// SPDX-License-Identifier: GPL-2.0-only /* * SAA713x ALSA support for V4L */ #include "saa7134.h" #include "saa7134-reg.h" #include <linux/init.h> #include <linux/slab.h> #include <linux/time.h> #include <linux/wait.h> #include <linux/module.h> #include <sound/core.h> #include <sound/control.h> #include <sound/pcm.h> #include <sound/pcm_params.h> #include <sound/initval.h> #include <linux/interrupt.h> #include <linux/vmalloc.h> /* * Configuration macros */ /* defaults */ #define MIXER_ADDR_UNSELECTED … #define MIXER_ADDR_TVTUNER … #define MIXER_ADDR_LINE1 … #define MIXER_ADDR_LINE2 … #define MIXER_ADDR_LAST … static int index[SNDRV_CARDS] = …; /* Index 0-MAX */ static char *id[SNDRV_CARDS] = …; /* ID for this card */ static int enable[SNDRV_CARDS] = …; module_param_array(…); module_param_array(…); MODULE_PARM_DESC(…) …; MODULE_PARM_DESC(…) …; /* * Main chip structure */ snd_card_saa7134_t; /* * PCM structure */ snd_card_saa7134_pcm_t; static struct snd_card *snd_saa7134_cards[SNDRV_CARDS]; /* * saa7134 DMA audio stop * * Called when the capture device is released or the buffer overflows * * - Copied verbatim from saa7134-oss's dsp_dma_stop. * */ static void saa7134_dma_stop(struct saa7134_dev *dev) { … } /* * saa7134 DMA audio start * * Called when preparing the capture device for use * * - Copied verbatim from saa7134-oss's dsp_dma_start. * */ static void saa7134_dma_start(struct saa7134_dev *dev) { … } /* * saa7134 audio DMA IRQ handler * * Called whenever we get an SAA7134_IRQ_REPORT_DONE_RA3 interrupt * Handles shifting between the 2 buffers, manages the read counters, * and notifies ALSA when periods elapse * * - Mostly copied from saa7134-oss's saa7134_irq_oss_done. * */ static void saa7134_irq_alsa_done(struct saa7134_dev *dev, unsigned long status) { … } /* * IRQ request handler * * Runs along with saa7134's IRQ handler, discards anything that isn't * DMA sound * */ static irqreturn_t saa7134_alsa_irq(int irq, void *dev_id) { … } /* * ALSA capture trigger * * - One of the ALSA capture callbacks. * * Called whenever a capture is started or stopped. Must be defined, * but there's nothing we want to do here * */ static int snd_card_saa7134_capture_trigger(struct snd_pcm_substream * substream, int cmd) { … } static int saa7134_alsa_dma_init(struct saa7134_dev *dev, unsigned long nr_pages) { … } static int saa7134_alsa_dma_map(struct saa7134_dev *dev) { … } static int saa7134_alsa_dma_unmap(struct saa7134_dev *dev) { … } static int saa7134_alsa_dma_free(struct saa7134_dmasound *dma) { … } /* * DMA buffer initialization * * Uses V4L functions to initialize the DMA. Shouldn't be necessary in * ALSA, but I was unable to use ALSA's own DMA, and had to force the * usage of V4L's * * - Copied verbatim from saa7134-oss. * */ static int dsp_buffer_init(struct saa7134_dev *dev) { … } /* * DMA buffer release * * Called after closing the device, during snd_card_saa7134_capture_close * */ static int dsp_buffer_free(struct saa7134_dev *dev) { … } /* * Setting the capture source and updating the ALSA controls */ static int snd_saa7134_capsrc_set(struct snd_kcontrol *kcontrol, int left, int right, bool force_notify) { … } /* * ALSA PCM preparation * * - One of the ALSA capture callbacks. * * Called right after the capture device is opened, this function configures * the buffer using the previously defined functions, allocates the memory, * sets up the hardware registers, and then starts the DMA. When this function * returns, the audio should be flowing. * */ static int snd_card_saa7134_capture_prepare(struct snd_pcm_substream * substream) { … } /* * ALSA pointer fetching * * - One of the ALSA capture callbacks. * * Called whenever a period elapses, it must return the current hardware * position of the buffer. * Also resets the read counter used to prevent overruns * */ static snd_pcm_uframes_t snd_card_saa7134_capture_pointer(struct snd_pcm_substream * substream) { … } /* * ALSA hardware capabilities definition * * Report only 32kHz for ALSA: * * - SAA7133/35 uses DDEP (DemDec Easy Programming mode), which works in 32kHz * only * - SAA7134 for TV mode uses DemDec mode (32kHz) * - Radio works in 32kHz only * - When recording 48kHz from Line1/Line2, switching of capture source to TV * means * switching to 32kHz without any frequency translation */ static const struct snd_pcm_hardware snd_card_saa7134_capture = …; static void snd_card_saa7134_runtime_free(struct snd_pcm_runtime *runtime) { … } /* * ALSA hardware params * * - One of the ALSA capture callbacks. * * Called on initialization, right before the PCM preparation * */ static int snd_card_saa7134_hw_params(struct snd_pcm_substream * substream, struct snd_pcm_hw_params * hw_params) { … } /* * ALSA hardware release * * - One of the ALSA capture callbacks. * * Called after closing the device, but before snd_card_saa7134_capture_close * It stops the DMA audio and releases the buffers. * */ static int snd_card_saa7134_hw_free(struct snd_pcm_substream * substream) { … } /* * ALSA capture finish * * - One of the ALSA capture callbacks. * * Called after closing the device. * */ static int snd_card_saa7134_capture_close(struct snd_pcm_substream * substream) { … } /* * ALSA capture start * * - One of the ALSA capture callbacks. * * Called when opening the device. It creates and populates the PCM * structure * */ static int snd_card_saa7134_capture_open(struct snd_pcm_substream * substream) { … } /* * page callback (needed for mmap) */ static struct page *snd_card_saa7134_page(struct snd_pcm_substream *substream, unsigned long offset) { … } /* * ALSA capture callbacks definition */ static const struct snd_pcm_ops snd_card_saa7134_capture_ops = …; /* * ALSA PCM setup * * Called when initializing the board. Sets up the name and hooks up * the callbacks * */ static int snd_card_saa7134_pcm(snd_card_saa7134_t *saa7134, int device) { … } #define SAA713x_VOLUME(xname, xindex, addr) … static int snd_saa7134_volume_info(struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo) { … } static int snd_saa7134_volume_get(struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol) { … } static int snd_saa7134_volume_put(struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol) { … } #define SAA713x_CAPSRC(xname, xindex, addr) … static int snd_saa7134_capsrc_info(struct snd_kcontrol * kcontrol, struct snd_ctl_elem_info * uinfo) { … } static int snd_saa7134_capsrc_get(struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol) { … } static int snd_saa7134_capsrc_put(struct snd_kcontrol * kcontrol, struct snd_ctl_elem_value * ucontrol) { … } static struct snd_kcontrol_new snd_saa7134_volume_controls[] = …; static struct snd_kcontrol_new snd_saa7134_capture_controls[] = …; /* * ALSA mixer setup * * Called when initializing the board. Sets up the name and hooks up * the callbacks * */ static int snd_card_saa7134_new_mixer(snd_card_saa7134_t * chip) { … } static void snd_saa7134_free(struct snd_card * card) { … } /* * ALSA initialization * * Called by the init routine, once for each saa7134 device present, * it creates the basic structures and registers the ALSA devices * */ static int alsa_card_saa7134_create(struct saa7134_dev *dev, int devnum) { … } static int alsa_device_init(struct saa7134_dev *dev) { … } static int alsa_device_exit(struct saa7134_dev *dev) { … } /* * Module initializer * * Loops through present saa7134 cards, and assigns an ALSA device * to each one * */ static int saa7134_alsa_init(void) { … } /* * Module destructor */ static void saa7134_alsa_exit(void) { … } /* We initialize this late, to make sure the sound system is up and running */ late_initcall(saa7134_alsa_init); module_exit(saa7134_alsa_exit); MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …;
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