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
  62 DEFINE_SPINLOCK(au1000_dma_spin_lock);
  63
  64 struct 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 };
  74 EXPORT_SYMBOL(au1000_dma_table);
  75
  76 /* Device FIFO addresses and default DMA modes */
  77 static 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
 100 int 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 */
 127 static 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
 134 /*
 135  * Finds a free channel, and binds the requested device to it.
 136  * Returns the allocated channel number, or negative on error.
 137  * Requests the DMA done IRQ if irqhandler != NULL.
 138  */
 139 int request_au1000_dma(int dev_id, const char *dev_str,
 140                        irq_handler_t irqhandler,
 141                        unsigned long irqflags,
 142                        void *irq_dev_id)
 143 {
 144         struct dma_chan *chan;
 145         const struct dma_dev *dev;
 146         int i, ret;
 147
 148         if (alchemy_get_cputype() == ALCHEMY_CPU_AU1100) {
 149                 if (dev_id < 0 || dev_id >= (DMA_NUM_DEV + DMA_NUM_DEV_BANK2))
 150                         return -EINVAL;
 151         } else {
 152                 if (dev_id < 0 || dev_id >= DMA_NUM_DEV)
 153                         return -EINVAL;
 154         }
 155
 156         for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++)
 157                 if (au1000_dma_table[i].dev_id < 0)
 158                         break;
 159
 160         if (i == NUM_AU1000_DMA_CHANNELS)
 161                 return -ENODEV;
 162
 163         chan = &au1000_dma_table[i];
 164
 165         if (dev_id >= DMA_NUM_DEV) {
 166                 dev_id -= DMA_NUM_DEV;
 167                 dev = &dma_dev_table_bank2[dev_id];
 168         } else
 169                 dev = &dma_dev_table[dev_id];
 170
 171         if (irqhandler) {
 172                 chan->irq_dev = irq_dev_id;
 173                 ret = request_irq(chan->irq, irqhandler, irqflags, dev_str,
 174                                   chan->irq_dev);
 175                 if (ret) {
 176                         chan->irq_dev = NULL;
 177                         return ret;
 178                 }
 179         } else {
 180                 chan->irq_dev = NULL;
 181         }
 182
 183         /* fill it in */
 184         chan->io = (void __iomem *)(KSEG1ADDR(AU1000_DMA_PHYS_ADDR) +
 185                         i * DMA_CHANNEL_LEN);
 186         chan->dev_id = dev_id;
 187         chan->dev_str = dev_str;
 188         chan->fifo_addr = dev->fifo_addr;
 189         chan->mode = dev->dma_mode;
 190
 191         /* initialize the channel before returning */
 192         init_dma(i);
 193
 194         return i;
 195 }
 196 EXPORT_SYMBOL(request_au1000_dma);
 197
 198 void free_au1000_dma(unsigned int dmanr)
 199 {
 200         struct dma_chan *chan = get_dma_chan(dmanr);
 201
 202         if (!chan) {
 203                 printk(KERN_ERR "Error trying to free DMA%d\n", dmanr);
 204                 return;
 205         }
 206
 207         disable_dma(dmanr);
 208         if (chan->irq_dev)
 209                 free_irq(chan->irq, chan->irq_dev);
 210
 211         chan->irq_dev = NULL;
 212         chan->dev_id = -1;
 213 }
 214 EXPORT_SYMBOL(free_au1000_dma);
 215
 216 static int __init au1000_dma_init(void)
 217 {
 218         int base, i;
 219
 220         switch (alchemy_get_cputype()) {
 221         case ALCHEMY_CPU_AU1000:
 222                 base = AU1000_DMA_INT_BASE;
 223                 break;
 224         case ALCHEMY_CPU_AU1500:
 225                 base = AU1500_DMA_INT_BASE;
 226                 break;
 227         case ALCHEMY_CPU_AU1100:
 228                 base = AU1100_DMA_INT_BASE;
 229                 break;
 230         default:
 231                 goto out;
 232         }
 233
 234         for (i = 0; i < NUM_AU1000_DMA_CHANNELS; i++)
 235                 au1000_dma_table[i].irq = base + i;
 236
 237         printk(KERN_INFO "Alchemy DMA initialized\n");
 238
 239 out:
 240         return 0;
 241 }
 242 arch_initcall(au1000_dma_init);