Re: [PATCH v4 4/4] ASoC: SAMSUNG: Add I2S0 internal dma driver

[Liam Girdwood <lrg@ti.com>]

On 01/07/11 02:48, Sangbeom Kim wrote:
> I2S in Exynos4 and S5PC110(S5PV210) has a internal dma.
> It can be used low power audio mode and 2nd channel transfer.
> This patch can support idma.
> 
> Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
> ---
>  sound/soc/samsung/Makefile |    2 +
>  sound/soc/samsung/idma.c   |  455 ++++++++++++++++++++++++++++++++++++++++++++
>  sound/soc/samsung/idma.h   |   26 +++
>  3 files changed, 483 insertions(+), 0 deletions(-)
>  create mode 100644 sound/soc/samsung/idma.c
>  create mode 100644 sound/soc/samsung/idma.h
> 
> diff --git a/sound/soc/samsung/Makefile b/sound/soc/samsung/Makefile
> index 00ba557..41becdd 100644
> --- a/sound/soc/samsung/Makefile
> +++ b/sound/soc/samsung/Makefile
> @@ -1,5 +1,6 @@
>  # S3c24XX Platform Support
>  snd-soc-s3c24xx-objs := dma.o
> +snd-soc-idma-objs := idma.o
>  snd-soc-s3c24xx-i2s-objs := s3c24xx-i2s.o
>  snd-soc-s3c2412-i2s-objs := s3c2412-i2s.o
>  snd-soc-ac97-objs := ac97.o
> @@ -16,6 +17,7 @@ obj-$(CONFIG_SND_S3C_I2SV2_SOC) += snd-soc-s3c-i2s-v2.o
>  obj-$(CONFIG_SND_SAMSUNG_SPDIF) += snd-soc-samsung-spdif.o
>  obj-$(CONFIG_SND_SAMSUNG_PCM) += snd-soc-pcm.o
>  obj-$(CONFIG_SND_SAMSUNG_I2S) += snd-soc-i2s.o
> +obj-$(CONFIG_SND_SAMSUNG_I2S) += snd-soc-idma.o
> 
>  # S3C24XX Machine Support
>  snd-soc-jive-wm8750-objs := jive_wm8750.o
> diff --git a/sound/soc/samsung/idma.c b/sound/soc/samsung/idma.c
> new file mode 100644
> index 0000000..575af05
> --- /dev/null
> +++ b/sound/soc/samsung/idma.c
> @@ -0,0 +1,455 @@
> +/*
> + * linux/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 <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,
> +       .formats = SNDRV_PCM_FMTBIT_S16_LE |
> +                   SNDRV_PCM_FMTBIT_U16_LE |
> +                   SNDRV_PCM_FMTBIT_S24_LE |
> +                   SNDRV_PCM_FMTBIT_U24_LE |
> +                   SNDRV_PCM_FMTBIT_U8 |
> +                   SNDRV_PCM_FMTBIT_S8,
> +       .channels_min = 2,
> +       .channels_max = 2,
> +       .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 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);
> +

Formatting looks funny here.

> +       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:
> +               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);
> +
> +       if (res >= snd_pcm_lib_buffer_bytes(substream))
> +               res = 0;
>

Is it likely that your DMA pointer will go beyond the buffer size ?
If this happens then I suspect you have something wrong in your DMA config ?

> +       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);
> +       vma->vm_flags |= VM_IO;
> +       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 iiscon, iisahb, val, addr;
> +
> +       iisahb  = readl(idma.regs + I2SAHB);
> +       iiscon  = readl(idma.regs + I2SCON);
> +
> +       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 %= prtd->period;
> +               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(IRQ_I2S0, 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(IRQ_I2S0, prtd);
> +
> +       if (!prtd)
> +               pr_err("idma_close called with prtd == NULL\n");

Is this required ? 

> +
> +       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 u64 idma_mask = DMA_BIT_MASK(32);
> +
> +static int idma_new(struct snd_soc_pcm_runtime *rtd)
> +{
> +       struct snd_card *card = rtd->card->snd_card;
> +       struct snd_soc_dai *dai = rtd->cpu_dai;
> +       struct snd_pcm *pcm = rtd->pcm;
> +       int ret = 0;
> +
> +       if (!card->dev->dma_mask)
> +               card->dev->dma_mask = &idma_mask;
> +       if (!card->dev->coherent_dma_mask)
> +               card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
> +
> +       if (dai->driver->playback.channels_min)
> +               ret = preallocate_idma_buffer(pcm,
> +                               SNDRV_PCM_STREAM_PLAYBACK);
> +
> +       return ret;
> +}
> +
> +void idma_reg_addr_init(void *regs, dma_addr_t addr)
> +{
> +       spin_lock_init(&idma.lock);
> +       idma.regs = regs;
> +       idma.lp_tx_addr = addr;
> +}
> +
> +struct snd_soc_platform_driver asoc_idma_platform = {
> +       .ops = &idma_ops,
> +       .pcm_new = idma_new,
> +       .pcm_free = idma_free,
> +};
> +
> +static int __devinit asoc_idma_platform_probe(struct platform_device *pdev)
> +{
> +       return snd_soc_register_platform(&pdev->dev, &asoc_idma_platform);
> +}
> +
> +static int __devexit asoc_idma_platform_remove(struct platform_device *pdev)
> +{
> +       snd_soc_unregister_platform(&pdev->dev);
> +       return 0;
> +}
> +
> +static struct platform_driver asoc_idma_driver = {
> +       .driver = {
> +               .name = "samsung-idma",
> +               .owner = THIS_MODULE,
> +       },
> +
> +       .probe = asoc_idma_platform_probe,
> +       .remove = __devexit_p(asoc_idma_platform_remove),
> +};
> +
> +static int __init asoc_idma_init(void)
> +{
> +       return platform_driver_register(&asoc_idma_driver);
> +}
> +module_init(asoc_idma_init);
> +
> +static void __exit asoc_idma_exit(void)
> +{
> +       platform_driver_unregister(&asoc_idma_driver);
> +}
> +module_exit(asoc_idma_exit);
> +
> +MODULE_AUTHOR("Jaswinder Singh, <jassisinghbrar@gmail.com>");
> +MODULE_DESCRIPTION("Samsung ASoC IDMA Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/sound/soc/samsung/idma.h b/sound/soc/samsung/idma.h
> new file mode 100644
> index 0000000..5b91749
> --- /dev/null
> +++ b/sound/soc/samsung/idma.h
> @@ -0,0 +1,26 @@
> +/*
> + * linux/sound/soc/samsung/idma.h

The path is wrong now.

> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd
> + *             http://www.samsung.com
> + *
> + *  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.
> + *
> + */
> +
> +#ifndef __SND_SOC_SAMSUNG_IDMA_H_
> +#define __SND_SOC_SAMSUNG_IDMA_H_
> +
> +extern void idma_reg_addr_init(void *regs, dma_addr_t addr);
> +
> +/* dma_state */
> +#define LPAM_DMA_STOP  0
> +#define LPAM_DMA_START 1
> +
> +#define MAX_IDMA_PERIOD (128 * 1024)
> +#define MAX_IDMA_BUFFER (160 * 1024)
> +
> +#endif /* __SND_SOC_SAMSUNG_IDMA_H_ */
> --
> 1.7.1
> 
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