[alsa-devel] [PATCH 3/5] [RFC]intel_hdmi_audio: driver module - ALSA intereaction
Takashi Iwai
tiwai at suse.de
Wed Nov 24 10:16:09 CET 2010
At Mon, 22 Nov 2010 19:09:44 +0530,
ramesh.babu at intel.com wrote:
>
> From: Ramesh Babu K V <ramesh.babu at intel.com>
>
> This patch creates intel_mid_hdmi_audio.c file. It intereacts
> with ALSA framework to enable the audio playback through HDMI
> interface. This code uses standard ALSA APIs.
>
> Signed-off-by: Ramesh Babu K V <ramesh.babu at intel.com>
> Signed-off-by: Sailaja Bandarupalli <sailaja.bandarupalli at intel.com>
> ---
> .../drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c | 546 ++++++++++++++++++++
> 1 files changed, 546 insertions(+), 0 deletions(-)
> create mode 100644 sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c
>
> diff --git a/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c
> new file mode 100644
> index 0000000..3ef4d48
> --- /dev/null
> +++ b/sound/drivers/intel_mid_hdmi/intel_mid_hdmi_audio.c
> @@ -0,0 +1,546 @@
> +/*
> + * intel_mid_hdmi_audio.c - Intel HDMI audio driver for MID
> + *
> + * Copyright (C) 2010 Intel Corp
> + * Authors: Sailaja Bandarupalli <sailaja.bandarupalli at intel.com>
> + * Ramesh Babu K V <ramesh.babu at intel.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; version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, write to the Free Software Foundation, Inc.,
> + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
> + *
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + * ALSA driver for Intel MID HDMI audio controller
> + */
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <sound/pcm.h>
> +#include <sound/pcm_params.h>
> +#include <sound/initval.h>
> +#include <sound/control.h>
> +#include <sound/initval.h>
> +#include "intel_mid_hdmi_audio.h"
> +
> +MODULE_AUTHOR("Sailaja Bandarupalli <sailaja.bandarupalli at intel.com>");
> +MODULE_AUTHOR("Ramesh Babu K V <ramesh.babu at intel.com>");
> +MODULE_DESCRIPTION("Intel HDMI Audio driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_SUPPORTED_DEVICE("{Intel,Intel_HAD}");
> +
> +#define INFO_FRAME_WORD1 0x000a0184
> +#define FIFO_THRESHOLD 0xFE
> +#define BYTES_PER_WORD 0x4
> +#define CH_STATUS_MAP_32KHZ 0x3
> +#define CH_STATUS_MAP_44KHZ 0x0
> +#define CH_STATUS_MAP_48KHZ 0x2
> +#define MAX_SMPL_WIDTH_20 0x0
> +#define MAX_SMPL_WIDTH_24 0x1
> +#define SMPL_WIDTH_16BITS 0x1
> +#define SMPL_WIDTH_24BITS 0x5
> +#define CHANNEL_ALLOCATION 0x1F
> +#define SET_BYTE0 0x000000FF
> +#define VALID_DIP_WORDS 3
> +#define LAYOUT0 0
> +#define LAYOUT1 1
> +
> +/*standard module options for ALSA. This module supports only one card*/
> +int hdmi_card_index = SNDRV_DEFAULT_IDX1;
> +char *hdmi_card_id = SNDRV_DEFAULT_STR1;
> +
> +module_param(hdmi_card_index, int, 0444);
> +MODULE_PARM_DESC(hdmi_card_index,
> + "Index value for INTEL Intel HDMI Audio controller.");
> +module_param(hdmi_card_id, charp, 0444);
> +MODULE_PARM_DESC(hdmi_card_id,
> + "ID string for INTEL Intel HDMI Audio controller.");
Drivers should expose the standard module options "index" and "id"
like others. Also they should be static.
> +
> +/* hardware capability structure */
> +static const struct snd_pcm_hardware snd_intel_hadstream = {
> + .info = (SNDRV_PCM_INFO_INTERLEAVED |
> + SNDRV_PCM_INFO_DOUBLE |
> + SNDRV_PCM_INFO_PAUSE |
> + SNDRV_PCM_INFO_RESUME |
You have to implement corresponding stuff if you mark the driver as
RESUME-able.
> + SNDRV_PCM_INFO_MMAP|
> + SNDRV_PCM_INFO_MMAP_VALID |
> + SNDRV_PCM_INFO_BATCH |
> + SNDRV_PCM_INFO_SYNC_START),
Is sync stuff implemented?
> + .formats = (SNDRV_PCM_FMTBIT_S24 |
> + SNDRV_PCM_FMTBIT_U24),
> + .rates = SNDRV_PCM_RATE_32000 |
> + SNDRV_PCM_RATE_44100 |
> + SNDRV_PCM_RATE_48000 |
> + SNDRV_PCM_RATE_64000 |
> + SNDRV_PCM_RATE_88200 |
> + SNDRV_PCM_RATE_96000 |
> + SNDRV_PCM_RATE_176400 |
> + SNDRV_PCM_RATE_192000,
> + .rate_min = HAD_MIN_RATE,
> + .rate_max = HAD_MAX_RATE,
> + .channels_min = HAD_MIN_CHANNEL,
> + .channels_max = HAD_MAX_CHANNEL,
> + .buffer_bytes_max = HAD_MAX_PERIOD_BYTES,
> + .period_bytes_min = HAD_MIN_PERIOD_BYTES,
> + .period_bytes_max = HAD_MAX_BUFFER,
> + .periods_min = HAD_MIN_PERIODS,
> + .periods_max = HAD_MAX_PERIODS,
> + .fifo_size = HAD_FIFO_SIZE,
> +};
> +
> +struct snd_intelhad *intelhaddata;
> +
> +/**
> +* snd_intelhad_open - stream initializations are done here
> +* @substream:substream for which the stream function is called
> +*
> +* This function is called whenever a PCM stream is opened
> +*/
> +static int snd_intelhad_open(struct snd_pcm_substream *substream)
> +{
> + struct snd_intelhad *intelhaddata;
> + struct snd_pcm_runtime *runtime;
> + struct had_stream_pvt *stream;
> + int retval;
> +
> + BUG_ON(!substream);
These BUG_ON() are superfluous. Better to remove.
> + pr_debug("had: snd_intelhad_open called\n");
> +
> + intelhaddata = snd_pcm_substream_chip(substream);
So... you assign the global variable at this open callback?
Any race?
> + runtime = substream->runtime;
> + /* set the runtime hw parameter with local snd_pcm_hardware struct */
> + runtime->hw = snd_intel_hadstream;
> +
> + stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> + if (!stream)
> + return -ENOMEM;
> + stream->stream_status = STREAM_INIT;
> + runtime->private_data = stream;
> + intelhaddata->reg_ops->hdmi_audio_write_register(AUD_HDMI_STATUS, 0);
> + retval = snd_pcm_hw_constraint_integer(runtime,
> + SNDRV_PCM_HW_PARAM_PERIODS);
stream is leaked when the error returned here.
> + return retval;
> +}
> +
> +/**
> +* had_period_elapsed - updates the hardware pointer status
> +* @had_substream:substream for which the stream function is called
> +*
> +*/
> +static void had_period_elapsed(void *had_substream)
> +{
> + struct snd_pcm_substream *substream = had_substream;
> + struct had_stream_pvt *stream;
> +
> + pr_debug("had: calling period elapsed\n");
> + if (!substream || !substream->runtime)
> + return;
> + stream = substream->runtime->private_data;
> + if (!stream)
> + return;
> +
> + if (stream->stream_status != STREAM_RUNNING)
> + return;
> + snd_pcm_period_elapsed(substream);
> + return;
> +}
> +
> +/**
> +* snd_intelhad_init_stream - internal function to initialize stream info
> +* @substream:substream for which the stream function is called
> +*
> +*/
> +static int snd_intelhad_init_stream(struct snd_pcm_substream *substream)
> +{
> + struct snd_intelhad *intelhaddata = snd_pcm_substream_chip(substream);
> +
> + pr_debug("had: setting buffer ptr param\n");
> + intelhaddata->stream_info.period_elapsed = had_period_elapsed;
> + intelhaddata->stream_info.had_substream = substream;
> + intelhaddata->stream_info.buffer_ptr = 0;
> + intelhaddata->stream_info.buffer_rendered = 0;
> + intelhaddata->stream_info.sfreq = substream->runtime->rate;
> + return 0;
> +}
> +
> +/**
> + * snd_intelhad_close- to free parameteres when stream is stopped
> + *
> + * @substream: substream for which the function is called
> + *
> + * This function is called by ALSA framework when stream is stopped
> + */
> +static int snd_intelhad_close(struct snd_pcm_substream *substream)
> +{
> + struct snd_intelhad *intelhaddata;
> + struct had_stream_pvt *stream;
> + BUG_ON(!substream);
> +
> + stream = substream->runtime->private_data;
> +
> + pr_debug("had: snd_intelhad_close called\n");
> + intelhaddata = snd_pcm_substream_chip(substream);
> + if (intelhaddata->stream_info.str_id) {
> + intelhaddata->playback_cnt--;
> + intelhaddata->stream_info.str_id = 0;
> + }
> + intelhaddata->stream_info.buffer_rendered = 0;
> + intelhaddata->stream_info.buffer_ptr = 0;
> +
> + kfree(substream->runtime->private_data);
> + return 0;
> +}
> +
> +/**
> + * snd_intelhad_hw_params- to setup the hardware parameters
> + * like allocating the buffers
> + *
> + * @substream: substream for which the function is called
> + * @hw_params: hardware parameters
> + *
> + * This function is called by ALSA framework when hardware params are set
> + */
> +static int snd_intelhad_hw_params(struct snd_pcm_substream *substream,
> + struct snd_pcm_hw_params *hw_params)
> +{
> + int retval;
> + struct snd_pcm_runtime *runtime;
> +
> + BUG_ON(!substream);
> + BUG_ON(!hw_params);
> + pr_debug("had: snd_intelhad_hw_params called\n");
> +
> + runtime = substream->runtime;
> +
> + retval = snd_pcm_lib_malloc_pages(substream,
> + params_buffer_bytes(hw_params));
> + if (retval < 0)
> + return -ENOMEM;
> + pr_debug("had: allocated memory = %d\n",
> + params_buffer_bytes(hw_params));
> + memset(substream->runtime->dma_area, 0,
> + params_buffer_bytes(hw_params));
> +
> + pr_debug("had: snd_intelhad_hw_params exited\n");
> + return retval;
> +}
> +
> +/**
> + * snd_intelhad_hw_free- to release the resources allocated during
> + * hardware params setup
> + *
> + * @substream: substream for which the function is called
> + *
> + * This function is called by ALSA framework before close callback.
> + *
> + */
> +static int snd_intelhad_hw_free(struct snd_pcm_substream *substream)
> +{
> + BUG_ON(!substream);
> + pr_debug("had: snd_intelhad_hw_free called\n");
> + return snd_pcm_lib_free_pages(substream);
> +}
> +
> +/**
> +* snd_intelhad_pcm_trigger - stream activities are handled here
> +* @substream:substream for which the stream function is called
> +* @cmd:the stream commamd thats requested from upper layer
> +* This function is called whenever an a stream activity is invoked
> +*/
> +static int snd_intelhad_pcm_trigger(struct snd_pcm_substream *substream,
> + int cmd)
> +{
> + int i, caps, retval = 0;
> + u32 regval = 0;
> + struct snd_intelhad *intelhaddata;
> + struct had_stream_pvt *stream;
> + struct hdmi_audio_registers_ops *reg_ops;
> + struct hdmi_audio_query_set_ops *query_ops;
> +
> + BUG_ON(!substream);
> +
> + intelhaddata = snd_pcm_substream_chip(substream);
> + stream = substream->runtime->private_data;
> + reg_ops = intelhaddata->reg_ops;
> + query_ops = intelhaddata->query_ops;
> +
> + switch (cmd) {
> + case SNDRV_PCM_TRIGGER_START:
> + pr_debug("had: Trigger Start\n");
> + caps = HDMI_AUDIO_UNDERRUN | HDMI_AUDIO_BUFFER_DONE;
> + retval = query_ops->hdmi_audio_set_caps(
> + HAD_SET_ENABLE_AUDIO_INT, &caps);
> + if (retval)
> + return retval;
> + retval = query_ops->hdmi_audio_set_caps(
> + HAD_SET_ENABLE_AUDIO, NULL);
> + if (retval)
> + return retval;
Don't you need to reset audio_caps at error?
> +
> + retval = reg_ops->hdmi_audio_read_modify(AUD_CONFIG,
> + SET_BIT0, REG_BIT_0);
> + stream->substream = substream;
> + stream->stream_status = STREAM_RUNNING;
> + break;
> +
> + case SNDRV_PCM_TRIGGER_STOP:
> + pr_debug("had: Trigger Stop\n");
> + caps = HDMI_AUDIO_UNDERRUN | HDMI_AUDIO_BUFFER_DONE;
> + retval = query_ops->hdmi_audio_set_caps(
> + HAD_SET_DISABLE_AUDIO_INT, &caps);
> + if (retval)
> + return retval;
> + retval = query_ops->hdmi_audio_set_caps(
> + HAD_SET_DISABLE_AUDIO, NULL);
> + if (retval)
> + return retval;
> + stream->stream_status = STREAM_DROPPED;
> + break;
> +
> + case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> + pr_debug("had: Trigger Pause\n");
> + /* disable the validity bits */
> + for (i = 0; i < MAX_HW_BUFS; i++) {
> + retval = reg_ops->hdmi_audio_read_register(
> + AUD_BUF_A_ADDR+(i*REG_WIDTH), ®val);
> + if (retval)
> + return retval;
> + if (regval & REG_BIT_0) {
> + retval = reg_ops->hdmi_audio_read_modify(
> + AUD_BUF_A_ADDR+(i * REG_WIDTH),
> + 0, REG_BIT_0);
> + if (retval)
> + return retval;
> + intelhaddata->buf_info[HAD_BUF_TYPE_A + i].
> + is_valid = true;
> + }
> + }
> + stream->stream_status = STREAM_PAUSED;
> + break;
> +
> + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> + pr_debug("had: Trigger Resume\n");
> + /* enable the validity bits */
> + for (i = 0; i < MAX_HW_BUFS; i++) {
> + if (intelhaddata->buf_info[HAD_BUF_TYPE_A + i].is_valid)
> + retval = reg_ops->hdmi_audio_read_modify(
> + AUD_BUF_A_ADDR + (i * REG_WIDTH),
> + SET_BIT0, REG_BIT_0);
> + }
> + stream->stream_status = STREAM_RUNNING;
> + break;
> +
> + default:
> + retval = -EINVAL;
> + }
> + return retval;
> +}
> +
> +/**
> +* snd_intelhad_pcm_prepare- internal preparation before starting a stream
> +*
> +* @substream: substream for which the function is called
> +*
> +* This function is called when a stream is started for internal preparation.
> +*/
> +static int snd_intelhad_pcm_prepare(struct snd_pcm_substream *substream)
> +{
> + struct had_stream_pvt *stream;
> + int retval;
> + u32 disp_samp_freq, n_param;
> + struct snd_intelhad *intelhaddata;
> + struct snd_pcm_runtime *runtime;
> +
> + pr_debug("had: pcm_prepare called\n");
> +
> + BUG_ON(!substream);
> + runtime = substream->runtime;
> + pr_debug("had:period_size=%d\n",
> + frames_to_bytes(runtime, runtime->period_size));
> + pr_debug("had:periods=%d\n", runtime->periods);
> + pr_debug("had:buffer_size=%d\n", snd_pcm_lib_buffer_bytes(substream));
> + pr_debug("had:rate=%d\n", runtime->rate);
> + pr_debug("had:channels=%d\n", runtime->channels);
> +
> + stream = substream->runtime->private_data;
> + intelhaddata = snd_pcm_substream_chip(substream);
> + if (intelhaddata->stream_info.str_id) {
> + pr_debug("had:_prepare is called for existing str_id#%d\n",
> + intelhaddata->stream_info.str_id);
> + retval = snd_intelhad_pcm_trigger(substream,
> + SNDRV_PCM_TRIGGER_STOP);
> + return retval;
> + }
> +
> + intelhaddata->playback_cnt++;
> + intelhaddata->stream_info.str_id = intelhaddata->playback_cnt;
Note that the prepare callback might be called multiple times before
triggering. This counter doesn't work. If any, it should be counted
in the open/close callback.
> + snprintf(substream->pcm->id, sizeof(substream->pcm->id),
> + "%d", intelhaddata->stream_info.str_id);
> + retval = snd_intelhad_init_stream(substream);
> + if (retval)
> + goto prep_end;
> + /* Get N value in KHz */
> + retval = intelhaddata->query_ops->hdmi_audio_get_caps(
> + HAD_GET_SAMPLING_FREQ, &disp_samp_freq);
> + if (retval) {
> + pr_debug("had: querying display sampling freq failed\n");
> + goto prep_end;
> + } else
> + pr_debug("had: TMDS freq = %d kHz\n", disp_samp_freq);
> +
> + retval = snd_intelhad_prog_n(substream->runtime->rate, &n_param);
> + if (retval) {
> + pr_debug("had: programming N value failed\n");
> + goto prep_end;
> + }
> + retval = snd_intelhad_prog_cts(
> + substream->runtime->rate/1000, disp_samp_freq, n_param);
> + if (retval) {
> + pr_debug("had: programming CTS value failed\n");
> + goto prep_end;
> + }
> +
> + retval = snd_intelhad_prog_DIP(substream);
> + if (retval) {
> + pr_debug("had: programming DIP values failed\n");
> + goto prep_end;
> + }
> + retval = snd_intelhad_init_audio_ctrl(substream);
> + if (retval) {
> + pr_debug("had: initializing audio controller regs failed\n");
> + goto prep_end;
> + }
> + retval = snd_intelhad_prog_ring_buf(substream) ;
> + if (retval)
> + pr_debug("had: initializing ring buffer regs failed\n");
> +
> +prep_end:
> + return retval;
> +}
> +
> +/**
> + * snd_intelhad_pcm_pointer- to send the current buffer pointer processed by hw
> + *
> + * @substream: substream for which the function is called
> + *
> + * This function is called by ALSA framework to get the current hw buffer ptr
> + * when a period is elapsed
> + */
> +static snd_pcm_uframes_t snd_intelhad_pcm_pointer(
> + struct snd_pcm_substream *substream)
> +{
> + struct had_stream_pvt *stream;
> + struct snd_intelhad *intelhaddata;
> + u32 bytes_rendered;
> +
> + pr_debug("had: Called snd_intelhad_pcm_pointer\n");
> + BUG_ON(!substream);
> +
> + intelhaddata = snd_pcm_substream_chip(substream);
> + stream = substream->runtime->private_data;
> +
> + div_u64_rem(intelhaddata->stream_info.buffer_rendered,
> + intelhaddata->stream_info.ring_buf_size,
> + &(bytes_rendered));
> + intelhaddata->stream_info.buffer_ptr = bytes_to_frames(
> + substream->runtime,
> + bytes_rendered);
> + pr_debug("had:pcm_pointer = %#x\n",
> + intelhaddata->stream_info.buffer_ptr);
> + return intelhaddata->stream_info.buffer_ptr;
> +}
> +
> +/*PCM operations structure and the calls back for the same */
> +struct snd_pcm_ops snd_intelhad_playback_ops = {
Does it need to be global?
> + .open = snd_intelhad_open,
> + .close = snd_intelhad_close,
> + .ioctl = snd_pcm_lib_ioctl,
> + .hw_params = snd_intelhad_hw_params,
> + .hw_free = snd_intelhad_hw_free,
> + .prepare = snd_intelhad_pcm_prepare,
> + .trigger = snd_intelhad_pcm_trigger,
> + .pointer = snd_intelhad_pcm_pointer,
> +};
> +
> +/*
> +* alsa_card_intelhad_init- driver init function
> +* This function is called when driver module is inserted
> +*/
> +static int __init alsa_card_intelhad_init(void)
> +{
> + int retval;
> + struct had_callback_ops ops_cb;
> +
> + pr_debug("had: init called\n");
> + pr_info(KERN_INFO "INFO: ******** HAD DRIVER loading.. Ver: %s\n",
> + HAD_DRIVER_VERSION);
> +
> + /* allocate memory for saving internal context and working */
> + intelhaddata = kzalloc(sizeof(*intelhaddata), GFP_KERNEL);
> + if (!intelhaddata) {
> + pr_debug("had: mem alloc failed\n");
> + return -ENOMEM;
> + }
> + /* allocate memory for display driver api set */
> + intelhaddata->reg_ops = kzalloc(
> + sizeof(struct hdmi_audio_registers_ops),
> + GFP_KERNEL);
> + if (!intelhaddata->reg_ops) {
> + pr_debug("had: mem alloc failed\n");
> + retval = -ENOMEM;
> + goto free_context;
> + }
> + intelhaddata->query_ops = kzalloc(
> + sizeof(struct hdmi_audio_query_set_ops),
> + GFP_KERNEL);
> + if (!intelhaddata->query_ops) {
> + pr_debug("had: mem alloc failed\n");
> + retval = -ENOMEM;
> + goto free_regops;
> + }
Any reason to allocate extra two *_ops instead of just put these flat
in the structure itself? I mean,
struct intelhda {
...
struct hdmi_audio_registers_ops reg_ops;
struct hdmi_audio_query_set_ops query_ops;
...
}
then you don't need to malloc them.
> + ops_cb.intel_had_event_call_back = had_event_handler;
> + /* registering with display driver to get access to display APIs */
> + retval = intel_hdmi_audio_query_capabilities(
> + ops_cb.intel_had_event_call_back,
> + &intelhaddata->reg_ops,
> + &intelhaddata->query_ops);
> + if (retval) {
> + pr_debug("had: registering with display driver failed\n");
> + goto free_allocs;
> + }
> + pr_debug("had:...init complete\n");
> + return retval;
> +free_allocs:
> + kfree(intelhaddata->query_ops);
> +free_regops:
> + kfree(intelhaddata->reg_ops);
> +free_context:
> + kfree(intelhaddata);
> + pr_err("had: driver init failed\n");
> + return retval;
> +}
> +
> +/**
> +* alsa_card_intelhad_exit- driver exit function
> +* This function is called when driver module is removed
> +*/
> +static void __exit alsa_card_intelhad_exit(void)
> +{
> + pr_debug("had:had_exit called\n");
> + if (intelhaddata) {
> + kfree(intelhaddata->query_ops);
> + kfree(intelhaddata->reg_ops);
> + kfree(intelhaddata);
> + }
> +}
> +late_initcall(alsa_card_intelhad_init);
> +module_exit(alsa_card_intelhad_exit);
Overall I feel uneasy about the handling of global variables.
They should be cleaned up more...
thanks,
Takashi
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