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 }; 346