arch/arm/mach-moxart/apb_dma.c

   1 /* Copyright (C) 2013 Jonas Jensen <jonas.jensen@gmail.com>
   2  * This program is free software; you can redistribute it and/or modify it
   3  * under the terms of the GNU General Public License as published by the
   4  * Free Software Foundation; either version 2 of the License,
   5  * or (at your option) any later version. */
   6
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/io.h>
  10 #include <linux/irq.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/interrupt.h>
  13
  14 #include <asm/cacheflush.h>
  15
  16 #include <mach/hardware.h>
  17 #include <mach/irqs.h>
  18 #include <mach/apb_dma.h>
  19
  20 static struct apb_dma_priv      apb_dma_channel[APB_DMA_MAX_CHANNEL];
  21 static spinlock_t apb_dma_lock;
  22
  23 struct apb_dma_priv *apb_dma_alloc(int req_no)
  24 {
  25         int i;
  26         unsigned long flags;
  27         struct apb_dma_priv *priv = apb_dma_channel;
  28
  29         spin_lock_irqsave(&apb_dma_lock, flags);
  30         for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, priv++) {
  31                 if (priv->used_flag == 0) {
  32                         priv->used_flag = 1;
  33                         priv->irq_handler = NULL;
  34                         priv->irq_handler_param = NULL;
  35                         priv->error_flag = 0;
  36                         priv->req_no = req_no;
  37                         switch (req_no) {
  38                         case APB_DMA_SD_REQ_NO:
  39                                 *(unsigned int *) (IO_ADDRESS(MOXART_PMU_BASE)
  40                                         + 0xB8) = 0;
  41                                 break;
  42                         }
  43                         spin_unlock_irqrestore(&apb_dma_lock, flags);
  44                         dbg_printk(KERN_INFO
  45                         "MOXART APB DMA: apb_dma_alloc uses DMA channel %d\n"
  46                         , i);
  47                         return priv;
  48                 }
  49         }
  50         spin_unlock_irqrestore(&apb_dma_lock, flags);
  51         return NULL;
  52 }
  53
  54 void apb_dma_release(struct apb_dma_priv *priv)
  55 {
  56         unsigned long flags;
  57
  58         spin_lock_irqsave(&apb_dma_lock, flags);
  59         if (priv == NULL) {
  60                 spin_unlock_irqrestore(&apb_dma_lock, flags);
  61                 return;
  62         }
  63         priv->used_flag = 0;
  64         priv->error_flag = 0;
  65         priv->irq_handler = NULL;
  66         priv->irq_handler_param = NULL;
  67         priv->req_no = 0;
  68         spin_unlock_irqrestore(&apb_dma_lock, flags);
  69 }
  70
  71 void apb_dma_set_irq(struct apb_dma_priv *priv,
  72         void (*func)(void *param), void *param)
  73 {
  74         unsigned long flags;
  75         unsigned int cmd;
  76
  77         spin_lock_irqsave(&apb_dma_lock, flags);
  78         if (priv == NULL) {
  79                 spin_unlock_irqrestore(&apb_dma_lock, flags);
  80                 return;
  81         }
  82         priv->irq_handler = func;
  83         priv->irq_handler_param = param;
  84         priv->error_flag = 0;
  85         cmd = readl(&priv->reg->command.ul);
  86         cmd |= (APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
  87         writel(cmd, &priv->reg->command.ul);
  88         spin_unlock_irqrestore(&apb_dma_lock, flags);
  89 }
  90
  91 void apb_dma_release_irq(struct apb_dma_priv *priv)
  92 {
  93         unsigned long flags;
  94         unsigned int cmd;
  95
  96         spin_lock_irqsave(&apb_dma_lock, flags);
  97         if (priv == NULL) {
  98                 spin_unlock_irqrestore(&apb_dma_lock, flags);
  99                 return;
 100         }
 101         cmd = readl(&priv->reg->command.ul);
 102         cmd &= ~(APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);
 103         writel(cmd, &priv->reg->command.ul);
 104         priv->irq_handler = NULL;
 105         priv->irq_handler_param = NULL;
 106         priv->error_flag = 0;
 107         spin_unlock_irqrestore(&apb_dma_lock, flags);
 108 }
 109
 110 void apb_dma_conf(struct apb_dma_priv *priv, struct apb_dma_conf_param *param)
 111 {
 112         unsigned long flags;
 113         union _command cmd;
 114         unsigned int size;
 115
 116         spin_lock_irqsave(&apb_dma_lock, flags);
 117
 118         if (param->source_sel == APB_DMAB_SOURCE_AHB) {
 119                 writel(virt_to_phys((void *)param->source_addr),
 120                         &priv->reg->source_addr);
 121         } else
 122                 writel(PHY_ADDRESS(param->source_addr),
 123                         &priv->reg->source_addr);
 124
 125         if (param->dest_sel == APB_DMAB_DEST_AHB) {
 126                 writel(virt_to_phys((void *)param->dest_addr),
 127                         &priv->reg->dest_addr);
 128         } else
 129                 writel(PHY_ADDRESS(param->dest_addr), &priv->reg->dest_addr);
 130
 131         size = param->size;
 132         switch (param->data_width) {
 133         case APB_DMAB_DATA_WIDTH_1:
 134                 break;
 135         case APB_DMAB_DATA_WIDTH_2:
 136                 size >>= 1;
 137                 break;
 138         case APB_DMAB_DATA_WIDTH_4:
 139         default:
 140                 size >>= 2;
 141                 break;
 142         }
 143
 144         if (param->burst_mode)
 145                 size >>= 2;
 146
 147         writel(size, &priv->reg->cycles);
 148         cmd.ul = readl(&priv->reg->command.ul);
 149         cmd.bits.data_width = param->data_width;
 150         if (param->dest_sel) { /* AHB */
 151                 dmac_inv_range((void *)param->dest_addr,
 152                         (void *)param->dest_addr + param->size);
 153                 cmd.bits.dest_req_no = 0;
 154         } else { /* APB */
 155                 cmd.bits.dest_req_no = priv->req_no;
 156         }
 157         cmd.bits.dest_sel = param->dest_sel;
 158         if (param->source_sel) { /* AHB */
 159                 dmac_flush_range((void *)param->source_addr,
 160                         (void *)param->source_addr + param->size);
 161                 cmd.bits.source_req_no = 0;
 162         } else { /* APB */
 163                 cmd.bits.source_req_no = priv->req_no;
 164         }
 165         cmd.bits.source_sel = param->source_sel;
 166         cmd.bits.burst = param->burst_mode;
 167         cmd.bits.dest_inc = param->dest_inc;
 168         cmd.bits.source_inc = param->source_inc;
 169         writel(cmd.ul, &priv->reg->command.ul);
 170
 171         cmd.ul = readl(&priv->reg->command.ul);
 172         dbg_printk(KERN_INFO
 173                 "apb_dma_conf: cmd.ul=%x read from &priv->reg->command.ul=%x\n"
 174                 , cmd.ul, (unsigned int)&priv->reg->command.ul);
 175
 176         spin_unlock_irqrestore(&apb_dma_lock, flags);
 177 }
 178
 179 void apb_dma_enable(struct apb_dma_priv *priv)
 180 {
 181         unsigned long flags;
 182         unsigned int cmd;
 183
 184         spin_lock_irqsave(&apb_dma_lock, flags);
 185         cmd = readl(&priv->reg->command.ul);
 186         /* dbg_printk(KERN_INFO "apb_dma_enable: cmd=%x read from
 187                 "&priv->reg->command.ul=%x\n", cmd,
 188                 (unsigned int)&priv->reg->command.ul);*/
 189         cmd |= APB_DMA_ENABLE;
 190         writel(cmd, &priv->reg->command.ul);
 191         cmd = readl(&priv->reg->command.ul);
 192         /* dbg_printk(KERN_INFO "apb_dma_enable: readback:"
 193                 "(cmd | APB_DMA_ENABLE)=%x\n", cmd);*/
 194         spin_unlock_irqrestore(&apb_dma_lock, flags);
 195 }
 196
 197 void apb_dma_disable(struct apb_dma_priv *priv)
 198 {
 199         unsigned long flags;
 200         unsigned int cmd;
 201
 202         spin_lock_irqsave(&apb_dma_lock, flags);
 203         cmd = readl(&priv->reg->command.ul);
 204         cmd &= ~APB_DMA_ENABLE;
 205         writel(cmd, &priv->reg->command.ul);
 206         spin_unlock_irqrestore(&apb_dma_lock, flags);
 207 }
 208
 209 static irqreturn_t moxart_dma_interrupt(int irq, void *devid)
 210 {
 211         int i;
 212         unsigned int cmd;
 213         struct apb_dma_priv *priv = apb_dma_channel;
 214
 215         /* dbg_printk(KERN_INFO "moxart_dma_interrupt\n"); */
 216         for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, priv++) {
 217                 cmd = readl(&priv->reg->command.ul);
 218                 if (cmd & APB_DMA_FIN_INT_STS)
 219                         cmd &= ~APB_DMA_FIN_INT_STS;
 220                 if (cmd & APB_DMA_ERR_INT_STS) {
 221                         cmd &= ~APB_DMA_ERR_INT_STS;
 222                         priv->error_flag = 1;
 223                 }
 224                 if (priv->used_flag && priv->irq_handler)
 225                         priv->irq_handler(priv->irq_handler_param);
 226                 priv->error_flag = 0;
 227                 writel(cmd, &priv->reg->command.ul);
 228         }
 229
 230         return IRQ_HANDLED;
 231 }
 232
 233 static struct irqaction moxart_dma_irq = {
 234         .name           = "MOXART APB DMA",
 235         .flags          = IRQF_DISABLED,
 236         .handler        = moxart_dma_interrupt,
 237 };
 238
 239 static int moxart_dma_probe(struct platform_device *pdev)
 240 {
 241         int i;
 242         struct apb_dma_priv *priv = apb_dma_channel;
 243
 244         memset(apb_dma_channel, 0, sizeof(apb_dma_channel));
 245         spin_lock_init(&apb_dma_lock);
 246
 247         for (i = 0; i < APB_DMA_MAX_CHANNEL; i++)
 248                 priv[i].reg = (struct apb_dma_reg *)
 249                         (IO_ADDRESS(MOXART_APB_DMA_BASE)
 250                         + 0x80 + i*sizeof(struct apb_dma_reg));
 251
 252         moxart_int_set_irq(IRQ_APB_DMA, EDGE, H_ACTIVE);
 253         setup_irq(IRQ_APB_DMA, &moxart_dma_irq);
 254
 255         dev_info(&pdev->dev, "MOXART APB DMA: finished moxart_dma_probe\n");
 256
 257         return 0;
 258 }
 259
 260 static int moxart_dma_remove(struct platform_device *pdev)
 261 {
 262         return 0;
 263 }
 264
 265 static struct platform_driver moxart_dma_driver = {
 266         .probe          = moxart_dma_probe,
 267         .remove         = __devexit_p(moxart_dma_remove),
 268         .driver         = {
 269                 .name   = "MOXART_APB_DMA",
 270                 .owner  = THIS_MODULE,
 271         },
 272 };
 273
 274 static __init int moxart_init(void)
 275 {
 276         return platform_driver_register(&moxart_dma_driver);
 277 }
 278
 279 static __exit void moxart_exit(void)
 280 {
 281         platform_driver_unregister(&moxart_dma_driver);
 282 }
 283
 284 module_init(moxart_init);
 285 module_exit(moxart_exit);
 286
 287 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
 288 MODULE_DESCRIPTION("MOXART APB DMA driver");
 289 MODULE_LICENSE("GPL");
 290 MODULE_VERSION(DRV_VERSION);