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-rw-r--r--sound/soc/loongson/loongson_dma.c350
1 files changed, 350 insertions, 0 deletions
diff --git a/sound/soc/loongson/loongson_dma.c b/sound/soc/loongson/loongson_dma.c
new file mode 100644
index 0000000000..65b6719e61
--- /dev/null
+++ b/sound/soc/loongson/loongson_dma.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Loongson ALSA SoC Platform (DMA) driver
+//
+// Copyright (C) 2023 Loongson Technology Corporation Limited
+// Author: Yingkun Meng <mengyingkun@loongson.cn>
+//
+
+#include <linux/module.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/delay.h>
+#include <linux/pm_runtime.h>
+#include <linux/dma-mapping.h>
+#include <sound/soc.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include "loongson_i2s.h"
+
+/* DMA dma_order Register */
+#define DMA_ORDER_STOP (1 << 4) /* DMA stop */
+#define DMA_ORDER_START (1 << 3) /* DMA start */
+#define DMA_ORDER_ASK_VALID (1 << 2) /* DMA ask valid flag */
+#define DMA_ORDER_AXI_UNCO (1 << 1) /* Uncache access */
+#define DMA_ORDER_ADDR_64 (1 << 0) /* 64bits address support */
+
+#define DMA_ORDER_ASK_MASK (~0x1fUL) /* Ask addr mask */
+#define DMA_ORDER_CTRL_MASK (0x0fUL) /* Control mask */
+
+/*
+ * DMA registers descriptor.
+ */
+struct loongson_dma_desc {
+ u32 order; /* Next descriptor address register */
+ u32 saddr; /* Source address register */
+ u32 daddr; /* Device address register */
+ u32 length; /* Total length register */
+ u32 step_length; /* Memory stride register */
+ u32 step_times; /* Repeat time register */
+ u32 cmd; /* Command register */
+ u32 stats; /* Status register */
+ u32 order_hi; /* Next descriptor high address register */
+ u32 saddr_hi; /* High source address register */
+ u32 res[6]; /* Reserved */
+} __packed;
+
+struct loongson_runtime_data {
+ struct loongson_dma_data *dma_data;
+
+ struct loongson_dma_desc *dma_desc_arr;
+ dma_addr_t dma_desc_arr_phy;
+ int dma_desc_arr_size;
+
+ struct loongson_dma_desc *dma_pos_desc;
+ dma_addr_t dma_pos_desc_phy;
+};
+
+static const struct snd_pcm_hardware ls_pcm_hardware = {
+ .info = SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_MMAP_VALID |
+ SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_PAUSE,
+ .formats = (SNDRV_PCM_FMTBIT_S8 |
+ SNDRV_PCM_FMTBIT_S16_LE |
+ SNDRV_PCM_FMTBIT_S20_3LE |
+ SNDRV_PCM_FMTBIT_S24_LE),
+ .period_bytes_min = 128,
+ .period_bytes_max = 128 * 1024,
+ .periods_min = 1,
+ .periods_max = PAGE_SIZE / sizeof(struct loongson_dma_desc),
+ .buffer_bytes_max = 1024 * 1024,
+};
+
+static struct
+loongson_dma_desc *dma_desc_save(struct loongson_runtime_data *prtd)
+{
+ void __iomem *order_reg = prtd->dma_data->order_addr;
+ u64 val;
+
+ val = (u64)prtd->dma_pos_desc_phy & DMA_ORDER_ASK_MASK;
+ val |= (readq(order_reg) & DMA_ORDER_CTRL_MASK);
+ val |= DMA_ORDER_ASK_VALID;
+ writeq(val, order_reg);
+
+ while (readl(order_reg) & DMA_ORDER_ASK_VALID)
+ udelay(2);
+
+ return prtd->dma_pos_desc;
+}
+
+static int loongson_pcm_trigger(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream, int cmd)
+{
+ struct loongson_runtime_data *prtd = substream->runtime->private_data;
+ struct device *dev = substream->pcm->card->dev;
+ void __iomem *order_reg = prtd->dma_data->order_addr;
+ u64 val;
+ int ret = 0;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ val = prtd->dma_pos_desc_phy & DMA_ORDER_ASK_MASK;
+ if (dev->coherent_dma_mask == DMA_BIT_MASK(64))
+ val |= DMA_ORDER_ADDR_64;
+ else
+ val &= ~DMA_ORDER_ADDR_64;
+ val |= (readq(order_reg) & DMA_ORDER_CTRL_MASK);
+ val |= DMA_ORDER_START;
+ writeq(val, order_reg);
+
+ while ((readl(order_reg) & DMA_ORDER_START))
+ udelay(2);
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ dma_desc_save(prtd);
+
+ /* dma stop */
+ val = readq(order_reg) | DMA_ORDER_STOP;
+ writeq(val, order_reg);
+ udelay(1000);
+
+ break;
+ default:
+ dev_err(dev, "Invalid pcm trigger operation\n");
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int loongson_pcm_hw_params(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct device *dev = substream->pcm->card->dev;
+ struct loongson_runtime_data *prtd = runtime->private_data;
+ size_t buf_len = params_buffer_bytes(params);
+ size_t period_len = params_period_bytes(params);
+ dma_addr_t order_addr, mem_addr;
+ struct loongson_dma_desc *desc;
+ u32 num_periods;
+ int i;
+
+ if (buf_len % period_len) {
+ dev_err(dev, "buf len not multiply of period len\n");
+ return -EINVAL;
+ }
+
+ num_periods = buf_len / period_len;
+ if (!num_periods || num_periods > prtd->dma_desc_arr_size) {
+ dev_err(dev, "dma data too small or too big\n");
+ return -EINVAL;
+ }
+
+ snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+ runtime->dma_bytes = buf_len;
+
+ /* initialize dma descriptor array */
+ mem_addr = runtime->dma_addr;
+ order_addr = prtd->dma_desc_arr_phy;
+ for (i = 0; i < num_periods; i++) {
+ desc = &prtd->dma_desc_arr[i];
+
+ /* next descriptor physical address */
+ order_addr += sizeof(*desc);
+ desc->order = lower_32_bits(order_addr | BIT(0));
+ desc->order_hi = upper_32_bits(order_addr);
+
+ desc->saddr = lower_32_bits(mem_addr);
+ desc->saddr_hi = upper_32_bits(mem_addr);
+ desc->daddr = prtd->dma_data->dev_addr;
+
+ desc->cmd = BIT(0);
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ desc->cmd |= BIT(12);
+
+ desc->length = period_len >> 2;
+ desc->step_length = 0;
+ desc->step_times = 1;
+
+ mem_addr += period_len;
+ }
+ desc = &prtd->dma_desc_arr[num_periods - 1];
+ desc->order = lower_32_bits(prtd->dma_desc_arr_phy | BIT(0));
+ desc->order_hi = upper_32_bits(prtd->dma_desc_arr_phy);
+
+ /* init position descriptor */
+ *prtd->dma_pos_desc = *prtd->dma_desc_arr;
+
+ return 0;
+}
+
+static snd_pcm_uframes_t
+loongson_pcm_pointer(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct loongson_runtime_data *prtd = runtime->private_data;
+ struct loongson_dma_desc *desc;
+ snd_pcm_uframes_t x;
+ u64 addr;
+
+ desc = dma_desc_save(prtd);
+ addr = ((u64)desc->saddr_hi << 32) | desc->saddr;
+
+ x = bytes_to_frames(runtime, addr - runtime->dma_addr);
+ if (x == runtime->buffer_size)
+ x = 0;
+ return x;
+}
+
+static irqreturn_t loongson_pcm_dma_irq(int irq, void *devid)
+{
+ struct snd_pcm_substream *substream = devid;
+
+ snd_pcm_period_elapsed(substream);
+ return IRQ_HANDLED;
+}
+
+static int loongson_pcm_open(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct snd_soc_pcm_runtime *rtd = substream->private_data;
+ struct snd_card *card = substream->pcm->card;
+ struct loongson_runtime_data *prtd;
+ struct loongson_dma_data *dma_data;
+ int ret;
+
+ /*
+ * For mysterious reasons (and despite what the manual says)
+ * playback samples are lost if the DMA count is not a multiple
+ * of the DMA burst size. Let's add a rule to enforce that.
+ */
+ snd_pcm_hw_constraint_step(runtime, 0,
+ SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 128);
+ snd_pcm_hw_constraint_step(runtime, 0,
+ SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 128);
+ snd_pcm_hw_constraint_integer(substream->runtime,
+ SNDRV_PCM_HW_PARAM_PERIODS);
+ snd_soc_set_runtime_hwparams(substream, &ls_pcm_hardware);
+
+ prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
+ if (!prtd)
+ return -ENOMEM;
+
+ prtd->dma_desc_arr = dma_alloc_coherent(card->dev, PAGE_SIZE,
+ &prtd->dma_desc_arr_phy,
+ GFP_KERNEL);
+ if (!prtd->dma_desc_arr) {
+ ret = -ENOMEM;
+ goto desc_err;
+ }
+ prtd->dma_desc_arr_size = PAGE_SIZE / sizeof(*prtd->dma_desc_arr);
+
+ prtd->dma_pos_desc = dma_alloc_coherent(card->dev,
+ sizeof(*prtd->dma_pos_desc),
+ &prtd->dma_pos_desc_phy,
+ GFP_KERNEL);
+ if (!prtd->dma_pos_desc) {
+ ret = -ENOMEM;
+ goto pos_err;
+ }
+
+ dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
+ prtd->dma_data = dma_data;
+
+ substream->runtime->private_data = prtd;
+
+ return 0;
+pos_err:
+ dma_free_coherent(card->dev, PAGE_SIZE, prtd->dma_desc_arr,
+ prtd->dma_desc_arr_phy);
+desc_err:
+ kfree(prtd);
+
+ return ret;
+}
+
+static int loongson_pcm_close(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream)
+{
+ struct snd_card *card = substream->pcm->card;
+ struct loongson_runtime_data *prtd = substream->runtime->private_data;
+
+ dma_free_coherent(card->dev, PAGE_SIZE, prtd->dma_desc_arr,
+ prtd->dma_desc_arr_phy);
+
+ dma_free_coherent(card->dev, sizeof(*prtd->dma_pos_desc),
+ prtd->dma_pos_desc, prtd->dma_pos_desc_phy);
+
+ kfree(prtd);
+ return 0;
+}
+
+static int loongson_pcm_mmap(struct snd_soc_component *component,
+ struct snd_pcm_substream *substream,
+ struct vm_area_struct *vma)
+{
+ return remap_pfn_range(vma, vma->vm_start,
+ substream->dma_buffer.addr >> PAGE_SHIFT,
+ vma->vm_end - vma->vm_start, vma->vm_page_prot);
+}
+
+static int loongson_pcm_new(struct snd_soc_component *component,
+ struct snd_soc_pcm_runtime *rtd)
+{
+ struct snd_card *card = rtd->card->snd_card;
+ struct snd_pcm_substream *substream;
+ struct loongson_dma_data *dma_data;
+ unsigned int i;
+ int ret;
+
+ for_each_pcm_streams(i) {
+ substream = rtd->pcm->streams[i].substream;
+ if (!substream)
+ continue;
+
+ dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0),
+ substream);
+ ret = devm_request_irq(card->dev, dma_data->irq,
+ loongson_pcm_dma_irq,
+ IRQF_TRIGGER_HIGH, LS_I2S_DRVNAME,
+ substream);
+ if (ret < 0) {
+ dev_err(card->dev, "request irq for DMA failed\n");
+ return ret;
+ }
+ }
+
+ return snd_pcm_set_fixed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
+ card->dev,
+ ls_pcm_hardware.buffer_bytes_max);
+}
+
+const struct snd_soc_component_driver loongson_i2s_component = {
+ .name = LS_I2S_DRVNAME,
+ .open = loongson_pcm_open,
+ .close = loongson_pcm_close,
+ .hw_params = loongson_pcm_hw_params,
+ .trigger = loongson_pcm_trigger,
+ .pointer = loongson_pcm_pointer,
+ .mmap = loongson_pcm_mmap,
+ .pcm_construct = loongson_pcm_new,
+};