WSL2-Linux-Kernel/drivers/usb/musb/tusb6010_omap.c

720 строки
18 KiB
C

/*
* 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 <mach/dma.h>
#include <mach/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;
}