idma.c
/*
* sound/soc/samsung/idma.c
*
* Copyright (c) 2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* I2S0's Internal DMA driver
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include "i2s.h"
#include "idma.h"
#include "dma.h"
#include "i2s-regs.h"
#define ST_RUNNING (1<<0)
#define ST_OPENED (1<<1)
static const struct snd_pcm_hardware idma_hardware = {
.info = SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_PAUSE |
SNDRV_PCM_INFO_RESUME,
.buffer_bytes_max = MAX_IDMA_BUFFER,
.period_bytes_min = 128,
.period_bytes_max = MAX_IDMA_PERIOD,
.periods_min = 1,
.periods_max = 2,
};
struct idma_ctrl {
spinlock_t lock;
int state;
dma_addr_t start;
dma_addr_t pos;
dma_addr_t end;
dma_addr_t period;
dma_addr_t periodsz;
void *token;
void (*cb)(void *dt, int bytes_xfer);
};
static struct idma_info {
spinlock_t lock;
void __iomem *regs;
dma_addr_t lp_tx_addr;
} idma;
static int idma_irq;
static void idma_getpos(dma_addr_t *src)
{
*src = idma.lp_tx_addr +
(readl(idma.regs + I2STRNCNT) & 0xffffff) * 4;
}
static int idma_enqueue(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct idma_ctrl *prtd = substream->runtime->private_data;
u32 val;
spin_lock(&prtd->lock);
prtd->token = (void *) substream;
spin_unlock(&prtd->lock);
/* Internal DMA Level0 Interrupt Address */
val = idma.lp_tx_addr + prtd->periodsz;
writel(val, idma.regs + I2SLVL0ADDR);
/* Start address0 of I2S internal DMA operation. */
val = idma.lp_tx_addr;
writel(val, idma.regs + I2SSTR0);
/*
* Transfer block size for I2S internal DMA.
* Should decide transfer size before start dma operation
*/
val = readl(idma.regs + I2SSIZE);
val &= ~(I2SSIZE_TRNMSK << I2SSIZE_SHIFT);
val |= (((runtime->dma_bytes >> 2) &
I2SSIZE_TRNMSK) << I2SSIZE_SHIFT);
writel(val, idma.regs + I2SSIZE);
val = readl(idma.regs + I2SAHB);
val |= AHB_INTENLVL0;
writel(val, idma.regs + I2SAHB);
return 0;
}
static void idma_setcallbk(struct snd_pcm_substream *substream,
void (*cb)(void *, int))
{
struct idma_ctrl *prtd = substream->runtime->private_data;
spin_lock(&prtd->lock);
prtd->cb = cb;
spin_unlock(&prtd->lock);
}
static void idma_control(int op)
{
u32 val = readl(idma.regs + I2SAHB);
spin_lock(&idma.lock);
switch (op) {
case LPAM_DMA_START:
val |= (AHB_INTENLVL0 | AHB_DMAEN);
break;
case LPAM_DMA_STOP:
val &= ~(AHB_INTENLVL0 | AHB_DMAEN);
break;
default:
spin_unlock(&idma.lock);
return;
}
writel(val, idma.regs + I2SAHB);
spin_unlock(&idma.lock);
}
static void idma_done(void *id, int bytes_xfer)
{
struct snd_pcm_substream *substream = id;
struct idma_ctrl *prtd = substream->runtime->private_data;
if (prtd && (prtd->state & ST_RUNNING))
snd_pcm_period_elapsed(substream);
}
static int idma_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct idma_ctrl *prtd = substream->runtime->private_data;
u32 mod = readl(idma.regs + I2SMOD);
u32 ahb = readl(idma.regs + I2SAHB);
ahb |= (AHB_DMARLD | AHB_INTMASK);
mod |= MOD_TXS_IDMA;
writel(ahb, idma.regs + I2SAHB);
writel(mod, idma.regs + I2SMOD);
snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
runtime->dma_bytes = params_buffer_bytes(params);
prtd->start = prtd->pos = runtime->dma_addr;
prtd->period = params_periods(params);
prtd->periodsz = params_period_bytes(params);
prtd->end = runtime->dma_addr + runtime->dma_bytes;
idma_setcallbk(substream, idma_done);
return 0;
}
static int idma_hw_free(struct snd_pcm_substream *substream)
{
snd_pcm_set_runtime_buffer(substream, NULL);
return 0;
}
static int idma_prepare(struct snd_pcm_substream *substream)
{
struct idma_ctrl *prtd = substream->runtime->private_data;
prtd->pos = prtd->start;
/* flush the DMA channel */
idma_control(LPAM_DMA_STOP);
idma_enqueue(substream);
return 0;
}
static int idma_trigger(struct snd_pcm_substream *substream, int cmd)
{
struct idma_ctrl *prtd = substream->runtime->private_data;
int ret = 0;
spin_lock(&prtd->lock);
switch (cmd) {
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
prtd->state |= ST_RUNNING;
idma_control(LPAM_DMA_START);
break;
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
prtd->state &= ~ST_RUNNING;
idma_control(LPAM_DMA_STOP);
break;
default:
ret = -EINVAL;
break;
}
spin_unlock(&prtd->lock);
return ret;
}
static snd_pcm_uframes_t
idma_pointer(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct idma_ctrl *prtd = runtime->private_data;
dma_addr_t src;
unsigned long res;
spin_lock(&prtd->lock);
idma_getpos(&src);
res = src - prtd->start;
spin_unlock(&prtd->lock);
return bytes_to_frames(substream->runtime, res);
}
static int idma_mmap(struct snd_pcm_substream *substream,
struct vm_area_struct *vma)
{
struct snd_pcm_runtime *runtime = substream->runtime;
unsigned long size, offset;
int ret;
/* From snd_pcm_lib_mmap_iomem */
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
size = vma->vm_end - vma->vm_start;
offset = vma->vm_pgoff << PAGE_SHIFT;
ret = io_remap_pfn_range(vma, vma->vm_start,
(runtime->dma_addr + offset) >> PAGE_SHIFT,
size, vma->vm_page_prot);
return ret;
}
static irqreturn_t iis_irq(int irqno, void *dev_id)
{
struct idma_ctrl *prtd = (struct idma_ctrl *)dev_id;
u32 iisahb, val, addr;
iisahb = readl(idma.regs + I2SAHB);
val = (iisahb & AHB_LVL0INT) ? AHB_CLRLVL0INT : 0;
if (val) {
iisahb |= val;
writel(iisahb, idma.regs + I2SAHB);
addr = readl(idma.regs + I2SLVL0ADDR) - idma.lp_tx_addr;
addr += prtd->periodsz;
addr %= (u32)(prtd->end - prtd->start);
addr += idma.lp_tx_addr;
writel(addr, idma.regs + I2SLVL0ADDR);
if (prtd->cb)
prtd->cb(prtd->token, prtd->period);
}
return IRQ_HANDLED;
}
static int idma_open(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct idma_ctrl *prtd;
int ret;
snd_soc_set_runtime_hwparams(substream, &idma_hardware);
prtd = kzalloc(sizeof(struct idma_ctrl), GFP_KERNEL);
if (prtd == NULL)
return -ENOMEM;
ret = request_irq(idma_irq, iis_irq, 0, "i2s", prtd);
if (ret < 0) {
pr_err("fail to claim i2s irq , ret = %d\n", ret);
kfree(prtd);
return ret;
}
spin_lock_init(&prtd->lock);
runtime->private_data = prtd;
return 0;
}
static int idma_close(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct idma_ctrl *prtd = runtime->private_data;
free_irq(idma_irq, prtd);
if (!prtd)
pr_err("idma_close called with prtd == NULL\n");
kfree(prtd);
return 0;
}
static struct snd_pcm_ops idma_ops = {
.open = idma_open,
.close = idma_close,
.ioctl = snd_pcm_lib_ioctl,
.trigger = idma_trigger,
.pointer = idma_pointer,
.mmap = idma_mmap,
.hw_params = idma_hw_params,
.hw_free = idma_hw_free,
.prepare = idma_prepare,
};
static void idma_free(struct snd_pcm *pcm)
{
struct snd_pcm_substream *substream;
struct snd_dma_buffer *buf;
substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
if (!substream)
return;
buf = &substream->dma_buffer;
if (!buf->area)
return;
iounmap(buf->area);
buf->area = NULL;
buf->addr = 0;
}
static int preallocate_idma_buffer(struct snd_pcm *pcm, int stream)
{
struct snd_pcm_substream *substream = pcm->streams[stream].substream;
struct snd_dma_buffer *buf = &substream->dma_buffer;
buf->dev.dev = pcm->card->dev;
buf->private_data = NULL;
/* Assign PCM buffer pointers */
buf->dev.type = SNDRV_DMA_TYPE_CONTINUOUS;
buf->addr = idma.lp_tx_addr;
buf->bytes = idma_hardware.buffer_bytes_max;
buf->area = (unsigned char *)ioremap(buf->addr, buf->bytes);
return 0;
}
static int idma_new(struct snd_soc_pcm_runtime *rtd)
{
struct snd_card *card = rtd->card->snd_card;
struct snd_pcm *pcm = rtd->pcm;
int ret;
ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
if (ret)
return ret;
if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
ret = preallocate_idma_buffer(pcm,
SNDRV_PCM_STREAM_PLAYBACK);
}
return ret;
}
void idma_reg_addr_init(void __iomem *regs, dma_addr_t addr)
{
spin_lock_init(&idma.lock);
idma.regs = regs;
idma.lp_tx_addr = addr;
}
EXPORT_SYMBOL_GPL(idma_reg_addr_init);
static struct snd_soc_platform_driver asoc_idma_platform = {
.ops = &idma_ops,
.pcm_new = idma_new,
.pcm_free = idma_free,
};
static int asoc_idma_platform_probe(struct platform_device *pdev)
{
idma_irq = platform_get_irq(pdev, 0);
if (idma_irq < 0)
return idma_irq;
return devm_snd_soc_register_platform(&pdev->dev, &asoc_idma_platform);
}
static struct platform_driver asoc_idma_driver = {
.driver = {
.name = "samsung-idma",
.owner = THIS_MODULE,
},
.probe = asoc_idma_platform_probe,
};
module_platform_driver(asoc_idma_driver);
MODULE_AUTHOR("Jaswinder Singh, <jassisinghbrar@gmail.com>");
MODULE_DESCRIPTION("Samsung ASoC IDMA Driver");
MODULE_LICENSE("GPL");