arch/mips/lantiq/xway/dma.c

   1 /*
   2  *   This program is free software; you can redistribute it and/or modify it
   3  *   under the terms of the GNU General Public License version 2 as published
   4  *   by the Free Software Foundation.
   5  *
   6  *   This program is distributed in the hope that it will be useful,
   7  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  *   GNU General Public License for more details.
  10  *
  11  *   You should have received a copy of the GNU General Public License
  12  *   along with this program; if not, write to the Free Software
  13  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
  14  *
  15  *   Copyright (C) 2011 John Crispin <blogic@openwrt.org>
  16  */
  17
  18 #include <linux/init.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/io.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/module.h>
  23 #include <linux/clk.h>
  24 #include <linux/err.h>
  25
  26 #include <lantiq_soc.h>
  27 #include <xway_dma.h>
  28
  29 #define LTQ_DMA_ID              0x08
  30 #define LTQ_DMA_CTRL            0x10
  31 #define LTQ_DMA_CPOLL           0x14
  32 #define LTQ_DMA_CS              0x18
  33 #define LTQ_DMA_CCTRL           0x1C
  34 #define LTQ_DMA_CDBA            0x20
  35 #define LTQ_DMA_CDLEN           0x24
  36 #define LTQ_DMA_CIS             0x28
  37 #define LTQ_DMA_CIE             0x2C
  38 #define LTQ_DMA_PS              0x40
  39 #define LTQ_DMA_PCTRL           0x44
  40 #define LTQ_DMA_IRNEN           0xf4
  41
  42 #define DMA_DESCPT              BIT(3)          /* descriptor complete irq */
  43 #define DMA_TX                  BIT(8)          /* TX channel direction */
  44 #define DMA_CHAN_ON             BIT(0)          /* channel on / off bit */
  45 #define DMA_PDEN                BIT(6)          /* enable packet drop */
  46 #define DMA_CHAN_RST            BIT(1)          /* channel on / off bit */
  47 #define DMA_RESET               BIT(0)          /* channel on / off bit */
  48 #define DMA_IRQ_ACK             0x7e            /* IRQ status register */
  49 #define DMA_POLL                BIT(31)         /* turn on channel polling */
  50 #define DMA_CLK_DIV4            BIT(6)          /* polling clock divider */
  51 #define DMA_2W_BURST            BIT(1)          /* 2 word burst length */
  52 #define DMA_MAX_CHANNEL         20              /* the soc has 20 channels */
  53 #define DMA_ETOP_ENDIANNESS     (0xf << 8) /* endianness swap etop channels */
  54 #define DMA_WEIGHT      (BIT(17) | BIT(16))     /* default channel wheight */
  55
  56 #define ltq_dma_r32(x)                  ltq_r32(ltq_dma_membase + (x))
  57 #define ltq_dma_w32(x, y)               ltq_w32(x, ltq_dma_membase + (y))
  58 #define ltq_dma_w32_mask(x, y, z)       ltq_w32_mask(x, y, \
  59                                                 ltq_dma_membase + (z))
  60
  61 static void __iomem *ltq_dma_membase;
  62
  63 void
  64 ltq_dma_enable_irq(struct ltq_dma_channel *ch)
  65 {
  66         unsigned long flags;
  67
  68         local_irq_save(flags);
  69         ltq_dma_w32(ch->nr, LTQ_DMA_CS);
  70         ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
  71         local_irq_restore(flags);
  72 }
  73 EXPORT_SYMBOL_GPL(ltq_dma_enable_irq);
  74
  75 void
  76 ltq_dma_disable_irq(struct ltq_dma_channel *ch)
  77 {
  78         unsigned long flags;
  79
  80         local_irq_save(flags);
  81         ltq_dma_w32(ch->nr, LTQ_DMA_CS);
  82         ltq_dma_w32_mask(1 << ch->nr, 0, LTQ_DMA_IRNEN);
  83         local_irq_restore(flags);
  84 }
  85 EXPORT_SYMBOL_GPL(ltq_dma_disable_irq);
  86
  87 void
  88 ltq_dma_ack_irq(struct ltq_dma_channel *ch)
  89 {
  90         unsigned long flags;
  91
  92         local_irq_save(flags);
  93         ltq_dma_w32(ch->nr, LTQ_DMA_CS);
  94         ltq_dma_w32(DMA_IRQ_ACK, LTQ_DMA_CIS);
  95         local_irq_restore(flags);
  96 }
  97 EXPORT_SYMBOL_GPL(ltq_dma_ack_irq);
  98
  99 void
 100 ltq_dma_open(struct ltq_dma_channel *ch)
 101 {
 102         unsigned long flag;
 103
 104         local_irq_save(flag);
 105         ltq_dma_w32(ch->nr, LTQ_DMA_CS);
 106         ltq_dma_w32_mask(0, DMA_CHAN_ON, LTQ_DMA_CCTRL);
 107         ltq_dma_enable_irq(ch);
 108         local_irq_restore(flag);
 109 }
 110 EXPORT_SYMBOL_GPL(ltq_dma_open);
 111
 112 void
 113 ltq_dma_close(struct ltq_dma_channel *ch)
 114 {
 115         unsigned long flag;
 116
 117         local_irq_save(flag);
 118         ltq_dma_w32(ch->nr, LTQ_DMA_CS);
 119         ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL);
 120         ltq_dma_disable_irq(ch);
 121         local_irq_restore(flag);
 122 }
 123 EXPORT_SYMBOL_GPL(ltq_dma_close);
 124
 125 static void
 126 ltq_dma_alloc(struct ltq_dma_channel *ch)
 127 {
 128         unsigned long flags;
 129
 130         ch->desc = 0;
 131         ch->desc_base = dma_alloc_coherent(NULL,
 132                                 LTQ_DESC_NUM * LTQ_DESC_SIZE,
 133                                 &ch->phys, GFP_ATOMIC);
 134         memset(ch->desc_base, 0, LTQ_DESC_NUM * LTQ_DESC_SIZE);
 135
 136         local_irq_save(flags);
 137         ltq_dma_w32(ch->nr, LTQ_DMA_CS);
 138         ltq_dma_w32(ch->phys, LTQ_DMA_CDBA);
 139         ltq_dma_w32(LTQ_DESC_NUM, LTQ_DMA_CDLEN);
 140         ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL);
 141         wmb();
 142         ltq_dma_w32_mask(0, DMA_CHAN_RST, LTQ_DMA_CCTRL);
 143         while (ltq_dma_r32(LTQ_DMA_CCTRL) & DMA_CHAN_RST)
 144                 ;
 145         local_irq_restore(flags);
 146 }
 147
 148 void
 149 ltq_dma_alloc_tx(struct ltq_dma_channel *ch)
 150 {
 151         unsigned long flags;
 152
 153         ltq_dma_alloc(ch);
 154
 155         local_irq_save(flags);
 156         ltq_dma_w32(DMA_DESCPT, LTQ_DMA_CIE);
 157         ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
 158         ltq_dma_w32(DMA_WEIGHT | DMA_TX, LTQ_DMA_CCTRL);
 159         local_irq_restore(flags);
 160 }
 161 EXPORT_SYMBOL_GPL(ltq_dma_alloc_tx);
 162
 163 void
 164 ltq_dma_alloc_rx(struct ltq_dma_channel *ch)
 165 {
 166         unsigned long flags;
 167
 168         ltq_dma_alloc(ch);
 169
 170         local_irq_save(flags);
 171         ltq_dma_w32(DMA_DESCPT, LTQ_DMA_CIE);
 172         ltq_dma_w32_mask(0, 1 << ch->nr, LTQ_DMA_IRNEN);
 173         ltq_dma_w32(DMA_WEIGHT, LTQ_DMA_CCTRL);
 174         local_irq_restore(flags);
 175 }
 176 EXPORT_SYMBOL_GPL(ltq_dma_alloc_rx);
 177
 178 void
 179 ltq_dma_free(struct ltq_dma_channel *ch)
 180 {
 181         if (!ch->desc_base)
 182                 return;
 183         ltq_dma_close(ch);
 184         dma_free_coherent(NULL, LTQ_DESC_NUM * LTQ_DESC_SIZE,
 185                 ch->desc_base, ch->phys);
 186 }
 187 EXPORT_SYMBOL_GPL(ltq_dma_free);
 188
 189 void
 190 ltq_dma_init_port(int p)
 191 {
 192         ltq_dma_w32(p, LTQ_DMA_PS);
 193         switch (p) {
 194         case DMA_PORT_ETOP:
 195                 /*
 196                  * Tell the DMA engine to swap the endianness of data frames and
 197                  * drop packets if the channel arbitration fails.
 198                  */
 199                 ltq_dma_w32_mask(0, DMA_ETOP_ENDIANNESS | DMA_PDEN,
 200                         LTQ_DMA_PCTRL);
 201                 break;
 202
 203         case DMA_PORT_DEU:
 204                 ltq_dma_w32((DMA_2W_BURST << 4) | (DMA_2W_BURST << 2),
 205                         LTQ_DMA_PCTRL);
 206                 break;
 207
 208         default:
 209                 break;
 210         }
 211 }
 212 EXPORT_SYMBOL_GPL(ltq_dma_init_port);
 213
 214 static int
 215 ltq_dma_init(struct platform_device *pdev)
 216 {
 217         struct clk *clk;
 218         struct resource *res;
 219         unsigned id;
 220         int i;
 221
 222         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 223         if (!res)
 224                 panic("Failed to get dma resource");
 225
 226         /* remap dma register range */
 227         ltq_dma_membase = devm_ioremap_resource(&pdev->dev, res);
 228         if (IS_ERR(ltq_dma_membase))
 229                 panic("Failed to remap dma resource");
 230
 231         /* power up and reset the dma engine */
 232         clk = clk_get(&pdev->dev, NULL);
 233         if (IS_ERR(clk))
 234                 panic("Failed to get dma clock");
 235
 236         clk_enable(clk);
 237         ltq_dma_w32_mask(0, DMA_RESET, LTQ_DMA_CTRL);
 238
 239         /* disable all interrupts */
 240         ltq_dma_w32(0, LTQ_DMA_IRNEN);
 241
 242         /* reset/configure each channel */
 243         for (i = 0; i < DMA_MAX_CHANNEL; i++) {
 244                 ltq_dma_w32(i, LTQ_DMA_CS);
 245                 ltq_dma_w32(DMA_CHAN_RST, LTQ_DMA_CCTRL);
 246                 ltq_dma_w32(DMA_POLL | DMA_CLK_DIV4, LTQ_DMA_CPOLL);
 247                 ltq_dma_w32_mask(DMA_CHAN_ON, 0, LTQ_DMA_CCTRL);
 248         }
 249
 250         id = ltq_dma_r32(LTQ_DMA_ID);
 251         dev_info(&pdev->dev,
 252                 "Init done - hw rev: %X, ports: %d, channels: %d\n",
 253                 id & 0x1f, (id >> 16) & 0xf, id >> 20);
 254
 255         return 0;
 256 }
 257
 258 static const struct of_device_id dma_match[] = {
 259         { .compatible = "lantiq,dma-xway" },
 260         {},
 261 };
 262 MODULE_DEVICE_TABLE(of, dma_match);
 263
 264 static struct platform_driver dma_driver = {
 265         .probe = ltq_dma_init,
 266         .driver = {
 267                 .name = "dma-xway",
 268                 .owner = THIS_MODULE,
 269                 .of_match_table = dma_match,
 270         },
 271 };
 272
 273 int __init
 274 dma_init(void)
 275 {
 276         return platform_driver_register(&dma_driver);
 277 }
 278
 279 postcore_initcall(dma_init);