[PATCH v2 2/3] ALSA: Implement the new Virtual PCM Test Driver

Ivan Orlov
2023-05-21T18:33:03Z

- Rename the driver from 'valsa' to 'pcmtest'.
- Implement support for interleaved and non-interleaved access modes
- Add support for 8 substreams and 4 channels
- Extend supported formats
- Extend and rewrite in C the selftest for the driver

MAINTAINERS | 8 +
sound/drivers/Kconfig | 16 +
sound/drivers/Makefile | 2 +
sound/drivers/pcmtest.c | 659 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 685 insertions(+)
create mode 100644 sound/drivers/pcmtest.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 27ef11624748..a16ab62ff975 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -22419,6 +22419,14 @@ L: linux-fsdevel@vger.kernel.org
S: Maintained
F: fs/vboxsf/*

+VIRTUAL PCM TEST DRIVER
+M: Ivan Orlov <ivan.orlov0322@gmail.com>
+L: alsa-devel@alsa-project.org
+S: Maintained
+F: Documentation/sound/cards/pcmtest.rst
+F: sound/drivers/pcmtest.c
+F: tools/testing/selftests/alsa/test-pcmtest-driver.c
+
VIRTUAL SERIO DEVICE DRIVER
M: Stephen Chandler Paul <thatslyude@gmail.com>
S: Maintained
diff --git a/sound/drivers/Kconfig b/sound/drivers/Kconfig
index be3009746f3a..7a0f9f409642 100644
--- a/sound/drivers/Kconfig
+++ b/sound/drivers/Kconfig
@@ -109,6 +109,22 @@ config SND_ALOOP
To compile this driver as a module, choose M here: the module
will be called snd-aloop.

+config SND_PCMTEST
+ tristate "Virtual PCM test driver"
+ select SND_PCM
+ help
+ Say 'Y' or 'M' to include support for the Virtual PCM test driver.
+ This driver is aimed at extended testing of the userspace applications
+ which use the ALSA API, as well as the PCM middle layer testing.
+
+ It can generate random or pattern-based data into the capture stream,
+ check the playback stream for containing the selected pattern, inject
+ time delays during capture/playback, redefine the RESET ioctl operation
+ to perform the PCM middle layer testing and inject errors during the
+ PCM callbacks. It supports both interleaved and non-interleaved access
+ modes. You can find the corresponding selftest in the 'alsa'
+ selftests folder.
+
config SND_VIRMIDI
tristate "Virtual MIDI soundcard"
depends on SND_SEQUENCER
diff --git a/sound/drivers/Makefile b/sound/drivers/Makefile
index b60303180a1b..2c0c7092d396 100644
--- a/sound/drivers/Makefile
+++ b/sound/drivers/Makefile
@@ -8,6 +8,7 @@ snd-dummy-objs := dummy.o
snd-aloop-objs := aloop.o
snd-mtpav-objs := mtpav.o
snd-mts64-objs := mts64.o
+snd-pcmtest-objs := pcmtest.o
snd-portman2x4-objs := portman2x4.o
snd-serial-u16550-objs := serial-u16550.o
snd-serial-generic-objs := serial-generic.o
@@ -17,6 +18,7 @@ snd-virmidi-objs := virmidi.o
obj-$(CONFIG_SND_DUMMY) += snd-dummy.o
obj-$(CONFIG_SND_ALOOP) += snd-aloop.o
obj-$(CONFIG_SND_VIRMIDI) += snd-virmidi.o
+obj-$(CONFIG_SND_PCMTEST) += snd-pcmtest.o
obj-$(CONFIG_SND_SERIAL_U16550) += snd-serial-u16550.o
obj-$(CONFIG_SND_SERIAL_GENERIC) += snd-serial-generic.o
obj-$(CONFIG_SND_MTPAV) += snd-mtpav.o
diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
new file mode 100644
index 000000000000..7b46eb415796
--- /dev/null
+++ b/sound/drivers/pcmtest.c
@@ -0,0 +1,659 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Virtual ALSA driver for PCM testing/fuzzing
+ *
+ * Copyright 2023 Ivan Orlov <ivan.orlov0322@gmail.com>
+ *
+ * This is a simple virtual ALSA driver, which can be used for audio applications/PCM middle layer
+ * testing or fuzzing.
+ * It can:
+ * - Simulate 'playback' and 'capture' actions
+ * - Generate random or pattern-based capture data
+ * - Check playback buffer for containing looped template, and notify about the results
+ * through the debugfs entry
+ * - Inject delays into the playback and capturing processes. See 'inject_delay' parameter.
+ * - Inject errors during the PCM callbacks.
+ * - Register custom RESET ioctl and notify when it is called through the debugfs entry
+ * - Work in interleaved and non-interleaved modes
+ * - Support up to 8 substreams
+ * - Support up to 4 channels
+ * - Support framerates from 8 kHz to 48 kHz
+ *
+ * When driver works in the capture mode with multiple channels, it duplicates the looped
+ * pattern to each separate channel. For example, if we have 2 channels, format = U8, interleaved
+ * access mode and pattern 'abacaba', the DMA buffer will look like aabbccaabbaaaa..., so buffer for
+ * each channel will contain abacabaabacaba... Same for the non-interleaved mode.
+ *
+ * However, it may break the capturing on the higher framerates with small period size, so it is
+ * better to choose larger period sizes.
+ *
+ * You can find the corresponding selftest in the 'alsa' selftests folder.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <sound/pcm.h>
+#include <sound/core.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/timer.h>
+#include <linux/random.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+
+#define DEVNAME "pcmtestd"
+#define CARD_NAME "pcm-test-card"
+#define TIMER_PER_SEC 5
+#define TIMER_INTERVAL (HZ / TIMER_PER_SEC)
+#define DELAY_JIFFIES HZ
+#define PLAYBACK_SUBSTREAM_CNT 8
+#define CAPTURE_SUBSTREAM_CNT 8
+#define MAX_CHANNELS_NUM 4
+
+#define FILL_MODE_RAND 0
+#define FILL_MODE_PAT 1
+
+#define MAX_PATTERN_LEN 4096
+
+static int index = -1;
+static char *id = "pcmtest";
+static bool enable = true;
+static int inject_delay;
+static bool inject_hwpars_err;
+static bool inject_prepare_err;
+static bool inject_trigger_err;
+
+static short fill_mode = FILL_MODE_PAT;
+static char fill_pattern[MAX_PATTERN_LEN] = "abacaba";
+static u32 pattern_len = 7;
+
+static u8 playback_capture_test;
+static u8 ioctl_reset_test;
+static struct dentry *driver_debug_dir;
+
+module_param(index, int, 0444);
+MODULE_PARM_DESC(index, "Index value for " CARD_NAME " soundcard");
+module_param(id, charp, 0444);
+MODULE_PARM_DESC(id, "ID string for " CARD_NAME " soundcard");
+module_param(enable, bool, 0444);
+MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");
+module_param(fill_mode, short, 0600);
+MODULE_PARM_DESC(fill_mode, "Buffer fill mode: rand(0) or pattern(1)");
+module_param(inject_delay, int, 0600);
+MODULE_PARM_DESC(inject_delay, "Inject delays during playback/capture (in jiffies)");
+module_param(inject_hwpars_err, bool, 0600);
+MODULE_PARM_DESC(inject_hwpars_err, "Inject EBUSY error in the 'hw_params' callback");
+module_param(inject_prepare_err, bool, 0600);
+MODULE_PARM_DESC(inject_prepare_err, "Inject EINVAL error in the 'prepare' callback");
+module_param(inject_trigger_err, bool, 0600);
+MODULE_PARM_DESC(inject_trigger_err, "Inject EINVAL error in the 'trigger' callback");
+
+struct pcmtst {
+ struct snd_pcm *pcm;
+ struct snd_card *card;
+ struct platform_device *pdev;
+};
+
+struct pcmtst_buf_iter {
+ size_t buf_pos; // position in the DMA buffer
+ size_t period_pos; // period-relative position
+ size_t b_rw; // Bytes to write on every timer tick
+ unsigned int sample_bytes; // sample_bits / 8
+ bool is_buf_corrupted; // playback test result indicator
+ size_t period_bytes; // bytes in a one period
+ bool interleaved; // Interleaved/Non-interleaved mode
+ size_t total_bytes; // Total bytes read/written
+ size_t chan_block; // Bytes in one channel buffer when non-interleaved
+ struct snd_pcm_substream *substream;
+ struct timer_list timer_instance;
+};
+
+static struct pcmtst *pcmtst;
+
+static struct snd_pcm_hardware snd_pcmtst_hw = {
+ .info = (SNDRV_PCM_INFO_INTERLEAVED |
+ SNDRV_PCM_INFO_BLOCK_TRANSFER |
+ SNDRV_PCM_INFO_NONINTERLEAVED |
+ SNDRV_PCM_INFO_MMAP_VALID),
+ .formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
+ .rates = SNDRV_PCM_RATE_8000_48000,
+ .rate_min = 8000,
+ .rate_max = 48000,
+ .channels_min = 1,
+ .channels_max = MAX_CHANNELS_NUM,
+ .buffer_bytes_max = 128 * 1024,
+ .period_bytes_min = 4096,
+ .period_bytes_max = 32768,
+ .periods_min = 1,
+ .periods_max = 1024,
+};
+
+static inline void inc_buf_pos(struct pcmtst_buf_iter *v_iter, size_t by, size_t bytes)
+{
+ v_iter->total_bytes += by;
+ v_iter->buf_pos += by;
+ v_iter->buf_pos %= bytes;
+}
+
+/*
+ * Position in the DMA buffer when we are in the non-interleaved mode. We increment buf_pos
+ * every time we write a byte to any channel, so the position in the current channel buffer is
+ * (position in the DMA buffer) / count_of_channels + size_of_channel_buf * current_channel
+ */
+static inline size_t buf_pos_n(struct pcmtst_buf_iter *v_iter, unsigned int channels,
+ unsigned int chan_num)
+{
+ return v_iter->buf_pos / channels + v_iter->chan_block * chan_num;
+}
+
+/*
+ * Get the count of bytes written for the current channel in the interleaved mode.
+ * This is (count of samples written for the current channel) * bytes_in_sample +
+ * (relative position in the current sample)
+ */
+static inline size_t ch_pos_i(size_t b_total, unsigned int channels, unsigned int b_sample)
+{
+ return b_total / channels / b_sample * b_sample + b_total % b_sample;
+}
+
+static void check_buf_block_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ size_t i;
+ u8 current_byte;
+
+ for (i = 0; i < v_iter->b_rw; i++) {
+ current_byte = runtime->dma_area[v_iter->buf_pos];
+ if (!current_byte)
+ break;
+ if (current_byte != fill_pattern[ch_pos_i(v_iter->total_bytes, runtime->channels,
+ v_iter->sample_bytes) % pattern_len]) {
+ v_iter->is_buf_corrupted = true;
+ break;
+ }
+ inc_buf_pos(v_iter, 1, runtime->dma_bytes);
+ }
+ // If we broke during the loop, add remaining bytes to the buffer position.
+ inc_buf_pos(v_iter, v_iter->b_rw - i, runtime->dma_bytes);
+}
+
+static void check_buf_block_ni(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ unsigned int channels = runtime->channels;
+ size_t i;
+ u8 current_byte;
+
+ for (i = 0; i < v_iter->b_rw; i++) {
+ current_byte = runtime->dma_area[buf_pos_n(v_iter, channels, i % channels)];
+ if (!current_byte)
+ break;
+ if (current_byte != fill_pattern[(v_iter->total_bytes / channels)
+ % pattern_len]) {
+ v_iter->is_buf_corrupted = true;
+ break;
+ }
+ inc_buf_pos(v_iter, 1, runtime->dma_bytes);
+ }
+ inc_buf_pos(v_iter, v_iter->b_rw - i, runtime->dma_bytes);
+}
+
+/*
+ * Check one block of the buffer. Here we iterate the buffer until we find '0'. This condition is
+ * necessary because we need to detect when the reading/writing ends, so we assume that the pattern
+ * doesn't contain zeros.
+ */
+static void check_buf_block(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ if (v_iter->interleaved)
+ check_buf_block_i(v_iter, runtime);
+ else
+ check_buf_block_ni(v_iter, runtime);
+}
+
+/*
+ * Fill buffer in the non-interleaved mode. The order of samples is C0, ..., C0, C1, ..., C1, C2...
+ * The channel buffers lay in the DMA buffer continuously (see default copy_user and copy_kernel
+ * handlers in the pcm_lib.c file).
+ *
+ * Here we increment the DMA buffer position every time we write a byte to any channel 'buffer'.
+ * We need this to simulate the correct hardware pointer moving.
+ */
+static void fill_block_pattern_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ size_t i;
+ unsigned int channels = runtime->channels;
+
+ for (i = 0; i < v_iter->b_rw; i++) {
+ runtime->dma_area[buf_pos_n(v_iter, channels, i % channels)] =
+ fill_pattern[(v_iter->total_bytes / channels) % pattern_len];
+ inc_buf_pos(v_iter, 1, runtime->dma_bytes);
+ }
+}
+
+// Fill buffer in the interleaved mode. The order of samples is C0, C1, C2, C0, C1, C2, ...
+static void fill_block_pattern_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ size_t i;
+ size_t pos_in_ch;
+
+ for (i = 0; i < v_iter->b_rw; i++) {
+ pos_in_ch = ch_pos_i(v_iter->total_bytes, runtime->channels,
+ v_iter->sample_bytes);
+
+ runtime->dma_area[v_iter->buf_pos] = fill_pattern[pos_in_ch % pattern_len];
+ inc_buf_pos(v_iter, 1, runtime->dma_bytes);
+ }
+}
+
+static void fill_block_pattern(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ if (v_iter->interleaved)
+ fill_block_pattern_i(v_iter, runtime);
+ else
+ fill_block_pattern_n(v_iter, runtime);
+}
+
+static void fill_block_rand_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ unsigned int channels = runtime->channels;
+ // Remaining space in all channel buffers
+ size_t bytes_remain = runtime->dma_bytes - v_iter->buf_pos;
+ unsigned int i;
+
+ for (i = 0; i < channels; i++) {
+ if (v_iter->b_rw <= bytes_remain) {
+ //b_rw - count of bytes must be written for all channels at each timer tick
+ get_random_bytes(runtime->dma_area + buf_pos_n(v_iter, channels, i),
+ v_iter->b_rw / channels);
+ } else {
+ // Write to the end of buffer and start from the beginning of it
+ get_random_bytes(runtime->dma_area + buf_pos_n(v_iter, channels, i),
+ bytes_remain / channels);
+ get_random_bytes(runtime->dma_area + v_iter->chan_block * i,
+ (v_iter->b_rw - bytes_remain) / channels);
+ }
+ }
+ inc_buf_pos(v_iter, v_iter->b_rw, runtime->dma_bytes);
+}
+
+static void fill_block_rand_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ size_t in_cur_block = runtime->dma_bytes - v_iter->buf_pos;
+
+ if (v_iter->b_rw <= in_cur_block) {
+ get_random_bytes(&runtime->dma_area[v_iter->buf_pos], v_iter->b_rw);
+ } else {
+ get_random_bytes(&runtime->dma_area[v_iter->buf_pos], in_cur_block);
+ get_random_bytes(runtime->dma_area, v_iter->b_rw - in_cur_block);
+ }
+ inc_buf_pos(v_iter, v_iter->b_rw, runtime->dma_bytes);
+}
+
+static void fill_block_random(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ if (v_iter->interleaved)
+ fill_block_rand_i(v_iter, runtime);
+ else
+ fill_block_rand_n(v_iter, runtime);
+}
+
+static void fill_block(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime)
+{
+ switch (fill_mode) {
+ case FILL_MODE_RAND:
+ fill_block_random(v_iter, runtime);
+ break;
+ case FILL_MODE_PAT:
+ fill_block_pattern(v_iter, runtime);
+ break;
+ }
+}
+
+/*
+ * Here we iterate through the buffer by (buffer_size / iterates_per_second) bytes.
+ * The driver uses timer to simulate the hardware pointer moving, and notify the PCM middle layer
+ * about period elapsed.
+ */
+static void timer_timeout(struct timer_list *data)
+{
+ struct pcmtst_buf_iter *v_iter;
+ struct snd_pcm_substream *substream;
+
+ v_iter = from_timer(v_iter, data, timer_instance);
+ substream = v_iter->substream;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !v_iter->is_buf_corrupted)
+ check_buf_block(v_iter, substream->runtime);
+ else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+ fill_block(v_iter, substream->runtime);
+ else
+ inc_buf_pos(v_iter, v_iter->b_rw, substream->runtime->dma_bytes);
+
+ v_iter->period_pos += v_iter->b_rw;
+ if (v_iter->period_pos >= v_iter->period_bytes) {
+ v_iter->period_pos %= v_iter->period_bytes;
+ snd_pcm_period_elapsed(substream);
+ }
+
+ mod_timer(&v_iter->timer_instance, jiffies + TIMER_INTERVAL + inject_delay);
+}
+
+static int snd_pcmtst_pcm_open(struct snd_pcm_substream *substream)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct pcmtst_buf_iter *v_iter;
+
+ v_iter = kzalloc(sizeof(*v_iter), GFP_KERNEL);
+ if (!v_iter)
+ return -ENOMEM;
+
+ runtime->hw = snd_pcmtst_hw;
+ runtime->private_data = v_iter;
+ v_iter->substream = substream;
+ v_iter->buf_pos = 0;
+ v_iter->is_buf_corrupted = false;
+ v_iter->period_pos = 0;
+ v_iter->total_bytes = 0;
+
+ playback_capture_test = 0;
+ ioctl_reset_test = 0;
+
+ timer_setup(&v_iter->timer_instance, timer_timeout, 0);
+ mod_timer(&v_iter->timer_instance, jiffies + TIMER_INTERVAL);
+ return 0;
+}
+
+static int snd_pcmtst_pcm_close(struct snd_pcm_substream *substream)
+{
+ struct pcmtst_buf_iter *v_iter = substream->runtime->private_data;
+
+ timer_shutdown_sync(&v_iter->timer_instance);
+ v_iter->substream = NULL;
+ playback_capture_test = !v_iter->is_buf_corrupted;
+ kfree(v_iter);
+ return 0;
+}
+
+static int snd_pcmtst_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct pcmtst_buf_iter *v_iter = runtime->private_data;
+
+ if (inject_trigger_err)
+ return -EINVAL;
+
+ v_iter->sample_bytes = runtime->sample_bits / 8;
+ v_iter->period_bytes = frames_to_bytes(runtime, runtime->period_size);
+ if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED ||
+ runtime->access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED) {
+ v_iter->chan_block = runtime->dma_bytes / runtime->channels;
+ v_iter->interleaved = false;
+ } else {
+ v_iter->interleaved = true;
+ }
+ // We want to record RATE * ch_cnt samples per sec, it is rate * sample_bytes * ch_cnt bytes
+ v_iter->b_rw = runtime->rate * runtime->sample_bits / 8 / TIMER_PER_SEC * runtime->channels;
+
+ return 0;
+}
+
+static snd_pcm_uframes_t snd_pcmtst_pcm_pointer(struct snd_pcm_substream *substream)
+{
+ struct pcmtst_buf_iter *v_iter = substream->runtime->private_data;
+
+ return bytes_to_frames(substream->runtime, v_iter->buf_pos);
+}
+
+static int snd_pcmtst_free(struct pcmtst *pcmtst)
+{
+ if (!pcmtst)
+ return 0;
+ kfree(pcmtst);
+ return 0;
+}
+
+// These callbacks are required, but empty - all freeing occurs in pdev_remove
+static int snd_pcmtst_dev_free(struct snd_device *device)
+{
+ return 0;
+}
+
+static void pcmtst_pdev_release(struct device *dev)
+{
+}
+
+static int snd_pcmtst_pcm_prepare(struct snd_pcm_substream *substream)
+{
+ if (inject_prepare_err)
+ return -EINVAL;
+ return 0;
+}
+
+static int snd_pcmtst_pcm_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ if (inject_hwpars_err)
+ return -EBUSY;
+ return 0;
+}
+
+static int snd_pcmtst_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+ return 0;
+}
+
+static int snd_pcmtst_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg)
+{
+ switch (cmd) {
+ case SNDRV_PCM_IOCTL1_RESET:
+ ioctl_reset_test = 1;
+ break;
+ }
+ return snd_pcm_lib_ioctl(substream, cmd, arg);
+}
+
+static const struct snd_pcm_ops snd_pcmtst_playback_ops = {
+ .open = snd_pcmtst_pcm_open,
+ .close = snd_pcmtst_pcm_close,
+ .trigger = snd_pcmtst_pcm_trigger,
+ .hw_params = snd_pcmtst_pcm_hw_params,
+ .ioctl = snd_pcmtst_ioctl,
+ .hw_free = snd_pcmtst_pcm_hw_free,
+ .prepare = snd_pcmtst_pcm_prepare,
+ .pointer = snd_pcmtst_pcm_pointer,
+};
+
+static const struct snd_pcm_ops snd_pcmtst_capture_ops = {
+ .open = snd_pcmtst_pcm_open,
+ .close = snd_pcmtst_pcm_close,
+ .trigger = snd_pcmtst_pcm_trigger,
+ .hw_params = snd_pcmtst_pcm_hw_params,
+ .hw_free = snd_pcmtst_pcm_hw_free,
+ .ioctl = snd_pcmtst_ioctl,
+ .prepare = snd_pcmtst_pcm_prepare,
+ .pointer = snd_pcmtst_pcm_pointer,
+};
+
+static int snd_pcmtst_new_pcm(struct pcmtst *pcmtst)
+{
+ struct snd_pcm *pcm;
+ int err;
+
+ err = snd_pcm_new(pcmtst->card, "PCMTest", 0, PLAYBACK_SUBSTREAM_CNT,
+ CAPTURE_SUBSTREAM_CNT, &pcm);
+ if (err < 0)
+ return err;
+ pcm->private_data = pcmtst;
+ strcpy(pcm->name, "PCMTest");
+ pcmtst->pcm = pcm;
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_pcmtst_playback_ops);
+ snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_pcmtst_capture_ops);
+
+ err = snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, &pcmtst->pdev->dev,
+ 0, 128 * 1024);
+ return err;
+}
+
+static int snd_pcmtst_create(struct snd_card *card, struct platform_device *pdev,
+ struct pcmtst **r_pcmtst)
+{
+ struct pcmtst *pcmtst;
+ int err;
+ static const struct snd_device_ops ops = {
+ .dev_free = snd_pcmtst_dev_free,
+ };
+
+ pcmtst = kzalloc(sizeof(*pcmtst), GFP_KERNEL);
+ if (!pcmtst)
+ return -ENOMEM;
+ pcmtst->card = card;
+ pcmtst->pdev = pdev;
+
+ err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, pcmtst, &ops);
+ if (err < 0)
+ goto _err_free_chip;
+
+ err = snd_pcmtst_new_pcm(pcmtst);
+ if (err < 0)
+ goto _err_free_chip;
+
+ *r_pcmtst = pcmtst;
+ return 0;
+
+_err_free_chip:
+ snd_pcmtst_free(pcmtst);
+ return err;
+}
+
+static int pcmtst_probe(struct platform_device *pdev)
+{
+ struct snd_card *card;
+ int err;
+
+ err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+ if (err)
+ return err;
+
+ err = snd_devm_card_new(&pdev->dev, index, id, THIS_MODULE, 0, &card);
+ if (err < 0)
+ return err;
+ err = snd_pcmtst_create(card, pdev, &pcmtst);
+ if (err < 0)
+ return err;
+
+ strcpy(card->driver, "PCM-TEST Driver");
+ strcpy(card->shortname, "PCM-Test");
+ strcpy(card->longname, "PCM-Test virtual driver");
+
+ err = snd_card_register(card);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static int pdev_remove(struct platform_device *dev)
+{
+ snd_pcmtst_free(pcmtst);
+ return 0;
+}
+
+static struct platform_device pcmtst_pdev = {
+ .name = "pcmtest",
+ .dev.release = pcmtst_pdev_release,
+};
+
+static struct platform_driver pcmtst_pdrv = {
+ .probe = pcmtst_probe,
+ .remove = pdev_remove,
+ .driver = {
+ .name = "pcmtest",
+ },
+};
+
+static ssize_t pattern_write(struct file *file, const char __user *buff, size_t len, loff_t *off)
+{
+ ssize_t to_write = len;
+
+ if (*off + to_write > MAX_PATTERN_LEN)
+ to_write = MAX_PATTERN_LEN - *off;
+
+ // Crop silently everything over the buffer
+ if (to_write <= 0)
+ return len;
+
+ if (copy_from_user(fill_pattern + *off, buff, to_write))
+ return -EFAULT;
+ pattern_len = *off + to_write;
+ *off += to_write;
+
+ return to_write;
+}
+
+static ssize_t pattern_read(struct file *file, char __user *buff, size_t len, loff_t *off)
+{
+ ssize_t to_read = len;
+
+ if (*off + to_read >= MAX_PATTERN_LEN)
+ to_read = MAX_PATTERN_LEN - *off;
+ if (to_read <= 0)
+ return 0;
+
+ if (copy_to_user(buff, fill_pattern + *off, to_read))
+ to_read = 0;
+ else
+ *off += to_read;
+
+ return to_read;
+}
+
+static const struct file_operations fill_pattern_fops = {
+ .read = pattern_read,
+ .write = pattern_write,
+};
+
+static int init_debug_files(void)
+{
+ driver_debug_dir = debugfs_create_dir("pcmtest", NULL);
+ if (IS_ERR(driver_debug_dir))
+ return PTR_ERR(driver_debug_dir);
+ debugfs_create_u8("pc_test", 0444, driver_debug_dir, &playback_capture_test);
+ debugfs_create_u32("pattern_len", 0444, driver_debug_dir, &pattern_len);
+ debugfs_create_u8("ioctl_test", 0444, driver_debug_dir, &ioctl_reset_test);
+ debugfs_create_file("fill_pattern", 0600, driver_debug_dir, NULL, &fill_pattern_fops);
+
+ return 0;
+}
+
+static void clear_debug_files(void)
+{
+ debugfs_remove_recursive(driver_debug_dir);
+}
+
+static int __init mod_init(void)
+{
+ int err = 0;
+
+ err = init_debug_files();
+ if (err)
+ return err;
+ err = platform_device_register(&pcmtst_pdev);
+ if (err)
+ return err;
+ err = platform_driver_register(&pcmtst_pdrv);
+ if (err)
+ platform_device_unregister(&pcmtst_pdev);
+ return err;
+}
+
+static void __exit mod_exit(void)
+{
+ clear_debug_files();
+
+ platform_driver_unregister(&pcmtst_pdrv);
+ platform_device_unregister(&pcmtst_pdev);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ivan Orlov");
+module_init(mod_init);
+module_exit(mod_exit);
--
2.34.1