June 2012 - Alsa-devel - mailman.alsa-project.org

Re: [alsa-devel] [PATCH 3/3] ASoC: follow the updated samsung DMA common operations
by Kukjin Kim 19 Jun '12

19 Jun '12

Boojin Kim wrote: > > Mark Brown wrote > > > This patch uses config() function to configure DMA transmit options. > > > > Acked-by: Mark Brown <broonie(a)opensource.wolfsonmicro.com> > > Thanks for your ack and let me pick this up in Samsung tree. Best regards, Kgene. -- Kukjin Kim <kgene.kim(a)samsung.com>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. > > It'd be good if we could get all the older Samsung platforms moved over > to dmaengine... > Thanks for your ack :) > And, Our engineer's preparing to move the older Samsung dma driver into > dmaengine.

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Re: [alsa-devel] [PATCH 1/3] ARM: SAMSUNG: Add config() function in DMA common operations
by Kukjin Kim 19 Jun '12

19 Jun '12

Boojin Kim wrote: > > This patch adds config() that configures DMA transmit option. > This function was originally included in request(). > But, Some DMA client driver requires to change the configuration after > request(). > So, This patch picks up it from request(). > > Signed-off-by: Boojin Kim <boojin.kim(a)samsung.com> > --- > arch/arm/plat-samsung/dma-ops.c | 77 ++++++++++++++----------- > arch/arm/plat-samsung/include/plat/dma-ops.h | 20 ++++--- > arch/arm/plat-samsung/s3c-dma-ops.c | 39 +++++++------ > 3 files changed, 77 insertions(+), 59 deletions(-) > > diff --git a/arch/arm/plat-samsung/dma-ops.c b/arch/arm/plat-samsung/dma- > ops.c > index eb9f4f5..51d8590 100644 > --- a/arch/arm/plat-samsung/dma-ops.c > +++ b/arch/arm/plat-samsung/dma-ops.c > @@ -19,72 +19,80 @@ > #include <mach/dma.h> > > static unsigned samsung_dmadev_request(enum dma_ch dma_ch, > - struct samsung_dma_info *info) > + struct samsung_dma_req *param) > { > - struct dma_chan *chan; > dma_cap_mask_t mask; > - struct dma_slave_config slave_config; > void *filter_param; > > dma_cap_zero(mask); > - dma_cap_set(info->cap, mask); > + dma_cap_set(param->cap, mask); > > /* > * If a dma channel property of a device node from device tree is > * specified, use that as the fliter parameter. > */ > - filter_param = (dma_ch == DMACH_DT_PROP) ? (void *)info- > >dt_dmach_prop : > - (void *)dma_ch; > - chan = dma_request_channel(mask, pl330_filter, filter_param); > + filter_param = (dma_ch == DMACH_DT_PROP) ? > + (void *)param->dt_dmach_prop : (void *)dma_ch; > + return (unsigned)dma_request_channel(mask, pl330_filter, > filter_param); > +} > > - if (info->direction == DMA_DEV_TO_MEM) { > +static int samsung_dmadev_release(unsigned ch, > + struct s3c2410_dma_client *client) > +{ > + dma_release_channel((struct dma_chan *)ch); > + > + return 0; > +} > + > +static int samsung_dmadev_config(unsigned ch, > + struct samsung_dma_config *param) > +{ > + struct dma_chan *chan = (struct dma_chan *)ch; > + struct dma_slave_config slave_config; > + > + if (param->direction == DMA_DEV_TO_MEM) { > memset(&slave_config, 0, sizeof(struct dma_slave_config)); > - slave_config.direction = info->direction; > - slave_config.src_addr = info->fifo; > - slave_config.src_addr_width = info->width; > + slave_config.direction = param->direction; > + slave_config.src_addr = param->fifo; > + slave_config.src_addr_width = param->width; > slave_config.src_maxburst = 1; > dmaengine_slave_config(chan, &slave_config); > - } else if (info->direction == DMA_MEM_TO_DEV) { > + } else if (param->direction == DMA_MEM_TO_DEV) { > memset(&slave_config, 0, sizeof(struct dma_slave_config)); > - slave_config.direction = info->direction; > - slave_config.dst_addr = info->fifo; > - slave_config.dst_addr_width = info->width; > + slave_config.direction = param->direction; > + slave_config.dst_addr = param->fifo; > + slave_config.dst_addr_width = param->width; > slave_config.dst_maxburst = 1; > dmaengine_slave_config(chan, &slave_config); > + } else { > + printk(KERN_WARNING "unsupported direction\n"); > + return -EINVAL; > } > > - return (unsigned)chan; > -} > - > -static int samsung_dmadev_release(unsigned ch, > - struct s3c2410_dma_client *client) > -{ > - dma_release_channel((struct dma_chan *)ch); > - > return 0; > } > > static int samsung_dmadev_prepare(unsigned ch, > - struct samsung_dma_prep_info *info) > + struct samsung_dma_prep *param) > { > struct scatterlist sg; > struct dma_chan *chan = (struct dma_chan *)ch; > struct dma_async_tx_descriptor *desc; > > - switch (info->cap) { > + switch (param->cap) { > case DMA_SLAVE: > sg_init_table(&sg, 1); > - sg_dma_len(&sg) = info->len; > - sg_set_page(&sg, pfn_to_page(PFN_DOWN(info->buf)), > - info->len, offset_in_page(info->buf)); > - sg_dma_address(&sg) = info->buf; > + sg_dma_len(&sg) = param->len; > + sg_set_page(&sg, pfn_to_page(PFN_DOWN(param->buf)), > + param->len, offset_in_page(param->buf)); > + sg_dma_address(&sg) = param->buf; > > desc = dmaengine_prep_slave_sg(chan, > - &sg, 1, info->direction, DMA_PREP_INTERRUPT); > + &sg, 1, param->direction, DMA_PREP_INTERRUPT); > break; > case DMA_CYCLIC: > - desc = dmaengine_prep_dma_cyclic(chan, > - info->buf, info->len, info->period, info->direction); > + desc = dmaengine_prep_dma_cyclic(chan, param->buf, > + param->len, param->period, param->direction); > break; > default: > dev_err(&chan->dev->device, "unsupported format\n"); > @@ -96,8 +104,8 @@ static int samsung_dmadev_prepare(unsigned ch, > return -EFAULT; > } > > - desc->callback = info->fp; > - desc->callback_param = info->fp_param; > + desc->callback = param->fp; > + desc->callback_param = param->fp_param; > > dmaengine_submit((struct dma_async_tx_descriptor *)desc); > > @@ -119,6 +127,7 @@ static inline int samsung_dmadev_flush(unsigned ch) > static struct samsung_dma_ops dmadev_ops = { > .request = samsung_dmadev_request, > .release = samsung_dmadev_release, > + .config = samsung_dmadev_config, > .prepare = samsung_dmadev_prepare, > .trigger = samsung_dmadev_trigger, > .started = NULL, > diff --git a/arch/arm/plat-samsung/include/plat/dma-ops.h b/arch/arm/plat- > samsung/include/plat/dma-ops.h > index 71a6827..f5144cd 100644 > --- a/arch/arm/plat-samsung/include/plat/dma-ops.h > +++ b/arch/arm/plat-samsung/include/plat/dma-ops.h > @@ -16,7 +16,13 @@ > #include <linux/dmaengine.h> > #include <mach/dma.h> > > -struct samsung_dma_prep_info { > +struct samsung_dma_req { > + enum dma_transaction_type cap; > + struct property *dt_dmach_prop; > + struct s3c2410_dma_client *client; > +}; > + > +struct samsung_dma_prep { > enum dma_transaction_type cap; > enum dma_transfer_direction direction; > dma_addr_t buf; > @@ -26,19 +32,17 @@ struct samsung_dma_prep_info { > void *fp_param; > }; > > -struct samsung_dma_info { > - enum dma_transaction_type cap; > +struct samsung_dma_config { > enum dma_transfer_direction direction; > enum dma_slave_buswidth width; > dma_addr_t fifo; > - struct s3c2410_dma_client *client; > - struct property *dt_dmach_prop; > }; > > struct samsung_dma_ops { > - unsigned (*request)(enum dma_ch ch, struct samsung_dma_info *info); > - int (*release)(unsigned ch, struct s3c2410_dma_client *client); > - int (*prepare)(unsigned ch, struct samsung_dma_prep_info *info); > + unsigned (*request)(enum dma_ch ch, struct samsung_dma_req *param); > + int (*release)(unsigned ch, void *param); > + int (*config)(unsigned ch, struct samsung_dma_config *param); > + int (*prepare)(unsigned ch, struct samsung_dma_prep *param); > int (*trigger)(unsigned ch); > int (*started)(unsigned ch); > int (*flush)(unsigned ch); > diff --git a/arch/arm/plat-samsung/s3c-dma-ops.c b/arch/arm/plat- > samsung/s3c-dma-ops.c > index 7814949..f99448c 100644 > --- a/arch/arm/plat-samsung/s3c-dma-ops.c > +++ b/arch/arm/plat-samsung/s3c-dma-ops.c > @@ -36,30 +36,26 @@ static void s3c_dma_cb(struct s3c2410_dma_chan > *channel, void *param, > } > > static unsigned s3c_dma_request(enum dma_ch dma_ch, > - struct samsung_dma_info *info) > + struct samsung_dma_req *param) > { > struct cb_data *data; > > - if (s3c2410_dma_request(dma_ch, info->client, NULL) < 0) { > - s3c2410_dma_free(dma_ch, info->client); > + if (s3c2410_dma_request(dma_ch, param->client, NULL) < 0) { > + s3c2410_dma_free(dma_ch, param->client); > return 0; > } > > + if (param->cap == DMA_CYCLIC) > + s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR); > + > data = kzalloc(sizeof(struct cb_data), GFP_KERNEL); > data->ch = dma_ch; > list_add_tail(&data->node, &dma_list); > > - s3c2410_dma_devconfig(dma_ch, info->direction, info->fifo); > - > - if (info->cap == DMA_CYCLIC) > - s3c2410_dma_setflags(dma_ch, S3C2410_DMAF_CIRCULAR); > - > - s3c2410_dma_config(dma_ch, info->width); > - > return (unsigned)dma_ch; > } > > -static int s3c_dma_release(unsigned ch, struct s3c2410_dma_client *client) > +static int s3c_dma_release(unsigned ch, void *param) > { > struct cb_data *data; > > @@ -68,16 +64,24 @@ static int s3c_dma_release(unsigned ch, struct > s3c2410_dma_client *client) > break; > list_del(&data->node); > > - s3c2410_dma_free(ch, client); > + s3c2410_dma_free(ch, param); > kfree(data); > > return 0; > } > > -static int s3c_dma_prepare(unsigned ch, struct samsung_dma_prep_info > *info) > +static int s3c_dma_config(unsigned ch, struct samsung_dma_config *param) > +{ > + s3c2410_dma_devconfig(ch, param->direction, param->fifo); > + s3c2410_dma_config(ch, param->width); > + > + return 0; > +} > + > +static int s3c_dma_prepare(unsigned ch, struct samsung_dma_prep *param) > { > struct cb_data *data; > - int len = (info->cap == DMA_CYCLIC) ? info->period : info->len; > + int len = (param->cap == DMA_CYCLIC) ? param->period : param->len; > > list_for_each_entry(data, &dma_list, node) > if (data->ch == ch) > @@ -85,11 +89,11 @@ static int s3c_dma_prepare(unsigned ch, struct > samsung_dma_prep_info *info) > > if (!data->fp) { > s3c2410_dma_set_buffdone_fn(ch, s3c_dma_cb); > - data->fp = info->fp; > - data->fp_param = info->fp_param; > + data->fp = param->fp; > + data->fp_param = param->fp_param; > } > > - s3c2410_dma_enqueue(ch, (void *)data, info->buf, len); > + s3c2410_dma_enqueue(ch, (void *)data, param->buf, len); > > return 0; > } > @@ -117,6 +121,7 @@ static inline int s3c_dma_stop(unsigned ch) > static struct samsung_dma_ops s3c_dma_ops = { > .request = s3c_dma_request, > .release = s3c_dma_release, > + .config = s3c_dma_config, > .prepare = s3c_dma_prepare, > .trigger = s3c_dma_trigger, > .started = s3c_dma_started, > -- > 1.7.1 Looks good to me but need to ack on spi patch in this series. I think, this series should be picked up together. Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim(a)samsung.com>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd.

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Re: [alsa-devel] [PATCH 2/3] spi: Add the use of DMA config operation
by Kukjin Kim 19 Jun '12

19 Jun '12

Boojin Kim wrote: > > Config operation is separated from request operation in DMA common > operation. > Because spi driver can change the DMA config for every transfer. > So this patch is using the separated DMA config operation. > > Signed-off-by: Boojin Kim <boojin.kim(a)samsung.com> > Signed-off-by: Kyoungil Kim <ki0351.kim(a)samsung.com> > --- > drivers/spi/spi-s3c64xx.c | 33 +++++++++++++++++++-------------- > 1 files changed, 19 insertions(+), 14 deletions(-) > > diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c > index 15f864d..f4e2341 100644 > --- a/drivers/spi/spi-s3c64xx.c > +++ b/drivers/spi/spi-s3c64xx.c > @@ -262,14 +262,24 @@ static void prepare_dma(struct s3c64xx_spi_dma_data > *dma, > unsigned len, dma_addr_t buf) > { > struct s3c64xx_spi_driver_data *sdd; > - struct samsung_dma_prep_info info; > + struct samsung_dma_prep info; > + struct samsung_dma_config config; > > - if (dma->direction == DMA_DEV_TO_MEM) > + if (dma->direction == DMA_DEV_TO_MEM) { > sdd = container_of((void *)dma, > struct s3c64xx_spi_driver_data, rx_dma); > - else > + config.direction = sdd->rx_dma.direction; > + config.fifo = sdd->sfr_start + S3C64XX_SPI_RX_DATA; > + config.width = sdd->cur_bpw / 8; > + sdd->ops->config(sdd->rx_dma.ch, &config); > + } else { > sdd = container_of((void *)dma, > struct s3c64xx_spi_driver_data, tx_dma); > + config.direction = sdd->tx_dma.direction; > + config.fifo = sdd->sfr_start + S3C64XX_SPI_TX_DATA; > + config.width = sdd->cur_bpw / 8; > + sdd->ops->config(sdd->tx_dma.ch, &config); > + } > > info.cap = DMA_SLAVE; > info.len = len; > @@ -284,20 +294,15 @@ static void prepare_dma(struct s3c64xx_spi_dma_data > *dma, > > static int acquire_dma(struct s3c64xx_spi_driver_data *sdd) > { > - struct samsung_dma_info info; > + struct samsung_dma_req req; > > sdd->ops = samsung_dma_get_ops(); > > - info.cap = DMA_SLAVE; > - info.client = &s3c64xx_spi_dma_client; > - info.width = sdd->cur_bpw / 8; > - > - info.direction = sdd->rx_dma.direction; > - info.fifo = sdd->sfr_start + S3C64XX_SPI_RX_DATA; > - sdd->rx_dma.ch = sdd->ops->request(sdd->rx_dma.dmach, &info); > - info.direction = sdd->tx_dma.direction; > - info.fifo = sdd->sfr_start + S3C64XX_SPI_TX_DATA; > - sdd->tx_dma.ch = sdd->ops->request(sdd->tx_dma.dmach, &info); > + req.cap = DMA_SLAVE; > + req.client = &s3c64xx_spi_dma_client; > + > + sdd->rx_dma.ch = sdd->ops->request(sdd->rx_dma.dmach, &req); > + sdd->tx_dma.ch = sdd->ops->request(sdd->tx_dma.dmach, &req); > > return 1; > } > -- > 1.7.1 Hi Grant, I think, this is needed to support Samsung SPI with DMA and this has dependency with other patches in this series. If you're ok on this, please reply with your ack :) so that I can take this series together. Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim(a)samsung.com>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd.

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[alsa-devel] [PATCH] ALSA-LIB - remove Logitech Web Camera from blacklist
by Raymond Yau 19 Jun '12

19 Jun '12

- the commit which add Logitech Web Camera to the blacklist is redundant since Web Camera does not has any playback device and Pulseaudio does not support digital capture

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Re: [alsa-devel] [PATCH 2/2] sound: tegra_alc5632: Adjust to of_get_named_gpio() change
by Leon Romanovsky 19 Jun '12

19 Jun '12

On Mon, Jun 18, 2012 at 8:28 PM, Alexandre Pereira da Silva <aletes.xgr(a)gmail.com> wrote: > On Mon, Jun 18, 2012 at 1:42 PM, Roland Stigge <stigge(a)antcom.de> wrote: >> of_get_named_gpio() was changed to return -EPROBE_DEFER in case of >> gpios not probed yet. This patch adjusts tegra_alc5632 to this. >> >> Signed-off-by: Roland Stigge <stigge(a)antcom.de> > Acked-by: Alexandre Pereira da Silva <aletes.xgr(a)gmail.com> Hi Alexandre, Sorry to be rude, but can you explain me why did you "Acked-by" on this patch ? I don't see your name in git log for tegra_alc5632.c file: http://git.kernel.org/?p=linux/kernel/git/broonie/sound.git;a=history;f=sou… Thanks. -- Leon Romanovsky | Independent Linux Consultant www.leon.nu | leon(a)leon.nu

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Re: [alsa-devel] [PATCH] sound/gpio: of_get_named_gpio() return -EPROBE_DEFER if GPIO deferred
by Stephen Warren 18 Jun '12

18 Jun '12

On 06/18/2012 11:22 AM, Roland Stigge wrote: > of_get_named_gpio_flags() and of_get_named_gpio() return -EPROBE_DEFER if the > respective GPIO is not (yet) available. This is useful if driver's probe() > functions try to get a GPIO whose controller isn't probed yet. Thus, the driver > can be probed again later on. > > The function still returns -EINVAL on other errors (parse error or node doesn't > exist). This way, the case of an optional/intentionally missing GPIO is handled > appropriately. > > For this change, two sound drivers (tegra_{alc5632,wm8903}) need to be > adjusted. Acked-by: Stephen Warren <swarren(a)wwwdotorg.org> (That applies to the two separate sound patches too, if needed!)

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Re: [alsa-devel] [PATCH 1/2] sound: tegra_wm8903: Adjust to of_get_named_gpio() change
by Mark Brown 18 Jun '12

18 Jun '12

On Mon, Jun 18, 2012 at 07:00:14PM +0200, Roland Stigge wrote: > Basically, yes. But this would mean that doing via gpio, we would need > to pull other stuff from the sound tree over to gpio to build upon > because "my" tegra_* sound patches won't apply to the gpio branch currently. Oh, yes. Stephen's gone and reorganised all that code which means it's not a trivial merge. Ho hum. I'm happy to apply them if folks are comfortable with it, I guess ideally I'd be able to pull a branch with the gpio changes in and then apply on top of that.

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Re: [alsa-devel] [PATCH 1/2] sound: tegra_wm8903: Adjust to of_get_named_gpio() change
by Mark Brown 18 Jun '12

18 Jun '12

On Mon, Jun 18, 2012 at 06:42:21PM +0200, Roland Stigge wrote: > of_get_named_gpio() was changed to return -EPROBE_DEFER in case of > gpios not probed yet. This patch adjusts tegra_wm8903 to this. So, I saw from the other thread that this didn't actually happen yet - I guess the best thing is to merge this along with the changes for introducing -EPROBE_DEFER. Acked-by: Mark Brown <broonie(a)opensource.wolfsonmicro.com>

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[alsa-devel] How to redefine "default" to be equivalent to "sysdefault"?
by Tanu Kaskinen 18 Jun '12

18 Jun '12

Hi, I have a file with the following contents: # This file an alsa configuration file, used by pasuspender to make the # "default" Alsa device work while PulseAudio is in suspended state. # Include the system configuration first. Is there any easier way to do this? # 14 lines for including one file is a bit much... @hooks [ { func load files [ { @func concat strings [ { @func datadir } "/alsa.conf" ] } ] } ] # Redefine "default" to be the same as "sysdefault". On most systems # "sysdefault" is configured to use dmix. pcm.!default sysdefault That doesn't do what I want it to do. When I run ALSA_CONFIG_PATH=/path/to/file.conf aplay -Ddefault ~/test.wav aplay still uses pulseaudio. Using "-Dsysdefault" instead of "-Ddefault" doesn't use pulseaudio, so "sysdefault" does what it's supposed to do. The problem is then: why doesn't "default" behave the same way as "sysdefault"? What error did I make? Below is "aplay -L" output with and without setting the environment variable. When the environment variable is set, "default" is listed twice, and "null" and "pulse" are included in the list while they are not included in the list when running aplay without the environment variable. What causes those differences? > ALSA_CONFIG_PATH=/path/to/file.conf aplay -L default Playback/recording through the PulseAudio sound server null Discard all samples (playback) or generate zero samples (capture) pulse Playback/recording through the PulseAudio sound server default Playback/recording through the PulseAudio sound server sysdefault:CARD=Intel HDA Intel, AD198x Analog Default Audio Device front:CARD=Intel,DEV=0 HDA Intel, AD198x Analog Front speakers surround40:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 4.0 Surround output to Front and Rear speakers surround41:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=Intel,DEV=0 HDA Intel, AD198x Digital IEC958 (S/PDIF) Digital Audio Output > aplay -L default Playback/recording through the PulseAudio sound server sysdefault:CARD=Intel HDA Intel, AD198x Analog Default Audio Device front:CARD=Intel,DEV=0 HDA Intel, AD198x Analog Front speakers surround40:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 4.0 Surround output to Front and Rear speakers surround41:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=Intel,DEV=0 HDA Intel, AD198x Analog 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=Intel,DEV=0 HDA Intel, AD198x Digital IEC958 (S/PDIF) Digital Audio Output -- Tanu

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[alsa-devel] [PATCH] ALSA: Add snd_pcm_rate_bit_to_rate()
by Dimitris Papastamos 18 Jun '12

18 Jun '12

This is essentially the reverse of snd_pcm_rate_to_rate_bit(). This is generally useful as the Compress API uses the rate bit directly and it helps to be able to map back to the actual sample rate. Signed-off-by: Dimitris Papastamos <dp(a)opensource.wolfsonmicro.com> --- include/sound/pcm.h | 1 + sound/core/pcm_misc.c | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 1d58d79..18ad1f1 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -892,6 +892,7 @@ extern const struct snd_pcm_hw_constraint_list snd_pcm_known_rates; int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime); unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate); +unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit); static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substream, struct snd_dma_buffer *bufp) diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c index 9c9eff9..d4fc1bf 100644 --- a/sound/core/pcm_misc.c +++ b/sound/core/pcm_misc.c @@ -488,3 +488,21 @@ unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate) return SNDRV_PCM_RATE_KNOT; } EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit); + +/** + * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate + * @rate_bit: the rate bit to convert + * + * Returns the sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag + * or 0 for an unknown rate bit + */ +unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit) +{ + unsigned int i; + + for (i = 0; i < snd_pcm_known_rates.count; i++) + if ((1u << i) == rate_bit) + return snd_pcm_known_rates.list[i]; + return 0; +} +EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate); -- 1.7.10.4

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