cregit-Linux how code gets into the kernel

Release 4.7 sound/soc/sh/dma-sh7760.c

Directory: sound/soc/sh
/*
 * SH7760 ("camelot") DMABRG audio DMA unit support
 *
 * Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net>
 *  licensed under the terms outlined in the file COPYING at the root
 *  of the linux kernel sources.
 *
 * The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which
 * trigger an interrupt when one half of the programmed transfer size
 * has been xmitted.
 *
 * FIXME: little-endian only for now
 */

#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <asm/dmabrg.h>


/* registers and bits */

#define BRGATXSAR	0x00

#define BRGARXDAR	0x04

#define BRGATXTCR	0x08

#define BRGARXTCR	0x0C

#define BRGACR		0x10

#define BRGATXTCNT	0x14

#define BRGARXTCNT	0x18


#define ACR_RAR		(1 << 18)

#define ACR_RDS		(1 << 17)

#define ACR_RDE		(1 << 16)

#define ACR_TAR		(1 << 2)

#define ACR_TDS		(1 << 1)

#define ACR_TDE		(1 << 0)

/* receiver/transmitter data alignment */

#define ACR_RAM_NONE	(0 << 24)

#define ACR_RAM_4BYTE	(1 << 24)

#define ACR_RAM_2WORD	(2 << 24)

#define ACR_TAM_NONE	(0 << 8)

#define ACR_TAM_4BYTE	(1 << 8)

#define ACR_TAM_2WORD	(2 << 8)



struct camelot_pcm {
	
unsigned long mmio;  /* DMABRG audio channel control reg MMIO */
	
unsigned int txid;    /* ID of first DMABRG IRQ for this unit */

	
struct snd_pcm_substream *tx_ss;
	
unsigned long tx_period_size;
	
unsigned int  tx_period;

	
struct snd_pcm_substream *rx_ss;
	
unsigned long rx_period_size;
	
unsigned int  rx_period;

} 
cam_pcm_data[2] = {
	{
		.mmio	=	0xFE3C0040,
		.txid	=	DMABRGIRQ_A0TXF,
        },
	{
		.mmio	=	0xFE3C0060,
		.txid	=	DMABRGIRQ_A1TXF,
        },
};


#define BRGREG(x)	(*(unsigned long *)(cam->mmio + (x)))

/*
 * set a minimum of 16kb per period, to avoid interrupt-"storm" and
 * resulting skipping. In general, the bigger the minimum size, the
 * better for overall system performance. (The SH7760 is a puny CPU
 * with a slow SDRAM interface and poor internal bus bandwidth,
 * *especially* when the LCDC is active).  The minimum for the DMAC
 * is 8 bytes; 16kbytes are enough to get skip-free playback of a
 * 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain
 * reasonable responsiveness in MPlayer.
 */

#define DMABRG_PERIOD_MIN		16 * 1024

#define DMABRG_PERIOD_MAX		0x03fffffc

#define DMABRG_PREALLOC_BUFFER		32 * 1024

#define DMABRG_PREALLOC_BUFFER_MAX	32 * 1024


static struct snd_pcm_hardware camelot_pcm_hardware = {
	.info = (SNDRV_PCM_INFO_MMAP |
		SNDRV_PCM_INFO_INTERLEAVED |
		SNDRV_PCM_INFO_BLOCK_TRANSFER |
		SNDRV_PCM_INFO_MMAP_VALID |
		SNDRV_PCM_INFO_BATCH),
	.buffer_bytes_max =	DMABRG_PERIOD_MAX,
	.period_bytes_min =	DMABRG_PERIOD_MIN,
	.period_bytes_max =	DMABRG_PERIOD_MAX / 2,
	.periods_min =		2,
	.periods_max =		2,
	.fifo_size =		128,
};


static void camelot_txdma(void *data) { struct camelot_pcm *cam = data; cam->tx_period ^= 1; snd_pcm_period_elapsed(cam->tx_ss); }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss30100.00%1100.00%
Total30100.00%1100.00%


static void camelot_rxdma(void *data) { struct camelot_pcm *cam = data; cam->rx_period ^= 1; snd_pcm_period_elapsed(cam->rx_ss); }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss30100.00%1100.00%
Total30100.00%1100.00%


static int camelot_pcm_open(struct snd_pcm_substream *substream) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; int ret, dmairq; snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware); /* DMABRG buffer half/full events */ dmairq = (recv) ? cam->txid + 2 : cam->txid; if (recv) { cam->rx_ss = substream; ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam); if (unlikely(ret)) { pr_debug("audio unit %d irqs already taken!\n", rtd->cpu_dai->id); return -EBUSY; } (void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam); } else { cam->tx_ss = substream; ret = dmabrg_request_irq(dmairq, camelot_txdma, cam); if (unlikely(ret)) { pr_debug("audio unit %d irqs already taken!\n", rtd->cpu_dai->id); return -EBUSY; } (void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam); } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss200100.00%1100.00%
Total200100.00%1100.00%


static int camelot_pcm_close(struct snd_pcm_substream *substream) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; int dmairq; dmairq = (recv) ? cam->txid + 2 : cam->txid; if (recv) cam->rx_ss = NULL; else cam->tx_ss = NULL; dmabrg_free_irq(dmairq + 1); dmabrg_free_irq(dmairq); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss99100.00%1100.00%
Total99100.00%1100.00%


static int camelot_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *hw_params) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; int ret; ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params)); if (ret < 0) return ret; if (recv) { cam->rx_period_size = params_period_bytes(hw_params); cam->rx_period = 0; } else { cam->tx_period_size = params_period_bytes(hw_params); cam->tx_period = 0; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss119100.00%1100.00%
Total119100.00%1100.00%


static int camelot_hw_free(struct snd_pcm_substream *substream) { return snd_pcm_lib_free_pages(substream); }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss17100.00%1100.00%
Total17100.00%1100.00%


static int camelot_prepare(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct snd_soc_pcm_runtime *rtd = substream->private_data; struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; pr_debug("PCM data: addr 0x%08ulx len %d\n", (u32)runtime->dma_addr, runtime->dma_bytes); if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area; BRGREG(BRGATXTCR) = runtime->dma_bytes; } else { BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area; BRGREG(BRGARXTCR) = runtime->dma_bytes; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss120100.00%1100.00%
Total120100.00%1100.00%


static inline void dmabrg_play_dma_start(struct camelot_pcm *cam) { unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); /* start DMABRG engine: XFER start, auto-addr-reload */ BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss42100.00%1100.00%
Total42100.00%1100.00%


static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam) { unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); /* forcibly terminate data transmission */ BRGREG(BRGACR) = acr | ACR_TDS; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss38100.00%1100.00%
Total38100.00%1100.00%


static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam) { unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); /* start DMABRG engine: recv start, auto-reload */ BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss42100.00%1100.00%
Total42100.00%1100.00%


static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam) { unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); /* forcibly terminate data receiver */ BRGREG(BRGACR) = acr | ACR_RDS; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss38100.00%1100.00%
Total38100.00%1100.00%


static int camelot_trigger(struct snd_pcm_substream *substream, int cmd) { struct snd_soc_pcm_runtime *rtd = substream->private_data; struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; switch (cmd) { case SNDRV_PCM_TRIGGER_START: if (recv) dmabrg_rec_dma_start(cam); else dmabrg_play_dma_start(cam); break; case SNDRV_PCM_TRIGGER_STOP: if (recv) dmabrg_rec_dma_stop(cam); else dmabrg_play_dma_stop(cam); break; default: return -EINVAL; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss103100.00%1100.00%
Total103100.00%1100.00%


static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; struct snd_soc_pcm_runtime *rtd = substream->private_data; struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; unsigned long pos; /* cannot use the DMABRG pointer register: under load, by the * time ALSA comes around to read the register, it is already * far ahead (or worse, already done with the fragment) of the * position at the time the IRQ was triggered, which results in * fast-playback sound in my test application (ScummVM) */ if (recv) pos = cam->rx_period ? cam->rx_period_size : 0; else pos = cam->tx_period ? cam->tx_period_size : 0; return bytes_to_frames(runtime, pos); }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss99100.00%1100.00%
Total99100.00%1100.00%

static struct snd_pcm_ops camelot_pcm_ops = { .open = camelot_pcm_open, .close = camelot_pcm_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = camelot_hw_params, .hw_free = camelot_hw_free, .prepare = camelot_prepare, .trigger = camelot_trigger, .pointer = camelot_pos, };
static int camelot_pcm_new(struct snd_soc_pcm_runtime *rtd) { struct snd_pcm *pcm = rtd->pcm; /* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel * in MMAP mode (i.e. aplay -M) */ snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS, snd_dma_continuous_data(GFP_KERNEL), DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss3177.50%150.00%
liam girdwoodliam girdwood922.50%150.00%
Total40100.00%2100.00%

static struct snd_soc_platform_driver sh7760_soc_platform = { .ops = &camelot_pcm_ops, .pcm_new = camelot_pcm_new, };
static int sh7760_soc_platform_probe(struct platform_device *pdev) { return devm_snd_soc_register_platform(&pdev->dev, &sh7760_soc_platform); }

Contributors

PersonTokensPropCommitsCommitProp
liam girdwoodliam girdwood1982.61%133.33%
manuel laussmanuel lauss313.04%133.33%
axel linaxel lin14.35%133.33%
Total23100.00%3100.00%

static struct platform_driver sh7760_pcm_driver = { .driver = { .name = "sh7760-pcm-audio", }, .probe = sh7760_soc_platform_probe, }; module_platform_driver(sh7760_pcm_driver); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver"); MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");

Overall Contributors

PersonTokensPropCommitsCommitProp
manuel laussmanuel lauss134195.44%111.11%
liam girdwoodliam girdwood523.70%222.22%
mark brownmark brown30.21%111.11%
tejun heotejun heo30.21%111.11%
lars-peter clausenlars-peter clausen20.14%111.11%
takashi iwaitakashi iwai20.14%111.11%
axel linaxel lin20.14%222.22%
Total1405100.00%9100.00%
Directory: sound/soc/sh
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}