LXR linux/arch/mips/alchemy/common/dma.c

   1/*
   2 *
   3 * BRIEF MODULE DESCRIPTION
   4 *      A DMA channel allocator for Au1x00. API is modeled loosely off of
   5 *      linux/kernel/dma.c.
   6 *
   7 * Copyright 2000, 2008 MontaVista Software Inc.
   8 * Author: MontaVista Software, Inc. <source@mvista.com>
   9 * Copyright (C) 2005 Ralf Baechle (ralf@linux-mips.org)
  10 *
  11 *  This program is free software; you can redistribute  it and/or modify it
  12 *  under  the terms of  the GNU General  Public License as published by the
  13 *  Free Software Foundation;  either version 2 of the  License, or (at your
  14 *  option) any later version.
  15 *
  16 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  17 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  18 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  19 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  20 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  22 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  23 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  24 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 *
  27 *  You should have received a copy of the  GNU General Public License along
  28 *  with this program; if not, write  to the Free Software Foundation, Inc.,
  29 *  675 Mass Ave, Cambridge, MA 02139, USA.
  30 *
  31 */
  32
  33#include <linux/init.h>
  34#include <linux/export.h>
  35#include <linux/kernel.h>
  36#include <linux/errno.h>
  37#include <linux/spinlock.h>
  38#include <linux/interrupt.h>
  39
  40#include <asm/mach-au1x00/au1000.h>
  41#include <asm/mach-au1x00/au1000_dma.h>
  42
  43/*
  44 * A note on resource allocation:
  45 *
  46 * All drivers needing DMA channels, should allocate and release them
  47 * through the public routines `request_dma()' and `free_dma()'.
  48 *
  49 * In order to avoid problems, all processes should allocate resources in
  50 * the same sequence and release them in the reverse order.
  51 *
  52 * So, when allocating DMAs and IRQs, first allocate the DMA, then the IRQ.
  53 * When releasing them, first release the IRQ, then release the DMA. The
  54 * main reason for this order is that, if you are requesting the DMA buffer
  55 * done interrupt, you won't know the irq number until the DMA channel is
  56 * returned from request_dma.
  57 */
  58
  59/* DMA Channel register block spacing */
  60#define DMA_CHANNEL_LEN         0x00000100
  61
  62DEFINE_SPINLOCK(au1000_dma_spin_lock);
  63
  64struct dma_chan au1000_dma_table[NUM_AU1000_DMA_CHANNELS] = {
  65      {.dev_id = -1,},
  66      {.dev_id = -1,},
  67      {.dev_id = -1,},
  68      {.dev_id = -1,},
  69      {.dev_id = -1,},
  70      {.dev_id = -1,},
  71      {.dev_id = -1,},
  72      {.dev_id = -1,}
  73};
  74EXPORT_SYMBOL(au1000_dma_table);
  75
  76/* Device FIFO addresses and default DMA modes */
  77static const struct dma_dev {
  78        unsigned int fifo_addr;
  79        unsigned int dma_mode;
  80} dma_dev_table[DMA_NUM_DEV] = {
  81        { AU1000_UART0_PHYS_ADDR + 0x04, DMA_DW8 },             /* UART0_TX */
  82        { AU1000_UART0_PHYS_ADDR + 0x00, DMA_DW8 | DMA_DR },    /* UART0_RX */
  83        { 0, 0 },       /* DMA_REQ0 */
  84        { 0, 0 },       /* DMA_REQ1 */
  85        { AU1000_AC97_PHYS_ADDR + 0x08, DMA_DW16 },             /* AC97 TX c */
  86        { AU1000_AC97_PHYS_ADDR + 0x08, DMA_DW16 | DMA_DR },    /* AC97 RX c */
  87        { AU1000_UART3_PHYS_ADDR + 0x04, DMA_DW8 | DMA_NC },    /* UART3_TX */
  88        { AU1000_UART3_PHYS_ADDR + 0x00, DMA_DW8 | DMA_NC | DMA_DR }, /* UART3_RX */
  89        { AU1000_USB_UDC_PHYS_ADDR + 0x00, DMA_DW8 | DMA_NC | DMA_DR }, /* EP0RD */
  90        { AU1000_USB_UDC_PHYS_ADDR + 0x04, DMA_DW8 | DMA_NC }, /* EP0WR */
  91        { AU1000_USB_UDC_PHYS_ADDR + 0x08, DMA_DW8 | DMA_NC }, /* EP2WR */
  92        { AU1000_USB_UDC_PHYS_ADDR + 0x0c, DMA_DW8 | DMA_NC }, /* EP3WR */
  93        { AU1000_USB_UDC_PHYS_ADDR + 0x10, DMA_DW8 | DMA_NC | DMA_DR }, /* EP4RD */
  94        { AU1000_USB_UDC_PHYS_ADDR + 0x14, DMA_DW8 | DMA_NC | DMA_DR }, /* EP5RD */
  95        /* on Au1500, these 2 are DMA_REQ2/3 (GPIO208/209) instead! */
  96        { AU1000_I2S_PHYS_ADDR + 0x00, DMA_DW32 | DMA_NC},      /* I2S TX */
  97        { AU1000_I2S_PHYS_ADDR + 0x00, DMA_DW32 | DMA_NC | DMA_DR}, /* I2S RX */
  98};
  99
 100int au1000_dma_read_proc(char *buf, char **start, off_t fpos,
 101                         int length, int *eof, void *data)
 102{
 103        int i, len = 0;
 104        struct dma_chan *chan;
 105
 106        for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++) {
 107                chan = get_dma_chan(i);
 108                if (chan != NULL)
 109                        len += sprintf(buf + len, "%2d: %s\n",
 110                                       i, chan->dev_str);
 111        }
 112
 113        if (fpos >= len) {
 114                *start = buf;
 115                *eof = 1;
 116                return 0;
 117        }
 118        *start = buf + fpos;
 119        len -= fpos;
 120        if (len > length)
 121                return length;
 122        *eof = 1;
 123        return len;
 124}
 125
 126/* Device FIFO addresses and default DMA modes - 2nd bank */
 127static const struct dma_dev dma_dev_table_bank2[DMA_NUM_DEV_BANK2] = {
 128        { AU1100_SD0_PHYS_ADDR + 0x00, DMA_DS | DMA_DW8 },              /* coherent */
 129        { AU1100_SD0_PHYS_ADDR + 0x04, DMA_DS | DMA_DW8 | DMA_DR },     /* coherent */
 130        { AU1100_SD1_PHYS_ADDR + 0x00, DMA_DS | DMA_DW8 },              /* coherent */
 131        { AU1100_SD1_PHYS_ADDR + 0x04, DMA_DS | DMA_DW8 | DMA_DR }      /* coherent */
 132};
 133
 134void dump_au1000_dma_channel(unsigned int dmanr)
 135{
 136        struct dma_chan *chan;
 137
 138        if (dmanr >= NUM_AU1000_DMA_CHANNELS)
 139                return;
 140        chan = &au1000_dma_table[dmanr];
 141
 142        printk(KERN_INFO "Au1000 DMA%d Register Dump:\n", dmanr);
 143        printk(KERN_INFO "  mode = 0x%08x\n",
 144               __raw_readl(chan->io + DMA_MODE_SET));
 145        printk(KERN_INFO "  addr = 0x%08x\n",
 146               __raw_readl(chan->io + DMA_PERIPHERAL_ADDR));
 147        printk(KERN_INFO "  start0 = 0x%08x\n",
 148               __raw_readl(chan->io + DMA_BUFFER0_START));
 149        printk(KERN_INFO "  start1 = 0x%08x\n",
 150               __raw_readl(chan->io + DMA_BUFFER1_START));
 151        printk(KERN_INFO "  count0 = 0x%08x\n",
 152               __raw_readl(chan->io + DMA_BUFFER0_COUNT));
 153        printk(KERN_INFO "  count1 = 0x%08x\n",
 154               __raw_readl(chan->io + DMA_BUFFER1_COUNT));
 155}
 156
 157/*
 158 * Finds a free channel, and binds the requested device to it.
 159 * Returns the allocated channel number, or negative on error.
 160 * Requests the DMA done IRQ if irqhandler != NULL.
 161 */
 162int request_au1000_dma(int dev_id, const char *dev_str,
 163                       irq_handler_t irqhandler,
 164                       unsigned long irqflags,
 165                       void *irq_dev_id)
 166{
 167        struct dma_chan *chan;
 168        const struct dma_dev *dev;
 169        int i, ret;
 170
 171        if (alchemy_get_cputype() == ALCHEMY_CPU_AU1100) {
 172                if (dev_id < 0 || dev_id >= (DMA_NUM_DEV + DMA_NUM_DEV_BANK2))
 173                        return -EINVAL;
 174        } else {
 175                if (dev_id < 0 || dev_id >= DMA_NUM_DEV)
 176                        return -EINVAL;
 177        }
 178
 179        for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++)
 180                if (au1000_dma_table[i].dev_id < 0)
 181                        break;
 182
 183        if (i == NUM_AU1000_DMA_CHANNELS)
 184                return -ENODEV;
 185
 186        chan = &au1000_dma_table[i];
 187
 188        if (dev_id >= DMA_NUM_DEV) {
 189                dev_id -= DMA_NUM_DEV;
 190                dev = &dma_dev_table_bank2[dev_id];
 191        } else
 192                dev = &dma_dev_table[dev_id];
 193
 194        if (irqhandler) {
 195                chan->irq_dev = irq_dev_id;
 196                ret = request_irq(chan->irq, irqhandler, irqflags, dev_str,
 197                                  chan->irq_dev);
 198                if (ret) {
 199                        chan->irq_dev = NULL;
 200                        return ret;
 201                }
 202        } else {
 203                chan->irq_dev = NULL;
 204        }
 205
 206        /* fill it in */
 207        chan->io = (void __iomem *)(KSEG1ADDR(AU1000_DMA_PHYS_ADDR) +
 208                        i * DMA_CHANNEL_LEN);
 209        chan->dev_id = dev_id;
 210        chan->dev_str = dev_str;
 211        chan->fifo_addr = dev->fifo_addr;
 212        chan->mode = dev->dma_mode;
 213
 214        /* initialize the channel before returning */
 215        init_dma(i);
 216
 217        return i;
 218}
 219EXPORT_SYMBOL(request_au1000_dma);
 220
 221void free_au1000_dma(unsigned int dmanr)
 222{
 223        struct dma_chan *chan = get_dma_chan(dmanr);
 224
 225        if (!chan) {
 226                printk(KERN_ERR "Error trying to free DMA%d\n", dmanr);
 227                return;
 228        }
 229
 230        disable_dma(dmanr);
 231        if (chan->irq_dev)
 232                free_irq(chan->irq, chan->irq_dev);
 233
 234        chan->irq_dev = NULL;
 235        chan->dev_id = -1;
 236}
 237EXPORT_SYMBOL(free_au1000_dma);
 238
 239static int __init au1000_dma_init(void)
 240{
 241        int base, i;
 242
 243        switch (alchemy_get_cputype()) {
 244        case ALCHEMY_CPU_AU1000:
 245                base = AU1000_DMA_INT_BASE;
 246                break;
 247        case ALCHEMY_CPU_AU1500:
 248                base = AU1500_DMA_INT_BASE;
 249                break;
 250        case ALCHEMY_CPU_AU1100:
 251                base = AU1100_DMA_INT_BASE;
 252                break;
 253        default:
 254                goto out;
 255        }
 256
 257        for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++)
 258                au1000_dma_table[i].irq = base + i;
 259
 260        printk(KERN_INFO "Alchemy DMA initialized\n");
 261
 262out:
 263        return 0;
 264}
 265arch_initcall(au1000_dma_init);
 266