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          (1 << 4) /* DMA stop */
  21 #define DMA_ORDER_START         (1 << 3) /* DMA start */
  22 #define DMA_ORDER_ASK_VALID     (1 << 2) /* DMA ask valid flag */
  23 #define DMA_ORDER_AXI_UNCO      (1 << 1) /* Uncache access */
  24 #define DMA_ORDER_ADDR_64       (1 << 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         int ret = 0;
  99
 100         switch (cmd) {
 101         case SNDRV_PCM_TRIGGER_START:
 102         case SNDRV_PCM_TRIGGER_RESUME:
 103         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 104                 val = prtd->dma_pos_desc_phy & DMA_ORDER_ASK_MASK;
 105                 if (dev->coherent_dma_mask == DMA_BIT_MASK(64))
 106                         val |= DMA_ORDER_ADDR_64;
 107                 else
 108                         val &= ~DMA_ORDER_ADDR_64;
 109                 val |= (readq(order_reg) & DMA_ORDER_CTRL_MASK);
 110                 val |= DMA_ORDER_START;
 111                 writeq(val, order_reg);
 112
 113                 while ((readl(order_reg) & DMA_ORDER_START))
 114                         udelay(2);
 115                 break;
 116         case SNDRV_PCM_TRIGGER_STOP:
 117         case SNDRV_PCM_TRIGGER_SUSPEND:
 118         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 119                 dma_desc_save(prtd);
 120
 121                 /* dma stop */
 122                 val = readq(order_reg) | DMA_ORDER_STOP;
 123                 writeq(val, order_reg);
 124                 udelay(1000);
 125
 126                 break;
 127         default:
 128                 dev_err(dev, "Invalid pcm trigger operation\n");
 129                 return -EINVAL;
 130         }
 131
 132         return ret;
 133 }
 134
 135 static int loongson_pcm_hw_params(struct snd_soc_component *component,
 136                                   struct snd_pcm_substream *substream,
 137                                   struct snd_pcm_hw_params *params)
 138 {
 139         struct snd_pcm_runtime *runtime = substream->runtime;
 140         struct device *dev = substream->pcm->card->dev;
 141         struct loongson_runtime_data *prtd = runtime->private_data;
 142         size_t buf_len = params_buffer_bytes(params);
 143         size_t period_len = params_period_bytes(params);
 144         dma_addr_t order_addr, mem_addr;
 145         struct loongson_dma_desc *desc;
 146         u32 num_periods;
 147         int i;
 148
 149         if (buf_len % period_len) {
 150                 dev_err(dev, "buf len not multiply of period len\n");
 151                 return -EINVAL;
 152         }
 153
 154         num_periods = buf_len / period_len;
 155         if (!num_periods || num_periods > prtd->dma_desc_arr_size) {
 156                 dev_err(dev, "dma data too small or too big\n");
 157                 return -EINVAL;
 158         }
 159
 160         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 161         runtime->dma_bytes = buf_len;
 162
 163         /* initialize dma descriptor array */
 164         mem_addr = runtime->dma_addr;
 165         order_addr = prtd->dma_desc_arr_phy;
 166         for (i = 0; i < num_periods; i++) {
 167                 desc = &prtd->dma_desc_arr[i];
 168
 169                 /* next descriptor physical address */
 170                 order_addr += sizeof(*desc);
 171                 desc->order = lower_32_bits(order_addr | BIT(0));
 172                 desc->order_hi = upper_32_bits(order_addr);
 173
 174                 desc->saddr = lower_32_bits(mem_addr);
 175                 desc->saddr_hi = upper_32_bits(mem_addr);
 176                 desc->daddr = prtd->dma_data->dev_addr;
 177
 178                 desc->cmd = BIT(0);
 179                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 180                         desc->cmd |= BIT(12);
 181
 182                 desc->length = period_len >> 2;
 183                 desc->step_length = 0;
 184                 desc->step_times = 1;
 185
 186                 mem_addr += period_len;
 187         }
 188         desc = &prtd->dma_desc_arr[num_periods - 1];
 189         desc->order = lower_32_bits(prtd->dma_desc_arr_phy | BIT(0));
 190         desc->order_hi = upper_32_bits(prtd->dma_desc_arr_phy);
 191
 192         /* init position descriptor */
 193         *prtd->dma_pos_desc = *prtd->dma_desc_arr;
 194
 195         return 0;
 196 }
 197
 198 static snd_pcm_uframes_t
 199 loongson_pcm_pointer(struct snd_soc_component *component,
 200                      struct snd_pcm_substream *substream)
 201 {
 202         struct snd_pcm_runtime *runtime = substream->runtime;
 203         struct loongson_runtime_data *prtd = runtime->private_data;
 204         struct loongson_dma_desc *desc;
 205         snd_pcm_uframes_t x;
 206         u64 addr;
 207
 208         desc = dma_desc_save(prtd);
 209         addr = ((u64)desc->saddr_hi << 32) | desc->saddr;
 210
 211         x = bytes_to_frames(runtime, addr - runtime->dma_addr);
 212         if (x == runtime->buffer_size)
 213                 x = 0;
 214         return x;
 215 }
 216
 217 static irqreturn_t loongson_pcm_dma_irq(int irq, void *devid)
 218 {
 219         struct snd_pcm_substream *substream = devid;
 220
 221         snd_pcm_period_elapsed(substream);
 222         return IRQ_HANDLED;
 223 }
 224
 225 static int loongson_pcm_open(struct snd_soc_component *component,
 226                              struct snd_pcm_substream *substream)
 227 {
 228         struct snd_pcm_runtime *runtime = substream->runtime;
 229         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 230         struct snd_card *card = substream->pcm->card;
 231         struct loongson_runtime_data *prtd;
 232         struct loongson_dma_data *dma_data;
 233         int ret;
 234
 235         /*
 236          * For mysterious reasons (and despite what the manual says)
 237          * playback samples are lost if the DMA count is not a multiple
 238          * of the DMA burst size.  Let's add a rule to enforce that.
 239          */
 240         snd_pcm_hw_constraint_step(runtime, 0,
 241                                    SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
 242         snd_pcm_hw_constraint_step(runtime, 0,
 243                                    SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 128);
 244         snd_pcm_hw_constraint_integer(substream->runtime,
 245                                       SNDRV_PCM_HW_PARAM_PERIODS);
 246         snd_soc_set_runtime_hwparams(substream, &ls_pcm_hardware);
 247
 248         prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
 249         if (!prtd)
 250                 return -ENOMEM;
 251
 252         prtd->dma_desc_arr = dma_alloc_coherent(card->dev, PAGE_SIZE,
 253                                                 &prtd->dma_desc_arr_phy,
 254                                                 GFP_KERNEL);
 255         if (!prtd->dma_desc_arr) {
 256                 ret = -ENOMEM;
 257                 goto desc_err;
 258         }
 259         prtd->dma_desc_arr_size = PAGE_SIZE / sizeof(*prtd->dma_desc_arr);
 260
 261         prtd->dma_pos_desc = dma_alloc_coherent(card->dev,
 262                                                 sizeof(*prtd->dma_pos_desc),
 263                                                 &prtd->dma_pos_desc_phy,
 264                                                 GFP_KERNEL);
 265         if (!prtd->dma_pos_desc) {
 266                 ret = -ENOMEM;
 267                 goto pos_err;
 268         }
 269
 270         dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
 271         prtd->dma_data = dma_data;
 272
 273         substream->runtime->private_data = prtd;
 274
 275         return 0;
 276 pos_err:
 277         dma_free_coherent(card->dev, PAGE_SIZE, prtd->dma_desc_arr,
 278                           prtd->dma_desc_arr_phy);
 279 desc_err:
 280         kfree(prtd);
 281
 282         return ret;
 283 }
 284
 285 static int loongson_pcm_close(struct snd_soc_component *component,
 286                               struct snd_pcm_substream *substream)
 287 {
 288         struct snd_card *card = substream->pcm->card;
 289         struct loongson_runtime_data *prtd = substream->runtime->private_data;
 290
 291         dma_free_coherent(card->dev, PAGE_SIZE, prtd->dma_desc_arr,
 292                           prtd->dma_desc_arr_phy);
 293
 294         dma_free_coherent(card->dev, sizeof(*prtd->dma_pos_desc),
 295                           prtd->dma_pos_desc, prtd->dma_pos_desc_phy);
 296
 297         kfree(prtd);
 298         return 0;
 299 }
 300
 301 static int loongson_pcm_mmap(struct snd_soc_component *component,
 302                              struct snd_pcm_substream *substream,
 303                              struct vm_area_struct *vma)
 304 {
 305         return remap_pfn_range(vma, vma->vm_start,
 306                         substream->dma_buffer.addr >> PAGE_SHIFT,
 307                         vma->vm_end - vma->vm_start, vma->vm_page_prot);
 308 }
 309
 310 static int loongson_pcm_new(struct snd_soc_component *component,
 311                             struct snd_soc_pcm_runtime *rtd)
 312 {
 313         struct snd_card *card = rtd->card->snd_card;
 314         struct snd_pcm_substream *substream;
 315         struct loongson_dma_data *dma_data;
 316         unsigned int i;
 317         int ret;
 318
 319         for_each_pcm_streams(i) {
 320                 substream = rtd->pcm->streams[i].substream;
 321                 if (!substream)
 322                         continue;
 323
 324                 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0),
 325                                                     substream);
 326                 ret = devm_request_irq(card->dev, dma_data->irq,
 327                                        loongson_pcm_dma_irq,
 328                                        IRQF_TRIGGER_HIGH, LS_I2S_DRVNAME,
 329                                        substream);
 330                 if (ret < 0) {
 331                         dev_err(card->dev, "request irq for DMA failed\n");
 332                         return ret;
 333                 }
 334         }
 335
 336         return snd_pcm_set_fixed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
 337                                             card->dev,
 338                                             ls_pcm_hardware.buffer_bytes_max);
 339 }
 340
 341 const struct snd_soc_component_driver loongson_i2s_component = {
 342         .name           = LS_I2S_DRVNAME,
 343         .open           = loongson_pcm_open,
 344         .close          = loongson_pcm_close,
 345         .hw_params      = loongson_pcm_hw_params,
 346         .trigger        = loongson_pcm_trigger,
 347         .pointer        = loongson_pcm_pointer,
 348         .mmap           = loongson_pcm_mmap,
 349         .pcm_construct  = loongson_pcm_new,
 350 };