sound/soc/loongson/loongson_dma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Loongson ALSA SoC Platform (DMA) driver
   4 //
   5 // Copyright (C) 2023 Loongson Technology Corporation Limited
   6 // Author: Yingkun Meng <mengyingkun@loongson.cn>
   7 //
   8
   9 #include <linux/module.h>
  10 #include <linux/io-64-nonatomic-lo-hi.h>
  11 #include <linux/delay.h>
  12 #include <linux/pm_runtime.h>
  13 #include <linux/dma-mapping.h>
  14 #include <sound/soc.h>
  15 #include <sound/pcm.h>
  16 #include <sound/pcm_params.h>
  17 #include "loongson_i2s.h"
  18
  19 /* DMA dma_order Register */
  20 #define DMA_ORDER_STOP          BIT(4) /* DMA stop */
  21 #define DMA_ORDER_START         BIT(3) /* DMA start */
  22 #define DMA_ORDER_ASK_VALID     BIT(2) /* DMA ask valid flag */
  23 #define DMA_ORDER_AXI_UNCO      BIT(1) /* Uncache access */
  24 #define DMA_ORDER_ADDR_64       BIT(0) /* 64bits address support */
  25
  26 #define DMA_ORDER_ASK_MASK      (~0x1fUL) /* Ask addr mask */
  27 #define DMA_ORDER_CTRL_MASK     (0x0fUL)  /* Control mask  */
  28
  29 /*
  30  * DMA registers descriptor.
  31  */
  32 struct loongson_dma_desc {
  33         u32 order;              /* Next descriptor address register */
  34         u32 saddr;              /* Source address register */
  35         u32 daddr;              /* Device address register */
  36         u32 length;             /* Total length register */
  37         u32 step_length;        /* Memory stride register */
  38         u32 step_times;         /* Repeat time register */
  39         u32 cmd;                /* Command register */
  40         u32 stats;              /* Status register */
  41         u32 order_hi;           /* Next descriptor high address register */
  42         u32 saddr_hi;           /* High source address register */
  43         u32 res[6];             /* Reserved */
  44 } __packed;
  45
  46 struct loongson_runtime_data {
  47         struct loongson_dma_data *dma_data;
  48
  49         struct loongson_dma_desc *dma_desc_arr;
  50         dma_addr_t dma_desc_arr_phy;
  51         int dma_desc_arr_size;
  52
  53         struct loongson_dma_desc *dma_pos_desc;
  54         dma_addr_t dma_pos_desc_phy;
  55 };
  56
  57 static const struct snd_pcm_hardware ls_pcm_hardware = {
  58         .info = SNDRV_PCM_INFO_MMAP |
  59                 SNDRV_PCM_INFO_INTERLEAVED |
  60                 SNDRV_PCM_INFO_MMAP_VALID |
  61                 SNDRV_PCM_INFO_RESUME |
  62                 SNDRV_PCM_INFO_PAUSE,
  63         .formats = (SNDRV_PCM_FMTBIT_S8 |
  64                 SNDRV_PCM_FMTBIT_S16_LE |
  65                 SNDRV_PCM_FMTBIT_S20_3LE |
  66                 SNDRV_PCM_FMTBIT_S24_LE),
  67         .period_bytes_min = 128,
  68         .period_bytes_max = 128 * 1024,
  69         .periods_min = 1,
  70         .periods_max = PAGE_SIZE / sizeof(struct loongson_dma_desc),
  71         .buffer_bytes_max = 1024 * 1024,
  72 };
  73
  74 static struct
  75 loongson_dma_desc *dma_desc_save(struct loongson_runtime_data *prtd)
  76 {
  77         void __iomem *order_reg = prtd->dma_data->order_addr;
  78         u64 val;
  79
  80         val = (u64)prtd->dma_pos_desc_phy & DMA_ORDER_ASK_MASK;
  81         val |= (readq(order_reg) & DMA_ORDER_CTRL_MASK);
  82         val |= DMA_ORDER_ASK_VALID;
  83         writeq(val, order_reg);
  84
  85         while (readl(order_reg) & DMA_ORDER_ASK_VALID)
  86                 udelay(2);
  87
  88         return prtd->dma_pos_desc;
  89 }
  90
  91 static int loongson_pcm_trigger(struct snd_soc_component *component,
  92                                 struct snd_pcm_substream *substream, int cmd)
  93 {
  94         struct loongson_runtime_data *prtd = substream->runtime->private_data;
  95         struct device *dev = substream->pcm->card->dev;
  96         void __iomem *order_reg = prtd->dma_data->order_addr;
  97         u64 val;
  98
  99         switch (cmd) {
 100         case SNDRV_PCM_TRIGGER_START:
 101         case SNDRV_PCM_TRIGGER_RESUME:
 102         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 103                 val = prtd->dma_pos_desc_phy & DMA_ORDER_ASK_MASK;
 104                 if (dev->coherent_dma_mask == DMA_BIT_MASK(64))
 105                         val |= DMA_ORDER_ADDR_64;
 106                 else
 107                         val &= ~DMA_ORDER_ADDR_64;
 108                 val |= (readq(order_reg) & DMA_ORDER_CTRL_MASK);
 109                 val |= DMA_ORDER_START;
 110                 writeq(val, order_reg);
 111
 112                 while ((readl(order_reg) & DMA_ORDER_START))
 113                         udelay(2);
 114                 break;
 115         case SNDRV_PCM_TRIGGER_STOP:
 116         case SNDRV_PCM_TRIGGER_SUSPEND:
 117         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 118                 dma_desc_save(prtd);
 119
 120                 /* dma stop */
 121                 val = readq(order_reg) | DMA_ORDER_STOP;
 122                 writeq(val, order_reg);
 123                 udelay(1000);
 124
 125                 break;
 126         default:
 127                 dev_err(dev, "Invalid pcm trigger operation\n");
 128                 return -EINVAL;
 129         }
 130
 131         return 0;
 132 }
 133
 134 static int loongson_pcm_hw_params(struct snd_soc_component *component,
 135                                   struct snd_pcm_substream *substream,
 136                                   struct snd_pcm_hw_params *params)
 137 {
 138         struct snd_pcm_runtime *runtime = substream->runtime;
 139         struct device *dev = substream->pcm->card->dev;
 140         struct loongson_runtime_data *prtd = runtime->private_data;
 141         size_t buf_len = params_buffer_bytes(params);
 142         size_t period_len = params_period_bytes(params);
 143         dma_addr_t order_addr, mem_addr;
 144         struct loongson_dma_desc *desc;
 145         u32 num_periods;
 146         int i;
 147
 148         if (buf_len % period_len) {
 149                 dev_err(dev, "buf len not multiply of period len\n");
 150                 return -EINVAL;
 151         }
 152
 153         num_periods = buf_len / period_len;
 154         if (!num_periods || num_periods > prtd->dma_desc_arr_size) {
 155                 dev_err(dev, "dma data too small or too big\n");
 156                 return -EINVAL;
 157         }
 158
 159         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 160         runtime->dma_bytes = buf_len;
 161
 162         /* initialize dma descriptor array */
 163         mem_addr = runtime->dma_addr;
 164         order_addr = prtd->dma_desc_arr_phy;
 165         for (i = 0; i < num_periods; i++) {
 166                 desc = &prtd->dma_desc_arr[i];
 167
 168                 /* next descriptor physical address */
 169                 order_addr += sizeof(*desc);
 170                 desc->order = lower_32_bits(order_addr | BIT(0));
 171                 desc->order_hi = upper_32_bits(order_addr);
 172
 173                 desc->saddr = lower_32_bits(mem_addr);
 174                 desc->saddr_hi = upper_32_bits(mem_addr);
 175                 desc->daddr = prtd->dma_data->dev_addr;
 176
 177                 desc->cmd = BIT(0);
 178                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 179                         desc->cmd |= BIT(12);
 180
 181                 desc->length = period_len >> 2;
 182                 desc->step_length = 0;
 183                 desc->step_times = 1;
 184
 185                 mem_addr += period_len;
 186         }
 187         desc = &prtd->dma_desc_arr[num_periods - 1];
 188         desc->order = lower_32_bits(prtd->dma_desc_arr_phy | BIT(0));
 189         desc->order_hi = upper_32_bits(prtd->dma_desc_arr_phy);
 190
 191         /* init position descriptor */
 192         *prtd->dma_pos_desc = *prtd->dma_desc_arr;
 193
 194         return 0;
 195 }
 196
 197 static snd_pcm_uframes_t
 198 loongson_pcm_pointer(struct snd_soc_component *component,
 199                      struct snd_pcm_substream *substream)
 200 {
 201         struct snd_pcm_runtime *runtime = substream->runtime;
 202         struct loongson_runtime_data *prtd = runtime->private_data;
 203         struct loongson_dma_desc *desc;
 204         snd_pcm_uframes_t x;
 205         u64 addr;
 206
 207         desc = dma_desc_save(prtd);
 208         addr = ((u64)desc->saddr_hi << 32) | desc->saddr;
 209
 210         x = bytes_to_frames(runtime, addr - runtime->dma_addr);
 211         if (x == runtime->buffer_size)
 212                 x = 0;
 213         return x;
 214 }
 215
 216 static irqreturn_t loongson_pcm_dma_irq(int irq, void *devid)
 217 {
 218         struct snd_pcm_substream *substream = devid;
 219
 220         snd_pcm_period_elapsed(substream);
 221         return IRQ_HANDLED;
 222 }
 223
 224 static int loongson_pcm_open(struct snd_soc_component *component,
 225                              struct snd_pcm_substream *substream)
 226 {
 227         struct snd_pcm_runtime *runtime = substream->runtime;
 228         struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 229         struct snd_card *card = substream->pcm->card;
 230         struct loongson_runtime_data *prtd;
 231         struct loongson_dma_data *dma_data;
 232
 233         /*
 234          * For mysterious reasons (and despite what the manual says)
 235          * playback samples are lost if the DMA count is not a multiple
 236          * of the DMA burst size.  Let's add a rule to enforce that.
 237          */
 238         snd_pcm_hw_constraint_step(runtime, 0,
 239                                    SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
 240         snd_pcm_hw_constraint_step(runtime, 0,
 241                                    SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 128);
 242         snd_pcm_hw_constraint_integer(substream->runtime,
 243                                       SNDRV_PCM_HW_PARAM_PERIODS);
 244         snd_soc_set_runtime_hwparams(substream, &ls_pcm_hardware);
 245
 246         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 247         if (!prtd)
 248                 return -ENOMEM;
 249
 250         prtd->dma_desc_arr = dma_alloc_coherent(card->dev, PAGE_SIZE,
 251                                                 &prtd->dma_desc_arr_phy,
 252                                                 GFP_KERNEL);
 253         if (!prtd->dma_desc_arr)
 254                 goto desc_err;
 255
 256         prtd->dma_desc_arr_size = PAGE_SIZE / sizeof(*prtd->dma_desc_arr);
 257
 258         prtd->dma_pos_desc = dma_alloc_coherent(card->dev,
 259                                                 sizeof(*prtd->dma_pos_desc),
 260                                                 &prtd->dma_pos_desc_phy,
 261                                                 GFP_KERNEL);
 262         if (!prtd->dma_pos_desc)
 263                 goto pos_err;
 264
 265         dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
 266         prtd->dma_data = dma_data;
 267
 268         substream->runtime->private_data = prtd;
 269
 270         return 0;
 271 pos_err:
 272         dma_free_coherent(card->dev, PAGE_SIZE, prtd->dma_desc_arr,
 273                           prtd->dma_desc_arr_phy);
 274 desc_err:
 275         kfree(prtd);
 276
 277         return -ENOMEM;
 278 }
 279
 280 static int loongson_pcm_close(struct snd_soc_component *component,
 281                               struct snd_pcm_substream *substream)
 282 {
 283         struct snd_card *card = substream->pcm->card;
 284         struct loongson_runtime_data *prtd = substream->runtime->private_data;
 285
 286         dma_free_coherent(card->dev, PAGE_SIZE, prtd->dma_desc_arr,
 287                           prtd->dma_desc_arr_phy);
 288
 289         dma_free_coherent(card->dev, sizeof(*prtd->dma_pos_desc),
 290                           prtd->dma_pos_desc, prtd->dma_pos_desc_phy);
 291
 292         kfree(prtd);
 293         return 0;
 294 }
 295
 296 static int loongson_pcm_mmap(struct snd_soc_component *component,
 297                              struct snd_pcm_substream *substream,
 298                              struct vm_area_struct *vma)
 299 {
 300         return remap_pfn_range(vma, vma->vm_start,
 301                         substream->dma_buffer.addr >> PAGE_SHIFT,
 302                         vma->vm_end - vma->vm_start, vma->vm_page_prot);
 303 }
 304
 305 static int loongson_pcm_new(struct snd_soc_component *component,
 306                             struct snd_soc_pcm_runtime *rtd)
 307 {
 308         struct snd_card *card = rtd->card->snd_card;
 309         struct snd_pcm_substream *substream;
 310         struct loongson_dma_data *dma_data;
 311         unsigned int i;
 312         int ret;
 313
 314         for_each_pcm_streams(i) {
 315                 substream = rtd->pcm->streams[i].substream;
 316                 if (!substream)
 317                         continue;
 318
 319                 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0),
 320                                                     substream);
 321                 ret = devm_request_irq(card->dev, dma_data->irq,
 322                                        loongson_pcm_dma_irq,
 323                                        IRQF_TRIGGER_HIGH, LS_I2S_DRVNAME,
 324                                        substream);
 325                 if (ret < 0) {
 326                         dev_err(card->dev, "request irq for DMA failed\n");
 327                         return ret;
 328                 }
 329         }
 330
 331         return snd_pcm_set_fixed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
 332                                             card->dev,
 333                                             ls_pcm_hardware.buffer_bytes_max);
 334 }
 335
 336 const struct snd_soc_component_driver loongson_i2s_component = {
 337         .name           = LS_I2S_DRVNAME,
 338         .open           = loongson_pcm_open,
 339         .close          = loongson_pcm_close,
 340         .hw_params      = loongson_pcm_hw_params,
 341         .trigger        = loongson_pcm_trigger,
 342         .pointer        = loongson_pcm_pointer,
 343         .mmap           = loongson_pcm_mmap,
 344         .pcm_construct  = loongson_pcm_new,
 345 };