/* * MUSB OTG driver - support for Mentor's DMA controller * * Copyright 2005 Mentor Graphics Corporation * Copyright (C) 2005-2007 by Texas Instruments * * 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. * * 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, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include <linux/device.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/slab.h> #include "musb_core.h" #include "musbhsdma.h" static int dma_controller_start(struct dma_controller *c) { /* nothing to do */ return 0; } static void dma_channel_release(struct dma_channel *channel); static int dma_controller_stop(struct dma_controller *c) { struct musb_dma_controller *controller = container_of(c, struct musb_dma_controller, controller); struct musb *musb = controller->private_data; struct dma_channel *channel; u8 bit; if (controller->used_channels != 0) { dev_err(musb->controller, "Stopping DMA controller while channel active\n"); for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) { if (controller->used_channels & (1 << bit)) { channel = &controller->channel[bit].channel; dma_channel_release(channel); if (!controller->used_channels) break; } } } return 0; } static struct dma_channel *dma_channel_allocate(struct dma_controller *c, struct musb_hw_ep *hw_ep, u8 transmit) { struct musb_dma_controller *controller = container_of(c, struct musb_dma_controller, controller); struct musb_dma_channel *musb_channel = NULL; struct dma_channel *channel = NULL; u8 bit; for (bit = 0; bit < MUSB_HSDMA_CHANNELS; bit++) { if (!(controller->used_channels & (1 << bit))) { controller->used_channels |= (1 << bit); musb_channel = &(controller->channel[bit]); musb_channel->controller = controller; musb_channel->idx = bit; musb_channel->epnum = hw_ep->epnum; musb_channel->transmit = transmit; channel = &(musb_channel->channel); channel->private_data = musb_channel; channel->status = MUSB_DMA_STATUS_FREE; channel->max_len = 0x10000; /* Tx => mode 1; Rx => mode 0 */ channel->desired_mode = transmit; channel->actual_len = 0; break; } } return channel; } static void dma_channel_release(struct dma_channel *channel) { struct musb_dma_channel *musb_channel = channel->private_data; channel->actual_len = 0; musb_channel->start_addr = 0; musb_channel->len = 0; musb_channel->controller->used_channels &= ~(1 << musb_channel->idx); channel->status = MUSB_DMA_STATUS_UNKNOWN; } static void configure_channel(struct dma_channel *channel, u16 packet_sz, u8 mode, dma_addr_t dma_addr, u32 len) { struct musb_dma_channel *musb_channel = channel->private_data; struct musb_dma_controller *controller = musb_channel->controller; void __iomem *mbase = controller->base; u8 bchannel = musb_channel->idx; u16 csr = 0; DBG(4, "%p, pkt_sz %d, addr 0x%x, len %d, mode %d\n", channel, packet_sz, dma_addr, len, mode); if (mode) { csr |= 1 << MUSB_HSDMA_MODE1_SHIFT; BUG_ON(len < packet_sz); } csr |= MUSB_HSDMA_BURSTMODE_INCR16 << MUSB_HSDMA_BURSTMODE_SHIFT; csr |= (musb_channel->epnum << MUSB_HSDMA_ENDPOINT_SHIFT) | (1 << MUSB_HSDMA_ENABLE_SHIFT) | (1 << MUSB_HSDMA_IRQENABLE_SHIFT) | (musb_channel->transmit ? (1 << MUSB_HSDMA_TRANSMIT_SHIFT) : 0); /* address/count */ musb_write_hsdma_addr(mbase, bchannel, dma_addr); musb_write_hsdma_count(mbase, bchannel, len); /* control (this should start things) */ musb_writew(mbase, MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL), csr); } static int dma_channel_program(struct dma_channel *channel, u16 packet_sz, u8 mode, dma_addr_t dma_addr, u32 len) { struct musb_dma_channel *musb_channel = channel->private_data; DBG(2, "ep%d-%s pkt_sz %d, dma_addr 0x%x length %d, mode %d\n", musb_channel->epnum, musb_channel->transmit ? "Tx" : "Rx", packet_sz, dma_addr, len, mode); BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN || channel->status == MUSB_DMA_STATUS_BUSY); channel->actual_len = 0; musb_channel->start_addr = dma_addr; musb_channel->len = len; musb_channel->max_packet_sz = packet_sz; channel->status = MUSB_DMA_STATUS_BUSY; configure_channel(channel, packet_sz, mode, dma_addr, len); return true; } static int dma_channel_abort(struct dma_channel *channel) { struct musb_dma_channel *musb_channel = channel->private_data; void __iomem *mbase = musb_channel->controller->base; u8 bchannel = musb_channel->idx; int offset; u16 csr; if (channel->status == MUSB_DMA_STATUS_BUSY) { if (musb_channel->transmit) { offset = MUSB_EP_OFFSET(musb_channel->epnum, MUSB_TXCSR); /* * The programming guide says that we must clear * the DMAENAB bit before the DMAMODE bit... */ csr = musb_readw(mbase, offset); csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB); musb_writew(mbase, offset, csr); csr &= ~MUSB_TXCSR_DMAMODE; musb_writew(mbase, offset, csr); } else { offset = MUSB_EP_OFFSET(musb_channel->epnum, MUSB_RXCSR); csr = musb_readw(mbase, offset); csr &= ~(MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAENAB | MUSB_RXCSR_DMAMODE); musb_writew(mbase, offset, csr); } musb_writew(mbase, MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL), 0); musb_write_hsdma_addr(mbase, bchannel, 0); musb_write_hsdma_count(mbase, bchannel, 0); channel->status = MUSB_DMA_STATUS_FREE; } return 0; } static irqreturn_t dma_controller_irq(int irq, void *private_data) { struct musb_dma_controller *controller = private_data; struct musb *musb = controller->private_data; struct musb_dma_channel *musb_channel; struct dma_channel *channel; void __iomem *mbase = controller->base; irqreturn_t retval = IRQ_NONE; unsigned long flags; u8 bchannel; u8 int_hsdma; u32 addr, count; u16 csr; spin_lock_irqsave(&musb->lock, flags); int_hsdma = musb_readb(mbase, MUSB_HSDMA_INTR); #ifdef CONFIG_BLACKFIN /* Clear DMA interrupt flags */ musb_writeb(mbase, MUSB_HSDMA_INTR, int_hsdma); #endif if (!int_hsdma) { DBG(2, "spurious DMA irq\n"); for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) { musb_channel = (struct musb_dma_channel *) &(controller->channel[bchannel]); channel = &musb_channel->channel; if (channel->status == MUSB_DMA_STATUS_BUSY) { count = musb_read_hsdma_count(mbase, bchannel); if (count == 0) int_hsdma |= (1 << bchannel); } } DBG(2, "int_hsdma = 0x%x\n", int_hsdma); if (!int_hsdma) goto done; } for (bchannel = 0; bchannel < MUSB_HSDMA_CHANNELS; bchannel++) { if (int_hsdma & (1 << bchannel)) { musb_channel = (struct musb_dma_channel *) &(controller->channel[bchannel]); channel = &musb_channel->channel; csr = musb_readw(mbase, MUSB_HSDMA_CHANNEL_OFFSET(bchannel, MUSB_HSDMA_CONTROL)); if (csr & (1 << MUSB_HSDMA_BUSERROR_SHIFT)) { musb_channel->channel.status = MUSB_DMA_STATUS_BUS_ABORT; } else { u8 devctl; addr = musb_read_hsdma_addr(mbase, bchannel); channel->actual_len = addr - musb_channel->start_addr; DBG(2, "ch %p, 0x%x -> 0x%x (%zu / %d) %s\n", channel, musb_channel->start_addr, addr, channel->actual_len, musb_channel->len, (channel->actual_len < musb_channel->len) ? "=> reconfig 0" : "=> complete"); devctl = musb_readb(mbase, MUSB_DEVCTL); channel->status = MUSB_DMA_STATUS_FREE; /* completed */ if ((devctl & MUSB_DEVCTL_HM) && (musb_channel->transmit) && ((channel->desired_mode == 0) || (channel->actual_len & (musb_channel->max_packet_sz - 1))) ) { u8 epnum = musb_channel->epnum; int offset = MUSB_EP_OFFSET(epnum, MUSB_TXCSR); u16 txcsr; /* * The programming guide says that we * must clear DMAENAB before DMAMODE. */ musb_ep_select(mbase, epnum); txcsr = musb_readw(mbase, offset); txcsr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_AUTOSET); musb_writew(mbase, offset, txcsr); /* Send out the packet */ txcsr &= ~MUSB_TXCSR_DMAMODE; txcsr |= MUSB_TXCSR_TXPKTRDY; musb_writew(mbase, offset, txcsr); } musb_dma_completion(musb, musb_channel->epnum, musb_channel->transmit); } } } retval = IRQ_HANDLED; done: spin_unlock_irqrestore(&musb->lock, flags); return retval; } void dma_controller_destroy(struct dma_controller *c) { struct musb_dma_controller *controller = container_of(c, struct musb_dma_controller, controller); if (!controller) return; if (controller->irq) free_irq(controller->irq, c); kfree(controller); } struct dma_controller *__init dma_controller_create(struct musb *musb, void __iomem *base) { struct musb_dma_controller *controller; struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev); int irq = platform_get_irq(pdev, 1); if (irq == 0) { dev_err(dev, "No DMA interrupt line!\n"); return NULL; } controller = kzalloc(sizeof(*controller), GFP_KERNEL); if (!controller) return NULL; controller->channel_count = MUSB_HSDMA_CHANNELS; controller->private_data = musb; controller->base = base; controller->controller.start = dma_controller_start; controller->controller.stop = dma_controller_stop; controller->controller.channel_alloc = dma_channel_allocate; controller->controller.channel_release = dma_channel_release; controller->controller.channel_program = dma_channel_program; controller->controller.channel_abort = dma_channel_abort; if (request_irq(irq, dma_controller_irq, IRQF_DISABLED, dev_name(musb->controller), &controller->controller)) { dev_err(dev, "request_irq %d failed!\n", irq); dma_controller_destroy(&controller->controller); return NULL; } controller->irq = irq; return &controller->controller; }