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Diffstat (limited to 'arch/mips/alchemy/common/dma.c')
| -rw-r--r-- | arch/mips/alchemy/common/dma.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/arch/mips/alchemy/common/dma.c b/arch/mips/alchemy/common/dma.c new file mode 100644 index 00000000000..d6fbda232e6 --- /dev/null +++ b/arch/mips/alchemy/common/dma.c @@ -0,0 +1,238 @@ +/* + * + * 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. <source@mvista.com> + * 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 <linux/module.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> + +#include <asm/mach-au1x00/au1000.h> +#include <asm/mach-au1x00/au1000_dma.h> + +#if defined(CONFIG_SOC_AU1000) || defined(CONFIG_SOC_AU1500) || \ + defined(CONFIG_SOC_AU1100) +/* + * 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. + */ + +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] = { + {UART0_ADDR + UART_TX, 0}, + {UART0_ADDR + UART_RX, 0}, + {0, 0}, + {0, 0}, + {AC97C_DATA, DMA_DW16 }, /* coherent */ + {AC97C_DATA, DMA_DR | DMA_DW16 }, /* coherent */ + {UART3_ADDR + UART_TX, DMA_DW8 | DMA_NC}, + {UART3_ADDR + UART_RX, DMA_DR | DMA_DW8 | DMA_NC}, + {USBD_EP0RD, DMA_DR | DMA_DW8 | DMA_NC}, + {USBD_EP0WR, DMA_DW8 | DMA_NC}, + {USBD_EP2WR, DMA_DW8 | DMA_NC}, + {USBD_EP3WR, DMA_DW8 | DMA_NC}, + {USBD_EP4RD, DMA_DR | DMA_DW8 | DMA_NC}, + {USBD_EP5RD, DMA_DR | DMA_DW8 | DMA_NC}, + {I2S_DATA, DMA_DW32 | DMA_NC}, + {I2S_DATA, DMA_DR | DMA_DW32 | DMA_NC} +}; + +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] = { + { SD0_XMIT_FIFO, DMA_DS | DMA_DW8 }, /* coherent */ + { SD0_RECV_FIFO, DMA_DS | DMA_DR | DMA_DW8 }, /* coherent */ + { SD1_XMIT_FIFO, DMA_DS | DMA_DW8 }, /* coherent */ + { SD1_RECV_FIFO, DMA_DS | DMA_DR | DMA_DW8 } /* coherent */ +}; + +void dump_au1000_dma_channel(unsigned int dmanr) +{ + struct dma_chan *chan; + + if (dmanr >= NUM_AU1000_DMA_CHANNELS) + return; + chan = &au1000_dma_table[dmanr]; + + printk(KERN_INFO "Au1000 DMA%d Register Dump:\n", dmanr); + printk(KERN_INFO " mode = 0x%08x\n", + au_readl(chan->io + DMA_MODE_SET)); + printk(KERN_INFO " addr = 0x%08x\n", + au_readl(chan->io + DMA_PERIPHERAL_ADDR)); + printk(KERN_INFO " start0 = 0x%08x\n", + au_readl(chan->io + DMA_BUFFER0_START)); + printk(KERN_INFO " start1 = 0x%08x\n", + au_readl(chan->io + DMA_BUFFER1_START)); + printk(KERN_INFO " count0 = 0x%08x\n", + au_readl(chan->io + DMA_BUFFER0_COUNT)); + printk(KERN_INFO " count1 = 0x%08x\n", + au_readl(chan->io + DMA_BUFFER1_COUNT)); +} + +/* + * 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 defined(CONFIG_SOC_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; +#endif + + 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 = AU1000_DMA_INT_BASE + i; + chan->irq_dev = irq_dev_id; + ret = request_irq(chan->irq, irqhandler, irqflags, dev_str, + chan->irq_dev); + if (ret) { + chan->irq = 0; + chan->irq_dev = NULL; + return ret; + } + } else { + chan->irq = 0; + chan->irq_dev = NULL; + } + + /* fill it in */ + chan->io = DMA_CHANNEL_BASE + 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) + free_irq(chan->irq, chan->irq_dev); + + chan->irq = 0; + chan->irq_dev = NULL; + chan->dev_id = -1; +} +EXPORT_SYMBOL(free_au1000_dma); + +#endif /* AU1000 AU1500 AU1100 */ |