync_dev[6] = {
+                OMAP24XX_DMA_EXT_DMAREQ0,
+                OMAP24XX_DMA_EXT_DMAREQ1,
+                OMAP242X_DMA_EXT_DMAREQ2,
+                OMAP242X_DMA_EXT_DMAREQ3,
+                OMAP242X_DMA_EXT_DMAREQ4,
+                OMAP242X_DMA_EXT_DMAREQ5,
+        };
+
+        for (i = 0; i < MAX_DMAREQ; i++) {
+                int cur = (reg & (0xf << (i * 5))) >> (i * 5);
+                if (cur == 0) {
+                        dmareq_nr = i;
+                        break;
+                }
+        }
+
+        if (dmareq_nr == -1)
+                return -EAGAIN;
+
+        reg |= (chdat->epnum << (dmareq_nr * 5));
+        if (chdat->tx)
+                reg |= ((1 << 4) << (dmareq_nr * 5));
+        musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
+
+        chdat->dmareq = dmareq_nr;
+        chdat->sync_dev = sync_dev[chdat->dmareq];
+
+        return 0;
+}
+
+static inline void tusb_omap_dma_free_dmareq(struct tusb_omap_dma_ch *chdat)
+{
+        u32 reg;
+
+        if (!chdat || chdat->dmareq < 0)
+                return;
+
+        reg = musb_readl(chdat->tbase, TUSB_DMA_EP_MAP);
+        reg &= ~(0x1f << (chdat->dmareq * 5));
+        musb_writel(chdat->tbase, TUSB_DMA_EP_MAP, reg);
+
+        chdat->dmareq = -1;
+        chdat->sync_dev = -1;
+}
+
+static struct dma_channel *dma_channel_pool[MAX_DMAREQ];
+
+static struct dma_channel *
+tusb_omap_dma_allocate(struct dma_controller *c,
+                struct musb_hw_ep *hw_ep,
+                u8 tx)
+{
+        int ret, i;
+        const char              *dev_name;
+        struct tusb_omap_dma    *tusb_dma;
+        struct musb             *musb;
+        void __iomem            *tbase;
+        struct dma_channel      *channel = NULL;
+        struct tusb_omap_dma_ch *chdat = NULL;
+        u32                     reg;
+
+        tusb_dma = container_of(c, struct tusb_omap_dma, controller);
+        musb = tusb_dma->musb;
+        tbase = musb->ctrl_base;
+
+        reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
+        if (tx)
+                reg &= ~(1 << hw_ep->epnum);
+        else
+                reg &= ~(1 << (hw_ep->epnum + 15));
+        musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
+
+        /* REVISIT: Why does dmareq5 not work? */
+        if (hw_ep->epnum == 0) {
+                DBG(3, "Not allowing DMA for ep0 %s\n", tx ? "tx" : "rx");
+                return NULL;
+        }
+
+        for (i = 0; i < MAX_DMAREQ; i++) {
+                struct dma_channel *ch = dma_channel_pool[i];
+                if (ch->status == MUSB_DMA_STATUS_UNKNOWN) {
+                        ch->status = MUSB_DMA_STATUS_FREE;
+                        channel = ch;
+                        chdat = ch->private_data;
+                        break;
+                }
+        }
+
+        if (!channel)
+                return NULL;
+
+        if (tx) {
+                chdat->tx = 1;
+                dev_name = "TUSB transmit";
+        } else {
+                chdat->tx = 0;
+                dev_name = "TUSB receive";
+        }
+
+        chdat->musb = tusb_dma->musb;
+        chdat->tbase = tusb_dma->tbase;
+        chdat->hw_ep = hw_ep;
+        chdat->epnum = hw_ep->epnum;
+        chdat->dmareq = -1;
+        chdat->completed_len = 0;
+        chdat->tusb_dma = tusb_dma;
+
+        channel->max_len = 0x7fffffff;
+        channel->desired_mode = 0;
+        channel->actual_len = 0;
+
+        if (tusb_dma->multichannel) {
+                ret = tusb_omap_dma_allocate_dmareq(chdat);
+                if (ret != 0)
+                        goto free_dmareq;
+
+                ret = omap_request_dma(chdat->sync_dev, dev_name,
+                                tusb_omap_dma_cb, channel, &chdat->ch);
+                if (ret != 0)
+                        goto free_dmareq;
+        } else if (tusb_dma->ch == -1) {
+                tusb_dma->dmareq = 0;
+                tusb_dma->sync_dev = OMAP24XX_DMA_EXT_DMAREQ0;
+
+                /* Callback data gets set later in the shared dmareq case */
+                ret = omap_request_dma(tusb_dma->sync_dev, "TUSB shared",
+                                tusb_omap_dma_cb, NULL, &tusb_dma->ch);
+                if (ret != 0)
+                        goto free_dmareq;
+
+                chdat->dmareq = -1;
+                chdat->ch = -1;
+        }
+
+        DBG(3, "ep%i %s dma: %s dma%i dmareq%i sync%i\n",
+                chdat->epnum,
+                chdat->tx ? "tx" : "rx",
+                chdat->ch >= 0 ? "dedicated" : "shared",
+                chdat->ch >= 0 ? chdat->ch : tusb_dma->ch,
+                chdat->dmareq >= 0 ? chdat->dmareq : tusb_dma->dmareq,
+                chdat->sync_dev >= 0 ? chdat->sync_dev : tusb_dma->sync_dev);
+
+        return channel;
+
+free_dmareq:
+        tusb_omap_dma_free_dmareq(chdat);
+
+        DBG(3, "ep%i: Could not get a DMA channel\n", chdat->epnum);
+        channel->status = MUSB_DMA_STATUS_UNKNOWN;
+
+        return NULL;
+}
+
+static void tusb_omap_dma_release(struct dma_channel *channel)
+{
+        struct tusb_omap_dma_ch *chdat = to_chdat(channel);
+        struct musb             *musb = chdat->musb;
+        void __iomem            *tbase = musb->ctrl_base;
+        u32                     reg;
+
+        DBG(3, "ep%i ch%i\n", chdat->epnum, chdat->ch);
+
+        reg = musb_readl(tbase, TUSB_DMA_INT_MASK);
+        if (chdat->tx)
+                reg |= (1 << chdat->epnum);
+        else
+                reg |= (1 << (chdat->epnum + 15));
+        musb_writel(tbase, TUSB_DMA_INT_MASK, reg);
+
+        reg = musb_readl(tbase, TUSB_DMA_INT_CLEAR);
+        if (chdat->tx)
+                reg |= (1 << chdat->epnum);
+        else
+                reg |= (1 << (chdat->epnum + 15));
+        musb_writel(tbase, TUSB_DMA_INT_CLEAR, reg);
+
+        channel->status = MUSB_DMA_STATUS_UNKNOWN;
+
+        if (chdat->ch >= 0) {
+                omap_stop_dma(chdat->ch);
+                omap_free_dma(chdat->ch);
+                chdat->ch = -1;
+        }
+
+        if (chdat->dmareq >= 0)
+                tusb_omap_dma_free_dmareq(chdat);
+
+        channel = NULL;
+}
+
+void dma_controller_destroy(struct dma_controller *c)
+{
+        struct tusb_omap_dma    *tusb_dma;
+        int                     i;
+
+        tusb_dma = container_of(c, struct tusb_omap_dma, controller);
+        for (i = 0; i < MAX_DMAREQ; i++) {
+                struct dma_channel *ch = dma_channel_pool[i];
+                if (ch) {
+                        kfree(ch->private_data);
+                        kfree(ch);
+                }
+        }
+
+        if (!tusb_dma->multichannel && tusb_dma && tusb_dma->ch >= 0)
+                omap_free_dma(tusb_dma->ch);
+
+        kfree(tusb_dma);
+}
+
+struct dma_controller *__init
+dma_controller_create(struct musb *musb, void __iomem *base)
+{
+        void __iomem            *tbase = musb->ctrl_base;
+        struct tusb_omap_dma    *tusb_dma;
+        int                     i;
+
+        /* REVISIT: Get dmareq lines used from board-*.c */
+
+        musb_writel(musb->ctrl_base, TUSB_DMA_INT_MASK, 0x7fffffff);
+        musb_writel(musb->ctrl_base, TUSB_DMA_EP_MAP, 0);
+
+        musb_writel(tbase, TUSB_DMA_REQ_CONF,
+                TUSB_DMA_REQ_CONF_BURST_SIZE(2)
+                | TUSB_DMA_REQ_CONF_DMA_REQ_EN(0x3f)
+                | TUSB_DMA_REQ_CONF_DMA_REQ_ASSER(2));
+
+        tusb_dma = kzalloc(sizeof(struct tusb_omap_dma), GFP_KERNEL);
+        if (!tusb_dma)
+                goto cleanup;
+
+        tusb_dma->musb = musb;
+        tusb_dma->tbase = musb->ctrl_base;
+
+        tusb_dma->ch = -1;
+        tusb_dma->dmareq = -1;
+        tusb_dma->sync_dev = -1;
+
+        tusb_dma->controller.start = tusb_omap_dma_start;
+        tusb_dma->controller.stop = tusb_omap_dma_stop;
+        tusb_dma->controller.channel_alloc = tusb_omap_dma_allocate;
+        tusb_dma->controller.channel_release = tusb_omap_dma_release;
+        tusb_dma->controller.channel_program = tusb_omap_dma_program;
+        tusb_dma->controller.channel_abort = tusb_omap_dma_abort;
+
+        if (tusb_get_revision(musb) >= TUSB_REV_30)
+                tusb_dma->multichannel = 1;
+
+        for (i = 0; i < MAX_DMAREQ; i++) {
+                struct dma_channel      *ch;
+                struct tusb_omap_dma_ch *chdat;
+
+                ch = kzalloc(sizeof(struct dma_channel), GFP_KERNEL);
+                if (!ch)
+                        goto cleanup;
+
+                dma_channel_pool[i] = ch;
+
+                chdat = kzalloc(sizeof(struct tusb_omap_dma_ch), GFP_KERNEL);
+                if (!chdat)
+                        goto cleanup;
+
+                ch->status = MUSB_DMA_STATUS_UNKNOWN;
+                ch->private_data = chdat;
+        }
+
+        return &tusb_dma->controller;
+
+cleanup:
+        dma_controller_destroy(&tusb_dma->controller);
+
+        return NULL;
+}