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/*
* drivers/usb/musb/ux500_dma.c
*
* U8500 and U5500 DMA support code
*
* Copyright (C) 2009 STMicroelectronics
* Copyright (C) 2011 ST-Ericsson SA
* Authors:
* Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
* Praveena Nadahally <praveen.nadahally@stericsson.com>
* Rajaram Regupathy <ragupathy.rajaram@stericsson.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/pfn.h>
#include <mach/usb.h>
#include "musb_core.h"
struct ux500_dma_channel {
struct dma_channel channel;
struct ux500_dma_controller *controller;
struct musb_hw_ep *hw_ep;
struct dma_chan *dma_chan;
unsigned int cur_len;
dma_cookie_t cookie;
u8 ch_num;
u8 is_tx;
u8 is_allocated;
};
struct ux500_dma_controller {
struct dma_controller controller;
struct ux500_dma_channel rx_channel[UX500_MUSB_DMA_NUM_RX_CHANNELS];
struct ux500_dma_channel tx_channel[UX500_MUSB_DMA_NUM_TX_CHANNELS];
u32 num_rx_channels;
u32 num_tx_channels;
void *private_data;
dma_addr_t phy_base;
};
/* Work function invoked from DMA callback to handle rx transfers. */
void ux500_dma_callback(void *private_data)
{
struct dma_channel *channel = private_data;
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
struct musb *musb = hw_ep->musb;
unsigned long flags;
dev_dbg(musb->controller, "DMA rx transfer done on hw_ep=%d\n",
hw_ep->epnum);
spin_lock_irqsave(&musb->lock, flags);
ux500_channel->channel.actual_len = ux500_channel->cur_len;
ux500_channel->channel.status = MUSB_DMA_STATUS_FREE;
musb_dma_completion(musb, hw_ep->epnum,
ux500_channel->is_tx);
spin_unlock_irqrestore(&musb->lock, flags);
}
static bool ux500_configure_channel(struct dma_channel *channel,
u16 packet_sz, u8 mode,
dma_addr_t dma_addr, u32 len)
{
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct musb_hw_ep *hw_ep = ux500_channel->hw_ep;
struct dma_chan *dma_chan = ux500_channel->dma_chan;
struct dma_async_tx_descriptor *dma_desc;
enum dma_transfer_direction direction;
struct scatterlist sg;
struct dma_slave_config slave_conf;
enum dma_slave_buswidth addr_width;
dma_addr_t usb_fifo_addr = (MUSB_FIFO_OFFSET(hw_ep->epnum) +
ux500_channel->controller->phy_base);
struct musb *musb = ux500_channel->controller->private_data;
dev_dbg(musb->controller,
"packet_sz=%d, mode=%d, dma_addr=0x%x, len=%d is_tx=%d\n",
packet_sz, mode, dma_addr, len, ux500_channel->is_tx);
ux500_channel->cur_len = len;
sg_init_table(&sg, 1);
sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_addr)), len,
offset_in_page(dma_addr));
sg_dma_address(&sg) = dma_addr;
sg_dma_len(&sg) = len;
direction = ux500_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
addr_width = (len & 0x3) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
DMA_SLAVE_BUSWIDTH_4_BYTES;
slave_conf.direction = direction;
slave_conf.src_addr = usb_fifo_addr;
slave_conf.src_addr_width = addr_width;
slave_conf.src_maxburst = 16;
slave_conf.dst_addr = usb_fifo_addr;
slave_conf.dst_addr_width = addr_width;
slave_conf.dst_maxburst = 16;
slave_conf.device_fc = false;
dma_chan->device->device_control(dma_chan, DMA_SLAVE_CONFIG,
(unsigned long) &slave_conf);
dma_desc = dma_chan->device->
device_prep_slave_sg(dma_chan, &sg, 1, direction,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!dma_desc)
return false;
dma_desc->callback = ux500_dma_callback;
dma_desc->callback_param = channel;
ux500_channel->cookie = dma_desc->tx_submit(dma_desc);
dma_async_issue_pending(dma_chan);
return true;
}
static struct dma_channel *ux500_dma_channel_allocate(struct dma_controller *c,
struct musb_hw_ep *hw_ep, u8 is_tx)
{
struct ux500_dma_controller *controller = container_of(c,
struct ux500_dma_controller, controller);
struct ux500_dma_channel *ux500_channel = NULL;
struct musb *musb = controller->private_data;
u8 ch_num = hw_ep->epnum - 1;
u32 max_ch;
/* Max 8 DMA channels (0 - 7). Each DMA channel can only be allocated
* to specified hw_ep. For example DMA channel 0 can only be allocated
* to hw_ep 1 and 9.
*/
if (ch_num > 7)
ch_num -= 8;
max_ch = is_tx ? controller->num_tx_channels :
controller->num_rx_channels;
if (ch_num >= max_ch)
return NULL;
ux500_channel = is_tx ? &(controller->tx_channel[ch_num]) :
&(controller->rx_channel[ch_num]) ;
/* Check if channel is already used. */
if (ux500_channel->is_allocated)
return NULL;
ux500_channel->hw_ep = hw_ep;
ux500_channel->is_allocated = 1;
dev_dbg(musb->controller, "hw_ep=%d, is_tx=0x%x, channel=%d\n",
hw_ep->epnum, is_tx, ch_num);
return &(ux500_channel->channel);
}
static void ux500_dma_channel_release(struct dma_channel *channel)
{
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct musb *musb = ux500_channel->controller->private_data;
dev_dbg(musb->controller, "channel=%d\n", ux500_channel->ch_num);
if (ux500_channel->is_allocated) {
ux500_channel->is_allocated = 0;
channel->status = MUSB_DMA_STATUS_FREE;
channel->actual_len = 0;
}
}
static int ux500_dma_is_compatible(struct dma_channel *channel,
u16 maxpacket, void *buf, u32 length)
{
if ((maxpacket & 0x3) ||
((int)buf & 0x3) ||
(length < 512) ||
(length & 0x3))
return false;
else
return true;
}
static int ux500_dma_channel_program(struct dma_channel *channel,
u16 packet_sz, u8 mode,
dma_addr_t dma_addr, u32 len)
{
int ret;
BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
channel->status == MUSB_DMA_STATUS_BUSY);
if (!ux500_dma_is_compatible(channel, packet_sz, (void *)dma_addr, len))
return false;
channel->status = MUSB_DMA_STATUS_BUSY;
channel->actual_len = 0;
ret = ux500_configure_channel(channel, packet_sz, mode, dma_addr, len);
if (!ret)
channel->status = MUSB_DMA_STATUS_FREE;
return ret;
}
static int ux500_dma_channel_abort(struct dma_channel *channel)
{
struct ux500_dma_channel *ux500_channel = channel->private_data;
struct ux500_dma_controller *controller = ux500_channel->controller;
struct musb *musb = controller->private_data;
void __iomem *epio = musb->endpoints[ux500_channel->hw_ep->epnum].regs;
u16 csr;
dev_dbg(musb->controller, "channel=%d, is_tx=%d\n",
ux500_channel->ch_num, ux500_channel->is_tx);
if (channel->status == MUSB_DMA_STATUS_BUSY) {
if (ux500_channel->is_tx) {
csr = musb_readw(epio, MUSB_TXCSR);
csr &= ~(MUSB_TXCSR_AUTOSET |
MUSB_TXCSR_DMAENAB |
MUSB_TXCSR_DMAMODE);
musb_writew(epio, MUSB_TXCSR, csr);
} else {
csr = musb_readw(epio, MUSB_RXCSR);
csr <
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