/* * * BRIEF MODULE DESCRIPTION * A DMA channel allocator for Au1x00. API is modeled loosely off of * linux/kernel/dma.c. * * Copyright 2000, 2008 MontaVista Software Inc. * Author: MontaVista Software, Inc. * Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org) * * 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 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 AUTHOR 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. * * 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., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include #include #include #include #include #include /* * A note on resource allocation: * * All drivers needing DMA channels, should allocate and release them * through the public routines `request_dma()' and `free_dma()'. * * In order to avoid problems, all processes should allocate resources in * the same sequence and release them in the reverse order. * * So, when allocating DMAs and IRQs, first allocate the DMA, then the IRQ. * When releasing them, first release the IRQ, then release the DMA. The * main reason for this order is that, if you are requesting the DMA buffer * done interrupt, you won't know the irq number until the DMA channel is * returned from request_dma. */ /* DMA Channel register block spacing */ #define DMA_CHANNEL_LEN 0x00000100 DEFINE_SPINLOCK(au1000_dma_spin_lock); struct dma_chan au1000_dma_table[NUM_AU1000_DMA_CHANNELS] = { {.dev_id = -1,}, {.dev_id = -1,}, {.dev_id = -1,}, {.dev_id = -1,}, {.dev_id = -1,}, {.dev_id = -1,}, {.dev_id = -1,}, {.dev_id = -1,} }; EXPORT_SYMBOL(au1000_dma_table); /* Device FIFO addresses and default DMA modes */ static const struct dma_dev { unsigned int fifo_addr; unsigned int dma_mode; } dma_dev_table[DMA_NUM_DEV] = { { AU1000_UART0_PHYS_ADDR + 0x04, DMA_DW8 }, /* UART0_TX */ { AU1000_UART0_PHYS_ADDR + 0x00, DMA_DW8 | DMA_DR }, /* UART0_RX */ { 0, 0 }, /* DMA_REQ0 */ { 0, 0 }, /* DMA_REQ1 */ { AU1000_AC97_PHYS_ADDR + 0x08, DMA_DW16 }, /* AC97 TX c */ { AU1000_AC97_PHYS_ADDR + 0x08, DMA_DW16 | DMA_DR }, /* AC97 RX c */ { AU1000_UART3_PHYS_ADDR + 0x04, DMA_DW8 | DMA_NC }, /* UART3_TX */ { AU1000_UART3_PHYS_ADDR + 0x00, DMA_DW8 | DMA_NC | DMA_DR }, /* UART3_RX */ { AU1000_USB_UDC_PHYS_ADDR + 0x00, DMA_DW8 | DMA_NC | DMA_DR }, /* EP0RD */ { AU1000_USB_UDC_PHYS_ADDR + 0x04, DMA_DW8 | DMA_NC }, /* EP0WR */ { AU1000_USB_UDC_PHYS_ADDR + 0x08, DMA_DW8 | DMA_NC }, /* EP2WR */ { AU1000_USB_UDC_PHYS_ADDR + 0x0c, DMA_DW8 | DMA_NC }, /* EP3WR */ { AU1000_USB_UDC_PHYS_ADDR + 0x10, DMA_DW8 | DMA_NC | DMA_DR }, /* EP4RD */ { AU1000_USB_UDC_PHYS_ADDR + 0x14, DMA_DW8 | DMA_NC | DMA_DR }, /* EP5RD */ /* on Au1500, these 2 are DMA_REQ2/3 (GPIO208/209) instead! */ { AU1000_I2S_PHYS_ADDR + 0x00, DMA_DW32 | DMA_NC}, /* I2S TX */ { AU1000_I2S_PHYS_ADDR + 0x00, DMA_DW32 | DMA_NC | DMA_DR}, /* I2S RX */ }; int au1000_dma_read_proc(char *buf, char **start, off_t fpos, int length, int *eof, void *data) { int i, len = 0; struct dma_chan *chan; for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) { chan = get_dma_chan(i); if (chan != NULL) len += sprintf(buf + len, "%2d: %s\n", i, chan->dev_str); } if (fpos >= len) { *start = buf; *eof = 1; return 0; } *start = buf + fpos; len -= fpos; if (len > length) return length; *eof = 1; return len; } /* Device FIFO addresses and default DMA modes - 2nd bank */ static const struct dma_dev dma_dev_table_bank2[DMA_NUM_DEV_BANK2] = { { AU1100_SD0_PHYS_ADDR + 0x00, DMA_DS | DMA_DW8 }, /* coherent */ { AU1100_SD0_PHYS_ADDR + 0x04, DMA_DS | DMA_DW8 | DMA_DR }, /* coherent */ { AU1100_SD1_PHYS_ADDR + 0x00, DMA_DS | DMA_DW8 }, /* coherent */ { AU1100_SD1_PHYS_ADDR + 0x04, DMA_DS | DMA_DW8 | DMA_DR } /* coherent */ }; /* * Finds a free channel, and binds the requested device to it. * Returns the allocated channel number, or negative on error. * Requests the DMA done IRQ if irqhandler != NULL. */ int request_au1000_dma(int dev_id, const char *dev_str, irq_handler_t irqhandler, unsigned long irqflags, void *irq_dev_id) { struct dma_chan *chan; const struct dma_dev *dev; int i, ret; if (alchemy_get_cputype() == ALCHEMY_CPU_AU1100) { if (dev_id < 0 || dev_id >= (DMA_NUM_DEV + DMA_NUM_DEV_BANK2)) return -EINVAL; } else { if (dev_id < 0 || dev_id >= DMA_NUM_DEV) return -EINVAL; } for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) if (au1000_dma_table[i].dev_id < 0) break; if (i == NUM_AU1000_DMA_CHANNELS) return -ENODEV; chan = &au1000_dma_table[i]; if (dev_id >= DMA_NUM_DEV) { dev_id -= DMA_NUM_DEV; dev = &dma_dev_table_bank2[dev_id]; } else dev = &dma_dev_table[dev_id]; if (irqhandler) { chan->irq_dev = irq_dev_id; ret = request_irq(chan->irq, irqhandler, irqflags, dev_str, chan->irq_dev); if (ret) { chan->irq_dev = NULL; return ret; } } else { chan->irq_dev = NULL; } /* fill it in */ chan->io = (void __iomem *)(KSEG1ADDR(AU1000_DMA_PHYS_ADDR) + i * DMA_CHANNEL_LEN); chan->dev_id = dev_id; chan->dev_str = dev_str; chan->fifo_addr = dev->fifo_addr; chan->mode = dev->dma_mode; /* initialize the channel before returning */ init_dma(i); return i; } EXPORT_SYMBOL(request_au1000_dma); void free_au1000_dma(unsigned int dmanr) { struct dma_chan *chan = get_dma_chan(dmanr); if (!chan) { printk(KERN_ERR "Error trying to free DMA%d\n", dmanr); return; } disable_dma(dmanr); if (chan->irq_dev) free_irq(chan->irq, chan->irq_dev); chan->irq_dev = NULL; chan->dev_id = -1; } EXPORT_SYMBOL(free_au1000_dma); static int __init au1000_dma_init(void) { int base, i; switch (alchemy_get_cputype()) { case ALCHEMY_CPU_AU1000: base = AU1000_DMA_INT_BASE; break; case ALCHEMY_CPU_AU1500: base = AU1500_DMA_INT_BASE; break; case ALCHEMY_CPU_AU1100: base = AU1100_DMA_INT_BASE; break; default: goto out; } for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) au1000_dma_table[i].irq = base + i; printk(KERN_INFO "Alchemy DMA initialized\n"); out: return 0; } arch_initcall(au1000_dma_init);