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(asoc_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(asoc_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 }; 351