// SPDX-License-Identifier: GPL-2.0
//
// Loongson ALSA SoC Platform (DMA) driver
//
// Copyright (C) 2023 Loongson Technology Corporation Limited
// Author: Yingkun Meng <[email protected]>
//
#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 BIT(4) /* DMA stop */
#define DMA_ORDER_START BIT(3) /* DMA start */
#define DMA_ORDER_ASK_VALID BIT(2) /* DMA ask valid flag */
#define DMA_ORDER_AXI_UNCO BIT(1) /* Uncache access */
#define DMA_ORDER_ADDR_64 BIT(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;
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 0;
}
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 = snd_soc_substream_to_rtd(substream);
struct snd_card *card = substream->pcm->card;
struct loongson_runtime_data *prtd;
struct loongson_dma_data *dma_data;
/*
* 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)
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)
goto pos_err;
dma_data = snd_soc_dai_get_dma_data(snd_soc_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 -ENOMEM;
}
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(snd_soc_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,
};
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