From 447d7c329145989e96cd0a89970a6e009407bad9 Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Sat, 4 Jun 2016 20:47:19 -0300 Subject: [PATCH] [media] tw686x: audio: Allow to configure the period size Currently, the driver has a fixed period size of 4096 bytes (2048 frames). Since this hardware can configure the audio capture size, this commit allows a period size range of [512-4096]. This is very useful to reduce the audio latency. Signed-off-by: Ezequiel Garcia Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/pci/tw686x/tw686x-audio.c | 48 ++++++++++++++++++--------------- drivers/media/pci/tw686x/tw686x-regs.h | 4 +++ drivers/media/pci/tw686x/tw686x.h | 5 ++-- 3 files changed, 34 insertions(+), 23 deletions(-) diff --git a/drivers/media/pci/tw686x/tw686x-audio.c b/drivers/media/pci/tw686x/tw686x-audio.c index a14d1b0..987a226 100644 --- a/drivers/media/pci/tw686x/tw686x-audio.c +++ b/drivers/media/pci/tw686x/tw686x-audio.c @@ -71,7 +71,7 @@ void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests, desc = &ac->dma_descs[pb]; if (desc->virt) { memcpy(done->virt, desc->virt, - desc->size); + dev->period_size); } else { u32 reg = pb ? ADMA_B_ADDR[ch] : ADMA_P_ADDR[ch]; reg_write(dev, reg, next->dma); @@ -93,10 +93,11 @@ static int tw686x_pcm_hw_free(struct snd_pcm_substream *ss) } /* - * The audio device rate is global and shared among all + * Audio parameters are global and shared among all * capture channels. The driver makes no effort to prevent - * rate modifications. User is free change the rate, but it - * means changing the rate for all capture sub-devices. + * any modifications. User is free change the audio rate, + * or period size, thus changing parameters for all capture + * sub-devices. */ static const struct snd_pcm_hardware tw686x_capture_hw = { .info = (SNDRV_PCM_INFO_MMAP | @@ -109,9 +110,9 @@ static const struct snd_pcm_hardware tw686x_capture_hw = { .rate_max = 48000, .channels_min = 1, .channels_max = 1, - .buffer_bytes_max = TW686X_AUDIO_PAGE_MAX * TW686X_AUDIO_PAGE_SZ, - .period_bytes_min = TW686X_AUDIO_PAGE_SZ, - .period_bytes_max = TW686X_AUDIO_PAGE_SZ, + .buffer_bytes_max = TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX, + .period_bytes_min = AUDIO_DMA_SIZE_MIN, + .period_bytes_max = AUDIO_DMA_SIZE_MAX, .periods_min = TW686X_AUDIO_PERIODS_MIN, .periods_max = TW686X_AUDIO_PERIODS_MAX, }; @@ -166,12 +167,21 @@ static int tw686x_pcm_prepare(struct snd_pcm_substream *ss) reg_write(dev, AUDIO_CONTROL2, reg); } - if (period_size != TW686X_AUDIO_PAGE_SZ || - rt->periods < TW686X_AUDIO_PERIODS_MIN || - rt->periods > TW686X_AUDIO_PERIODS_MAX) { - return -EINVAL; + if (dev->period_size != period_size) { + u32 reg; + + dev->period_size = period_size; + reg = reg_read(dev, AUDIO_CONTROL1); + reg &= ~(AUDIO_DMA_SIZE_MASK << AUDIO_DMA_SIZE_SHIFT); + reg |= period_size << AUDIO_DMA_SIZE_SHIFT; + + reg_write(dev, AUDIO_CONTROL1, reg); } + if (rt->periods < TW686X_AUDIO_PERIODS_MIN || + rt->periods > TW686X_AUDIO_PERIODS_MAX) + return -EINVAL; + spin_lock_irqsave(&ac->lock, flags); INIT_LIST_HEAD(&ac->buf_list); @@ -282,8 +292,8 @@ static int tw686x_snd_pcm_init(struct tw686x_dev *dev) return snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(dev->pci_dev), - TW686X_AUDIO_PAGE_MAX * TW686X_AUDIO_PAGE_SZ, - TW686X_AUDIO_PAGE_MAX * TW686X_AUDIO_PAGE_SZ); + TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX, + TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX); } static void tw686x_audio_dma_free(struct tw686x_dev *dev, @@ -318,7 +328,7 @@ static int tw686x_audio_dma_alloc(struct tw686x_dev *dev, u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch]; void *virt; - virt = pci_alloc_consistent(dev->pci_dev, TW686X_AUDIO_PAGE_SZ, + virt = pci_alloc_consistent(dev->pci_dev, AUDIO_DMA_SIZE_MAX, &ac->dma_descs[pb].phys); if (!virt) { dev_err(&dev->pci_dev->dev, @@ -327,7 +337,7 @@ static int tw686x_audio_dma_alloc(struct tw686x_dev *dev, return -ENOMEM; } ac->dma_descs[pb].virt = virt; - ac->dma_descs[pb].size = TW686X_AUDIO_PAGE_SZ; + ac->dma_descs[pb].size = AUDIO_DMA_SIZE_MAX; reg_write(dev, reg, ac->dma_descs[pb].phys); } return 0; @@ -358,12 +368,8 @@ int tw686x_audio_init(struct tw686x_dev *dev) struct snd_card *card; int err, ch; - /* - * AUDIO_CONTROL1 - * DMA byte length [31:19] = 4096 (i.e. ALSA period) - * External audio enable [0] = enabled - */ - reg_write(dev, AUDIO_CONTROL1, 0x80000001); + /* Enable external audio */ + reg_write(dev, AUDIO_CONTROL1, BIT(0)); err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1, diff --git a/drivers/media/pci/tw686x/tw686x-regs.h b/drivers/media/pci/tw686x/tw686x-regs.h index 37c39bc..15a9566 100644 --- a/drivers/media/pci/tw686x/tw686x-regs.h +++ b/drivers/media/pci/tw686x/tw686x-regs.h @@ -105,6 +105,10 @@ 0x2d0, 0x2d1, 0x2d2, 0x2d3 }) #define SYS_MODE_DMA_SHIFT 13 +#define AUDIO_DMA_SIZE_SHIFT 19 +#define AUDIO_DMA_SIZE_MIN SZ_512 +#define AUDIO_DMA_SIZE_MAX SZ_4K +#define AUDIO_DMA_SIZE_MASK (SZ_8K - 1) #define DMA_CMD_ENABLE BIT(31) #define INT_STATUS_DMA_TOUT BIT(17) diff --git a/drivers/media/pci/tw686x/tw686x.h b/drivers/media/pci/tw686x/tw686x.h index 25e3c84..4acb905 100644 --- a/drivers/media/pci/tw686x/tw686x.h +++ b/drivers/media/pci/tw686x/tw686x.h @@ -27,7 +27,6 @@ #define TYPE_SECOND_GEN 0x10 #define TW686X_DEF_PHASE_REF 0x1518 -#define TW686X_AUDIO_PAGE_SZ 4096 #define TW686X_AUDIO_PAGE_MAX 16 #define TW686X_AUDIO_PERIODS_MIN 2 #define TW686X_AUDIO_PERIODS_MAX TW686X_AUDIO_PAGE_MAX @@ -139,7 +138,9 @@ struct tw686x_dev { struct tw686x_video_channel *video_channels; struct tw686x_audio_channel *audio_channels; - int audio_rate; /* per-device value */ + /* Per-device audio parameters */ + int audio_rate; + int period_size; struct timer_list dma_delay_timer; u32 pending_dma_en; /* must be protected by lock */ -- 2.7.4