arch/mips/jz4740/dma.c

   1 /*
   2  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
   3  *  JZ4740 SoC DMA support
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under  the terms of the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the GNU General Public License along
  11  *  with this program; if not, write to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/interrupt.h>
  20
  21 #include <linux/dma-mapping.h>
  22 #include <asm/mach-jz4740/dma.h>
  23 #include <asm/mach-jz4740/base.h>
  24
  25 #define JZ_REG_DMA_SRC_ADDR(x)          (0x00 + (x) * 0x20)
  26 #define JZ_REG_DMA_DST_ADDR(x)          (0x04 + (x) * 0x20)
  27 #define JZ_REG_DMA_TRANSFER_COUNT(x)    (0x08 + (x) * 0x20)
  28 #define JZ_REG_DMA_REQ_TYPE(x)          (0x0C + (x) * 0x20)
  29 #define JZ_REG_DMA_STATUS_CTRL(x)       (0x10 + (x) * 0x20)
  30 #define JZ_REG_DMA_CMD(x)               (0x14 + (x) * 0x20)
  31 #define JZ_REG_DMA_DESC_ADDR(x)         (0x18 + (x) * 0x20)
  32
  33 #define JZ_REG_DMA_CTRL                 0x300
  34 #define JZ_REG_DMA_IRQ                  0x304
  35 #define JZ_REG_DMA_DOORBELL             0x308
  36 #define JZ_REG_DMA_DOORBELL_SET         0x30C
  37
  38 #define JZ_DMA_STATUS_CTRL_NO_DESC              BIT(31)
  39 #define JZ_DMA_STATUS_CTRL_DESC_INV             BIT(6)
  40 #define JZ_DMA_STATUS_CTRL_ADDR_ERR             BIT(4)
  41 #define JZ_DMA_STATUS_CTRL_TRANSFER_DONE        BIT(3)
  42 #define JZ_DMA_STATUS_CTRL_HALT                 BIT(2)
  43 #define JZ_DMA_STATUS_CTRL_COUNT_TERMINATE      BIT(1)
  44 #define JZ_DMA_STATUS_CTRL_ENABLE               BIT(0)
  45
  46 #define JZ_DMA_CMD_SRC_INC                      BIT(23)
  47 #define JZ_DMA_CMD_DST_INC                      BIT(22)
  48 #define JZ_DMA_CMD_RDIL_MASK                    (0xf << 16)
  49 #define JZ_DMA_CMD_SRC_WIDTH_MASK               (0x3 << 14)
  50 #define JZ_DMA_CMD_DST_WIDTH_MASK               (0x3 << 12)
  51 #define JZ_DMA_CMD_INTERVAL_LENGTH_MASK         (0x7 << 8)
  52 #define JZ_DMA_CMD_BLOCK_MODE                   BIT(7)
  53 #define JZ_DMA_CMD_DESC_VALID                   BIT(4)
  54 #define JZ_DMA_CMD_DESC_VALID_MODE              BIT(3)
  55 #define JZ_DMA_CMD_VALID_IRQ_ENABLE             BIT(2)
  56 #define JZ_DMA_CMD_TRANSFER_IRQ_ENABLE          BIT(1)
  57 #define JZ_DMA_CMD_LINK_ENABLE                  BIT(0)
  58
  59 #define JZ_DMA_CMD_FLAGS_OFFSET 22
  60 #define JZ_DMA_CMD_RDIL_OFFSET 16
  61 #define JZ_DMA_CMD_SRC_WIDTH_OFFSET 14
  62 #define JZ_DMA_CMD_DST_WIDTH_OFFSET 12
  63 #define JZ_DMA_CMD_TRANSFER_SIZE_OFFSET 8
  64 #define JZ_DMA_CMD_MODE_OFFSET 7
  65
  66 #define JZ_DMA_CTRL_PRIORITY_MASK       (0x3 << 8)
  67 #define JZ_DMA_CTRL_HALT                BIT(3)
  68 #define JZ_DMA_CTRL_ADDRESS_ERROR       BIT(2)
  69 #define JZ_DMA_CTRL_ENABLE              BIT(0)
  70
  71
  72 static void __iomem *jz4740_dma_base;
  73 static spinlock_t jz4740_dma_lock;
  74
  75 static inline uint32_t jz4740_dma_read(size_t reg)
  76 {
  77         return readl(jz4740_dma_base + reg);
  78 }
  79
  80 static inline void jz4740_dma_write(size_t reg, uint32_t val)
  81 {
  82         writel(val, jz4740_dma_base + reg);
  83 }
  84
  85 static inline void jz4740_dma_write_mask(size_t reg, uint32_t val, uint32_t mask)
  86 {
  87         uint32_t val2;
  88         val2 = jz4740_dma_read(reg);
  89         val2 &= ~mask;
  90         val2 |= val;
  91         jz4740_dma_write(reg, val2);
  92 }
  93
  94 struct jz4740_dma_chan {
  95         unsigned int id;
  96         void *dev;
  97         const char *name;
  98
  99         enum jz4740_dma_flags flags;
 100         uint32_t transfer_shift;
 101
 102         jz4740_dma_complete_callback_t complete_cb;
 103
 104         unsigned used:1;
 105 };
 106
 107 #define JZ4740_DMA_CHANNEL(_id) { .id = _id }
 108
 109 struct jz4740_dma_chan jz4740_dma_channels[] = {
 110         JZ4740_DMA_CHANNEL(0),
 111         JZ4740_DMA_CHANNEL(1),
 112         JZ4740_DMA_CHANNEL(2),
 113         JZ4740_DMA_CHANNEL(3),
 114         JZ4740_DMA_CHANNEL(4),
 115         JZ4740_DMA_CHANNEL(5),
 116 };
 117
 118 struct jz4740_dma_chan *jz4740_dma_request(void *dev, const char *name)
 119 {
 120         unsigned int i;
 121         struct jz4740_dma_chan *dma = NULL;
 122
 123         spin_lock(&jz4740_dma_lock);
 124
 125         for (i = 0; i < ARRAY_SIZE(jz4740_dma_channels); ++i) {
 126                 if (!jz4740_dma_channels[i].used) {
 127                         dma = &jz4740_dma_channels[i];
 128                         dma->used = 1;
 129                         break;
 130                 }
 131         }
 132
 133         spin_unlock(&jz4740_dma_lock);
 134
 135         if (!dma)
 136                 return NULL;
 137
 138         dma->dev = dev;
 139         dma->name = name;
 140
 141         return dma;
 142 }
 143 EXPORT_SYMBOL_GPL(jz4740_dma_request);
 144
 145 void jz4740_dma_configure(struct jz4740_dma_chan *dma,
 146         const struct jz4740_dma_config *config)
 147 {
 148         uint32_t cmd;
 149
 150         switch (config->transfer_size) {
 151         case JZ4740_DMA_TRANSFER_SIZE_2BYTE:
 152                 dma->transfer_shift = 1;
 153                 break;
 154         case JZ4740_DMA_TRANSFER_SIZE_4BYTE:
 155                 dma->transfer_shift = 2;
 156                 break;
 157         case JZ4740_DMA_TRANSFER_SIZE_16BYTE:
 158                 dma->transfer_shift = 4;
 159                 break;
 160         case JZ4740_DMA_TRANSFER_SIZE_32BYTE:
 161                 dma->transfer_shift = 5;
 162                 break;
 163         default:
 164                 dma->transfer_shift = 0;
 165                 break;
 166         }
 167
 168         cmd = config->flags << JZ_DMA_CMD_FLAGS_OFFSET;
 169         cmd |= config->src_width << JZ_DMA_CMD_SRC_WIDTH_OFFSET;
 170         cmd |= config->dst_width << JZ_DMA_CMD_DST_WIDTH_OFFSET;
 171         cmd |= config->transfer_size << JZ_DMA_CMD_TRANSFER_SIZE_OFFSET;
 172         cmd |= config->mode << JZ_DMA_CMD_MODE_OFFSET;
 173         cmd |= JZ_DMA_CMD_TRANSFER_IRQ_ENABLE;
 174
 175         jz4740_dma_write(JZ_REG_DMA_CMD(dma->id), cmd);
 176         jz4740_dma_write(JZ_REG_DMA_STATUS_CTRL(dma->id), 0);
 177         jz4740_dma_write(JZ_REG_DMA_REQ_TYPE(dma->id), config->request_type);
 178 }
 179 EXPORT_SYMBOL_GPL(jz4740_dma_configure);
 180
 181 void jz4740_dma_set_src_addr(struct jz4740_dma_chan *dma, dma_addr_t src)
 182 {
 183         jz4740_dma_write(JZ_REG_DMA_SRC_ADDR(dma->id), src);
 184 }
 185 EXPORT_SYMBOL_GPL(jz4740_dma_set_src_addr);
 186
 187 void jz4740_dma_set_dst_addr(struct jz4740_dma_chan *dma, dma_addr_t dst)
 188 {
 189         jz4740_dma_write(JZ_REG_DMA_DST_ADDR(dma->id), dst);
 190 }
 191 EXPORT_SYMBOL_GPL(jz4740_dma_set_dst_addr);
 192
 193 void jz4740_dma_set_transfer_count(struct jz4740_dma_chan *dma, uint32_t count)
 194 {
 195         count >>= dma->transfer_shift;
 196         jz4740_dma_write(JZ_REG_DMA_TRANSFER_COUNT(dma->id), count);
 197 }
 198 EXPORT_SYMBOL_GPL(jz4740_dma_set_transfer_count);
 199
 200 void jz4740_dma_set_complete_cb(struct jz4740_dma_chan *dma,
 201         jz4740_dma_complete_callback_t cb)
 202 {
 203         dma->complete_cb = cb;
 204 }
 205 EXPORT_SYMBOL_GPL(jz4740_dma_set_complete_cb);
 206
 207 void jz4740_dma_free(struct jz4740_dma_chan *dma)
 208 {
 209         dma->dev = NULL;
 210         dma->complete_cb = NULL;
 211         dma->used = 0;
 212 }
 213 EXPORT_SYMBOL_GPL(jz4740_dma_free);
 214
 215 void jz4740_dma_enable(struct jz4740_dma_chan *dma)
 216 {
 217         jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id),
 218                         JZ_DMA_STATUS_CTRL_NO_DESC | JZ_DMA_STATUS_CTRL_ENABLE,
 219                         JZ_DMA_STATUS_CTRL_HALT | JZ_DMA_STATUS_CTRL_NO_DESC |
 220                         JZ_DMA_STATUS_CTRL_ENABLE);
 221
 222         jz4740_dma_write_mask(JZ_REG_DMA_CTRL,
 223                         JZ_DMA_CTRL_ENABLE,
 224                         JZ_DMA_CTRL_HALT | JZ_DMA_CTRL_ENABLE);
 225 }
 226 EXPORT_SYMBOL_GPL(jz4740_dma_enable);
 227
 228 void jz4740_dma_disable(struct jz4740_dma_chan *dma)
 229 {
 230         jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id), 0,
 231                         JZ_DMA_STATUS_CTRL_ENABLE);
 232 }
 233 EXPORT_SYMBOL_GPL(jz4740_dma_disable);
 234
 235 uint32_t jz4740_dma_get_residue(const struct jz4740_dma_chan *dma)
 236 {
 237         uint32_t residue;
 238         residue = jz4740_dma_read(JZ_REG_DMA_TRANSFER_COUNT(dma->id));
 239         return residue << dma->transfer_shift;
 240 }
 241 EXPORT_SYMBOL_GPL(jz4740_dma_get_residue);
 242
 243 static void jz4740_dma_chan_irq(struct jz4740_dma_chan *dma)
 244 {
 245         uint32_t status;
 246
 247         status = jz4740_dma_read(JZ_REG_DMA_STATUS_CTRL(dma->id));
 248
 249         jz4740_dma_write_mask(JZ_REG_DMA_STATUS_CTRL(dma->id), 0,
 250                 JZ_DMA_STATUS_CTRL_ENABLE | JZ_DMA_STATUS_CTRL_TRANSFER_DONE);
 251
 252         if (dma->complete_cb)
 253                 dma->complete_cb(dma, 0, dma->dev);
 254 }
 255
 256 static irqreturn_t jz4740_dma_irq(int irq, void *dev_id)
 257 {
 258         uint32_t irq_status;
 259         unsigned int i;
 260
 261         irq_status = readl(jz4740_dma_base + JZ_REG_DMA_IRQ);
 262
 263         for (i = 0; i < 6; ++i) {
 264                 if (irq_status & (1 << i))
 265                         jz4740_dma_chan_irq(&jz4740_dma_channels[i]);
 266         }
 267
 268         return IRQ_HANDLED;
 269 }
 270
 271 static int jz4740_dma_init(void)
 272 {
 273         unsigned int ret;
 274
 275         jz4740_dma_base = ioremap(JZ4740_DMAC_BASE_ADDR, 0x400);
 276
 277         if (!jz4740_dma_base)
 278                 return -EBUSY;
 279
 280         spin_lock_init(&jz4740_dma_lock);
 281
 282         ret = request_irq(JZ4740_IRQ_DMAC, jz4740_dma_irq, 0, "DMA", NULL);
 283
 284         if (ret)
 285                 printk(KERN_ERR "JZ4740 DMA: Failed to request irq: %d\n", ret);
 286
 287         return ret;
 288 }
 289 arch_initcall(jz4740_dma_init);